基于玻璃毛细管的大气环境MeV质子微束的产生与测量  

Production and measurement of MeV proton microbeams in atmospheric environment based on glass capillary

作　　者：万城亮[1] 潘俞舟 朱丽萍 李鹏飞 张浩文 赵卓彦 袁华 樊栩宏 孙文胜 杜战辉 陈乾 崔莹[1] 廖天发 魏晓慧 王天琦[6] 陈熙萌[1,7] 李公平[1] Reinhold Schuch 张红强[1,7] Wan Cheng-Liang;Pan Yu-Zhou;Zhu Li-Ping;Li Peng-Fei;Zhang Hao-Wen;Zhao Zhuo-Yan;Yuan Hua;Fan Xu-Hong;Sun Wen-Sheng;Du Zhan-Hui;Chen Qian;Cui Ying;Liao Tian-Fa;Wei Xiao-Hui;Wang Tian-Qi;Chen Xi-Meng;Li Gong-Ping;Reinhold Schuch;Zhang Hong-Qiang(School of Nuclear Science and Technology,Lanzhou University,Lanzhou 730000,China;School of Basic Medical Sciences,Lanzhou University,Lanzhou 730000,China;College of Nuclear Science and Technology,Harbin Engineering University,Harbin 150001,China;College of Science,Nantong University,Nantong 226019,China;School of Electronic Information and Electrical Engineering,Huizhou University,Huizhou 516067,China;Institute of Space Environment and Material Science,Harbin Institute of Technology,Harbin 150006,China;Center for Advanced Science of Rare Isotopes,Lanzhou University,Lanzhou 730000,China;Department of Physics,Stockholm University,Stockholm S-10691,Sweden)

机构地区：[1]兰州大学核科学与技术学院,兰州730000 [2]兰州大学基础医学院,兰州730000 [3]哈尔滨工程大学核科学与技术学院,哈尔滨150001 [4]南通大学理学院,南通226019 [5]惠州学院电子信息与电气工程学院,惠州516067 [6]哈尔滨工业大学空间环境与物质科学研究院,哈尔滨150006 [7]兰州大学稀有同位素前沿科学中心,兰州730000 [8]斯德哥尔摩大学物理系,斯德哥尔摩S-10691

出　　处：《物理学报》2024年第10期143-152,共10页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:U1732269);中央高校基本科研业务费(批准号:lzujbky-2021-sp41);广东省普通高校重点项目(批准号:2022ZDZX3028);广东省基础与应用基础研究基金(批准号:2022B1515120051);广东省教育厅重点建设学科项目(批准号:2022ZDJS055)资助的课题。

摘　　要：本文采用玻璃毛细管产生了大气环境中工作的2.5 MeV质子外束微束,并对束斑直径及能量分布随玻璃毛细管与束流方向之间角度(倾角)变化进行测量.测量结果表明,在玻璃毛细管轴向与束流方向一致时(倾角为0°),产生的微束中存在保持初始入射能量的直接穿透部分以及散射部分,其中直接穿透的质子占比最大,束斑直径也最大.随着玻璃毛细管倾角的增大,当其大于几何张角时,束斑直径变小,产生的微束全部为能量减小的散射部分,直接穿透质子消失.我们对质子在玻璃毛细管内传输时的内壁散射过程进行了模拟计算及离子轨迹分析,发现大角度的散射部分决定了形成的外束微束斑外围轮廓,而束斑中心区域由不与毛细管内壁产生任何作用的直接穿透离子构成,其大小由玻璃毛细管出口直径以及几何容许张角决定.采用玻璃毛细管产生的外束微束具有产生简单廉价,微束区域定位简单的特点,有望在辐射生物学、医学、材料等领域得到广泛应用.Traditionally,ion microbeam is produced by focusing or/and collimating to reduce the beam size to submicron level.The traditional setup for producing the microbeam consists of an expensive focusing and collimating system with a large space,based on electromagnetic fields.Meanwhile,the microbeam obtained through pure collimation of metal micro-tubes is limited by the fabrication processing,i.e.the size of beam spot is largely limited to a few microns and its manufacture is not as simple as that of a glass capillary.Inspired by early studies of the guiding effect,the use of inexpensive and easy-to-make glass capillaries as the tool for ion external microbeam production has become a new direction.In this work,we use a glass capillary with an open outlet(108μm in diameter),which serves as a vacuum differential and collimating component,to produce a 2.5 MeV-proton microbeam directly from the linear accelerator into the atmosphere for measurements.We measure the beam spot diameter and energy distribution of the microbeam as a function of the tilt angle of the capillary.We also conduct calculations and ion trajectory analysis on the scattering process of 2.5 MeV protons on the inner walls.The measurement results show that when the tilt angle is around 0°,there are a direct transmission part that maintains the initial incident energy,and a scattering part with the energy loss in the microbeam.It is found that the proportion of directly transmitted protons and the beam spot size are highest near zero tilt angle.As the tilt angle increases,the beam spot diameter decreases;when the tilt angle is greater than the geometric angle,all the microbeams come from the scattering with the energy loss.The simulation combined with the ion trajectory analysis based on the scattering process can explain the experimental results.It is found that the large angle scattering determines the entire external microbeam spot,and the central region of the beam spot is composed of directly penetrating ions,whose size is determined by the geometr

关 键 词：离子外束微束 MeV质子 锥形玻璃毛细管 

分 类 号：O552.421[理学—热学与物质分子运动论]