摘要
介绍了一种基于全永磁微波离子源钛自成靶技术的紧凑型氘氘(D-D)中子源,其设计中子产额为 1×109 s-1.该D-D中子源已经进行了800 h以上的测试,系统可重复稳定运行.早期测试结果显示,系统打火频率高、中子产额低,长时间放电后反向电子会烧蚀Al2O3 陶瓷窗,导致微波耦合困难,氘等离子体无法点亮.通过在等离子体腔室中添加氮化硼(BN)保护片以及在钛靶与高压电极之间增加电子抑制电阻,有效抑制了Al2O3 陶瓷窗的损伤.通过对等离子体电极孔径的优化和降低腔室压力,降低了打火频率,提高了中子的产额.系统优化后,氘离子能量为 70 keV、束流强度为 5 mA时,中子产额达到了 2.0×108 s-1.在氘离子能量为 97 keV、束流强度为6.6 mA时,系统中子产额达到5.2×108 s-1.
Abstract
A compact deuterium-deuterium(D-D)neutron source system with a designed neutron yield of 1×109 s-1 based on permanent magnet microwave ion source and titanium(Ti)drive-in target technique is described.This neutron source system has been tested for more than 800 hours,and it can operate repeatedly and stably at present.The early test re-sults show that the system has high ignition frequency and low neutron yield.And the D plasma cannot discharge after long time operation due to the Al2O3 ceramic window which used for the microwave feed being ablated by the emitted secondary electrons.The damage of Al2O3 ceramic window was effectively inhibited by adding a BN protection plate in the plasma chamber and an electron suppression resistance between the Ti target and the high voltage electrode in the vacuum chamber of the neutron source system.By optimizing the structure of the plasma electrode and increasing the vacuum degree,the igni-tion frequency of the system is reduced,and the neutron yield is increased.The neutron yield is up to 2.0×108 s-1 during the 5 mA and 70 keV D ions bombarding the Ti target.When the deuterium ion energy is 97 keV and the D beam intensity is 6.6 mA,the neutron yield of the system reaches 5.2×108 s-1.
基金项目
国家自然科学基金(12105135)
国家自然科学基金(12005145)
国家自然科学基金(12305200)
安徽省自然科学基金(2308085MA22)
合肥综合性国家科学中心能源研究院(安徽省能源实验室)项目(21KZS202)
合肥综合性国家科学中心能源研究院(安徽省能源实验室)项目(21KZS208)
中央高校基本科研业务费专项(NJ2022019-3)
NETL
NSTL
万方数据