中国原子能科学研究院的5SDH-2串列加速器于1996年从美国国家静电公司引进。其主要配置参数是端电压100KV-1.7MV，对于单电荷粒子可加速的最高能量为3.4MeV。两个离子源，一个是溅铯离子源，一个是TORVIS离子源，TORVIS离子源是气体离子源，主要产生H^-，D^-和He^-，三种粒子，注入端H^-，D^-粒子流强可达250μA，He^-可达50μA。可以产生脉冲束，脉冲频率4MHZ~0.625MHz，脉冲宽度1~2ns。4MHz时，靶上质子束流约10μA.

加速器高压产生示意图

利用⁷Li（p,n），T（p, n），T（d, n）核反应，建立了国内唯一的单能中子参考辐射场，能量点包括144keV，250keV，565keV，1.2MeV，5MeV，14.8MeV，19MeV，中子发射率10⁶~10⁸/s，可用于中子核数据测量、中子探测器性能及中子计量仪表的校准等。

中国原子能科学研究院作为国际计量局咨询委员会电离辐射分会的观察员多次代表中国参加国际比对。

2001年单能快中子国际比对结果

Theneutronsourcebasedon 5SDH-2 pelletron accelerator

5SDH-2 pelletron accelerator made in National Electrostatics Corporation of USA  was installed in CIAE in 1996. The terminal voltage is from 100kV~1.7MV, the maximum energy is up to 3.4MeV for single charge particle. The two ion sources is equipped, one is SNICS source, the other is TORVIS source. The TORVIS can produce three kinds of ion which are respectively proton, deuterium and helium. The beam current is up to 250μA for proton and deuterium, 50μA for deuterium at the injector.Inpulsedmode, the range of frequency is from 4MHz~0.625MHz, the pulse width is about 1ns~2ns for proton and deuterium, the average beam current on the target is about 10μA at 4MHz for proton.

The skeptic of terminal generation of the accelerator

The only mono-energitic reference field was built in China in use of the reactions including ⁷Li（p,n），T（p, n）and T（d, n）based on the accelerator. The energy points are 144keV，250keV，565keV，1.2MeV，5MeV，14.8MeV，19MeV respectively.

The neutron emission rate isabout 10⁶~10⁸/s. It will meet neutron nuclear data measurement, testing of neutron detector and routine calibration of neutron dosimeters.

CIAEas an observer anticipated internal key comparison of mono-energitic neutron organized by CCRI of BIPMon behalf of China several times. 

The results of international comparison of mono-energetic fast neutron in 2001

刘蕴韬 研究员   

中国原子能科学研究院

E-mail：ytliu@ciae.ac.cn