Pub Date : 2025-12-30DOI: 10.1016/j.nima.2025.171259
S. Terui , T. Ishibashi , M. Shirai , X. Jin , M. Yao , K. Shibata , T. Abe , N. Akita , A. Natochii , Q. Liu
Currently, SuperKEKB faces the challenge of sudden beam loss (SBL), which occurs with almost no prior warning, and the causes of SBL are not yet fully understood. A damaged collimator has a reduced ability to suppress beam background noise (BG) compared to an undamaged collimator. When BG suppression decreases, operation must be stopped and the collimator jaw replaced. Therefore, a robust collimator head material is required. In this study, we investigated the material properties of copper-carbide graphite (CuGr) as a candidate collimator head material for SuperKEKB and future electron/positron colliders in terms of its electrical conductivity in the high-frequency region, secondary electron yield, outgassing rate owing to photon-stimulated desorption, and amount of dust generated by the ultrasonic cleaning of CuGr. The results were compared with the simulation results of the beam background with CuGr. According to the study findings, CuGr can be effectively used as the collimator head material. Its use in SuperKEKB and future ring colliders is expected to contribute to stable accelerator operation.
{"title":"Investigation of new collimator head material candidates for SuperKEKB and future electron/positron colliders","authors":"S. Terui , T. Ishibashi , M. Shirai , X. Jin , M. Yao , K. Shibata , T. Abe , N. Akita , A. Natochii , Q. Liu","doi":"10.1016/j.nima.2025.171259","DOIUrl":"10.1016/j.nima.2025.171259","url":null,"abstract":"<div><div>Currently, SuperKEKB faces the challenge of sudden beam loss (SBL), which occurs with almost no prior warning, and the causes of SBL are not yet fully understood. A damaged collimator has a reduced ability to suppress beam background noise (BG) compared to an undamaged collimator. When BG suppression decreases, operation must be stopped and the collimator jaw replaced. Therefore, a robust collimator head material is required. In this study, we investigated the material properties of copper-carbide graphite (CuGr) as a candidate collimator head material for SuperKEKB and future electron/positron colliders in terms of its electrical conductivity in the high-frequency region, secondary electron yield, outgassing rate owing to photon-stimulated desorption, and amount of dust generated by the ultrasonic cleaning of CuGr. The results were compared with the simulation results of the beam background with CuGr. According to the study findings, CuGr can be effectively used as the collimator head material. Its use in SuperKEKB and future ring colliders is expected to contribute to stable accelerator operation.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171259"},"PeriodicalIF":1.4,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-29DOI: 10.1016/j.nima.2025.171266
Eric Laloy, Md Moudud Hasan, Bart Rogiers, Wouter Broeckx, Arne Vandenbrande, An Bielen
This work introduces a novel Bayesian approach for interpreting total gamma clearance monitoring data. The approach integrates spatial and spectral information from the measurements with a surrogate efficiency model, all within a Bayesian inference framework, to estimate the spatial activity distribution across 15 subvolumes inside a 200-liter waste drum. When the / ratio is not known a priori, it can be jointly estimated alongside other variables of interest. Virtual and real mock-up experiments demonstrate that the method accurately identifies high-activity subvolumes and reconstructs the relative spatial activity distribution. Moreover, with reliable background count estimates, the total drum activity can be determined with a relative error below 10%. Tests on two real low-level waste drums, validated against HPGe-based gamma spectrometry, confirm a maximum relative error of 10%. Regarding inference of the / ratio, the approach correctly detects drums containing only but underestimates the fraction when is present. Our proposed approach has also some practical limitations, mainly its reliance on prior knowledge of the drum’s filling level being close to 100% and, to a lesser extent, its underlying assumption of a constant density across the drum. Future work will aim to solve that issue by incorporating filling degree into the surrogate efficiency model.
{"title":"Bayesian inference for total gamma clearance monitors: Accounting for both spatial and spectral information","authors":"Eric Laloy, Md Moudud Hasan, Bart Rogiers, Wouter Broeckx, Arne Vandenbrande, An Bielen","doi":"10.1016/j.nima.2025.171266","DOIUrl":"10.1016/j.nima.2025.171266","url":null,"abstract":"<div><div>This work introduces a novel Bayesian approach for interpreting total gamma clearance monitoring data. The approach integrates spatial and spectral information from the measurements with a surrogate efficiency model, all within a Bayesian inference framework, to estimate the spatial activity distribution across 15 subvolumes inside a 200-liter waste drum. When the <span><math><mrow><msup><mrow></mrow><mrow><mi>60</mi></mrow></msup><mtext>Co</mtext></mrow></math></span>/<span><math><mrow><msup><mrow></mrow><mrow><mi>137</mi></mrow></msup><mtext>Cs</mtext></mrow></math></span> ratio is not known a priori, it can be jointly estimated alongside other variables of interest. Virtual and real mock-up experiments demonstrate that the method accurately identifies high-activity subvolumes and reconstructs the relative spatial activity distribution. Moreover, with reliable background count estimates, the total drum activity can be determined with a relative error below 10%. Tests on two real low-level waste drums, validated against HPGe-based gamma spectrometry, confirm a maximum relative error of 10%. Regarding inference of the <span><math><mrow><msup><mrow></mrow><mrow><mi>60</mi></mrow></msup><mtext>Co</mtext></mrow></math></span>/<span><math><mrow><msup><mrow></mrow><mrow><mi>137</mi></mrow></msup><mtext>Cs</mtext></mrow></math></span> ratio, the approach correctly detects drums containing only <span><math><mrow><msup><mrow></mrow><mrow><mi>137</mi></mrow></msup><mtext>Cs</mtext></mrow></math></span> but underestimates the <span><math><mrow><msup><mrow></mrow><mrow><mi>60</mi></mrow></msup><mtext>Co</mtext></mrow></math></span> fraction when <span><math><mrow><msup><mrow></mrow><mrow><mi>60</mi></mrow></msup><mtext>Co</mtext></mrow></math></span> is present. Our proposed approach has also some practical limitations, mainly its reliance on prior knowledge of the drum’s filling level being close to 100% and, to a lesser extent, its underlying assumption of a constant density across the drum. Future work will aim to solve that issue by incorporating filling degree into the surrogate efficiency model.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171266"},"PeriodicalIF":1.4,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145924696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present a statistical method for detecting and analysing state changes in experimental measurements using the Cuscore statistic and its special case, the Centred Cuscore statistic. These statistics are designed to identify deviations in detector responses using sequential hypothesis testing relative to a defined reference state. Applications to charge-changing reaction experiments at the FRagment Separator facility at the GSI Helmholtz Centre for Heavy Ion Research, Germany, and the Second Radioactive Ion Beam Line in Lanzhou at the Institute of Modern Physics, China, demonstrate the ability of these tools to quantify state changes, identify the change point, and classify data segments based on measured states. For long-term online monitoring, we use the exponentially weighted moving average to continuously update computations, enabling the detection of successive changes. This method supports both real-time and post-experiment diagnostics and provides a robust approach for enhancing data integrity and experimental control in nuclear physics and related fields.
{"title":"Identification and online monitoring of experimental measurement states via Cuscore statistic","authors":"Jichao Zhang , Baohua Sun , Isao Tanihata , Zilun Shen","doi":"10.1016/j.nima.2025.171267","DOIUrl":"10.1016/j.nima.2025.171267","url":null,"abstract":"<div><div>We present a statistical method for detecting and analysing state changes in experimental measurements using the Cuscore statistic and its special case, the Centred Cuscore statistic. These statistics are designed to identify deviations in detector responses using sequential hypothesis testing relative to a defined reference state. Applications to charge-changing reaction experiments at the FRagment Separator facility at the GSI Helmholtz Centre for Heavy Ion Research, Germany, and the Second Radioactive Ion Beam Line in Lanzhou at the Institute of Modern Physics, China, demonstrate the ability of these tools to quantify state changes, identify the change point, and classify data segments based on measured states. For long-term online monitoring, we use the exponentially weighted moving average to continuously update computations, enabling the detection of successive changes. This method supports both real-time and post-experiment diagnostics and provides a robust approach for enhancing data integrity and experimental control in nuclear physics and related fields.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171267"},"PeriodicalIF":1.4,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-27DOI: 10.1016/j.nima.2025.171261
Ippei Yamada, Kunihiro Kojima, Motoki Chimura
A non-invasive beam profile monitor is indispensable for stable operation of a high-intensity particle accelerator. Two types based on beam-gas interaction have been developed at many institutes: the residual gas type and the gas injection type. The gas injection method enables a high-speed or accurate profile measurements due to the high secondary particle yield, in contrast to the residual gas type. However, gas injection may affect the beam quality, and a quantitative evaluation of non-invasiveness is essential. Charge exchange and phase-space distribution change of a negative hydrogen ion (H) beam induced by beam-gas interaction were quantified. The charge exchange was assessed through measurement of the beam current reduction, and the beam loss linearly increased with the injected gas flux, as consistent with the charge-exchange cross-section within a possible error range. Phase-space distributions with and without gas injection were measured, and the emittance reduced by about 5%, rather than increased due to scattering, when the beam line pressure was raised from 10−6 Pa to 10−3 Pa. An analytical approach and a particle-in-cell simulation revealed that the mitigation of the H beam’s space charge by ions generated in the beam-gas interaction induced the emittance reduction: a space-charge neutralization/compensation effect. In addition to the emittance reduction, the beam envelope exhibited a non-negligible lens effect due to the neutralization, and we devised a correction term including no arbitrariness under steady state of the neutralization.
{"title":"Non-invasiveness evaluation of gas-sheet beam profile monitor: Observation of emittance reduction due to space-charge neutralization","authors":"Ippei Yamada, Kunihiro Kojima, Motoki Chimura","doi":"10.1016/j.nima.2025.171261","DOIUrl":"10.1016/j.nima.2025.171261","url":null,"abstract":"<div><div>A non-invasive beam profile monitor is indispensable for stable operation of a high-intensity particle accelerator. Two types based on beam-gas interaction have been developed at many institutes: the residual gas type and the gas injection type. The gas injection method enables a high-speed or accurate profile measurements due to the high secondary particle yield, in contrast to the residual gas type. However, gas injection may affect the beam quality, and a quantitative evaluation of non-invasiveness is essential. Charge exchange and phase-space distribution change of a negative hydrogen ion (H<span><math><msup><mrow></mrow><mrow><mo>−</mo></mrow></msup></math></span>) beam induced by beam-gas interaction were quantified. The charge exchange was assessed through measurement of the beam current reduction, and the beam loss linearly increased with the injected gas flux, as consistent with the charge-exchange cross-section within a possible error range. Phase-space distributions with and without gas injection were measured, and the emittance reduced by about 5%, rather than increased due to scattering, when the beam line pressure was raised from 10<sup>−6</sup> Pa to 10<sup>−3</sup> Pa. An analytical approach and a particle-in-cell simulation revealed that the mitigation of the H<span><math><msup><mrow></mrow><mrow><mo>−</mo></mrow></msup></math></span> beam’s space charge by ions generated in the beam-gas interaction induced the emittance reduction: a space-charge neutralization/compensation effect. In addition to the emittance reduction, the beam envelope exhibited a non-negligible lens effect due to the neutralization, and we devised a correction term including no arbitrariness under steady state of the neutralization.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171261"},"PeriodicalIF":1.4,"publicationDate":"2025-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-27DOI: 10.1016/j.nima.2025.171262
L. Gioacchini , A. Lega , R. Nicolaidis , F. Nozzoli
<div><div>Lutetium–yttrium oxyorthosilicate (LYSO) crystals are widely recognized as fast scintillators, valued for their high light output and robust mechanical properties, which make them well suited for high-energy physics and space applications despite their intrinsic radioactivity. Although the non-proportional light response of LYSO scintillators has been extensively studied, discrepancies remain among published measurements of the light-yield quenching at high ionization densities with different charged particles. We report a measurement of the light response of a LYSO scintillator to stopping <span><math><mi>α</mi></math></span> particles emitted by a <sup>241</sup>Am source performed in the laboratories of the University of Trento. A quenching factor, L/E <span><math><mo>=</mo></math></span> 0.075<span><math><mrow><mspace></mspace><mo>±</mo><mspace></mspace><mn>0</mn><mo>.</mo><mn>006</mn></mrow></math></span>, for <span><math><mrow><mn>3</mn><mo>.</mo><mn>7</mn><mspace></mspace><mspace></mspace><mi>MeV</mi></mrow></math></span> <span><math><mi>α</mi></math></span> particles has been inferred, in agreement with previous results obtained with He ions.</div><div>The time distribution of the scintillation decay has also been investigated, confirming the presence of two exponential components in the decay tail: <span><math><mrow><msub><mrow><mi>τ</mi></mrow><mrow><mtext>fast</mtext></mrow></msub><mo>=</mo><mn>23</mn><mo>.</mo><mn>3</mn><mspace></mspace><mo>±</mo><mspace></mspace><mn>0</mn><mo>.</mo><msup><mrow><mn>7</mn></mrow><mrow><mrow><mo>(</mo><mtext>stat.</mtext><mo>)</mo></mrow></mrow></msup><mo>±</mo><mn>0</mn><mo>.</mo><msup><mrow><mn>8</mn></mrow><mrow><mrow><mo>(</mo><mtext>syst.</mtext><mo>)</mo></mrow></mrow></msup><mspace></mspace><mspace></mspace><mi>ns</mi></mrow></math></span> and <span><math><mrow><msub><mrow><mi>τ</mi></mrow><mrow><mtext>slow</mtext></mrow></msub><mo>=</mo><mn>43</mn><mo>.</mo><mn>9</mn><mspace></mspace><mo>±</mo><mspace></mspace><mn>0</mn><mo>.</mo><msup><mrow><mn>5</mn></mrow><mrow><mrow><mo>(</mo><mtext>stat.</mtext><mo>)</mo></mrow></mrow></msup><mspace></mspace><mo>±</mo><mspace></mspace><mn>2</mn><mo>.</mo><msup><mrow><mn>3</mn></mrow><mrow><mrow><mo>(</mo><mtext>syst.</mtext><mo>)</mo></mrow></mrow></msup><mspace></mspace><mspace></mspace><mi>ns</mi></mrow></math></span>. The current measurement revealed that <span><math><mi>α</mi></math></span> scintillation pulses are faster than <span><math><mrow><mi>β</mi><mo>/</mo><mi>γ</mi></mrow></math></span> ones. This behavior is quantitatively parameterized by a difference in the amplitude of the two scintillation components: <span><math><mrow><msubsup><mrow><mi>A</mi></mrow><mrow><mtext>slow</mtext></mrow><mrow><mi>α</mi></mrow></msubsup><mo>=</mo><mrow><mo>(</mo><mn>48</mn><mo>.</mo><mn>7</mn><mspace></mspace><mo>±</mo><mspace></mspace><mn>3</mn><mo>.</mo><msup><mrow><mn>3</mn></mrow><mrow><mrow><mo>(</mo><mtext>stat.</mtext><mo>)</mo></mrow></mrow></ms
{"title":"Characterization of the light response of LYSO scintillator to α particles","authors":"L. Gioacchini , A. Lega , R. Nicolaidis , F. Nozzoli","doi":"10.1016/j.nima.2025.171262","DOIUrl":"10.1016/j.nima.2025.171262","url":null,"abstract":"<div><div>Lutetium–yttrium oxyorthosilicate (LYSO) crystals are widely recognized as fast scintillators, valued for their high light output and robust mechanical properties, which make them well suited for high-energy physics and space applications despite their intrinsic radioactivity. Although the non-proportional light response of LYSO scintillators has been extensively studied, discrepancies remain among published measurements of the light-yield quenching at high ionization densities with different charged particles. We report a measurement of the light response of a LYSO scintillator to stopping <span><math><mi>α</mi></math></span> particles emitted by a <sup>241</sup>Am source performed in the laboratories of the University of Trento. A quenching factor, L/E <span><math><mo>=</mo></math></span> 0.075<span><math><mrow><mspace></mspace><mo>±</mo><mspace></mspace><mn>0</mn><mo>.</mo><mn>006</mn></mrow></math></span>, for <span><math><mrow><mn>3</mn><mo>.</mo><mn>7</mn><mspace></mspace><mspace></mspace><mi>MeV</mi></mrow></math></span> <span><math><mi>α</mi></math></span> particles has been inferred, in agreement with previous results obtained with He ions.</div><div>The time distribution of the scintillation decay has also been investigated, confirming the presence of two exponential components in the decay tail: <span><math><mrow><msub><mrow><mi>τ</mi></mrow><mrow><mtext>fast</mtext></mrow></msub><mo>=</mo><mn>23</mn><mo>.</mo><mn>3</mn><mspace></mspace><mo>±</mo><mspace></mspace><mn>0</mn><mo>.</mo><msup><mrow><mn>7</mn></mrow><mrow><mrow><mo>(</mo><mtext>stat.</mtext><mo>)</mo></mrow></mrow></msup><mo>±</mo><mn>0</mn><mo>.</mo><msup><mrow><mn>8</mn></mrow><mrow><mrow><mo>(</mo><mtext>syst.</mtext><mo>)</mo></mrow></mrow></msup><mspace></mspace><mspace></mspace><mi>ns</mi></mrow></math></span> and <span><math><mrow><msub><mrow><mi>τ</mi></mrow><mrow><mtext>slow</mtext></mrow></msub><mo>=</mo><mn>43</mn><mo>.</mo><mn>9</mn><mspace></mspace><mo>±</mo><mspace></mspace><mn>0</mn><mo>.</mo><msup><mrow><mn>5</mn></mrow><mrow><mrow><mo>(</mo><mtext>stat.</mtext><mo>)</mo></mrow></mrow></msup><mspace></mspace><mo>±</mo><mspace></mspace><mn>2</mn><mo>.</mo><msup><mrow><mn>3</mn></mrow><mrow><mrow><mo>(</mo><mtext>syst.</mtext><mo>)</mo></mrow></mrow></msup><mspace></mspace><mspace></mspace><mi>ns</mi></mrow></math></span>. The current measurement revealed that <span><math><mi>α</mi></math></span> scintillation pulses are faster than <span><math><mrow><mi>β</mi><mo>/</mo><mi>γ</mi></mrow></math></span> ones. This behavior is quantitatively parameterized by a difference in the amplitude of the two scintillation components: <span><math><mrow><msubsup><mrow><mi>A</mi></mrow><mrow><mtext>slow</mtext></mrow><mrow><mi>α</mi></mrow></msubsup><mo>=</mo><mrow><mo>(</mo><mn>48</mn><mo>.</mo><mn>7</mn><mspace></mspace><mo>±</mo><mspace></mspace><mn>3</mn><mo>.</mo><msup><mrow><mn>3</mn></mrow><mrow><mrow><mo>(</mo><mtext>stat.</mtext><mo>)</mo></mrow></mrow></ms","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171262"},"PeriodicalIF":1.4,"publicationDate":"2025-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-27DOI: 10.1016/j.nima.2025.171260
X.T. Yu , F.Y. Liu , H.Q. Zhang , P. Zhang , P. Kuang , X.Z. Cao , B.Y. Wang
A high intensity, high time resolution pulsed slow positron beam was developed, integrating a 40 mCi 22Na source, solid-Ne moderator, and a three-stage pulsing unit (chopper, prebuncher, buncher), achieving 3.6 × 105 e+/s intensity and 187 ps resolution. Using particle dynamics simulations, we investigated how the large energy spread of the beam moderated by solid Ne affects pulse bunching and optimized the system from both the chopping and bunching perspectives. To meet the system's stringent requirements for pulsed signals, a compact RF electronics was developed with integrated amplification, biasing, isolation, impedance matching, and high-voltage protection. To demonstrate the system performance, positron lifetime measurements were carried out on several materials, including multilayer nanofilms. The results demonstrate that the developed platform offers a powerful and versatile tool for analyzing microstructural defects, free-volume distributions, and interfacial phenomena in advanced materials.
{"title":"Development of pulsed slow positron beam with high intensity and high time resolution","authors":"X.T. Yu , F.Y. Liu , H.Q. Zhang , P. Zhang , P. Kuang , X.Z. Cao , B.Y. Wang","doi":"10.1016/j.nima.2025.171260","DOIUrl":"10.1016/j.nima.2025.171260","url":null,"abstract":"<div><div>A high intensity, high time resolution pulsed slow positron beam was developed, integrating a 40 mCi <sup>22</sup>Na source, solid-Ne moderator, and a three-stage pulsing unit (chopper, prebuncher, buncher), achieving 3.6 × 10<sup>5</sup> e<sup>+</sup>/s intensity and 187 ps resolution. Using particle dynamics simulations, we investigated how the large energy spread of the beam moderated by solid Ne affects pulse bunching and optimized the system from both the chopping and bunching perspectives. To meet the system's stringent requirements for pulsed signals, a compact RF electronics was developed with integrated amplification, biasing, isolation, impedance matching, and high-voltage protection. To demonstrate the system performance, positron lifetime measurements were carried out on several materials, including multilayer nanofilms. The results demonstrate that the developed platform offers a powerful and versatile tool for analyzing microstructural defects, free-volume distributions, and interfacial phenomena in advanced materials.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171260"},"PeriodicalIF":1.4,"publicationDate":"2025-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-26DOI: 10.1016/j.nima.2025.171258
B.M. Harvey , L. Knull , T. Hankins , M.D. Youngs , K. Hagel , A.B. McIntosh , S.J. Yennello
Modern nuclear physics experiments often use telescopic detector systems to identify reaction products on a particle-by-particle basis. These telescopes exploit the dependence of differential energy loss on nuclide charge and mass; by correlating the amount of energy deposited in the thin () and thick () layers of a telescope, different nuclides populate different regions of this - in the form of distinct curved bands. Particle identification is then accomplished by drawing 2-D gates around these bands. However, this approach is laborious and often imprecise, susceptible to subjective or inconsistent gate placement. One improvement to this is to instead draw guidelines along the data and use these to project the 2-D - into a 1-D space; here, inconsistencies are significantly easier to identify and iteratively correct. While this helps reduce systematic error, the approach remains laborious, especially for complex multi-detector arrays. To address these challenges, the Texas Automated Particle Identification Routine (TAPIR), a new semi-automated linearization procedure, has been developed. Using modern image processing techniques, TAPIR enables consistent and efficient linearizations, reducing the time required to linearize detectors while simultaneously producing a more accurate linearization than is practically achievable through manual methods. An example linearization is provided for a Forward Array Using Silicon Technology (FAUST) detector telescope to outline the method and then compare against a manual linearization, together illustrating the precision, accuracy, and relative simplicity of this technique.
{"title":"A fast, semi-automated dimension reduction procedure for particle identification data in telescope detectors","authors":"B.M. Harvey , L. Knull , T. Hankins , M.D. Youngs , K. Hagel , A.B. McIntosh , S.J. Yennello","doi":"10.1016/j.nima.2025.171258","DOIUrl":"10.1016/j.nima.2025.171258","url":null,"abstract":"<div><div>Modern nuclear physics experiments often use telescopic detector systems to identify reaction products on a particle-by-particle basis. These telescopes exploit the dependence of differential energy loss on nuclide charge and mass; by correlating the amount of energy deposited in the thin (<span><math><mrow><mi>Δ</mi><mi>E</mi></mrow></math></span>) and thick (<span><math><mi>E</mi></math></span>) layers of a telescope, different nuclides populate different regions of this <span><math><mrow><mi>Δ</mi><mi>E</mi></mrow></math></span>-<span><math><mi>E</mi></math></span> in the form of distinct curved bands. Particle identification is then accomplished by drawing 2-D gates around these bands. However, this approach is laborious and often imprecise, susceptible to subjective or inconsistent gate placement. One improvement to this is to instead draw guidelines along the data and use these to project the 2-D <span><math><mrow><mi>Δ</mi><mi>E</mi></mrow></math></span>-<span><math><mi>E</mi></math></span> into a 1-D space; here, inconsistencies are significantly easier to identify and iteratively correct. While this helps reduce systematic error, the approach remains laborious, especially for complex multi-detector arrays. To address these challenges, the Texas Automated Particle Identification Routine (TAPIR), a new semi-automated linearization procedure, has been developed. Using modern image processing techniques, TAPIR enables consistent and efficient linearizations, reducing the time required to linearize detectors while simultaneously producing a more accurate linearization than is practically achievable through manual methods. An example linearization is provided for a Forward Array Using Silicon Technology (FAUST) detector telescope to outline the method and then compare against a manual linearization, together illustrating the precision, accuracy, and relative simplicity of this technique.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171258"},"PeriodicalIF":1.4,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-25DOI: 10.1016/j.nima.2025.171232
N.J. Sas , A.J. Krasznahorkay , M. Csatlos , L. Csige , J. Molnar , Z. Pintye , S. Czellár
A new ee pair spectrometer was developed having six particle telescopes in a close geometry with a total solid angle of about 20% of 4. Each telescope consists of two layers of thin, position-sensitive silicon detectors and a large plastic scintillator to identify and track the electrons and positrons, as well as to measure their kinetic energies. The spectrometer was calibrated with selected nuclear reactions [19F(p, )16O, 7Li(p, )8Be, 11B(p, )12C] producing ee pairs by internal pair creation, and the results were compared to Monte Carlo simulations performed with geant4. Compared to the previous spectrometers constructed at ATOMKI to study the X17 anomaly, the background induced by cosmic rays was reduced by about a factor of 12, while the -ray–related background decreased by roughly a factor of two due to the implementation of particle tracking.
{"title":"High efficiency electron–positron pair spectrometer for the study of light bosons","authors":"N.J. Sas , A.J. Krasznahorkay , M. Csatlos , L. Csige , J. Molnar , Z. Pintye , S. Czellár","doi":"10.1016/j.nima.2025.171232","DOIUrl":"10.1016/j.nima.2025.171232","url":null,"abstract":"<div><div>A new e<span><math><msup><mrow></mrow><mrow><mo>+</mo></mrow></msup></math></span>e<span><math><msup><mrow></mrow><mrow><mo>−</mo></mrow></msup></math></span> pair spectrometer was developed having six particle telescopes in a close geometry with a total solid angle of about 20% of 4<span><math><mi>π</mi></math></span>. Each telescope consists of two layers of thin, position-sensitive silicon detectors and a large plastic scintillator to identify and track the electrons and positrons, as well as to measure their kinetic energies. The spectrometer was calibrated with selected nuclear reactions [<sup>19</sup>F(p, <span><math><mi>α</mi></math></span>)<sup>16</sup>O, <sup>7</sup>Li(p, <span><math><mi>γ</mi></math></span>)<sup>8</sup>Be, <sup>11</sup>B(p, <span><math><mi>γ</mi></math></span>)<sup>12</sup>C] producing e<span><math><msup><mrow></mrow><mrow><mo>+</mo></mrow></msup></math></span>e<span><math><msup><mrow></mrow><mrow><mo>−</mo></mrow></msup></math></span> pairs by internal pair creation, and the results were compared to Monte Carlo simulations performed with <span>geant4</span>. Compared to the previous spectrometers constructed at ATOMKI to study the X17 anomaly, the background induced by cosmic rays was reduced by about a factor of 12, while the <span><math><mi>γ</mi></math></span>-ray–related background decreased by roughly a factor of two due to the implementation of particle tracking.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171232"},"PeriodicalIF":1.4,"publicationDate":"2025-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-24DOI: 10.1016/j.nima.2025.171248
Y.-X. Liu , T. Koga , H. Bae , Y. Yang , C. Kiesling , F. Meggendorfer , K. Unger , S. Hiesl , T. Forsthofer , A. Ishikawa , Y. Ahn , T. Ferber , I. Haide , G. Heine , C.-L. Hsu , A. Little , H. Nakazawa , M. Neu , L. Reuter , V. Savinov , Z. Xu
The Belle II experiment at the SuperKEKB accelerator is designed to explore physics beyond the Standard Model with unprecedented luminosity. As the beam intensity increased, the experiment faced significant challenges due to higher beam-induced background, leading to a high trigger rate and placing limitations on further luminosity increases. To address this problem, we developed trigger logic for tracking using deep neural network (DNN) technology on an FPGA for the Belle II hardware trigger system, employing high-level synthesis techniques. By leveraging drift time and hit pattern information from the Central Drift Chamber and incorporating a simplified self-attention architecture, the DNN track trigger significantly improves track reconstruction performance at the hardware level. Compared to the existing neural track trigger, our implementation reduces the total track trigger rate by 37% while improving average efficiency for the signal tracks from 96% to 98% for charged tracks with transverse momentum GeV. This upgrade ensures the long-term viability of the Belle II data acquisition system as luminosity continues to increase.
{"title":"Development of deep neural network first-level hardware track trigger for the Belle II experiment","authors":"Y.-X. Liu , T. Koga , H. Bae , Y. Yang , C. Kiesling , F. Meggendorfer , K. Unger , S. Hiesl , T. Forsthofer , A. Ishikawa , Y. Ahn , T. Ferber , I. Haide , G. Heine , C.-L. Hsu , A. Little , H. Nakazawa , M. Neu , L. Reuter , V. Savinov , Z. Xu","doi":"10.1016/j.nima.2025.171248","DOIUrl":"10.1016/j.nima.2025.171248","url":null,"abstract":"<div><div>The Belle II experiment at the SuperKEKB accelerator is designed to explore physics beyond the Standard Model with unprecedented luminosity. As the beam intensity increased, the experiment faced significant challenges due to higher beam-induced background, leading to a high trigger rate and placing limitations on further luminosity increases. To address this problem, we developed trigger logic for tracking using deep neural network (DNN) technology on an FPGA for the Belle II hardware trigger system, employing high-level synthesis techniques. By leveraging drift time and hit pattern information from the Central Drift Chamber and incorporating a simplified self-attention architecture, the DNN track trigger significantly improves track reconstruction performance at the hardware level. Compared to the existing neural track trigger, our implementation reduces the total track trigger rate by 37% while improving average efficiency for the signal tracks from 96% to 98% for charged tracks with transverse momentum <span><math><mrow><mo>></mo><mn>0</mn><mo>.</mo><mn>3</mn></mrow></math></span> <!--> <!-->GeV. This upgrade ensures the long-term viability of the Belle II data acquisition system as luminosity continues to increase.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171248"},"PeriodicalIF":1.4,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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