1

Recent developments atISOL-based facilities

Piet Van DuppenKU Leuven, Belgium

2

• Introductory remarks on RIB research• Target materials• Ion Sources

• Laser Resonance Ionization• Ion manipulation

• Hg laser spectroscopy• Charge Breeding

• Gas-cell based approach: IGLIS @ S3 LEB• Higher primary beam intensities: a note• Conclusion and outlook

Y. Blumenfeld, T. Nilsson T. and PVD, Physica Scripta T152 (2013) 014023

see talk by P. Delahaye (developments at SPIRAL1)

3

Energy

Intensity

Selectivity/Sensitivity

• Primary beam• Production cross section / target material• Efficiency• Fast (reduce decay losses)• Reliability

HIE ISOLDESPIRAL

• Beam purification(laser ion source, MR-TOF, High Resolution Separator)• Adapted Instrumentation(identification of reaction products, detection of weak signals)

Experimental RIB research• Charge-state breeding(ECR, EBIS)

4

Energy

IntensitySelectivity/Sensitivity

Universality

Gaps refractory-type elements

Short half lives

Production mechanism

Efficient, Selective and Fast

A. Gottberg,- NIMB 376 (2016) 8 – ISOLDE yield database

Experimental RIB research

5

• Nano-Crystalline Uranium Carbide

UCx

SiC

Ta

other spallation targets

other fission targets

courtesy A. Gottberg A. Gottberg,- NIMB 376 (2016) 8

Target materials

2/3 of ISOL targets worldwide

uranium dioxide and dispersion mixing with multi-walled carbon nanotubes

6

• Developments in the resonance laser ion source(> 50% beam time at ISOLDE)

V. Fedosseev,- J. Phys. G. 44 (2017) 084006K. Blaum,- Phys. Scr. T152 (2013) 014017

Kluge H-J., Hyperfine Interact. 196 (2010) 295Cheal B.and Flanagan K., J. Phys. G. 37 (2010) 113101

courtesy I. Moore

Resonance Laser Ionization

ISOLDE, JYFL, TRIUMF, GANIL, RIKEN,...

Experiments

Mass separation

Target Hot Cavity ExtractorIon Source

Reaction products(neutral)

IonsProtons 1.4 GeVTarget material - U

60 kV

7

• VADLIS — RILIS inside a FEBIAD ion source

Increased efficiency and selectivity

So far demonstrated for:Ga, Cd, Hg, Ba, Ba+, Sn, Mg

RILIS coupled with liquid targets

T. Day Goodacre,- NIM B 376 (2016) 39

Particle-in-cell model using VSim

courtesy B. Marsh, Y. Martinez

Versatile Arc Discharge Ion Source (VADIS)

anodecathode

8 V. Manea ISOLTRAP and R. N. Wolf,- NIMA 686 (2012) 82

• Multi-Reflection Time of Flight: mass measurements – beam purification – beam diagnostics

Ano

de V

olta

ge

Time-Of-Flight

ISOLDE, GSI, JYFL, GANIL, TRIUMF, MSU, RIKEN, ...

9

• Laser ionization spectroscopy of neutron-deficient mercury isotopes usingVADLIS and MR-TOF

Bonn,- PLB 38 (1972)

isotope shifts → charge radii

N=104

10

• High Selectivity RILIS — Laser Ion Source Trap (LIST)

• 2-5 orders of magnitude surface ion suppression in LIST mode

• Efficiency loss factor of ~20

Fink,- NIMB 344 (2015) 83, Phys.Rev.X5 (2015) 011018

no Fr contamination!

11

• Inaccessible or problematic elements for ISOLDE RILIS

12

• Mo(CO)6 (Molybdenum hexacarbonyl) - Molecular breakup + ionization

2) Dissociation by laser pulse

1) Creation and transport of volatile molecules of refractory metals

3) Resonance ionisation before atom/wall collision

13

Charge breeding – ECR and EBIS approaches

electron beam

solenoid

ions

compression

electron impact ionizationcathode

courtesy F. Wenander

• Increased efficiency• Shorter breeding times (higher electron current

densities)• Higher charge states• Longer extraction times

14 R. Vondrasek, NIMB 376 (2016) 16A. Lapierre Can. J. Phys. 95: 361–369 (2017)

REX EBIS, ANL EBIS, MSU ReA EBIT, TRIUMF EBIS - ARIEL

47K17+

34Ar15+

46Ar17+

Bre

edin

g ef

ficie

nty

(%)

2 3 4 5A/Q

15

REGLIS3 @ SPIRAL2

λ1,2λ2 λ1

towards DESIR

in-gas-cellionization

EVRsNeutralized EVRsPhotoions

in-gas-jetionization

gas cell S-shape RFQdiff. pumping

RFQQMF

(m/∆m ~ 100) buncher

MR ToF MS(m/∆m ~ 105)

MCP

bender

10-2 mbar 10-3 - 2.10-5 mbar 10-8 mbar

200 - 500 mbar Ar or He

fromS3

tow

ards

Mul

ti P

urpo

se R

oom

–S

3LE

B Id

enfif

icat

ion/

dete

ctio

n sy

stem

Two lasers systems: TiSa and dye

In Gas Laser Ionization and Spectroscopy (IGLIS) @ S3

Ferrer,- NIM B317 (2013) 570 Kudryavtsev,- NIM B297 (2013) 7

see talk M. Laatiaoui and A. Drouart

16

IGLIS @ S3 High intensity heavy-ion LINAC: >10 pµA Super Separator Spectrometer (S3) N=Z nuclei (towards 100Sn) and heavy

and Super Heavy Elements

Kudryavtsev NIM B297 (2013), Ferrer NIMB317 (2014) and Nat. Comm. (2017)

17

Maintain efficiency under high ion loads Reliable operation for many weeks Increased selectivity > isobar production > Radioactive inventory

comments by Bruce Marsh at the EURISOL town meeting Leuven (2016)

• Even at current on-line facilities, ion sources routinely operate up to an order-of-magnitude below specification

• Understanding how to safely regain this efficiency is the most cost effective means of increasing RIB output

• Existing ISOL ion sources appear to be not suitable for next generation high-power ISOL facilities

Higher Primary Beam Intensity (comments by Bruce Marsh)

EURISOL challenges require coordinated community-wide target / ion source R&D

18

• Substantial progress in ISOL-based facilities leading to new, more intense RIB with increased purity and improved ion beam properties

• Target materials• Laser ionization• Charge breeding• Ion manipulation• Gas-cell based systems

• Strong cross fertilization between TIS developments and developments in instrumentation (e.g. lasers, ion manipulation, MR-TOF,...)

• Further optimization of efficiency/selectivity and increase in primary production rate are crucial next steps

• This requires a coordinated, international action e.g. under the umbrella of EURISOL DF

Conclusion and Outlook

Thanks to:Bruce Marsh, Fredrik Wenander, Thierry Stora, Pierre Delahaye, Alex Gottberg