How Simply One Can Considerably Improve Performance of the Gas Stripper at the GSI UNILAC (Proposal)

In this paper, we propose a simple way in which one can considerably improve performance of the gas stripper setup at the GSI UNILAC. To do so, it will be enough just to use the classic and well known design concept for internal gas jet targets, by installing the gas catcher tube at some distance from the supersonic nozzle exit. As a result, the background pressure in the main and differentially pumped adjacent vacuum chambers of the gas stripper at the GSI UNILAC will dramatically reduce, and it will make it possible to achieve the required optimal target thicknesses in the mode of continuous gas jet operation. In addition, the pulsed stripper operation mode is simply realized by implementing a commercially available fast gas valve connected to the nozzle inlet. In this case, there is a possibility to achieve better stripping efficiency and higher average charge states of uranium ion beam after passing through the hydrogen pulsed jet target. More-over, the ion beam pulses repetition rate can be increased, and it will allow the higher average intensity of the ion beams extracted from the GSI UNILAC. The functionality of the proposed GSI UNILAC gas stripper modification and the design of its key components we explored by detailed gas dynamic simulations, which results are presented and discussed.