强流脉冲质子束轰击^(19)F靶产生6—7MeV准单能脉冲γ射线初步实验研究  

Preliminary experimental researches on 6—7 MeV quasi-monoenergetic pulsed γ-rays generation via intense pulsed proton beam striking ^(19)F target

作　　者：杨海亮[1] 邱爱慈[1] 孙剑锋[1] 何小平[1] 张嘉生[1] 汤俊萍[1] 王海洋[1] 许日[1] 彭建昌[1] 任书庆[1] 李鹏[1] 杨莉[1] 黄建军[1] 张国光[1] 欧阳晓平[1] 

机构地区：[1]西北核技术研究所,西安710024

出　　处：《核技术》2004年第3期188-192,共5页Nuclear Techniques

基　　金：国家自然科学基金 (10375048) ;国防科技预研基金资助课题

摘　　要：给出了利用PIN半导体探测器和ST401塑料闪烁体配合光电倍增管测量的强流脉冲质子束轰击含F19核素的靶产生的6—7MeV准单能脉冲γ射线的初步实验结果。理论上计算了质子束轰击C2F4靶产生的准单能脉冲γ射线产额和核反应截面随入射质子能量的变化曲线,提出了采用质子束传输法分离和降低轫致辐射干扰的方法,利用ST401配合光电倍增管和PIN半导体探测器测量了质子传输不同距离后轰击C2F4靶产生的6—7MeV准单能脉冲γ射线谱以及相对于轫致辐射的时间延迟数据,并根据飞行时间确定了束流峰值时刻的质子能量,还通过实验验证了Cu、Cr和不锈钢靶及其中所含的杂质不能产生明显的其它能量的γ射线干扰。The 6—7 MeV quasi-monoenergetic pulsed γ -rays were produced on the FLASH Ⅱ accelerator. The pulsed γ -rays were generated via intense pulsed high power proton beam striking F target and measured with the 19 PIN semiconductor detectors and ST401 plastic scintillators. The yield of the quasi-monoenergetic pulsed γ photons from the 19F ( p, αγ ) 16 Ο reaction was calculated. By placing the target far enough downstream so that the time-of-flight was greater than the duration of the diode bremsstrahlung pulse, the quasi-monoenergetic pulsed γ -rays were discriminated from the diode bremsstrahlung, and the bremsstrahlung was depressed due to extending the distance between detector and diode. The quasi-monoenergetic pulsed γ -rays and their time delay were measured with ST401 plastic scintillator photomultiplier and the PIN semiconductor detector at various transmission distances. The proton energy at the beam current peak time was calculated by time-of-flight method. It is demonstrated by a series of experiments that the Cu, Cr, stainless steel target and the impurity in the target would not produce γ -ray interferences with other energies.

关 键 词：准单能脉冲γ射线 强流脉冲质子束 PIN探测器 光电倍增管 飞行时间 轫致辐射 

分 类 号：O571.42[理学—粒子物理与原子核物理] O571.32[理学—物理]