Estimation of plasma parameters of X-pinch with time-resolved x-ray spectroscopy  

作　　者：Seunggi Ham Jonghyeon Ryu Hakmin Lee Sungbin Park Y.-C.Ghim Y.S.Hwang Kyoung-Jae Chung 

机构地区：[1]Department of Energy Systems Engineering,Seoul National University,Seoul 08826,South Korea [2]Department of Nuclear and Quantum Engineering,KAIST,Daejeon 34141,South Korea

出　　处：《Matter and Radiation at Extremes》2023年第3期34-46,共13页极端条件下的物质与辐射（英文）

基　　金：This research was supported by the Defense Research Laboratory Program of the Defense Acquisition Program Administration and Agency for Defense Development of the Republic of Korea.

摘　　要：We estimate the parameters of a Cu plasma generated by an X-pinch by comparing experimentally measured x-rays with synthetic data.A filtered absolute extreme ultraviolet diode array is used to measure time-resolved x-ray spectra with a spectral resolution of∼1 keV in the energy range of 1–10 keV.The synthetic spectra of Cu plasmas with different electron temperatures,electron densities,and fast electron fractions are calculated using the FLYCHK code.For quantitative comparison with the measured spectrum,two x-ray power ratios with three different spectral ranges are calculated.We observe three x-ray bursts in X-pinch experiments with two Cu wires conducted on the SNU X-pinch at a current rise rate of∼0.2 kA/ns.Analysis of the spectra reveals that the first burst comprises x-rays emitted by hot spots and electron beams,with characteristics similar to those observed in other X-pinches.The second and third bursts are both generated by longlived electron beams formed after the neck structure has been completely depleted.In the second burst,the formation of the electron beam is accompanied by an increase in the electron density of the background plasma.Therefore,the long-lived electron beams generate the additional strong x-ray bursts while maintaining a plasma channel in the central region of the X-pinch.Moreover,they emit many hard x-rays(HXRs),enabling the SNU X-pinch to be used as an HXR source.This study confirms that the generation of long-lived electron beams is crucial to the dynamics of X-pinches and the generation of strong HXRs.

关 键 词：RESOLVED PARAMETERS ABSOLUTE 

分 类 号：TL5[核科学技术—核技术及应用]