氦喷嘴激光飞行时间质谱仪系统传输效率的测定  

Measurement of the Transmission Efficiency of He-Jet Laser Time-of-Flight Mass Spectrometer

作　　者：程鸿兴[1] 庞文宁[1] 尚仁成[1] 张伟 塔拉 肖渊[1] 徐四大[1] 赵之正[2] 罗亦孝[2] 

机构地区：[1]清华大学物理系,北京100084 [2]中国科学院近代物理研究所,兰州730000

出　　处：《高能物理与核物理》1999年第3期244-249,共6页High Energy Physics and Nuclear Physics

基　　金：国家自然科学基金;国家教委博士点基金

摘　　要：建立了一套氦喷嘴激光飞行时间质谱仪系统并进行了离线模拟研究．其工作原理是：首先在原子化室蒸发产生样品气态原子来模拟核反应产物，然后利用氦气传输和氦喷嘴技术，使样品原子形成准直原子束与激光作用．通过激光共振激发电离实现原子序数Z的选择，再利用飞行时间质谱技术来确定原子量A，实现样品原子的分离与鉴别．通过用24Na的放射性测量的方法对谱仪系统效率进行了研究，其传输效率约为17％．A He-jet laser bine-of-flight (TOF) mass spectrometer system is built. The sample atoms evaporated in the atomization chamber are used to simulate the reaction products. The sample atoms are transferred by helitim gas trough a thin capillary.After passing through a skimmer, the sample atoms are formed into a neutral atom stream.A two-or three-color laser beams perpendicular to the atom jet is used to excite and ionize the atomes multi-steply. Then a pulsed electrical field pulls the ionized atoms to the TOF mass spectrometer. By this processing, the (Z, A) values of the sample atoms can be determined precisely. The efficiency of the spectrometer is studied by measuring the radioactivity of 24Na atoms. The transmission efficiency consists of two parts, the transportation efficiency and the efficiency of laser resonance ionization. The transportation efficiency is determined to be about 17%.

关 键 词：离子源 氦喷嘴 飞行时间质谱仪 传输效率 原理 

分 类 号：TL817.8[核科学技术—核技术及应用]