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Purpose To reduce imaging artifacts and improve image quality of a specific proton computed tomography (pCT) prototype scanner by combining pCT data acquired at two different incident proton energies to avoid protons stopping in sub-optimal detector sections. Methods Image artifacts of a prototype pCT scanner are linked to protons stopping close to internal structures of the scanner’s multi-stage energy detector. We aimed at avoiding such protons by acquiring pCT data at two different incident energies and combining the data in post-processing from which artifact-reduced images of the relative stopping power (RSP) were calculated. Energy-modulated pCT (EMpCT) images were assessed visually and quantitatively and compared to the original mono-energetic images in terms of RSP accuracy and noise. Data were acquired for a homogeneous water phantom. Results RSP images reconstructed from the mono-energetic datasets displayed local image artifacts which were ring-shaped due to the homogeneity of the phantom. The merged EMpCT dataset achieved a superior visual image quality with reduced artifacts and only minor remaining rings. The inter-quartile range (25/75) of RSP values was reduced from 0.7 % with the current standard acquisition to 0.2 % with EMpCT due to the reduction of ring artifacts. In this study, dose was doubled compared to a standard scan, but we discuss strategies to reduce excess dose. Conclusions EMpCT allows to effectively avoid regions of the energy detector that cause image artifacts. Thereby, image quality is improved.

Purpose: Currently, calculations of proton range in proton therapy patients are based on a conversion of CT Hounsfield Units of patient tissues into proton relative stopping power. Uncertainties in this conversion necessitate larger proximal and distal planned target volume margins. Proton CT can potentially reduce these uncertainties by directly measuring proton stopping power. We aim to demonstrate proton CT imaging with complex porcine samples, to analyze in detail three-dimensional regions of interest, and to compare proton stopping powers directly measured by proton CT to those determined from x-ray CT scans. Methods: We have used a prototype proton imaging system with single proton tracking to acquire proton radiography and proton CT images of a sample of porcine pectoral girdle and ribs, and a pig's head. We also acquired close in time x-ray CT scans of the same samples, and compared proton stopping power measurements from the two modalities. In the case of the pig's head, we obtained x-ray CT scans from two different scanners, and compared results from high-dose and low-dose settings. Results: Comparing our reconstructed proton CT images with images derived from x-ray CT scans, we find agreement within 1% to 2% for soft tissues, and discrepancies of up to 6% for compact bone. We also observed large discrepancies, up to 40%, for cavitated regions with mixed content of air, soft tissue, and bone, such as sinus cavities or tympanic bullae. Conclusions: Our images and findings from a clinically realistic proton CT scanner demonstrate the potential for proton CT to be used for low-dose treatment planning with reduced margins., Accepted for publication in Medical Physics

The work is dedicated to the discussion of the possibility of creating a position-sensitive detector with high coordinate reconstruction. The paper presents the simulation results and the experimentally obtained data for a prototype detector based on the MA-20 multianode PMT [1] and a linear stack of scintillating crystal or plastic strips. The multianode position-sensitive PMT MA-20 has a semitransparent bi-alkaline photocathode with the size of the sensitive area of 10 × 200 mm2, 10 evaporated type bi-alkaline type dynodes of the same length, and 20 separated anodes. This PM is the invention of the authors. The maximum gain of the dynode system is 106. The stack of scintillating strips made of GSO (gadolinium orthosilicate) crystals with an element size of 3 × 10 × 50 mm3, of BGO (bismuth germanate) crystals with an element size of 5 × 15 × 40 mm3, and finally stack of strips made of a plastic scintillator with an element size of 5 × 10 × 200 mm3 were used for experimental measurement of a spatial resolution of the detector prototype. Space resolution was determined by the position of the center of gravity of charges of neighboring anodes [2]. As a source of radiation, the collimated 137Cs (γ 0.662 MeV) and 90Sr (β− 2.283 MeV) were used, the measured number of photoelectrons is 10–20 of one element of the stack, depending on the scintillating strip type. The use of a multi-anode photomultiplier in combination with the stack of crystal or plastic scintillators allows one to get a simple linear detector with high performance in spatial resolution and also with a low level of intrinsic noise in comparison, for example, with silicon PMT. A resolution simulation was performed for a system consisting of a one-dimensional stack of scintillation strips placed on the photocathode of a multi-anode PMT for different values of the strips width and the number of photoelectrons of one strip. The experimental dependences of the signal value versus position of optical fiber with a diameter of 1 mm on the photocathode of the 20 anodes PMT were also measured that allowed to specify the coordinate resolution for the described detector. As a result of processing the collected data, spatial resolution was obtained at the level of 1 mm. The obtained results are in good agreement with the simulation results.

One of the major challenges to proton beam therapy at this time is the uncertainty of the true range of a clinical treatment proton beam as it traverses the various tissues and organs in a human body. This uncertainty necessitates the addition of greater “margins” to the planning target volume along the direction of the beam to ensure safety and tumor target coverage. Proton radiography holds promise as both an image-guidance method for proton beam therapy and as a means of estimating particle beam range in the clinic. In this brief report, we present some of the first real and reconstructed proton radiographs using our particular system. Our qualitative review of these images indicates that this method has excellent potential as a proton radiography-based image guidance system. Based on the encouraging results of our preliminary work, more rigorous and quantitative analyses will be performed shortly and we shall continue to explore the potential of this approach for addressing the particle beam range uncertainty issue.

Verification of patient specific proton stopping powers obtained in the patient treatment position can be used to reduce the distal margins needed in particle beam planning. Proton radiography can be used as a pre-treatment instrument to verify integrated stopping power consistency with the treatment planning CT. Although a proton radiograph is a pixel by pixel representation of integrated stopping powers, the image may also be of high enough quality and contrast to be used for patient alignment. This investigation qualifies the accuracy and image quality of a prototype proton radiography system on a clinical proton delivery system. We have developed a clinical prototype proton radiography system designed for integration into efficient clinical workflows. We tested the images obtained by this system for water-equivalent thickness (WET) accuracy, image noise, and spatial resolution. We evaluated the WET accuracy by comparing the average WET and rms error in several regions of interest (ROI) on a proton radiograph of a custom peg phantom. We measured the spatial resolution on a CATPHAN Line Pair phantom and a custom edge phantom by measuring the 10% value of the modulation transfer function (MTF). In addition, we tested the ability to detect proton range errors due to anatomical changes in a patient with a customized CIRS pediatric head phantom and inserts of varying WET placed in the posterior fossae of the brain. We took proton radiographs of the phantom with each insert in place and created difference maps between the resulting images. Integrated proton range was measured from an ROI in the difference maps., 11 pages, 7 figures, Submitted to Medical Physics

Purpose: To demonstrate a proton imaging system based on well-established fast scintillator technology to achieve high performance with low cost and complexity, with the potential of a straightforward translation into clinical use. Methods: The system tracks individual protons through one (X, Y) scintillating fiber tracker plane upstream and downstream of the object and into a 13 cm-thick scintillating block residual energy detector. The fibers in the tracker planes are multiplexed into silicon photomultipliers (SiPMs) to reduce the number of electronics channels. The light signal from the residual energy detector is collected by 16 photomultiplier tubes (PMTs). Only four signals from the PMTs are output from each event, which allows for fast signal readout. A robust calibration method of the PMT signal to residual energy has been developed to obtain accurate proton images. The development of patient-specific scan patterns using multiple input energies allows for an image to be produced with minimal excess dose delivered to the patient. Results: The calibration of signals in the energy detector produces accurate residual range measurements limited by intrinsic range straggling. We measured the water-equivalent thickness (WET) of a block of solid water (physical thickness of 6.10 mm) with a proton radiograph. The mean WET from all pixels in the block was 6.13 cm (SD 0.02 cm). The use of patient-specific scan patterns using multiple input energies enables imaging with a compact range detector. Conclusions: We have developed a prototype clinical proton radiography system for pretreatment imaging in proton radiation therapy. We have optimized the system for use with pencil beam scanning systems and have achieved a reduction of size and complexity compared to previous designs., 11 pages, 8 figures, Accepted Manuscript

Proton computed tomography (pCT) has high accuracy and dose efficiency in producing spatial maps of the relative stopping power (RSP) required for treatment planning in proton therapy. With fluence-modulated pCT (FMpCT), prescribed noise distributions can be achieved, which allows to decrease imaging dose by employing object-specific dynamically modulated fluence during the acquisition. For FMpCT acquisitions we divide the image into region-of-interest (ROI) and non-ROI volumes. In proton therapy, the ROI volume would encompass all treatment beams. An optimization algorithm then calculates dynamically modulated fluence that achieves low prescribed noise inside the ROI and high prescribed noise elsewhere. It also produces a planned noise distribution, which is the expected noise map for that fluence, as calculated with a Monte Carlo simulation. The optimized fluence can be achieved by acquiring pCT images with grids of intensity modulated pencil beams. In this work, we interfaced the control system of a clinical proton beam line to deliver the optimized fluence. Using three phantoms we acquired images with uniform fluence, with a constant noise prescription, and with an FMpCT task. Image noise distributions as well as fluence maps were compared to the corresponding planned distributions as well as to the prescription. Furthermore, we propose a correction method that removes image artifacts stemming from the acquisition with pencil beams having a spatially varying energy distribution that is not seen in clinical operation. RSP accuracy of FMpCT scans was compared to uniform scans and was found to be comparable to standard pCT scans. While we identified technical improvements for future experimental acquisitions, in particular related to an unexpected pencil beam size reduction and a misalignment of the fluence pattern, agreement with the planned noise was satisfactory and we conclude that FMpCT optimized for specific image noise prescriptions is experimentally feasible.

Proton radiography is one of the most important and actual areas of research that can significantly improve the quality and accuracy of proton therapy. Currently, the calculation of the proton range in patients receiving proton therapy is based on the conversion of Hounsfield CT units of the patient's tissues into the relative stopping power of protons. Proton radiography is able to reduce these uncertainties by directly measuring proton stopping power. The study demonstrates the possibility of Protom synchrotron-based proton therapy facilities to operate in a special mode which makes it possible to implement proton radiography. This work presents the status of the new low beam intensity extraction mode. The paper describes algorithms of low flux beam control, calibration procedures and experimental measurements. Measurements and calibration procedures were performed with certified Protom Faraday Cup, PTW Bragg Peak Chamber and specially designed experimental external.

The observation of hydrogenlike πK atoms, consisting of π^{-}K^{+} or π^{+}K^{-} mesons, is presented. The atoms are produced by 24 GeV/c protons from the CERN PS accelerator, interacting with platinum or nickel foil targets. The breakup (ionization) of πK atoms in the same targets yields characteristic πK pairs, called "atomic pairs," with small relative momenta Q in the pair center-of-mass system. The upgraded DIRAC experiment observed 349±62 such atomic πK pairs, corresponding to a signal of 5.6 standard deviations. This is the first statistically significant observation of the strange dimesonic πK atom.

Purpose: The authors present a calibration method for a prototype protoncomputed tomography (pCT) scanner. The accuracy of these measurements depends upon careful calibration of the energy detector used to measure the residual energy of the protons that passed through the object. Methods: A prototype pCT scanner with a cesium iodide (CsI(Tl)) crystal calorimeter was calibrated by measuring the calorimeter response for protons of 200 and 100 MeV initial energies undergoing degradation in polystyrene plates of known thickness and relative stopping power (RSP) with respect to water. Calibration curves for the two proton energies were obtained by fitting a second-degree polynomial to the water-equivalent path length versus calorimeter response data. Using the 100 MeV calibration curve, the RSP values for a variety of tissue-equivalent materials were measured and compared to values obtained from a standard depth-dose range shift measurement using a water-tank. A cylindrical water phantom was scanned with 200 MeV protons and its RSP distribution was reconstructed using the 200 MeV calibration. Results: It is shown that this calibration method produces measured RSP values of various tissue-equivalent materials that agree to within 0.5% of values obtained using an established water-tank method. The mean RSP value of the water phantom reconstruction was found to be 0.995 ± 0.006. Conclusions: The method presented provides a simple and reliable procedure for calibration of a pCT scanner.

Nucl.Instrum.Meth.A634:8-46,2011; This paper describes the mechanical design, the readout chain, the production, testing and the installation of the Silicon Microstrip Tracker of the D0 experiment at the Fermilab Tevatron collider. In addition, description of the performance of the detector during the experiment data collection between 2001 and 2010 is provided.

Detailed measurements of the wavelength shifting fiber response to a stable and reliable light source are presented. Particulars about materials, a double reference method, and measurement technique are included. The fibers studied were several hundred Kuraray, Y-11, multiclad, 1.2-mm outer diameter wavelength shifting fibers, each cut from a reel to about one meter length. The fibers were polished, mirrored, and the mirrors were UV epoxy protected. Each fiber passed quality control requirements before installation. About 94% of the fibers tested have a response within 1% of the overall mean

We present results on the operation and performance characteristics of the Metal/Resistor/Semiconductor (MRS) photodiode. These include measurements of threshold characteristics, noise frequency, dependence of signal amplitude on the applied voltage and temperature, and stability as a function of time and radiation dose. The single photoelectron separation for this photosensor is demonstrated with a light-emitting diode. The response of the photodetector to light produced in scintillator is studied with cosmic ray muons and a 106Ru source. In addition, fiber-sensor alignment issues were evaluated. The results are promising and illustrate the potential use of MRS as photosensors in high energy physics detectors.

The experimental results for the narrow scintillating elements with effective area about 20 cm 2 are reported. The elements were formed from the single piece of scintillator and were read out via wavelength shifting (WLS) fibers with the Metal/Resistor/Semiconductor (MRS) photodiodes on both ends of each fiber. The count rates were obtained using radioactive source 90 Sr, with threshold at about three photoelectrons in each channel and quad coincidences (double coincidences between sensors on each fiber and double coincidences between two neighboring fibers). The formation of the cells from the piece of scintillator by using grooves is discussed, and their performances were tested using the radioactive source by measuring the photomutiplier current using the same WLS fiber. Because effective cell area can be readily enlarged or reduced, this module may be used as an active element for calorimeter or muon system for the design of the future electron–positron linear collider detector. Experimental verification of the performance of the MRS photodiode in a strong magnetic field of 9 T, and the impact a magnet quench at 9.5 T are reported. The measurement method used is described. The results confirm the expectations that the MRS photodiode is insensitive to a strong magnetic field and therefore applicable to calorimetry in the presence of magnetic field. The overall result is of high importance for large multi-channel systems.

The experimental results on the performance of the Metal/Resistor/Semiconductor (MRS) photodiode in the strong magnetic field of 4.4 T, and the possible impact of the quench of the magnet at 4.5 T on sensor's operation are reported. In addition, the experimental results on the performance of the extruded scintillator and WLS fiber, and various LEDs in the magnetic fields of 1.8 and 2.3 T, respectively, are detailed. The measurement method used is being described. The results of the work agree with the expectations that the LED, MRS and scintillator are not exhibiting sensitivity to the magnetic field presence. This result is essential for the design of the future electron–positron linear collider detector.

At the future Facility for Antiproton and Ion Research in Darmstadt (FAIR) a dedicated heavy-ion experiment investigating the properties of highly Compressed Baryonic Matter is proposed (CBM). A key observable of the physics program will be a precise measurement of low-mass vector mesons in their leptonic decay channel. The essential experimental tool for identifying the decay electrons will be a gaseous RICH detector. The concept of this RICH detector will be introduced and discussed.

The MINERνA experiment at Fermilab will use a fully-active scintillator based fine grained neutrino detector and the high rate NuMI neutrino beam. MINERνA will measure low energy neutrino interaction properties and cross sections to a new level of precision. These measurements will be critical input to present and future accelerator-based neutrino oscillation experiments in this energy range.

We present results on the operation and performance characteristics of the MRS (metal/resistor/semiconductor) photodiode. These include measurements of threshold characteristics, noise frequency, dependence of signal amplitude on the applied voltage and temperature, and stability as a function of time and radiation dose. The single photoelectron separation for this photosensor is demonstrated with a light emitting diode. The response of the photodetector to light produced in a scintillator is studied with cosmic ray muons and a 106 Ru source. In addition, fiber-sensor alignment issues were evaluated. The results are promising and illustrate the potential use of MRS as photosensors in high-energy physics detectors.

The ability to distinguish between hadronic W and Z decays is one of the most challenging requirements for the future linear collider detector. Such sensitivity requires unprecedented jet energy resolution, which may be possible with energy-flow algorithms. A calorimeter that is optimized for energy-flow must have fine lateral and longitudinal segmentation. Small scintillating cells with wavelength shifting fibre readout represent an attractive basis for a digital hadron calorimeter that trades dynamic range for superior granularity, at an affordable price. We present the expected jet resolution for such a device, based on Monte Carlo simulations. Then we describe the initial prototyping studies. In particular, detailed studies are presented on cell performance under different combinations of manufacture and assembly.

The ability to distinguish physics signals that share common signatures involving multijet final states is crucial to the success of the future Linear Collider Detector (LCD). This translates into a requirement of attaining unprecedented precision in jet energy measurements. For example, to effectively separate W and Z bosons in their hadronic final states by reconstructing their invariant masses, one will require a jet energy resolution of dE/E

Proton radiography has applications in patient alignment and verification procedures for proton beam radiation therapy. In this paper, we report an experiment which used 200 MeV protons to generate proton energy-loss and scattering radiographs of a hand phantom. The experiment used the first-generation proton computed tomography (CT) scanner prototype, which was installed on the research beam line of the clinical proton synchrotron at Loma Linda University Medical Center. It was found that while both radiographs displayed anatomical details of the hand phantom, the energy-loss radiograph had a noticeably higher resolution. Nonetheless, scattering radiography may yield more contrast between soft and bone tissue than energy-loss radiography, however, this requires further study. This study contributes to the optimization of the performance of the next-generation of clinical proton CT scanners. Furthermore, it demonstrates the potential of proton imaging (proton radiography and CT), which is now within reach of becoming available as a new, potentially low-dose medical imaging modality. © 1982-2012 IEEE.

The RICH detector used in the SPHINX experiment at the Serpukhov accelerator is described. The optical system of this detector consists of two spherical mirrors with focal length of 125 cm. Two matrices with 736 phototubes in total are used for the photocathode. The standard performance characteristics of the detector are a value of 42 cm −1 for N0 and a single hit resolution of 0.5 cm . Particle identification capability of the detector is discussed.

This paper discusses the design and operation of the 1st proton CT scanner for 3D imaging. Reduction of proton range uncertainties and improved dose accuracy in the patient for treatment planning are central goals. A central CT slice acquired by reconstruction of 134 million proton tracks through a 14 cm spherical polystyrene phantom with high and low density inserts is presented.

New projective prototypes of a scintillator/lead sandwich type sampling calorimeter Shashlik with a silicon preshower detector have been constructed and tested with an electron beam at CERN-SPS. The energy resolution is measured to be 8.7%/sqrt(E(GeV)) in stochastic term. 0.330/E(GeV) in noise term and 0.5% in constant term. The angular resolution is better than 70 mrad/sqrt(E(GeV)).

A prototype module for an International Linear Collider (ILC) detector was built, installed, and tested between 2006 and 2009 at CERN and Fermilab as part of the CALICE test beam program, in order to study the possibilities of extending energy sampling behind a hadronic calorimeter and to study the possibilities of providing muon tracking. The "tail catcher/muon tracker" (TCMT) is composed of 320 extruded scintillator strips (dimensions 1000 mm x 50 mm x 5 mm) packaged in 16 one-meter square planes interleaved between steel plates. The scintillator strips were read out with wavelength shifting fibers and silicon photomultipliers. The planes were arranged with alternating horizontal and vertical strip orientations. Data were collected for muons and pions in the energy range 6 GeV to 80 GeV. Utilizing data taken in 2006, this paper describes the design and construction of the TCMT, performance characteristics, and a beam-based evaluation of the ability of the TCMT to improve hadronic energy resolution in a prototype ILC detector. For a typical configuration of an ILC detector with a coil situated outside a calorimeter system with a thickness of 5.5 nuclear interaction lengths, a TCMT would improve relative energy resolution by 6-16 % for pions between 20 and 80 GeV., 23 pages, 18 figures, 4 tables, submitted to JINST

We describe the design and performance of prototype trigger counters for the SDC muon system. The 1.0×48.7×178.7 cm scintillation counters feature compact light guides, use standard 2 in. phototubes, and provide good photoelectron yields (>25) and time resolution (

Proton Computed Tomography (pCT) is being developed in support of proton therapy and treatment planning. The aim of pCT, to reconstruct an accurate map of the stopping power (S.P.) in a phantom and, in the future, in patients, is being pursued with a diverse list of detector systems, using the entire arsenal of tracking and energy detectors developed for High Energy Physics (HEP). The first radiographs and 3D images are being reconstructed with prototype detectors, which will be described. Most of the existing systems are being upgraded to higher proton fluxes to reduce the scanning time.

N. Abel 21, J. Adamczewski 12, D. Adamova 45, M.M. Aggarwal 10, N. Ahmad 2, Z. Ahmad 30, A. Akindinov 36, P. Akishin 16, E. Akishina 16, T. Akishina 16, M. Al-Turany 12, M. Alyushin 39, S. Amar-Youcef 17, V. Ammosov 43, M. Andelic 47, C. Andrei 6, A. Andronic 12, Yu. Anisimov 14, K. Antipin 17, H. Appelshauser 17, A. Arefiev 36, T. Armbruster 23, A. Artamonov 43, E. Atkin 39, M.D. Azmi 2, P.V.K.S. Baba 25, E. Badura 12, S. Baginyan 16, S. Bandyopadhyay 29, N. Baranova 37, G. Bashindzhagyan 37, Z. Basrak 55, V. Baublis 18, S. Belogurov 36, I. Berceanu 6, E. Berdermann 12, A. Berdnikov 50, Y. Berdnikov 50, R. Berendes 40, C. Bergmann 40, D. Bertini 12, C. Besliu 7, O. Bezshyyko 33, P. Bhaduri 30, A. Bhasin 25, A.K. Bhati 10, B. Bhattacharjee 19, A. Bhattacharya 29, Y. Bocharov 39, M. Bogolyubsky 43, L. Boldizsar 9, N. Bondar 18, M. Borysova 34, S. Bottger 21, P. Braun-Munzinger 12, U. Bruning 23, J. Brzychczyk 32, A. Bubak 26, R. Caplar 55, Xu Cai 54, M. Calin 7, G. Caragheorgheopol 6, I. Carevic 47, V. Catanescu 6, A. Chakraborti 29, S. Chatterji 12, Subhasis Chattopadhyay 30, Sukalyan Chattopadhyay 28, Sanatan Chattopadhyay 29, A. Chaus 34, Hongfang Chen 20, Jianping Cheng 3, V. Chepurnov 14, S. Chernenko 14, A. Chernogorov 36, M. Chubarov 49, M. Ciobanu 12, G. Claus 51, V. Covlea 7, D. Cozma 6, M. Csanad 8, N. D’Ascenzo 41, D. Das 28, I. Das 28, V. Davkov 15, K. Davkov 15, M. De22, R. De51, B. Debnath 19, E. Denes 9, Zhi Deng 3, O. Denisova 16, H. Deppe 12, I. Deppner 22, A. Dermenev 35, M. Deveaux 17, M. Dey 30, A. Dorokhov 51, C. Dritsa (IPHC Strasbourg), 12, A. Dubey 30, W. Dulinski 51, A.K. Dutt-Mazumdar 28, T. Dutta 12, D. Dutta 12, M.R. DuttaMajumdar 30, V. Dyatchenko 43, M. Dželalija 47, H. Engel 21, T. Esanu 7, J. Eschke 12, H. Essel 12, O. Fateev 14, R. Ferreira Marques 11, P. Fischer 23, H. Flemming 12, Z. Fodor 9, P. Fonte 11, I. Frohlich 17, H. Froning 23, V. Friese 12, E. Futo 9, I. Gasparic 55, J. Gajda 31, T. Galatyuk 12, V. Galkin 41, A. Galkin 41, G. Gangopadhyay 29, Wenxue Gao 23, C. Garabatos 12, P. Gasik 53, J. Gebelein 21, P. Ghosh 30, Yu. Gilitsky 43, V. Golovatyuk 14, S. Golovnya 43, V. Golovtsov 18, M. Golubeva 35, D. Golubkov 36, A. Golutvin 36, D. Gonzalez-Diaz 12, S. Gorbunov 21, S. Gorokhov 43, D. Gottschalk 21, Ju. Gousakov 15, E. Grosse 13, P. Gryboś 31, A. Grzeszczuk 26, F. Guber 35, A. Gumenuik 39, A. Gupta 25, M. Hartig 17, K. Heidel 13, N. Heine 40, A. Herghelegiu 6, N. Herrmann 22, J. Heuser 12, A. Himmi 51, C. Hohne 12, R. Holzmann 12, Byungsik Hong 46, J. Hutsch 13, A. Ierusalimov 14, S. Igolkin 49, I. Ilyushenko 39, Tae Im Kang 46, M. Irfan 2, Valery Ivanov 16, V. Ivanov 18, Victor Ivanov 16, A. Ivashkin 35, K. Jaaskelainen 51, V. Jakovlev 49, A. Jinaru 7, A. Jipa 7, M. Kachel 31, I. Kadenko 33, H. Kalita 19, B. Kampfer 13, V. Karasev 49, O. Karavichev 35, T. Karavicheva 35, D. Karmanov 37, E. Karpechev 35, E.M. Kashif 2, K. Kasinski 31, Manjit Kaur 10, A. Kazantsev 38, U. Kebschull 21, J. Kecskemeti 9, G. Kekelidze 15, M.M. Khan 2, S.A. Khan 48, A. Khanzadeev 18, Yu. Kharlov 43, F. Khasanov 36, M. Kis 55, Junghan Kim 44, M. Kirejczyk 53, I. Kisel 12, S. Kiselev 36, A. Kiseleva 12, T. Kiss 9, A. Kiss 8, Ch. Klein-Bosing 40, M. Klein-Bosing 40, V. Kleipa 12, A. Kluev 39, K. Koch 12, P. Koczon 12, B. Kolb 12, B. Komkov 18, D. Konstantinov 43, P. Korobchuk 43, M. Korolev 37, I. Korolko 36, N. Korotkova 37, R. Kotte 13, A. Kotynia 12, A. Kovalchuk 34, S. Kowalski 26, M. Koziel 51, M. Krauze 26, C. Kreidel 23, D. Kresan 12, E. Kryshen 18, L. Kudin 18, I. Kudryashov 36, A. Kugel 23, A. Kugler 45, A. Kurepin 35, S. Lochner 12, V. Ladygin 14, C. Lara 21, S. Lashaev 49, A. Laszlo 9, I. Lazanu 7, A. Lebedev (JINR-LIT Dubna) 12, S. Lebedev (JINR-LIT Dubna) 12, Hayoung Lee 44, F. Lemke 23, Cheng Li 20, Yuanjing Li 3, Yulan Li 3, Jin Li 3, V. Lindenstruth 21, S. Linev 12, E. Litvinenko 16, I. Lobanov 43, E. Lobanova 43, P. Loizeau 22, Nuclear Physics A 830 (2009) 942c–944c

The use and parameters of two new devices for multichannel coordinate Cherenkov and scintillation detectors are discussed. The first one is an input element of a multichannel system based on IIs and CCD to realize photoreceivers of 1 m2 working area. The input element (named “elkon”) is a three electrode II with low magification, focusing an image in a 1 mm diameter spot. The elkon-II-CCD system provides a one-photon detection efficiency near 10%. The total number of the independent detection channels is about 103 and 5 × 103 with II photocathode diameters of 40 and 80 mm, respectively. Another way to realize the photodetectors with large sensitive area is to use simple hydrid PMTs, representing the elkon with the built-in MDS-photoelement, operating in avalanche mode.

An extrusion line has recently been installed at Fermilab in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new facility will serve to further develop and improve extruded plastic scintillator. Since polystyrene is widely used in the consumer industry, the logical path was to investigate the extrusion of commercial-grade polystyrene pellets with dopants to yield high quality plastic scintillator. The D0 and MINOS experiments are already using extruded scintillator strips in their detectors. A new experiment at Fermilab is pursuing the use of extruded plastic scintillator. A new plastic scintillator strip is being tested and its properties characterized. The initial results are presented here.

Several different spare modules of the D0 experiment Silicon Microstrip Tracker (SMT) have been irradiated at the Fermilab Booster Radiation Damage Facility (RDF). The total dose received was 2.1 MRads with a proton flux of {approx} 3 {center_dot} 10{sup 11} p/cm{sup 2} sec. The irradiation was carried out in steps of 0.3 or 0.6 MRad, with several days between the steps to allow for annealing and measurements. The leakage currents and depletion voltages of the devices increased with dose, as expected from bulk radiation damage. The double sided, double metal devices showed worse degradation than the less complex detectors.

The Silicon Photomultiplier (SiPM) is a novel photodetector being developed for high energy physics applications. SiPM is attractive for PET imaging because it is compact; provides high gain at low voltage; is insensitive to magnetic fields; has a fast timing response; and is potentially inexpensive and CMOS-technology compatible. Researchers have characterized SiPM performance mostly in areas relevant to high-energy physics and astrophysics applications, with some findings demonstrating the potential usefulness of SiPM in positron emission tomography (PET) imaging. Using our photodetector characterization test-stand equipped with a 20 GSps sample rate and 6 GHz bandwidth oscilloscope, we have measured the gains in the range of 1-3 times 105 room temperature for SiPM samples obtained from different producers. We have measured the rising times and their standard deviations. Based on the measured dark-count rates at room temperature, we have also estimated the achievable energy resolution of SiPM in PET imaging when used with LSO and BGO scintillators.

An extrusion line has been installed and successfully operated at FNAL (Fermi National Accelerator Laboratory) in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new Facility will serve to further develop and improve extruded plastic scintillator. Recently progress has been made in producing co‐extruded plastic scintillator, thus increasing the potential HEP applications of this Facility. The current R&D work with extruded and co‐extruded plastic scintillator for a potential ALICE upgrade, the ILC calorimetry program and the MINERvA experiment show the attractiveness of the chosen strategy for future experiments and calorimetry. We extensively discuss extruded and co‐extruded plastic scintillator in calorimetry in synergy with new Solid State Photomultipliers. The characteristics of extruded and co‐extruded plastic scintillator will be presented here as well as results with non‐traditional photo read‐out.

In this article we show the latest results on the characteristics of the MRS (metal/resistor/semiconductor) photodiode. They include measurements of noise vs. threshold characteristics, noise frequency and signal amplitude dependence on the applied voltage and temperature and irradiation dose, and stability as a function of time. The photoelectron separation for this sensor is measured using a signal from a light emitting diode (LED). The response of the photodetector to light from the extruded 5 mm thick long strips of scintillator is studied using cosmic ray muons. Also, fiber-sensor alignment effects were studied. The results are promising and illustrate the potential use of MRS as photosensors in wide range of detectors.

The experimental results on the performance of the extruded scintillator and WLS fiber, and various LEDs in the magnetic fields of 1.8T and 2.3T respectively, are reported. The methodic used is being described.

We present the results of final acceptance tests of the DELPHI VFT ministrip detector before and during detector assembly. Dedicated tests were carried out to detect substandard channels, measure the S N performance and test the assembled detector for electronic failures.

The experimental results on the performance of the MRS (Metal/Resistor/Semiconductor) photodiode in the strong magnetic field of 4.4T, and the possible impact of the quench of the magnet at 4.5T on sensor's operation are reported.

The current conceptual design of proposed Large EMCal of ALICE at LHC is based largely on the scintillating mega-tile/fiber technology implemented in CDF Endplug upgrade project and in both barrel and endcap electromagnetic calorimeters of the STAR. The cost of scintillating material leads us to the choice of extruded polystyrene based scintillator, which is available in new FNAL-NICADD facility. Result of optical measurements, such as light yield and light yield variation, show that it is possible to use this material as active media of Large EMCal of ALICE at LHC., Comment: 6 pages, 5 figures,Prepared for XIth International Conference on Calorimetry in High Energy Physics (Calor 2004), Perugia, Italy, March 29 - April 2, 2004

Hadron calorimeter will play a key role in the success of a future e+e Linear Collider Detector (LCD). The hadron calorimeter should provide excellent energy resolution (30%E) for jets, and a fine degree of segmentation. As a possible solution, we propose the use of a Scintillating Digital Hadron Calorimeter (SDHC), which consists of millions of small plastic scintillating cells. Wave Length Shifting (WLS) fibers, embedded in the cells, will be used in the readout system. The results of studies for cell shape and thickness, shape and depth of groove for the embedded fiber, and coating materials are reported. In a cosmic-ray test, 5 mm thick cells made from BC408 scintillating plastic with WLS BCF92 1 mm outer diameter fiber, provided 30 photo-electrons measured with a 80% quantum efficiency photo-cathode.

An understanding of the costs involved in the production of plastic scintillators and the development of a less expensive material have become necessary with the prospects of building very large plastic scintillation detectors. Several factors contribute to the high cost of plastic scintillating sheets, but the principal reason is the labor-intensive nature of the manufacturing process. In order to significantly lower the costs, the current casting procedures had to be abandoned. Since polystyrene is widely used in the consumer industry, the logical path was to investigate the extrusion of commercial-grade polystyrene pellets with dopants to yield high quality plastic scintillator. This concept was tested and high quality extruded plastic scintillator was produced. The DO and MINOS experiments are already using extruded scintillator strips in their detectors. An extrusion line has recently been installed at Fermilab in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new facility will serve to further develop and improve extruded plastic scintillator. This paper will discuss the characteristics of extruded plastic scintillator and its raw materials, the different manufacturing techniques and the current R&D program at Fermilab.

Shashlik calorimeter prototypes equipped with preshower detector have been tested in 3 T magnetic field with electron beam at CERN-SPS. The signal from electrons increases as much as 11% at 3 T magnetic field. No significant deterioration on the energy resolution as well as the preshower detector performance have been observed.