A sextupole ion beam guide to improve the efficiency and beam quality at IGISOL

TL;DR

This paper presents the development and testing of an rf sextupole ion beam guide (SPIG) at IGISOL, demonstrating significant improvements in ion yield and efficiency over the traditional skimmer system through experimental and simulation studies.

Contribution

The paper introduces a novel rf sextupole ion beam guide (SPIG) that enhances ion yield and transmission efficiency at IGISOL, validated by experiments and simulations.

Findings

SPIG improves ion yields by a factor of 4 to 8.

Transport capacity of SPIG is 10^12 ions/sec before space charge effects.

Experimental results agree with simulations as a function of ion current.

Abstract

The laser ion source project at the IGISOL facility, Jyvaskyla, has motivated the development and construction of an rf sextupole ion beam guide (SPIG) to replace the original skimmer electrode. The SPIG has been tested both off-line and on-line in proton-induced fission, light-ion and heavy-ion induced fusion-evaporation reactions and, in each case, has been directly compared to the skimmer system. For both fission and light-ion induced fusion, the SPIG has improved the mass-separated ion yields by a factor of typically 4 to 8. Correspondingly, the transmission efficiency of both systems has been studied in simulations with and without space charge effects. The transport capacity of the SPIG has been experimentally determined to be 10^12 ions/s before space charge effects start to take effect. A direct comparison with the simulation has been made using data obtained via light-ion fusion evaporation. Both experiment and simulation show an encouraging agreement as a function of current extracted from the ion guide.