An Ion Guide for the Production of a Low Energy Ion Beam of Daughter Products of $\hat{I}\pm$-Emitters

Abstract

A new ion guide has been modeled and tested for the production of a low energy ($\approx$ 40 kV) ion beam of daughter products of alpha-emitting isotopes. The guide is designed to evacuate daughter recoils originating from the $\hat{I}\pm$-decay of a ${}^{233}$U source. The source is electroplated onto stainless steel strips and mounted along the inner walls of an ion guide chamber. A combination of electric fields and helium gas flow transport the ions through an exit hole for injection into a mass separator. Ion guide efficiencies for the extraction of ${}^{229}$Th${}^{+}$ (0.06%), ${}^{221}$Fr${}^{+}$ (6%), and ${}^{217}$At${}^{+}$ (6%) beams have been measured. A detailed study of the electric field and gas flow influence on the ion guide efficiency is described for two differing electric field configurations.

13 pages, 11 figures, 4 tables. Submitted to Nucl. Instr. Meth. B