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PS2 Status. M. Benedikt for the PS2 working group. Main parameters. Goal: twice “ultimate” LHC & 20% reserve at PS2 injection. 1.7E11*2*1.2 = 4.0E11 per LHC bunch (25ns) Injection energy by incoherent SC considerations and scaling from PS (assuming “similar” bunches):
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PS2 Status M. Benedikt for the PS2 working group PAF meeting
Main parameters • Goal: twice “ultimate” LHC & 20% reserve at PS2 injection. • 1.7E11*2*1.2 = 4.0E11 per LHC bunch (25ns) • Injection energy by incoherent SC considerations and scaling from PS (assuming “similar” bunches): • bg2PS2 = bg2PS x (2 x 1.2) x (lengthPS2 / lengthPS) • Factor 5.15 increase for PS2 = 15/77 SPS 4.15 GeV instead of 1.38 GeV • Estimation of minimum length based on • 50 GeV extraction energy • 1.8 T maximum bending field • Result: minimum length of around 2*PS (see later) PAF meeting
RF considerations • Present PS performance depends critically on RF manipulations. RF requirements as basic input for lattice design: adiabaticity + voltage dependency on gamma_T. • Analysis of different RF scenarios for PS2 • PS2 RF similar to PS (10 MHz (400 kV), 20, 40, 80 MHz systems for LHC) • RF gymnastics at low and high energy • Ideal gamma_T around 6i to 10i. • Compatible with PS as injector and ion operation (not studied in detail) • PS2 RF with SPL as injection (40 MHz, system only, ~1.5 MV) • Injection of any bunch pattern up to 40 MHz with SPL chopping. • No gymnastics at low energy, bunch shortening (adiabatic or non ad.) at high energy • Gamma_T in the range 6 to 10 (real or imaginary) • 40 MHz has (very) limited tuning range non-compatible with ions? • Impact of RF on machine length: RF cogging with SPS PS2 = 15/77 SPS • For SPS FT filling with 5-turn MTE: only 2/77 SPS unfilled i.e. 0.6 micros. PAF meeting
Lattice considerations (i) • Based on RF requirements and general parameters. • Analysis of different cells for arcs (FODO, Doublet, Triplet and FMC) PAF meeting
Lattice considerations (ii) • FODO lattice with gamma_T = 9 for more detailed investigations • Regular structure with “missing-dipole” D-suppressors • Next steps: • Arc short straight section layout (correctors, pick-ups, multipoles) • CO, Q’ correction studies • Injection / extraction study • Gamma-T jump considerations • Site study with TS on implementation and geometry • FMC structure (with imaginary gamma_T) not yet chosen • Most probably DOFO type similar to JPARC design. PAF meeting
Injection / Extraction • Generic study of injection and extraction in PS2 • Assumption: racetrack machine with long SS parallel to TT10 • Injection from TT10 (or new injection line) • Extraction towards SPS point 1 • Injection requirements • H- at ~ 4 GeV with ~ 100 turns (500 micros) • Fast bunch-to-bucket injection from PS, RCS or LEIR (ions directly) • Extraction requirements • Fast towards SPS for LHC type beams • Five turn continuous (MTE) towards SPS for fixed target physics. • Slow extraction and fast extraction for PS2 physics • Single extraction channel for all extractions • Presently study of transfer line towards SPS (for FODO PS2) and separation for PS2 exp. areas. PAF meeting
Comparison of NC / SF or SC variants • First analysis to be finished by end of April • Identification of SIGNIFICANT differences between NC and SF variants in capital cost of main systems and in operation cost (energy and power consumption). • From machine operation requirements (apertures, working range, cycles) and preliminary 2-dimensional designs of the main magnets, the main parameters of magnet, cryogenic, cooling and power converter systems will be derived as basis for cost estimates. • Magnets, power converter, cryogenics done, CV and TS missing • Not included in present analysis: • Quench limit estimate (protons, ions) and impact on machine design. • Cost for machine protection and quench protection systems • Recovery time after a magnet quench • Cooling-down and warming-up time for SF machine and influence on shutdown/short stops. • Time to open the cryogenic system to install/remove equipment (magnet replacement time) • Safety aspects in accelerator tunnel • Operational flexibility / limitations • Tuning flexibility / limitations PAF meeting
Considerations on experimental areas • Sub-group with support from POFPA, physics coordinator, ATB/EA • High intensity experiments • E.g. Kaon physics, slow-extraction continuous operation • Target development, etc., fast extraction, single pulses • Requires dedicated area with adequate shielding (underground) • Low-Intensity test beams (similar to PS EAST Hall) • Irradiations, etc. • Presently ongoing • Generic layout of multi-usage caverns (halls) for high intensity experiments and also low-intensity area • Study with TS of implementation and cost (under ground, surface, etc.) PAF meeting