Planar Wire-ArrayZ-Pinch Implosion Dynamics and X-Ray Scaling at Multiple-MA Drive Currents for a Compact Multisource Hohlraum Configuration

Abstract

An indirect drive configuration is proposed wherein multiple compact Z-pinch x-ray sources surround a secondary hohlraum. Planar compact wire arrays allow reduced primary hohlraum surface area compared to cylindrical loads. Implosions of planar arrays are studied at up to 15 TW x-ray power on Saturn with radiated yields exceeding the calculated kinetic energy, suggesting other heating paths. X-ray power and yield scaling studied from 1-6 MA motivates viewfactor modeling of four 6-MA planar arrays producing 90 eV radiation temperature in a secondary hohlraum.

New compact hohlraum configuration research at the 1.7 MA Z-pinch generator

“…However, pulsed power offers much more efficient energy coupling than lasers. Here, we report on the first proof-of-the principal experimental demonstration of the full configuration of new compact hohlraum design with a central target and tailored shine shields at UNR's 1.7 MA Zebra generator, as jointly proposed by the Sandia National Laboratories and the University of Nevada, Reno [1]. This was the joint success of two independent lines of multi-year research efforts.…”

Wire ablation dynamics model and its application to imploding wire arrays of different geometries

“…Despite these remarkable achievements the search for new, more effective wire array load configurations continues [5]. This search has inspired several extensive programs for studying the wire array implosion at 1 MA currents at the university based laboratories, first at the Imperial College in UK [6,7] and later at the University of Nevada, Reno (UNR) [8][9][10][11] and Cornell University (see, for example, Ref.…”

“…Since that time numerous experiments have demonstrated that among all the other low-wirenumber loads the planar wire arrays yield the highest x-ray radiation energies and powers [9][10][11]. Two years later, the single planar array loads have been successfully tested at 3 − 5 MA currents on Saturn generator at SNL [5,13,14]. By now, several novel applications of planar wire arrays have been proposed and tested at UNR, such as the new hohlraum design for ICF-related experiments [5], the possibility of controlling the shape of the x-ray radiation pulse [15], the experiments with multi-planar arrays related to the laboratory astrophysics [16], and skewed wire double planar array configurations with induced axial magnetic field [17].…”

“…Two years later, the single planar array loads have been successfully tested at 3 − 5 MA currents on Saturn generator at SNL [5,13,14]. By now, several novel applications of planar wire arrays have been proposed and tested at UNR, such as the new hohlraum design for ICF-related experiments [5], the possibility of controlling the shape of the x-ray radiation pulse [15], the experiments with multi-planar arrays related to the laboratory astrophysics [16], and skewed wire double planar array configurations with induced axial magnetic field [17]. A continuous success in these research directions can be assured by the development and application of reliable modeling tools.…”

“…[22] resulted in the development of an efficient alternative simulation tool for wire array loads of arbitrary geometry, the Wire Dynamics Model (WDM) [18,19] that takes less than one minute simulation time on average personal computer. The WDM has been successfully applied to model the nested cylindrical [12] and single-and multi-planar [19] wire arrays in the current range from 1 MA university level generators to 3−5 MA current levels at SNL [5,13,14]. Nevertheless, despite an obvi-ous efficiency of the WDM, its dynamic picture of imploding wire arrays is quite limited mainly because the momentum redistribution to the plasma ablated from the array wires is disregarded, which among other issues leads to an inaccurate prediction of the implosion time for some heavy wire array loads [12].…”