Scintillation light produced by low-energy beams of highly-charged ions

TL;DR

This study measures how low-energy, highly-charged ion beams produce scintillation light in inorganic scintillators, revealing a linear relationship with kinetic energy and minimal influence from potential energy, with implications for beam diagnostics.

Contribution

It provides the first detailed measurements of scintillation light produced by low-energy, highly-charged ions, highlighting the linear energy dependence and potential for beam diagnostics.

Findings

Scintillation intensity depends linearly on kinetic energy deposited.

No significant contribution from ions' potential energy up to charge state 18.

Potential application in beam diagnostics at facilities like GSI.

Abstract

Measurements have been performed of scintillation light intensities emitted from various inorganic scintillators irradiated with low-energy beams of highly-charged ions from an electron beam ion source (EBIS) and an electron cyclotron resonance ion source (ECRIS). Beams of xenon ions Xe$^{q+}$ with various charge states between $q$=2 and $q$=18 have been used at energies between 5 keV and 17.5 keV per charge generated by the ECRIS. The intensity of the beam was typically varied between 1 and 100 nA. Beams of highly charged residual gas ions have been produced by the EBIS at 4.5 keV per charge and with low intensities down to 100 pA. The scintillator materials used are flat screens of P46 YAG and P43 phosphor. In all cases, scintillation light emitted from the screen surface was detected by a CCD camera. The scintillation light intensity has been found to depend linearly on the kinetic ion energy per time deposited into the scintillator, while up to $q$=18 no significant contribution from the ions' potential energy was found. We discuss the results on the background of a possible use as beam diagnostics e.g. for the new HITRAP facility at GSI, Germany.