Producing Radioactive Ion Beams
through the ISOL Method:
Advances, challenges and opportunities.

Mark Huyse
KU Leuven, Instituut voor Kern- en Stralingsfysica, Belgium

Mark Huyse

ARIS II, Tokyo, 1 – 6 June 2014

1/20

How far can we go with the ISOL method?

Production of intense and pure radioactive ion beams
Manipulation of ISOL beams
Integration with experimental set-ups

Mark Huyse

ARIS II, Tokyo, 1 – 6 June 2014

2/20

Production of intense and pure radioactive ion beams
Choice of the reaction
 intensity of primary beam target thickness cross section selectivity of the reaction
Purification in flight (IF) or after stopping

Spallation
FusionFissionFragmentation

thick target <=> thin target

ISOL

solid catcher
diffusion out of the target or catchertransfer to the ion source
Z & T1/2 dependence

ion source
Z selection

Mark Huyse

ARIS II, Tokyo, 1 – 6 June 2014

mass
separator
3/20

The release problem

85

courtesy B. MarshMark Huyse

ARIS II, Tokyo, 1 – 6 June 2014

4/20

Production of intense and pure radioactive ion beams
Spallation
FusionFissionFragmentation

Choice of the reaction
 intensity of primary beam target thickness
 cross section
 selectivity of the reaction
Purification in flight (IF) or after stopping
ISOL
thin target
ISOLgas catcher
ion survival- IGISOL- Gas catchers

ion source
Z selection

Mark Huyse

ARIS II, Tokyo, 1 – 6 June 2014

massseparator
5/20

Production: Target Developments => brute force

Higher in primary beam intensity (now 100 A at ISAC)
From kW towards MW on target

LIEBE: a study for a Pb-Bi loop target

Mark Huyse

NaF salt target for intense production of 18Ne

ARIS II, Tokyo, 1 – 6 June 2014

6/20

Production: Target-Ion-Source developments: focused approachRelease=> molecular sidebands
HELICON-type ion source for molecular sidebands

50-fold enhancement of 10-11CO+with nanostructured CaO target

Fast release =>T1/2=> nanostructured materials

CaO
fast diffusing
lower temperatures

Selectivity

Mark Huyse=> shorter T1/2=> higher reliability=> lasers and physico-chemical properties

ARIS II, Tokyo, 1 – 6 June 2014

7/20

Production: Gas stoppers for high-energy recoils
Challenge: large stopping volume is needed=> minimize neutralization & diffusion losses and delay times using electric fields- Linear gas stoppers
M. Wada, NIM B317 (2013) 450-456

see Guy Savard on CARIBU- Circular gas stoppers
S. Schwarz et al., NIM B317 (2013) 463-467- Challenges: Beam purity and high intensity=> cryogenic cell
W. R. Pla et al., NIM B317 (2013) 457-4612

Mark Huyse

ARIS II, Tokyo, 1 – 6 June 2014

8/20

Production: Resonant Ionization Laser Ion Source (RILIS)

efficiency is dependent on the used transitions- cross section- available energy for that transition- temperature dependence (metastable states)- pressure dependence- ...

courtesy I. Moore

Mark Huyse

Otten E.W., Treatise on Heavy Ion Science vol 8 (1989) 517
Billowes J. and Campbell P, J. Phys. G21 (1995) 707
Kluge H-J., Nörtershäuser, W. Spectrochim. Acta B 58 (2003) 1031
Kluge H-J., Hyperfine Interact. 196 (2010) 295
Cheal B. and Flanagan K., J. Phys. G. 37 (2010) 113101

ARIS II, Tokyo, 1 – 6 June 2014

9/20

Production: The Z selectivity of the RILIS approach
Possible sources of contamination => Solution- Hot cavity- Thermo-ionization=> LIST-=> ?

Activity on RFQ rods

B. A. Marsh et al., NIMB 317 (2013) 550-556
D. A. Fink et al., NIMB 317 (2013) 417-421
J. Lassen et al., Rev. Sci. Instrum. 85 (2014) 033309- Gas cell
- surviving ions
- Re-ionization by radiation- Ionization in the decay

Dual chamber=> Ion collector
LIST

Yu. Kudryavtsev et al., NIMB 267 (2009) 2908-2917- Activity on RFQ rods=> ?

- Gas jet
- Activity on RFQ rods=> ?

T. Sonoda et al., NIMB 267 (2009) 2918-2926
Yu. Kudryavtsev et al., NIMB 297 (2013) 7-22
I. D. Moore et al., NIMB 317 (2013) 208
Mark Huyse

ARIS II, Tokyo, 1 – 6 June 2014

10/20

Manipulation of ISOL beams
 cooling=> improving the ion optical properties
 bunching mass separation => optimal mass-resolving power while keeping theefficiency (dipoles M/M ~20.000; cyclotrons and MR-TOF’s higher) neutralisation=> for laser applications

 polarisation=> solid-state physics, fundamental physics

 deceleration=> injection in traps

 post acceleration => reactions, implantation, …

Mark Huyse

ARIS II, Tokyo, 1 – 6 June 2014

11/20

Manipulation: Post acceleration
Challenge: higher charge state is needed for efficient post acceleration=> stripper foils
TRIUMF / ISAC=> Electron Cyclotron Resonance Ion Source (ECRIS)LLN
TRIUMF / ISACGANIL / SPIRAL=> Electron Beam Ion Source or Trap (EBIS/T)
ISOLDE
NSCL+ more to comeMark Huyse

ARIS II, Tokyo, 1 – 6 June 201412/20

Integration with experimental set-ups
 decay setups
 different implantation conditions (temperature, material, e.m.
fields, … ) different detectors
 laser setups
 ion traps
 atom traps
 reaction chambers spectrometers storage rings

Strong coupling between the production, the manipulation and the experiments

Mark Huyse

ARIS II, Tokyo, 1 – 6 June 201413/20

Integration: In-Source Laser Spectrocopy

B. A. Marsh et al.
NIMB 317 (2013) 550-556
see also Jens Lassen

ion curre nt (p A)

ion current (pA)

principal quantum number
30361020IP(At) = 9.31751(8) eV

10S. Rothe et al., Nature Com. (2013) DOI 10.1038

01615016 20016250

16 30016350-1wa venu mber (cm )wavenumber
Mark Huyse

ARIS II, Tokyo, 1 – 6 June 2014

14/20

Integration: In-Source Laser High-Resolution Spectrocopy
From 3.5 GHz to 450 MHz due to T↓ & p ↓3.5 GHz450 MHz

Y. Kudryavtsev et al.; NIMB297 (2013) 7-22

Mark Huyse

ARIS II, Tokyo, 1 – 6 June 2014

15/20

An integrated approach
Towards
MRTOF

 unwanted ions further
collected
 supersonic jet:extended atom beam, low unwanted ions collected=>reaction products stopped inpressure, low temperature< 500 mbar Ar broadband in-gas cell ~ 200 MHZ resolutionionization to find the laser spectroscopy=> small cell fast evacuation
resonances Isomeric purification
R. Ferrer et al., NIMB 317 (2013) 570-581 REGLIS@S3 see also H. Savajols=> pre-separation by ionization zone shielded fromlow-energy in-flight separators
stopping zone

Mark Huyse

ARIS II, Tokyo, 1 – 6 June 2014

16/20

Integration: Coupling to storage rings
ERIS for SCRIT at RIKEN

M. Wakasugi et al., NIMB 317 (2013) 668-673

Mark Huyse

M. Grieser et al.
Eur. Phys. J. Special Topics 207 (2012) 1–117

ARIS II, Tokyo, 1 – 6 June 201417/20

Outlook: after half a century still alive and kicking!
An ISOL facility: stopped radioactive nuclei, reaccelerated and mass separated

Existing
IGISOLMARA IRIS

In progress
LISOL
NSCL
ISAC
CARIBUGALS CARR-ISOL

ALTO
SPIRALSHIP
TRIGA
REGLIS@S3
ISOLDEKOBRASPESTEXAS A&M
ERIS

BRISOLPALISKISSSLOWRIJAERI-ISOL

VECC ANURIBMark Huyse

ARIS II, Tokyo, 1 – 6 June 201418/20