Nikolay SolyakILC-GDE, Beijing, Feb.4-8, Fermilab 3 rd Harmonic Cryomodule Status N.Solyak, H. Edwards, D.Mitchell, M.Foley, T.Khabiboulline, E.Harms, A.Rowe, D.Olis, W-D.Mueller, T.Arkan, J.Reid,.. DESY personnel,

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, rd Harmonic Cryomodule Status Cavity design: Modified cavity HOM couplers; current direction is a one legged formteil (antenna/hook). New cavities are beginning to be fabricated. Helium vessel: A modification to the vessel has been designed and implemented to minimize the detuning of the cavity during the welding process. Three vessels are complete. Three are still at the vendor. Old vessel will be modified to use for welding test with cavity No.1. Bladetuner: We have procured 6 new stainless steel bladetuners and motors. Old bladetuner are tested at 4K. Main Couplers: 7 couplers are fabricated (6 +1 spare). Two outer conductors parts send to CPI for repair (copper plating problem). Two power couplers are being tested and conditioned.

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, Single Cavity Construction With Magnetic Shields and Bladetuner

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, Cryomodule Status (Cont.) Feedthrough for HOM couplers: 9 feedthroughs from one vendor are at FNAL, tested. The contract with this company has ceased. A new vendor is now supplying 3 new (with sapphire) prototypes. If successful, the remaining order will be placed. Field Probes: These probes need an antenna extension that will be fabricated at FNAL. Needle Bearings: Due in to FNAL in February HGRP: The Helium Gas Return Pipe weldment has been ordered and is due into FNAL in mid-March Magnetic Shields: Shields are procured and at FNAL. Helium Supply Pipes: All titanium pipes and bellows have arrived at FNAL and are in the QC process.

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, Cryomodule Status (Cont.) Heat Shields: All heat shields have been ordered and will arrive in mid-March Cryostat: The cryostat will be arriving at FNAL in February Invar rod & Clamps: At FNAL Cold Posts: INFN is shipping FNAL 2 cold posts. Support Posts: The steel support posts are completed and at FNAL. Post Covers: 2 post covers are at FNAL.

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, Cavity String on HGRP

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, Cryomodule Mockup Plan Mockup cavities are being produced to jump-start the cryomodule assembly process. We will learn how to assemble cavities, test our tooling, discover what is still missing, and will be able to test fit all of the parts, and document the build sequence. Mockup process begins mid-February ’07. The entire cryomodule will be constructed with 90% of the real components. Insulation and shield welding will not be used.

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, Mock-Up cavity string with He supply interconnect bellows END-1_ASSY END-2_ASSY 2.0” DIAM X 8.625” LONG STEEL ROD INSERT 4 Complete Assemblies. Glass-filled urethane 18.3 LBS (each Assembly) $13,400 TOTAL

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, Horizontal Test Stand Dressed cavity testing at 1.8 K Pulsed RF power from 80 kW 3.9 GHz klystron Measurements of X-rays, dark current, temperatures for diagnostics Facility commissioning (with 1.3 GHz TESLA cavity) during February/March

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, GHz 3rd Harmonic Cavity Production Status Four cavities completed - two at Fermilab, two at JLab Cavity No.4 with modified HOMs completed. Test at mid-Feb. Cavities 5-8 will be built with completely new design HOM’s for for Cavity 5-8 (+spares) are in hands Extra parts for cavities 9-10 No.5-6 –JLAB, March No. 7-8 FNAL May Problems with the HOM coupler in cavity No. 2 (MP  overheating  fracture)

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, MP in notch gap 0.6 mm 3D simulation Omega 3P(Analyst ) MP in 2 mm Leg-wall gap MP in old (first) HOM design Cavity No.3. Results of vertical test#2: MP observed at Eacc~0.7MV/m (Q drop). Quench at Eacc~14MV/m. Second resonance frequency of HOM was tuned higher than designed value.

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, Secondary Emission Yield This curve was used in simulation

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, MP in HOM coupler. Cavity No.2 Q vs. H peak for “0”-mode Q vs. E for  -mode MP in vertical test Field for 0 and pi mode

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, Cavity No.3: Results of the Cold Test #3 ( ) QvsT at Pi-mode. F= MHz. Cavity baked 150C 48 h. Rres=25 nOhms. At Eacc=12 MV/m quench in the bottom HOM. Q vs. max. surface H-field for some modes. Quench in HOM for Pi and 8/9Pi modes and in the cavity cells for lower modes. T-sensor between welds of the bottom HOM go up to maximum 6 K. RF fall time 20 msec. MP 12MV/m

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, Experimental data for TESLA Z94 cavity * Actual notch gap in HOM coupler may not be 1.73mm as designed Eacc, MV/m Q0 MP in the gap E acc _sim ~1.5 MV/m

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, Modified 2-post design #2 F 2 =4190 MHz F 2 =4350 MHz 1-post design #3 F 2 =4400 MHz 1-post design #4 1-post Long design #5 F 2 =2900 MHz Few new Designs of the HOM coupler F 2 =4080 MHz F 2 =4280 MHz Trimmed Initial design -1a Initial design No.1 Hp/H#1Ep/E#1 HOM #111 HOM #1a0.4 HOM # HOM # HOM # HOM # cavity HOM Comparison

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, HOM Damping properties for modified coupler design. HOM damping for the 1 st Dipole band remains same and slightly worth for a 2 nd dipole band. HOM Damping for old HOM design (dark-blue) and design with trimmed antenna (magenda) Q_ext<10 5

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, SUMMARY of HOM studies Old HOM coupler design shows strong MP at level Eacc=12 MV/m. Few new designs (one or two legs) were proposed to reduce MP, field level in coupler and improve thermal properties. In a new designs we have increased the notch gap 0.6  2.5mm and formteil thickness 4  6mm. Simulations shows, that new designs have good HOM damping and much less MP. 1-leg design #4 after testing of copper prototypes was approved for cavities No.5-8. All formteils are fabricated (+spares for 5 cavities) are fabricated. Old HOM couplers with trimmed (~3mm) antenna will test on Cavity No.4. Good chance of success.

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, Main Coupler Status Six input couplers (+1 spare) were received from the vendor in June Parts initially rejected for failing quality control checks have subsequently been replaced or reworked by the vendor and are currently undergoing QC. Input Coupler Qualification and Test Visual inspection (Cu plating, threaded holes, flange orientations, sealing surfaces, and overall workmanship) Mechanical measurements Leak check of all subassemblies Low power test Trimming couplers antennas to adjust Q ext High power RF cycling to condition

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, Input Coupler and Test Stand Status Two couplers were assembled onto the test stand in November 2006 and baked at 150C. Vacuum readings are 1x10-9mbar. Commissioning of the RF system was completed in mid- January Cautious ‘manual’ conditioning has begun. 1.3 ms pulses of 53 kW power at 0.33(?) Hz repetition rate (limited by klystron power) result in slight temperature increases in both ceramic windows. Field probes, vacuum gages, and PMT’s have not yet shown activity. 3.9 GHz 80kW Klystron Coupler Test Fixture Klystron’s Charging Supply & Modulator (left foreground – red cabinets)

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, Main coupler test: First result

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, Room temperature tests Blade tuner tests. Noise due to He pressure fluctuations. ~20um / turn A0 Tests in liquid 4K He Turns

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, HOM coupler feed through (Fermilab design). 1 st design manufactured in Ceramtec.2 nd design with sapphire. Better thermal properties

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, Summary  Cavity production delayed due to MP problem in HOM coupler. New formteis will be available for welding to a new end groups next week. Cavities No. 5-6 will complete in March, No. 7-8 in May ‘07  Five Main Couplers completed, Two parts under repair. Two couplers under test: 53kW, 0.1ms – no MP, sparks.  Major components of cryomodule are in hands. Mock-up assembly will begin in February ‘07.  Welding cavity to helium vessel will begin in mid-Feb  Plans and schedule under discussion with DESY.  Plan deliver CM with assembled cavity string inside  More details in DoE SRF Review, next week, Fermilab Feb

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, Q, current design. All dipole modes Q, new design, 2 legs. Modes with high R/Q

Nikolay SolyakILC-GDE, Beijing, Feb.4-8, P1, HOM1 P2, HOM2 P3, Coupler EE HH S-parameters for current and new 2-leg designs Current HOM New design