Fission yield studies with SPIG-equipped IGISOL : a novel method for nuclear data measurements

Abstract

This thesis work consists of two sections. In the first section, the development of a so-called Laser Ion Source Trap (LIST) device is described. The LIST device is based on a double SPIG (SextuPole Ion Guide) system, providing the possibility to improve the elemental selectivity of the IGISOL method via highly discriminative laser ionization occurring outside the ion guide. The improved selectivity enables the production of isotopically pure beams. The double SPIG can be used without laser ionization and replaces the conventional skimmer electrode. In this work, the SPIG is compared to the skimmer and is shown to remarkably improve both the efficiency and beam quality of the IGISOL facility. The second section introduces a novel method for isotopic fission yield measurements. Accurate fission product yield data are important in many fields of physics. Previous experimental techniques are either limited to certain mass regions of the fission products, or lead to inaccurate and/or time consuming yield deduction. The technique described in this work is a successful combination of the universal IGISOL method and an unambiguous isobaric purification of the JYFLTRAP facility. This combination is able to provide pure samples of almost any isotope produced in fission. These samples are directly counted using a highly sensitive MCP - detector, significantly shortening the measurement time as compared to traditional detection methods such as a gamma-spectroscopy.