~(239)Pu α 粒子的微剂量谱和径向剂量分布

用大容积（６０ｍｍ×８０ｍｍ）的圆柱型流气式组织等效正比计数器测定了２３９Ｐｕα粒子的微剂量谱和径向剂量分布。α粒子束在无窗的情况下直接穿入正比计数器，由离子穿过而发生能量沉积的机率Ｒｂ为１。测量结果证实：沿α粒子径迹由单次事件沉积的剂量平均比能ｚ１Ｄ（Ｇｙ）与距径迹核径向距离ｂ（μｍ）之间完全符合ｚ１Ｄ＝ａｂ－２的函数关系，同时给出了求出最大径向距离（ｐｅｎｕｍｂｒａ）的方法。Microdsimetric spectra and radial dose distribution of 239 Pu α particles were measured by the cylindrical flowing tissue equivalent proportional counter with larger volume. Because of the best collimated beam traverse in TEPC (tissue equivalent preportional courreer), the probability of energy deposition per ion traversal R b is 1. The measured dose mean specific energy z 1D from single event varies strictly in accordance with formula z 1D = ab -2 , b is the radi...国家自然科学基

用圆柱型流气式组织等效正比计数器测定α粒子微剂量谱

研制并调试了圆柱型流气式组织等效正比计数器；装配了组织等效气体的配气系统斥ｖ用该装置测定了２３９Ｐｕα粒子的微剂量谱。A cylindrical flowing tissue equivalent proportional counter was made and adjusted. The tissue equivalent gas providing system and the electronic system designed for the CFTEPC were described. The microdosimetric spectra of α particles from 239Pu in TE and CH4 gases were measured.国家自然科学基

~(252)Cfα粒子的微剂量谱和径向剂量分布

用大容积(φ60mm×80mm)的圆柱型流气式组织等效正比计数器测定了~(252)Cfα粒子的微剂量谱和径向剂量分布.α粒子束在无窗的情况下直接穿入正比计数器发生能量沉积的机率R_b为1.测量结果证实:沿α粒子径迹由单次事件沉积的剂量平均比能z_(1D)(Gy)与距径迹核径向距离b(μm)之间符合z_(1D)=ab~(-x)的函数关系,当b<0.6482μm时,α=0.328,x=1.7;当b≥0.6482μm时,α=0.288, x=2.给出了求最大径向距离的方法.Microdosimetric spectra and radial dose distribution of 252 Cf a particles were measured by a large volume cylindrical flowing tissue-equivalent proportional counter(TEPC). Because a particles enter into the TEPC without a window, the probability of energy deposition per ion Rb is 1. The measured dose-mean specific energy z1D(Gy) from single-event varies with b the radial distance from the track core, according to the formula z1D=ab-x. where a = 0.328 and x=1.7 when b<0.6482 μm. and a = 0.288 and x = 2 ...国家自然科学基金资

电解法制备高纯度~(18)O_2

采用自行设计制造的石英玻璃电解装置,以重氧重水为原料,通过碱性介质电解法进行了18O气体的制备,在原料重氧重水18O的摩尔分数>80%条件下,最终制得18O气体中18O2摩尔分数达63.66%,表明整个电解系统气密性良好。此外,制得的气体能够满足电子回旋共振离子源提供18O重离子束的实验要求