Proton Linac, Workshop, December 3 rd - 4 th, 2007 The FAIR Proton Linac Outline Requirements to Proton Linac Source, RFQ, DTL, RF Beam Dynamics Civil Construction

Proton Linac, Workshop, December 3 rd - 4 th, m FAIR: Facility for Antiproton and Ion Research 7  cooled pbar / hour

Proton Linac, Workshop, December 3 rd - 4 th, 2007 <=100 x : 4 x : Injection of protons into SIS18 Acceleration to 2 GeV Injection into SIS100 Acceleration to 29 GeV Impact on target  hot pbars Stoch. pbar cooling in CR Injection into in RESR Injection into HESR Acceleration to 14.5 GeV or Deceleration in NESR to 30 MeV Extraction to low energy pbar experiments Accelerator Chain for Cooled Antiprotons

Proton Linac, Workshop, December 3 rd - 4 th, 2007 η MTI → 60% (good empiric value) Injection into Synchrotron SIS18 The client of the p-linac is SIS18 Number of protons that can be put into SIS18 limited to, i.e. depends on energy Number of SIS18 turns during injection depends on phase space areas acceptance of SIS18 single shot from p-linac ( emittance ~ size 2 ~ γ -1 ) η MTI := green area / red area = filling factor SIS18 p-linac Injection energy → duration → current → emittance ε are coupled Energy remains to be chosen

Proton Linac, Workshop, December 3 rd - 4 th, 2007 Choice of Proton Linac Energy final rate of cooled pbar depends on injector energy: 70 MeV → 16.5 mA / µm → I = 35 mA βγ ε x = 2.1 µm limited by stoch. cooling power

Proton Linac, Workshop, December 3 rd - 4 th, 2007 p-Linac Overview ECR proton source & LEBT RFQ 2 re-bunchers 2*6 accelerating cavities 5 MW of beam loading (peak), 710 W (average) 11 MW of total rf-power (peak), 1600 W (average) 2 dipoles, 45 quadrupoles, 7 steerers 10 turbo pumps, 34 ion pumps, 9 sector valves 41 beam diagnostic devices Beam energy Beam current (op.) Beam current (des.) Beam pulse length Repetition rate Rf-frequency Tot. hor emit (norm.) Tot. mom. spread Linac length 70 MeV 35 mA 70 mA 36 µs 4 Hz MHz 2.1 / 4.2 µm ≤ ± ≈ 35 m Diagnostic insertion

Proton Linac, Workshop, December 3 rd - 4 th, 2007 Partners and People University of Frankfurt Cavity design RFQ design (4-rod) Beam dynamics CEA/Saclay Proton source & LEBT ITEP Moscow RFQ design (4-vane) GSI Darmstadt Cavity design, Beam dyanamics/diagnostics, Magnets, Power converters, Rf-sources, Proton source, Diagnostics, UHV, Civil constr., Controls, Coordination U.Ratzinger, A.Schempp, R.Tiede R.Gobin et al. G.Aberin-Wolters, R.Bär, W.Barth, G.Clemente, P.Forck, L.Groening, R.Hollinger, C.Mühle, H.Ramakers, H.Reich, W.Vinzenz, S.Yaramyshev S.Mineav et al.

Proton Linac, Workshop, December 3 rd - 4 th, 2007 Proton Source & LEBT Proton energy95 keV Proton current100 mA Max. rep. rate4 Hz β γ ε tot (transv.)≤ 1.8 µm High reliability High stability Requirements at LEBT exit: SILHI at CEA/Saclay: 95 keV, > 100 mA, dc 95 keV

Proton Linac, Workshop, December 3 rd - 4 th, 2007 Beam Measurements at CEA/Saclay Measured beam parameters meet..the requirements to FAIR p-linac Stable source needed for production..machine like p-linac LEBT exit: two measurements using different electronics, separated by 4 days, intermediate opening of the plasma chamber: optics for RFQ-injection During 3 weeks of measurements : always reliable & stable 100 mA beam no single sparking of the HV no interruption due to any malfunction

Proton Linac, Workshop, December 3 rd - 4 th, 2007 Radio Frequency Quadrupole (RFQ) 3.5 m 4-rod (cheaper)4-vane (state of the art) Two designs followed: Both designs meet requirements 0.1 MeV 3.0 MeV

Proton Linac, Workshop, December 3 rd - 4 th, 2007 Drift Tube Linac DTL 3.0 MeV 70 MeV DTL: wall plug power → em. (rf) fields (325 MHz) → proton beam power Creation of rf-power is project cost driver 64% of p-linac project cost related to rf-power

Proton Linac, Workshop, December 3 rd - 4 th, 2007 Rf-Power Source (Klystron) TOSHIBA Klystron 3740A/GSI peak rf-power 3.0 MW no R&D related cost & risks first device ordered delivery in March 2008 klystron: wall plug power → rf-field power industrial devices length ≈ 5 m weight ≈ 2.5 tons

Proton Linac, Workshop, December 3 rd - 4 th, 2007 rf-power → beam power Accelerating Cavities Crossed-bar H-Cavity (CH) New development for FAIR p-linac rf → beam power conversion efficiency CH conventional

Proton Linac, Workshop, December 3 rd - 4 th, 2007 Accelerating Cavities H – Field E – Field rf-coupling cell Rf-coupling of CH-cavities: reduce number of klystrons reduce place requirements profit from 3 MW klystron development avoid rf-power line splitting reduce cost for rf-equipment 3.0 MeV 70 MeV 1:2 Model

Proton Linac, Workshop, December 3 rd - 4 th, 2007 Rf-Power Requirements Rf-frequency Req. rf-peak power Power to Beam Power to Load Rf-pulse length Repetition rate MHz 2.5 MW 1.25 MW 70 µs 4 Hz per rf-load (incl. margin): 7 Klystrons 2 solid state amplifiers, IOTs,... 1 power converter / rf-source RFQ DTL Buncher Heat Beam

Proton Linac, Workshop, December 3 rd - 4 th, 2007 R&D: Testing of Klystron & CH-Cavity Operation Choice of Toshiba klystron & CH-cavities approved by ext. committees But: CH-cavities never built 3 MW klystrons never operated at GSI Rf-test stand mandatory for testing and staff training cavity klystron (protection) power supplies radiation shielding

Proton Linac, Workshop, December 3 rd - 4 th, 2007 Beam Dynamics Layout x / y [mm] final phase space distributions proton beam envelopes → full transmission OK still too high by 35% OK

Proton Linac, Workshop, December 3 rd - 4 th, 2007 Beam Dynamics, Losses due to Machine Errors, Hot Spots magnet alignment accelerating field voltage accelerating field phase

Proton Linac, Workshop, December 3 rd - 4 th, 2007 Civil Construction

Proton Linac, Workshop, December 3 rd - 4 th, 2007 Civil Construction 1800 m 2 of space required; 7700 m kW of peak power consumption 450 kW of water cooling 200 kW of air cooling Ground floor Second floor

Proton Linac, Workshop, December 3 rd - 4 th, 2007 Steps in near Future Construction of prototype CH-cavity just started; ends Q3/2009 Rf-test stand construction will start in 2008; ends Q1/2009 CH-cavity testing in 2009 / 2010