Kasthurirangan S, Agnihotri A N, Desai C A, Tribedi L C
Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Colaba, Mumbai 400005, India.
Rev Sci Instrum. 2012 Jul;83(7):073111. doi: 10.1063/1.4738642.
The x-ray bremsstrahlung spectrum emitted by the electron population in a 14.5 GHz ECR plasma source has been measured using a NaI(Tl) detector, and hence the electron temperature of the higher energy electron population in the plasma has been determined. The x-ray spectra for Ne and Ar gases have been systematically studied as a function of inlet gas pressure from 7 × 10(-7) mbar to 7 × 10(-5) mbar and for input microwave power ∼1 W to ∼300 W. At the highest input power and optimum pressure conditions, the end point bremsstrahlung energies are seen to reach ∼700 keV. The estimated electron temperatures (T(e)) were found to be in the range 20 keV-80 keV. The T(e) is found to be peaking at a pressure of 1 × 10(-5) mbar for both gases. The T(e) is seen to increase with increasing input power in the intermediate power region, i.e., between 100 and 200 W, but shows different behaviour for different gases in the low and high power regions. Both gases show very weak dependence of electron temperature on inlet gas pressure, but the trends in each gas are different.
利用碘化钠（铊）探测器测量了14.5吉赫兹电子回旋共振（ECR）等离子体源中电子群体发射的X射线轫致辐射谱，从而确定了等离子体中高能电子群体的电子温度。系统研究了氖气和氩气的X射线谱随入口气体压力从7×10⁻⁷毫巴到7×10⁻⁵毫巴以及输入微波功率从约1瓦到约300瓦的变化情况。在最高输入功率和最佳压力条件下，端点轫致辐射能量达到约700千电子伏特。估计的电子温度（T(e)）在20千电子伏特至80千电子伏特范围内。发现两种气体的T(e)在压力为1×10⁻⁵毫巴时达到峰值。在中等功率区域，即100至200瓦之间，T(e)随输入功率增加而升高，但在低功率和高功率区域，不同气体表现出不同行为。两种气体的电子温度对入口气体压力的依赖性都非常弱，但每种气体的趋势不同。
