Donghyun Kwak , Seok-Ho Moon , Kyoungho Tshoo , Gidong Kim , Jang Won Kwon , Min Jae Kim , Kyounghun Yoo , Eunhun Im , Sangjin Lee , Hyung Jin Kim , Hyungjoo Woo , Junyeong Jeong , Cheolmin Ham , Moses Chung
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The developed pre-bunching system combines a fast chopper with a Double Gap Buncher (DGB). The fast chopper utilizes the existing slow chopper electrodes by adapting them to generate pulsed beams with controlled repetition rates. Meanwhile, the DGB reduces the pulse length to less than one Radio Frequency Quadrupole (RFQ) cycle at the RFQ entrance, thereby minimizing the formation of satellite bunches during RFQ acceleration. Simulations using the SIMION code validated the pre-bunching system’s performance prior to beam commissioning. Additionally, we have developed RF voltage-boosting circuits to supply high-voltage RF to both the fast chopper and the DGB. Following the design and development phase, we performed beam commissioning with Ar<span><math><msup><mrow></mrow><mrow><mi>8+</mi></mrow></msup></math></span> ion beams, which successfully demonstrated the generation of single bunches for the first time at RAON, confirming the performance of the pre-bunching system.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1080 ","pages":"Article 170805"},"PeriodicalIF":1.4000,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Development and commissioning of the pre-bunching system at RAON\",\"authors\":\"Donghyun Kwak , Seok-Ho Moon , Kyoungho Tshoo , Gidong Kim , Jang Won Kwon , Min Jae Kim , Kyounghun Yoo , Eunhun Im , Sangjin Lee , Hyung Jin Kim , Hyungjoo Woo , Junyeong Jeong , Cheolmin Ham , Moses Chung\",\"doi\":\"10.1016/j.nima.2025.170805\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>The low-energy experimental systems at the Rare isotope Accelerator complex for ON-line experiments (RAON) consist of the Korea Broad Acceptance Recoil spectrometer and Apparatus (KoBRA) and the Nuclear Data Production System (NDPS). Controlling the beam repetition rate is essential for Time-of-Flight (TOF) experiments because too frequent primary beam bunches can cause overlapping of secondary beam bunches, leading to uncertainty in the TOF measurements of secondary beam particles. This study presents the design, fabrication, and commissioning results of a pre-bunching system at RAON to manage the beam repetition rate. The developed pre-bunching system combines a fast chopper with a Double Gap Buncher (DGB). The fast chopper utilizes the existing slow chopper electrodes by adapting them to generate pulsed beams with controlled repetition rates. Meanwhile, the DGB reduces the pulse length to less than one Radio Frequency Quadrupole (RFQ) cycle at the RFQ entrance, thereby minimizing the formation of satellite bunches during RFQ acceleration. Simulations using the SIMION code validated the pre-bunching system’s performance prior to beam commissioning. 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Following the design and development phase, we performed beam commissioning with Ar<span><math><msup><mrow></mrow><mrow><mi>8+</mi></mrow></msup></math></span> ion beams, which successfully demonstrated the generation of single bunches for the first time at RAON, confirming the performance of the pre-bunching system.</div></div>\",\"PeriodicalId\":19359,\"journal\":{\"name\":\"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment\",\"volume\":\"1080 \",\"pages\":\"Article 170805\"},\"PeriodicalIF\":1.4000,\"publicationDate\":\"2025-07-04\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0168900225006060\",\"RegionNum\":3,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"INSTRUMENTS & INSTRUMENTATION\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0168900225006060","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"INSTRUMENTS & INSTRUMENTATION","Score":null,"Total":0}
Development and commissioning of the pre-bunching system at RAON
The low-energy experimental systems at the Rare isotope Accelerator complex for ON-line experiments (RAON) consist of the Korea Broad Acceptance Recoil spectrometer and Apparatus (KoBRA) and the Nuclear Data Production System (NDPS). Controlling the beam repetition rate is essential for Time-of-Flight (TOF) experiments because too frequent primary beam bunches can cause overlapping of secondary beam bunches, leading to uncertainty in the TOF measurements of secondary beam particles. This study presents the design, fabrication, and commissioning results of a pre-bunching system at RAON to manage the beam repetition rate. The developed pre-bunching system combines a fast chopper with a Double Gap Buncher (DGB). The fast chopper utilizes the existing slow chopper electrodes by adapting them to generate pulsed beams with controlled repetition rates. Meanwhile, the DGB reduces the pulse length to less than one Radio Frequency Quadrupole (RFQ) cycle at the RFQ entrance, thereby minimizing the formation of satellite bunches during RFQ acceleration. Simulations using the SIMION code validated the pre-bunching system’s performance prior to beam commissioning. Additionally, we have developed RF voltage-boosting circuits to supply high-voltage RF to both the fast chopper and the DGB. Following the design and development phase, we performed beam commissioning with Ar ion beams, which successfully demonstrated the generation of single bunches for the first time at RAON, confirming the performance of the pre-bunching system.
期刊介绍:
Section A of Nuclear Instruments and Methods in Physics Research publishes papers on design, manufacturing and performance of scientific instruments with an emphasis on large scale facilities. This includes the development of particle accelerators, ion sources, beam transport systems and target arrangements as well as the use of secondary phenomena such as synchrotron radiation and free electron lasers. It also includes all types of instrumentation for the detection and spectrometry of radiations from high energy processes and nuclear decays, as well as instrumentation for experiments at nuclear reactors. Specialized electronics for nuclear and other types of spectrometry as well as computerization of measurements and control systems in this area also find their place in the A section.
Theoretical as well as experimental papers are accepted.