Dynamics of hybrid X-pinches
- PDF / 4,302,264 Bytes
- 19 Pages / 612 x 792 pts (letter) Page_size
- 15 Downloads / 197 Views
MA DYNAMICS
Dynamics of Hybrid Xpinches T. A. Shelkovenkoa, I. N. Tilikina, G. V. Ivanenkova, W. Stepniewskib, A. R. Mingaleeva, V. M. Romanovaa, A. V. Agafonova, A. D. Cahillc, C. L. Hoytc, P. A. Gourdainc, D. A. Hammerc, and S. A. Pikuza a
Lebedev Physical Institute, Russian Academy of Sciences, Leninskii pr. 53, Moscow, 119991 Russia b Institute of Plasma Physics and Laser Microfusion, Hery str. 23, Warsaw, 01497 Poland c Cornell University, Ithaca, New York, 14853 United States email: [email protected] Received May 22, 2014
Abstract—The dynamics of a new type of pinches—hybrid Xpinches (HXPs)—has been studied experi mentally and numerically. The initial configuration of an HXP consists of a highcurrent diode with conical tungsten electrodes separated by a 1 to 3mmlong gap and shunted with a 20 to 100μm diameter wire. It was shown earlier that a hot spot (HS) with high plasma parameters also formed in the HXP, although its ini tial configuration is simpler than that of a standard Xpinch. Although details of the HXP dynamics still remain insufficiently studied, the main factors governing the HXP formation were investigated both experi mentally and using magnetohydrodynamic simulations. The formation of a specific pressure profile in the electrode plasma after the wire explosion was investigated both experimentally and theoretically. It is shown that the effect of the pressure profile on the expanding wire plasma is similar for both standard Xpinches and HXPs, which allows one to assign them to the same class of loads of pulsed facilities. It is also established that the final stages of HS formation and the parameters of the HS plasma in standard Xpinches and HXPs are practically identical. DOI: 10.1134/S1063780X15010031
1. INTRODUCTION
facturing, which, in turn, extends possible applica tions of Xpinches as sources of SXR emission [3–6]. On the basis of HS emission of HXPs, new methods of diagnostics of shortliving plasma objects, such as Xray absorption spectroscopy [3, 4] and Xray Thom son scattering [5], are being currently developed (pre viously, such diagnostics could be implemented only on the basis of laserproduced plasmas).
Hybrid Xpinches (HXPs) with an initial configu ration in the form of a highcurrent diode with conical tungsten electrodes separated by a 1 to 3mmlong gap and shunted with a 20 to 100µmdiameter wire are widely used as point sources of soft Xray (SXR) emission in projection radiography and other applica tions [1–5]. Figure 1a shows the HXP design, and Fig. 1b shows how the HXP used as a source of probing radiation is arranged inside a highcurrent diode. It should be noted that, in this design, the straight through axial channels made in the conical electrodes play an important role in the HXP formation (see Sec tion 4). Our experiments were aimed at studying the features of HXP operation and the parameters of HXP hot spots (HSs) as sources of SXR emission for projec tion radiography and other applications. The experi ments were carried out on four
Data Loading...
