Moderators and CREMLIN Plus Ken Andersen Neutron Instruments

Moderators and CREMLIN Plus Ken Andersen Neutron Instruments Division European Spallation Source ERIC 2019 -04 -03

The CREMLIN Project Connecting Russian and European Measures for Large-scale Research Infrastrucures • Improving and strengthening European-Russian collaboration in Research Infrastructures – Pathfinding project to identify areas and strategies for concrete collaboration • Funded by EU Horizon 2020 • 8 Work Packages over 3 years (2015 -18) – – – – WP 1 Management WP 2 Exchange Platform WP 3 NICA – ion beams and heavy ion physics WP 4 PIK – neutron sources WP 5 SSRS-4 – photon science WP 6 XCELS – high power laser research WP 7 STC – lepton colliders WP 8 Communication, Dissemination, Education, Training, Innovation 2

CREMLIN Plus Continuation of CREMLIN, including real collaborations • 3 “Dimensions” over 4 years 2020 -2024 – Collaboration with Russian megascience projects (WP 2 -WP 8) – Access (WP 9) – Staff Exchange (WP 10) • 10 Work Packages over 4 years – – – – – WP 1 Management (0. 7 M€ DESY) WP 2 Collaboration with NICA (4. 6 M€ FAIR, JINR, U. Tübingen, WUT, Wigner) WP 3 Collaboration with PIK (4. 4 M€ Jülich, PNPI, LLB, ESS, ILL, BNC, HZG, TUM, JINR, SPSU, UNIMIB) WP 4 Collaboration with SSRS-4 (4. 4 M€ NRC KI, ESRF, DESY, INFN, E-XFEL) WP 5 Collaboration with SCT (2. 4 M€ BINP, CERN, INFN, LAL Orsay, IJS, U. Giessen, IHEP) WP 6 Collaboration with XCELS (1. 3 M€ IAP, CEA, ELI-DC, LASERlab) WP 7 Horizontal activities: Joint developments (1. 3 M€ IPHC, FAIR, JINR, U. Frankfurt/M, CERN, DESY, BINP, KINR) WP 8 Access of EU scientists to Russian research infrastructures (2. 3 M€ ICISTE, DESY, NUST MISIS, NRC KI) WP 9 Human Resources development (3. 0 M€ UNIMIB, NUST MISIS) 3 WP 10 Dissemination and Outreach (0. 4 M€ DESY)

CREMLIN Plus Tasks in Work Package 3 • Task 3. 1 High-brilliance cold neutron source (FZJ, NCRKI-PNPI, MTA EK) – Design of PIK 2 nd cold neutron source for installation in 2024 – Implement ESS moderator developments • Task 3. 2 Bi-spectral neutron extraction system (FZJ, NCRKI-PNPI, MTA EK) – Design bi-spectral beam extraction and guide system for 2 nd cold source • Task 3. 3 Development of advanced Very Cold Neutron (VCN) source (ILL, NRC KI-PNPI, JINR, PTI, UCA, UNIMIB, ESS) – Development of VCN moderator and reflector materials – Development of modelling tools – Design, construction and test of prototype at ILL/JINR • Task 3. 4 General blueprint for instrumentation at PIK (NRCKI-PNPI, FZJ, TUM, HZG, CEA-LLB) – Design of new Russian and German instruments, including integration with moderators, beam extraction and guides 4

CREMLIN Plus Tasks in Work Package 3 • Task 3. 5 Prototype of advanced polarized neutron diffractometer for PIK (CEA-LLB, NRCKI-PNPI) – Design and construct working prototype single-crystal diffractometer at PIK • Task 3. 6 Establishing the scientific infrastructure at ICNR (NRCKI-PNPI, FZJ) – Management and organisation of science programme at PIK – Set up SAC, and instrument and technical subcommittees • Task 3. 7 Instrument-specific education and training programs for engineers and scientists (NRCKIPNPI, FZJ, SPSU, HZG, TUM, CEA-LLB, ILL, MTA EK, ESS) – Training young Russian engineers and scientists in workshops, schools, training courses • Task 3. 8 User System (TUM, NRCKI-PNPI, JINR, ILL) – Establishing international user access • Task 3. 9 Support strategic coordination of PIK (NRCKI-PNPI, FZJ, JINR, PTI, SPSU, HZG, TUM, CEALLB, ILL, UCA, MTA EK, UNIMIB, ESS) – Support PIK project management and coordination 5

Task 3. 3 VCN Developments Task plan 2020 Model calculations of VCN yields of converter/reflector VCN source Design, construction, test of cryogenic device and reflector Setup VCN source prototype, combining equipment at ILL and JINR Experiments with the prototype at ILL and/or JINR 2021 2022 2023 2024 ESS ILL JINR CF PTI ILL JINR 6

ESS Target 7

ESS Moderators 8

ESS Moderators Moderator: slows down fast neutrons – converts them from fast neutrons to slow neutrons Possible VCN converters: liquid hydrogen, solid deuterium, deuterated methane, oxygen clathrates Reflector: reflects slow and intermediate neutrons back into the moderator – maximises escape through the viewed surface Possible VCN reflectors: diamond nanoparticles, intercalated graphite 9

ESS moderators thermal cold 10

ESS moderators thermal cold very cold 11

ESS moderators thermal cold very cold Development needs: VCN moderator materials VCN reflector materials 12

Diamond nanoparticles as neutron reflectors Cold neutron reflector (E<5· 10 -3 e. V) • Small scattering probability • Small scattering angle • Deep penetration Possible to have an efficient reflector only at glancing angle of neutron incidence Very cold neutron reflector (E<10 -4 e. V) 1 n 1 n 0 0 1 n 0 • Large scattering probability • Large scattering angle • Small penetration Possible to have an efficient reflector at any incident angle Courtesy E. V. Lychagin et al. 13

Neutron Reflectors Diamond Nanoparticles Theory Experiment Supermirror Graphite Fermi potential Courtesy E. V. Lychagin et al. 14

Neutron Reflectors Diamond Nanoparticles Theory Experiment Supermirror Graphite Fermi potential Courtesy E. V. Lychagin et al. 15

Neutron Reflectors Diamond Nanoparticles Theory Experiment Supermirror Graphite Fermi potential Courtesy E. V. Lychagin et al. 16

Neutron Reflectors Intercalated Graphite Experiment Supermirror Graphite Fermi potential Courtesy E. V. Lychagin et al. 17

Neutron Reflectors Intercalated Graphite CREMLIN Plus development Experiment Supermirror Graphite Fermi potential Courtesy E. V. Lychagin et al. 18

Cut through target station Beamport S 11: perpendicular to proton beam 19

Cut through target station Beamport N 5: FREIA 20

Envelope for inner shielding TCL sector focal point 197 152 137 122 TCS R=2000 77 0 -77 -122 -360 MR plug all coordinates in TCS 21

ESS Moderators 22

ESS Moderators ? 23

ESS Moderators • UCN source • VCN source ? – Up to 240 mm viewable height • Favour area-integrated brightness • General-purpose moderator available to all – n-nbar – Directional • Dedicated moderator for single beamline 24

Long-term interest for ESS Part of upgrade plan • Upgrade plan for ESS – More instruments on the main target station (rather than new target station) – When we have reached nominal performance (22 instruments and 5 MW): >2030 – Moderator-Reflector plug will anyway need replacement every ~2 years @5 MW • An optimised VCN source in the lower moderator position? – – Intensity gains of factor ~10 for neutrons around 10 Å or more Small-angle neutron scattering (better versions of LOKI and SKADI) Neutron spin-echo: huge increases in energy resolution Particle physics: neutron lifetime, neutron EDM, dark matter, … 25