 Storage Ring RF system Progress Report
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Last Update : October 2005
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Storage ring main parameters
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| Circumference | 354 m | | Revolution frequency | 0.85 MHz | | Energy | 2.75 GeV | | Energy loss / turn | 1.15 MeV | | Beam current | 500 mA | | Momentum compaction
| 4.4 E-4
| | Momentum spred
| 0.35 % | | RF acceptance
| ± 6.15 %
| | Bunch length
| 4.2 mm | | RF frequency | 352.2 MHz | | RF voltage
| 4.8 MV | | Beam power
| 575 kW |
RF SYSTEM
| -> 4 superconducting cavities (inside 2 cryomodules)
Vcav = 1.2 MV; Pcav= 145 kW
-> 4 solid state amplifiers: 4 x 190 kW |
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Soleil Cryomodule design
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Soleil Cryomodule #1: Brief History
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1996, APD -> development of a prototype (CEA/CERN collaboration)
End of 1999, first tests (without beam) at CERN
2001, SOLEIL approval -> performance validation in ESRF storage ring
End of 2001, installation in the ESRF ring
2002, tests of the prototype in the ESRF e- beam, using LHe from Dewar
-> 1.5 MV/cav, 190 kW/coup @ 200 mA (OK for phase 1 of SOLEIL).  | | At the end of 2002, it was decided that : - The prototype became SOLEIL cryomodule #1
- Modifications before on-site installation (HOM & power couplers, thermal screen, internal cryogenic distribution, instrumentation)
- Order of the 2nd cryomodule (CM2 ≈ CM1) in the industry
| | | | | 2003-2004, disassembling, modifications & re-assembling of CM1 at CERN
2004-2005, cryogenic & RF power tests of CM1 at CERN | | | |  |  | | 2002 - Cryomodule prototype in the ESRF storage ring | End of 2003 - At CERN, waiting for access into the clean room | | |  |  | | February 2004 - Inside the CERN clean room: Removing of the power couplers |
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Measured Q0 versus Eacc
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| |  |  | | | For each cavity , Qo is larger than the specified value of
2 109 at Eacc of 6 MV/m |
 |  |  |  | | September 2004 at CERN: Re-assembling | | | |  |  | | September 2004 at the CEA: Mounting of the Cu (LN2-cooled) thermal screen into the cryomodule | | | |  |  | | December 2004 - Installation into the CERN bunker for cryogenic and RF power tests |
- LHe supplied from a CERN 18 kW liquefier through a buffer Dewar
- RF power from a LEP type klystron
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Successful results of the cryogenic and RF power tests at CERN
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- Tests in 2 steps: December 2004, without the T-type HOM couplers (not yet available); they were implemented in January 2005 and the tests completed in February 2005
- Each IPC was conditioned up to 200 kW CW with full reflection and Vcav>2.5 MV achieved in each cavity (SOLEIL normal operation: Pcoupler ~150 kW and Vcav ~ 1.5 MV)
- Lengthening of the IPC antennas -> Qext = (1±0.1)105, as expected
- Cooling improvements (cryogenic circuits, thermal shield + thermalisation straps,...)
-> 1/2 cryogenic losses
-> He collector 50% filled -> He is liquid at the inlet of the HOM couplers - After a proper redesign of the single wave bellow of the T-HOM couplers, their filter proved to be easily tunable -> rejection of 34 dB instead of 19 dB.
- Check of the tuning system functionality with the standard SOLEIL driving unit.
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Cryomodules status & schedule
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- Le cryomodule #1 est stocké au CERN, prêt pour utilisation -> Installation sur site prévue fin 2005.
- Le cryomodule #2 a été commandé à ACCEL en août 2005 -> Mise en place dans l'anneau de stockage prévue en mai 2007.
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The Cryogenic Source (LHe at 4.5 K)
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HELIAL 2000 liquefier (from Air Liquide) specified for 40l/h of LHe and 350W at 4.5K Its delivery is completed and its installation is going on -> commissioning before the end of 2005
| |  | | |  |  |  | | Cryogenic valve box | Room temperature valve panel | | |  | | RF cryogenics area | | |  | | RF cryogenics compressor room |
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Storage Ring 352 MHZ power source
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Storage Ring 190 kW amplifier
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| |  | Same principle as for the booster one, extended to 4 x 50 kW
(-> 724 modules of which 42 in "stand-by"), but other type of transistors | | |  | | Storage Ring amplifier - power combination scheme | | |  |  | | Power combiners for the storage ring amplifier | Power dividers for the storage ring amplifiers | | |  | | |
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Storage Ring LDMOS amplifier: History & test results
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- Booster: Only one transitor supplier, SEMELAB (VDMOS - D1029UK05)
- Storage Ring:SOLEIL-POLYFET development of LDMOS (several iterations)
-> LR301-V3: successful tests on a few samples - Contract with BBEF for 3000 modules with validation on a pre-series of 10 pieces
- June 2004: A 2.5 kW unit, made of 8 pre-series modules, successfully run for about 4 weeks
-> Production of 180 modules for one "50 kW tower" (1/4 amplifier) - 23 December 2004: The first "tower" delivered 48 kW CW for about 2 hours
- February 2005: Long duration tests ->After about 1000 hours of operation, 14 over 180 modules had failures (high gate leakage current at one side of the push pull pair, which did not stop the amplifier that was still delivering its power
-> Fabrication by POLYFET of a new version (V4), designed to be tougher, at the expense of a gain reduction of about 1dB. - May-June 2005: A 2.5 kW unit (8 modules -V4) has run for about 1000 h without any trouble.
The tower with V4 transistors has been completed and tested up to 50 kW CW.
2 transistors failed in the first few hours and after 1000 hours of operation, occured a total of 5 failures.
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50 kW towers: Transistor failure rate
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Damaged transistors after ~1000 hours of operation
randomly distributed on the amplifier |  | 14 of V3 5 of V4 |
| |  | | "50 kW tower" under power test | | |  | | "50 kW tower" control display (transistor currents, Pi & Pr) |
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Storage ring Low Level RF Electronics
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SOLEIL RF System : Summary of status and objectives
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| Storage Ring RF System | - Cryomodule #1 tested beyond the required performance. The on-site installation is scheduled at the end of 2005
- Cryogenics: All the components are now available, the installation is on going and the tests are scheduled for the end of 2005
| - Amplifiers: - Four 50 kW-towers completed
- One tower per month (fixed by transistor
production rate) | -> Two 190 kW-amplifiers for cryomodule #1 operational by
March 2006 | | Storage Ring commissioning (April 2006) with cryomodule #1 -> Phase 1 (3 MV, 300 mA) | | | - Cryomodule #2 (built by ACCEL) & 2 other amplifiers -> Implementation by May 2007
Phase 2 (May 2007):Operation with 2 cryomodules (4.8 MV, 500 mA) | | Upgrading projects | - FPGA-based LLRF; Transverse multi-bunch feedback
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