nikolay solyakilc-gde, beijing, feb.4-8, 20071 fermilab 3 rd harmonic cryomodule status n.solyak, h....
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Nikolay Solyak ILC-GDE, Beijing, Feb.4-8, 2007 1
Fermilab 3rd 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 Solyak ILC-GDE, Beijing, Feb.4-8, 2007 2
3rd 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 Solyak ILC-GDE, Beijing, Feb.4-8, 2007 3
Single Cavity Construction
With Magnetic Shields and Bladetuner
Nikolay Solyak ILC-GDE, Beijing, Feb.4-8, 2007 4
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 2007.
• HGRP: The Helium Gas Return Pipe weldment has been ordered and is due into FNAL in mid-March 2007.
• 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 Solyak ILC-GDE, Beijing, Feb.4-8, 2007 5
Cryomodule Status (Cont.)
• Heat Shields: All heat shields have been ordered and will arrive in mid-March 2007.
• Cryostat: The cryostat will be arriving at FNAL in February 2007.
• 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 Solyak ILC-GDE, Beijing, Feb.4-8, 2007 6
Cavity String on HGRP
Nikolay Solyak ILC-GDE, Beijing, Feb.4-8, 2007 7
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 Solyak ILC-GDE, Beijing, Feb.4-8, 2007 8
Mock-Up cavity string with He supply interconnect bellows
END-1_ASSY END-2_ASSY
2.0” DIAM X 8.625” LONGSTEEL ROD INSERT
4 Complete Assemblies.Glass-filled urethane18.3 LBS (each Assembly)$13,400 TOTAL
Nikolay Solyak ILC-GDE, Beijing, Feb.4-8, 2007 9
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 Solyak ILC-GDE, Beijing, Feb.4-8, 2007 10
3.9 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 (MPoverheatingfracture)
Nikolay Solyak ILC-GDE, Beijing, Feb.4-8, 2007 11
MP in notch gap 0.6 mm
3D simulation
Omega 3P(Analyst)
Enhanced counter function
1.E-05
1.E-03
1.E-01
1.E+01
1.E+03
1.E+05
1.E+07
0 5 10 15 20
Eacc (MV/m)
MP in 2 mm Leg-wall gap
Zoom
3.E+09
4.E+09
4.E+09
5.E+09
5.E+09
6.E+09
6.E+09
0.0 0.5 1.0 1.5 2.0
Eacc, MV/m
Q
0,E+00
1,E+09
2,E+09
3,E+09
4,E+09
5,E+09
6,E+09
0 2 4 6 8 10 12 14 16
Eacc, MV/mQ
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 Solyak ILC-GDE, Beijing, Feb.4-8, 2007 12
Secondary Emission Yield
This curve was used in simulation
Nikolay Solyak ILC-GDE, Beijing, Feb.4-8, 2007 13
MP in HOM coupler. Cavity No.2
Q vs. Hpeak for “0”-modeQ vs. E for -mode
MP in vertical test
Field for 0 and pi mode
Nikolay Solyak ILC-GDE, Beijing, Feb.4-8, 2007 14
Cavity No.3: Results of the Cold Test #3 (2007.01.17)
10
100
1000
10000
2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
Tc/T
nO
hm
s
RSBCS
QvsT at Pi-mode. F=3899.46 MHz. Cavity baked 150C 48 h. Rres=25 nOhms.
0.E+00
1.E+09
2.E+09
3.E+09
4.E+09
5.E+09
6.E+09
0 2 4 6 8 10 12 14 16
Eacc, MV/m
Q
QvsE, 2007.01.17.
At Eacc=12 MV/m quench in the bottom HOM.
0.E+00
1.E+09
2.E+09
3.E+09
4.E+09
5.E+09
6.E+09
7.E+09
0 20 40 60 80 100 120 140
Hsurf, mT
Q
Pi/9
2Pi/9
3Pi/9
4Pi/9
8Pi/9
Pi
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 Solyak ILC-GDE, Beijing, Feb.4-8, 2007 15
Experimental data for TESLA Z94 cavity
Z94_02_Aug24_06
1.0E+10
1.2E+10
1.4E+10
1.6E+10
1.8E+10
2.0E+10
0 5 10 15 20 25 30
* Actual notch gap in HOM coupler may not be 1.73mm as designed
Eacc, MV/m
Q0
MP in the gapEacc_sim ~1.5 MV/m
Nikolay Solyak ILC-GDE, Beijing, Feb.4-8, 2007 16
Modified 2-post design #2
F2=4190 MHz
F2=4350 MHz
1-post design #3
F2=4400 MHz
1-post design #4
1-post Long design #5
F2=2900 MHz
Few new Designs of the HOM coupler
-140
-120
-100
-80
-60
-40
-20
0
2500 3000 3500 4000 4500
Old 2 legsNew 2 legs1 leg, long1 dog leg1 leg, short
F2=4080 MHz
F2=4280 MHz
Trimmed Initial design -1a
Initial design No.1
Hp/H#1 Ep/E#1
HOM #1 1 1
HOM #1a 0.4 0.4
HOM #2 0.76 0.45
HOM #3 0.77 0.48HOM #4 0.67 0.31
HOM #5 0.57 0.098
cavity 7.4 3.5
HOM Comparison
Nikolay Solyak ILC-GDE, Beijing, Feb.4-8, 2007 17
HOM Damping properties for modified coupler design.
1.E+03
1.E+04
1.E+05
1.E+06
1.E+07
4800 4900 5000 5100 5200 5300 5400 5500 5600
F, MHz
R/Q
*Q
Before trimming
After trimming
HOM damping for the 1st Dipole band remains same and slightly worth for a 2nd dipole band.
HOM Damping for old HOM design(dark-blue)
and design with trimmed antenna(magenda)
Q_ext<105
Nikolay Solyak ILC-GDE, Beijing, Feb.4-8, 2007 18
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 0.62.5mm and formteil thickness 46mm.
• 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 Solyak ILC-GDE, Beijing, Feb.4-8, 2007 19
Main Coupler Status•Six input couplers (+1 spare) were received
from the vendor in June 2006. 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 Qext
•High power RF cycling to condition
Nikolay Solyak ILC-GDE, Beijing, Feb.4-8, 2007 20
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 2007. 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 Solyak ILC-GDE, Beijing, Feb.4-8, 2007 21
Main coupler test: First resultDrive Power v.s. Output Powers (with 3dB attenuator installed)
0
10
20
30
40
50
60
70
0 0.2 0.4 0.6 0.8 1 1.2Drive Power (W)
Ou
tpu
t P
ow
ers
(k
W)
Klystron F.P.
Load F.P.
Transmitted Power
Nikolay Solyak ILC-GDE, Beijing, Feb.4-8, 2007 22
3898.9
3899.0
3899.1
3899.2
3899.3
3899.4
3899.5
3899.6
3899.7
3899.8
-250 -200 -150 -100 -50 0 50 100 150 200 250 300
Position, microns
F "
Pi"
, M
Hz
Fpi vs Length2.1 MHz/mm
Room temperature tests
Blade tuner tests.
3751.6
3751.7
3751.8
3751.9
3752
3752.1
3752.2
3752.3
3752.4
-2 0 2 4 6 8 10 12
Test at 4K
2MHz/mm
Noise due to He pressure fluctuations.
~20um / turn
A0 Tests in liquid 4K He
Turns
Nikolay Solyak ILC-GDE, Beijing, Feb.4-8, 2007 23
Transition, S21
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
2 3 4 5 6 7 8 9 10 11 12
F, MHz
S21
4.0x0.8x0.8
4.0x0.8x1.04.0x1.0x0.8
4.0x1.0x1.0
HOM coupler feed through (Fermilab design).1st design manufactured in Ceramtec.
2nd design with sapphire.
Better thermal properties
Nikolay Solyak ILC-GDE, Beijing, Feb.4-8, 2007 24
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.13-14.
Nikolay Solyak ILC-GDE, Beijing, Feb.4-8, 2007 25
Q vs. Freq. for dipole modes (HH & EE boundaries)
1.E+02
1.E+03
1.E+04
1.E+05
1.E+06
1.E+07
4000 4500 5000 5500 6000 6500 7000 7500 8000 8500 9000 9500
MHz
Q
1.E+02
1.E+03
1.E+04
1.E+05
1.E+06
1.E+07
4000 4500 5000 5500 6000 6500 7000 7500 8000 8500 9000 9500
EE
HH
Q, current design. All dipole modes
Q, new design, 2 legs.Modes with high R/Q
Nikolay Solyak ILC-GDE, Beijing, Feb.4-8, 2007 26
P1, HOM1
P2, HOM2
P3, Coupler
EE
HH
S-parameters for current and new 2-leg designs
Current HOM
New design