【摘要】 针对星光Ⅱ装置的实际条件,提出了以金箔背侧X光辐射作为样品加热源兼作背光源的特色自背光法,研究了辐射不透明度(自由程)实验方法。以波长为0.35μm,能量约80J,脉宽约700ps的强激光注入特色自背光靶,用空间分辨透射光栅配X光CCD由同一发打靶测得了半样品靶的源区、透射区和自发射区三区能谱分布图象,又由不同发次打靶分别测得了源谱、透射谱。样品材料为厚度0.5 μm和1 μm,密度为2.7g/cm~3的铝膜,以及密度为0.042g/cm~3,厚度为42μm的碳氢发泡材料。实验由不同打靶发次测得的源谱和透射谱,初步获得了样品的谱分辨质量吸收系数,进而用空间分辨透射光栅谱仪、由同一发打靶获得了样品考虑自发射的谱分辨质量吸收系数。对样品温度、密度条件进行了相应的实验与理论研究。初步讨论了热碳元素辐射不透明度(Opacity)。更多还原

【Abstract】 Self-backlighting method for opacity measurement has been suggested and studied, based on the actual condition of Xingguang II laser facility. An 80 J and 350 run laser, which has a duration of about 700 ps, irradiates on a newly designed target and creates intense X-ray radiation acting as both heating source and backlighter source. The heated sample has been spatially imaged to obtain X-ray spectra from X-ray source region, transmission region and self-emission region of the sample at the same shot by spatially resolved transmission grating spectrometer in which dispersed X-ray is recorded by X-ray CCD. The samples are low-Z CH foam with density of 0.042 g/cm3, thickness of 42 um and mid-Z Al with density of 2.7 g/cm3, thickness of 0.5 um or 1.0 um. Mass absorption coefficients of the heated sample as function of the photon energy have been obtained experimentally in the same shot. The spectra line emitted from the heated CH foam has also been measured by OHM crystal spectrometer, which has been used to determine the temperature of the sample. The experimental results for opacity of carbon have been discussed.更多还原