The role of Rayleigh-Taylor instability in the energy deposition to Z-pinch plasma

A mechanism of the Z-pinch plasma heating due to the generation of the magnetic bubbles in the Z-pinch plasma was experimentally investigated. The experiments with single and double shell gas puffs (D60/30 mm) were performed on the IMRI-4 facility (Imax = 350 kA, T/4 = 1.1 mcs). Neon, argon and krypton were used. The plasma was studied with the help of the laser polarointerferometry. The YAG:Nd3+ laser with 532-nm-wavelength was used. The pulse energy was 30 mJ, and FWHM of the laser pulse was 5 ns. The interferometry results show that on the stagnation stage there are some regions inside the plasma column where the radial distribution of electron density have local minimum. The polarimetry results show that inside of these regions there is azimuth magnetic field, that can be interpreted as a magnetic bubble. The measured average magnetic field inside the bubbles is about 600-800 kG, and that is of the order of magnitude of the magnetic field near the plasma boundary. The results of the electrophysical measurements show that the final plasma resistance is about 0.04-0.07 Ohm/cm and depends on the linear gas puff mass. These values of the plasma resistance are of the same order as that predicted by the theory of the enhanced energy deposition into the plasma due to the magnetic bubbles.