A STUDY OF KF3- ATTENUATION IN AN RFQ GAS CELL FOR 41Ca AMS.

Guided by simulations using SIMION 8.1, a series of modifications were made to an experimental version of an Isobar Separator for Anions (ISA). The resulting improved version of the ISA provides a means of re-energizing the ions after they are cooled by gas collisions as they pass through the gas-filled radiofrequency quadrupoles (RFQ), and also provides higher transmission efficiencies. Reinvestigation of the separation of CaF₃^- and KF₃^- with this refined apparatus resulted in a better balance between isobar suppression and analyte transmission. KF₃^- was attenuated at eV energies by 4 orders of magnitude while 40% transmission of CaF₃^- was retained, for a 20keV CaF₃^- beam of ɸ2mm and ±12mr. These results advance the possibility of an efficient small ISA-AMS system for both cosmogenic and medical applications of ⁴¹Ca. [ABSTRACT FROM AUTHOR]