KEK Participation in the LHC Injector Upgrades C. Ohmori, KEK/J-PARC M. Paoluzzi, CERN 10 PSB cavitiesPS Damper cavities

Magnetic Alloy-FINEMET ® loaded wideband cavities for CERN PSB and PS in the frame of the LHC Injector UpgradeCollaborative Work ICA/JP/0103 RF Collaboration for LHC Injector Upgrade Objectives Consolidation/upgrade of the PSB RF systems possibly using wideband, multi-harmonic, solid-state driven Magnetic Ally loaded cavities Development and installation of a longitudinal damper in the PS Core Technology : Wideband Cavity using Magnetic Alloy,Finemet-FT3L Use of Solid State Amplifiers Collaboration activities Studies on the PSB multi-gap wideband cavity-beam interactions – Beam Studies at J-PARC MR during LS1 & PSB Study radiation damage on solid-state RF amplifier – Radiation damage test at J-PARC MR Study, design and prototype a longitudinal damper for the CERN PS – Wideband cavity system to damp the longitudinal coupled bunch instability Collaboration on the conceptual design of feed-forward beam compensation schemes for FINEMET ® cavities – J-PARC wideband cavities handles 1E14 ppp in MR with Feed Forward compensation in LS1 Committee2

Advantages of Magnetic Alloy (Finemet®) Cavity for J-PARC Case RF cavity loaded with magnetic alloy cores High field gradient -> Compact accelerator for 3 GeV RCS New Cavity for High Rep. Rate of MR (2.48 sec-> faster than 1.3sec cycle !) Wideband system -> dual harmonic acceleration for J-PARC RCS Stable operation of high intensity beams cavities of proton rings New FT3L cavity In J-PARC MR （ installed in 2014 ） 32 kV/m at test bench （ New Record! ） 4 more cavities Installs in summer Committee3

Committee4 Status of J-PARC accelerator 530 kW eq. /4 pulses > sec rep. Linac delivers 50 mA ! RCS accelerates 1 MW eq. Max beam current/power from latest beam test Linac beam current J-PARC center meeting 2015/7/ 400 MeV Linac 3 GeV RCS 30 GeV MR No. of proton per pulse 1 pulse injection (4 is normal) 132 kW by 1 batch If 4 batch, 530 kW

Advantages of Magnetic Alloy (Finemet®) Cavity for PSB/PS Case Committee5 RF cavity loaded with magnetic alloy cores High field gradient -> Replacement of PSB cavities Enough voltage to damp coupled bunch instability at PS Wideband system -> dual harmonic acceleration for PSB compensation of multi-harmonics for PS Stable/medium impedance Compact RF system driven by solid state amplifiers Multi-cell structure (24-36 cell / PSB ring, 24 is enough) Reduction of down time Cost reduction: no bias PS, no tube, no anode PS

Objectives Consolidation/upgrade of the PSB RF systems possibly using wideband, multi-harmonic, solid-state driven RF cavities Development and installation of a longitudinal damper in the PS Core Technology : Wideband Cavity using Magnetic Alloy,Finemet-FT3L Use of Solid State Amplifiers Collaboration activities Studies on the PSB multi-gap wideband cavity-beam interactions – Beam Studies at J-PARC MR during LS1 & PSB Study radiation damage on solid-state RF amplifier – Radiation damage test at J-PARC MR Study, design and prototype a longitudinal damper for the CERN PS – Wideband cavity system to damp the longitudinal coupled bunch instability Collaboration on the conceptual design of feed-forward beam compensation schemes for FINEMET ® cavities – J-PARC wideband cavities handles 1E14 ppp in MR with Feed Forward compensation in LS1 Committee6 FINEMET ® loaded wideband cavities for CERN PSB and PS in the frame of the LHC Injector UpgradeCollaborative Work ICA/JP/0103 RF Collaboration for LHC Injector Upgrade

Magnetic Alloy- Finemet® Committee7 MA Cavity: V=Z(f) x I RF Ferrite cavity: V=Z(f, ferrite bias, temperature, B RF,) x I RF Characteristics Cavity Impedance Shunt impedance RF voltage

Committee8 Finemet cavities may (will) work as C02 & C04 systems M. Finemet review

Mass Production of Magnetic Alloy- Finemet® Committee9 KEK-system Company KEK-made cores will reduce temperature of cavity core. KEK-made Magnetic annealing oven for Mass Production worked very well. 280 large cores were produced in 1.5 yr. Mass production for J- PARC MR is over. Overhaul of oven is also finished in March. Availability and reliability of cores look OK. Improvement of Finemet® Core will be a important contribution from Japan. Magnetic annealing oven for nano-crystallization

Solid State Amplifiers Radiation Damage – Tests at J-PARC & Fraunhofer – Choice of FET – Compensation of radiation Reliability – Many minor modifications (cooling units, connectors,,) – Documentations for PS/PSB Availability – Production in Europe/Japan Committee10 J-PAC tunnel: charged particles, n,  similar to PSB/PS FY15, KEK will make 2 units for PS Damper based on CERN-documents. J-PARC Compensation of radiation PSB RF section: Gy/yr

Japanese contributions (Solid State AMP) Supply of Solid State Amplifiers for PSB two rings is included in ATLAS-Japan proposal for LHC/ATLAS upgrade. – KEK-CERN has an experience of collaboration on solid state amplifier for J-PARC in Production Plan The schedule fits the request for LIU. Precise cost estimation is under taking. 44 sets of solid state amplifiers for two PSB rings will be covered by this proposal. Committee # amp Cost6M JPY 48M JPY 24M JPY 150 AMPs for J-PARC w/o problem (PS)(R&D) Quantity can be delayed SSA for PSB

Objectives Consolidation/upgrade of the PSB RF systems possibly using wideband, multi-harmonic, solid-state driven RF cavities Development and installation of a longitudinal damper in the PS Core Technology : Wideband Cavity using Magnetic Alloy,Finemet-FT3L Use of Solid State Amplifiers Collaboration activities Studies on the PSB multi-gap wideband cavity-beam interactions – Beam Studies at J-PARC MR during LS1 & PSB Study radiation damage on solid-state RF amplifier – Radiation damage test at J-PARC MR & detail design on cooling Study, design and prototype a longitudinal damper for the CERN PS – Wideband cavity system to damp the longitudinal coupled bunch instability Collaboration on the conceptual design of feed-forward beam compensation schemes for FINEMET ® cavities – J-PARC wideband cavities handles 1E14 ppp in MR with Feed Forward compensation in LS1 Committee12 FINEMET ® loaded wideband cavities for CERN PSB and PS in the frame of the LHC Injector UpgradeCollaborative Work ICA/JP/0103 RF Collaboration for LHC Injector Upgrade feedback

Beam Test at J-PARC MR during LS1 Committee13 1.4x10 13 protons were handled by a single AMP system ! SSA technology & damper cavity are useful for other rings: J-PARC, RHIC

Recent Beam Acceleration at PSB Beam test up to ppp Using for CERN (~86%) user operation as H=2 cavity Promising results for high intensity operation. Committee14

Committee15 L. Ventura, Finemet Review 2014

Study, design and prototype a longitudinal damper for the CERN PS Instability is excited after passing γT and after bunch splitting at flat top. Combination of wideband cavity & solid state amplifier is installed. Technology developed for PSB is applicable for this purpose. Emittance growth by Longitudinal Coupled Bunch Instability. Frequencies to be damped: many harmonics of revolution frequency, not only RF frequency => Wideband damper ! Beam test using ferrite cavity (narrow band) Committee16 H. Damerau

Committee17 First Finemet Review: Sep nd Review: Sep to advise -> Next year

Committee

Other topics Other applications at CERN – ELENA anti-proton deceleration cavity – Replacement of AD CO2 RF System – Inductive adder with Finemet® Technology Future application for J-PARC – Feedback SSA for MW beam Technology transfer for Medical accelerators – MedAustron, KHIMA in Korea Universal cavity system ! Committee19

Summary CERN-KEK Synergy for low frequency RF technology has been continued for over 10yr. – This technology will be used for other machines; ELENA, AD, J- PARC, RHIC, medical machine,,, Participation for LIU was successful. – Upgrade of PSB RF system – PS damper system KEK will support the mass production of FT3L Finemet® cores. Contribution for PSB SSA production is under consideration. – In FY15, Production of 2 SSA for PS Damper. SSA technology might be employed J-PARC MR feedback AMP for MW beam. Committee20 In this collaboration, experiences are circulating!

Committee21 Thank you! First Magnetic Alloy from 2005 Nice View in Bldg.150

Back up slides Committee22

PS Longitudinal Damper Frequency : MHz. Peak voltage : up to 5 kV. 6-cells cavities. Each cell with one gap and 2 Finemet® cores. Each cell driven by two 2.5 kW solid-state amplifier. Water cooled cavities and amplifiers. During 2012, with CNGS high intensity operation, the dose measured was ~1.6 kGy. => AMP Needs more protections

Other contributions (better FT3L cores) Pop FT3L production test by KEK – KEK system has better performance Production of FT3L cores using KEK- made mass production system may help to improve the PSB cavity performance. KEK system was shipped to company Committee ton rental magnet Shunt impedance (  ) J-PARC-system Company Will reduce temperature of cavity core.

H. Damerau, Chamonix 2012, 09/02/2012 Timeline (present baseline) New coupled- bunch feedback PS PSB-PS transfer 1.4 GeV  2 GeV PSB H - injection ready for installation Chamonix 2012 Linac4 deliver- ing H - into PSB if connected in LS2 LS1 for injectors LS2 for injectors 1.4 GeV  2GeV 2 GeV upgrade of PSB + increase of PS injection energy excluded for LS1 LS1.5? Linac4 ready, p+ from Linac PSB RF system Damper system

Studies on the PSB wideband cavity-beam interactions Reducing ferrite cavity voltage, tried to accelerate 4.6E12 PPP using 5-gap FT3L cavity, as # of FT3L cavity is not enough. Achieved ~ 60% of typical maximum LHC: few 1E12 ppb, 130 ns High Intensity Goal : 1.4E13 ppb, 200 ns full use of the Linac4: 2.5E13 ppb Mauro Paoluzzi Ferrite cavity voltage FT3L cavity voltage Beam current Beam Phase ↑ Injection ↑ Extraction Beam acceleration test at PSB Beam Test at J-PARC MR Collaboration on the conceptual design of feed-forward beam compensation schemes for FINEMET ® cavities A single gap cavity was shipped from CERN and installed. The test will be done next March. Test Committee26 After LS1, number of FT3L cavity is increased and acceleration only using FT3L cavity will be tried.

Ferrite and FT3L cavities FerriteFT3L MaterialFerriteMagnetic alloy- ribbon Typical Q-value~100~1 BandwidthNarrowWide Cavity acceleration NecessaryNot necessary  Qf Stability NoYes Field few MHz <15 kV/m~30 kV/m for J-PARC upgrade Dual HarmonicNo (need another cav.) Yes FT3L is two times higher than FT3M FT3L Flux density in material ∝ V Product of  Q f ∝ -1 Loss FT3M FT3M cavities in Low Energy Ion Ring by CERN-KEK collaboration(~’05) Committee27 In PSB and PS,  is not about 1. The accelerating frequency has to be changed according to energy. Traditionally, ferrite-loaded cavity was used to change it. ferrites

Committee28

Ferrite-loaded cavities & vacuum tube amplifiers Present PSB RF system C02 : freq= MHz C04 : freq MHz FT3L cavities & solid state amplifiers Wideband systems Committee29 Many RF stations => Failure of one (a few) RF systems does not affect the operation. Consolidation/upgrade of the PSB RF systems Advantages: high voltage, modular system, spare system, more spaces, simple Risk: New technology and configuration. => need study before replacements

PIN Diode neutron FET low-sens. dose RadMon Single Ev. FET high-sens. dose FETs to be tested RadMon RadMon Moj. FET to test Study of radiation damage on solid-state RF amplifier High Power FETs from different suppliers were tested using a collimator section of J-PARC MR. The dose was monitored by CERN-made “RadMon” system. Two FETs （ MRFE6 、 SD2942) look possible to use. They are stronger than FET (MRF151G) currently used in PSB tube amp. According to dose, characteristics changes ! RadMon Collimator Section The results are consistent with the experience that MRF151G survives in PSB ( RF sections: 14, 30,1 Gy ) Committee30 Core technology

Committee31

補償あり 補償なし Beam Signal Wake Voltage Committee32 きれいに消えた 実際にはセルンの特異なフィードバックでの補償を予定