X-Ray Filter with Variable Transmission for Experiments on the Action of a Multi-Terawatt Pulse of Soft X-Ray Radiation on Targets.

The results of experiments on the effect of soft X-ray radiation (SXR) on thin mylar films of micron thickness are presented. The main result of the research is the development and testing of an adaptive filter—a filter made of mylar (hereinafter, My) film with time-varying transparency. This film is necessary for profiling the multi-terawatt soft X-ray radiation pulse in the experiments on radiation ablation of the targets made of layers of some metals (e.g., Al, Ni, In, Sn, Au, Bi, etc.), currently being carried out at the Angara-5-1 facility. Such a film absorbs almost all the energy of the preliminary pulse (the so-called "pre-pulse") and becomes "transparent" by the time the main terawatt radiation pulse occurs. The distance between this film and the target under study is chosen so as not to damage the target by the spreading filter substance during its radiation heating. Thus, the target layer initial density at the time of its irradiation by the main SXR radiation pulse will increase significantly. The use of an adaptive filter makes it possible to determine the change in the target layer transparency in a wider range of the initial values of its density and to reduce the influence of the target expansion dynamics on the accuracy of measuring its spectral transparency. [ABSTRACT FROM AUTHOR]