DEVELOPMENT OF SOFT X-RAY INTERFEROMETRY WITH SYNTHETIC MULTILAYERS AND APPLICATION TO WAVEFRONT MEASUREMENTS AND CONTROL OF PRECISION IMAGING MIRRORS

本研究的目的是利用我们的软x射线多层材料制造技术，开发波长为13nm的正入射光学精密成像镜。研究了高精度波前测量和校正方法，开发了高质量成像所需的高精度1 nm以上的软x射线干涉测量法。在开发过程中，除了能够实现nm精度测量的干涉仪光学对准系统外，还开发了通用成像系统的基本组成。其中包括yag激光产生的无碎片污染的等离子体的软x射线光源，以及用于软x射线干涉图检测的具有数据处理和分析系统的二维探测器。在本财政年度，持续的努力导致了基本组成部分的成功开发，即光源、干涉光学和探测器。在光源组件方面，已经开发出一种明亮的光源，可以用YAG激光脉冲一次记录软x射线干涉图。在该组件中，将直径为10cm的多层聚光镜设置为0.2 NA配置，有效地收集位于距镜子21cm的固体Sn目标的软x射线。设计和制造的机械碎片塞可以清除目标的碎片。有了碎片塞，源的寿命延长到40000次10倍，去除的碎片颗粒占总碎片质量的90%。在光学方面，精密成像镜衬底上多层周期分布的精度从去年的2%提高到1%以内。为了实现这种控制，我们构建了一个新的机械快门系统，该系统具有控制开合运动速度的功能。在探测器方面，利用我们的光谱反射计研究了Tr成像板对软x射线的灵敏度和检测线性度。在约13 nm波长处，证实了100000光子/ mm^2的高灵敏度和超过4个数量级的良好线性。少

This research aims development of precision imaging mirrors for normal incidence optics at a wavelength of 13 nm with our fabrication expertise of soft X-ray multilayers. Methodology of precise wavefront measurement and correction has been investigated with development of soft X-ray interferometry of high accuracy better than 1 nm, needed for high quality imaging. In the development process, in addition to the interferometer optics with alignment system enabling nm accuracy measurement, basic compositions for general imaging systems are developed. These include a soft X-ray light source of a YAG-laser produced plasma free from debris contamination to optics, as well as a 2-dimensional detector with a data handling and analysis system for soft X-ray interferogram detection.In this fiscal year, continuing effort leads to successful development of the basic compositions, i.e., the light source, interferometry optics, and the detector.As for the light source assembly, a bright source has b … More een developed enabling soft X-ray interferogram recording by one shot of the YAG laser pulse. In this assembly, a multilayer condenser mirror of 10 cm in diameter is set at 0.2 NA configuration, effectively collecting soft X-ray of a solid Sn target locating 21 cm away from the mirror. A mechanical debris stopper designed and constructed removes the debris of the target. With the debris stopper, the life of the source are elongated to 40000 shots by 10 times with removal of debris particles forming 90 % of total debris mass.As for the optics, accuracy of the multilayer period distribution over the substrate of the precision imaging mirror has been improved from last year's 2 % to within 1 %. For this control, a new mechanical shutter system has been constructed with a function controlling speed of the open and close movements.As for the detector, imaging plates for Tr were investigated in respect to the sensitivity and detection linearity for the soft X-ray with use of our spectro-reflectometer. At around 13 nm wavelengths, high sensitivity of 100000 photons / mm^2 and good linearity over 4 orders of magnitudes were confirmed. Less