Magnetized gas puff Z-pinch experiments on the CESZAR LTD

Z-pinches are powerful sources of X-rays and neutrons but are prone to developing disruptive magneto-Rayleigh Taylor (MRT)instabilities. One proven [1] mitigation technique is embedding an axial magnetic field into the plasma column prior to implosion. Recent experiments [2] on gas puffs imploded on an 300kA, 1.6ns driver showed that the axial magnetic field stabilized the pinch but also increased implosion time and decreased pinch compression. Here, we present results of gas puff Z-pinches with a pre-embedded axial magnetic field conducted on the CESZAR linear transformer driver (LTD) at UCSD with 500kA current and 150ns rise time. The pinch stability and implosion times were measured for values of initial axial magnetic field, Bz0 = 0-1T using a combination of diagnostics including filtered photodiodes, time-gated XUV pinhole imaging, laser schlieren imaging and interferometry. These results provide insight on the effects of axial magnetic fields on fast (≤ 200 ns) implosions driven by low-impedance current generators.         

1. F. Conti, N. Aybar, J.Narkis, J. C. Valenzuela, H.U. Rahman, E. Ruskov, E. Dutra, S. Haque, A. Covington, and F. N. Beg, “Study of stability in a liner-on-target gas puff z-pinch as a function of pre-embedded axial magnetic field”, Phys. Of Plasmas 27, 090401 (2020).

2. D. Mikitchuk et al., "Mitigation of Instabilities in a Z-Pinch Plasma by a Preembedded Axial Magnetic Field," in IEEE Transactions on Plasma Science, vol. 42, no. 10, pp. 2524-2525, Oct. 2014, doi: 10.1109/TPS.2014.2327094.