Experimental characterization of high current X-pinch plasma source and study of the influence of an energetic electron beam on the source parameters.

摘要

The importance of this work is its connection with the extensively developing ICF program and the opportunity for practical application of z-pinch plasma x-ray sources. The unique properties of z-pinch pulse powered plasma sources allow the creation of plasma with thermonuclear parameters and the study of the physics of the processes in the matter with extreme density and temperature.; This dissertation presents the results of five years work on diagnostics design and experimental studies of X-pinch x-ray sources produced mainly by 0.9--1 MA and partly by 0.3--0.4 MA currents. A diagnostics complex used in presented experiments covered a spectral range from 10 up to 106 eV with spatial, spectral, and time resolution. The main results of this work are detailed characterization of a high current (0.9--1.0 MA) X-pinch plasma source and an understanding of the influence of X-pinch energetic electron beams on plasma properties. The time and energy scaling measurements for the ∼1 MA current machine were carried out for radiation from K- and L-shells of Ti and Fe, K-, L-, and M-shells of Mo, and M-shell of W. A comparison of 2--10 keV yields with the total electron beam energy scaling suggests two competing mechanisms of energy dissipation---one through generation of the electron beam, another through x-ray thermal plasma radiation. In addition to the time and energy scaling, extensive investigations of X-pinch x-ray sources in the 0.15--100 keV spectral range, plasma jets, and electron beams, and time-gated spectroscopy of X-pinches were carried out.; The present work shows that an X-pinch can be proposed as a hard x-ray (>40--100 keV) backlighter to study processes with a microsecond time resolution and as a powerful sub-keV radiation driver. High plasma density and temperature observed in the X-pinch experiments allows a possibility of plasma parameters scaling for the experiments on large z-pinch machines with loads driven by a current of ∼10--20 MA.