高气压充氙电离室中的氙离子漂移速度测量及漂移特性研究

项目名称： 高气压充氙电离室中的氙离子漂移速度测量及漂移特性研究

项目编号： No.11205095

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 物理学II

项目作者： 王振涛

作者单位： 清华大学

项目金额： 25万元

中文摘要： 气体电离室是最早用于测量电离辐射的一种探测器，目前仍广泛应用于科研、安检、医疗等领域。气体电离室借助电离产生的离子、电子在电场作用下的漂移运动产生输出信号。离子、电子在气体中的产生、运动、转化的规律与机制是气体电离室研究中的基础问题。为提高探测效率及灵敏度，电离室往往充高压气体。但是，气体压力的提高也会影响离子的漂移特性，随着气体压力的提高，离子漂移速度会变慢，使得电离室时间响应特性变差。目前，国内外对高气压条件下离子漂移特性的研究还不是很广泛和深入。为此，本项目拟针对常用的高气压充氙电离室，研究氙离子在高压氙气中的漂移特性。采用一种新的实验测量方法，以脉冲X射线机作为射线源，通过分析实验电离室的输出电压信号来测量氙离子在高气压氙气中的漂移速度，并据此研究其漂移特性。此项研究对于更深入理解和掌握气体电离室中离子的输运特性、提高电离室时间响应性能等都具有十分重要的意义。

中文关键词： 充气电离室；氙离子；漂移速度；；

英文摘要： At present, gas-pressurized ionization chambers which have been most early employed in radiation detection, are still extensively used in many fields such as research，security check, medical treatment and etc. The output signals of the chambers are mainly arose by the drift process of the ions and electrons generated during ionization driven by the electrostatic force in the electric field. Thus, the rules and mechanisms of the generation, transportation and transformation of the ions and electrons in the gas are the basic issues in the research of ionization chamber. High-pressure gas is often adopted to fill the chambers in order to improve detection efficiency and sensitivity. However, the drift characteristic of ions is also affected by the pressure of the gas. With the raising of the gas pressure, the ions drift velocity drops and the time response characteristic becomes poor. Research on ions drift characteristic in high-pressure gas is not wide and deep enough at home and abroad. In this project, we study the xenon ions drift characteristic in high-pressure xenon ionization chamber which is widely used. A new approach of experimental measurement is suggested. A pulsed X-ray producer is employed as the radiation source. The drift velocity of xenon ions in high-pressure xenon can be measured by analyzing th

英文关键词： gas-pressurized ionization chamber；xenon ions；drift velocity；；