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Nikolaos Tsapatsaris - One of the best experts on this subject based on the ideXlab platform.
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parasitic neutron beam monitoring proof of concept on Gamma monitoring of neutron chopper phases
EPL, 2020Co-Authors: F Issa, R Hallwilton, A Quintanilla, M Olsson, D Zielinski, K Kanaki, Nikolaos TsapatsarisAbstract:Neutron beam monitors are an essential diagnostic component of neutron scattering facilities. They are used to measure neutron flux, calibrating experiments performed on the instruments, allowing measurement of facility performance, understanding of the effect on the neutrons of beam-line components (such as choppers), calibration of Detectors and tracking of beam stability. Ideally beam monitors should not perturb the beam. Previous work shows commercial beam monitors attenuate the beam by a few percent in the worst case due to the 1–2 mm thick aluminium entrance and exit windows and the material inside. Parasitic methods of neutron beam diagnostics, where there is no beam monitor directly in the beam, would be preferable. This paper presents the concept of a parasitic method of monitoring the beam which can be used for neutron chopper phasing. This is achieved by placing a Gamma Detector close to a rotating chopper and measuring a signal proportional to the flux absorbed by the chopper. Neutrons interact with the boron absorber on the chopper disc leading to Gamma emission at 480 keV. Detection of these Gamma rays is used to determine the chopper phasing and timing. Potentially information on the flux of the beamline can be extracted. Results from a proof of concept implementation show that diagnosis of neutron chopper phases is feasible.
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parasitic neutron beam monitoring proof of concept on Gamma monitoring of neutron chopper phases
arXiv: Instrumentation and Detectors, 2020Co-Authors: F Issa, R Hallwilton, A Quintanilla, M Olsson, D Zielinski, K Kanaki, Nikolaos TsapatsarisAbstract:Neutron beam monitors are an essential diagnostic component of neutron scattering facilities. They are used to measure neutron flux, calibrating experiments performed on the instruments, allowing measurement of facility performance, understanding of the effect on the neutrons of beam-line components (such as choppers), calibration of Detectors and tracking of beam stability. Ideally beam monitors {should} not perturb the beam. Previous work shows commercial beam monitors attenuate the beam by a few percent in the worst case due to the 1-2 mm thick Aluminium entrance and exit windows and the material inside. Parasitic methods of neutron beam diagnostics, where there is no beam monitor directly in the beam, would be preferable. This paper presents the concept of a parasitic method of monitoring the beam which can be used for neutron chopper phasing. This is achieved by placing a Gamma Detector close to a rotating chopper and measures a signal proportional to the flux absorbed by the chopper. Neutrons interact with the Boron absorber on the chopper disc lead to Gamma emission at 480 keV. Detection of these Gamma rays is used to determine the chopper phasing and timing. Potentially information on the flux of the beamline can be extracted. Results from a proof of concept implementation show that diagnosis of neutron chopper phases is feasible.
R Hallwilton - One of the best experts on this subject based on the ideXlab platform.
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parasitic neutron beam monitoring proof of concept on Gamma monitoring of neutron chopper phases
EPL, 2020Co-Authors: F Issa, R Hallwilton, A Quintanilla, M Olsson, D Zielinski, K Kanaki, Nikolaos TsapatsarisAbstract:Neutron beam monitors are an essential diagnostic component of neutron scattering facilities. They are used to measure neutron flux, calibrating experiments performed on the instruments, allowing measurement of facility performance, understanding of the effect on the neutrons of beam-line components (such as choppers), calibration of Detectors and tracking of beam stability. Ideally beam monitors should not perturb the beam. Previous work shows commercial beam monitors attenuate the beam by a few percent in the worst case due to the 1–2 mm thick aluminium entrance and exit windows and the material inside. Parasitic methods of neutron beam diagnostics, where there is no beam monitor directly in the beam, would be preferable. This paper presents the concept of a parasitic method of monitoring the beam which can be used for neutron chopper phasing. This is achieved by placing a Gamma Detector close to a rotating chopper and measuring a signal proportional to the flux absorbed by the chopper. Neutrons interact with the boron absorber on the chopper disc leading to Gamma emission at 480 keV. Detection of these Gamma rays is used to determine the chopper phasing and timing. Potentially information on the flux of the beamline can be extracted. Results from a proof of concept implementation show that diagnosis of neutron chopper phases is feasible.
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parasitic neutron beam monitoring proof of concept on Gamma monitoring of neutron chopper phases
arXiv: Instrumentation and Detectors, 2020Co-Authors: F Issa, R Hallwilton, A Quintanilla, M Olsson, D Zielinski, K Kanaki, Nikolaos TsapatsarisAbstract:Neutron beam monitors are an essential diagnostic component of neutron scattering facilities. They are used to measure neutron flux, calibrating experiments performed on the instruments, allowing measurement of facility performance, understanding of the effect on the neutrons of beam-line components (such as choppers), calibration of Detectors and tracking of beam stability. Ideally beam monitors {should} not perturb the beam. Previous work shows commercial beam monitors attenuate the beam by a few percent in the worst case due to the 1-2 mm thick Aluminium entrance and exit windows and the material inside. Parasitic methods of neutron beam diagnostics, where there is no beam monitor directly in the beam, would be preferable. This paper presents the concept of a parasitic method of monitoring the beam which can be used for neutron chopper phasing. This is achieved by placing a Gamma Detector close to a rotating chopper and measures a signal proportional to the flux absorbed by the chopper. Neutrons interact with the Boron absorber on the chopper disc lead to Gamma emission at 480 keV. Detection of these Gamma rays is used to determine the chopper phasing and timing. Potentially information on the flux of the beamline can be extracted. Results from a proof of concept implementation show that diagnosis of neutron chopper phases is feasible.
F Issa - One of the best experts on this subject based on the ideXlab platform.
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parasitic neutron beam monitoring proof of concept on Gamma monitoring of neutron chopper phases
EPL, 2020Co-Authors: F Issa, R Hallwilton, A Quintanilla, M Olsson, D Zielinski, K Kanaki, Nikolaos TsapatsarisAbstract:Neutron beam monitors are an essential diagnostic component of neutron scattering facilities. They are used to measure neutron flux, calibrating experiments performed on the instruments, allowing measurement of facility performance, understanding of the effect on the neutrons of beam-line components (such as choppers), calibration of Detectors and tracking of beam stability. Ideally beam monitors should not perturb the beam. Previous work shows commercial beam monitors attenuate the beam by a few percent in the worst case due to the 1–2 mm thick aluminium entrance and exit windows and the material inside. Parasitic methods of neutron beam diagnostics, where there is no beam monitor directly in the beam, would be preferable. This paper presents the concept of a parasitic method of monitoring the beam which can be used for neutron chopper phasing. This is achieved by placing a Gamma Detector close to a rotating chopper and measuring a signal proportional to the flux absorbed by the chopper. Neutrons interact with the boron absorber on the chopper disc leading to Gamma emission at 480 keV. Detection of these Gamma rays is used to determine the chopper phasing and timing. Potentially information on the flux of the beamline can be extracted. Results from a proof of concept implementation show that diagnosis of neutron chopper phases is feasible.
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parasitic neutron beam monitoring proof of concept on Gamma monitoring of neutron chopper phases
arXiv: Instrumentation and Detectors, 2020Co-Authors: F Issa, R Hallwilton, A Quintanilla, M Olsson, D Zielinski, K Kanaki, Nikolaos TsapatsarisAbstract:Neutron beam monitors are an essential diagnostic component of neutron scattering facilities. They are used to measure neutron flux, calibrating experiments performed on the instruments, allowing measurement of facility performance, understanding of the effect on the neutrons of beam-line components (such as choppers), calibration of Detectors and tracking of beam stability. Ideally beam monitors {should} not perturb the beam. Previous work shows commercial beam monitors attenuate the beam by a few percent in the worst case due to the 1-2 mm thick Aluminium entrance and exit windows and the material inside. Parasitic methods of neutron beam diagnostics, where there is no beam monitor directly in the beam, would be preferable. This paper presents the concept of a parasitic method of monitoring the beam which can be used for neutron chopper phasing. This is achieved by placing a Gamma Detector close to a rotating chopper and measures a signal proportional to the flux absorbed by the chopper. Neutrons interact with the Boron absorber on the chopper disc lead to Gamma emission at 480 keV. Detection of these Gamma rays is used to determine the chopper phasing and timing. Potentially information on the flux of the beamline can be extracted. Results from a proof of concept implementation show that diagnosis of neutron chopper phases is feasible.
C Fiorini - One of the best experts on this subject based on the ideXlab platform.
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spectroscopic performance of a sr co doped 3 labr3 scintillator read by a sipm array
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2019Co-Authors: G L Montagnani, C Fiorini, F Camera, L Buonanno, Davide Di Vita, Marco Carminati, A Gola, V RegazzoniAbstract:Abstract LaBr3:Ce crystals represent a key element for high-resolution Gamma-ray Detectors based on indirect conversion. Recent developments in crystal technologies have brought to the market Sr2+ co-doped 3” scintillators with a light yield 28% higher than standard LaBr3 crystals. Concurrently, high-density silicon photo-multipliers (SiPMs) have enabled the possibility of solid-state readout of these crystals, providing state-of-the-art energy resolution and wide dynamic range. In order to assess the performance of a solid-state readout of a large LaBr crystal, we developed a low-noise readout instrument based on a 12 × 12 array of 6 mm × 6 mm NUV-HD SiPMs produced by FBK. The array of photo-Detectors was coupled to a custom-developed 8-channel ASIC with automatic gain switching named Gamma. Detector biasing, data acquisition, processing and transfer are performed by a compact microcontroller-based unit. The resulting instrument was tested with two different crystals: a standard 3”LaBr3:Ce3+ and the Sr2+ co-doped version. Thanks to the low-noise performance of SiPMs and of the electronics it has been possible to investigate the ultimate noise performance of the crystal and compare the results between the two crystals. A 3.4% FWHM energy resolution at the 137Cs 662 keV photopeak was measured with the standard LaBr3 crystal, while it improved to 2.6% at 662 keV with the co-doped crystal. Beyond presenting the unprecedented spectroscopic performance of the 3” co-doped crystal, this work is a further demonstration of the SiPM consolidating technology suitability to replace photo-multiplier tubes (PMT) for demanding applications in nuclear physics and astrophysics.
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development of a Detector for Gamma ray spectroscopy based on silicon drift Detector arrays and 2 prime prime lanthanum bromide scintillator
IEEE Transactions on Nuclear Science, 2015Co-Authors: A D Butt, R Quaglia, C Fiorini, P Busca, M Occhipinti, G Giacomini, C Piemonte, F Camera, Nick Nelms, Brian ShorttAbstract:This work describes the development of a Gamma Detector based on silicon drift Detectors (SDDs) to read out large ${\hbox{LaBr}}_3$ : ${\hbox{Ce}}$ scintillators for Gamma-ray astronomy applications, within an activity supported by the European Space Agency (ESA). SDDs, characterized by high quantum efficiency and low electronic noise, when coupled with a scintillator are good candidates for Gamma-ray spectroscopy applications in a wide energy range, e.g., from 150 keV to 15 MeV. The Gamma-ray Detector prototype presented here is composed of a 2 ${^\prime}{^\prime}$ $\times$ 2 ${^\prime}{^\prime}$ ${\hbox{LaBr}}_3$ : ${\hbox{Ce}}$ scintillator coupled with four SDD arrays arranged in a $2 \times 2$ format (a total of 36 SDDs). This detection system is operated with custom readout application specific integrated circuits (ASICs) and a data acquisition (DAQ) system. With this prototype Gamma-camera, an energy resolution of 3.4% FWHM at 662 keV has been measured. Spectroscopy measurements have been carried out between 300 keV and 1800 keV and the achieved results are consistent with the electronic noise of the SDD technology. In this work, we report on the SDD based detection head’s design, its X-ray characterization, readout electronics, experimental setups and Gamma-ray spectroscopy results. Finally, perspectives with the possible use of an improved SDD technology are discussed.
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Prompt Gamma imaging with a slit camera for real-time range control in proton therapy
Physics in Medicine and Biology, 2012Co-Authors: J. Smeets, C Fiorini, P Busca, F. Roellinghoff, D. Prieels, F. Stichelbaut, A. Benilov, R. Peloso, M. Basilavecchia, T. FrizziAbstract:Treatments delivered by proton therapy are affected by uncertainties on the range of the beam within the patient, requiring medical physicists to add safety margins on the penetration depth of the beam. To reduce these margins and deliver safer treatments, different projects are currently investigating real-time range control by imaging prompt Gammas emitted along the proton tracks in the patient. This study reports on the feasibility, development and test of a new concept of prompt Gamma camera using a slit collimator to obtain a one-dimensional projection of the beam path on a scintillation Detector. This concept was optimized, using the Monte Carlo code MCNPX version 2.5.0, to select high energy photons correlated with the beam range and detect them with both high statistics and sufficient spatial resolution. To validate the Monte Carlo model, spectrometry measurements of secondary particles emitted by a PMMA target during proton irradiation at 160 MeV were realized. An excellent agreement with the simulations was observed when using subtraction methods to isolate the Gammas in direct incidence. A first prototype slit camera using the HiCam Gamma Detector was consequently prepared and tested successfully at 100 and 160 MeV beam energies. Results confirmed the potential of this concept for real-time range monitoring with millimetre accuracy in pencil beam scanning mode for typical clinical conditions. If we neglect electronic dead times and rejection of detected events, the current solution with its collimator at 15 cm from the beam axis can achieve a 1-2 mm standard deviation on range estimation in a homogeneous PMMA target for numbers of protons that correspond to doses in water at the Bragg peak as low as 15 cGy at 100 MeV and 25 cGy at 160 MeV assuming pencil beams with a Gaussian profile of 5 mm sigma at target entrance.
A Tursucu - One of the best experts on this subject based on the ideXlab platform.
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measurement of the effective atomic number of fexcr1 x and fexnix alloys using scattering of Gamma rays
Journal of Alloys and Compounds, 2013Co-Authors: D Demir, A TursucuAbstract:In the present work, to determine the effective atomic number of alloys such as Fe0.5Cr0.5, Fe0.7Cr0.3, Fe0.8Cr0.2, Fe0.9Cr0.1, Fe0.2Ni0.8, Fe0.3Ni0.7, Fe0.5Ni0.5, Fe0.6Ni0.4, Fe0.7Ni0.3 and Fe0.8Ni0.2 the scattering of 59.54 keV Gamma rays is studied using a high-resolution HPGe Detector with a resolution of 182 eV at 5.9 keV and placed at 167o. The experiment is performed on various elements with atomic number satisfying, 4 ⩽ Z ⩽ 82, for 59.54 keV Gamma rays from a 5 Ci 241Am annular radioactive source. The intensity ratio of Rayleigh to Compton scattered peaks, corrected for photo-peak efficiency of Gamma Detector and absorption of photons in the sample and air, is plotted as function of atomic number and constituted a best fit-curve. From this fit-curve, the respective effective atomic numbers to samples of alloys are determined. Also, the effective atomic numbers of alloys have been calculated by using the theoretical mass attenuation coefficients. The agreement of measured values of effective atomic numbers with theoretical calculations is quite satisfactory.
