Pub Date : 2023-10-01DOI: 10.1088/1748-0221/18/10/c10017
Seungjun Yoo, Hubeom Shin, Seokwon Oh, Junho Lee, Hunhee Kim, Ho Kyung Kim
Abstract We investigated the detective quantum efficiency (DQE) of thin gadolinium oxysulfide phosphor-based flat-panel detectors (FPDs) using cascaded-systems analysis and Monte Carlo (MC) simulations for applications in megavoltage (MV) x-ray industrial imaging. We decomposed the DQE formula into (dose-independent) upper-limit DQE and (dose-dependent) DQE-reduction factors. We obtained the absorbed energy distributions (AEDs) for various x-ray detector designs and photon energies using MC simulations and applied the AED analysis to the DQE formula. The investigations examined include the x-ray-detector-only DQE and the effect of the coupling efficiency between the x-ray detector and readout panel, including electronic noise, on the upper-limit DQE. This study confirms that the design of the metal build-up layer on the phosphor is effective for MV imaging and emphasizes the importance of designing the readout panel to maintain the upper-limit DQE. We expect the proposed DQE analysis to be suitable for designing and evaluating FPDs for high-energy nondestructive x-ray testing.
{"title":"Analysis of absorption signal and noise in thin phosphor detectors for high-energy transmission radiography","authors":"Seungjun Yoo, Hubeom Shin, Seokwon Oh, Junho Lee, Hunhee Kim, Ho Kyung Kim","doi":"10.1088/1748-0221/18/10/c10017","DOIUrl":"https://doi.org/10.1088/1748-0221/18/10/c10017","url":null,"abstract":"Abstract We investigated the detective quantum efficiency (DQE) of thin gadolinium oxysulfide phosphor-based flat-panel detectors (FPDs) using cascaded-systems analysis and Monte Carlo (MC) simulations for applications in megavoltage (MV) x-ray industrial imaging. We decomposed the DQE formula into (dose-independent) upper-limit DQE and (dose-dependent) DQE-reduction factors. We obtained the absorbed energy distributions (AEDs) for various x-ray detector designs and photon energies using MC simulations and applied the AED analysis to the DQE formula. The investigations examined include the x-ray-detector-only DQE and the effect of the coupling efficiency between the x-ray detector and readout panel, including electronic noise, on the upper-limit DQE. This study confirms that the design of the metal build-up layer on the phosphor is effective for MV imaging and emphasizes the importance of designing the readout panel to maintain the upper-limit DQE. We expect the proposed DQE analysis to be suitable for designing and evaluating FPDs for high-energy nondestructive x-ray testing.","PeriodicalId":16184,"journal":{"name":"Journal of Instrumentation","volume":"121 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136054524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.1088/1748-0221/18/10/p10026
O. Smirnov
Abstract Fluctuations in photon production in scintillator could contribute to the total energy resolution of a scintillation detector. This contribution, called intrinsic resolution (IR), is one of the factors limiting the total energy resolution in detectors based on liquid organic scintillators (LSs). There are very few experimental measurements of the IR in LSs available, and the underlying physics is not completely understood. We propose a phenomenological description of IR of LSs and systematize the data available using a single universal parameter that characterizes IR. We show that all experimental data within the model demonstrate the presence of extra smearing of energy resolution due to IR with a typical value of ≃ 2% at 1-MeV energy release. The model can be used to simulate the effect of IR in LS-based detectors.
{"title":"Note on intrinsic resolution in liquid organic scintillators","authors":"O. Smirnov","doi":"10.1088/1748-0221/18/10/p10026","DOIUrl":"https://doi.org/10.1088/1748-0221/18/10/p10026","url":null,"abstract":"Abstract Fluctuations in photon production in scintillator could contribute to the total energy resolution of a scintillation detector. This contribution, called intrinsic resolution (IR), is one of the factors limiting the total energy resolution in detectors based on liquid organic scintillators (LSs). There are very few experimental measurements of the IR in LSs available, and the underlying physics is not completely understood. We propose a phenomenological description of IR of LSs and systematize the data available using a single universal parameter that characterizes IR. We show that all experimental data within the model demonstrate the presence of extra smearing of energy resolution due to IR with a typical value of ≃ 2% at 1-MeV energy release. The model can be used to simulate the effect of IR in LS-based detectors.","PeriodicalId":16184,"journal":{"name":"Journal of Instrumentation","volume":"207 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136059532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In an ion implanter, plasma flood gun (PFG) is used to provide electrons to neutralize the accumulated charge on the wafer surface to avoid breakdown damage. With the development of ion implantation technology, four key requirements have been put forward for PFG. They are simple structure, plasma with high density and low electron temperature, no metal contamination and long life. The existing PFG, such as the filament type PFG, can hardly meet the above requirements at the same time. 2.45 GHz ECR ion source with the advantages of high beam density, high stability, long life time and no filament metal contamination, has shown great potential to work as PFG. Recently, a miniaturized 2.45 GHz permanent magnet electron cyclotron resonance PFG (PMECR-PFG) has been developed at Peking University (PKU). In our previous test, 8.8 mA electron extraction current was obtained with argon gas. In this work, by optimizing the magnetic field configuration to a resonant configuration, the performance of this ECR-PFG was greatly improved. With 100 W microwave power, an 80 mA electron current load was obtained under the extraction voltage of 0.1 kV. To minimize the metal contamination, a three-slit graphite plasma electrode was fabricated and a 50 mA load was generated at only 30 W RF power. During all tests, the gas consumption rate is lower than 0.6 sccm, which is beneficial to maintain the vacuum of implanter beamline.
{"title":"Improvement of miniaturized 2.45 GHz ECR plasma flood gun at PKU","authors":"Bujian Cui, Shixiang Peng, Wenbin Wu, Tenghao Ma, Yaoxiang Jiang, Zhiyu Guo, Jiaer Chen","doi":"10.1088/1748-0221/18/10/p10038","DOIUrl":"https://doi.org/10.1088/1748-0221/18/10/p10038","url":null,"abstract":"Abstract In an ion implanter, plasma flood gun (PFG) is used to provide electrons to neutralize the accumulated charge on the wafer surface to avoid breakdown damage. With the development of ion implantation technology, four key requirements have been put forward for PFG. They are simple structure, plasma with high density and low electron temperature, no metal contamination and long life. The existing PFG, such as the filament type PFG, can hardly meet the above requirements at the same time. 2.45 GHz ECR ion source with the advantages of high beam density, high stability, long life time and no filament metal contamination, has shown great potential to work as PFG. Recently, a miniaturized 2.45 GHz permanent magnet electron cyclotron resonance PFG (PMECR-PFG) has been developed at Peking University (PKU). In our previous test, 8.8 mA electron extraction current was obtained with argon gas. In this work, by optimizing the magnetic field configuration to a resonant configuration, the performance of this ECR-PFG was greatly improved. With 100 W microwave power, an 80 mA electron current load was obtained under the extraction voltage of 0.1 kV. To minimize the metal contamination, a three-slit graphite plasma electrode was fabricated and a 50 mA load was generated at only 30 W RF power. During all tests, the gas consumption rate is lower than 0.6 sccm, which is beneficial to maintain the vacuum of implanter beamline.","PeriodicalId":16184,"journal":{"name":"Journal of Instrumentation","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136153716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.1088/1748-0221/18/10/p10006
S.M. Mazza, G. Saito, Y. Zhao, T. Kirkes, N. Yoho, D. Yerdea, N. Nagel, J. Ott, M. Nizam, M. Leite, M. Moralles, H.F.-W. Sadrozinski, A. Seiden, B. Schumm, F. McKinney-Martinez, G. Giacomini, W. Chen
Abstract Low Gain Avalanche Diodes (LGADs) represent the state-of-the-art in timing measurements and will instrument the future Timing Detectors of ATLAS and CMS for the High-Luminosity LHC. While initially conceived as a sensor for charged particles, the intrinsic gain of LGADs makes it possible to detect low-energy X-rays with good energy resolution and excellent time resolution (tens of picoseconds). Using the Stanford Synchrotron Radiation Lightsource (SSRL) at SLAC, several LGADs designs were characterized with energies from 5 to 70 keV. The SSRL provides 10 ps pulsed X-ray bunches separated by 2 ns intervals with an energy dispersion (Δ E / E ) of 10 -4 . LGADs from Hamamatsu Photonics (HPK) and Brookhaven National Laboratory (BNL) with different thicknesses ranging from 20 μm to 50 μm and different gain layer designs were read out using fast amplification boards and digitized with a high bandwidth and high sampling rate oscilloscope. PIN devices from HPK and AC-LGADs from BNL were characterized as well. A systematic and detailed characterization of the devices' energy linearity, resolution, and time resolution as a function of X-ray energy was performed for different biasing voltages at room temperature and are reported in this work. The charge collection and multiplication mechanism were simulated using Geant4 and TCAD Sentaurus, providing an important handle for interpreting the data.
{"title":"Synchrotron light source X-ray detection with Low-Gain Avalanche Diodes","authors":"S.M. Mazza, G. Saito, Y. Zhao, T. Kirkes, N. Yoho, D. Yerdea, N. Nagel, J. Ott, M. Nizam, M. Leite, M. Moralles, H.F.-W. Sadrozinski, A. Seiden, B. Schumm, F. McKinney-Martinez, G. Giacomini, W. Chen","doi":"10.1088/1748-0221/18/10/p10006","DOIUrl":"https://doi.org/10.1088/1748-0221/18/10/p10006","url":null,"abstract":"Abstract Low Gain Avalanche Diodes (LGADs) represent the state-of-the-art in timing measurements and will instrument the future Timing Detectors of ATLAS and CMS for the High-Luminosity LHC. While initially conceived as a sensor for charged particles, the intrinsic gain of LGADs makes it possible to detect low-energy X-rays with good energy resolution and excellent time resolution (tens of picoseconds). Using the Stanford Synchrotron Radiation Lightsource (SSRL) at SLAC, several LGADs designs were characterized with energies from 5 to 70 keV. The SSRL provides 10 ps pulsed X-ray bunches separated by 2 ns intervals with an energy dispersion (Δ E / E ) of 10 -4 . LGADs from Hamamatsu Photonics (HPK) and Brookhaven National Laboratory (BNL) with different thicknesses ranging from 20 μm to 50 μm and different gain layer designs were read out using fast amplification boards and digitized with a high bandwidth and high sampling rate oscilloscope. PIN devices from HPK and AC-LGADs from BNL were characterized as well. A systematic and detailed characterization of the devices' energy linearity, resolution, and time resolution as a function of X-ray energy was performed for different biasing voltages at room temperature and are reported in this work. The charge collection and multiplication mechanism were simulated using Geant4 and TCAD Sentaurus, providing an important handle for interpreting the data.","PeriodicalId":16184,"journal":{"name":"Journal of Instrumentation","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134935909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.1088/1748-0221/18/10/t10001
R. Bouet, J. Busto, V. Cecchini, C. Cerna, P. Charpentier, M. Chapellier, A. Dastgheibi-Fard, F. Druillole, C. Jollet, P. Hellmuth, M. Gros, P. Lautridou, A. Meregaglia, X.F. Navick, F. Piquemal, F. Popieul, M. Roche, I. Savvidis, B. Thomas
Abstract Radial time projection chambers (TPC), already employed in the search for rare phenomena such as light Dark Matter candidate, could provide a new detection approach for the search of neutrinoless double beta decay ( ββ 0 ν ). The assessment of the performances of such a detector for ββ 0 ν search is indeed the goal of the Rare Decays with Radial Detector (R2D2) R&D. Promising results operating a spherical TPC with argon up to 1 bar have been published in 2021. Supplementary measurements were recently taken extending the gas pressure range up to 3 bar. In addition, a comparison between two detector geometries, namely spherical (SPC for spherical proportional counter) and cylindrical (CPC for cylindrical proportional counter), was performed. Using a relatively simple gas purification system the CPC detector was also operated with xenon at 1 bar: an energy resolution of 1.4% full-width at half-maximum was achieved for drift distances up to 17 cm. Much lower resolution was observed with the SPC. These results are presented in this article.
{"title":"R2D2 TPC: first Xenon results","authors":"R. Bouet, J. Busto, V. Cecchini, C. Cerna, P. Charpentier, M. Chapellier, A. Dastgheibi-Fard, F. Druillole, C. Jollet, P. Hellmuth, M. Gros, P. Lautridou, A. Meregaglia, X.F. Navick, F. Piquemal, F. Popieul, M. Roche, I. Savvidis, B. Thomas","doi":"10.1088/1748-0221/18/10/t10001","DOIUrl":"https://doi.org/10.1088/1748-0221/18/10/t10001","url":null,"abstract":"Abstract Radial time projection chambers (TPC), already employed in the search for rare phenomena such as light Dark Matter candidate, could provide a new detection approach for the search of neutrinoless double beta decay ( ββ 0 ν ). The assessment of the performances of such a detector for ββ 0 ν search is indeed the goal of the Rare Decays with Radial Detector (R2D2) R&D. Promising results operating a spherical TPC with argon up to 1 bar have been published in 2021. Supplementary measurements were recently taken extending the gas pressure range up to 3 bar. In addition, a comparison between two detector geometries, namely spherical (SPC for spherical proportional counter) and cylindrical (CPC for cylindrical proportional counter), was performed. Using a relatively simple gas purification system the CPC detector was also operated with xenon at 1 bar: an energy resolution of 1.4% full-width at half-maximum was achieved for drift distances up to 17 cm. Much lower resolution was observed with the SPC. These results are presented in this article.","PeriodicalId":16184,"journal":{"name":"Journal of Instrumentation","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135459373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.1088/1748-0221/18/10/p10020
E. Currás Rivera, A. La Rosa, M. Moll, F. Zareef
Abstract The high-luminosity upgrade of the ATLAS and CMS experiments includes dedicated sub-detectors to perform the time-stamping of minimum ionizing particles (MIPs). These detectors will be exposed up to fluences in the range of 1.5-2.5 × 10 15 n eq /cm 2 at the end of their lifetime and, Low Gain Avalanche Diode (LGAD) has been chosen as their baseline detection technology. To better understand the performance of LGAD detectors in these environments, a gain layer degradation study after neutron and proton irradiations up to a fluence of 1.5 × 10 15 n eq /cm 2 was performed. LGADs manufactured at Hamamatsu Photonics (HPK) and Centro Nacional de Microelectrónica (CNM-IMB) were chosen for this study and, a comparison in the gain layer degradation after exposure to reactor neutrons at the Jožef Stefan Institute (JSI) in Ljubjana and 24 GeV/c protons at the CERN-PS is presented here.
ATLAS和CMS实验的高亮度升级包括专用子探测器来执行最小电离粒子(MIPs)的时间戳。这些探测器将暴露在1.5-2.5 × 10 15 n eq / cm2的影响范围内，在其寿命结束时，低增益雪崩二极管(LGAD)已被选择作为其基线检测技术。为了更好地了解LGAD探测器在这些环境中的性能，进行了中子和质子辐照后增益层退化的研究，辐照的影响可达1.5 × 10 15 n eq / cm2。本研究选择了滨松光子(HPK)和国家中心Microelectrónica (CNM-IMB)制造的LGADs，并比较了在卢比雅那Jožef Stefan研究所(JSI)的反应堆中子和在CERN-PS的24 GeV/c质子照射后的增益层退化情况。
{"title":"Gain layer degradation study after neutron and proton irradiations in Low Gain Avalanche Diodes","authors":"E. Currás Rivera, A. La Rosa, M. Moll, F. Zareef","doi":"10.1088/1748-0221/18/10/p10020","DOIUrl":"https://doi.org/10.1088/1748-0221/18/10/p10020","url":null,"abstract":"Abstract The high-luminosity upgrade of the ATLAS and CMS experiments includes dedicated sub-detectors to perform the time-stamping of minimum ionizing particles (MIPs). These detectors will be exposed up to fluences in the range of 1.5-2.5 × 10 15 n eq /cm 2 at the end of their lifetime and, Low Gain Avalanche Diode (LGAD) has been chosen as their baseline detection technology. To better understand the performance of LGAD detectors in these environments, a gain layer degradation study after neutron and proton irradiations up to a fluence of 1.5 × 10 15 n eq /cm 2 was performed. LGADs manufactured at Hamamatsu Photonics (HPK) and Centro Nacional de Microelectrónica (CNM-IMB) were chosen for this study and, a comparison in the gain layer degradation after exposure to reactor neutrons at the Jožef Stefan Institute (JSI) in Ljubjana and 24 GeV/c protons at the CERN-PS is presented here.","PeriodicalId":16184,"journal":{"name":"Journal of Instrumentation","volume":"147 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135849817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.1088/1748-0221/18/10/c10011
Anastasia Doinaki, Ciro Calzolaio, Ritwika Chakraborty, Michal Duda, Chavdar Dutsov, Massimo Giovannozzi, Timothy Hume, Katia Michielsen, Ljiljana Morvaj, Angela Papa, Philipp Schmidt-Wellenburg, David Stäger, Bastiano Vitali
Abstract At the Paul Scherrer Institute (PSI), we are setting up an experiment to search for the electric dipole moment (EDM) of the muon using the frozen-spin technique. The discovery of a muon EDM would indicate violation of charge conjugation parity symmetry (CP-violation) and lepton flavor universality, beyond the Standard Model. The experiment aims to achieve a sensitivity of σ ( d μ ) ≤ 6 × 10 -23 e · cm. This study is taking place during the first phase of the experiment and it focuses on the off-axis injection of muons into a 3 T storage solenoid. Muons need to be transported from the exit of the PSI beamline, a low magnetic-field region, into the strong magnetic-field of the solenoid. For this purpose, two magnetically shielded channels are being developed. In the direct vicinity of the injection helix inside the solenoid bore, we will use superconducting (SC) shielding to avoid any hysteresis effect, while farther away in the fringe field we will use iron tubes. Three prototypes of SC injection tubes will be produced: the first will use a commercial high temperature superconducting (HTS) tape wrapped around a hollow copper tube, the second will utilize several Nb-Ti/Nb/Cu sheets obtained from CERN, wrapped and mechanically clamped around another hollow copper tube, while the third will consist of a commercial cast Bi-2223 superconducting tube coiled with HTS tape. To evaluate the effectiveness of the different SC-shields, we will measure their shielding factors and determine the muon injection efficiency from the beamline into the solenoid.
{"title":"Superconducting shield for the injection channel of the muEDM experiment at PSI","authors":"Anastasia Doinaki, Ciro Calzolaio, Ritwika Chakraborty, Michal Duda, Chavdar Dutsov, Massimo Giovannozzi, Timothy Hume, Katia Michielsen, Ljiljana Morvaj, Angela Papa, Philipp Schmidt-Wellenburg, David Stäger, Bastiano Vitali","doi":"10.1088/1748-0221/18/10/c10011","DOIUrl":"https://doi.org/10.1088/1748-0221/18/10/c10011","url":null,"abstract":"Abstract At the Paul Scherrer Institute (PSI), we are setting up an experiment to search for the electric dipole moment (EDM) of the muon using the frozen-spin technique. The discovery of a muon EDM would indicate violation of charge conjugation parity symmetry (CP-violation) and lepton flavor universality, beyond the Standard Model. The experiment aims to achieve a sensitivity of σ ( d μ ) ≤ 6 × 10 -23 e · cm. This study is taking place during the first phase of the experiment and it focuses on the off-axis injection of muons into a 3 T storage solenoid. Muons need to be transported from the exit of the PSI beamline, a low magnetic-field region, into the strong magnetic-field of the solenoid. For this purpose, two magnetically shielded channels are being developed. In the direct vicinity of the injection helix inside the solenoid bore, we will use superconducting (SC) shielding to avoid any hysteresis effect, while farther away in the fringe field we will use iron tubes. Three prototypes of SC injection tubes will be produced: the first will use a commercial high temperature superconducting (HTS) tape wrapped around a hollow copper tube, the second will utilize several Nb-Ti/Nb/Cu sheets obtained from CERN, wrapped and mechanically clamped around another hollow copper tube, while the third will consist of a commercial cast Bi-2223 superconducting tube coiled with HTS tape. To evaluate the effectiveness of the different SC-shields, we will measure their shielding factors and determine the muon injection efficiency from the beamline into the solenoid.","PeriodicalId":16184,"journal":{"name":"Journal of Instrumentation","volume":"125 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135922378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.1088/1748-0221/18/10/p10030
I. Abt, C. Gooch, F. Hagemann, L. Hauertmann, D. Hervas Aguilar, X. Liu, O. Schulz, M. Schuster, A.J. Zsigmond
Abstract The electron drift in germanium detectors is modeled making many assumptions. Confronted with data, these assumptions have to be revisited. The temperature dependence of the drift of electrons was studied in detail for an n-type segmented point-contact germanium detector. The detector was mounted in a temperature controlled, electrically cooled cryostat. Surface events were induced with collimated 81 keV photons from a 133 Ba source. A detailed analysis of the rise time of pulses collected in surface scans, performed at different temperatures, is presented. The longitudinal anisotropy of the electron drift decreases with rising temperature. A new approach, making use of designated rise-time windows determined by simulations using SolidStateDetectors.jl , was used to isolate the longitudinal drift of electrons along different axes to quantify this observation. The measured temperature dependence of the longitudinal drift velocities combined with the standard electron-drift model as widely used in relevant simulation packages results in unphysical predictions. A modification of the electron-drift model based on assuming phonons to be the dominating scattering centers for electrons is motivated and described. The results of a first implementation of the modified model in SolidStateDetectors.jl are shown. They describe the temperature dependence of the data reasonably well. A general review of the model and the standard input values for mobilities is suggested.
{"title":"Temperature dependence of the electron-drift anisotropy and implications for the electron-drift model","authors":"I. Abt, C. Gooch, F. Hagemann, L. Hauertmann, D. Hervas Aguilar, X. Liu, O. Schulz, M. Schuster, A.J. Zsigmond","doi":"10.1088/1748-0221/18/10/p10030","DOIUrl":"https://doi.org/10.1088/1748-0221/18/10/p10030","url":null,"abstract":"Abstract The electron drift in germanium detectors is modeled making many assumptions. Confronted with data, these assumptions have to be revisited. The temperature dependence of the drift of electrons was studied in detail for an n-type segmented point-contact germanium detector. The detector was mounted in a temperature controlled, electrically cooled cryostat. Surface events were induced with collimated 81 keV photons from a 133 Ba source. A detailed analysis of the rise time of pulses collected in surface scans, performed at different temperatures, is presented. The longitudinal anisotropy of the electron drift decreases with rising temperature. A new approach, making use of designated rise-time windows determined by simulations using SolidStateDetectors.jl , was used to isolate the longitudinal drift of electrons along different axes to quantify this observation. The measured temperature dependence of the longitudinal drift velocities combined with the standard electron-drift model as widely used in relevant simulation packages results in unphysical predictions. A modification of the electron-drift model based on assuming phonons to be the dominating scattering centers for electrons is motivated and described. The results of a first implementation of the modified model in SolidStateDetectors.jl are shown. They describe the temperature dependence of the data reasonably well. A general review of the model and the standard input values for mobilities is suggested.","PeriodicalId":16184,"journal":{"name":"Journal of Instrumentation","volume":"247 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136093818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.1088/1748-0221/18/10/t10006
Sara Zarei, Farshad Ghasemi, Shahin Sanaye Hajari, Mahdi Aghayan, Mahyar Shirshekan, Oveis Hasanpour, Fereydoun Abbasi Davani, Mohammad Lamehi Rachti
Abstract Due to Iran's growing need for accelerators in various applications, NSTRI (Nuclear Science and Technology Research Institute) has defined a 6 MeV e-Linac (electron linear accelerator) project for medical and inspection applications. This electron accelerator has a side-coupled standing wave tube that operates in π/2 mode at the frequency of 2998.5 MHz. This paper presents a summary of the construction and cold test stage of the prototype tube for this accelerator. The prototype tube was constructed from aluminum and clamped with bolts.In the cold test stage, low-power RF measurements werecarried out using a side-coupled cavity tuning method and a bead-pull measurement technique. Using a network analyzer, magnetic and electric probes, and a mechanical structure constructed for this tube made the RF tuning possible. After tuning, the resonant frequency, unloaded quality factor, and effective shunt impedance of the aluminum tube were achieved at 2998.57 MHz, 7970, and 83.25 MΩ/m respectively.
{"title":"Construction and measurement of the prototype side-coupled standing-wave tube for electron Linac","authors":"Sara Zarei, Farshad Ghasemi, Shahin Sanaye Hajari, Mahdi Aghayan, Mahyar Shirshekan, Oveis Hasanpour, Fereydoun Abbasi Davani, Mohammad Lamehi Rachti","doi":"10.1088/1748-0221/18/10/t10006","DOIUrl":"https://doi.org/10.1088/1748-0221/18/10/t10006","url":null,"abstract":"Abstract Due to Iran's growing need for accelerators in various applications, NSTRI (Nuclear Science and Technology Research Institute) has defined a 6 MeV e-Linac (electron linear accelerator) project for medical and inspection applications. This electron accelerator has a side-coupled standing wave tube that operates in π/2 mode at the frequency of 2998.5 MHz. This paper presents a summary of the construction and cold test stage of the prototype tube for this accelerator. The prototype tube was constructed from aluminum and clamped with bolts.In the cold test stage, low-power RF measurements werecarried out using a side-coupled cavity tuning method and a bead-pull measurement technique. Using a network analyzer, magnetic and electric probes, and a mechanical structure constructed for this tube made the RF tuning possible. After tuning, the resonant frequency, unloaded quality factor, and effective shunt impedance of the aluminum tube were achieved at 2998.57 MHz, 7970, and 83.25 MΩ/m respectively.","PeriodicalId":16184,"journal":{"name":"Journal of Instrumentation","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136153289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.1088/1748-0221/18/10/p10001
A. Martens, F. Mawas, F. Zomer
Abstract Several new high-energy physics accelerators will exploit beam polarization as a core part of their program. In several cases the beam polarization needs to be accurately measured with a precision better than one per-mille. At this level of precision, α 3 QED corrections must be accounted for. In this paper, we estimate the related correction for the detectors considered for several projects as ILC and FCC-ee. Two different techniques to extract the beam polarization are investigated and found to provide complementary information. The related measurements are dominated by different sources of systematic uncertainties, either related to QED corrections or likely to uncontrolled variations of experimental conditions at the per-mille level. It is found in particular that the measurement of the spatial distribution of photons, besides experimental challenges, is more sensitive to QED corrections than the technique consisting in measuring electrons spatial and energy distribution.
{"title":"A quantitative study of systematic uncertainties due to QED corrections in accurate Compton polarimetry experiments","authors":"A. Martens, F. Mawas, F. Zomer","doi":"10.1088/1748-0221/18/10/p10001","DOIUrl":"https://doi.org/10.1088/1748-0221/18/10/p10001","url":null,"abstract":"Abstract Several new high-energy physics accelerators will exploit beam polarization as a core part of their program. In several cases the beam polarization needs to be accurately measured with a precision better than one per-mille. At this level of precision, α 3 QED corrections must be accounted for. In this paper, we estimate the related correction for the detectors considered for several projects as ILC and FCC-ee. Two different techniques to extract the beam polarization are investigated and found to provide complementary information. The related measurements are dominated by different sources of systematic uncertainties, either related to QED corrections or likely to uncontrolled variations of experimental conditions at the per-mille level. It is found in particular that the measurement of the spatial distribution of photons, besides experimental challenges, is more sensitive to QED corrections than the technique consisting in measuring electrons spatial and energy distribution.","PeriodicalId":16184,"journal":{"name":"Journal of Instrumentation","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135457743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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