Recent developments at ISOL-based facilities. Piet Van Duppen KU Leuven, Belgium

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1 Recent developments at ISOL-based facilities Piet Van Duppen KU Leuven, Belgium 1

2 Introductory remarks on RIB research Target materials Ion Sources Laser Resonance Ionization Ion manipulation Hg laser spectroscopy Charge Breeding Gas-cell based approach: S3 LEB Higher primary beam intensities: a note Conclusion and outlook see talk by P. Delahaye (developments at SPIRAL1) 2 Y. Blumenfeld, T. Nilsson T. and PVD, Physica Scripta T152 (2013)

3 Experimental RIB research Energy Charge-state breeding (ECR, EBIS) HIE ISOLDE SPIRAL Selectivity/Sensitivity Primary beam Production cross section / target material Efficiency Fast (reduce decay losses) Reliability Intensity Beam purification (laser ion source, MR-TOF, High Resolution Separator) Adapted Instrumentation (identification of reaction products, detection of weak signals) 3

4 Experimental RIB research Energy Universality Efficient, Selective and Fast Selectivity/Sensitivity Intensity Production mechanism Short half lives Gaps refractory-type elements 4 A. Gottberg,- NIMB 376 (2016) 8 ISOLDE yield database

5 Nano-Crystalline Uranium Carbide 2/3 of ISOL targets worldwide UCx Target materials SiC Ta uranium dioxide and dispersion mixing with multi-walled carbon nanotubes other fission targets other spallation targets 5 courtesy A. Gottberg A. Gottberg,- NIMB 376 (2016) 8

6 Resonance Laser Ionization Developments in the resonance laser ion source (> 50% beam time at ISOLDE) Target Hot Cavity Extractor Ion Source Mass separation 60 kv Experiments courtesy I. Moore Protons 1.4 GeV Target material - U Reaction products (neutral) Ions ISOLDE, JYFL, TRIUMF, GANIL, RIKEN,... 6 V. Fedosseev,- J. Phys. G. 44 (2017) K. Blaum,- Phys. Scr. T152 (2013) Kluge H-J., Hyperfine Interact. 196 (2010) 295 Cheal B.and Flanagan K., J. Phys. G. 37 (2010)

7 VADLIS RILIS inside a FEBIAD ion source Increased efficiency and selectivity RILIS coupled with liquid targets So far demonstrated for: Ga, Cd, Hg, Ba, Ba+, Sn, Mg Particle-in-cell model using VSim cathode anode Versatile Arc Discharge Ion Source (VADIS) 7 T. Day Goodacre,- NIM B 376 (2016) 39 courtesy B. Marsh, Y. Martinez

8 Multi-Reflection Time of Flight: mass measurements beam purification beam diagnostics ISOLDE, GSI, JYFL, GANIL, TRIUMF, MSU, RIKEN,... Anode Voltage Time-Of-Flight 8 V. Manea ISOLTRAP and R. N. Wolf,- NIMA 686 (2012) 82

9 Laser ionization spectroscopy of neutron-deficient mercury isotopes using VADLIS and MR-TOF isotope shifts charge radii N=104 9 Bonn,- PLB 38 (1972)

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 no Fr contamination! 10 Fink,- NIMB 344 (2015) 83, Phys.Rev.X5 (2015)

11 Inaccessible or problematic elements for ISOLDE RILIS 11

12 Mo(CO) 6 (Molybdenum hexacarbonyl) - Molecular breakup + ionization 1) Creation and transport of volatile molecules of refractory metals 2) Dissociation by laser pulse 3) Resonance ionisation before atom/wall collision 12

13 Charge breeding ECR and EBIS approaches cathode solenoid compression electron beam electron impact ionization ions Increased efficiency Shorter breeding times (higher electron current densities) Higher charge states Longer extraction times 13 courtesy F. Wenander

14 REX EBIS, ANL EBIS, MSU ReA EBIT, TRIUMF EBIS - ARIEL 34 Ar 15+ Breeding efficienty (%) 47 K Ar A/Q 14 R. Vondrasek, NIMB 376 (2016) 16 A. Lapierre Can. J. Phys. 95: (2017)

15 mbar Ar or He from S 3 in-gas-cell ionization gas cell EVRs Neutralized EVRs Photoions REGLIS SPIRAL2 In Gas Laser Ionization and Spectroscopy S3 S-shape RFQ λ 1,2 λ 2 λ 1 towards DESIR in-gas-jet ionization diff. pumping RFQ QMF (m/ m ~ 100) buncher MCP see talk M. Laatiaoui and A. Drouart Two lasers systems: TiSa and dye MR ToF MS (m/ m ~ 10 5 ) bender 10-2 mbar mbar 10-8 mbar towards Multi Purpose Room S3LEB Idenfification/detection system 15 Ferrer,- NIM B317 (2013) 570 Kudryavtsev,- NIM B297 (2013) 7

16 S3 High intensity heavy-ion LINAC: >10 pµa Super Separator Spectrometer (S3) N=Z nuclei (towards 100 Sn) and heavy and Super Heavy Elements 16 Kudryavtsev NIM B297 (2013), Ferrer NIMB317 (2014) and Nat. Comm. (2017)

17 Higher Primary Beam Intensity (comments by Bruce Marsh) 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 Maintain efficiency under high ion loads Reliable operation for many weeks Increased selectivity > isobar production > Radioactive inventory EURISOL challenges require coordinated community-wide target / ion source R&D 17 comments by Bruce Marsh at the EURISOL town meeting Leuven (2016)

18 Conclusion and Outlook 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 Thanks to: Bruce Marsh, Fredrik Wenander, Thierry Stora, Pierre Delahaye, Alex Gottberg 18