High resolution digital holographic interferometry on the Fusion Z-pinch Experiment FuZE

The Fusion Z-Pinch Experiment (FuZE) is a sheared flow stabilized (SFS) Z-pinch experiment investigating the scaling of SFS Z-pinch plasmas towards fusion conditions. Sustained neutron production has been measured from cylindrical plasmas of high density (> 10¹⁷/cm³), high temperature (> 1 keV), and small radii (< 5 mm) [1]. Diagnosing the size, density and internal structure of these plasmas require a high spatial resolution plasma density diagnostic. Motivated by this, a holographic interferometer with 10 micron spatial resolution has been installed on FuZE [2]. A Nd:YAG laser is used with a digital camera to produce holograms from the plasma assembly region. Digital holograms are numerically reconstructed to obtain the chord-integrated electron density of the compressed plasma, with fine spatial resolution. Assuming cylindrical symmetry, radial density profiles are reconstructed from electron density data. Radial temperature profiles are calculated by assuming radial force balance, and uniform plasma drift velocity. Chord-integrated density, radial density and radial temperature data are presented from FuZE.

[1] Y. Zhang et al., PRL, Manuscript submitted for publication.

[2] M.P. Ross & U. Shumlak, RSI 87, 103502 (2016).