论文标题
对激光驱动的高Z箔的X射线排放的详细研究在广泛的强度范围内：转化层和恢复区的作用
Detailed investigation on x-ray emission from laser driven high-Z foils in a wide intensity range : role of conversion layer and reemission zone
论文作者
论文摘要
进行了详细的辐射流体动力模拟，以研究四个高Z平面目标的X射线发射过程，即钨（W），金（AU），铅（Pb）和铀（U），由1 ns，351 nm，351 nm平面平坦的顶部激光脉冲。在$ 10^{12} -10^{15} w/cm^{2} $的广泛强度范围内，对所有激光驱动的高Z箔进行了彻底的分区分析，并具有适当选择的光子能量范围和重组参数。全强度范围内的转化效率的变化对于所有材料都表现出最佳效果，这可以通过考虑来自激光照射的两个不同区域的特征发射贡献，即转化层和缓解区。在软/m波段X射线区域中，提出了一种基于平滑损坏效率定律的新的广义单缩放关系，以用于转换效率变化（$η_{s} $，$η_{m} $），提出了一种转换效率变化（$η_{s} $）。已经观察到，PB的$η_{s} $始终在Au和U之间，对于小于$ \ sim 3 \ sim 3 \ times 10^{13} w/cm^{2} $的强度。在进一步提高强度时，观察到$η_{s} $对于au和u是最小的，而u对于W的最低限度。在所有元素中都观察到对M波段转换效率的重要贡献，对于高于$ \ sim 2 \ sim 2 \ sim 2 \ sim 2^{13} w/cm^{2} w/cm^{2} $的强度，最大值和最大值由最大值和最大值。结果是通过考虑转换层和重新排放带的所有材料的发射系数的贡献来解释结果，直到不同激光强度处的相应光子截止能量。
Detailed radiation hydrodynamic simulations are carried out to investigate x-ray emission process in four high-Z planar targets namely, tungsten (W), gold (Au), lead (Pb) and uranium (U) irradiated by 1 ns, 351 nm flat top laser pulses. A thorough zoning analysis is performed for all laser driven high-Z foils over a wide intensity range of $10^{12}-10^{15} W/cm^{2}$ with appropriately chosen photon energy range and recombination parameter. The resulting variation of conversion efficiency over the full intensity range exhibits an optimum for all materials which is explained by considering the characteristic emission contributions from two different regions of laser irradiated plasma, namely, conversion layer and remission zone. A new generalized single scaling relation based upon smooth broken power law is proposed for conversion efficiency variation along with the separate determination ($η_{S}$, $η_{M}$) in soft and hard/M-band x-ray regions. It has been observed that $η_{S}$ for Pb and W always lies in between that for Au and U for intensities smaller than $\sim 3\times 10^{13} W/cm^{2}$. On further increase in intensity, $η_{S}$ is observed to be maximum for Au and U whereas it is minimum for W. Significant contribution to M-band conversion efficiencies is observed in all elements for intensities higher than $\sim 2\times 10^{13} W/cm^{2}$ with maximum and minimum values attained by W and U, respectively. The results are explained by considering the contributions from the emission coefficients of all materials in both conversion layer and reemission zone up to corresponding photon cut-off energies at different laser intensities.
