CANADA’S NATIONAL LABORATORY FOR PARTICLE AND NUCLEAR PHYSICS Owned and operated as a joint venture by a consortium of Canadian universities via a contribution through the National Research Council Canada Electron Linac Photo-Fission Driver for the Rare Isotope Beams at TRIUMF S. Koscielniak, F. Ames, R. Baartman, P. Bricault, I. Bylinskii, Y.-C. Chao, K. Fong, R. Laxdal, M. Marchetto, L. Merminga, A. Mitra, I. Sekachev, V. Verzilov, V. Zgavintsev SRF 2009 Workshop, Berlin, 25 Sept 2009 LABORATOIRE NATIONAL CANADIEN POUR LA RECHERCHE EN PHYSIQUE NUCLÉAIRE ET EN PHYSIQUE DES PARTICULES Propriété d’un consortium d’universités canadiennes, géré en co-entreprise à partir d’une contribution administrée par le Conseil national de recherches Canada Existing Facilities E-Linac Photo-Fission Driver for RIB at TRIUMF 2 10-year plan: ARIEL project – new isotope production facility for ISAC expansion Staged installation 5-Year Plan .New complementary driver (e-linac): electron driver for photo-fission .New target station and mass separator .New p-beam line 10-Year Plan .New front end and post accelerators .Additional target station .Three simultaneous radioactive beams E-Linac Photo-Fission Driver for RIB at TRIUMF 3 E-Linac Motivation/Impact .New Science: Nuclear physics with neutron-rich RIBs .High purity radioisotope beams .Complementary & independent RIB driver .Enhanced science output: multiple beams to multiple users .Steady RIB production: staggered E-Linac & cyclotron shutdowns .Leverages valuable existing infrastructure: .Proton Hall: available shielded vault with services .World-class RIB multiple experimental stations .Expands SCRF in-house expertise .Prepares Canada for SCRF projects world-wide (ILC, CERN-SPL) .Qualifies commercial partner (PAVAC) to build SCRF cavities .4th Generation Light Source Testbed – CSS (x-ray), CSR (IR, THz) E-Linac Photo-Fission Driver for RIB at TRIUMF 4 What is photo fission? Electron γ-ray Radioactive ions beam photons Tungsten (Hg) Uranium oxide converter target production target Production efficiency: one γ-photon Photo-fission cross-section high for 15 for three electrons (30 MeV) MeV γ due to Giant Dipole Resonance E-Linac Photo-Fission Driver for RIB at TRIUMF 5 E-linac photofission neutron Photofission of 238U was Fission proposed by W. T. Diamond High energy fragments (Chalk River) in 1999 [NIM, V Photon 432] as an alternative neutron production method for RIB. Fission fragments neutron Electron- 238U Mass RIB E-linac Photon Ion Source Target Separator User Converter E-Linac Photo-Fission Driver for RIB at TRIUMF 6 E-Linac Specification Beam power (MW) 0.5 Duty Factor 100% Average current (mA) 10 Kinetic energy (MeV) 50 Photo-fission products distribution using 50 MeV 10 mA electrons on to Hg convertor & UCx target Number of photo-fission /second versus electron energy for 100 kW e-beam on Ta convertor and U target. E-Linac Photo-Fission Driver for RIB at TRIUMF 7 E-Linac Beam Specification Practical Bunch charge (pC) 16 considerations Bunch repetition rate (GHz) 0.65 (beam diagnostics) Radio frequency (GHz) 1.3 motivate bunch Average current (mA) 10 rep rate The requirement: Kinetic energy (MeV) 50 50 MeV × 10 mA = ½ MW beam Beam power (MW) 0.5 power eliminated Duty Factor 100% on target. Bunch vital statistics (rms) inject eject Normalized emittance (μm) <30π <100π Not critical; Longitudinal emittance (eV.ns) <20π <40π beam Bunch length (FW), inject (ps) <170 <30 dumped on target Energy spread (FW) <1 keV <1% E-Linac Photo-Fission Driver for RIB at TRIUMF 8 E-linac layout Thermionic gun: 100 keV; triode operation: 650 MHz Injector: Main linac: 10 Solenoids 10 MV/m, Q=10 Two cryomodules 10 mA, 5-10 MeV gain Two cavities/module, ≤ 100 kW beam power 10 MV/m, Q=1010 10 mA, 40 MeV gain ≤ 400 kW beam power NC Buncher SC Capture Cavities Solenoid 9-cell Cavities Division into injector & main linacs allows: .Possible expansion for: .Energy Recovery Linac (ERL) – e.g. 10 mA, 80 MeV .Recirculating Linear Accelerator (RLA) – e.g. 2 mA, 160 MeV E-Linac Photo-Fission Driver for RIB at TRIUMF 9 2008 Baseline E-linac for 2010-2015 2x5 kW 25 kW 50 kW 50 kW 50 kW 50 kW e-GUN BEAM TRANSPORT MAIN LINAC LINE BUNCHER INJECTOR MAIN LINAC CAVITY LINAC CRYOMODULE #1 CRYOMODULE #2 E-linac power distribution Final E-linac in 2015-2020 plan: 500 kW, 50 MeV 2x5 kW 50 kW 50 kW 50 kW 50 kW 50 kW 10 MeV 50 e-GUN MeV BEAM TRANSPORT MAIN LINAC LINE BUNCHER INJECTOR MAIN LINAC CAVITY LINAC CRYOMODULE #1 CRYOMODULE #2 50 kW 50 kW 50 kW 50 kW 50 kW E-Linac Photo-Fission Driver for RIB at TRIUMF 10 Beam Dynamics Studies for E-Linac Design Design Considerations • Input beam • RIB beam RIB 100 10 • Light-source beam 16 pC per bunch keV MeV • Beam property requirements N transverse (m) 7.5 12.5 • Optimized at 10 MeV & 50 MeV • 16 pC / 100 pC per bunch Bunch length (cm) 2.8 0.6 • Constraints Energy spread (keV) 1 40 • Physical dimensions • Diagnostics/control configurations • Hardware strength/power/hardware cost • Solution robustness • Sensitivity to input & hardware perturbations Light source 200 50 • Ability to recover from perturbations 100 pC per bunch keV MeV Tools Used • Simulation N transverse (m) 1.0 10.0 • 100 keV eGun: GPT, SimIon • Injector and Linac: Astra, Parmela, Track: Bunch length (mm) 4.0 1.0 • Genetic Optimization Energy spread (keV) 0.5 50 • APISA* and locally added features • Robustness Analysis Programs under Development E-Linac Photo-Fission Driver for RIB at TRIUMF 11 * I. Bazarov and C. Sinclair, PRST-AB 8, 034202 (2005), & ref. therein. • Multiple-objective optimization • Good convergence to solution set (Pareto front) • Solutions identified meet design requirements • Trade-off between objectives maps out feasible operation envelope and options. • Optimization provides unambiguous basis for • Selecting among different configuration choices Pareto Front of 3-objective optimization • Geometry EmitX • Hardware types 40 200 • Configuration layout 30 • Studying exception cases 150 • Robustness study to address MaxP 20 100 • Sensitivity to jitters 50 EmitZ95 • Design tolerance 20 30 40 10 • Ability to recover from errors 5 10 5 MaxZ EmitX 15 Performance comparison between normal and exception cases: red: =0.7+=1.0 capture Pareto fronts for 1.55 m (red) buncher-to- cavities, green: =0.7+=0.7, capture distance and 1.05 m distance (green) blue: 1st capture only (=0.7), pink: 2nd capture only (=1.0), E-Linac Photo-Fission Driver for RIB at TRIUMF olive: 2nd capture only (=0.7)12 . Beam dynamics: 100 keV - 50 MeV low charge (16pC) elinac for ARIEL 5.0 5.0 2.5 2.5 0. 0. -2.5 -2.5 xp vs. x yp vs. y -5.0-2.00 -1.00 0. 1.00 2.00 -5.0-2.00 -1.00 0. 1.00 2.00 element 23 Zpos= 1059.000 ngood= 10001 2.00 150 1.00 75 0. 0 rms normalized (cmmrad)normalized rmsemittance -1.00 -75 y vs. x e-es vs. phi-phis -2.00 -150 -2.00 -1.00 0. 1.00 2.00 -10.0es= 53.1447-5.0 ps=0. 113.195.0 z= 1059.010.0 Curves represent results of capture Beam portraits at the linac exit section optimization for Energy spread (3 rms): 0.32% combinations of single cells with Bunch length (3 rms): 6.4 ps different kinematic β E-Linac Photo-Fission Driver for RIB at TRIUMF 13 E-Linac funding status is complicated by multiple sources/agencies .Collaboration with Variable Energy Cyclotron Centre VECC (Kolkata, India) .Signed MOU in August 2008. Scope: build and beam- test Injector Cryo-Module (VECC ICM) at 10MeV/50kW .Collaboration with Canadian University Partners .U.Vic and TRIUMF submitted October 2008 proposal to Canada Foundation for Innovation (CFI) for full eLinac .July 2009 CFI awarded Ca$17.76 million to eLinac .BUT must obtain matching funds for civil construction from Province (B.C.) before federal money is released. E-Linac Photo-Fission Driver for RIB at TRIUMF 14 Schedule • October 2008 – Start Injector Beam Dynamics design • July 2009 – Single cell β=1 prototyping and test • December 2009 – VECC ICM technical design • November 2010 – Assemble ICM1 • May 2011 – Beam test with VECC ICM in ISAC-II – Build e-linac infrastructure in Proton Hall – Start assembly 2nd ICM for eLinac • December 2011 – Test ICM2 in Proton Hall • July 2013 – E-linac beam test • November 2013 – Ready for RIB production up to 100 kW • 2017 – E-linac beam test at full energy and full power E-Linac Photo-Fission Driver for RIB at TRIUMF 15 Electron Source Thermionic gun – inexpensive, simple, low maintenance NIST/JLab electron gun was donated to TRIUMF Being converted from diode to triode RF modulated gun avoids chopping and high power beam dump at linac start 3 2 1 0 W (keV) W RMS Ellipse -1 -2 -3 -30 -20 -10 0 10 20 30 (degree) Longitudinal emittance simulation (SIMION 3D ) at the gun exit Electron gun development stand E-Linac Photo-Fission Driver for RIB at TRIUMF 16 Use/adapt existing equipment designs wherever possible TTF 9-cell cavities – with modified end cells and large diameter beam pipe Cornell/CPI 50 kW c.w. power couplers XFEL industrialisation makes Saclay Type I tuner a strong candidate. E-Linac Photo-Fission Driver for RIB at TRIUMF 17 Cavity Development with PAVAC • PAVAC is a local company with EBW expertise – Now produces 20 QW 141MHz cavities for ISAC-II • PAVAC to produce two single cells in 2009 – Dies sourced from FNAL/RRCAT – Forming and welding tests underway (in copper and Nb) • PAVAC to produce multicell cavity prototype in 2010.