Development of Ion Deflectometry for Self-driven B-field Measurements in Z-pinch Plasmas

Ion deflectometry (also ion radiography or ion imaging) is a diagnostic method for measuring EM fields in high-energy-density plasmas [1]. It is based on the displacement measurements of diagnostic ion beams deflected in the EM fields of interest. This method is commonly used in laser-driven plasmas but has not been fully developed in z-pinches. In recent years, we have focused on implementing ion deflectometry for B-field measurements on pulsed power devices [2]. We aimed to extend the use of the ion deflectometry to z-pinch B-fields, which typically have larger spatial scales and can produce stronger ion deflections than the laser-driven B-fields. Since the conventional laser-driven ion backlighting sources are not available in most pulsed power facilities, we investigated the z-pinch-driven sources of accelerated deuteron and fusion-driven proton MeV ion beams [3] and used them to perform the first-ever self-driven deflectometry measurements of currents and azimuthal B-fields in z-pinch plasmas [4,5].

[1] Schaeffer, Derek B., et al. "Proton imaging of high-energy-density laboratory plasmas." Reviews of Modern Physics 95.4 (2023): 045007.

[2] Munzar, V., et al. "Investigation of magnetic fields in Z-pinches via multi-MeV proton deflectometry." IEEE Transactions on Plasma Science 46.11 (2018): 3891-3900.

[3] Klir, D., et al. "Spatial distribution of ion emission in gas-puff z-pinches and dense plasma foci." Plasma Physics and Controlled Fusion 62.3 (2020): 035009.

[4] Munzar, V., et al. "Mapping of azimuthal B-fields in Z-pinch plasmas using Z-pinch-driven ion deflectometry." Physics of Plasmas 28.6 (2021).

[5] Munzar, V., et al. "Self-driven ion deflectometry measurements using 3 MeV hydrogen ions in the hybrid x-pinch on the MAIZE LTD generator." Plasma Physics and Controlled Fusion (submitted in March 2024)