Electron linac photo-fission driver for rare isotope program at TRIUMF

Transcription

1 Canada s national laboratory for particle and nuclear physics Laboratoire national canadien pour la recherche en physique nucléaire et en physique des particules Electron linac photo-fission driver for rare isotope program at TRIUMF 2011 March 31 Shane Koscielniak & e-linac team Accelerating Science for Canada Un accélérateur de la démarche scientifique canadienne Owned and operated as a joint venture by a consortium of Canadian universities via a contribution through the National Research Council Canada Propriété d un consortium d universités canadiennes, géré en co-entreprise à partir d une contribution administrée par le Conseil national de recherches Canada

2 ARIEL Project 10-Year Plan: Motivation ISAC III New Mass Separators New Targets e-linac New Accelerators New Front End Cyclotron ISAC I ISAC II To substantially expand RIB program with: three simultaneous beams increased number of hours delivered per year new beam species increased beam development capabilities New complementary electron linac (e-linac) driver for photo-fission New proton beamline New target stations and front end Staged installation PAC'11 NYC NY. THOCN3 2

3 Photo-fission production of Rare Isotope Beams Photofission of 238 U was proposed by W. T. Diamond (Chalk River) in 1999 as an alternative production method for RIB. High energy Photon neutron Fission fragments neutron neutron Fission fragments E-linac Electron- Photon Converter 238 U Target Ion Source Mass Separator RIB User PAC'11 NYC NY. THOCN3 3

4 Why photo-fission, rather than proton driver? Smaller range & depth of products, with emphasis on neutron rich species. BUT lower isobaric contamination, lower activation, easier remote handling. Fission rate/e << rate/p. But easily compensated in source; 10 ma gun easy. β=v/c=1 from the start. Single RF structure throughout, lowers cost. PAC'11 NYC NY. THOCN3 4

5 E-Linac Physics Requirements Number of photo-fission/second vs electron energy for 100 kw e- beam on Ta convertor and U target. For in-target fissions up to /s Photo-fission products distribution using 50 MeV 10 ma electrons on Hg convertor & UC x target Beam power (MW) 0.5 Duty Factor 100% Average current (ma) 10 Kinetic energy (MeV) 50 PAC'11 NYC NY. THOCN3 5

6 ARIEL Funding July 2009 CFI awarded funds for e-linac- with release contingent upon matching funds for labour (NRC) and buildings (Province). April 2010, the NRC contribution to Five Year Plan became known: TRIUMF funded at level of M$222 over 5 years. June 2010 Province (B.C.) awarded funds for ARIEL building. Jan 2011 MoUs with CFI partner Universities complete 2010 June 22 nd : Red letter day PAC'11 NYC NY. THOCN3 6

7 Key Milestones: Injector Cryomodule test with beam: 2012 Nov Accelerator Cryomodule equipment test: 2014 June ACM test with 100kW electron beam: Jan 2015 PAC'11 NYC NY. THOCN3 7

8 300 kev Thermionic gun: triode operation at 650 MHz E-Linac: Accelerator Overview Injector: Q 10 MV/m, 10 ma, 5-10 MeV gain 100 kw beam power Power levels as in 2017 Main linac: Two cryomodules Two cavities/module, Q 10 MV/m, 10 ma, 40 MeV gain 400 kw beam power SC Solenoids Capture NC BuncherCavities cavity Solenoid Division into injector & main linacs allows: Possible expansion for: Energy Recovery (ERL) or Energy Doubler (RLA) Add return arcs to make a ring. 9-cell, RF Cavities PAC'11 NYC NY. THOCN3 8

9 Future (>2015) p-beamline 4) HPRF 3) Cryoplant 2) Cryomodules 1) Gun & LEBT Cyclotron Vault E-linac vault PAC'11 NYC NY. THOCN3 9

10 Former Proton Hall being cleaned out and refurbished as electron linac vault After Before PAC'11 NYC NY. THOCN3 10

11 ARIEL target Hall (2 targets) 80 metres long beamline Future (>2015) proton beamline Electron linac vault PAC'11 NYC NY. THOCN3 11

12 300 kev Thermionic Gun Specifications Beam energy Average current Modulation freq Bunch length (FW) Bunch charge Energy spread Emittance (1 σ) 300 kev 10 ma 650 MHz 16 deg 16 pc 1keV FW 5μm normalized e-gun on HV platform in N2/SF6 gas mix at 2 atm. TUP017: Conceptual Design of the Elinac 300 kev Gun Solenoid Ceramic Vacuum & Diagnostics Cathode Anode RF Gate Valve Steering Coil PAC'11 NYC NY. THOCN3 12

13 Main components of e-linac Injector Low Energy Beam Transport (ELBT) Injector cryomodule Buncher cavity E-gun Diagnostic line Solenoid magnets for focusing being re-designed. PAC'11 NYC NY. THOCN3 13

14 1.3 GHz NC Buncher matches beam to 9-cell cavity On site November 2009 Daresbury EMMA design purchased from Niowave Parameter value Frequency (GHz) Shunt resistance Realistic (80%) 4.3 (MΩ) 3.44 (MΩ) Q 0 23,000 R/Q 147 Tuning (MHz) -4 to +1.5 PAC'11 NYC NY. THOCN3 14

15 Injector Cryomodule, elevation m m VECC ICM design progressing: consistent with small static and large dynamic heat loads. Borrows many features from successful ISAC-II CMs Such as top-loading CM PAC'11 NYC NY. THOCN3 15

16 Injector Cryomodule, plan Single-cavity ICM prototypes most of the features of the two-cavity ACM design 3.5 metre Accelerator Cryomodule, plan PAC'11 NYC NY. THOCN3 16

17 Accelerator Cryomodule ISO View With Tank Side Removed ACM 27Deg. Tank Warm/cold Transition Ends Cold mass (cavity string and 2- phase helium pipe) supported from strong back Strong back held in place by support posts strung from the lid PAC'11 NYC NY. THOCN3 17

18 Final strong-back coldmass design Scissor-Tuner Cavity Tank Assembly TUP027: The SRF Program for e-linac at TRIUMF New Coupler Region Design PAC'11 NYC NY. THOCN3 18

19 Simplified block diagram for e-linac He Cryogenic System elinac Cryomodules Subatmospheric Pumping system Compressor He Dewar Purity monitoring (control) System OR/GMS, Dryer, Purifier Cold Box Clean Helium Storage Tank Dirty Helium Storage Tank Liquid 4K closed re-liquefaction/refrigeration loop Liquid 2K produced in cryomodules by subatmospheric pumping PAC'11 NYC NY. THOCN3 19

20 E-linac Cryogenic System Block Diagram Compressor Building MAIN Compr. He clean buffer tank recovery dumping cleaning He dirty buffer tank cooldown He Heat Exng Purifier Purif./ Recov. Compr. Sub-atm Pump cooldown He Heater Dewar Cryomodules Cold Box LN2 tank N2 Heat Exng PAC'11 NYC NY. THOCN3 20

21 Cryomodule Schematic Diagram 4K Supply Cooldown 77K Supply 4K Return 2K Return Heater Sub-atm pump 77K Exhaust Cooldown valves 4K Cool 4.2 K Phase separator Counter-flow He Subcooler J-T Valve 2K Supply Heat intercepts PAC'11 NYC NY. THOCN3 21

22 HPRF staging: 5mA, 25 MeV Date: keV e-gun 5mA, 5MeV 50 kw coupler * ACCELERATOR CRYOMODULE #1 50 kw Couplers 2 50 kw Cornell/CPI coupler per cavity 1.3GHz NC Buncher Cavity INJECTOR CROMODULE 50 kw coupler 30 kw IOT 50 kw coupler 250 kw Single 50 kw Modified TTF style cavity HOM damping for 1 st and 3 rd dipole pass bands TUP026: Cavity Design for the TRIUMF e-linac 250 kw Klystron PAC'11 NYC NY. THOCN3 22

23 HPRF staging: 10 ma, 50 MeV Date: kw IOT ACCELERATOR CRYOMODULE #1 ACCELERATOR CRYOMODULE #2 50 kw coupler * 50 kw Couplers 50 kw Couplers 300keV e-gun 1.3GHz NC Buncher Cavity INJECTOR CROMODULE 10mA, 5MeV 50 kw coupler 50 kw coupler 50 kw 50 kw coupler 50 kw 30 kw IOT 250kW Klystron 250 kw Klystron PAC'11 NYC NY. THOCN3 23

24 HPRF System Schematic ICM ACM 1 CAV 1 27 kw at the power coupler power coupler CAV 2 power coupler CAV 3 54 kw at the power coupler dbm directional couplers 2 m wave guide loss =0.02 db dbm 12 m wave guide loss =0.11 db 50 Ω two-stub phase shifter 50 Ω IL=0.05 db dbm 3 db hybrid IL=0.1 db dbm two-stub phase shifter 10 m wave guide loss =2.1%=0.09 db dbm variable attenuator IL=0.05 db dbm dbm IL=0.1 db 50 Ω IL=0.04 db dbm dbm IL=0.2 db 3 db hybrid IL=0.1 db dbm 50Ω load 50Ω load circulator 50Ω load IL=0.2 db dbm 250 kw for controlled operation dbm dbm RF DRIVE 30kW IOT 1 RF DRIVE 30kW IOT 2 RF DRIVE 300 kw saturated power Klystron 1 PAC'11 NYC NY. THOCN3 24

25 Candidate klystron: 1.3 GHz 300 kw at KEK Under tested at KEK since 2010 Sept. Amiya Mitra present for 1 st tests. Presently achieved 280 kw. PAC'11 NYC NY. THOCN3 25

26 Ground Breaking News, 2011 March 28 Relocation of Stores & RH make way for ARIEL PAC'11 NYC NY. THOCN3 26