Speaker
Description
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/O5.304.pdf
Z-pinch dynamic hohlraum (ZPDH) is one of the promising approaches to generate high energy density X-ray to be applicated in inertial confinement fusion, radiation physics and opacity measurements. The quality of the hohlraum radiation field can be characterized by radiation temperature. Brightness temperature provides an integration of the radiation power spectrum over a whole photon energy range, while color temperature is a characteristic quantity of the spectrum shape, which can give the spectrum intensities at different photon energies, providing more insights about the blackbody radiation filed. A suit of multi-channel spectrometer is prepared to be mounted on the Julong-1 facility in China with a peak current of about 8 MA and a rise time of about 70 ns. Multilayer mirrors are used as dispersion elements at different energy bands and photodiodes or photomultipliers are used as detectors in the spectrometer. It will be used to measure the color temperature of the ZPDH using the two-color method. In this method, the ratio of the fluxes of the power spectrum integrated in two different energy bands is used to infer the temperature, as shown in Fig. 1. The energy bands selection is one of the most important questions during the spectrometer design, as the flux ratio may be sensitive to different radiation temperature ranges which are actually unknown. To overcome this difficulty, four energy bands are selected to form six kinds of combinations with each one fit for a temperature range, finally realizing a full cover of the possible temperature scope. Every combination is firstly selected by the maximum flux ratio sensitivity as shown in Fig. 2, which is defined as the derivative of the flux ratio to temperature. In addition, dynamic range, effect of energy band width and uncertainty of this method are also investigated, with which the final optimized energy band combinations are determined.
