Pub Date : 2025-02-07DOI: 10.1016/j.nima.2025.170306
Renmu Zhang , Jun Wang , Lihua Wang , Biao Deng , Jun Hu
Synchrotron radiation micro-CT imaging is widely used in various scientific fields as a 3D non-destructive imaging technique with high penetration, high resolution and high contrast. Roots According to the Shannon-Nyquist theorem, sufficient projection data need to be collected to obtain high-quality CT reconstructed slices. In order to improve the temporal resolution of CT, sparse data sampling methods have been proposed. However, images reconstructed from sparse view projections often have severe streak artifacts. In this paper, we propose an artifact correction method swin transformer and convolutional U-net (STC-Unet) for synchrotron sparse CT. The network is based on the structure of U-Net, which combines the local feature extraction capability of convolutional neural network and the global feature extraction capability of Transformer in the encoder part, and reduces the artifacts introduced by the single up-sampling by using a dual up-sampling module in the decoder part. The method is applied to sparse CT experiments on synchrotron radiation metal mesh samples, and the results show that the method has good results in removing artifacts while preserving structural details. Compared with other methods, the quantitative evaluation of our proposed model is significantly improved.
{"title":"Synchrotron based sparse-view CT artifact correction with STC-UNet","authors":"Renmu Zhang , Jun Wang , Lihua Wang , Biao Deng , Jun Hu","doi":"10.1016/j.nima.2025.170306","DOIUrl":"10.1016/j.nima.2025.170306","url":null,"abstract":"<div><div>Synchrotron radiation micro-CT imaging is widely used in various scientific fields as a 3D non-destructive imaging technique with high penetration, high resolution and high contrast. Roots According to the Shannon-Nyquist theorem, sufficient projection data need to be collected to obtain high-quality CT reconstructed slices. In order to improve the temporal resolution of CT, sparse data sampling methods have been proposed. However, images reconstructed from sparse view projections often have severe streak artifacts. In this paper, we propose an artifact correction method swin transformer and convolutional U-net (STC-Unet) for synchrotron sparse CT. The network is based on the structure of U-Net, which combines the local feature extraction capability of convolutional neural network and the global feature extraction capability of Transformer in the encoder part, and reduces the artifacts introduced by the single up-sampling by using a dual up-sampling module in the decoder part. The method is applied to sparse CT experiments on synchrotron radiation metal mesh samples, and the results show that the method has good results in removing artifacts while preserving structural details. Compared with other methods, the quantitative evaluation of our proposed model is significantly improved.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1073 ","pages":"Article 170306"},"PeriodicalIF":1.5,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387689","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 : 2025-02-07DOI: 10.1016/j.nima.2025.170281
Y. Hu , E. Li , C. Ma , C. Mai
A Gas Electron Multiplier (GEM) camera has been used for soft X-ray measurements on the Experimental Advanced Superconducting Tokamak (EAST), and the obtained data after a tomography calculation showed much useful information on the plasma macroscopic instabilities. A large experimental database has been built from the chord-integrated X-ray radiation signal measured by GEM, and we then develop a data-driven tomography method for fast viewing of X-ray emissivity profiles on the plasma cross-section. This tomography method is further applied in analyzing a plasma major disruption event, indicating there exists a vertical displacement event before a plasma current quench. This study suggests that the GEM camera with this fast data-driven tomography would be helpful for further feedback control of fusion plasmas to avoid plasma disruptions.
{"title":"Application of a data-driven tomography method for the Gas Electron Multiplier (GEM) based X-ray camera on EAST","authors":"Y. Hu , E. Li , C. Ma , C. Mai","doi":"10.1016/j.nima.2025.170281","DOIUrl":"10.1016/j.nima.2025.170281","url":null,"abstract":"<div><div>A Gas Electron Multiplier (GEM) camera has been used for soft X-ray measurements on the Experimental Advanced Superconducting Tokamak (EAST), and the obtained data after a tomography calculation showed much useful information on the plasma macroscopic instabilities. A large experimental database has been built from the chord-integrated X-ray radiation signal measured by GEM, and we then develop a data-driven tomography method for fast viewing of X-ray emissivity profiles on the plasma cross-section. This tomography method is further applied in analyzing a plasma major disruption event, indicating there exists a vertical displacement event before a plasma current quench. This study suggests that the GEM camera with this fast data-driven tomography would be helpful for further feedback control of fusion plasmas to avoid plasma disruptions.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1073 ","pages":"Article 170281"},"PeriodicalIF":1.5,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421640","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 : 2025-02-07DOI: 10.1016/j.nima.2025.170305
N. Grundmanis , A. Sarakovskis , A. Lupilov , V. Gostilo , A. Owens , K. Pudzs
In this paper we present the results of measurements on CsPbBr3 perovskite crystals grown by the Bridgman-Stockbarger method which have shown promise as X- and gamma-ray detection media. The crystal structure, trap concentration (3.45 × 1010 cm−3), specific resistivity (1.5 × 109 Ω cm) and other electrophysical characteristics which determine the spectrometric performance were examined. The X- and gamma-ray performance of planar, hemispherical and ring test detectors based on CsPbBr3 crystals of dimensions of 5.0 × 5.0 × 3.0 mm3 were evaluated. The energy resolution of the detector with ring electrodes measured using standard 241Am, 57Co and 137Cs and 60Co radioactive sources was: 2.3 keV (16%) at 14.0 keV; 2.7 keV (4.5%) at 59.5 keV; 12.0 keV (1.8%) at 662 keV and 18.6 keV (1.4%) at 1332 keV. The measured hole mobility-lifetime products (μτ) were as high as 3 × 10−3 cm2/V.
{"title":"The X- and gamma-ray detection properties of CsPbBr3 perovskite crystals grown by the Bridgman–Stockbarger method","authors":"N. Grundmanis , A. Sarakovskis , A. Lupilov , V. Gostilo , A. Owens , K. Pudzs","doi":"10.1016/j.nima.2025.170305","DOIUrl":"10.1016/j.nima.2025.170305","url":null,"abstract":"<div><div>In this paper we present the results of measurements on CsPbBr<sub>3</sub> perovskite crystals grown by the Bridgman-Stockbarger method which have shown promise as X- and gamma-ray detection media. The crystal structure, trap concentration (3.45 × 10<sup>10</sup> cm<sup>−3</sup>), specific resistivity (1.5 × 10<sup>9</sup> Ω cm) and other electrophysical characteristics which determine the spectrometric performance were examined. The X- and gamma-ray performance of planar, hemispherical and ring test detectors based on CsPbBr<sub>3</sub> crystals of dimensions of 5.0 × 5.0 × 3.0 mm<sup>3</sup> were evaluated. The energy resolution of the detector with ring electrodes measured using standard <sup>241</sup>Am, <sup>57</sup>Co and <sup>137</sup>Cs and <sup>60</sup>Co radioactive sources was: 2.3 keV (16%) at 14.0 keV; 2.7 keV (4.5%) at 59.5 keV; 12.0 keV (1.8%) at 662 keV and 18.6 keV (1.4%) at 1332 keV. The measured hole mobility-lifetime products (μτ) were as high as 3 × 10<sup>−3</sup> cm<sup>2</sup>/V.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1073 ","pages":"Article 170305"},"PeriodicalIF":1.5,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421642","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 : 2025-02-06DOI: 10.1016/j.nima.2025.170279
S. Bähr , H. Bae , J. Becker , M. Bertemes , M. Campajola , T. Ferber , T. Forsthofer , S. Hiesl , G. Inguglia , Y. Iwasaki , T. Jülg , C. Kiesling , A.C. Knoll , T. Koga , Y.-T. Lai , A. Lenz , Y. Liu , F. Meggendorfer , H. Nakazawa , M. Neu , J. Yin
We describe the principles and performance of the first-level (“L1”) hardware track trigger of Belle II , which uses the information of Belle II ’s Central Drift Chamber (“CDC”) and provides three-dimensional track candidates based on neural networks. The inputs to the networks are “2D” track candidates in the plane transverse to the electron–positron beams, obtained via Hough transforms, and selected information from the stereo layers of the CDC. The networks then provide estimates for the origin of the track candidates in direction of the colliding beams (“-vertex”), as well as their polar emission angles . Using a suitable cut on the -vertices of the “neural” tracks allows us to identify events coming from the collision region (), and to suppress the overwhelming background from outside. Requiring for at least one neural track in an event with two or more 2D candidates will set an L1 track trigger. The networks also enable a minimum bias trigger, requiring a single 2D track candidate validated by a neural track with a momentum larger than 0.7 GeV in addition to the condition. We also sketch our concepts for upgrading the neural trigger in view of rising instantaneous luminosities, accompanied by increasing backgrounds.
{"title":"The neural network first-level hardware track trigger of the Belle II experiment","authors":"S. Bähr , H. Bae , J. Becker , M. Bertemes , M. Campajola , T. Ferber , T. Forsthofer , S. Hiesl , G. Inguglia , Y. Iwasaki , T. Jülg , C. Kiesling , A.C. Knoll , T. Koga , Y.-T. Lai , A. Lenz , Y. Liu , F. Meggendorfer , H. Nakazawa , M. Neu , J. Yin","doi":"10.1016/j.nima.2025.170279","DOIUrl":"10.1016/j.nima.2025.170279","url":null,"abstract":"<div><div>We describe the principles and performance of the first-level (“L1”) hardware track trigger of Belle II<!--> <!-->, which uses the information of Belle II<!--> <!-->’s Central Drift Chamber (“CDC”) and provides three-dimensional track candidates based on neural networks. The inputs to the networks are “2D” track candidates in the plane transverse to the electron–positron beams, obtained via Hough transforms, and selected information from the stereo layers of the CDC. The networks then provide estimates for the origin of the track candidates in direction of the colliding beams (“<span><math><mi>z</mi></math></span>-vertex”), as well as their polar emission angles <span><math><mi>θ</mi></math></span>. Using a suitable cut <span><math><mi>d</mi></math></span> on the <span><math><mi>z</mi></math></span>-vertices of the “neural” tracks allows us to identify events coming from the collision region (<span><math><mrow><mi>z</mi><mo>≈</mo><mn>0</mn></mrow></math></span>), and to suppress the overwhelming background from outside. Requiring <span><math><mrow><mrow><mo>|</mo><mi>z</mi><mo>|</mo></mrow><mo><</mo><mi>d</mi></mrow></math></span> for at least one neural track in an event with two or more 2D candidates will set an L1 track trigger. The networks also enable a minimum bias trigger, requiring a single 2D track candidate validated by a neural track with a momentum larger than 0.7 GeV in addition to the <span><math><mrow><mo>|</mo><mi>z</mi><mo>|</mo></mrow></math></span> condition. We also sketch our concepts for upgrading the neural trigger in view of rising instantaneous luminosities, accompanied by increasing backgrounds.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1073 ","pages":"Article 170279"},"PeriodicalIF":1.5,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143378864","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 : 2025-02-06DOI: 10.1016/j.nima.2025.170284
Vicky Ullas Mirashi , Winfried Kockelmann , Nikil Kapur , Anna Fedrigo , Manuel Morgano , Thawatchart Chulapakorn , Adrian Losko , Alexander Wolfertz , Anton S. Tremsin , Adriana Matamoros-Veloza
Neutron imaging offers benefits over X-rays for steel corrosion studies including deep penetration and high sensitivity to some light elements such as hydrogen. However, the resolution is frequently at or below the thickness of the corroded layer. This work demonstrates two approaches to enhance the spatial resolution on IMAT at the ISIS neutron source. The first approach shows that a fiber optics taper attached to an optical camera box for white beam imaging can achieve a spatial resolution down to 15 μm. The second approach uses event centroiding with a Timepix3-based detector for diffraction contrast imaging achieving a spatial resolution of 30 μm. These results support advances in corrosion and degradation studies of steel using neutron imaging.
{"title":"Exploring spatial resolution enhancements on IMAT for steel corrosion studies","authors":"Vicky Ullas Mirashi , Winfried Kockelmann , Nikil Kapur , Anna Fedrigo , Manuel Morgano , Thawatchart Chulapakorn , Adrian Losko , Alexander Wolfertz , Anton S. Tremsin , Adriana Matamoros-Veloza","doi":"10.1016/j.nima.2025.170284","DOIUrl":"10.1016/j.nima.2025.170284","url":null,"abstract":"<div><div>Neutron imaging offers benefits over X-rays for steel corrosion studies including deep penetration and high sensitivity to some light elements such as hydrogen. However, the resolution is frequently at or below the thickness of the corroded layer. This work demonstrates two approaches to enhance the spatial resolution on IMAT at the ISIS neutron source. The first approach shows that a fiber optics taper attached to an optical camera box for white beam imaging can achieve a spatial resolution down to 15 μm. The second approach uses event centroiding with a Timepix3-based detector for diffraction contrast imaging achieving a spatial resolution of 30 μm. These results support advances in corrosion and degradation studies of steel using neutron imaging.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1073 ","pages":"Article 170284"},"PeriodicalIF":1.5,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-05DOI: 10.1016/j.nima.2025.170276
Vincenzo Monaco, Elisabetta Durisi, Valeria Monti, Lorenzo Visca
This article presents a model-independent post-processing method to restore the counting and spectral information of pulse-height analyzers in the presence of pulse pileup at high counting rates. The method is based on the measurement of counts and of the integral durations of the detector signals over different thresholds, and on the comparison of the measurements from two sources with the same energy distribution and different counting rates . The procedure does not require the modeling of the pulse shape, the knowledge of the dead-time or other parameters. The correction technique was validated with simulations and with spectra of high activity gamma sources collected with a high-purity germanium (HPGe) detector. For a simulated flat energy distribution and a ratio 2 between the two counting rates, the relative mean deviation between the corrected and input spectra is less than 1% and the relative standard deviation below 5% up to a normalized input rate . These results improve by increasing the difference between the input rates of the two sources. In the simulation of an X-ray spectrum at a normalized input rate , the ratio between the number of corrected and generated counts in each energy bin is below a few percent. The experimental validation was performed by acquiring two spectra of Am sources of different activities placed in a fixed position and of a high activity Cs source placed in two different position. In both cases, the correction method provides count rate distributions in close agreement with a reference spectrum from a lower activity source. The mitigation of artefacts in HPGe spectra overcomes the performance of a standard pileup rejection method.
{"title":"A model-independent method for mitigation of pileup artefacts in energy-resolved radiation counting","authors":"Vincenzo Monaco, Elisabetta Durisi, Valeria Monti, Lorenzo Visca","doi":"10.1016/j.nima.2025.170276","DOIUrl":"10.1016/j.nima.2025.170276","url":null,"abstract":"<div><div>This article presents a model-independent post-processing method to restore the counting and spectral information of pulse-height analyzers in the presence of pulse pileup at high counting rates. The method is based on the measurement of counts and of the integral durations of the detector signals over different thresholds, and on the comparison of the measurements from two sources with the same energy distribution and different counting rates <span><math><mi>ρ</mi></math></span>. The procedure does not require the modeling of the pulse shape, the knowledge of the dead-time <span><math><mi>τ</mi></math></span> or other parameters. The correction technique was validated with simulations and with spectra of high activity gamma sources collected with a high-purity germanium (HPGe) detector. For a simulated flat energy distribution and a ratio 2 between the two counting rates, the relative mean deviation between the corrected and input spectra is less than 1% and the relative standard deviation below 5% up to a normalized input rate <span><math><mrow><mi>ρ</mi><mi>τ</mi><mo>=</mo><mn>1</mn><mo>.</mo><mn>0</mn></mrow></math></span>. These results improve by increasing the difference between the input rates of the two sources. In the simulation of an X-ray spectrum at a normalized input rate <span><math><mrow><mi>ρ</mi><mi>τ</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>5</mn></mrow></math></span>, the ratio between the number of corrected and generated counts in each energy bin is below a few percent. The experimental validation was performed by acquiring two spectra of <span><math><msup><mrow></mrow><mrow><mn>241</mn></mrow></msup></math></span>Am sources of different activities placed in a fixed position and of a high activity <span><math><msup><mrow></mrow><mrow><mn>137</mn></mrow></msup></math></span>Cs source placed in two different position. In both cases, the correction method provides count rate distributions in close agreement with a reference spectrum from a lower activity source. The mitigation of artefacts in HPGe spectra overcomes the performance of a standard pileup rejection method.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1073 ","pages":"Article 170276"},"PeriodicalIF":1.5,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143394662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-05DOI: 10.1016/j.nima.2025.170254
Lushan Wang , Qiang Yang , Qiang Li , Sixin Wu , Bo Peng , Jiaxing Wen , Yue Yang , Wenbo Mo , Yugang Zhou , Ling Miao , Jiazhou Li
In the high-energy astrophysical research, high-power laser-plasma experiments, and many fields, the detection of particles with wide energy range or radiation fields with wide flux range is required. However, the dynamic range of most radiation detector systems are not exceeding four orders of magnitude due to the limiting dynamic range of readout electronic circuits, which cannot satisfy the requirement. This paper proposes a preamplifier circuit design for radiation detectors with high dynamic range and high bandwidth. The preamplifier is a transimpedance amplifier with two feedback loops, featuring a fast trigger and switch circuit to automatically adjust the amplifier’s gain. Ultimately, the circuit achieved a dynamic range of over five orders of magnitude at a 40 MHz bandwidth, reaching 102.59 dB. Used in a liquid scintillation detector readout system, the preamplifier was tested in an n- discrimination experiment. The experimental results show that, coupling the detector with this circuit achieves a larger dynamic range detection and better n- discrimination capability.
{"title":"Design and implementation of a front-end amplifier with over 100 dB dynamic range and 40 MHz bandwidth","authors":"Lushan Wang , Qiang Yang , Qiang Li , Sixin Wu , Bo Peng , Jiaxing Wen , Yue Yang , Wenbo Mo , Yugang Zhou , Ling Miao , Jiazhou Li","doi":"10.1016/j.nima.2025.170254","DOIUrl":"10.1016/j.nima.2025.170254","url":null,"abstract":"<div><div>In the high-energy astrophysical research, high-power laser-plasma experiments, and many fields, the detection of particles with wide energy range or radiation fields with wide flux range is required. However, the dynamic range of most radiation detector systems are not exceeding four orders of magnitude due to the limiting dynamic range of readout electronic circuits, which cannot satisfy the requirement. This paper proposes a preamplifier circuit design for radiation detectors with high dynamic range and high bandwidth. The preamplifier is a transimpedance amplifier with two feedback loops, featuring a fast trigger and switch circuit to automatically adjust the amplifier’s gain. Ultimately, the circuit achieved a dynamic range of over five orders of magnitude at a 40 MHz bandwidth, reaching 102.59 dB. Used in a liquid scintillation detector readout system, the preamplifier was tested in an n-<span><math><mi>γ</mi></math></span> discrimination experiment. The experimental results show that, coupling the detector with this circuit achieves a larger dynamic range detection and better n-<span><math><mi>γ</mi></math></span> discrimination capability.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1073 ","pages":"Article 170254"},"PeriodicalIF":1.5,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143128791","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 : 2025-02-05DOI: 10.1016/j.nima.2025.170278
Stefan Gmuca, Ján Kliman
Thin and thick oxygen-rich targets of metal-oxide WO powder were prepared using an in-air version of the high-energy vibrational powder plating method. The targets are intended to be used for elastic backscattering applications of 16O(, ) and 16O(p,p) resonances at 3038 keV and 3473 keV, respectively, in the beam energy calibration of small accelerators. The high resolution optical microscopy method and X-ray fluorescence technique were used to characterize the targets deposited on various backing substrates. It was shown that the distribution of tungsten in the deposited layers is homogeneous and uniform. From the stoichiometric preservation of the method, the homogeneity and uniformity of the O distribution are deduced. The results indicate that the method used is a viable and effective technique for preparing high-quality nuclear targets, with significant implications for elastic backscattering experiments and other applications in nuclear physics.
{"title":"Fabrication of oxygen-rich targets for elastic backscattering applications using the high-energy vibrational powder plating method","authors":"Stefan Gmuca, Ján Kliman","doi":"10.1016/j.nima.2025.170278","DOIUrl":"10.1016/j.nima.2025.170278","url":null,"abstract":"<div><div>Thin and thick oxygen-rich targets of metal-oxide WO<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> powder were prepared using an in-air version of the high-energy vibrational powder plating method. The targets are intended to be used for elastic backscattering applications of <sup>16</sup>O(<span><math><mi>α</mi></math></span>, <span><math><mi>α</mi></math></span>) and <sup>16</sup>O(p,p) resonances at 3038 keV and 3473 keV, respectively, in the beam energy calibration of small accelerators. The high resolution optical microscopy method and X-ray fluorescence technique were used to characterize the targets deposited on various backing substrates. It was shown that the distribution of tungsten in the deposited layers is homogeneous and uniform. From the stoichiometric preservation of the method, the homogeneity and uniformity of the O distribution are deduced. The results indicate that the method used is a viable and effective technique for preparing high-quality nuclear targets, with significant implications for elastic backscattering experiments and other applications in nuclear physics.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1073 ","pages":"Article 170278"},"PeriodicalIF":1.5,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349050","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 : 2025-02-04DOI: 10.1016/j.nima.2025.170267
Finn Kohrell , Sam Barber , Kyle Jensen , Christopher Doss , Curtis Berger , Carl Schroeder , Eric Esarey , Florian Grüner , Jeroen van Tilborg
Successfully using electron bunches generated from Laser-Plasma Accelerators (LPAs) to drive reliable Free-Electron Lasers (FELs) requires exceptional stability of the parameters involved in the LPA interaction. On the BELLA Center’s Hundred Terawatt Undulator (HTU) System at Lawrence Berkeley National Laboratory (LBNL) we use a 100 Terawatt Ti:Sapph laser, capable of supplying 2.5 Joule, sub 40 fs pulses at 1 Hz on target, to produce 100 MeV, quasi-monoenergetic electron beams. As part of the effort to characterize and stabilize the laser pulses, a non-invasive on-shot spectral phase diagnostic was designed and commissioned on the HTU beamline. The results allow studying the direct correlations of spectral phase fluctuations to LPA and FEL parameters and chart a path towards further stabilization of the LPA process.
{"title":"Investigation of correlations between spectral phase fluctuations of the laser pulse and the performance of an LPA","authors":"Finn Kohrell , Sam Barber , Kyle Jensen , Christopher Doss , Curtis Berger , Carl Schroeder , Eric Esarey , Florian Grüner , Jeroen van Tilborg","doi":"10.1016/j.nima.2025.170267","DOIUrl":"10.1016/j.nima.2025.170267","url":null,"abstract":"<div><div>Successfully using electron bunches generated from Laser-Plasma Accelerators (LPAs) to drive reliable Free-Electron Lasers (FELs) requires exceptional stability of the parameters involved in the LPA interaction. On the BELLA Center’s Hundred Terawatt Undulator (HTU) System at Lawrence Berkeley National Laboratory (LBNL) we use a 100 Terawatt Ti:Sapph laser, capable of supplying 2.5 Joule, sub 40 fs pulses at 1 Hz on target, to produce 100 MeV, quasi-monoenergetic electron beams. As part of the effort to characterize and stabilize the laser pulses, a non-invasive on-shot spectral phase diagnostic was designed and commissioned on the HTU beamline. The results allow studying the direct correlations of spectral phase fluctuations to LPA and FEL parameters and chart a path towards further stabilization of the LPA process.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1073 ","pages":"Article 170267"},"PeriodicalIF":1.5,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143234721","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 report on the development of a low-energy positron diffraction (LEPD) experimental station for surface structure analysis using a linear electron accelerator (linac)-based slow-positron beam. LEPD is the positron counterpart of low-energy electron diffraction (LEED) and is expected to offer higher accuracy in surface structure determination compared to LEED. The station enables acquisition of LEPD – curves within a few hours. It consists of two ultra-high vacuum (UHV) chambers for LEPD measurements and sample preparation, equipped with essential tools for surface preparation and evaluation. A newly designed sample holder has been developed to be compatible with this LEPD station at SPF-A4 of the Slow Positron Facility (SPF) and the angle-resolved photoemission spectroscopy (ARPES) station at BL-13B of the Photon Factory (PF), both located at the Tsukuba campus of the Institute of Materials Structure Science (IMSS), High Energy Accelerator Research Organization (KEK). This system facilitates LEPD and ARPES measurements on the same sample under consistent surface conditions, achieved through identical preparation environments and procedures.
{"title":"Development of a linac-based LEPD experimental station for surface structure analysis and coordination with synchrotron radiation ARPES","authors":"Rezwan Ahmed , Izumi Mochizuki , Toshio Hyodo , Tetsuroh Shirasawa , Seigi Mizuno , Yoshinari Kondo , Kenichi Ozawa , Miho Kitamura , Kenta Amemiya , Bartlomiej Checinski , Jozef Ociepa , Achim Czasch , Ottmar Jagutzki , Ken Wada","doi":"10.1016/j.nima.2025.170270","DOIUrl":"10.1016/j.nima.2025.170270","url":null,"abstract":"<div><div>We report on the development of a low-energy positron diffraction (LEPD) experimental station for surface structure analysis using a linear electron accelerator (linac)-based slow-positron beam. LEPD is the positron counterpart of low-energy electron diffraction (LEED) and is expected to offer higher accuracy in surface structure determination compared to LEED. The station enables acquisition of LEPD <span><math><mi>I</mi></math></span>–<span><math><mi>V</mi></math></span> curves within a few hours. It consists of two ultra-high vacuum (UHV) chambers for LEPD measurements and sample preparation, equipped with essential tools for surface preparation and evaluation. A newly designed sample holder has been developed to be compatible with this LEPD station at SPF-A4 of the Slow Positron Facility (SPF) and the angle-resolved photoemission spectroscopy (ARPES) station at BL-13B of the Photon Factory (PF), both located at the Tsukuba campus of the Institute of Materials Structure Science (IMSS), High Energy Accelerator Research Organization (KEK). This system facilitates LEPD and ARPES measurements on the same sample under consistent surface conditions, achieved through identical preparation environments and procedures.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1073 ","pages":"Article 170270"},"PeriodicalIF":1.5,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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