Characteristics of proton beams and secondary neutrons arising from two different beam nozzles

详细信息    查看全文

• 作者：Yeon-Gyeong Choi ; Yu-Seok Kim
• 关键词：Proton ; Cyclotron ; PIXE/PIGE ; Nozzle ; PHITS
• 刊名：Journal of the Korean Physical Society
• 出版年：2015
• 出版时间：October 2015
• 年：2015
• 卷：67
• 期：8
• 页码：1324-1327
• 全文大小：299 KB
• 参考文献：[1]Md. Hasnat Kabir, ph. D. thesis, Kochi University, 2007.
  [2]M. E. Fedi et al. Nucl. Instrum. Meth. Phys. Res. B. 189, 56 (2002).CrossRef ADS
  [3]S.-H. Park and Y.-S. Kim, J. Korean Phys. Soc. 63, 1291 (2013).CrossRef ADS
  [4]F. Mathis et al. Nucl. Instrum. Meth. Phys. Res. B. 240, 532 (2005).CrossRef ADS
  [5]G. W. Grime et al. Nucl. Instrum. Meth. Phys. Res. B. 181, 66 (2001).CrossRef ADS
  [6]N. Matsuda et al., the Particle and Heavy Ion Transport code System (PHITS) version 2.64 (RIST, Japan, 2013).
  [7]W. Loveland et al., Modern Nuclear Chemistry (John Wiley & Sons, Inc., New Jersey, 2006), p. 20.
  
• 作者单位：Yeon-Gyeong Choi (1)
  Yu-Seok Kim (1)
  
  1. Department of Energy & Environment Engineering, Dongguk University, Gyeongju, 38066, Korea
  
• 刊物主题：Physics, general; Theoretical, Mathematical and Computational Physics; Particle and Nuclear Physics;
• 出版者：Springer Netherlands
• ISSN：1976-8524

文摘

A tandem or a Van de Graaff accelerator with an energy of 3 MeV is typically used for Proton Induced X-ray Emission (PIXE) analysis. In this study, the beam line design used in the PIXE analysis, instead of the typical low-energy accelerator, was used to increase the production of isotopes from a 13-MeV cyclotron. For the PIXE analysis, the proton beam should be focused at the target through a nozzle after degrading the proton beams energy from 13 MeV to 3 MeV by using an energy degrader. Previous studies have been conducted to determine the most appropriate material for and the thickness of the energy degrader. From the energy distribution of the degraded proton beam and the neutron occurrence rate at the degrader, an aluminum nozzle of X thickness was determined to be the most appropriate nozzle construction. Neutrons are created by the collision of 3-MeV protons in the nozzle after passage through the energy degrader. In addition, a proton beam of sufficient intensity is required for a non-destructive PIXE analysis. Therefore, if nozzle design is to be optimized, the number of neutrons that arise from the collision of protons inside the nozzle, as well as the track direction of the generated secondary neutrons, must be considered, with the primary aim of ensuring that a sufficient number of protons pass through the nozzle as a direct beam. A number of laboratories are currently conducting research related to the design of nozzles used in accelerator fields, mostly medical fields. This paper presents a comparative analysis of two typical nozzle shapes in order to minimize the loss of protons and the generation of secondary neutrons. The neutron occurrence rate and the number of protons that pass through the nozzle were analyzed by using a Particle and Heavy Ion Transport code System (PHITS) program in order to identify the nozzle that generated the strongest proton beam.