摘要
石墨的化学腐蚀实验是在ＬＡＳ－２０００二次离子质谱仪的分析室中进行的，用高能氘离子束或与电子束联合辐照石墨，石墨温度从３００—１０００Ｋ可调。辐照下释放的产物用四极质谱探头进行了质谱分析，得到了１．３μＡ、３ｋｅＶ氘束轰击下ＳＭＦ－８００石墨释放氘甲烷（ＣＤ４）的温度特性，在７８０Ｋ处有一个释放高峰。通过分析指出，氘甲烷产额γ除与居留在石墨表面层的氘原子密度ｎＤ有关外，还应和氘甲基（ＣＤ３）的表面层密度ｎＣＤ３相关，即γ＝ＡｎＤｎＣＤ３ｅｘｐ（－ＥＲ／ＲＴ）。实验拟合出石墨表面层中氘甲烷的化学合成激活能ＥＲ＝７．８ｋｃａｌｍｏｌ－１，ＣＤ３和Ｄ的综合脱附激活能Ｅ１＝３５．８ｋｃａｌ·ｍｏｌ－１。从而进一步阐明：在温度高于８００Ｋ后。
The chemical sputtering of graphite was carried out in an ultrahigh vacuum chamber of secondary ion mass spectrometer. An incident energetic deuterium ion beam was used singly or in combination with an electron beam, to simulate plasma irradiation. The temperature of the graphite sample was regulated from room temperature to 1000K. The sputtering products with m/e from 2 to 44 as a released molecule beam from the irradiated graphite sample have been analysed in situ with a quadruple mass spectrometer SQ156. The temperature characteristic of releasing the deutero methane CD 4 from graphite SMF 800 sample bombarded with a deuterium ion beam of 1.3μA/3keV has been obtained. The releasing peak of CD 4 due to enhanced chemical sputtering is at about 780K. A formula for the CD 4 releasing rate is proposed as γ=An D n CD 3 exp ( E R /RT) . The activation energies E R of 5.2 kcal/mol for CD 4 formation and E 1 of 35.8 kcal/mol for the synthetic thermal desorption of deuterium atom D and deutero methyle CD 3 from the surface region of the graphite were fitted out experimentally.
出处
《核聚变与等离子体物理》
EI
CAS
CSCD
北大核心
1997年第1期43-49,共7页
Nuclear Fusion and Plasma Physics
基金
核工业科学基金
Y932301支持项目
关键词
氘束
石墨
化学腐蚀
温
度特性
反应堆材料
Deuterium beam Graphite Chemical sputtering Temperature characteristic
