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Traditional multi-camera calibration is usually on one side of the calibration board. If there are several cameras distributing on both sides of the calibration board, each camera needs to be calibrated on each side. Thus, the error accumulated from each calibration will have a non-ignorable impact on the results. In this paper, we presents a method that using transparent glass board to replace ordinary calibration board based on Zhang Zhengyou’s calibration method. We also introduce two new parameters (depth and refractive index of glass). Therefore, calibration of several cameras can be completed by one experiment. The calibration of camera in the front of the transparent glass board uses traditional calibration method and LM iterative algorithm to obtain the internal and external camera parameters. The calibration of camera on back side uses the traditional calibration model and the light refraction model, and the results without considering the refraction condition are served as the initial values. Th...

In recent years Electronic Portal Imaging Devices (EPIDs) have become indispensable tools for the patient verification set-up in radiotherapy. While EPIDs are primarily used for the assessment of patient positioning and quality control of the accelerator parameters, they also represent an attractive method for the dose verification. Therefore, for their use in dosimetry, it is necessary to investigate their physical characteristics and perform their calibration. The aim of the present study is the development of a calibration procedure and investigation of the stability and the linearity of the signal of an amorphous silicon detector, the a-Si 1000 for Varian systems. The calibration is carried out on the central axis of the beam in the center of the image. To test the signal stability, the detector is placed in the central axis, at a fixed distance of the source with an open field 10 x 10 cm2 and irradiated at regular time intervals, using the 6MV photon beam. The linearity of the signal with the dose and with the dose rate is investigated by varying the dose between 1 cGy to 900 cGy for each dose rate 100, 200, 300, 400 and 500 UM/min. The EPID is calibrated in terms of absolute dose in two steps, the first one is the image calibration, and the second one is the dose calibration. The image calibration is carried out to correct the raw image involving the measurement of a Dark Field (DF) image acquired with no radiation to measure electronic noise, and a Flood Field (FF) image acquired with a maximum open field to determine pixel sensitivities. The dose calibration is carried out with the 0.6 cm3 TM 30013 Farmer ionization chamber (PTW Freiburg Germany) placed in the water phantom at the depth dmax=1.5 cm. Once calibrate, the dose measured at the center of the detector placed in the center axis of the beam is confronted with the dose measured with the 0.3 cm3 TM 31013 Semiflex ionization chamber (PTW Freiburg Germany) placed in the center of a cylindrical phantom dedicated for the verification of treatment plans in IMRT and VMAT techniques. Five treatment plans are verified. The stability results reveal a deviation about 0.37% after the first 4 minutes of irradiation and about 0.10% after 30 minutes of irradiation. The linearity investigation exhibited a correlation factor that exceeds 0.99 which allows us to conclude that the detector has a good linearity of the signal with the dose and with the dose rate. The comparison between the dose measured in the central of the detector and that measured using the Semiflex ionization chamber placed in the center of a cylindrical phantom show that the deviation doesn’t exceed 3%.In recent years Electronic Portal Imaging Devices (EPIDs) have become indispensable tools for the patient verification set-up in radiotherapy. While EPIDs are primarily used for the assessment of patient positioning and quality control of the accelerator parameters, they also represent an attractive method for the dose verification. Therefore, for their use in dosimetry, it is necessary to investigate their physical characteristics and perform their calibration. The aim of the present study is the development of a calibration procedure and investigation of the stability and the linearity of the signal of an amorphous silicon detector, the a-Si 1000 for Varian systems. The calibration is carried out on the central axis of the beam in the center of the image. To test the signal stability, the detector is placed in the central axis, at a fixed distance of the source with an open field 10 x 10 cm2 and irradiated at regular time intervals, using the 6MV photon beam. The linearity of the signal with the dose an...

The article deals with types of artificial corneal material designed for the eye model, which is designed to calibrate the optical tonometers. This article is focused on the comparison of suitable materials for artificial cornea, measurement and evaluation of the data on the selected contact and non-contact optical tonometers. It sets partial conclusions for the calibration of optical tonometers in ophthalmological practice from the point of view of the materials used.

The implementation of surface-based Monte Carlo simulation technique for oxygen saturation (SaO2) calibration curve estimation is demonstrated in this paper. Generally, the calibration curve is estimated either from the empirical study using animals as the subject of experiment or is derived from mathematical equations. However, the determination of calibration curve using animal is time consuming and requires expertise to conduct the experiment. Alternatively, an optical simulation technique has been used widely in the biomedical optics field due to its capability to exhibit the real tissue behavior. The mathematical relationship between optical density (OD) and optical density ratios (ODR) associated with SaO2 during systole and diastole is used as the basis of obtaining the theoretical calibration curve. The optical properties correspond to systolic and diastolic behaviors were applied to the tissue model to mimic the optical properties of the tissues. Based on the absorbed ray flux at detectors, the OD and ODR were successfully calculated. The simulation results of optical density ratio occurred at every 20 % interval of SaO2 is presented with maximum error of 2.17 % when comparing it with previous numerical simulation technique (MC model). The findings reveal the potential of the proposed method to be used for extended calibration curve study using other wavelength pair.

Laser-induced plasma spectroscopy is performed to determine the elemental compositions of manganese and zinc in potassium bromide (KBr) matrix. This work has utilized Q-switched Nd:YAG laser installed in LIBS2500plus system at fundamental wavelength. The pelletized sample were ablated in air with maximum laser energy of 650 mJ for different gate delays ranging from 0-18 µs. The spectra of samples are obtained for five different compositions containing preferred spectral lines. The intensity of spectral line is observed at its maximum at a gate-delay 0.83 µs and subsequently decayed exponentially with the increasing of gate delay. Maximum signal-to–background ratio of Mn and Zn were found at gate delays of 7.92 and 7.50 µs, respectively. Initial calibration curves show bad data fitting, whereas the locally normalized intensity for both spectral lines shows enhancement since it is more linearly regressed. This study will give a better understanding in studying the plasma emission and the spectra analysis.At...

Shear-sensitive liquid crystals may be used for panoramic flow diagnostics. To reduce calibration time and liquid crystals consumption the possibility of application of the variable cross-section channel are considered in the paper. Short introduction into technique are given. The results of numerical simulation of flow in a modified calibration channel are presented. It was obtained the geometry under consideration (wedge 2.9°) permits to increase the range of the wall shear stresses τw more than twofold in comparison with constant cross section channel. Shear stress measurements by liquid crystals on the wedge surface was shown good coincidence with numerical data.

PTB has more than 20 years of experience in the calibration of space-based instruments using synchrotron radiation to cover the UV, VUV and X-ray spectral range. New instrumentation at the electron storage ring Metrology Light Source (MLS) opens up extended calibration possibilities within this framework. In particular, the set-up of a large vacuum vessel that can accommodate entire space instruments opens up new prospects. Moreover, a new facility for the calibration of radiation transfer source standards with a considerably extended spectral range has been put into operation. Besides, characterization and calibration of single components like e.g. mirrors, filters, gratings, and detectors is continued.

The use of semiconductor diodes at the Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran has been essential for in-vivo dose verification of treatments in Radiation Therapy. Three types of semiconductor diodes, two for photons of low (6 and 10 MV) and high (15 MV) energies; one for electron beams were characterized. The entrance and exit calibration factors for photons and the entrance calibration factors for electrons were obtained under standard conditions in a phantom of solid water using cylindrical and plane parallel ionization chambers for photons and electrons, respectively. Also, the signal diode as a function of monitor units and the angular dependence for photon and electron beams were analyzed; and the source surface distance and field size dependences for photons were determined. The results show that the signal is linear with monitor units and depends on beam quality, increases as a function of angle of incidence and field size and decreases with source surface distance.

In order to unveil the mystery of ultra-high energy cosmic rays (UHECRs), the planned fluorescence telescope JEM-EUSO (Extreme Universe Space Observatory on-board Japanese Experiment Module) will observe extensive air showers induced by UHECRs from the International Space Station (ISS) orbit with a huge acceptance. The JEM-EUSO instrument consists of Fresnel optics and a focal surface detector with 5000 multi-anode photomultiplier tubes (MAPMTs), 300000 channels in total. For fluorescence detection of cosmic rays it is essential to calibrate the detector pre-flight with utmost precision and to monitor the performance of the detector throughout the whole mission time. For that purpose a calibration stand on-ground was built to measure precisely the performance of Hamamatsu 64 pixel MAPMTs that are planned to be used for JEM-EUSO. To investigate the suitability of alternative detector devices, further research is done with state-of-the-art silicon photomultipliers (SiPMs), namely Hamamatsu multi-pixel photon counters (MPPCs). These will also be tested in the calibration stand and their performance can be compared to conventional photomultiplier tubes.

For the development of the calibration method of the emissivity in IR light on the divertor plate in ITER divertor IR thermography system, the laboratory experiments have been performed by using IR instruments. The calibration of the IR camera was performed by the plane black body in the temperature of 100–600 degC. The radiances of the tungsten heated by 280 degC were measured by the IR camera without filter (2.5–5.1 μm) and with filter (2.95 μm, 4.67 μm). The preliminary data of the scattered light of the laser of 3.34 μm that injected into the tungsten were acquired.

Laser Doppler Profile Sensor (LDPS) is a promising technology, which is developed basing on a Laser Doppler Anemometer (LDA) with both the transverse velocity of the object passing the measurement volume can be measured. To realize more precise evaluation of systematic errors and the improvement of the velocity measurement accuracy, a new calibration method- Four Points Method-is proposed in this article, which is considered as the calibration technique with smaller estimated uncertainty on velocity calibration, better operability and less time consuming comparing with the current calibration method of LDPS.

The KM3NeT collaboration aims at the construction of a multi-km3 high-energy neutrino telescope in the Mediterranean Sea consisting of a matrix of pressure resistant glass spheres holding each one a set (31) of small area photomultipliers. The main goal of the telescope is to observe cosmic neutrinos through the Cherenkov light induced in sea water by charged particles produced in neutrino interactions with the surrounding medium. A relative time calibration between photomultipliers of the order of 1 ns is required to achieve an optimal performance. Due to the high volume to be covered by KM3NeT, a cost reduction of the different systems is a priority. To this end a very low price calibration device, the so called Nanobeacon, has been designed and developed. At present one of such devices has already been integrated successfully at the KM3NeT telescope and eight of them in the Nemo Tower Phase II. In this article the main properties and operation of this device are described.

Flat Calibrators (FC) are an option for calibration of infrared thermometers (IT) with a fixed large target. FCs are neither blackbodies, nor gray-bodies; their spectral emissivity is lower than one and depends on wavelength. Nevertheless they are used as gray-bodies with a nominal emissivity value. FCs can be calibrated radiometrically using as reference a calibrated IR thermometer (RT). If an FC will be used to calibrate ITs that work in the same spectral range as the RT then its calibration is straightforward: the actual FC spectral emissivity is not required. This result is valid for any given fixed emissivity assessed to the FC. On the other hand, when the RT working spectral range does not match with that of the ITs to be calibrated with the FC then it is required to know the FC spectral emissivity as part of the calibration process. For this purpose, at CENAM, we developed an experimental setup to measure spectral emissivity in the infrared spectral range, based on a Fourier transform infrared spec...

A new method to calibrate the satellite sensors of high spatial resolution is proposed. This method requires the registration of signals from two (or more) closely located test pixels and enables significantly simplifying and improving the accuracy of the radiation calibration of satellite sensors. To implement this method one needs to measure the atmosphere optical thickness, spectral albedo and reflection functions of test sites, and irradiance of the surface. Compared with traditional calibration process, new method eliminates the need of a priori knowledge of the vertical structure of atmosphere, the necessity to calculate radiative transfer in the atmosphere-underlying surface system and an additional allowance for the influence of the neighboring pixels in the signal registered by the satellite sensor. The simulation performed showed the use of this new technique provides noticeable improvement of radiation calibration of satellite sensors with high spatial resolution.

The cavity-type high temperature blackbody (HTBB) models of BB3200/3500 series are the most spread among metrological institutes worldwide as sources for radiometry and radiation thermometry, due to their ultra high working temperatures, high emissivity and stability. The materials of radiating cavities are graphite, pyrolytic graphite (PG) and their combination. The paper describes BB2000/40 blackbody with graphite-tube cavity that was developed for calibration of radiation thermometers at SCEI (Singapore). The peculiarity of BB2000/40 is a possibility to use it, besides calibration of pyrometers, as an instrument for thermocouples calibration. Operating within the temperature range from 900 °C to 2000 °C, the blackbody has a wide cavity opening of 40 mm. Emissivity of the cavity, with PG heater rings replaced partly by graphite elements, was estimated as 0.998 ± 0.0015 in the spectral range from 350 nm to 2000 nm. The uniformity along the cavity axis, accounting for 10 °C, was measured using a B-type thermocouple at 1500 °C. The BB2000/40, if necessary, can be easily modified, by replacing the graphite radiator with a set of PG rings, to be able to reach temperatures as high as 3200 °C. The HTBB utilizes an optical feedback system which allows temperature stabilization within 0.1 °C. This rear-view feedback allows the whole HTBB aperture to be used for measurements.

This work describes a computer algorithm for automatic extraction of the energy calibration parameters from a Rutherford Back-Scattering Spectroscopy (RBS) spectrum. Parameters like the electronic gain, electronic offset and detection resolution (FWHM) of a RBS setup are usually determined using a standard sample. In our case, the standard sample comprises of a multi-elemental thin film made of a mixture of Ti-Al-Ta that is analyzed at the beginning of each run at defined beam energy. A computer program has been developed to extract automatically the calibration parameters from the spectrum of the standard sample. The code evaluates the first derivative of the energy spectrum, locates the trailing edges of the Al, Ti and Ta peaks and fits a first order polynomial for the energy-channel relation. The detection resolution is determined fitting the convolution of a pre-calculated theoretical spectrum. To test the code, data of two years have been analyzed and the results compared with the manual calculations done previously, obtaining good agreement.

Optical calibration of the BigBite spectrometer for the E05‐102 experiment at Jefferson Lab has been performed. In this paper properties of the BigBite spectrometer and its detector package will be described. Basic ideas and techniques for optical calibration will be explained. For the reconstruction of the BigBite target variables the transport‐matrix formalism has been considered. The process of calibration is explained in detail, together with the latest results. σ‐resolutions of the reconstruction are 1.2 cm for vertex position, 11 mrad for in‐plane angle and 17 mrad for out‐of‐plane angle. Robustness of the calibration algorithm has also been investigated. Results of the scintillation plane gain matching will be shown. Precise calibration of this detector is crucial for particle‐identification and energy determination.

The Physikalisch-Technische Bundesanstalt (PTB), Germany's national metrology institute, is responsible for the realization and dissemination of the legal units in Germany. Within this mission, PTB has been using synchrotron radiation for the realization of the radiometric units in the spectral range from the UV to the X-ray region for more than 25 years. Prominent examples for calibration work using synchrotron radiation performed by PTB within the framework of solar or atmospheric research refer, e.g., to the SUMER and CDS spectrometers of the SOHO mission, the LYRA mission, or the SOL-ACES and the SOLSPEC instruments on ISS.

Mini TEPCs are cylindrical gas proportional counters of 1 mm or less of sensitive volume diameter. The lineal energy calibration of these tiny counters can be performed with an external gamma-ray source. However, to do that, first a method to get a simple and precise spectral mark has to be found and then the keV/μm value of this mark. A precise method (less than 1% of uncertainty) to identify this markis described here, and the lineal energy value of this mark has been measured for different simulated site sizes by using a 137Cs gamma source and a cylindrical TEPC equipped with a precision internal 244Cm alpha-particle source, and filled with propane-based tissue-equivalent gas mixture. Mini TEPCs can be calibrated in terms of lineal energy, by exposing them to 137Cesium sources, with an overall uncertainty of about 5%.

The wavelength accuracy of traditional spectrograph calibration software routines relies heavily on user input and familiarity with spectroscopic techniques. A simple misunderstanding in programmatic procedures or misfit of emission lines can easily result in an inaccurate calibration. After such calibration routines terminate, there is typically no way of determining wavelength accuracy without subsequent peak fitting of emission line spectra for comparison. Furthermore, adjusting calibration parameters to optimize observed spectral dispersion across the focal plane of an imaging spectrograph is not a trivial task and one usually left for the user to determine.It is historically the case that Raman spectra collected with dispersive spectrometers are generally not corrected for the instrumental response function. Spectra obtained from different instruments may therefore show variations in relative peak intensities as a result of the wavelength dependant optical properties of the instrument and quantum eff...

In this paper, a novel measurement technology for ultra-low frequency vibration using orthogonal homodyne interferometer is introduced. The system can calculate the real-time velocity and the acceleration process accurately, and the target displacement under test can reach one meter. The experiment results demonstrate that the proposed method can realize real-time absolute calibration for the transducer undergoing the effects of ultra-low frequency and large amplitude.

The CUORE experiment will search for neutrinoless double beta decay (0nDBD) of 130Te using an array of 988 TeO_2 bolometers operated at 10 mK in the Laboratori Nazionali del Gran Sasso (Italy). The detector is housed in a large cryogen-free cryostat cooled by pulse tubes and a high-power dilution refrigerator. The TeO_2 bolometers measure the event energies, and a precise and reliable energy calibration is critical for the successful identification of candidate 0nDBD and background events. The detector calibration system under development is based on the insertion of 12 gamma-sources that are able to move under their own weight through a set of guide tubes that route them from deployment boxes on the 300K flange down into position in the detector region inside the cryostat. The CUORE experiment poses stringent requirements on the maximum heat load on the cryostat, material radiopurity, contamination risk and the ability to fully retract the sources during normal data taking. Together with the integration into a unique cryostat, this requires careful design and unconventional solutions. We present the design, challenges, and expected performance of this low-temperature energy calibration system., Comment: To be published in the proceedings of the 13th International Workshop on Low Temperature Detectors (LTD), Stanford, CA, July 20-24, 2009

Most of the physics analyses at a hadron collider rely on a precise measurement of the energy of jets in the final state. This requires a precise in situ calibration of the calorimeter with the final detector setup. We present the basic procedure and results of the in situ gain calibration of the D0 HCAL in Run II. The gain calibration works on top of the pulser‐based calibration of the readout electronics and is based entirely on collision data.

In the present study, CR39 track etch detectors were calibrated using 600 A MeV Si14+ ion beam by coneheight distribution method using optical microscope DM 6000 M system installed with Leica QWin Plus software. The CR39 detectors just before and just after the target were calibrated. The response points were fitted with polynomials of second degree and all the points are within the limits of experimental errors.

Stereoscopy is an ideal method to investigate three‐dimensional dynamic processes in dusty plasmas. With more than two (three in our case) cameras, a three‐dimensional reconstruction of the recorded particle structures is possible. This enables investigations on novel dynamic phenomena of dusty plasmas. For the camera calibration of a multi‐view stereo setup, two methods are described: First, recording a target in different orientations, and second, calibrating the system inherently from the dust‐particle images.

A new method for the efficiency calibration of Ge detectors efficiency in measurements with large sources is proposed. To check the reliability of the method, a standard large source was produced and the results are compared to the ones obtained using the proposed method. The preliminary results point to the needs of increasing statistical measurements to allow for a more accurate evaluation of the method.

The Galway Astronomical Stokes Polarimeter (GASP) is an ultra‐high‐speed, full Stokes, astronomical imaging polarimeter based upon a Division of Amplitude Polarimeter. It has been developed to resolve extremely rapid (∼microsecond) variations in objects such as optical pulsars and magnetic CVs. The polarimeter has no moving parts or modulated components, so the complete Stokes vector can be measured from just one exposure—making it unique to astronomy—and the time required for the complete determination of the Stokes vector is limited only by detectors and photon fluxes. The polarimeter utilizes a modified Fresnel rhomb, which acts as a highly achromatic quarter wave plate and a beamsplitter (referred to as an RBS). We present a detailed description of the design process for the RBS and other optics of the polarimeter, and give a theoretical analysis of its expected performance. Calibration is an important, and difficult, issue with all polarimeters, but particularly in astronomical polarimeters. We give a detailed description of calibration techniques appropriate to this type of polarimeter—particularly a version of the Eigenvalue Calibration Method of Compain & Drevillon.

In this work, a calibration method based only in the use of a continuous neutron source as reference is presented. After the silver foil reached activation steady state, the neutron source was removed. The accumulated were analyzed by the method of linear least squares.

We have been attempting to establish an absolute scale of spectral radiance in ultraviolet and vacuum ultraviolet regions by using synchrotron radiation as a primary standard light source and also attempting to calibrate an under‐test light source by comparing the under‐test source with the primary standard light source. A calibration system consisting of a focusing mirror, a monochromator and a detector was introduced for the calibration. If the efficiency of the calibration system were constant, the calibration could be done only by comparing the detector signals obtained from measuring each of the light sources. However the efficiency of the calibration system differs with each of the light sources because the primary and under‐test light sources differ in terms of polarization state, and the transmittance or reflectance of the optical element depends on incident light polarization and the efficiency of the calibration system, and hence also depends on incident light polarization. Consequently, determining the polarization dependence of the calibration system is necessary for the calibration, as is comparing the detector signals. Furthermore, if the polarization dependence of the focusing mirror or the grating of the monochromator in the calibration system is not uniform, it is necessary to make a map showing the polarization dependence of the calibration system versus the vertical and horizontal angles at which the radiation of each light source enters the calibration system. We evaluated the polarization dependence of the calibration system on the vertical angle and evaluated the uncertainty of the spectral radiance calibration due to the angular distribution.

Recently, terahertz ray imaging has emerged as one of the most promising new NDE techniques, and new systems are being developed for applications. In this work, we conducted system calibration on a new time‐domain spectroscopy system, and then utilized this system to characterize glass‐fiber composite plates and polyimide resin disks. Extensive experimental measurements in thru‐transmission mode were made to map out the T‐ray beam pattern in free space as well as to scan these two test materials. Material properties such as index of fraction and absorption coefficient are of the primary interest. Both results were shown in good agreement with known data. Using these characterized material properties, we also demonstrated accurate modeling of the T‐ray signal propagating through the polyimide resin disk.

A temperature reference system for calibrating fluorescence‐based sensors was developed. The system is based on a special thermostatic chamber and on an electro‐optic system equipped with a fiber‐optic scanner. A thin layer of the sensing material to be calibrated can be coated onto a temperature‐controlled reference surface, which is housed inside the thermostatic chamber. It was designed in such a way as to operate under different conditions (from vacuum to atmospheric pressure) in order to evaluate the effect of the surrounding fluid on the surface temperature measurements. The reference surface can be heated both radially, by a wire‐wound heater, and axially, by a thermoelectric cooler. Experimental investigations were carried out in the temperature range −50 °C to about 200 °C. The results showed a temperature stability of better than 0.03 °C and a surface temperature uniformity within 0.02 °C. The system was used to characterize a sensitive phosphor. The phosphor calibration curve was thus obtained, with a single‐point repeatability of better than 0.1 °C. The spatial temperature uniformity of the phosphor‐coated surface was also investigated by using the built‐in fiber‐optic scanner in both environments. The results showed a temperature uniformity within 0.1 °C.

This work presents the results of the design study, investigations of the features and a calibration of double-slit ion energy analyzer prototype at the test-bench in IPP NSC KIPT, Kharkov, Ukraine, with beam energy up to 10 keV. Hitherto obtained accuracy for both analyzer slits is ΔG−2×10−3 and ΔF−3×10−3, which is limited by the existing step motor accuracy 0.1 mm for entrance slits moving. The presented study work is considered as the first step to the multi-slit analyzer elaboration.

We present the current on‐orbit calibration and operational plans for the Swift XRT. The XRT is a largely autonomous instrument and requires very little manual commanding for normal operations. A detailed calibration plan is being developed to verify the instrumental performance on‐orbit, including effective area, point spread function, vignetting, spectroscopic performance, and timing accuracy. Operational plans include regular calibration measurements using on‐board calibration sources as well as periodic calibration observations using celestial targets.

The energy calibration and the measurement of spectral resolving power (E/▵E) of the monochromator are important, especially in near‐edge x‐ray absorption fine structure (NEXAFS) and x‐ray photoemission spectroscopy (XPS) application. For the soft x‐ray beam lines covering 100 – 1000 eV photon energy range, the best way of these is to use a gas cell and an XPS setup with a well‐defined work function and a cooling system. Typically, the N 1s → π* absorption spectrum has been used as a reference for energy calibration and the visibility of the spectrum has been a good measure of the monochromator energy resolution. However, the gas cell is rather inconvenient in case of frequent uses, because it needs a dedicated experimental setup. In this manuscript, we introduce a solid sample that can be used for the energy calibration and for the measurement of spectral resolving power (RP) of the monochromator. The sample is a plasma nitrided SiON. The N 1s absorption spectrum of the sample at room temperature shows a...

Extreme ultraviolet lithography, operating at a wavelength of about 13.5 nm, will require high‐repetition‐rate pulsed sources with average power outputs of over 100 W. As the output of the sources approaches this level, the low‐power, continuous‐wave calibrations of the detectors used to determine the source output will no longer be valid. The National Institute of Standards and Technology (NIST) is currently in the process of commissioning a system for the calibration of Extreme ultraviolet detectors under pulsed conditions similar to those produced by potential sources for extreme ultraviolet lithography. This system incorporates a laser‐produced plasma source based on a Kr droplet target. The plasma’s output is collimated by a grazing incidence parabolic reflector and split by a Mo/Si multilayer beamsplitter to provide two channels of illumination. Each channel is refocused onto filtered detectors to provide two signals that are proportional to the plasma Extreme Ultraviolet (EUV) output. Calibration i...

Methodologies for calibrating heat‐flux sensors designed for direct measurement of heat‐transfer at a surface are presented. These sensors, extensively used in fire‐test methods and aerospace applications, vary in range from a few kW/m2 to in excess of 500 kW/m2. Traceable source‐ and detector‐based techniques using blackbody radiation are described to cover the wide range of calibration. Calibration results on typical sensors from three blackbody facilities: 25 mm and 51 mm diameter heated graphite tubes and a 23 cm diameter spherical cavity, are presented. These results demonstrate the equivalence between the source‐ and detector‐based techniques in the range from 50 kW/m2 to 200 kW/m2, and also the superiority of detector‐based calibration when reflected radiation effects are important. The problems associated with extending the calibration techniques to high heat‐flux levels by inserting the sensor inside a blackbody cavity are also discussed.

An Asia‐Pacific Metrology Program (APMP) key comparison of radiance temperature in 0.65 μm was carried out from 1997 to 2000 among seven institutes: NMIJ, KRISS, NIM, CSIRO, NMC, KIM‐LIPI and ITRI. Afterward an APMP supplementary comparison of radiance temperature in 0.9 μm was started. Both of the comparisons employ a transfer standard radiation thermometer as a transfer instrument. This paper describes the calibration and characterization of the 0.65 μm transfer‐standard radiation thermometers. The 0.65 μm thermometer was calibrated according to the ITS‐90. A copper‐point calibration, spectral responsivity measurement and nonlinearity measurement were carried out. The measured spectral responsivity was multiplied by the Planck equation and was integrated over wavelength. The coefficient was determined by the copper‐point calibration. The integral scale of the output V at temperature T was approximated by an interpolation equation, V(T)=C/[exp{c2/(AT+B)}−1]. Here c2 is the second radiation constant and t...

NIST and International SEMATECH are developing single‐crystal reference materials for use in evaluating and calibrating critical dimension (CD) metrology tools. Primary calibration of these reference materials uses a high‐resolution transmission electron microscopy (HRTEM) image of the cross section of the feature at sufficient magnification to resolve and count the individual lattice planes; the transfer calibration is provided by complementary metrology techniques. In previous work, electrical test structure metrology served as the transfer metrology. Recent work has centered on evaluating the performance of these CD reference materials in the metrology tools which we expect will comprise the bulk of their usage: the critical dimension scanning electron microscope (CD‐SEM) and atomic force microscope (AFM). In particular, a critical dimension AFM (CD‐AFM) is particularly useful. This technique uses flared tips and two‐dimensional feedback to allow scanning of near‐vertical sidewalls. It is currently expected that CD‐AFM will serve as an additional transfer calibration technique. Additionally, since earlier samples showed a high variability in the appearance of the samples, additional screening using the CD‐SEM and AFM will provide significant improvement to verify that each device meets minimal uniformity characteristics.

The efficiency of a Si(Li) detector was determined experimentally and adequately simulated with the GEANT4 code in the energy range from 5 to 27 keV. The point‐like sources used were 55Fe, 65Zn, 85Sr, 109Cd and 241Am. For simulation of the detector response we have used a recent version of GEANT4 8.0 (Released 10 February 2006). In this version, all needed electro‐magnetic processes are considered, essentially Compton scattering, photo‐electric effect, Raleigh effect, multiple scattering, fluorescence and Auger effect and ionization. The detector was firstly modeled using its technical dimensions supplied by the manufacturer. Then these dimensions were optimized in order to reproduce the experimental efficiency. An agreement better than 98 % for almost all the energy lines (5 to 27 keV) between experimental and simulated efficiency values was obtained by adjusting some detector parameters. Those optimized parameters are the front dead layer of the crystal which is increased by 1.3 μm and the crystal‐to‐wi...

Due to shrinking size of lithographic feature and limitations of SEM process, the native accuracy of CD‐SEM instrument falls outside of ITRS requirements for characterization of lithographic structures for technology node 45 nm and smaller. This work provides overview and feasibility study of metrology system that can deliver accurate CD measurements from CD‐SEM by using combination of image metrology and SEM beam modeling methods for automated evaluation and correction of CD‐SEM bias. Open issues and further metrology needs are also discussed.

We present the in-flight calibration results of the detector response matrices of the X-ray instrument, Wide-field X-ray Monitor (WXM), on board the HETE-2 satellite. WXM consists of four one-dimensional position-sensitive proportional counters and two sets of one-dimensional coded aperture. Its energy range is 2-25 keV.The detector response matrix (DRM) of WXM is calculated numerically using the ground measurements for each anode wire. It is then calibrated with the observation of the Crab nebula in December 2001 and January 2002. The spectral parameters and the normalization of the spectra are investigated at various incident angles, and compared with the known values in literature. With the current DRM, the derived spectral parameters are mostly consistent with the values in literature, expect for 10-20% uncertainty in normalization for individual anode wires, and at large incidence angles.

The early performance verification phase of the INTEGRAL satellite foresees basically several different observations as part of commissioning of the on-board instruments. The Cygnus region, two empty fields and the Crab have been selected as targets. These observations are necessary in order to obtain imaging performances for point sources and for crowded fields, spectral cross-calibration between the on-board instruments, a background variation study, absolute flux and timing calibration. We report simulation results for the IBIS coded mask telescope of planned calibrations concerning Crab and Cygnus X-1, performed in both staring and dithering observing modes. A Monte Carlo code including a full geometrical and physical model of the instrument has been used.

This contribution covers the absolute calibration to better than 1% of the in-beam proton polarimeters at IUCF. The polarimeters observe p+d elastic scattering from thin CD2 targets at θlab(d)=42.6°. The calibration standard was double scattering using a 12C first target and the focal plane polarimeter of the K600 magnetic spectrometer. This procedure gave the beam polarization and the analyzing powers from both targets. Systematic errors are discussed.

The utilization of radiation thermometers by industry is increasing at a significant rate. At the same time, the need to establish the traceability of the resulting measurements to national standards has never been more important. NRC has responded to this demand by establishing a calibration facility comprising both variable‐temperature and fixed‐point blackbody cavities spanning the range from −50 °C to 2500 °C.

This paper presents the design and construction of a new type of precise photoelectric pyrometer, a transfer standard in the range of 800 °C to 3200 °C. The modified calibration methods have been applied at NIM to improve the dissemination of the ITS‐90 with the new pyrometers. A resolution at the copper point of approximately 1 mK and an estimated standard uncertainty of 0.22 °C to 0.8 °C from 800 °C to 2200 °C were obtained. Comparison measurements performed between the pyrometers and primary standard lamps from 800 °C up to 1700 °C show agreement within 0.3 °C.

The HETE Soft X‐ray Camera (SXC) uses X‐ray CCDs and a micro‐fabricated coded aperture mask to image X‐ray sources with sub‐arcminute accuracy over a steradian field of view. Calibration of imaging with observations of the Crab and Sco X‐1 is described. The accuracy of SXC localizations is determined trough observations of known steady and transient galactic X‐ray sources and sensitivity to GRBs is estimated through detections of steady and transient Galactic X‐ray sources. [NB: As of October 2002, the SXC had localized 4 GRBs to arcminute accuracy].

In this paper, we report some recent developments of the diffraction-based absolute X-ray energy calibration method. In this calibration method, high spatial resolution of the measured detector offset is essential. To this end, a remotely controlled long-translation motorized stage was employed instead of the less convenient gauge blocks. It is found that the precision of absolute X-ray energy calibration (ΔE/E) is readily achieved down to the level of 10−4 for high-energy monochromatic X-rays (e.g. 80 keV). Examples of applications to pair distribution function (PDF) measurements and energy monitoring for high-energy X-rays are presented.