非蒸散型吸气剂泵(NEG)对N_(2)气的抽气特性研究

Pumping Characteristics of N_(2) by Non-Evaporable Getter Pumps

非蒸散型吸气剂泵(NEG)是采用过渡族金属材料的吸气特性制作成的真空泵,用于超高/极高真空环境的获得及气体的纯化等方面。本文研制出吸气剂泵性能测试系统,研究了非蒸散型吸气剂泵对N_(2)气的抽气特性,分析了影响抽气性能的因素。研制的系统采用标准流量抽速测试方法,采用固定流导法流量计提供(10^(-5)~10^(-8))Pam^(3)/s的标准气体流量,可在测试罩内获得(10^(-2)~10^(-5))Pa的气体压力下实现抽速测试。实验结果表明,NEG泵激活后处于最佳抽气状态,当抽速下降之后可在超高真空条件下放置一段时间将抽速恢复至初始状态,但泵的整体抽气性能发生一定变化;当泵连续抽气时,抽速随着吸气量的增大而逐渐减小,随着泵抽气压力的增大而减小。

Non-evaporable getter pump(NEG)is a vacuum pump made of the sorption characteristics of transition group metal materials,which is used for obtaining ultra-high/extremely high vacuum environments and gas purification.In this paper,a performance test system for getter pump is developed,the pumping characteristics of non-evaporable getter pump for N_(2) gas are studied,and the factors affecting the pumping performance are analyzed.The developed system adopts the standard flow method to test the pumping speed,and provides(10^(-5)~10^(-8))Pam^(3)/s standard gas flow rate by constant conductance flowmeter,which can achieve pumping speed test under the gas pressure of(10^(-2)~10^(-5))Pa obtained in the test chamber.The experimental results show that the NEG pump is in the best pumping state after activation,and when the pumping speed decreases,it can be placed under ultra-high vacuum conditions for a period of time to restore the pumping speed to the initial state,but the overall pumping performance of the pump changes to a certain extent.When the pump continuously pumps,the pumping speed gradually decreases with the increase of sorbed quantity,and decreases with the increase of test chamber pressure.