HL-2M装置质谱测量的初步结果

Preliminary Results of Mass Spectrometry Measurements for HL-2M Tokamak

利用四极质谱计对HL-2M真空室分别在烘烤和辉光放电清洗过程中的残余气体进行了初步测量分析,并且研究了HL-2M抽气系统中低温泵对水的抽除效果。真空室经过最高100℃烘烤后,M/q=18(H_(2)0)、M/q=28(CO)的气体分压强分别减少47.96%、17.63%;对HL-2M进行辉光放电清洗时M/q=18(H_(2)O)、M/q=28(CO)、M/q=32(O_(2))的离子流显著增加,清洗产物通过抽气系统排除,有效地减少了碳、氧等杂质;在4台低温泵抽气并达到动态平衡时M/q=18(H_(2)O)、M/q=28(CO)分压强分别减少了3.2×10^(-5)Pa、3.7×10^(-6)Pa。质谱测量结果为保障HL-2M装置的初始等离子体放电提供了有用的参考数据。

A quadrupole mass spectrometer was used to measure and analyze the residual gas in the vacuum vessel of HL-2M in the process of baking and glow discharge cleaning(GDC),and the pumping performance of the cryopumps for H2O in the pumping system was studied.After baking with a maximum temperature of 100℃,the partial pressure of 18(H_(2)O)and 28(CO)were reduced by 47.96%and 17.63%,respectively.The ion current of 18(H_(2)O),28(CO)and 32(O_(2))during the GDC went down remarkably.And the product of the GDC was exhausted by the pumping system,which effectively reduced impurities such as carbon and oxygen.The partial pressure of 18(H_(2)O)and 28(CO)were reduced by 3.2×10^(-5)Pa and 3.7×10^(-6)Pa,respectively,with four cryopump operation and the steady state vacuum.Mass spectrometry measurement and analytical results provide useful supports for the initial plasma discharge of the HL-2M tokamak.