Hubert S, Boubault F
Atomic Energy and Alternative Energies Commission, 15 Avenue des Sablières, 33114 Le Barp, France.
Rev Sci Instrum. 2019 Nov 1;90(11):115110. doi: 10.1063/1.5125746.
Calibration of x-ray cameras integrated within plasma diagnostics for Laser MégaJoule's experiment is of great interest for interpretations of physical phenomena. At the Atomic Energy and Alternative Energy Commission, an x-ray calibration laboratory has been trying for many years to provide the most relevant calibrations. In the soft x-ray range (<1.5 keV), a model 5 Manson source is used in combination with a concave grating monochromator equipped permanently with an absolute calibrated silicon drift detector. To reduce the calibration time achieved with this experimental setup, the Manson source has been modified to reach an emission current of up to 5 mA (100 µA for a standard source model) while keeping the x-ray monochromatic intensity constant within ∼2% for several operating hours. A water cooling system has been integrated within the anode carousel and an emission current regulation system inside a completely redesigned power supply. In this work, we present characterization of the source size and x-ray intensity as a function of both source voltage and emission current, as well as the stability of this new source. Both arms of the source have been used: one for monitoring the monochromatic spectra and x-ray intensity and the other to measure the source size. An x-ray spot was observed to be evolved from the oval shape toward the annular one as the emission current increases. For fixed emission current, the source size is reduced as the voltage increases. The x-ray intensity has significantly been increased to a maximum factor of ∼20 (depending on the anode) while being constant within around 2% as expected.
对激光兆焦耳实验中集成在等离子体诊断设备内的X射线相机进行校准，对于解释物理现象具有重要意义。在原子能与替代能源委员会，一个X射线校准实验室多年来一直致力于提供最相关的校准。在软X射线范围（<1.5 keV）内，使用5型曼森源与永久配备绝对校准硅漂移探测器的凹面光栅单色仪相结合。为了减少这种实验装置的校准时间，对曼森源进行了改进，使其发射电流可达5 mA（标准源模型为100 µA），同时在几个工作小时内将X射线单色强度保持在约2%的恒定范围内。在阳极转盘内集成了一个水冷却系统，并在完全重新设计的电源内部设置了一个发射电流调节系统。在这项工作中，我们展示了源尺寸和X射线强度随源电压和发射电流的变化特性，以及这种新源的稳定性。使用了源的两个臂：一个用于监测单色光谱和X射线强度，另一个用于测量源尺寸。观察到随着发射电流增加，X射线光斑从椭圆形演变为环形。对于固定的发射电流，源尺寸随着电压增加而减小。X射线强度显著增加，最大增加因子约为20（取决于阳极），同时如预期的那样在约2%的范围内保持恒定。
