Targets & conversion to secondary radiation summary Chris Densham

the energy problem – a range of opinions green enthusiast: sun and wind offer plenty of energy, no nuclear, no fossil, skepticism on tech technology enthusiast: fast reactors, fusion etc. ; optimism about technologies contemplative: technological development is too fast, consequences not predictable, go slower! Fact information: David McKay, Sustainable Energy without the Hot Air withouthotair.com, talk: youtube.com/watch?v=-5bVbfWuq-Q

Technology progression What to build next? Years

Technology progression Years

Technology progression

Technology progression

Cold Source Brightness a Metric of Efficiency?

Some neutron flux numbers for SINQ Inside the cold D2 moderator 3.4 1013 n/cm2/s/mA Neutron Guide Entrance (towards Neutronenleiterhalle) 6.0-8.0 1010 n/cm2/s/mA End of Guides 5.0 108n/cm2/s/mA On sample (at 3 Å) ~105 -106n/cm2/s/mA Proton Detector Target

Conclusion Target Moderator Guides Instruments Shielding Accelerator A separate optimization of the different integral parts of a spallation neutron source is inefficient. All integral parts – starting from the proton beam distribution down to the neutron instrument - have to be seen as a chain of components and should be optimized accordingly. A large number of neutrons is «lost» due to the isotropicity of moderation  directional moderators Neutron instrument setup currently tend to remove a large portion of neutrons due to chopper etc. systems. Could one use those «unwanted» neutrons? Instrument design.

Muon Facilities in the world ISIS (pulse) J-PARC (pulse) TRIUMF (CW) PSI (CW) Country Japan U.K. Switzerland Facility J-PARC MUSE RAL ISIS PSI proton energy [GeV] 3.0 0.8 0.59 proton intensity [MW] 1.0 (Goal) 0.16 1.3 m+ [/s] (surface) 3108 (U line) 6105 3107 m- [/s] 1107 7104 2107 CW / Pulse Pulse (25Hz) Pulse (50Hz) CW 50 GeV Synchrotron (0.75 MW) 3 GeV Synchrotron (25 Hz, 1MW) Materials and Life Science Experimental Facility （Muon & Neutron) Linac (181MeV  400 MeV) Pulsed muon beam don't need to mind about the pileup. No limit for proton beam intensity, but a highly segmented spectrometer is needed for mSR.

In-Target Production Yield Example with 132Sn Studies of neutron-rich nuclei beyond the doubly magic 132Sn are of key importance to investigate the single particle structure above the N=82 shell closure and find out how the effective interaction between valence nucleons behaves far from stability TRIUMF-ISAC CERN-ISOLDE IBS-RISP LNL-SPES EURISOL ARIEL FRIB p e- U Energy [MeV] 500 1000-1400 70 40 1000 50 47600 Intensity [µA] 100 2.5 1,000 200 10,000 5,000 Power in target [kW] 3 8 90 In-target Production yield 132Sn [pps] 5e10 to 1.5e11 for 10 μA ~1e10 (6e8 delivered) ~2e9 1.6e9 3e11 @ 0.5 GeV 3.9e9 1.4e7* Normalized in target production yield [pps/µA] 5e9 to 1.5e10 4e9 2e6 8e6 3e9 3.9e5 3e3 * * Already accelerated! F. Pellemoine, February 29 2016 Proton Driver Efficieny Workshop

Motivations for ‘Figures of Merit’ End-to-end simulations of accelerator driven facilities highly sophisticated & complex Computationally expensive – e.g. genetic algorithm ‘Black box’ type output Can be difficult to identify ‘design guidelines’ ‘Listen to the robot’ for the answer Useful to have a tool that (ref R.Zwaska) : Can factorise problems – orthogonal to genetic algorithm Is readily understood Can apply to a distribution Also useful to have a tool to compare reliability (materials or engineering issues)