High Power Target Studies at CERN-ISOLDE Tania M. Mendonca, Melanie Delonca, Veronique Ghetta, Etam Noah, Thierry Stora

Outline Molten target loops for radioactive ion beam (RIB) production Molten salt for neutrino physics and medical applications Lead Bismuth eutectic target loop – the LIEBE project Neutron converter studies at ISOLDE Summary 2

Molten target loops for radioactive ion beam (RIB) production Latvia Molten Pb/Bi loop Final Report of the EURISOL Design Study 2009, J. Cornell Ed., GANIL Pb/Bi shower at diffusion chamber (at the exit of interchangeable grid) Fragmentation of the molten material into a shower-type droplets spray (droplets, jets, films) Reduction of the diffusion length Increase of released fraction of produced RIBs Accommodation of high beam powers For RIB production, molten materials can provide the highest intensities but suffer from long diffusion times.

Molten salt loop for neutrino physics 4 Linac ISOL target Linac 160 MeV Molten salt loop target Pulsed ECR SPS PS Rapid Cycling Synchrotron Linac 100 MeV Production Ring Detector: Water Cherenkov in Fréjus tunnel (baseline) Decay ring, γ =100 Circunference 6900 m B ρ ~500Tm ν e -beam Baseline, low-Q isotopes Optional, high-Q isotopes New instalations in red 6 He 18 Ne Isotope collection Beta Beams Facility 160 MeV 1.1 MW 2.1 L/s NaF:LiF at 700ºC Dim:7.5x24x15cm Dim:40x15x15cm Transfer line to ion source dump protons 18 Ne Diffusion chamber Irradiation cell Heat exchanger pump Proposal inspired from 18 F production for PET imaging: NaF target loop ( 23 Na(p,X) 18 Ne, 19 F(p,2n) 18 Ne) P. Zuchelli, Phys. Lett. B 532, 166 (2002) M. Benedikt et al, Eur. Phys. J. A, 47, 24 (2011) T.M. Mendonca et al., J. of Phys.: Conf. Series 408, (2013)

A step towards the validation of the concept: static unit test at ISOLDE 5 Prototype molten NaF:LiF static target unit and components: (1)Salt container, (2) condensation chimney, (3) cold transfer line, (4) ion source, (5) copper blocks Target in hot haynes oven Online test at ISOLDE/CERN with 1.4 GeV Proton beam

18 Ne production and release 6 T.M. Mendonca et al., Nucl. Instr. Meth. B 329, 1 (2014)

Ne diffusion 7 T.M. Mendonca, Proc. IPAC, JACoW, Dresden 2014, T.M. Mendonca et al., in preparation First determination of the diffusion coefficient of Ne in NaF:LiF salts Release favoured by smaller sizes 96% release for 100 µm droplet Predicted yields of 1.9x10 7 ions/µC for 1.4 GeV, 1.1 kW Predicted intensities of ions/s for 160 MeV, 1.1 MW D(Ne) in NaF:LiF is 8 orders of magnitude higher than oxide targets (CaO, Al 2 O 3 with D~ m 2 /s)

Molten salts in medical applications 8 R.S. Augusto et al., Nucl. Instr. Meth. B(2016) T.M. Mendonca et al., CERN-ACC-NOTE Ttarget=720C Extraction in molecular form is favoured. Record yields of 8x CO/µC. Yield improvement by two orders of magnitude. Combination of molten salt targets with ISOL technique as alternative method for production of radiotracers for nuclear imaging/treatment. Main Parameters for 11 C ion production. Carbon yields and comparison with best figures from oxide targets at ISOLDE

LBE target loop - the LIEBE target 9 E. Noah et al., Latvia Molten Pb/Bi loop Final Report of the EURISOL Design Study 2009, J. Cornell Ed., GANIL Pb/Bi shower at diffusion chamber (at the exit of interchangeable grid) LiEBE Liquid Eutectic Lead Bismuth loop target for Eurisol

LIEBE target Prototype to be tested at ISOLDE in November See presentation by Melanie Delonca, Wed 12April at 12h20 Diffusion chamber Heat exchanger Electromagnetic pump

11 Molten target loops MaterialEnergy [GeV]Power [kW]RIBsProject LBE HgEURISOL LBE HgLIEBE NaF:LiF Ne, 11 C Beta Beams/ PET isotopes NaF:LiF NeBeta Beams Proposed molten target loops, driver beam characteristics and respective RIBs of interest.

Proton to Neutron converters at ISOLDE 12 Standard ISOLDE configuration Design and Optimizations R. Luis, et al., Eur. Phys. J. A. 48 (2012) 90 A. Gottberg, T.M. Mendonca, et al., NIMB 336 (2014) 143–148 Validation of the concept Isotope yield results: See Joao Pedro Ramos Poster

Summary Combination of high material densities and good heat transfer properties – molten materials as candidates for high power applications. Circulating loop for MW beam powers. For RIB production, fragmentation in a diffusion chamber for release fraction and beam intensity improvement. On-line validation of LBE target loop – LIEBE target – foreseen in November Thank you for the attention!