67 results on '"Jessica A Gaskin"'
Search Results
2. Evaluation of a prototype detector for the LargE Area burst Polarimeter (LEAP)
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Jessica A. Gaskin, James M. Ryan, P. A. Jenke, Steven J. Sturner, Robert D. Preece, Mark L. McConnell, Peter F. Bloser, Eric Grove, Karla Oñate Melecio, Péter Veres, Colleen A. Wilson-Hodge, John Krizmanic, W. Thomas Vestrand, Jason S. Legere, Adam Goldstein, Camden Ertley, Marc Kippen, Michael S. Briggs, Daniel Kocevski, Michelle Hui, Chip Meegan, and Fabian Kislat
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Physics ,Physics::Instrumentation and Detectors ,business.industry ,Astrophysics::High Energy Astrophysical Phenomena ,Detector ,Astrophysics::Instrumentation and Methods for Astrophysics ,Polarimetry ,Compton scattering ,Polarimeter ,Scintillator ,Polarization (waves) ,Optics ,Calibration ,Gamma-ray burst ,business - Abstract
The LargE Area burst Polarimeter (LEAP) is one of two NASA Missions of Opportunity proposals that are currently in a Phase A Concept Study, with a final selection due later this year. It is a wide Field of View (FoV) Compton polarimeter designed to study Gamma-Ray Burst (GRB) polarization over the energy range from 50- 500 keV and to measure GRB spectra in the range from 20 keV - 5 MeV. During the Phase A Concept Study, lab measurements were conducted with a small-scale (5x5) prototype polarimeter module. This included both spectral and polarization measurements with laboratory calibration sources. Here the prototype measurements and the comparisons made with simulations of the prototype detector are described. These results demonstrate the basic functionality of the LEAP design.
- Published
- 2021
3. The LargE Area burst Polarimeter (LEAP) – A NASA mission of opportunity for the ISS
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Merlin Kole, Péter Veres, Fabian Kislat, W. Thomas Vestrand, Camden Ertley, John Krizmanic, Mark Pearce, Sheila McBreen, Michelle Hui, Adam Goldstein, Charles A. Meegan, Neil Martin, Bing Zhang, Donald McQueen, Gregory Fletcher, James M. Ryan, Colleen A. Wilson-Hodge, Dieter H. Hartmann, Robert D. Preece, Peter F. Bloser, Jessica A. Gaskin, Matthew G. Baring, R. Marc Kippen, Daniel Kocevski, Michael S. Briggs, J. Eric Grove, Jason S. Legere, P. A. Jenke, Karla Oñate-Melecio, Karen Gelmis, Tyson Littenberg, Steven J. Sturner, Mark L. McConnell, and Nicolas Produit
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Physics ,Scintillation ,Physics::Instrumentation and Detectors ,Payload ,Astrophysics::High Energy Astrophysical Phenomena ,International Space Station ,Astrophysics::Instrumentation and Methods for Astrophysics ,Compton scattering ,Polarimetry ,Astronomy ,Polarimeter ,Scintillator ,Gamma-ray burst - Abstract
The LargE Area Burst Polarimeter (LEAP) will radically improve our understanding of some of the most energetic phenomena in our Universe by exposing the underlying physics that governs astrophysical jets and the extreme environment surrounding newborn compact objects. LEAP will do this by making the highest fidelity polarization measurements to date of the prompt gamma-ray emission from a large sample of Gamma-Ray Bursts (GRBs). The science objectives are met with a single instrument deployed as an external payload on the ISS – a wide FOV Compton polarimeter that measures GRB polarization from 50–500 keV and GRB spectra from ~10 keV to 5 MeV. LEAP measures polarization using seven independent polarimeter modules, each with a 12x12 array of optically isolated high-Z and low-Z scintillation detectors readout by individual PMTs. LEAP is one of two NASA Missions of Opportunity proposals that are currently in a Phase A Concept Study, with a final selection due later this year.
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- 2021
4. Toward Large-Area Sub-Arcsecond X-Ray Telescopes II
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Stephen L ODell, Ryan Allured, Andrew O Ames, Michael P Biskach, David M Broadway, Ricardo J Bruni, David Burrows, Jian Cao, Brandon D Chalifoux, Kai-wing Chan, Yip-Wah Chung, Vincenzo Cotroneo, Ronald F Elsner, Jessica A Gaskin, Mikhail V Gubarev, Ralf K Heilmann, Edward Hertz, Thomas N Jackson, Kiranmayee Kilaru, Jeffery J Kolodziejczak, Ryan S McClelland, Brian D Ramsey, Paul B Reid, Raul E Riveros, Jacqueline M Roche, Suzanne E Romaine, Timo T Saha, Mark L Schattenburg, Daniel A Schwartz, Eric D Schwartz, Peter M Solly, Susan E Trolier-McKinstry, Mellville P Ulmer, Alexey Vikhlilin, Margeaux L Wallace, and William W Zhang
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Astronomy ,Optics - Abstract
In order to advance significantly scientific objectives, future x-ray astronomy missions will likely call for x-ray telescopes with large aperture areas (approx. = 3 sq m) and fine angular resolution (approx. = 1"). Achieving such performance is programmatically and technologically challenging due to the mass and envelope constraints of space-borne telescopes and to the need for densely nested grazing-incidence optics. Such an x-ray telescope will require precision fabrication, alignment, mounting, and assembly of large areas (approx. = 600 sq m) of lightweight (approx. = 2 kg/sq m areal density) high-quality mirrors, at an acceptable cost (approx. = 1 M$/sq m of mirror surface area). This paper reviews relevant programmatic and technological issues, as well as possible approaches for addressing these issues-including direct fabrication of monocrystalline silicon mirrors, active (in-space adjustable) figure correction of replicated mirrors, static post-fabrication correction using ion implantation, differential erosion or deposition, and coating-stress manipulation of thin substrates.
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- 2016
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5. Full-shell x-ray optics development at NASA Marshall Space Flight Center
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Stephen L. O'Dell, Kiranmayee Kilaru, Jessica A. Gaskin, Patrick Champey, Jacqueline M. Davis, Martin C. Weisskopf, Brian D. Ramsey, Ronald F. Elsner, David M. Broadway, Samantha A. Johnson, S. Bongiorno, Oliver J. Roberts, Wayne H. Baumgartner, Jeffrey Kolodziejczak, and Douglas A. Swartz
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Engineering ,Fabrication ,business.industry ,Mechanical Engineering ,Shell (computing) ,X-ray optics ,Polishing ,Astronomy and Astrophysics ,X-ray telescope ,Diamond turning ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Metrology ,010309 optics ,Development (topology) ,Space and Planetary Science ,Control and Systems Engineering ,0103 physical sciences ,Aerospace engineering ,business ,010303 astronomy & astrophysics ,Instrumentation - Abstract
NASA’s Marshall Space Flight Center (MSFC) maintains an active research program toward the development of high-resolution, lightweight, grazing-incidence x-ray optics to serve the needs of future x-ray astronomy missions such as Lynx. MSFC development efforts include both direct fabrication (diamond turning and deterministic computer-controlled polishing) of mirror shells and replication of mirror shells (from figured, polished mandrels). Both techniques produce full-circumference monolithic (primary + secondary) shells that share the advantages of inherent stability, ease of assembly, and low production cost. However, to achieve high-angular resolution, MSFC is exploring significant technology advances needed to control sources of figure error including fabrication- and coating-induced stresses and mounting-induced distortions.
- Published
- 2020
6. Field modeling and ray-tracing of a miniature scanning electron microscope beam column
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Don A. Gregory, Jessica A. Gaskin, and Jody S. Loyd
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010302 applied physics ,Diffraction ,Materials science ,business.industry ,Scanning electron microscope ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Space charge ,Ray tracing (physics) ,Optics ,Electron optics ,0103 physical sciences ,Chromatic aberration ,0210 nano-technology ,business ,Instrumentation ,Boundary element method ,Fourier series - Abstract
A miniature scanning electron microscope (SEM) focusing column design is introduced and its potential performance assessed through an estimation of parameters that affect the probe radius, to include source size, spherical and chromatic aberration, diffraction and space charge broadening. The focusing column, a critical component of any SEM capable of operating on the lunar surface, was developed by the NASA Marshall Space Flight Center and Advanced Research Systems. The ray-trace analysis presented uses a model of the electrostatic field (within the focusing column) that is first calculated using the boundary element method (BEM). This method provides flexibility in modeling the complex electrode shapes of practical electron lens systems. A Fourier series solution of the lens field is then derived within a cylindrical domain whose boundary potential is provided by the BEM. Used in this way, the Fourier series solution is an accuracy enhancement to the BEM solution, allowing sufficient precision to assess geometric aberrations through direct ray-tracing. Two modes of operation with distinct lens field solutions are described.
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- 2017
7. The Lynx X-ray Observatory: revealing the invisible universe
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Douglas A. Swartz, Kevin S. McCarley, Daniel A. Schwartz, Grant R. Tremblay, Alexey Vikhlinin, Harvey Tananbaum, Eric D. Schwartz, Karen Gelmis, Jessica A. Gaskin, Mark D. Freeman, and A. Domínguez
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X-ray astronomy ,Mission operations ,Exploit ,Computer science ,Observatory ,media_common.quotation_subject ,Systems engineering ,X-ray telescope ,Architecture ,Baseline (configuration management) ,Universe ,media_common - Abstract
We have been studying Lynx, an X-ray Observatory with factors of 10 to 1000 greater imaging and spectroscopic capabilities than any other existing or planned facility. We present a Design Reference Mission (DRM) driven by the need to solve fundamental problems in three broad areas of astrophysics. The Lynx Observatory will provide discovery space for all of astrophysics, and also address questions which will only be revealed as our knowledge increases. Studies supported by the Advanced Concepts Office at MSFC for the observatory design and operations take advantage of the highly successful architecture of the Chandra Observatory. A light-weight mirror with 30 times the Chandra effective area, and modern microcalorimeter and CMOS based X-ray imagers will exploit the 0.5 arcsec imaging capability. Operating at Sun/Earth L2, we expect 85% to 90% of the time to be spent acquiring data from celestial targets. Designed for a five year baseline mission, there are no expected impediments to achieving a 20 year goal. This paper presents technical details of the Observatory and highlights of the mission operations.
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- 2019
8. Demonstration of resolving power λ/Δλ 10,000 for a space-based x-ray transmission grating spectrometer
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Jessica A. Gaskin, Mark L. Schattenburg, Jeffery J. Kolodziejczak, Ralf K. Heilmann, and Alexander R. Bruccoleri
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Physics ,Diffraction ,Spectrometer ,business.industry ,Stray light ,Physics::Optics ,X-ray optics ,Grating ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,010309 optics ,Laser linewidth ,Wavelength ,Optics ,0103 physical sciences ,Electrical and Electronic Engineering ,business ,Engineering (miscellaneous) ,Diffraction grating - Abstract
We present measurements of the resolving power of a soft x-ray spectrometer consisting of 200 nm period lightweight, alignment-insensitive critical-angle transmission (CAT) gratings and a lightweight slumped-glass Wolter-I focusing mirror pair. We measure and model contributions from source, mirrors, detector pixel size, and grating period variation to the natural linewidth spectrum of the Al-K α 1 α 2 doublet. Measuring up to the 18th diffraction order, we consistently obtain small broadening due to gratings corresponding to a minimum effective grating resolving power Rg>10,000 with 90% confidence. Upper limits are often compatible with Rg=∞. Independent fitting of different diffraction orders, as well as ensemble fitting of multiple orders at multiple wavelengths, gives compatible results. Our data leads to uncertainties for the Al-Kα doublet linewidth and line separation parameters two to three times smaller than values found in the literature. Data from three different gratings are mutually compatible. This demonstrates that CAT gratings perform in excess of the requirements for the Arcus Explorer mission and are suitable for next-generation space-based x-ray spectrometer designs with resolving power five to 10 times higher than the transmission grating spectrometer onboard the Chandra X-ray Observatory.
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- 2019
9. Overview of the High-Definition X-ray Imager instrument on the Lynx x-ray surveyor
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Abraham D. Falcone, Jessica A. Gaskin, Marshall W. Bautz, Ralph P. Kraft, John A. Mulqueen, and Douglas A. Swartz
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Computer science ,Event (computing) ,Mechanical Engineering ,Antenna aperture ,Detector ,X-ray detector ,FOS: Physical sciences ,Astronomy and Astrophysics ,Frame rate ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,010309 optics ,Sensor array ,Space and Planetary Science ,Control and Systems Engineering ,0103 physical sciences ,Angular resolution ,Astrophysics - Instrumentation and Methods for Astrophysics ,010303 astronomy & astrophysics ,Instrumentation ,Image resolution ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,Remote sensing - Abstract
Four NASA Science and Technology Definition Teams have been convened in order to develop and study four mission concepts to be evaluated by the upcoming 2020 Decadal Survey. The Lynx x-ray surveyor mission is one of these four large missions. Lynx will couple fine angular resolution (, 6 pages, 5 figures, published in Journ. of Astron. Telescopes, Instruments, and Systems. arXiv admin note: substantial text overlap with arXiv:1807.05282
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- 2019
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10. Application of Silicon Photomultipliers to Compton-scattering-type Polarimeters for Gamma Ray Bursts
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Y. Saito, S. Kodaira, Takeshi Nakamori, Tatsuya Sawano, Tatehiro Mihara, S. Gunji, Shunsuke Kurosawa, Jessica A. Gaskin, and Daisuke Yonetoku
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Physics ,Physics::Instrumentation and Detectors ,business.industry ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Instrumentation and Methods for Astrophysics ,Compton scattering ,Polarimeter ,Radiation ,Scintillator ,Optics ,Silicon photomultiplier ,business ,Gamma-ray burst ,Radiation hardening ,Dark current - Abstract
Gamma-ray bursts (GRBs) are the most energetic phenomena in the universe. To elucidate the radiation mechanism of GRBs, we are developing a Compton-scattering-type polarimeter using a plastic scintillator and CsI(Tl) scintillator attached to a silicon photomultiplier (SiPM). We constructed a small test model and investigated the basic performance. Moreover, irradiating the SiPM with protons, the radiation hardness has been also investigated. From these experiments, we have recognized that the Compton-scattering-type polarimeter will obtain the sensitivity to the energy above approximately 30 keV if the radiation damage to the SiPM is not serious. On the other hand, the dark current of the SiPM becomes several thousand times higher for a few krad of irradiation and can be accumulated in the space environment in a few years. This means that the polarimeter will work well in balloon-borne experiments for a few weeks.
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- 2018
11. The Lynx X-ray Observatory: concept study overview and status
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Daniel A. Schwartz, A. Domínguez, Karen Gelmis, John A. Mulqueen, William R. Purcell, Alexey Vikhlinin, Jessica A. Gaskin, Douglas A. Swartz, Kevin S. McCarley, Gary H. Blackwood, Feryal Özel, Lynn Allen, Jonathan W. Arenberg, and Harvey Tananbaum
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X-ray astronomy ,Supermassive black hole ,Computer science ,Habitability ,Astronomy ,01 natural sciences ,Redshift ,Galaxy ,010309 optics ,Planet ,Observatory ,0103 physical sciences ,010303 astronomy & astrophysics ,Galaxy cluster - Abstract
Lynx, one of four strategic mission concepts under study for the 2020 Astrophysics Decadal Survey, will provide leaps in capability over previous and planned X-ray missions, and will provide synergistic observations in the 2030s to a multitude of space- and ground-based observatories across all wavelengths. Lynx will have orders of magnitude improvement in sensitivity, on-axis sub-arcsecond imaging with arcsecond angular resolution over a large field of view, and high-resolution spectroscopy for point-like and extended sources. The Lynx architecture enables a broad range of unique and compelling science, to be carried out mainly through a General Observer Program. This Program is envisioned to include detecting the very first supermassive black holes, revealing the high-energy drivers of galaxy and structure formation, characterizing the mechanisms that govern stellar activity - including effects on planet habitability, and exploring the highest redshift galaxy clusters. An overview and status of the Lynx concept are summarized.
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- 2018
12. Initial jitter analysis of Lynx, a proposed future large astrophysics facility
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J. Brent Knight, Jessica A. Gaskin, Jay Garcia, and A. Domínguez
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Large field of view ,Disturbance (geology) ,Computer science ,X-ray telescope ,Astrophysics ,Cryopump ,Line-of-sight propagation ,Throughput (business) ,Reaction wheel ,Jitter - Abstract
Lynx, formerly known as the X-Ray surveyor, is one of the large strategic mission concepts being studied for input into the 2020 Astrophysics Decadal Survey. Lynx is the first future X-ray mission concept planning to match Chandra's angular-resolution and will combine this with very high throughput, large field of view, and high-resolution spectroscopy for point-like and extended sources. These ambitious performance requirements clearly merit early detailed engineering to demonstrate feasibility. An on-going structural dynamic analysis is being performed on the Lynx structural design to predict dynamic responses, jitter, to expected on-board vibrational disturbances. Applicable disturbance sources include a cryogenic pump, and six reaction wheels. The structural design, disturbances, analysis, and results are presented. Ultimately, responses will be compared to Lynx performance requirements as they relate to a system error budget.
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- 2018
13. The high definition x-ray imager (HDXI) instrument on the Lynx X-ray Surveyor
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John A. Mulqueen, D. Swartz, Abraham D. Falcone, Marshall W. Bautz, Ralph P. Kraft, and Jessica A. Gaskin
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Computer science ,Detector ,Antenna aperture ,FOS: Physical sciences ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Frame rate ,01 natural sciences ,Wide field ,010309 optics ,Sensor array ,0103 physical sciences ,High definition ,Angular resolution ,Astrophysics - Instrumentation and Methods for Astrophysics ,0210 nano-technology ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,Remote sensing - Abstract
The Lynx X-ray Surveyor Mission is one of 4 large missions being studied by NASA Science and Technology Definition Teams as mission concepts to be evaluated by the upcoming 2020 Decadal Survey. By utilizing optics that couple fine angular resolution (, proceedings of SPIE Astronomical Telescopes + Instrumentation (10699-37)
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- 2018
14. X-ray verification of an optically aligned off-plane grating module
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Casey T. DeRoo, Jeffery J. Kolodziejczak, James H. Tutt, Randall L. McEntaffer, Benjamin D. Donovan, Ryan Allured, and Jessica A. Gaskin
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Diffraction ,Materials science ,Spectrometer ,business.industry ,Antenna aperture ,X-ray optics ,Grating ,Diffraction efficiency ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Metrology ,010309 optics ,Optics ,0103 physical sciences ,Electrical and Electronic Engineering ,business ,010303 astronomy & astrophysics ,Engineering (miscellaneous) ,Diffraction grating - Abstract
Off-plane x-ray reflection gratings are theoretically capable of achieving high resolution and high diffraction efficiencies over the soft x-ray bandpass, making them an ideal technology to implement on upcoming x-ray spectroscopy missions. To achieve high effective area, these gratings must be aligned into grating modules. X-ray testing was performed on an aligned grating module to assess the current optical alignment methods. Results indicate that the grating module achieved the desired alignment for an upcoming x-ray spectroscopy suborbital rocket payload with modest effective area and resolving power. These tests have also outlined a pathway towards achieving the stricter alignment tolerances of future x-ray spectrometer payloads, which require improvements in alignment metrology, grating fabrication, and testing techniques.
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- 2018
15. Lynx Mission concept status
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Mitchell A. Rodriguez, Tyrone M. Boswell, William W. Zhang, Feryal Özel, A. Falcone, Wonsik Yoon, Randall C. Hopkins, Kai Wing Chan, Julian Walker, Ralf K. Heilmann, Jay Garcia, Ryan Allured, Justin W. Rowe, Simon R. Bandler, Peter M. Solly, John A. Mulqueen, Steven Sutherlin, Marta Civitani, Karen Gelmis, Michael Baysinger, Leo L. Fabisinski, Andrew Schnell, Mark L. Schattenburg, Raul E. Riveros, Marshall W. Bautz, Thomas N. Jackson, Peter Capizzo, Daniel A. Schwartz, Lester M. Cohen, Michael J. Dipirro, P. Reid, Kiranmayee Kilaru, Douglas A. Swartz, Kevin S. McCarley, Vincenzo Cotroneo, Tianning Liu, A. Domínguez, Jessica A. Gaskin, Robert M. Suggs, Timo T. Saha, James H. Tutt, S. Basso, R. S. McClelland, Giovanni Pareschi, Susan Trolier-McKinstry, Alexey Vikhlinin, Randy L. McEntaffer, Michael P. Biskach, Jacqueline M. Davis, R. P. Kraft, Enectali Figueroa-Feliciano, and Casey T. DeRoo
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Prioritization ,Physics ,Spacecraft ,business.industry ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astronomy ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Planetary system ,01 natural sciences ,Galaxy ,law.invention ,010309 optics ,Telescope ,Stars ,Observatory ,law ,0103 physical sciences ,Concept Status ,business ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics - Abstract
Lynx is a concept under study for prioritization in the 2020 Astrophysics Decadal Survey. Providing orders of magnitude increase in sensitivity over Chandra, Lynx will examine the first black holes and their galaxies, map the large-scale structure and galactic halos, and shed new light on the environments of young stars and their planetary systems. In order to meet the Lynx science goals, the telescope consists of a high-angular resolution optical assembly complemented by an instrument suite that may include a High Definition X-ray Imager, X-ray Microcalorimeter and an X-ray Grating Spectrometer. The telescope is integrated onto the spacecraft to form a comprehensive observatory concept. Progress on the formulation of the Lynx telescope and observatory configuration is reported in this paper.
- Published
- 2017
16. Modeling and measuring charge sharing in hard x-ray imagers using HEXITEC CdTe detectors
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Andrew Inglis, Paul Seller, Daniel Ryan, Matthew D. Wilson, Jessica A. Gaskin, Steven Christe, Albert Y. Shih, and Wayne H. Baumgartner
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Physics ,Imaging spectroscopy ,Photon ,Pixel ,business.industry ,Distortion ,X-ray detector ,Optoelectronics ,Spectral resolution ,business ,Image resolution ,Charge sharing - Abstract
The Rutherford Appleton Laboratory’s HEXITEC ASIC has been designed to provide fine pixelated X-ray spectroscopic imaging in combination with a CdTe or CZT detector layer. Although HEXITEC’s small pixels enable higher spatial resolution as well as higher spectral resolution via the small-pixel effect, they also increase the probability of charge sharing, a process which degrades spectral performance by dividing the charge induced by a single photon among multiple pixels. In this paper, we investigate the effect of this process on a continuum X-ray spectrum below the Cd and Te fluorescence energies (23 keV). This is done by comparing laboratory measurements with simulations performed with a custom designed model of the HEXITEC ASIC. We find that the simulations closely match the observations implying that we have an adequate understanding of both charge sharing and the HEXITEC ASIC itself. These results can be used to predict the distortion of a spectrum measured with HEXITEC and will help determine to what extent it can be corrected. They also show that models like this one are important tools in developing and interpreting observations from ASICs like HEXITEC.
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- 2017
17. Preface
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Jessica A. Gaskin, Shaul Hanany, and Eliot F. Young
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Astronomy and Astrophysics ,Instrumentation - Published
- 2017
18. Critical-angle transmission grating technology development for high resolving power soft x-ray spectrometers on Arcus and Lynx
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Stephen L. O'Dell, Peter Cheimetz, Gisela Hartner, Jungki Song, Marlis-Madeleine La Caria, Mark L. Schattenburg, Jeffery J. Kolodziejczak, Jessica A. Gaskin, Ralf K. Heilmann, Alexander R. Bruccoleri, Edward Hertz, Vadim Burwitz, and Randall K. Smith
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010302 applied physics ,Diffraction ,Physics ,Spectrometer ,business.industry ,Antenna aperture ,Grating ,Diffraction efficiency ,01 natural sciences ,7. Clean energy ,010309 optics ,Optics ,0103 physical sciences ,Figure of merit ,Angular resolution ,business ,Diffraction grating - Abstract
Soft x-ray spectroscopy with high resolving power (R = λ/Δλ) and large effective area (A) addresses numerous unanswered science questions about the physical laws that lead to the structure of our universe. In the soft x-ray band R > 1000 can currently only be achieved with diffraction grating-based spectroscopy. Criticalangle transmission (CAT) gratings combine the advantages of blazed reflection gratings (high efficiency, use of higher diffraction orders) with those of conventional transmission gratings (relaxed alignment tolerances and temperature requirements, transparent at higher energies, low mass), resulting in minimal mission resource requirements, while greatly improving figures of merit. Diffraction efficiency > 33% and R > 10, 000 have been demonstrated for CAT gratings. Last year the technology has been certified at Technology Readiness Level 4 based on a probe class mission concept. The Explorer-scale (A > 450 cm2 , R > 2500) grating spectroscopy Arcus mission can be built with today's CAT grating technology and has been selected in the current Explorer round for a Phase A concept study. Its figure of merit for the detection of weak absorption lines will be an order of magnitude larger than current instruments on Chandra and XMM-Newton. Further CAT grating technology development and improvements in the angular resolution of x-ray optics can provide another order of magnitude improvement in performance, as is envisioned for the X-ray Surveyor/Lynx mission concept currently under development for input into the 2020 Decadal Survey. For Arcus we have tested CAT gratings in a spectrometer setup in combination with silicon pore optics (SPO) and obtained resolving power results that exceed Arcus requirements before and after environmental testing of the gratings. We have recently fabricated the largest (32 mm x 32 mm) CAT gratings to date, and plan to increase grating size further. We mounted two of these large gratings to frames and aligned them in the roll direction using a laser-based technique. Simultaneous x-ray illumination of both gratings with an SPO module demonstrated that we can exceed Arcus grating-to-grating alignment requirements without x rays.
- Published
- 2017
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19. Evaluation of a bread board model gamma-ray burst polarimeter toward installation on the international space station
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Tatsuya Kishikawa, Hiromitsu Takahashi, Shunji Kishimoto, Jason S. Legere, Takeshi Nakamori, Yuji Kishimoto, T. Sakamoto, Kiyoshi Hayashida, Kenji Toma, Peter F. Bloser, Mika Takakura, Jessica A. Gaskin, Robert D. Preece, Tatehiro Mihara, Shuichi Gunji, Mark L. McConnell, Daisuke Yonetoku, Stephen Daigle, Yuma Oikawa, Yoichi Yatsu, Colleen A. Wilson-Hodge, Tatsuya Ueda, and Brian D. Ramsey
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Physics ,Photomultiplier ,Photon ,Physics::Instrumentation and Detectors ,010308 nuclear & particles physics ,business.industry ,Gamma ray ,Polarimeter ,Scintillator ,Radiation ,Avalanche photodiode ,01 natural sciences ,Optics ,0103 physical sciences ,Calibration ,business ,010303 astronomy & astrophysics - Abstract
To elucidate the radiation mechanism of gamma ray bursts, we are developing the polarimeter which consists of segmented plastic scintillators and GAGG(Ce) scintillators attached with multi-anode photomultipliers and avalanche photodiodes, respectively. Constructing the bread board model with 36 pieces of plastic scintillator and 24 pieces of GAGG(Ce) scintillator, we have carried out the beam experiments at the KEK Photon Factory in Japan. At the same time, we carried out also computer simulation and we compared the experimental data with results of simulations. As the results, it was recognized that the modulation factor by the experiments is consistent with that by the simulations. On the other hand, though the detection efficiency obtained by the experiments is in rough agreement with that by the simulation, the value of the detection efficiency can not be well explained reasonably. This discrepancy is likely due to the incomplete energy calibration of the plastic scintillators.
- Published
- 2016
20. Special Section Guest Editorial: Lynx X-Ray Observatory
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Alexey Vikhlinin, Douglas A. Swartz, Jessica A. Gaskin, and Feryal Özel
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Physics ,Galactic astronomy ,Mechanical Engineering ,James Webb Space Telescope ,X-ray detector ,X-ray ,Astronomy ,Astronomy and Astrophysics ,Electronic, Optical and Magnetic Materials ,Space and Planetary Science ,Control and Systems Engineering ,Observatory ,Special section ,Spectroscopy ,Instrumentation - Published
- 2019
21. Lynx X-Ray Observatory: an overview
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Douglas A. Swartz, Jonathan W. Arenberg, Mark L. Schattenburg, Jessica A. Gaskin, Harvey Tananbaum, Eric D. Schwartz, William R. Purcell, A. Falcone, Randall L. McEntaffer, Kiranmayee Kilaru, Daniel A. Schwartz, William W. Zhang, Paul B. Reid, Mark D. Freeman, M. Civitani, Kevin S. McCarley, Megan E. Eckart, Simon R. Bandler, Giovanni Pareschi, Alexey Vikhlinin, Hans Moritz Günther, Mark W. Bautz, Ralph P. Kraft, Grant R. Tremblay, Feryal Özel, A. Domínguez, John ZuHone, Enectali Figueroa-Feliciano, Keith A. Havey, Karen Gelmis, and Ralf K. Heilmann
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Scientific instrument ,Large field of view ,Galactic astronomy ,Computer science ,Mechanical Engineering ,Space operations ,Astronomy ,Astronomy and Astrophysics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,010309 optics ,Space and Planetary Science ,Control and Systems Engineering ,Observatory ,0103 physical sciences ,Galaxy formation and evolution ,Angular resolution ,010303 astronomy & astrophysics ,Instrumentation ,Stellar evolution - Abstract
Lynx, one of the four strategic mission concepts under study for the 2020 Astrophysics Decadal Survey, provides leaps in capability over previous and planned x-ray missions and provides synergistic observations in the 2030s to a multitude of space- and ground-based observatories across all wavelengths. Lynx provides orders of magnitude improvement in sensitivity, on-axis subarcsecond imaging with arcsecond angular resolution over a large field of view, and high-resolution spectroscopy for point-like and extended sources in the 0.2- to 10-keV range. The Lynx architecture enables a broad range of unique and compelling science to be carried out mainly through a General Observer Program. This program is envisioned to include detecting the very first seed black holes, revealing the high-energy drivers of galaxy formation and evolution, and characterizing the mechanisms that govern stellar evolution and stellar ecosystems. The Lynx optics and science instruments are carefully designed to optimize the science capability and, when combined, form an exciting architecture that utilizes relatively mature technologies for a cost that is compatible with the projected NASA Astrophysics budget.
- Published
- 2019
22. First results from a next-generation off-plane X-ray diffraction grating
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Ryan S. McClelland, Andrew D. Holland, Casey T. DeRoo, James H. Tutt, Randall L. McEntaffer, Xinpeng Wang, Stephen L. O'Dell, Kai Wing Chan, Ted Schultz, Jessica A. Gaskin, Jeffrey Kolodziejczak, Larry Koecher, Dmitri Iazikov, Michael P. Biskach, Brennan Gantner, and William W. Zhang
- Subjects
High Energy Astrophysical Phenomena (astro-ph.HE) ,Fabrication ,Materials science ,Spectrometer ,business.industry ,FOS: Physical sciences ,Physics::Optics ,Astronomy and Astrophysics ,Grating ,Diffraction efficiency ,Ray ,Optics ,Space and Planetary Science ,Reflection (physics) ,Astrophysics - Instrumentation and Methods for Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena ,business ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,Lithography ,Microfabrication - Abstract
Future NASA X-ray spectroscopy missions will require high throughput, high resolution grating spectrometers. Off-plane reflection gratings are capable of meeting the performance requirements needed to realize the scientific goals of these missions. We have identified a novel grating fabrication method that utilizes common lithographic and microfabrication techniques to produce the high fidelity groove profile necessary to achieve this performance. Application of this process has produced an initial pre-master that exhibits a radial (variable line spacing along the groove dimension), high density (>6000 grooves/mm), laminar profile. This pre-master has been tested for diffraction efficiency at the BESSY II synchrotron light facility and diffracts up to 55% of incident light into usable spectral orders. Furthermore, tests of spectral resolving power show that these gratings are capable of obtaining resolutions well above 1300 ($\lambda/\Delta\lambda$) with limitations due to the test apparatus, not the gratings. Obtaining these results has provided confidence that this fabrication process is capable of producing off-plane reflection gratings for the next generation of X-ray observatories., Comment: 17 pages, 10 figures, Submitted to Experimetal Astronomy
- Published
- 2013
23. The HEXITEC hard x-ray pixelated CdTe imager for fast solar observations
- Author
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Steven Christe, W. H. Baumgartner, Albert Y. Shih, Colleen A. Wilson-Hodge, Kyle Gregory, Matthew D. Wilson, Jessica A. Gaskin, Paul Seller, Daniel F. Ryan, and Andrew Inglis
- Subjects
Physics ,Point spread function ,Solar flare ,010308 nuclear & particles physics ,business.industry ,Astrophysics::High Energy Astrophysical Phenomena ,Detector ,X-ray detector ,X-ray optics ,Astronomy ,01 natural sciences ,Cadmium telluride photovoltaics ,Heliophysics ,Optics ,0103 physical sciences ,business ,010303 astronomy & astrophysics ,Image resolution - Abstract
There is an increasing demand in solar and astrophysics for high resolution X-ray spectroscopic imaging. Such observations would present ground breaking opportunities to study the poorly understood high energy processes in our solar system and beyond, such as solar flares, X-ray binaries, and active galactic nuclei. However, such observations require a new breed of solid state detectors sensitive to high energy X-rays with fine independent pixels to sub-sample the point spread function (PSF) of the X-ray optics. For solar observations in particular, they must also be capable of handling very high count rates as photon fluxes from solar flares often cause pile up and saturation in present generation detectors. The Rutherford Appleton Laboratory (RAL) has recently developed a new cadmium telluride (CdTe) detector system, called HEXITEC (High Energy X-ray Imaging Technology). It is an 80 x 80 array of 250 micron independent pixels sensitive in the 2-200 keV band and capable of a high full frame read out rate of 10 kHz. HEXITEC provides the smallest independently read out CdTe pixels currently available, and are well matched to the few arcsecond PSF produced by current and next generation hard X-ray focusing optics. NASA's Goddard and Marshall Space Flight Centers are collaborating with RAL to develop these detectors for use on future space borne hard X-ray focusing telescopes. We show the latest results on HEXITEC's imaging capability, energy resolution, high read out rate, and reveal it to be ideal for such future instruments.
- Published
- 2016
24. The X-Ray Surveyor mission concept study: forging the path to NASA astrophysics 2020 decadal survey prioritization
- Author
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Feryal Özel, Alexey Vikhlinin, and Jessica A. Gaskin
- Subjects
Physics ,Prioritization ,Vision ,X-ray astronomy ,COSMIC cancer database ,business.industry ,media_common.quotation_subject ,Astrophysics ,Surveyor ,01 natural sciences ,Universe ,010309 optics ,Observatory ,0103 physical sciences ,business ,010303 astronomy & astrophysics ,PATH (variable) ,media_common - Abstract
The X-Ray Surveyor mission concept is unique among those being studied for prioritization in the NASA Astrophysics 2020 Decadal Survey. The X-Ray Surveyor mission will explore the high-energy Universe; providing essential and complimentary observations to the Astronomy Community. The NASA Astrophysics Roadmap (Enduring Quests, Daring Visions) describes the need for an X-Ray Observatory that is capable of addressing topics such as the origin and growth of the first supermassive black holes, galaxy evolution and growth of the cosmic structure, and the origin and evolution of the stars that make up our Universe. To address these scientifically compelling topics and more, an Observatory that exhibits leaps in capability over that of previous X-Ray Observatories in needed. This paper describes the current status of the X-Ray Surveyor Mission Concept Study and the path forward, which includes scientific investigations, technology development, and community participation.
- Published
- 2016
25. Critical-angle x-ray transmission grating spectrometer with extended bandpass and resolving power > 10,000
- Author
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Ralf K. Heilmann, Alexander R. Bruccoleri, Stephen L. O'Dell, Mark L. Schattenburg, Jessica A. Gaskin, Ritwik Bhatia, and Jeffery J. Kolodziejczak
- Subjects
Diffraction ,Total internal reflection ,Materials science ,Spectrometer ,business.industry ,Stray light ,Physics::Optics ,X-ray optics ,FOS: Physical sciences ,02 engineering and technology ,Grating ,021001 nanoscience & nanotechnology ,Diffraction efficiency ,01 natural sciences ,010309 optics ,Optics ,0103 physical sciences ,Astrophysics - Instrumentation and Methods for Astrophysics ,0210 nano-technology ,business ,Diffraction grating ,Instrumentation and Methods for Astrophysics (astro-ph.IM) - Abstract
Several high priority subjects in astrophysics can be addressed by a state-of-the-art soft x-ray grating spectrometer (XGS). An Explorer-scale, large-area (> 1,000 cm2), high resolving power (R > 3,000) XGS is highly feasible based on Critical-Angle Transmission (CAT) gratings, even for telescopes with angular resolution of 5-10 arcsec. Significantly higher performance can be provided by a CAT XGS on an X-ray-Surveyor-type mission. CAT gratings combine the advantages of blazed reflection gratings (high efficiency, use of higher diffraction orders) with those of transmission gratings (low mass, relaxed alignment and temperature requirements, transparent at high energies) with minimal mission resource demands. They are high-efficiency blazed transmission gratings that consist of freestanding, ultra-high aspect-ratio grating bars made from SOI wafers using anisotropic dry and wet etch techniques. Blazing is achieved through reflection off grating bar sidewalls. Silicon is well matched to the soft x-ray band, and existing silicon CAT gratings exceed 30% absolute diffraction efficiency, with clear paths for improvement. CAT gratings coated with heavier elements allow extension of the CAT grating principle to higher energies and larger angles, enabling higher resolving power at shorter wavelengths. We show x-ray data from CAT gratings coated with platinum using atomic layer deposition, and demonstrate blazing to higher energies and much larger blaze angles than possible with silicon. We measure resolving power of a CAT XGS consisting of a Wolter-I focusing mirror pair from GSFC and CAT gratings, performed at the MSFC SLF. Measurement of the Al Ka doublet in 18th order shows resolving power > 10,000, based on preliminary analysis. This demonstrates that currently fabricated CAT gratings are compatible with the most advanced XGS designs for future soft x-ray spectroscopy missions., submitted to Proc. SPIE 9905
- Published
- 2016
- Full Text
- View/download PDF
26. Toward large-area sub-arcsecond x-ray telescopes II
- Author
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Stephen L. O'Dell, Ryan Allured, Andrew O. Ames, Michael P. Biskach, David M. Broadway, Ricardo J. Bruni, David N. Burrows, Jian Cao, Brandon D. Chalifoux, Kai-Wing Chan, Yip-Wah Chung, Vincenzo Cotroneo, Ronald F. Elsner, Jessica A. Gaskin, Mikhail V. Gubarev, Ralf K. Heilmann, Edward Hertz, Thomas N. Jackson, Kiranmayee Kilaru, Jeffrey J. Kolodziejczak, Ryan S. McClelland, Brian D. Ramsey, Paul B. Reid, Raul E. Riveros, Jacqueline M. Roche, Suzanne E. Romaine, Timo T. Saha, Mark L. Schattenburg, Daniel A. Schwartz, Eric D. Schwartz, Peter M. Solly, Susan Trolier-McKinstry, Melville P. Ulmer, Alexey Vikhlinin, Margeaux L. Wallace, Xiaoli Wang, David L. Windt, Youwei Yao, Shi Ye, William W. Zhang, Heng Zuo, and USA
- Subjects
ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION - Abstract
In order to advance significantly scientific objectives, future x-ray astronomy missions will likely call for x-ray telescopes with large aperture areas (≍ 3 m2) and fine angular resolution (≍ 12). Achieving such performance is programmatically and technologically challenging due to the mass and envelope constraints of space-borne telescopes and to the need for densely nested grazing-incidence optics. Such an x-ray telescope will require precision fabrication, alignment, mounting, and assembly of large areas (≍ 600 m2) of lightweight (≍ 2 kg/m2 areal density) high-quality mirrors, at an acceptable cost (≍ 1 M$/m2 of mirror surface area). This paper reviews relevant programmatic and technological issues, as well as possible approaches for addressing these issues-including direct fabrication of monocrystalline silicon mirrors, active (in-space adjustable) figure correction of replicated mirrors, static post-fabrication correction using ion implantation, differential erosion or deposition, and coating-stress manipulation of thin substrates....
- Published
- 2016
27. Arrays of silicon drift detectors for an extraterrestrial X-ray spectrometer
- Author
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D. Peter Siddons, Gianluigi De Geronimo, Pavel Rehak, Emerson Vernon, Jessica A. Gaskin, Wei Chen, Zheng Li, D. Pinelli, Brian D. Ramsey, Gabriella Carini, and Jack Fried
- Subjects
Physics ,Nuclear and High Energy Physics ,Silicon ,Spectrometer ,Physics::Instrumentation and Detectors ,business.industry ,Detector ,Voltage divider ,chemistry.chemical_element ,Capacitance ,Particle detector ,Semiconductor detector ,Optics ,chemistry ,Electric current ,business ,Instrumentation - Abstract
Arrays of Silicon Drift Detectors (SDD) were designed, produced and tested. These arrays are the central part of an X-Ray Spectrometer (XRS) for measuring the abundances of light surface elements (C–Fe) fluoresced by ambient radiation on the investigated celestial object. The basic building element (or cell) of the arrays consists of a single hexagonal SDD. Signal electrons drift toward the center of the hexagon where a very low capacitance anode is located. The hexagonal shape of an individual SDD allows for a continuous covering of large detection areas of various shapes. To match the number of SDD cells with the external Application Specific Integrated Circuit (ASIC), two arrays, one with 16 and another with 64 cells were developed. One side of SDDs, called the window side, is a continuous thin rectifying junction through which the X-ray radiation enters the detector. The opposite side, called the device side contains electron collecting anodes as well as all other electrodes needed to generate the drift field and to sink leakage current produced on Si–SiO 2 interface. On both sides of the detector array there is a system of guard rings, which smoothly adjusts the voltage of the boundary cells to the ground potential of the silicon outside the sensitive volume. The drift voltage inside the detector is generated by an implanted rectifying contact, which forms a hexagonal spiral. This spiral produces the main valley where signal electrons drift as well as the voltage divider to produce the drift field. System performance is shown by a spectrum of Mn X-rays produced by the decay of 55 Fe.
- Published
- 2010
28. Digital optical correlator x-ray telescope alignment monitoring system
- Author
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Tomasz Lis, Jessica A. Gaskin, Don A. Gregory, and John Jasper
- Subjects
Physics ,Scintillation ,Photon ,business.industry ,Payload ,Optical engineering ,Astrophysics::Instrumentation and Methods for Astrophysics ,General Engineering ,X-ray telescope ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Tracking (particle physics) ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,law.invention ,010309 optics ,Telescope ,Optics ,law ,0103 physical sciences ,Optical correlator ,Astrophysics::Earth and Planetary Astrophysics ,0210 nano-technology ,business - Abstract
The High-Energy Replicated Optics to Explore the Sun (HEROES) program is a balloon-borne x-ray telescope mission to observe hard x-rays (∼20 to 70 keV) from the sun and multiple astrophysical targets. The payload consists of eight mirror modules with a total of 114 optics that are mounted on a 6-m-long optical bench. Each mirror module is complemented by a high-pressure xenon gas scintillation proportional counter. Attached to the payload is a camera that acquires star fields and then matches the acquired field to star maps to determine the pointing of the optical bench. Slight misalignments between the star camera, the optical bench, and the telescope elements attached to the optical bench may occur during flight due to mechanical shifts, thermal gradients, and gravitational effects. These misalignments can result in diminished imaging and reduced photon collection efficiency. To monitor these misalignments during flight, a supplementary Bench Alignment Monitoring System (BAMS) was added to the payload. BAMS hardware comprises two cameras mounted directly to the optical bench and rings of light-emitting diodes (LEDs) mounted onto the telescope components. The LEDs in these rings are mounted in a predefined, asymmetric pattern, and their positions are tracked using an optical/digital correlator. The BAMS analysis software is a digital adaption of an optical joint transform correlator. The aim is to enhance the observational proficiency of HEROES while providing insight into the magnitude of mechanically and thermally induced misalignments during flight. Results from a preflight test of the system are reported.
- Published
- 2018
29. Performance of a Thin-Window Silicon Drift Detector X-Ray Fluorescence Spectrometer
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Pavel Rehak, Jessica A. Gaskin, Zheng Li, Gabriella Carini, Jeffrey W. Keister, Brian D. Ramsey, Wei Chen, G. De Geronimo, and D. P. Siddons
- Subjects
Physics ,Nuclear and High Energy Physics ,Spectrometer ,Pixel ,Silicon drift detector ,Physics::Instrumentation and Detectors ,business.industry ,Detector ,Biasing ,Anode ,Optics ,Nuclear Energy and Engineering ,Electric potential ,Electrical and Electronic Engineering ,business ,Voltage - Abstract
Several sets of hexagonal Silicon Drift Detector (SDD) arrays were produced by Brookhaven National Laboratory (BNL) and by the commercial vendor, KETEK. These detector arrays were tested at BNL. Each array consists of 14 independent SDD detectors (pixels) and two additional test pixels located at two corners of the array. The side of the detector upon which the X-ray radiation is incident (window side) has a thin junction covering the entire active area. The opposite side (device side) contains a drift-field electrode structure in the form of a hexagonal spiral and an electron collecting anode. There are four guard rings surrounding the 14-pixel array area on each side of the detector. Within each array, seven pixels have aluminum field plates - interrupted spirals that stabilize the electric potential under the Si- SiO2 interface, while the other seven do not. Three bias voltages are applied to control the drift field in the silicon volume; one is applied to a rectifying contact surrounding the central anode (one for each pixel), one is applied to the detector entrance window (common to the full array), and a third bias is applied to a contact on the outer portion of the spiral, common to all pixels in the array. Some arrays were recently tested in NSLS beam line U3C at BNL. For this work, we installed the complete assemblies in the vacuum and cooled them to -27degC. During this beam run, we collected spectra for energies ranging between 350 and 900 eV in several pixels, some with field plates and others without. The detailed testing results of several arrays are reported here.
- Published
- 2009
30. Progress in differential deposition for improving the figures of full-shell astronomical grazing incidence x-ray optics
- Author
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Tomasz Lis, Carolyn Atkins, Stephen L. O'Dell, Jeffery K. Kolodziejczak, Kiranmayee Kilaru, Mikhail V. Gubarev, Jessica A. Gaskin, Brian D. Ramsey, and David M. Broadway
- Subjects
X-ray astronomy ,Materials science ,business.industry ,X-ray optics ,Sputter deposition ,engineering.material ,Metrology ,Optics ,Coating ,engineering ,Deposition (phase transition) ,Angular resolution ,business ,Image resolution - Abstract
One of the developments at MSFC that is underway to meet the demand of high-resolution X-ray optics for future X-ray astronomy missions is the ‘differential deposition’ technique. This process corrects the axial figure profile of optics by selectively depositing material onto the mirror’s reflective surface. The process relies on accurate metrology achieved using a long trace profiler whose slope resolution is better than 1μrad. From these metrology data an error map is generated that shows the profile of material to be deposited to correct the optic’s figure. A computer-controlled, deposition system then applies this corrective coating. Simulations show that a substantial improvement in angular resolution is possible with this approach after multiple correction ‘cycles’. To assess this, custom coating systems have been developed and corrections of full-shell optics are underway. To date, a factor of < 2 improvement in the imaging quality of the optics has been demonstrated in x-ray tests after a single stage of correction.
- Published
- 2015
31. TheX-ray SurveyorMission: a concept study
- Author
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Zachary Prieskorn, Martin C. Weisskopf, Chryssa Kouveliotou, Robert Petre, Simon R. Bandler, Andrew Schnell, Abraham D. Falcone, Sebastian Heinz, Jessica A. Gaskin, David N. Burrows, Ralf K. Heilmann, Marshall W. Bautz, Harvey Tananbaum, Daniel A. Schwartz, Alexey Vikhlinin, Brian D. Ramsey, Paul B. Reid, Caroline A. Kilbourne, Randall L. McEntaffer, Fiona A. Harrison, Andrew Ptak, Leisa K. Townsley, Stephen L. O'Dell, Andrey V. Kravtsov, Ralph P. Kraft, Priyamvada Natarajan, Randall C. Hopkins, and Siegmund, Oswald H. W.
- Subjects
Physics ,X-ray astronomy ,Active galactic nucleus ,Galactic astronomy ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astronomy ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Galaxy ,Galaxy groups and clusters ,Observatory ,Galaxy group ,Astrophysics::Galaxy Astrophysics ,Galaxy cluster - Abstract
NASA's Chandra X-ray Observatory continues to provide an unparalleled means for exploring the high-energy universe. With its half-arcsecond angular resolution, Chandra studies have deepened our understanding of galaxy clusters, active galactic nuclei, galaxies, supernova remnants, neutron stars, black holes, and solar system objects. As we look beyond Chandra, it is clear that comparable or even better angular resolution with greatly increased photon throughput is essential to address ever more demanding science questions—such as the formation and growth of black hole seeds at very high redshifts; the emergence of the first galaxy groups; and details of feedback over a large range of scales from galaxies to galaxy clusters. Recently, we initiated a concept study for such a mission, dubbed X-ray Surveyor. The X-ray Surveyor strawman payload is comprised of a high-resolution mirror assembly and an instrument set, which may include an X-ray microcalorimeter, a high-definition imager, and a dispersive grating spectrometer and its readout. The mirror assembly will consist of highly nested, thin, grazing-incidence mirrors, for which a number of technical approaches are currently under development—including adjustable X-ray optics, differential deposition, and new polishing techniques applied to a variety of substrates. This study benefits from previous studies of large missions carried out over the past two decades and, in most areas, points to mission requirements no more stringent than those of Chandra.
- Published
- 2015
32. CdTe focal plane detector for hard x-ray focusing optics
- Author
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Paul Seller, Colleen A. Wilson-Hodge, Kyle Gregory, Matthew D. Wilson, Andreas Schneider, Steven Christe, Jessica A. Gaskin, Matthew C. Veale, Andrew Inglis, Albert Y. Shih, and Marco Panessa
- Subjects
Physics ,Physics::Instrumentation and Detectors ,business.industry ,Detector ,Astrophysics::Instrumentation and Methods for Astrophysics ,X-ray detector ,X-ray optics ,X-ray telescope ,Solar physics ,law.invention ,Telescope ,Cardinal point ,Optics ,law ,Focal length ,business - Abstract
The demand for higher resolution x-ray optics (a few arcseconds or better) in the areas of astrophysics and solar science has, in turn, driven the development of complementary detectors. These detectors should have fine pixels, necessary to appropriately oversample the optics at a given focal length, and an energy response also matched to that of the optics. Rutherford Appleton Laboratory have developed a 3-side buttable, 20 millimeter x 20 millimeter CdTe-based detector with 250 micrometer square pixels (80 x 80 pixels) which achieves 1 kiloelectronvolt FWHM (Full-Width Half-Maximum) @ 60 kiloelectronvolts and gives full spectroscopy between 5 kiloelectronvolts and 200 kiloelectronvolts. An added advantage of these detectors is that they have a full-frame readout rate of 10 kilohertz. Working with NASA Goddard Space Flight Center and Marshall Space Flight Center, 4 of these 1 millimeter-thick CdTe detectors are tiled into a 2 x 2 array for use at the focal plane of a balloon-borne hard-x-ray telescope, and a similar configuration could be suitable for astrophysics and solar space-based missions. This effort encompasses the fabrication and testing of flight-suitable front-end electronics and calibration of the assembled detector arrays. We explain the operation of the pixelated ASIC readout and measurements, front-end electronics development, preliminary X-ray imaging and spectral performance, and plans for full calibration of the detector assemblies. Work done in conjunction with the NASA Centers is funded through the NASA Science Mission Directorate Astrophysics Research and Analysis Program.
- Published
- 2015
33. X-ray optics at NASA Marshall Space Flight Center
- Author
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Stephen L. O'Dell, Jeffery J. Kolodziejczak, Carolyn Atkins, Jessica A. Gaskin, Kiranmayee Kilaru, Allyn F. Tennant, Brian D. Ramsey, V. E. Zavlin, Ronald F. Elsner, David M. Broadway, Martin C. Weisskopf, Jacqueline M. Roche, Douglas A. Swartz, and Mikhail V. Gubarev
- Subjects
Engineering ,business.product_category ,Fabrication ,business.industry ,X-ray optics ,Mature technology ,X-ray telescope ,law.invention ,Telescope ,Optics ,Rocket ,law ,Satellite ,Angular resolution ,business - Abstract
NASA's Marshall Space Flight Center (MSFC) engages in research, development, design, fabrication, coating, assembly, and testing of grazing-incidence optics (primarily) for x-ray telescope systems. Over the past two decades, MSFC has refined processes for electroformed-nickel replication of grazing-incidence optics, in order to produce high-strength, thin-walled, full-cylinder x-ray mirrors. In recent years, MSFC has used this technology to fabricate numerous x-ray mirror assemblies for several flight (balloon, rocket, and satellite) programs. Additionally, MSFC has demonstrated the suitability of this technology for ground-based laboratory applications-namely, x-ray microscopes and cold-neutron microscopes and concentrators. This mature technology enables the production, at moderately low cost, of reasonably lightweight x-ray telescopes with good (15-30 arcsecond) angular resolution. However, achieving arcsecond imaging for a lightweight x-ray telescope likely requires development of other technologies. Accordingly, MSFC is conducting a multi-faceted research program toward enabling cost-effective production of lightweight high-resolution x-ray mirror assemblies. Relevant research topics currently under investigation include differential deposition for post-fabrication figure correction, in-situ monitoring and control of coating stress, and direct fabrication of thin-walled full-cylinder grazing-incidence mirrors.
- Published
- 2015
34. SuperHERO: Design of a new hard-X-ray focusing telescope
- Author
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Brian D. Ramsey, Paul Seller, Steven Christe, Allyn F. Tennant, Ronald F. Elsner, Matthew D. Wilson, Albert Y. Shih, Kiranmayee Kilaru, Colleen A. Wilson-Hodge, David Stuchlik, Jessica A. Gaskin, Bruce Weddendorf, and Douglas A. Swartz
- Subjects
Physics ,High energy ,X-ray astronomy ,business.industry ,Detector ,X-ray detector ,X-ray optics ,Astronomy ,X-ray telescope ,law.invention ,Telescope ,Optics ,law ,Angular resolution ,business - Abstract
SuperHERO is a hard x-ray (20–75 keV) balloon-borne telescope, currently in its proposal phase, that will utilize high angular-resolution grazing-incidence optics, coupled to novel CdTe multi-pixel, fine-pitch (250 µm) detectors. The high-resolution electroformed-nickel, grazing-incidence optics were developed at MSFC, and the detectors were developed at the Rutherford Appleton Laboratory in the UK, and are being readied for flight at GSFC. SuperHERO will use two active pointing systems; one for carrying out astronomical observations and another for solar observations during the same flight. The telescope will reside on a light-weight, carbon-composite structure that will integrate the Wallops Arc Second Pointer into its frame, for arcsecond or better pointing. This configuration will allow for Long Duration Balloon flights that can last up to 4 weeks. This next generation design, which is based on the High Energy Replicated Optics (HERO) and HERO to Explore the Sun (HEROES) payloads, will be discussed, with emphasis on the core telescope components.
- Published
- 2015
35. Beyond Chandra - the X-ray Surveyor
- Author
-
Alexey Vikhlinin, Martin C. Weisskopf, Harvey Tananbaum, and Jessica A. Gaskin
- Subjects
Physics ,X-ray astronomy ,Active galactic nucleus ,Galactic astronomy ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astronomy ,FOS: Physical sciences ,X-ray telescope ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Galaxy ,law.invention ,Telescope ,Observatory ,law ,Astrophysics - Instrumentation and Methods for Astrophysics ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,Galaxy cluster - Abstract
Over the past 16 years, NASA's Chandra X-ray Observatory has provided an unparalleled means for exploring the universe with its half-arcsecond angular resolution. Chandra studies have deepened our understanding of galaxy clusters, active galactic nuclei, galaxies, supernova remnants, planets, and solar system objects addressing almost all areas of current interest in astronomy and astrophysics. As we look beyond Chandra, it is clear that comparable or even better angular resolution with greatly increased photon throughput is essential to address even more demanding science questions, such as the formation and subsequent growth of black hole seeds at very high redshift; the emergence of the first galaxy groups; and details of feedback over a large range of scales from galaxies to galaxy clusters. Recently, NASA Marshall Space Flight Center, together with the Smithsonian Astrophysical Observatory, has initiated a concept study for such a mission named the X-ray Surveyor. This study starts with a baseline payload consisting of a high resolution X-ray telescope and an instrument set which may include an X-ray calorimeter, a wide-field imager and a dispersive grating spectrometer and readout. The telescope would consist of highly nested thin shells, for which a number of technical approaches are currently under development, including adjustable X-ray optics, differential deposition, and modern polishing techniques applied to a variety of substrates. In many areas, the mission requirements would be no more stringent than those of Chandra, and the study takes advantage of similar studies for other large area missions carried out over the past two decades. Initial assessments indicate that such an X-ray mission is scientifically compelling, technically feasible, and worthy of a high rioritization by the next American National Academy of Sciences Decadal Survey for Astronomy and Astrophysics., Comment: 6 pages, 6 figures, paper 9510-01 presented at SPIE Europe, Prague, April 2015
- Published
- 2015
- Full Text
- View/download PDF
36. Calibration of the High Energy Replicated Optics to Explore the Sun (HEROES) Hard X-ray Telescope
- Author
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Brian D. Ramsey, Jeff Kolodziejczak, Allyn F. Tennant, Kiranmayee Kilaru, Colleen A. Wilson-Hodge, Albert Y. Shih, R. F. Elsner, Steven Christe, Jessica A. Gaskin, and D. Swartz
- Subjects
Physics ,business.industry ,Astrophysics::High Energy Astrophysical Phenomena ,Continuum (design consultancy) ,Detector ,Astrophysics::Instrumentation and Methods for Astrophysics ,X-ray optics ,Astronomy ,Astronomy and Astrophysics ,X-ray telescope ,Astrophysics ,law.invention ,Telescope ,Crab Nebula ,Optics ,law ,Calibration ,Ray tracing (graphics) ,business ,Instrumentation - Abstract
On 2013 September 21–22, the High Energy Replicated Optics to Explore the Sun (HEROES) hard X-ray telescope flew as a balloon payload from Ft. Sumner, NM. HEROES observed the Sun, the black hole binary GRS 1915+105, and the Crab Nebula during its 27 h flight. In this paper, we describe laboratory calibration measurements of the HEROES detectors using line and continuum sources and applications of these measurements to define channel to energy (gain) corrections for observed events and to define detector response matrices. We characterize the HEROES X-ray grazing incidence optics using measurements taken in the Stray Light Facility (SLF) in Huntsville, AL, and using ray traces. We describe the application of our calibration measurements to in-flight observations of the Crab Nebula.
- Published
- 2014
37. Development of a high spatial resolution detector for at-wavelength metrology of x-ray optics
- Author
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Julia Vogel, Stuart Miller, Harish B. Bhandari, Vivek V. Nagarkar, Jessica A. Gaskin, Michael J. Pivovaroff, Bipin Singh, and Brian D. Ramsey
- Subjects
Point spread function ,Physics ,business.industry ,Stray light ,Astrophysics::High Energy Astrophysical Phenomena ,Detector ,Astrophysics::Instrumentation and Methods for Astrophysics ,X-ray optics ,Photon counting ,Metrology ,law.invention ,Telescope ,Optics ,law ,Optoelectronics ,Photonics ,business - Abstract
Recent advancements in the field of x-ray astronomy have relied significantly on innovations in grazing-incidence x-ray optics technology, especially for the hard x-ray range for energies above 10 keV. The behavior of these x-ray telescopes for current and planned astrophysical and solar imaging missions needs to be well understood, and fully characterizing the optics includes measurements of the point spread function and effective area for flight optics as a function of energy and off-axis position as well as understanding the scattering and reflectivity properties of substrate coatings. This requires unique detectors with large areas, very high spatial resolution, high sensitivity, photon counting capability and energy discrimination. We report on the development of a detector that is well suited to meet these requirements. The key piece of the instrument is a high spatial-resolution, electron-multiplying charge-coupled device. The detector is back-thinned and optically bonded via a fiberoptic taper to a purpose-fabricated high resolution, high brightness CsI:Tl scintillator with a microcolumnar structure. A prototype version of this camera was used to calibrate the x-ray focusing optics for the Nuclear Spectroscopic Telescope Array (NuSTAR) mission successfully operating in space since its launch in June 2012. Here we present our recent work on the design of the EMCCD detector and scintillators, fabrication, assembly and testing of the full detector system as well as our software development efforts for single photon detection and energy discrimination. Also included are first results from our recent measurement campaign at the x-ray stray light calibration facility of NASA's Marshall Space Flight Center.
- Published
- 2014
38. Charge sharing and charge loss in a cadmium–zinc–telluride fine-pixel detector array
- Author
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Brian D. Ramsey, Jessica A. Gaskin, and D.P. Sharma
- Subjects
Physics ,Nuclear and High Energy Physics ,Pixel ,Physics::Instrumentation and Detectors ,business.industry ,Detector ,Charge density ,Particle detector ,Semiconductor detector ,Charge sharing ,Cadmium zinc telluride ,chemistry.chemical_compound ,Optics ,chemistry ,business ,Instrumentation ,Image resolution - Abstract
Because of its high atomic number, room temperature operation, low noise, and high spatial resolution a Cadmium-Zinc-Telluride (CZT) multi-pixel detector is ideal for hard x-ray astrophysical observation. As part of on-going research at MSFC (Marshall Space Flight Center) to develop multi-pixel CdZnTe detectors for this purpose, we have measured charge sharing and charge loss for a 4x4 (750micron pitch), lmm thick pixel array and modeled these results using a Monte-Carlo simulation. This model was then used to predict the amount of charge sharing for a much finer pixel array (with a 300micron pitch). Future work will enable us to compare the simulated results for the finer array to measured values.
- Published
- 2003
39. SuperHERO: the next generation hard x-ray HEROES telescope
- Author
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Allyn F. Tennant, Ronald F. Elsner, Brian D. Ramsey, Albert Y. Shih, Paul Seller, Jessica A. Gaskin, Kiranmayee Kilaru, Matthew Wilson, Bruce Weddendorf, Colleen A. Wilson-Hodge, David Stuchlik, Douglas A. Swartz, and Steven Christe
- Subjects
Telescope ,Physics ,X-ray astronomy ,Heliophysics ,law ,Payload ,Launched ,Astronomy ,X-ray optics ,X-ray telescope ,Solar physics ,law.invention - Abstract
SuperHERO is a new high-sensitivity Long Duration Balloon (LDB)-capable, hard-x-ray (20-75 keV) telescope for making novel astrophysics and heliophysics observations. The proposed SuperHERO payload will be developed jointly by the Astrophysics Office at NASA Marshall Space Flight Center, the Solar Physics Laboratory and Wallops Flight Facility at NASA Goddard Space Flight Center. SuperHERO is a follow-on payload to the High Energy Replicated Optics to Explore the Sun (HEROES) balloon-borne telescope that recently launched from Fort Sumner, NM in September of 2013. The HEROES core instrument is a hard x-ray telescope consisting of x-ray 109 optics configured into 8 modules. Each module is aligned to a matching gas-filled detector at a focal length of 6 m. SuperHERO will make significant improvements to the HEROES payload, including: new solid-state multi-pixel CdTe detectors, additional optics, the Wallops Arc-Second Pointer, alignment monitoring systems and lighter gondola.
- Published
- 2014
40. Developments in the EM-CCD camera for OGRE
- Author
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Andrew D. Holland, Jeff Kolodziejczak, David Colebrook, Ted Schultz, James H. Tutt, Drew M. Miles, A M Evagora, Webster Cash, Steve O'Dell, Neil J. Murray, Jessica A. Gaskin, Thomas Rogers, Randall L. McEntaffer, Karen Holland, William W. Zhang, and Casey T. DeRoo
- Subjects
Physics ,business.product_category ,Ccd camera ,Spectrometer ,Payload ,business.industry ,Detector ,Emphasis (telecommunications) ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,Grating ,Space exploration ,Optics ,Rocket ,business - Abstract
The Off-plane Grating Rocket Experiment (OGRE) is a sub-orbital rocket payload designed to advance the development of several emerging technologies for use on space missions. The payload consists of a high resolution soft X-ray spectrometer based around an optic made from precision cut and ground, single crystal silicon mirrors, a module of off-plane gratings and a camera array based around Electron Multiplying CCD (EM-CCD) technology. This paper gives an overview of OGRE with emphasis on the detector array; specifically this paper will address the reasons that EM-CCDs are the detector of choice and the advantages and disadvantages that this technology offers.
- Published
- 2014
41. A Solar Aspect System for the HEROES mission
- Author
-
Steven Christe, Brian O'Connor, Alexander Sobey, Marcello Rodriguez, Alexander Cramer, Albert Y. Shih, Jessica A. Gaskin, Kyle Gregory, and Melissa Edgerton
- Subjects
Optics ,business.industry ,Computer science ,Payload ,Horizon ,Synthetic aperture sonar ,Prism ,business ,High-altitude balloon ,Image resolution - Abstract
A new Solar Aspect System (SAS) has been developed to provide the ability to observe the Sun on an existing balloon payload HERO (short for High Energy Replicated Optics). Developed under the HEROES program (High Energy Replicated Optics to Explore the Sun), the SAS aspect system provides solar pointing knowledge in pitch, yaw, and roll. The required precision of these measurements must be better than the HEROES X-ray resolution of ∼20 arcsec Full Width at Half Maximum (FWHM) so as to not degrade the image resolution. The SAS consists of two separate systems: the Pitch-Yaw Aspect System (PYAS) and the Roll Aspect System (RAS). The PYAS functions by projecting an image of the Sun onto a screen with precision fiducials. A CCD camera takes an image of these fiducials, and an automated algorithm determines the location of the Sun as well as the location of the fiducials. The spacing between fiducials is unique and allows each to be identified so that the location of the Sun on the screen can be precisely determined. The RAS functions by imaging the Earth's horizon in opposite directions using a silvered prism imaged by a CCD camera. The design and first results of the performance of these systems during the HEROES flight which occurred in September 2013 are presented here.
- Published
- 2014
42. High Energy Replicated Optics to Explore the Sun balloon-borne telescope: Astrophysical pointing
- Author
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Steven Christe, Jeff Apple, Albert Y. Shih, Colleen A. Wilson-Hodge, Jessica A. Gaskin, Allyn F. Tennant, Brian D. Ramsey, Kurt Dietz, and Douglas A. Swartz
- Subjects
Physics ,High energy ,business.industry ,Payload ,Data reconstruction ,Launched ,Astronomy ,Monitoring system ,X-ray telescope ,law.invention ,Telescope ,Optics ,law ,Balloon-borne telescope ,business - Abstract
On September 21st, 2013, the High Energy Replicated Optics to Explore the Sun, or HEROES, balloon-borne x-ray telescope launched from the Columbia Scientific Balloon Facility's site in Ft. Sumner, NM. The flight lasted for ∼27 hours and the observational targets included the Sun and astrophysical sources GRS 1915+105 and the Crab Nebula. Over the past year, the HEROES team upgraded the existing High Energy Replicated Optics (HERO) balloon-borne telescope to make unique scientific measurements of the Sun and astrophysical targets during the same flight. The HEROES Project is a multi-NASA Center effort with team members at both Marshall Space Flight Center (MSFC) and Goddard Space Flight Center (GSFC), and is led by Co-PIs (one at each Center). The HEROES payload consists of the hard X-ray telescope HERO, developed at MSFC, combined with several new systems. To allow the HEROES telescope to make observations of the Sun, a new solar aspect system was added to supplement the existing star camera for fine pointing during both the day and night. A mechanical shutter was added to the star camera to protect it during solar observations and two alignment monitoring systems were added for improved pointing and post-flight data reconstruction. This mission was funded by the NASA HOPE (Hands-On Project Experience) Training Opportunity awarded by the NASA Academy of Program/Project and Engineering Leadership, in partnership with NASA's Science Mission Directorate, Office of the Chief Engineer and Office of the Chief Technologist.
- Published
- 2014
43. The high energy replicated optics to explore the sun mission: a hard x-ray balloon-borne telescope
- Author
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Katherine Stevenson Chavis, Marcello Rodriguez, Alex Sobey, Jessica A. Gaskin, Kyle Gregory, Heather Koehler, Colleen A. Wilson-Hodge, Brian D. Ramsey, Leigh Smith, Amanda C. Jackson, Kurt Dietz, Melissa Edgerton, Steven Christe, Brian O'Connor, Albert Y. Shih, Jeff Apple, and Alex Cramer
- Subjects
Physics ,business.industry ,Payload ,Solar physics ,law.invention ,Telescope ,Upgrade ,Heliophysics ,Optics ,law ,Balloon-borne telescope ,Inclinometer ,Differential GPS ,business - Abstract
Set to fly in the Fall of 2013 from Ft. Sumner, NM, the High Energy Replicated Optics to Explore the Sun (HEROES) mission is a collaborative effort between the NASA Marshall Space Flight Center and the Goddard Space Flight Center to upgrade an existing payload, the High Energy Replicated Optics (HERO) balloon-borne telescope, to make unique scientific measurements of the Sun and astrophysical targets during the same flight. The HEROES science payload consists of 8 mirror modules, housing a total of 109 grazing-incidence optics. These modules are mounted on a carbon-fiber and Aluminum optical bench 6 m from a matching array of high pressure xenon gas scintillation proportional counters, which serve as the focal-plane detectors. The HEROES gondola utilizes a differential GPS system (backed by a magnetometer) for coarse pointing in the azimuth and a shaft angle encoder plus inclinometer provides the coarse elevation. The HEROES payload will incorporate a new solar aspect system to supplement the existing star camera, for fine pointing during both the day and night. The overall payload will be discussed as well as the new solar aspect system. This mission is funded by the NASA HOPE (Hands On Project Experience) Training Opportunity awarded by the NASA Academy of Program/Project and Engineering Leadership, in partnership with NASA's Science Mission Directorate, Office of the Chief Engineer and Office of the Chief Technologist.
- Published
- 2013
44. X-ray optic developments at NASA's MSFC
- Author
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Kiranmayee Kilaru, Carolyn Atkins, Mikhail Gubarev, R. F. Elsner, D. Swartz, Steve O'Dell, B. Ramsey, Jessica A. Gaskin, and Martin C. Weisskopf
- Subjects
Physics ,business.product_category ,business.industry ,Payload ,X-ray optics ,X-ray telescope ,law.invention ,Telescope ,Optics ,Rocket ,Proof of concept ,law ,Electroforming ,Angular resolution ,business - Abstract
NASA's Marshall Space Flight Center (MSFC) has a successful history of fabricating optics for astronomical x-ray telescopes. In recent years optics have been created using electroforming replication for missions such as the balloon payload HERO (High energy replicated optics) and the rocket payload FOXSI (Focusing Optics x-ray Solar Imager). The same replication process is currently being used in the creation seven x-ray mirror modules (one module comprising of 28 nested shells) for the Russian ART-XC (Astronomical Rontgen Telescope) instrument aboard the Spectrum-Roentgen-Gamma mission and for large-diameter mirror shells for the Micro-X rocket payload. In addition to MSFC's optics fabrication, there are also several areas of research and development to create the high resolution light weight optics which are required by future x-ray telescopes. Differential deposition is one technique which aims to improve the angular resolution of lightweight optics through depositing a filler material to smooth out fabrication imperfections. Following on from proof of concept studies, two new purpose built coating chambers are being assembled to apply this deposition technique to astronomical x-ray optics. Furthermore, MSFC aims to broaden its optics fabrication through the recent acquisition of a Zeeko IRP 600 robotic polishing machine. This paper will provide a summary of the current missions and research and development being undertaken at NASA's MSFC.
- Published
- 2013
45. A low-power, radiation-resistant ASIC for SDD-based x-ray spectrometers
- Author
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Jack Fried, Gianluigi De Geronimo, Brian D. Ramsey, Wei Chen, Shaorui Li, Graham C. Smith, D. Pinelli, Zheng Li, Jessica A. Gaskin, and Alessio D'Anadragora
- Subjects
Physics ,Nuclear and High Energy Physics ,Spectrometer ,business.industry ,Electrical engineering ,Ranging ,Radiation ,Differential signaling ,Nuclear Energy and Engineering ,Beamline ,Application-specific integrated circuit ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Radiation hardening ,Radiation resistance - Abstract
We present an Application Specific Integrated Circuit (ASIC) for high resolution X-ray spectrometers (XRS) in radiation harsh environment (such as Jovian system). The ASIC was designed to read out signals from low resistivity pixelated Silicon-Drift-Detectors (SDD) to ensure radiation hardness. The readout is done by wire-bonding the anodes to the inputs of the ASIC. The ASIC dissipates 32 mW and provides 16 channels of low-noise charge amplification, high-order shaping with baseline stabilization, discrimination, pile-up rejection, and peak detection with analog memory. The readout is sparse and based on a custom low-power tri-stable low-voltage differential signaling digital interface. A unit of 64 SDD pixels, read out by four ASICs, covers an area of 12.8 cm2, and dissipates less than 20 mW/cm2. The ASICs were powered on and irradiated using a beam line with 203 MeV protons, to total doses ranging from 0.25 Mrad to 12 Mrad. Performance degradation due to radiation-induced leakage current was observed to peak around 2 Mrad dose. Critical contributors to the degradation were identified through simulation and measurements, and corresponding circuitry was thus modified to address the issues. Measurements on the radiation-resistant design have shown excellent radiation resistance at total doses ranging from 1 to 8 Mrad.
- Published
- 2012
46. Next generation astronomical x-ray optics: high angular resolution, light weight, and low production cost
- Author
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Linette D. Kolos, Jessica A. Gaskin, Kai-Wing Chan, Marton V. Sharpe, James R. Mazzarella, R. S. McClelland, Peter Blake, William D. Jones, Melinda Hong, Timo T. Saha, Steve O'Dell, William W. Zhang, and Michael P. Biskach
- Subjects
Physics ,X-ray astronomy ,business.industry ,X-ray optics ,X-ray telescope ,Term (time) ,law.invention ,Telescope ,Optics ,law ,New product development ,Angular resolution ,business ,Image resolution - Abstract
X-ray astronomy depends on the availability of telescopes with high resolution and large photon collecting areas. Since x-ray observation can only be carried out above the atmosphere, these telescopes must be necessarily lightweight. Compounding the lightweight requirement is that an x-ray telescope consists of many nested concentric shells, which further require that x-ray mirrors must also be geometrically thin to achieve high packing efficiency. This double lightweight and geometrically thin requirement poses significant technical challenges in fabricating the mirrors and in integrating them into mirror assemblies. This paper reports on the approach, strategy and status of our x-ray optics development program whose objective is to meet these technical challenges at modest cost to enable future x-ray missions, including small Explorer missions in the near term, probe class missions in the medium term, and large flagship missions in the long term.
- Published
- 2012
47. Pixellated Cd(Zn)Te high-energy X-ray instrument
- Author
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Matthew C. Veale, Brian D. Ramsey, Steven Bell, Silvia Pani, Matthew D. Wilson, Paul Seller, C. K. Egan, Jessica A. Gaskin, Paul J. Sellin, Robert J. Cernik, Simon D. M. Jacques, James Scuffham, Robert D. Speller, C Christodoulou, and C. Reid
- Subjects
Physics ,Interconnection ,business.industry ,Detector ,X-ray detector ,Cadmium telluride photovoltaics ,Article ,law.invention ,Cadmium zinc telluride ,chemistry.chemical_compound ,Full width at half maximum ,Data acquisition ,chemistry ,law ,Optoelectronics ,business ,Instrumentation ,Mathematical Physics ,Gamma camera - Abstract
We have developed a pixellated high energy X-ray detector instrument to be used in a variety of imaging applications. The instrument consists of either a Cadmium Zinc Telluride or Cadmium Telluride (Cd(Zn)Te) detector bump-bonded to a large area ASIC and packaged with a high performance data acquisition system. The 80 by 80 pixels each of 250 μm by 250 μm give better than 1 keV FWHM energy resolution at 59.5 keV and 1.5 keV FWHM at 141 keV, at the same time providing a high speed imaging performance. This system uses a relatively simple wire-bonded interconnection scheme but this is being upgraded to allow multiple modules to be used with very small dead space. The readout system and the novel interconnect technology is described and how the system is performing in several target applications.
- Published
- 2012
48. Miniature Variable Pressure Scanning Electron Microscope for in-situ imaging & chemical analysis
- Author
-
Allen R. Sampson, Don A. Gregory, Jessica A. Gaskin, and Gregory Jerman
- Subjects
Physics ,Atmosphere ,Atmospheric pressure ,Scanning electron microscope ,Ultra-high vacuum ,Variable pressure ,Atmosphere of Mars ,Mars Exploration Program ,Remote sensing ,Electron gun - Abstract
NASA Marshall Space Flight Center (MSFC) is leading an effort to develop a Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) for in-situ imaging and chemical analysis of uncoated samples. This instrument development will be geared towards operation on Mars and builds on a previous MSFC design of a mini-SEM for the moon (funded through the NASA Planetary Instrument Definition and Development Program). Because Mars has a dramatically different environment than the moon, modifications to the MSFC lunar mini-SEM are necessary. Mainly, the higher atmospheric pressure calls for the use of an electron gun that can operate at High Vacuum, rather than Ultra-High Vacuum. The presence of a CO 2 -rich atmosphere also allows for the incorporation of a variable pressure system that enables the in-situ analysis of nonconductive geological specimens. Preliminary testing of Mars meteorites in a commercial Environmental SEM™ (FEI) confirms the usefulness of low-current/low-accelerating voltage imaging and highlights the advantages of using the Mars atmosphere for environmental imaging. The unique capabilities of the MVP-SEM make it an ideal tool for pursuing key scientific goals of NASA's Flagship Mission Max-C; to perform in-situ science and collect and cache samples in preparation for sample return from Mars.
- Published
- 2012
49. Radiation effects of n-type, low resistivity, spiral silicon drift detector hybrid systems
- Author
-
Jeffrey W. Keister, Gabriella Carini, E. M. Verbitskaya, Wen-Chang Chen, Brian D. Ramsey, Jessica A. Gaskin, Shaorui Li, Graham C. Smith, G. De Geronimo, D. P. Siddons, and Z. Li
- Subjects
Physics ,Spectrometer ,Silicon drift detector ,business.industry ,Detector ,Cyclotron ,Electrical engineering ,Particle accelerator ,law.invention ,Beamline ,law ,Optoelectronics ,business ,Radiation hardening ,Diode - Abstract
We have developed a new thin-window, n-type, low-resistivity, spiral silicon drift detector (SDD) array - to be used as an extraterrestrial X-ray spectrometer (in varying environments) for NASA. To achieve low-energy response, a thin SDD entrance window was produced using a previously developed method. These thin-window devices were also produced on lower resistivity, thinner, n-type, silicon material, effectively ensuring their radiation hardness in anticipation of operation in potentially harsh radiation environments (such as found around the Jupiter system). Using the Indiana University Cyclotron Facility beam line RERS1, we irradiated a set of suitable diodes up to 5 Mrad and the latest iteration of our ASICs up to 12 Mrad. Then we irradiated two hybrid detectors consisting of newly, such-produced in-house (BNL) SDD chips bonded with ASICs with doses of 0.25 Mrad and 1 Mrad. Also we irradiated another hybrid detector consisting of previously produced (by KETEK) on n-type, high-resistivity SDD chip bonded with BNL's ASICs with a dose of 1 Mrad. The measurement results of radiated diodes (up to 5 Mrad), ASICs (up to 12 Mrad) and hybrid detectors (up to 1 Mrad) are presented here.
- Published
- 2011
50. Differential deposition to correct surface figure deviations in astronomical grazing-incidence x-ray optics
- Author
-
Jessica A. Gaskin, Kiranmayee Kilaru, Stephen L. O'Dell, Mikhail V. Gubarev, Brian D. Ramsey, and William W. Zhang
- Subjects
Physics ,Fabrication ,Optics ,Geometrical optics ,business.industry ,Physical vapor deposition ,Near-field optics ,Shell (structure) ,Optoelectronics ,Deposition (phase transition) ,X-ray optics ,business ,Image resolution - Abstract
A coating technique is being developed to correct the surface figure deviations in reflective-grazing-incidence X-ray optics. These optics are typically designed to have precise conic profiles, and any deviation in this profile, as a result of fabrication, results in a degradation of the imaging performance. To correct the mirror profiles, physical vapor deposition has been utilized to selectively deposit a filler material inside the mirror shell. The technique, termed differential deposition, has been implemented as a proof of concept on miniature X-ray optics developed at MSFC for medical-imaging applications. The technique is now being transferred to larger grazing-incidence optics suitable for astronomy and progress to date is reported.
- Published
- 2011
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