Rejuvenation of 7-GeV SuperKEKB Injector Linac · ipac18-furukawa-poster.pptx (読み取り専用)...
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IrCe cathode KEK injector linac has delivered electrons and positrons for particle physics and photon science experiments for more than 30 years. It is being upgraded for the SuperKEKB project, which aims at a 40-fold increase in luminosity over the previous project KEKB, in order to increase our understanding of flavor physics beyond the standard model of elementary particle physics. SuperKEKB energy-asymmetric electron and positron collider with its extremely high luminosity requires a high current, low emittance and low energy spread injection beam from the injector. The electron beams will be generated by a new type of RF gun, that provides a much higher beam current to correspond to a large stored beam current and a short lifetime in the ring. The positron source is another major challenge that enhances the positron bunch intensity from 1 to 4 nC by increasing the positron capture efficiency, and the positron beam emittance is reduced from 2000 μm to 10 μm in the vertical plane by introducing a damping ring, followed by the bunch compressor and energy compressor. The summary of the rejuvenation is reported. High-current Low-emittance RF Gun e – / e + Injector rejuvenation with high-intensity and low-emittance beams towards 40-times higher luminosity, operating for Phase-II commissioning Rejuvenation of 7-GeV SuperKEKB Injector Linac Y. Enomoto, K. Furukawa, M. Akemoto, D. Arakawa, Y. Arakida, H. Ego, A. Enomoto, T. Higo, H. Honma, N. Iida, M. Ikeda, H. Kaji, K. Kakihara, T. Kamitani, H. Katagiri, M. Kawamura, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Miura, F. Miyahara, H. Nakajima, K. Nakao, T. Natsui, M. Nishida, Y. Ogawa, Y. Ohnishi, S. Ohsawa, F. Qiu, I. Satake, M. Satoh, Y. Seimiya, A. Shirakawa, H. Sugimura, T. Suwada, T. Takenaka, M. Tanaka, N. Toge, Y. Yano, K. Yokoyama, M. Yoshida, R. Zhang, X. Zhou High Energy Accelerator Research Organization (KEK), SOKENDAI, Tsukuba, Ibaraki, 305-0801, Japan Thermionic gun Primary RF gun Secondary RF gun Injector Linac Balanced Schedule for Improvements / Stability e – e – PF-AR 6.5 GeV PF 2.5 GeV Belle II HER 7 GeV LER 4 GeV e – BT e + BT SuperKEKB 3 km Damping Ring Low emittance RF-gun High efficiency e+ generator Injector Linac 600 m e + 40x Luminosity 2x beam current Beam from Injector and Storage Current SuperKEKB: 7 GeV e- 2600 mA 4 GeV e+ 3600 mA PF: 2.5 GeV e- 450 mA PF-AR: 6.5 GeV e- 60 mA RF-Gun e- beam commissioning at A,B-sector e- commiss. at A,B,R,C,1 e+ commiss. at 1,2 sector (FC, DCS, Qe- 50%) e- commiss. at 1,2,3,4,5 sector non damped e+ commiss. at 1,2, 3,4,5 sectors e- commiss. at A→5 sectors damped e+ commiss. at 1→5 Qe+ = 1~4nC e- commiss. at A→5 Qe- = 1~4nC : Electron : Positron : Low current electron 1 - 2 nC Phase2 1 nC Phase1 Location ↓ Time → Phase1: high emittance beam for vacuum scrub Phase2,3: low emittance beam for collision Without Top-up 2 - 4 nC Phase3 Improved RF gun Direct PF-AR BT DR Commiss. Beam Licenses in steps Low Emittance Beams 4+1 Ring Injections Low Emittance Injections Positron generator and its shield SuperKEKB Electron/Positron Complex PF / PF-AR photon science ◆Short-term in many groups ◆Stability intensive (Hates failures) ◆Deliberate scheduled maintenance ◆Invests on maintenance ◆Distance from users ◆Fixed procedures Difficult to train operators SuperKEKB particle physics ◆Long-term and fixed users ◆Performance intensive (Integrated performance) ◆Minimum preventive maintenance ◆Invests on improvements ◆May share common goal with users ◆Everyday is new On-the-job training for operators Typical Accelerator Units Pulse-to-pulse modulation operation Flux Concentrator e+ 4 nC Injection e- 10 nC Primary e- Bridge Coils beam hole Pulsed Corrector Magnets DC Focusing Magnets Pulsed Focusing Magnets Side view Solenoid LAS Accel. Structure Spoiler Target Virtual accelerators for simultaneous top-up injections Each VA with associated beam feedback loops Newly developed 64 pulsed magnets Synchronized Global Controls High-performance Pulsed Magnets Summary ◆Injector linac has been rejuvenated since 2010, and is close to its completion. ◆It successfully injected required electrons and positrons in SuperKEKB phase 1 & 2 commissioning. ◆It maintained light source injections during rejuvenation. ◆It is expected to improve for Phase 3 commissioning. Pulsed positron generator QTWSC cavity QTWSC cavity ARC e – (2.5GeV, 0.2nC) e− Gun ARC e+ Target e + (4GeV, 4nC) e− Gun PF Injection SuperKEKB-LER Injection e– (3.5GeV, 10nC) ARC e – (7GeV, 5nC) e− Gun SuperKEKB-HER Injection ARC e – (6.5GeV, 0.2nC) e− Gun PF-AR Injection Damping ring Event-based Control System Every 20 ms F.B F.B F.B F.B F.B F.B F.B F.B High-current Positron Generator Rejuvenated Injector Linac
Transcript of Rejuvenation of 7-GeV SuperKEKB Injector Linac · ipac18-furukawa-poster.pptx (読み取り専用)...
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IrCe cathode
KEK injector linac has delivered electrons and positrons for particle physics and photon science experiments for more than 30 years. It is being upgraded for the SuperKEKB project, which aims at a 40-fold increase in luminosity over the previous project KEKB, in order to increase our understanding of flavor physics beyond the standard model of elementary particle physics. SuperKEKB energy-asymmetric electron and positron collider with its extremely high luminosity requires a high current, low emittance and low energy spread injection beam from the injector. The
electron beams will be generated by a new type of RF gun, that provides a much higher beam current to correspond to a large stored beam current and a short lifetime in the ring. The positron source is another major challenge that enhances the positron bunch intensity from 1 to 4 nC by increasing the positron capture efficiency, and the positron beam emittance is reduced from 2000 µm to 10 µm in the vertical plane by introducing a damping ring, followed by the bunch compressor and energy compressor. The summary of the rejuvenation is reported.
High-current Low-emittance RF Gun
e– / e+ Injector rejuvenation with high-intensity and low-emittance beams towards 40-times higher luminosity, operating for Phase-II commissioning
Rejuvenation of 7-GeV SuperKEKB Injector Linac
Y. Enomoto, K. Furukawa, M. Akemoto, D. Arakawa, Y. Arakida, H. Ego, A. Enomoto, T. Higo, H. Honma, N. Iida, M. Ikeda, H. Kaji, K. Kakihara, T. Kamitani, H. Katagiri, M. Kawamura, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita,
S. Michizono, K. Mikawa, T. Miura, F. Miyahara, H. Nakajima, K. Nakao, T. Natsui, M. Nishida, Y. Ogawa, Y. Ohnishi, S. Ohsawa, F. Qiu, I. Satake, M. Satoh, Y. Seimiya, A. Shirakawa, H. Sugimura, T. Suwada, T. Takenaka, M. Tanaka,
N. Toge, Y. Yano, K. Yokoyama, M. Yoshida, R. Zhang, X. Zhou High Energy Accelerator Research Organization (KEK), SOKENDAI, Tsukuba, Ibaraki, 305-0801, Japan
Thermionic gun
Primary RF gun
Secondary RF gun
Injector Linac
Balanced Schedule for Improvements / Stability
e –
e –
PF-AR6.5 GeV
PF2.5 GeV
Belle II
HER7 GeV
LER4 GeV
e – BT
e+ BT
SuperKEKB3 km
DampingRingLow emittanceRF-gun
High efficiencye+ generator
Injector Linac600 m e+
40x Luminosity
2x beam current
Beam from Injector and Storage CurrentSuperKEKB: 7 GeV e- 2600 mA
4 GeV e+ 3600 mAPF: 2.5 GeV e- 450 mAPF-AR: 6.5 GeV e- 60 mA
RF-Gun e- beamcommissioningat A,B-sector
e- commiss.at A,B,R,C,1
e+ commiss.at 1,2 sector (FC, DCS, Qe- 50%)e- commiss.at 1,2,3,4,5 sector
non damped e+ commiss.at 1,2, 3,4,5 sectorse- commiss. at A→5 sectors
damped e+ commiss.at 1→5 Qe+ = 1~4nCe- commiss.at A→5 Qe- = 1~4nC
: Electron: Positron: Low current electron
1 - 2 nCPhase2
1 nCPhase1
Location↓
Time →
Phase1: high emittance beam for vacuum scrubPhase2,3: low emittance beam for collision
Without Top-up
2 - 4 nCPhase3
Improved RF gun
Direct PF-AR BT
DR Commiss.
Beam Licensesin steps
Low Emittance
Beams
4+1 RingInjections
Low Emittance Injections
Positron generator and its shield
SuperKEKB Electron/Positron Complex
PF / PF-AR photon science
◆ Short-term in many groups◆ Stability intensive
(Hates failures)◆ Deliberate scheduled maintenance◆ Invests on maintenance◆ Distance from users◆ Fixed procedures
Difficult to train operators
SuperKEKB particle physics
◆ Long-term and fixed users◆ Performance intensive
(Integrated performance)◆ Minimum preventive maintenance◆ Invests on improvements◆ May share common goal with users◆ Everyday is new
On-the-job training for operators
Typical Accelerator Units
Pulse-to-pulse modulation operation
Flux Concentrator
e+4 nC Injection e-
10 nCPrimary e-
Bridge Coils
beamhole
Pulsed Corrector Magnets
DCFocusingMagnets
PulsedFocusingMagnets Side view
Solenoid
LAS Accel. StructureSpoilerTarget
Virtual accelerators for simultaneous top-up injections Each VA with associated beam feedback loops
Newly developed 64 pulsed magnets
Synchronized Global Controls
High-performance Pulsed Magnets
Summary ◆ Injector linac has been rejuvenated
since 2010, and is close to its completion.◆ It successfully injected required
electrons and positrons in SuperKEKB phase 1 & 2 commissioning. ◆ It maintained light source injections
during rejuvenation.◆ It is expected to improve for Phase 3
commissioning.
Pulsed positron generator
QTWSC cavity
QTWSC cavity
ARC
e– (2.5GeV, 0.2nC)
e− Gun
ARC
e+ Target e+ (4GeV, 4nC)
e− Gun
PF Injection
SuperKEKB-LER Injection e– (3.5GeV, 10nC)
ARC
e– (7GeV, 5nC)
e− Gun
SuperKEKB-HER Injection
ARC
e– (6.5GeV, 0.2nC)
e− Gun
PF-AR Injection
Damping ring
Event-based Control System
Every 20 ms
F.B
F.B
F.B
F.B
F.B
F.B
F.B
F.B
High-current Positron Generator
Rejuvenated Injector Linac
