Beam Manufacture in PS2 M. Benedikt, S. Hancock

LHC Beams in the PS by 2015 Typeh injε l inj [evs] h ejN bunch ej RF ej [MHz] ε l ej [evs] τ ej [ns] LHC LHC Pilot TOTEM LHC ION nom160.05* *2084 ION early * *2084

Other Beams in the PS by 2015 Typeh injε l inj [evs] h ejN bunch ej RF ej [MHz] ε l ej [evs] τ ej [ns] SFT81.3(420) SFT_b EAST ?? AD ?? TOF ?? PS FT new SFTION

PS RF Systems Present PS: 5 distinct RF systems –10 MHz ( MHz) only tuneable system Acceleration Gymnastics –200 MHz fixed frequency Controlled blow-up SPS pre-bunching –13/20 MHz, 40 MHz, 80 MHz fixed-frequency systems for LHC-type beams Bunch train production Bunch shortening.

First Ideas for PS2 Minimize number of RF systems in PS2: –One accelerating system Revolution frequency ratio for protons in PS: 1,094 Revolution frequency ratio for protons in PS2: 1,024 Revolution frequency ratio for Pb54+ in PS&PS2 with injection directly from LEIR: 2,7 –System(s) for controlled blow-up and also for LHC bunch production and shortening

Injector SPL - Protons Beam characteristics SPL –~0,5 ms H - beam, 352 MHz, ~1.4E14 per pulse –Chopper designed for 40 MHz operation Accelerating RF system 40 MHz (tuneable?) –Paint directly any bunch pattern for LHC –FT beam for SPS with 40 MHz Debunched beam for new MTE? –Bunch-to-bucket transfer with empty buckets is not an issue for SPS space charge due to 50 GeV transfer energy instead of 13 GeV. For new PS beams –Any bunch pattern down to 25 ns spacing.

SPL parameters DesignSPL nominalSPL (5 GeV) Output energy [GeV] Beam power [MW]4 (5) Max. rep. rate [Hz]50 Protons p. pulse [10 14 ] Protons p. bunch [10 9 ]1.14 Av. pulse current [mA]40 Pulse length [ms] Rms bunch length at linac output [ps]12≈11 Chopping ratio [%]62 Chopping scheme (shortest possible)3 out of 8 Bunch frequency [MHz]352.2 Transv. norm. rms em. [mm mrad]0.4 Longitudinal rms emittance [deg MeV]0.2 Linac length [m]430535

Injector PS - Protons Is it possible to produce 40 MHz spacing via splitting at ~4 GeV before ejection to PS2? –At this energy we have gained more than a factor 4 in space charge tune spread. –Check if existing 40 MHz can be tuned down (permanently) to the required ~38 MHz?

IONS Beam directly from LEIR –Structure from LEIR to fit 40 MHz system (40/2.7=14.8 MHz at injection) –Tuneability of RF To be checked –Space charge issues –Beam size (aperture) –General issues (B at injection, ripple, etc.) Alternatives to handle ions? –Dedicated RF system for ions (FINEMET, ~MHz) –Lower frequency tuneable ferrite RF (10 MHz) for protons and ions –At least frequency ratio of 2 in main accelerating system to do rebucketing

Further Work Tuneability and gradient for ferrite systems as function of frequency Alternatives for ion acceleration (FFAG, Booster ring) Choices for high-frequency system(s) for blow-up and bunch shortening