Proposal for applying the novel gas-dynamic ion-beam extraction and bunching technique to the cryogenic stopping cells at FAIR

Abstract

To enhance the quality of pulsed cold ion beams extracted from the two cryogenic stopping cells at FAIR (i.e., the one currently used in the FRS and the one under development for the Super-FRS at FAIR), we propose using a novel gas-dynamic ion beam extraction and bunching technique as an alternative to the radiofrequency quadrupole (RFQ) method. This technique allows for 100% ion transmission by placing a short stack of thin cylindrical electrodes behind the extraction RF carpet. Detailed gas-dynamic and ion trajectory computer simulations demonstrate that implementing this proposal will enable the achievement of world-record emittance values for ion beams in a wide mass range. The results of these simulations are presented and discussed.