NA2: Thin actinide targets optimized for high intensity beams Purpose: Optimize the high power capability and durability of thin actinide targets (“thin” means 0.1 to few mg/cm 2, i.e. not ISOL targets) for neutron and charged-particle induced reactions. Benefits: Extended target lifetimes and increased primary/secondary beam intensities at existing European user facilities Organisation: Coordinated production and test of fissile and non-fissile actinide targets under reproducible conditions. Comparison of different target preparation techniques, backings and covers. Training activities: Workshop on thin actinide targets. Permanent link between target producers and target users. Hands-on experience for students and postdocs.

NA2 Participant Institutions 1. Institut Laue Langevin & LPSC Grenoble, F target production by electrolysis, electrodeposition and painting on-line target tests under intense neutron flux to measure temperature, fission product intensity and energy distribution 2. IRMM Geel, B target production by spray-painting, electrodeposition (and evaporation) 3. LMU Munich, D target production by evaporation (and sputtering) 4. IPN Orsay, F target production by electrodeposition, spray painting target characterization by RBS, alpha, gamma spectroscopy future: CACAO project: joint CNRS-IN2P3/CEA hot lab 5. GANIL Caen, F heavy ion irradiation for validation of dpa-lifetime-relation Target production in collaboration with Nuclear Chemistry Institute Mainz, LBL Berkeley and Radium Institute St. Peterburg. Open to other collaborators.

RBS cartography (1.5 mm step) 235 U target NA2: Actinide target production and characterization LMU IPNO IRMM

target thickness monitored on-line via width of fission product energy distribution target temperature distribution monitored by pyrometer and IR camera longterm studies (several weeks) possible NA2: On-line test of high power actinide targets  Additional losses due to: sputtering by fission products evaporation (e.g. for UF 4 ) diffusion into backing or cover loss of adhesion to backing Burnup of 235 U target in 5.5E14 n/cm 2 /s neutron flux n/cm 2 /s ≈ 88 p  A/cm 2 comparison to accelerator beams: simulate at LOHENGRIN long exposition to intense HI beams

NA2: Synergies with other NA or JRA “survival training” for actinide targets at ILL: very high neutron flux: 5.5E14 n/cm 2 /s nuclear heating up to ca °C extremely high radiation damage: ca. 50 dpa/day, equivalent to damage by 3  A/cm 2 340MeV 48 Ca beam on 238 U target, i.e. 100 times more intense than present accelerator beams We identified overlap/possible synergies with the following other LoIs: ShERN (NA12) ECOS (NA4 or JRA11) ISOL-AT (JRA1) We are ready to merge our LoI and contribute with our capabilities to any of these. We leave the decision to the EURONS2-proposal management team to select the best option for fitting it into the overall EURONS2 proposal.

mass-separated fission fragments, up to 10 5 per second, T 1/2 ≥ microsec. The LOHENGRIN fission fragment separator flux 5.5·10 14 n./cm 2 /s few mg fission target (0.1-1 mg/cm 2, few cm 2 ) several fissions/s