B. Tordoff

Development of a laser ion source at IGISOL

FURIOS, the Fast Universal laser IOn Source, is under development at the IGISOL (Ion Guide Isotope Separator On-Line) mass separator facility in Jyvaskyla, Finland. This new laser ion source will combine a state-of-the-art solid state laser system together with a dye laser system, for the selective and efficient production of exotic radioactive species without compromising the universality and fast release inherent in the IGISOL system. The motivation for, and development of, this ion source is discussed in relation to the programme of research ongoing at this mass separator facility.

Off-line studies of the laser ionization of yttrium at the IGISOL facility

Abstract A laser ion source is under development at the IGISOL facility, Jyvaskyla, in order to address deficiencies in the ion guide technique. The key elements of interest are those of a refractory nature, whose isotopes and isomers are widely studied using both laser spectroscopic and high precision mass measurement techniques. Yttrium has been the first element of choice for the new laser ion source. In this work, we present a new coupled dye–Ti:Sapphire laser scheme and give a detailed discussion of the results obtained from laser ionization of yttrium atoms produced in an ion guide via resistive heating of a filament. The importance of not only gas purity, but indeed the baseline vacuum pressure in the environment outside the ion guide is discussed in light of the fast gas phase chemistry seen in the yttrium system. A single laser shot model is introduced and is compared to the experimental data in order to extract the level of impurities within the gas cell.

Nuclear charge radii and electromagnetic moments of radioactive scandium isotopes and isomers

Collinear laser spectroscopy experiments with the Sc+ transition 3d4s 3D2 → 3d4p 3F3 at λ = 363.1 nm were performed on the 42–46Sc isotopic chain using an ion guide isotope separator with a cooler-buncher. Nuclear magnetic dipole and electric quadrupole moments as well as isotope shifts were determined from the hyperfine structure for five ground states and two isomers. Extensive multi-configurational Dirac–Fock calculations were performed in order to evaluate the specific mass-shift, MSMS, and field-shift, F, parameters which allowed evaluation of the charge radii trend of the Sc isotopic sequence. The charge radii obtained show systematics more like the Ti radii, which increase towards the neutron shell closure N = 20, than the symmetric parabolic curve for Ca. The changes in mean-square charge radii of the isomeric states relative to the ground states for 44Sc and 45Sc were also extracted. The charge radii difference between the ground and isomeric states of 45Sc is in agreement with the deformation effect estimated from the B(E2) measurements but is smaller than the deformation extracted from the spectroscopic quadrupole moments.

Laser Ion Source Development at IGISOL

A new laser ion source is under development at the IGISOL (Ion Guide Isotope Separator On‐Line) mass separator facility in Jyvaskyla, Finland. Two laser systems have been installed to provide access to as broad a range of elements as possible. One system uses well‐known dye laser technology, the other uses solid state pump and titanium sapphire lasers. Several techniques are being pursued to improve both the isobaric purity and efficiency of exotic radioactive beams. One method uses pulsed lasers to ionize atoms after they have flowed out of the gas volume, within a radio‐frequency sextupole (SPIG) guide. This is a variation of the so‐called Laser Ion Source Trap (LIST) method and will be discussed in these proceedings.