Study on an efficient keV X-ray laser from a cluster target pumped by a table-top high-power laser

台式高功率激光器泵浦簇靶高效keV X射线激光器的研究

基本信息

批准号：
08405009
负责人：
KONDO Kiminori
金额：
$ 27.2万
依托单位：
University of Tsukuba
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

项目摘要

In the soft x-ray region, x-ray lasers have been already succeeded in the oscillation. However, in the hard x-ray region (the keV region), it is not. For having an oscillation in the keV X-ray laser. the efficient pumping method has to be developed. Then we studied on the new x-ray laser scheme, in which the population inversion in the keV X-ray region is excited by the multiphoton innershell excitation process. A relativistic and charge-displacement sell-channeling is also studied for making the gain length long with keeping the intense optical field of 10^<18> W/cm^2.For the multiphoton innershell excitation, the wavelength dependence of M- and L-shell emission from Xe cluster target has been studied. KeV X-ray spectra have been measured with using a TW Ti : sapphire laser. By comparing with the results with a KrF laser, the conversion efficiencies from a laser light to X-rays are proved to be small. In M-shell emission, the conversion efficiency in Ti : sapphire was -10^<-2> times smaller than that in KrF, and in L-shell -1O^<-3> times. These results are thought to be very important for the development of the keV X-ray laser.For the study on the relativistic and charge-displacement laser channeling, we measured the time-resolved backlighted image of the propagation of the TW Ti : sappghire laser pulse. In order to drive the self-channeling, the injected laser power must be larger than a critical power which strongly depends on the plasma density. From the results of our measurement, it was proved that, in Xe cluster target, the relativistic and charge displacement self-channeling seemed to happen, when the target gas density becomes high enough.

在软X射线区域，X射线激光器已经成功振荡。然而，在硬X射线区域（keV区域），情况并非如此。用于在 keV X 射线激光器中产生振荡。必须开发有效的泵送方法。然后我们研究了新的X射线激光方案，其中keV X射线区域的粒子数反转是由多光子内壳激发过程激发的。还研究了相对论和电荷位移销售沟道，以在保持 10^<18> W/cm^2 的强光场的情况下延长增益长度。对于多光子内壳激发，M- 和 L 的波长依赖性研究了 Xe 簇靶的壳层发射。 KeV X 射线光谱是使用 TW Ti：蓝宝石激光器测量的。通过与KrF激光器的结果比较，证明从激光到X射线的转换效率很小。在M-壳层发射中，Ti:蓝宝石中的转换效率比KrF中的小-10^<-2>倍，并且在L-壳层中小-10^<-3>倍。这些结果被认为对于keV X射线激光器的发展非常重要。为了研究相对论和电荷位移激光通道，我们测量了TW Ti：蓝宝石激光器传播的时间分辨背光图像脉冲。为了驱动自沟道，注入的激光功率必须大于临界功率，该临界功率很大程度上取决于等离子体密度。我们的测量结果证明，在Xe团簇靶中，当靶气体密度足够高时，似乎会发生相对论和电荷位移自沟道。