1. Duncan J S Johnson

2.  Determine nuclear properties by observing HFS via collinear laser spectroscopy.  Currently in the process of studying manganese.  Possible to study chromium using similar method:

3.  Mn and adjacent isotope chains do not show ‘kink’ in 2-neutron separation energies.  However the change in nuclear mean- squared radius shows expected contraction:

4.  New cyclotron is dedicated to IGISOL line.  Beam-line is being rebuilt and upgraded.

5. A few weeks ago:

7.  Accelerated Beams reduces Doppler broadening down to natural widths:  Cooled ions means slower beams can be used.  However Cooler- Buncher is set at high voltage to receive high energy ions from the IGISOL.

8.  CEC placed inside:  Neutralisation means transitions are less energetic.  Combine with HV box for state- selective charge exchange:  High voltage region insulated by 25% glass filled PTFE pipe segments.  HV platform to decelerate ions:  Increased pumping time and time in LCR.

9.  Mini-RFQ trap placed inside:  Storage: Bunching and pumping.  Photo-chemistry to remove contaminants. Hf + + O 2  HfO +  “Elevator” to change ion energy.  Traps passing ions between them to build up ions.

10.  New beam-line means new beam trajectory needs to be calculated.  Beam-line built using existing components; possible problems.  Using ion optics simulator SIMION ®.  User programs:  changing potentials (eg: RFQ)  charge-exchange  randomise initial ion conditions  etc...  SIMION is being used to optimise transmission through the beam-line and to indicate any possible problems.  Existing line at ISOLDE modelled and highlights known issues.

11.  Minor problems: Parallel plates block beam.  Solution: Simple adjustment of apparatus.

12.  Major problems: Fringe fields causing the ion beam to misalign.  Solutions: New apparatus such as parallel plates and quadrupole doublet.

13.  Similar apparatus: High voltage CEC

14.  New Lab is under construction.  Dedicated cyclotron.  Upgraded beam-line.  Upgrades will allow study of previously unavailable isotopes and give greater flexibility to the beam-line.  Decelerated beams.  State-selective charge exchange.  Secondary trap.  New beam trajectory needs to be calculated and optimised using SIMION, and any indicated problems dealt with.

16.  P. Campbell  B. Cheal  J. Billowes  K. T. Flanagan  D. J. S. Johnson