Journal of the Korean Physical Society最新文献_第10页

Comparative analysis of InAsP and InGaAs photodetectors for SWIR applications: photoreflectance approach and simulations 用于SWIR应用的InAsP和InGaAs光电探测器的比较分析：光反射方法和模拟

IF 0.9 4区物理与天体物理

Journal of the Korean Physical Society Pub Date : 2025-03-18 DOI: 10.1007/s40042-025-01321-w

S. Bahareh Seyedein Ardebili, Behnam Zeinalvand Farzin, Jong Su Kim, Sang Jun Lee

引用次数: 0

Accelerating cell design optimization for separated drift tube linac in KOMAC KOMAC分离漂移管直线加速器加速池设计优化

IF 0.9 4区物理与天体物理

Journal of the Korean Physical Society Pub Date : 2025-03-17 DOI: 10.1007/s40042-025-01346-1

Sungbin Park, Seunghyun Lee, Han-Sung Kim, Hyeok-Jung Kwon

引用次数: 0

Dust-ion-acoustic solitary and shock waves in a multi-ion dusty plasma with Kaniadakis distributed nonthermal electrons 多离子尘埃等离子体中具有卡尼达基斯分布的非热电子的尘声孤波和激波

IF 0.8 4区物理与天体物理

Journal of the Korean Physical Society Pub Date : 2025-03-13 DOI: 10.1007/s40042-025-01320-x

O. Rahman

引用次数: 0

Brazing characteristics of vertical joints with silver copper eutectic alloy Ag72Cu28 for RFQ section brazing stage 银铜共晶合金Ag72Cu28垂直接头RFQ截面钎焊阶段的钎焊特性

IF 0.9 4区物理与天体物理

Journal of the Korean Physical Society Pub Date : 2025-03-13 DOI: 10.1007/s40042-025-01333-6

Kyung Hyun Kim, Jung Goo Hong

{"title":"Brazing characteristics of vertical joints with silver copper eutectic alloy Ag72Cu28 for RFQ section brazing stage","authors":"Kyung Hyun Kim, Jung Goo Hong","doi":"10.1007/s40042-025-01333-6","DOIUrl":"10.1007/s40042-025-01333-6","url":null,"abstract":"<div><p>A radio-frequency quadrupole (RFQ) is a critical component in particle accelerator technology, and section brazing is a crucial fabrication process in this context. This study investigates the brazing characteristics of vertical joints created using Ag72Cu28 metal filler in a high-vacuum environment. Experimental specimens were prepared with copper plates and brazed at temperatures ranging from 778 to 805° C to analyze the melting behavior of the filler. X-ray computerized tomography (CT) scans revealed that the filler begins to melt at 782° C and that complete melting occurs at 784° C. It was found that maintaining temperatures of above 780° C for at least 17 min ensures optimal bonding, while temperatures below this can result in incomplete melting and potential vacuum leaks. Conversely, excessively high temperatures can cause filler overflow and require additional machining. This study provides critical insights regarding the precise temperature control required for successful RFQ section brazing, addressing the challenges of vacuum leaks and incomplete filler melting. These findings offer practical guidelines related to the minimum brazing temperature and brazing time for improving RFQ manufacturing reliability, particularly for vertical joint configurations.</p></div>","PeriodicalId":677,"journal":{"name":"Journal of the Korean Physical Society","volume":"87 on","pages":"892 - 901"},"PeriodicalIF":0.9,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145190210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0

Dosimetry method for biomedical research using KoBRA beamline and ISOL at RAON 在RAON使用KoBRA光束线和ISOL进行生物医学研究的剂量测定方法

IF 0.9 4区物理与天体物理

Journal of the Korean Physical Society Pub Date : 2025-03-13 DOI: 10.1007/s40042-025-01336-3

Chae-Eon Kim, Ui-Jung Hwang, Yoonsun Chung, Taeksu Shin, Se Byeong Lee

引用次数: 0

Fermi level pinning mitigation in GaN Schottky contacts via UV/O3-treated interfaces 通过UV/ o3处理界面的GaN肖特基触点中的费米能级抑制

IF 0.8 4区物理与天体物理

Journal of the Korean Physical Society Pub Date : 2025-03-11 DOI: 10.1007/s40042-025-01335-4

Goeun Ham, Sumin Suk, Kwangeun Kim

{"title":"Fermi level pinning mitigation in GaN Schottky contacts via UV/O3-treated interfaces","authors":"Goeun Ham, Sumin Suk, Kwangeun Kim","doi":"10.1007/s40042-025-01335-4","DOIUrl":"10.1007/s40042-025-01335-4","url":null,"abstract":"<div><p>GaN has recently emerged as a prominent material for power electronics due to its wide bandgap properties. However, challenges related to interface states at metal/GaN junction cause deviations in device characteristics such as leakage current and breakdown voltage. The interface defects induce Fermi level pinning (FLP) at the metal–GaN interface and significantly affect the electrical performance of devices. In this study, we investigated the impact of ultraviolet/ozone (UV/O<sub>3</sub>) treatment on the interface characteristics of metal/GaN junctions, by mitigating FLP phenomenon. The electrical properties of the samples were analyzed after applying UV/O<sub>3</sub> treatment to the GaN surface, followed by the separate deposition of Pt and Ni. Through I–V and C–V curves analysis, we observed a reduction in leakage current along with changes in breakdown voltages and Schottky barrier heights. Our findings demonstrate that the oxide layer formed through the UV/O₃ treatment enhances the interface passivation, reducing defect states and improving device performance. This work provides insights into controlling the properties at the metal–GaN interfaces and elucidating the mechanism of mitigating FLP.</p></div>","PeriodicalId":677,"journal":{"name":"Journal of the Korean Physical Society","volume":"86 9","pages":"918 - 923"},"PeriodicalIF":0.8,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143896764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0

Development of a system for on-site dosimetry audit of high-dose-rate brachytherapy 高剂量率近距离放射治疗现场剂量学审核系统的开发

IF 0.8 4区物理与天体物理

Journal of the Korean Physical Society Pub Date : 2025-03-10 DOI: 10.1007/s40042-025-01331-8

Hyeok-Jun Gwon, Wonho Lee, Sang-Hyoun Choi, Gyu-Seok Cho, Soon Sung Lee, Sun-Boong Hwang, Kum Bae Kim

引用次数: 0

Anomaly detection in KOMAC high-power systems using transformer-based conditional variational autoencoder 基于变压器的条件变分自编码器在KOMAC大功率系统中的异常检测

IF 0.9 4区物理与天体物理

Journal of the Korean Physical Society Pub Date : 2025-03-10 DOI: 10.1007/s40042-025-01339-0

Gi-Hu Kim, Hae-Seong Jeong, Han-Sung Kim, Hyeok-Jung Kwon, Dong-Hwan Kim

{"title":"Anomaly detection in KOMAC high-power systems using transformer-based conditional variational autoencoder","authors":"Gi-Hu Kim, Hae-Seong Jeong, Han-Sung Kim, Hyeok-Jung Kwon, Dong-Hwan Kim","doi":"10.1007/s40042-025-01339-0","DOIUrl":"10.1007/s40042-025-01339-0","url":null,"abstract":"<div><p>This study applies a transformer-based conditional variational autoencoder (T-CVAE) model for anomaly detection in pulse waveform signals from the High Voltage Converter Modulator (HVCM) and Klystron at the Korea Multipurpose Accelerator Complex (KOMAC). Building upon prior work using CVAE models for anomaly detection in Spallation Neutron Source (SNS) accelerators, the T-CVAE model was tailored to the specific characteristics of KOMAC data by optimizing hyperparameters and leveraging transformer-based architectures for enhanced feature extraction. Experimental results demonstrate that the model effectively learns the distribution of normal signals, as validated through boxplots, the receiver operation characteristics (ROC) curve and kernel density estimation (KDE) analyses. Anomalies are detected through significant reconstruction loss differences between normal and abnormal signals. By reliably identifying pre-fault conditions, the proposed system offers a promising approach to improving operational reliability and minimizing unplanned downtime in KOMAC's proton linear accelerator.</p></div>","PeriodicalId":677,"journal":{"name":"Journal of the Korean Physical Society","volume":"87 on","pages":"883 - 891"},"PeriodicalIF":0.9,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145190216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0

Influence of stopping power tables on carbon-ion range simulations in Geant4 停止功率表对Geant4中碳离子范围模拟的影响

IF 0.9 4区物理与天体物理

Journal of the Korean Physical Society Pub Date : 2025-03-10 DOI: 10.1007/s40042-025-01334-5

Sung Hyun Lee, Yoshiyuki Hirano, Jaeman Son, Sung Young Lee, Bitbyeol Kim, Jong Min Park, Kyung Su Kim, Seonghee Kang, Chang Heon Choi, Hyeongmin Jin

{"title":"Influence of stopping power tables on carbon-ion range simulations in Geant4","authors":"Sung Hyun Lee, Yoshiyuki Hirano, Jaeman Son, Sung Young Lee, Bitbyeol Kim, Jong Min Park, Kyung Su Kim, Seonghee Kang, Chang Heon Choi, Hyeongmin Jin","doi":"10.1007/s40042-025-01334-5","DOIUrl":"10.1007/s40042-025-01334-5","url":null,"abstract":"<div><p>This study investigated the impact of different stopping power (SP) tables on the range of therapeutic energy of carbon ions in water. Four SP tables were considered: those provided by ICRU reports 73 and 90, the stopping and range of ions in matter (SRIM) software, and the MSTAR program. The theoretical range calculations were performed based on a continuous slowing-down approximation for each SP table. Range calculations were performed using the Geant4 Monte Carlo simulation toolkit. In the Geant4 simulations, the Bragg curve was generated solely by varying the input SP table while keeping the other simulation parameters constant. The results demonstrate a significant variation in the range of carbon ions across different SP tables within the therapeutic energy range, with differences of up to 6 mm in both the theoretical and simulated calculations. Therefore, when simulating the Bragg curve of therapeutic energy carbon ions using Monte Carlo simulations, it is crucial to acknowledge the potential for several millimeters of variation in the Bragg peak position, depending on the chosen SP table. Furthermore, a careful comparison of the simulated Bragg peak positions with experimentally measured data across the entire therapeutic energy range is recommended.</p></div>","PeriodicalId":677,"journal":{"name":"Journal of the Korean Physical Society","volume":"87 on","pages":"855 - 859"},"PeriodicalIF":0.9,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145190213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0

Design improvements of electron gun for PAL klystron PAL速调管电子枪的设计改进

IF 0.9 4区物理与天体物理

Journal of the Korean Physical Society Pub Date : 2025-03-10 DOI: 10.1007/s40042-025-01338-1

S. J. Park, C. K. Min, Y. G. Park, S. D. Jang, G. Y. Jang, H. S. Shin

{"title":"Design improvements of electron gun for PAL klystron","authors":"S. J. Park, C. K. Min, Y. G. Park, S. D. Jang, G. Y. Jang, H. S. Shin","doi":"10.1007/s40042-025-01338-1","DOIUrl":"10.1007/s40042-025-01338-1","url":null,"abstract":"<div><p>Several prototype S-band pulsed klystrons for use at the Pohang Accelerator Laboratory (PAL) have been developed by a domestic company in collaboration with PAL. These klystrons successfully achieved the required RF output power at a low repetition rate (< 30 Hz) but suffered from gun arcing when operated at 60 Hz, which is the repetition rate required for the PAL-XFEL. Post-mortem inspection revealed that the arcing spots on the focusing electrode (Wehnelt) were not located at the regions of maximum electric field. Particle trajectory simulations in the electron gun region suggest that the initial arcing is triggered by electron emission and followed by clump-induced breakdown processes. In addition, vacuum breakdown can be initiated from the so-called triple point (TP) at the lower end of the ceramic insulator, where a negative potential is applied during high-voltage (HV) operation. Further numerical simulations confirmed that electrons emitted from this TP can travel along the ceramic surface, undergo multiplication, and eventually cause breakdown near the anode housing. Based on these findings, we propose design improvements—most notably enhanced cleaning and polishing procedures as well as an added electric field shield near the TP—to suppress vacuum breakdown at higher repetition rates (e.g., 60 Hz). Initial high-voltage (HV) processing data show that the improved gun design significantly reduces arcing events, enabling stable klystron operation.</p></div>","PeriodicalId":677,"journal":{"name":"Journal of the Korean Physical Society","volume":"87 on","pages":"860 - 867"},"PeriodicalIF":0.9,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145190214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0