BERLinPro
BERLinPro A Generic ERL project
Andreas Jankowiak Helmholtz-Zentrum Berlin
Verbundforschungsworkshop TU Darmstadt
A. 31.08.2011Jankowiak, Workshop Verbundforschung, 31.08.2011 1 Helmholtz-Zentrum Berlin: Science with photons + neutrons
HZB: Member of the Helmholtz Association like DESY, KIT/ANKA, GSI Wannsee: Adlershof: Hahn-Meitner Institut merger 01.01.2009, BESSY GmbH restructuring process Research Reactor BERII Light Sources BESSY II + MLS starts ~800 employees ~ 300 employees MLS
BESSY II
BER II
A. Jankowiak, Workshop Verbundforschung, 31.08.2011 2 HZB: Accelerator Physics and Technology
tasks: • operation, modernization, upgrade BESSY II and MLS • new concepts (BERLinPro) • Accelerator Research and Development Initiative HGF
- Institute for Accelerator Physics (G-I3) - Department Accelerator Operation (NP-A3) A. Jankowiak - Institute SRF – Science/Technology (G-I4) Jens Knobloch - Young Investigator Group: ERL Design (G-N1) Aleksander Matveenko, started 01.04.2010 A. Jankowiak, Workshop Verbundforschung, 31.08.2011 3 The idea
• high average („virtual“) beam power • outstanding beam parameter (up to A, many GeV) • single pass experiments • mature technology – many user stations • high flexibility • resonant system • low number of user stations interaction experiment ↔ ring • limited average beam power (< LINEAR ACCELERATOR ID X-Rays STORAGE Source ID RING IP IP X-Rays ENERGY RECOVERY LINAC IP ID X-Rays Main Linac Source Dump high average beam power for single pass experiments, A. Jankowiak, Workshopexcellent Verbundforschung, beam parameters, 31.08.2011 high flexibility, multi user facility 4 Applications of Energy Recovery Linacs • electron cooler for ion storage rings (nuclear and hadron physics) → future (high intensity beams with low transverse beam momenta in an energy range where electrostatic accelerators are no longer and storage rings not yet applicable) e.g. RHIC II Cooling of 100GeV/u Au • electron – ion collider with highest luminosities → future (as replacement of the limiting electron storage ring, 10-GeV linac comp. RF when beam beam limit is reached in e-ring) injector 0.12 km 0.17 km comp. RF 20, 40, 60 GeV e.g. 1.0 km eRHIC / BNL: ERL-ring high lumi version 2.0 km LHC p LHeC / CERN : LHC with 60GeV ERL dump 10, 30, 50 GeV 10-GeV linac IP 0.03 km 0.26 km A. Jankowiak, Workshop Verbundforschung, 31.08.2011 e- final focus 5 Applications of Energy Recovery Linacs • Basis for high power Free-Electron Laser (IR and UV) → presence (e.g. JLAB (since 2000), JAERI, Novosibirsk ERL) Future EUV source (13,5nm → 6.5nm) for next generation lithography 14kW IR power @ 1.6 m beam parameter achieved: energy: 160MeV av. Current: 9.1mA (1.5MW “virtual” beam power) emittance (norm.): 7 m min. pulse length: 150fs A. Jankowiak, Workshop Verbundforschung, 31.08.2011 6 Applications of Energy Recovery Linacs • search for new physics → future MESA, Mainz University (experiments at highest luminosities „dark photon search“ with internal gas targets at low beam energies and with minimum background conditions) ~ MESA 110MeV, 10mA cw Internal Target, L ~ 1035 s-1 cm-2 (courtesy: Kurt Aulenbacher, Mainz) • Compton sources, homeland security, nuclear waste management , ... A. Jankowiak, Workshop Verbundforschung, 31.08.2011 7 ERL as next Generation Multi-GeV, Multi-User SR-Source Combines the twodump worlds of storage rings and linacs electron source • with energy recovery: ~100mA @ many GeV possible (x 10) main linac: several GeV • always “fresh” electrons (no equilibrium) small emittanz (1 m rad norm. = 170pm rad@3GeV) (x 1/10) high brilliance ( x 100 - 1000) short pulses ( ps and shorter) • free choice of polarisation • 100% coherence • real multi-user operation at many beam lines + Flexible modes of operation (high brilliance, short pulse, different pulse patterns) adaptable to user requirements! A. Jankowiak, Workshop Verbundforschung, 31.08.2011 8 Still many open questions Electron source: high current , low emittance (100mA – A) cw / norm < m rad ) not yet demonstrated Injector: 100mA @ 5 – 10MeV = 500 – 1000kW beam loading (coupler, HOM damper) Main-Linac: 100mA recirculating beam Beam Break Up, Higher Order Modes, highest cw-gradients (>15MV/m) with high quality factor reduce cryo costs Beam dynamics: recirculation, flexible bunch compression Control of beam loss dark current, beam halo generation, collimation A. Jankowiak, Workshop Verbundforschung, 31.08.2011 9 BERLinPro Project Definition BERLinPro = Berlin Energy Recovery Linac Project 100mA / low emittance ERL demonstrator, including all the key aspects of large scale ERL An accelerator science and technology experiment generate a low emittance (1mm mrad) 1.5 MeV spent beam high current beam (100mA) 5-10 MeV 5-10 MeV merger section SRF photo beam dump SRF source booster main linac SRF modules recirculation 50 MeV beam manipulation High flux flexibility max. beam energy 50MeV 50MeV max. current 100mA nominal bunch charge 77pc up to ~10pC pulse length 2ps down to ~ 100fs Rel. energy spread ~10-4 range ~10-2 rep. rate 1.3GHz variable normalized emittance < 1mm mrad some mm mrad A. Jankowiak, Workshop Verbundforschung, 31.08.2011 10 Project goals Produce and accelerate an electron beam with emittance: < 1 mm mrad (normalized) current: 100mA cw (1.3GHz with 77pC bunch charge) pulse length: ~ ps at reasonable energy (50MeV ) in „user quality“ (low losses in recirculation) with energy recovery and stable and reliable operation → Facility for ERL beam tests and developments Acquire expertise to be prepared for future large scale projects A. Jankowiak, Workshop Verbundforschung, 31.08.2011 11 Project goals flexibility short bunches < ps (~100fs) higher bunch charges variable repetition rates → exploration of the parameter space (emittance, pulse length, energy spread, bunch charge) multi-turn energy recovery not financed, reserve space for second loop in building education of accelerator physicists and collaboration with German universities bachelor / master / PhD theses international collaboration share expertise and technology to speed up development A. Jankowiak, Workshop Verbundforschung, 31.08.2011 12 Challenges I • electron source with cathode and laser system staged approach for development of srf photo electron source Gun_0 → Gun_1 → Gun_2 already started, fully sc (Pb cathode film), first beam 21.04.11 demonstrator, beam dynamic nc cathode, CsK2Sb cathode beam dynamic, emittance, cathode performance lessons learned / high power • generate high power beam in booster Cornell booster design , adapt to our needs (couplers) A. Jankowiak, Workshop Verbundforschung, 31.08.2011 13 Challenges II • emittance compensation and preservation - merger design - 2d-emittance compensation scheme gun to end of linac - control of CSR effects • linac cavities for high current (HOMs, BBU) starting point CEBAF 5 cell with waveguide damper design started (Verbundforschung TU Do + U Ro) • control of beam losses “ERL beams do not occur in distributions named after dead mathematicians” Pat O'Shea, Univ. Maryland cited by D. Douglas, JLAB - dark current from gun and cavities - Halo from laser spot, non linear fields, bunch compression, CSR, ... - collimation schemes - diagnostics A. Jankowiak, Workshop Verbundforschung, 31.08.2011 14 Challenges III • high beam power BESSY II: 200C / a @ 1.7GeV typical BERLinPro: 300C / 1s @ 50-100MeV possible (30kW linac RF-power) new regime of operation (compared to storage ring) → radiation protection issues favor an underground bunker ground level 3m BERLinPro 50MeV 3m ground water level ~ 1.5m A. Jankowiak, Workshop Verbundforschung, 31.08.2011 15 Status: super conduction RF photo electron source First beam of photoelectrons from Pb cathode generated and accelerated at 21st Aptil 2011, < 2 years after project approval - Switch on RF, adjust phase, steer and focus with solenoid - lasercleaning of cathode measure QE of 5*10^(-4) at 260 nm measure therm. emiitance steering of laser beam spot on backwall of cavity -> QE maps First beam 21st April 2011 T. Kamps et al, Proc. of IPAC 2011 A. Neumann et all Proc. of IPAC 2011 A. Jankowiak, Workshop Verbundforschung, 31.08.2011 16 Project timeline 2008 10/2010 2011 2015 2016 2017 Application first Approval CDR TDR recirculation Project start detailed time planning detailed costing hiring additional personnel (~11FTE) started 7/2011 A. Jankowiak, Workshop Verbundforschung, 31.08.2011 17