ICFA mini-Workshop on Beam Commissioning for High Intensity Accelerators CSNS site, June 8, 2015 Synchrotron Overview Tadashi Koseki J-PARC center, KEK&JAEA Accelerator Laboratory, KEK
Contents 1. High power proton synchrotrons 2. High luminosity colliders 2. Challenges for high power accelerator operation 2. Acknowledgements
High power proton synchrotrons
Hadron accelerators in the world 1 MW Jie Wei / Y. Yamazaki
High power proton synchrotrons/rings operating as a front-runner Spallation Neutron Source, ORNL J-PARC, KEK&JAEA 3-GeV RCS, 1 MW / 30-GeV MR , 750 kW 1-GeV AR, 1.4 MW ISIS, STFC Main Injector, FNAL 800-MeV RCS, 200 kW 120-GeV Synchrotron, 700 kW
SNS Accelerator Complex Accumulator Ring Collimators 1 GeV Accumulator Ring: Front-End: Extraction Compress 1 msec long LINAC Injection Produce a 1-msec pulse to 700 nsec long, chopped, RF H - beam 1000 MeV RTBT 2.5 MeV HEBT Liquid Hg Front-End Front-End LINAC LINAC Target Chopper system makes gaps 945 ns mini-pulse Current Current 1 ms macropulse 1ms Courtesy of M. Plum
SNS beam power vs time Target issues 1.4 MW 1.0 MW - Demonstrated full design beam power for >24 hours for neutron scattering experiments, at the end of a run cycle, in June 2014. - At the beginning of the next run cycle, had a target failure, then other one in October 2014. - Operated at reduced power, about 850 kW, until they could get more spare targets. Restarted high power operations in April 2015. - Now operating at 1.1-1.3 MW, depending on warm linac cavity conditioning after an RF window replacement and/or condition of the ion source.
Challenge for target improvement • Target failures – 5 out of the last 11 targets have failed at weld joints – New designs to improve / eliminate weld joints 2014 Leak detector fluid “bubbling” through weld failure on the Target J-PARC had a trouble on a mercury target in the end of April 2015. Tiny water leak occurred at a weld joint on the target.
SNS future plans – 2 nd target station • Plan to add a second target station • Not funded yet, but project could start soon • Have baseline design, Technical Design Report • Working toward start of CD-1 preparations
Fermilab Accelerator Complex in PIP H - linac : accelerates H - to 400 MeV Booster : 4.2 × 10 12 protons, 400 MeV 8 GeV at 7.5 Hz, h=84 Recycler: a permanent magnet accumulator ring in the MI tunnel Main Injector: 8 GeV 120 GeV at 1.33 s cycle time, h=588 ( 7*84) 2+6 booster batches are injected to MI using slip-stacking Simultaneous operations of NOvA and SY120 (slow extraction beam) 0.5 sec. Revolution time of Recycler Courtesy of S. Nagaitsev
Beam power history for NuMI RR 2+6-batch Shutdown for the PIP; Recycler upgrade - installed Booster-to-RR and RR-to- MI transfer lines RR 6-batch - new rf system, transverse dampers MI only - instrumentation upgrades MI upgrade - 2 more cavities, - quad. power suppy.. Installation of 700 kW target /horns
On-going upgrade for 700 kW NOvA - Factor 2 increase in repetition rate ( 7.5 15 Hz ) of the booster by rf cavity refurbishment and tuner cooling upgrade - Loss reduction/mitigation in the Booster - 6+6 slip stacking in RR Testing 4+6 operation green line shows beam in the Recycler 700 kW by February 2016
PIP-II Goal: Provide >1 MW at the time of LBNF startup (~2023) 800 MeV superconducting pulsed linac + enhancements to existing complex Performance Parameter PIP-II Linac Beam Energy 800 MeV Linac Beam Current 2 mA Linac Beam Pulse Length 0.5 msec Linac Pulse Repetition Rate 20 Hz Linac Beam Power to Booster 13 kW Linac Beam Power Capability ~200 kW (@>10% Duty Factor) Mu2e Upgrade Potential >100 kW (800 MeV) 6.4 × 10 12 Booster Protons per Pulse Booster Pulse Repetition Rate 20 Hz Booster Beam Power @ 8 GeV 120 kW Beam Power to 8 GeV Program 80 kW (max) 7.5 × 10 13 Main Injector Protons per Pulse Main Injector Cycle Time @ 120 1.2 sec GeV LBNF Beam Power @ 120 GeV* 1.2 MW LBNF Upgrade Potential @ 60- >2 MW 120 GeV
PIP-III P I P - I I I “ m ul t i - M W ” - O pt i on C P I P - I I I “ m ul t i - M W ” - O pt i on A 120 GeV 120 GeV Main Injector Main Injector 8 GeV 8 GeV Recycler Recycler ? >2 MW >2-MW 8 GeV SRF Linac target target new 8-12 GeV =0.8 3 8 “smart” RCS -Booster i 800 MeV SRF Linac P I P - I I I “ m ul t i - M W ” - O pt i on B 120 GeV Main Injector 8 GeV Recycler >2 MW target New 8 GeV ~2=0.8+1.2 GeV RCS SRF Linac (or “greatly upgraded” Booster?) From “High Power Proton Beams for Particle Physics ” Sergei Nagaitsev, 11 th ICFA seminar on Futre Perspective in High Energy Physics
ISIS synchrotron Injection Energy 70 MeV Extraction Energy 800 MeV H - Charge Exchange Injection scheme Circumference 163.36 m Repetition 50 Hz Total beam power 0.2 MW The beam is split between TS-1 and TS-2, 40 pps to TS-1 and 10 pps to TS-2. Typical beam powers on each targets are 0.16 MW to TS-1; 0.032 MW to TS-2 Courtesy J. Thomason
Upgrade and future plans of ISIS TS-1 upgrade (~2019) - A newly optimized solid plate tungsten target, modulator and reflector are planned - Beam power is 0.16 MW as before, but expected to give at least 2 times larger neutron flux on every instrument Accelerator development and upgrade plans Upgrade of existing machine - Extensive studies of 180 MeV injection into the existing ring – would give 0.5 MW - Also smaller incremental steps possible ISIS II – Next Generation Short Pulse Source (new machine) - Study options e.g. 1-10 MW flexible, upgradable, multi-target facility Present ideas based on 5 MW RCS or FFAG (studies with ASTeC Intense Beams Group ) - 0.8-3.2 GeV RCS 0.8-3.2 GeV FFAG Courtesy J. Thomason
J-PARC Li nac RCS is proton driver for neutron/muon R C S production in MLF and booster for the MR. N eut ri no beam s t o S K M LF ( M at eri al and Li f e sci ence experi m ent al Faci l i t y) Ｍ Ｍ Ｒ Ｒ H adron experi m ent al hal l - 400-MeV H- linac - 3-GeV RCS with 25 Hz - 30-GeV MR with cycle time of 2.48/6.0 sec MR has a lattice of imaginary transition and two extraction modes.
Beam Power History at MLF • as of 3 rd of June 2015 593 kW 〜 560 kW 532 kW 500 kW Incident at Hadron Facility 400 kW 300 kW 300 kW Earthquake Hg-target replacement Interruption ～ 10 months interruption ～ 1 month interruption due a trouble due to the earthquake due to the fire in MLF of Hg-target
Demonstration of 1 MW-eq. beam 2015/1/10 BLM signals @ collimator & arc sections 8.41 x 10 13 :1010 kW-eq. Mainly from foil scattering during injection 7.86 x 10 13 :944 kW-eq. Number of particles / pulse (x10 13 ) 8.41 x 10 13 Collimator section 7.86 x 10 13 6.87 x 10 13 :825 kW-eq. 6.87 x 10 13 BLM signal (a.u.) 5.80 x 10 13 4.73 x 10 13 5.80 x 10 13 :696 kW-eq. First arc section (near the dispersion peak) 4.73 x 10 13 :568 kW-eq. Time (ms) Longitudinal beam loss Reinforcement of the anode power supplies of the rf power amplifiers is planned in 2015 summer shutdown periods. After the reinforcement, 1-MW user operation will start within this JFY. Time (ms)
History of MR beam power MR Beam Power 400 350 300 MR Beam Power (kW) 250 200 150 100 50 0 2010/01/01 2011/01/01 2012/01/01 2012/12/31 2014/01/01 2015/01/01 Date Delivered beam power is 360 kW for the T2K experiment. Total number is > 1.1x10 21 POT as of June 3.
Slow extraction operation in April, 2015 After the long shutdown for 1 year and 11 months due to the radioactive material leak incident, beam operation resumed for users in the hadron experimental facility.
Power upgrade plan of MR FX: The high rep. rate scheme is adopted to achieve the design beam intensity, 750 kW. Rep. rate will be increased from ~ 0.4 Hz to ~1 Hz by replacing magnet PS’s and RF cavities. SX: After replacement of stainless steel ducts to titanium ducts to reduce residual radiation dose, 50 kW operation for users will be started. Beam power will be gradually increased toward 100 kW carefully watching the residual activity. Local shields will also be installed if necessary. JFY 2014 2015 2016 2017 2018 2019 Li. current New power supply Event Buildings 30 -> 50 mA FX [kW] (study/trial) 240-320 >350 ~400 >400 ~750 >750 SX [kW] (study/trial) - 24~50 >50 50~100 ~100 100 2.48 s 1.3 s Period of magnet PS Mass production New magnet PS R&D Low cost R&D Present RF system Manufacture, installation & test High gradient rf system Add. colli. Add. colli. Back to Ring collimators JFY2012 (2kW) C,D E,F Kicker PS improvement, Septa manufacture /test Injection system FX system Kicker PS improvement, LF & HF septa manufacture /test SX collimator / Local Local shields shields Ti ducts and SX devices Beam ESS 2 with Ti chamber ducts 2
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