3.9 GHz Cryomodule Shipment to DESY E.Harms on behalf of the Third Harmonic Effort Team (AD & TD, with help from PPD, FESS, BS)

What is the 3.9 GHz Effort? Fermilab has constructed a third harmonic accelerating (3.9GHz) Superconducting cavity and cryostat for a new generation high brightness photo-injector. This system will compensate the nonlinear distortion of the longitudinal phase space due to the RF curvature of the 1.3 GHz TESLA cavities prior to bunch compression. The cryomodule, with four 3.9GHz cavities, will be installed in DESY’s TTF/FLASH photoinjector downstream of the first eight cavity, 1.3 GHz cryomodule. Four 3.9 GHz cavities will provide the energy modulation, ~20 MV, needed for compensation. Part of Technical agreement with DESY as part of Tesla Technology Collaboration

General Parameters The Third harmonic system (3.9GHz) is proposed to compensate the nonlinear distortion of the longitudinal phase space due to cosine-like voltage curvature of 1.3 GHz cavities. It will linearize the energy distribution upstream of the bunch compressor thus allowing allowing the achievement of extremely small normalized emittance ~ m*rad (few time less than without). Parameter List for ACC39 V 3 =V 1 / 9 Number of Cavities4 Active Length0.346 meter Gradient14 MV/m Phase-179º R/Q [=U 2 /(wW)]750 Ω E peak /E acc 2.26 B peak (E acc = 14 MV/m) 68 mT Q ext 1.3 X 10 6 BBU Limit for HOM, Q<1 X 10 5 Total Energy20 MeV Beam Current9 mA Forward Power, per cavity 9 kW Coupler Power, per coupler 45 kW

Example: bunch phase space before and after bunch compressor without (left) and with (right) the 3 rd harmonic cavity, calculated for TTF-2 photoinjector. What is the 3.9 GHz Effort?

Cold Mass Assembly Three phases of Cold Mass Assembly –MP-9 string mated to 2-phase piping then to support structure –Transport to ICB Validate final design for over-the road transport Tie up traffic on Road D at noon on a Friday –ICB Encase string assembly in thermal shield Insert assembly into vacuum vessel Complete piping & instrumentation installation and checkout Final alignment Verify all systems

Transport to DESY Three hops from Fermilab to DESY –Truck to O’Hare Crated, security clearance, mounted on air pallet –Air Cargo to CDG, Paris Unexpected stop in Glasgow Download shock log data upon arrival Check state of cavity vacuum Monitor loading onto truck –Truck to Hamburg Shadowed transport truck Vacuum monitoring at stops Delivery to Hall 1 Monitor off-loading and oversee un-crating –Excellent coordination and communication Several coordination meetings Shipping rep at every transfer point Truckers very cooperative Plan ahead, lots of details!

Current Status and Short-term Fermilab staff present in Europe last week –Witness arrival at Paris, CDG and verify vacuum –Accompany truck to Hamburg –Un-crating, visual inspection, download stored shocklog and vacuum data Vacuum remained 7 E-4 Torr during transport Shock-logs record <1g on vessel Vessel is now open and being prepped for pump-down and vacuum leak check with portable clean room Three Fermilab staff arrive this week for –Cavity string alignment check –Warm-end input coupler installation (clean room work) Two more later in May –Instrumentation verification –Initial RF checks Wait for CMTB availability Isolation frame Base frame

Summary Fermilab has successfully delivered a 3.9 GHz Superconducting cavity RF module for TTF/FLASH at DESY: Effort largely complete, but not quite –Documentation –Final assembly and checkout –Warm & Cold power testing at CMTB - November –Installation in FLASH - December 2009 –Commissioning with beam - March 2010 International recognition that Fermilab has a unique capability in this area of Superconducting RF. Applications to: –Fermilab 1.3 GHz efforts for ILC and Project X, NML –European XFEL and other FEL’s –Deflecting ‘crab’ cavities for LHC, ILC, etc. Involvement of many people in AD and TD with support from other parts of Fermilab and great assistance from DESY colleagues.