真空氦检漏技术在ITER项目中的应用

Application of vacuum hot Helium leak testing technology for ITER projec

包层屏蔽块是国际热核聚变实验堆(ITER)项目的重要组成部件。每个屏蔽块都需要进行真空热氦检漏,以确保其密封性能。提出了一种利用真空热氦检漏系统进行高灵敏度检测的方法,该系统可以使包层屏蔽块去除自身的杂质气体来规避干扰,并通过提高环境温度和屏蔽块内部和外部之间压力差的方式来提高氦原子的活性以提高检测灵敏度。该方法可在检测环境温度为250℃,环境压力为1×10^(-5)Pa,产品内部氦气压力为4 MPa的条件下,实现系统灵敏度为10-11Pa·m^(3)·s^(-1)数量级的氦气泄漏检测。试验结果表明,该技术具有高自动化和数据可追溯的优点,可避免产品自身释放的杂质气体带来的影响,对细微泄漏具有较高的检测灵敏度。

The blanket shield blocks is an important part of the International Thermonuclear Experimental Reactor(ITER).In order to ensure its sealing performance,each shield block needs to be taken a vacuum hot Helium leak testing.A method for high-sensitivity examination using a vacuum thermal helium leak test system was proposed in this paper.The shield blocks can remove its own impurity gas to avoid interference and increase the activity of Helium atoms by increasing the environment temperature.The examination sensitivity was improved by increasing the pressure difference between the inside and outside of the shield block.The sensitivity of this method can realize the helium leak test with the system sensitivity of 10-11 Pa·m^(3)·s^(-1)orders of magnitude under the conditions of examination environment temperature of 250℃,ambient pressure of 1×10^(-5)Pa,and products internal helium pressure of 4MPa.The results indicated that the technology hada high degree of automation and data traceability,which can avoid the influence of the product′s own outgassing on the examination,and had high sensitivity to the examination of subtle air leakage.