The high-density Z-pinch as a pulsed fusion neutron source for fusion nuclear technology and materials testing

Abstract

The dense Z-pinch (DZPl is one of the earliest and simplest plasma heating and confinement schemes, Recent experiment al advances based on plasma initiation from hair-like (10s pm in radius) solid hydrogen fiiaments have so far not encountered tlie usually devastating MHD instabilities that plagued early DZP experimenters. These encouraging results alorg with debut of a number of proof-of principle, high-current (1-2 MA in 10-100 ns) experiments have prompted consideration of the DZP as a pulsed source of DT fusion neutrons of sufficient strength (SN~1019 n/s) to provide uncollided neutron fluxes in excess of lW = 5-10 MW'/7n2 over test volumes of 10-30 !it re or greater. W1.ile this neutron source would be pulsed (100s 12s pulse widths, 10-100 Hz pulse rate), giving flux time compressions in the range 105-106, its simphcit.y, near-term feasibility, low cost, high-Q operation, and relevance to fusion systems that may provide a ptdsed commercial end-product (e.g., inertial confinement or the DZP itself) together create the impetus for preliminary consideration as a Iieut.ron source for fusion nuclear technology and materials testings, The results of a preliminary parametric systems study (focusing primarily on physics issues), conceptual design, and cost versus performance analyses are presented. The DZP promises an inexpensive and efficient, means to provide pulsed DT neutrons at an average rate in excess of 1019 n/s, with neutron currents Iu, X: 10 M W/m2 over volumes v esp 2 30 lit.re using single-pulse teclmologim that differ little from those being Ilsed in present-day experilllelltf. 1. INTRODUCTION [rapwtl-zpinch-6 /7/09-1 magnetohydrodynamic (MHD) deformations. Linear, ideal (zero resistivit.y) MHD theory predicts3-s reduced growth rates, or even stability for the m = O mode, if the current profiles are sufficiently diffuse. Minimum pressure profiles for which the m = O nlode is 4'5 The stabilizing effects of external gss ideally and linearly stable have been reported, pressure4 or finite ion Larmor radiuse have also been suggested, The development of improved high-voltage, pulsed-diagnostic, and pi:lcll-forlllatioll techniques together have led to improved results for the DZP7 and an emanced appreciation for the impact of formation conditions and plasma profiles on the pinch behavior. Recent DZP experiments at Los Alan~os8~g and at the Naval Research Laboratory 10 have initiated high-voltage discharges through small-radius (10-40 pm), solid-deuterium fibers. These I = 0.3-0.6 MA experiments do not observe the m = 1 kink instability, and the m = O sausage instability y is suppressed for 100s of Alfv6n transit times across the pinch radius as long as the plasma current is increasing (~> O). While transport and stability analysesl 1'12 are being conducted using three-dimensional resistive models in both linear aud non-linear regimes, the stability of these fiber initiated DZPS remains enigmatic, indicating the in~portance of formation method, pinch profiles, local (edge-plasma) dissipation, and dynamic stabi...

Production and applications of neutrons using particle accelerators

“…Dense plasma focus neutron sources are pulsed-power instruments that discharge intense electrical currents to produce plasma. [122][123][124][125][126][127][128][129] Deuterium is the most commonly used gas in these systems, with neutron generation originating from deuterium fusion within the plasma. The electrical discharge and plasma formation in these devices is a highly energetic process and historically has resulted in substantial damage to the plasma generating electrodes.…”

High yield (⩾108/pulse) DD neutron generator based on a compact, transportable and low energy plasma focus device

“…Over the years, various kinds of pulsed neutron sources have been developed based on different methods e.g. the particle accelerator [4], the pulsed laser plasma accelerator [3,5], spallation [6], the inertial confinement scheme [7], the z-pinch [8][9][10][11][12] and the plasma focus (PF) device [13,14]. The PF device is a widely known pulsed intense source of neutrons [only when filled with deuterium (D 2 ) or deuterium-tritium (D-T) mixture gas], x-rays, electrons and ions, among other radiations.…”