Generation of Turbulence in Conical Wire Array Plasma Jets and its Effect in the Thomson Scattering Diagnostic.

In the present day, it is believed that turbulence present in a variety of plasma experiments could be affecting a wide range of diagnostics, and thus, interfering in the process of obtaining key plasma parameters. Specifically, with the case of the Thomson Scattering (TS) diagnostic and the widening of the resulting ion feature spectra, it is believed that the ion temperature of the plasma could be getting overestimatded given this "artificial" widening [1]. Therefore, we have designed and implemented an experimental platform for the research and study of hydrodynamic plasma turbulence focused on these key diagnostics, by externally inducing turbulence in collimated supersonic plasma jets given a plastic mesh with a 374 um grid opening [2, 3]. Additionally, we've implemented an imaging refractometer [4] for the purpose of detecting minimal electronic density gradients in the plasma. As a result, we've managed to find the expected widening of the TS spectra at the height of interest, with a significant increase in the ion temperature given the same pulsed-power conditions.

[1] S. V. R. Rocco et al., IEEE Trans. Plasma Sci., vol. 46, no. 11, pp. 3906–3911, 2018.

[2] G. Comte-Bellot and S. Corrsin, J. Fluid Mech., vol. 25, no. 4, pp. 657–682, 1966.

[3] J. Meinecke et al., Nat. Phys., vol. 10, no. 7, pp. 520–524, 2014.

[4] J. D. Hare et al., Rev. Sci. Instrum., vol. 92, no. 3, Art. no. 033521, 2021.