Beam modelling and hardware design of an imaging heavy ion beam probe for ASDEX Upgrade

Abstract

The imaging heavy ion beam probe (i-HIBP) developed at the ASDEX Upgrade tokamak is a new diagnostic concept for investigations at the edge of high temperature plasmas. By means of a heavy alkali beam injector, a neutral primary beam of an energy of 70 keV is injected into the fusion plasma, where it is ionized generating a fan of secondary beams. These are deflected by the magnetic field of the tokamak and intersect a scintillator plate in the limiter shadow of the tokamak. The light pattern on the scintillator detected with a high speed camera contains radial information on the density, electrostatic potential and the magnetic field in the edge region of the plasma. For the design of the i-HIBP, a detailed beam model including the 3D tokamak magnetic field and beam attenuation effects for cesium and rubidium atoms is developed in order to find the optimum injection scheme within the limited space of the tokamak environment for maximum 1Corresponding author.

Implementation of synthetic fast-ion loss detector and imaging heavy ion beam probe diagnostics in the 3D hybrid kinetic-MHD code MEGA

“…Detector (FILD) and the imaging Heavy-Ion Beam Probe [14][15][16] (i-HIBP). For the former, a realistic 3D wall for the AUG tokamak has been implemented in MEGA showing a correlation between the fast-ion losses toward the wall and the AE activity in the simulations.…”

Characterization of scintillator screens under irradiation of low energy 133Cs ions

“…A new diagnostic, the Imaging Heavy Ion Beam Probe (i-HIBP), has been installed in the ASDEX Upgrade (AUG) tokamak at the Max Planck Institute for Plasma Physics (IPP) [1][2][3]. Unlike standard heavy ion beam probes, in the i-HIBP the probing (heavy) ions are collected by a scintillator detector, creating a light pattern or strike-line, which is then imaged by a camera.…”

“…The plasma density profile can be retrieved from the signal intensity, for which a comprehensive knowledge of the scintillator response is needed. A more detailed description of the measurement principle of the i-HIBP can be found in [1,3]. Ionoluminescence consists in the emission of light by a material when it is irradiated by ions.…”

“…• A high efficiency or yield, i.e. number of emitted photons per irradiated ion (expected current densities at the i-HIBP scintillator plate of mA/m 2 [1]). A high yield means a high i-HIBP signal.…”

Implementation of synthetic fast-ion loss detector and imaging heavy ion beam probe diagnostics in the 3D hybrid kinetic-MHD code MEGA

“…These synthetic diagnostics are based on two of the diagnostic systems in AUG: the poloidal array of Fast-Ion a) Electronic mail: poyola@us.es b) See author list of H. Meyer et al Nucl. Fusion 59, 112014 (2019) Loss Detector (FILD) and the imaging Heavy-Ion Beam Probe [14][15][16] (i-HIBP). For the first, a realistic 3D wall for the AUG tokamak has been implemented in MEGA showing a correlation between the fast-ion losses towards the wall and the AE activity in the simulations.…”