Imaging Heavy Ion Beam Probe (iHIBP)

The imaging heavy ion beam probe (i-HIBP) is a novel diagnostic for the measurement of plasma potential, edge current density and magnetic field, and plasma density at the edge of tokamak plasmas. The diagnostic combines the measurement techniques of standard heavy ion beam probes and scintillator based fast-ion loss detectors. By means of a heavy alkali beam injector, a neutral energetic primary beam is injected into the fusion plasma. Electron impact ionizations and charge exchange reactions lead to the formation of a fan of secondary single-charged beams, which is deflected by the tokamak magnetic and electric fields, and detected by a scintillator plate located in the first wall. The strike points on the scintillator generate a characteristic strike-line pattern, which is imaged by means of a fast camera. Information about the plasma potential and the magnetic field can be retrieved from the displacements of the strike-line, while information about the density profile and density fluctuations can be inferred from the light intensity.

Fig. 1.

For more details about the i-HIBP diagnostic at ASDEX Upgrade see:
[1] J.Galdon-Quiroga et al., Conceptual design of a scintillator based Imaging Heavy Ion Beam Probe for the ASDEX Upgrade tokamak, JINST 12, C08023 (2017).
[2] G.Birkenmeier et al., Beam modelling and hardware design of an imaging heavy ion beam probe for ASDEX Upgrade, JINST 14, C10030 (2019).
[3] J.Galdon-Quiroga et al., An imaging heavy ion beam probe diagnostic for the ASDEX Upgrade tokamak, 46th EPS Conference on Plasma Physics (2019).