workshop on radioactive ion beam purification cern, sep 4 th 2007 cara jost

Beam development for the Center of Excellence for RIB Studies for

Stewardship Sciences –

Target and ion source for screening studies at Oak Ridge

Workshop on Radioactive Ion Beam Purification

CERN, Sep 4th 2007

Cara Jost

Holifield RIB Facility @ ORNLAccelerators:

Cyclotron ORIC

Tandem (25MV)

RIB production:• RIB platform• High Power Target Lab• On-line Test

Facility UNISOR

50 MeV protons, 12 µA

50 MeV protons, 20 µA

40 MeV protons, 50 nA

On-line Test Facility UNISOR

• Tandem beam: protons (40 MeV, max. 50 nA); heavy ions

• Ion source: EBPIS or KENIS

• TIS corresponds to HRIBF production platform → yields scalable

• Moving tape station + γ-detector

• Low radiation → TIS accessible shortly after irradiation

Modified TIS for screening experiments

• Transfer line: modified copy of ISOLDE prototype #1

• Ion source: standard EBPIS (MK5)

• Cathode current connected at end of transfer line

• Opening in the line to change trapping materials

• Additional line heating to vary temperature

Screening studies: Trapping materials

Retention time on trapping material:• Material dependence: chemical composition, surface and

bulk structure• Temperature dependence (mostly)

Ceramic materials: • Wide range of chemical compounds

and structures• High temperature stability• Low vapor pressure

Screening studies: Experiments

Materials to use: - Tantalum (as base line)- Quartz (comparison with ISOLDE data)- Aluminum oxide (Doping?)- Silicon carbide

Elements to be surveyed:- Sr / Rb (→ (d,p) experiments)- Ag to Cs

Screening studies: Experiments

Data:

- Yield measurements (different half-lives)- Hold-up times- Changes in yields / hold-up times with line temperature

128-Sn holdup from UCx target

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

0 10 20 30 40 50 60

time (min)

46 keV

75 keV

152 keV

482 keV

Fit

beam off

↓

beam on

↓

beam off

↓

Ken Carter, Andreas Kronenberg, Charles Reed

Dan Stracener

Oliver Arndt, Karl-Ludwig Kratz

Elian Bouquerel, Thierry Stora

Thanks to: