微波功率源组度工作总结

1、微波功率源组度工作总结微波功率源组度工作总结2The Committee suggests paying particular attention to the following details in 3rdIMAC and our responsesIn order to obtain the specified 2degrees RF phase stability, a temperature stabilized reference drive line needs to be established with a temperature coefficient of 0.1 deg

2、ree per C. The reference lines temperature coefficient is 5ppm/C, and will be stabilized with cooling water within 0.2C.Measuring and adjusting the RF phase with respect to the beam is not planned, but appears to be desirable. Based on some experiences, the beam induced signals are not so clear and

3、so stable, hence the energy maximum method is adopt to set the right RF phase. The Committee encourages the LINAC team to exercise the transport of the full energy beam into the injection channel as early as possible to preserve some flexibility within the tight schedule in case of unforeseen proble

4、ms. Yes, this will be done soon.微波功率源组度工作总结3The Committee would like to encourage the BEPC-II team to try to accommodate the full sub-harmonic bunching systems program or at least keep it as a high priority valuable upgrade option. The potential benefit may not only be the slightly increased injecti

5、on efficiency but these systems may also contribute significantly to providing tolerable condition for the colliding beam detector during top-up operation. It is planning to apply the budget, and may finish the technical design by full 2005, construction in 2006, be measured and RF conditioned in th

6、e 1st half 2007 and will be installed in the tunnel in summer 2007.With regard to operations, the Committee would like to mention that a single spare klystron might not be sufficient to provide the high machine availability necessary for the anticipated top-up mode. The Committee suggests to re-asse

7、ss the probability for system failures based on BEPC-I linac and SLAC linac operations. It is planed to make each 45-50 MW klystron be operated at 35-40 MW output, then two spare klystron may be possible; as a back-up version, one more SLAC-65 MW klystron may be prepared to instead of one 45-50 MW k

8、lystron and keep the total 16 klystron constant.微波功率源组度工作总结4Contents1. Sub-systems upgrade progress2. Machine commissioning3. Problems微波功率源组度工作总结51.1 Pre-injector 1. New electron gun (done)2. Bunching, RF system 1. Sub-systems upgrade progress微波功率源组度工作总结6200Kv High voltage station LINACElectron gunN

9、ew electron gun微波功率源组度工作总结7微波功率源组度工作总结8Gun controller & power supplyGunGun HV Modulator微波功率源组度工作总结9Design MeasureFrequency2856MHz 2856MHz Waveguide power divider1）VSWR 1.052）Imbalance 0.2dB3）Directivity 26dB1）VSWR 1.0382）Imbalance 0.05dB3）Directivity 29dB VSWR 1.2 1.2 Attenuation 0 25 dB 0 35 dB Pha

10、se shift0 360 0 360 Mid-power attenuator / phase-shifter used for pre-buncher Bunching, RF system微波功率源组度工作总结10Design MeasureFrequency2856MHz Waveguide power divider1）VSWR 1.052）Imbalance 0.2dB3）Directivity 26dBVSWR 1.2 Attenuation 0 25 dB Phase shift0 360 High-power attenuator / phase-shifter for bu

11、ncher微波功率源组度工作总结11微波功率源组度工作总结12Status and plans of SHB system1) Physical design has been made and reviewed by BEPCII organization.2) The technical design is on going, including the cavities, RF power supplies and so on. It will be reviewed in July 2006.3) A SHB2 prototype cavity has been made and co

12、ld tested.4) It is expected to be ready for installation of the SHB system by fall 2007.微波功率源组度工作总结13Beam Dynamics Simulation:Bunch length and emittance simulations from the gun to the buncher exit微波功率源组度工作总结14Structure of SHB2 test cavity微波功率源组度工作总结15微波功率源组度工作总结16微波功率源组度工作总结17 DC solenoide+ target

13、(Flux)1.2 New Positron Source (done)微波功率源组度工作总结18Measured Main Parameters（2004-2005）Design Measurede- Beam spot radius（mm）2.51.0 1.5e- Beam energy (MeV)240210 Flux pulse magnetic field（T） 12 kA pulse current4.5 0.5 5.3 0.5 Flux pulse magnetic field（T） operation current 10.2 kA 4.5 0.48 Solenoid magn

14、etic field （T） 350 A driving current 0.5 T 7 m0.5 T 7 mSolenoid magnetic field （T） operation current 320 A 0.48 T 7 me+ current solenoid exit (mA)88100e+ energy solenoid exit (MeV)80 - 100100e+ yield solenoid exit（e- /e+(GeV)4.3 7.6微波功率源组度工作总结19Upgrades of all 16 units have been completed.1.3 RF pow

15、er source (done)微波功率源组度工作总结2050KV / 30KW charging power supply微波功率源组度工作总结21Beam voltage / Beam current / RF output微波功率源组度工作总结22Improved Beam Voltage Flatness with New PFN InductorNew PFN Inductor Old PFN Inductor 0.37% 1%微波功率源组度工作总结23Beam Voltage StabilityTDS3034 with GBIP-USB-H + PC , Bandwidth: 20

16、MHz, 16 pulse average 7#10#0.175% 0.165 %0.13 % 0.115 %Without De-QingWith De-Qing0.175% 0.165 %0.13 % 0.115 %微波功率源组度工作总结241.4 RF Phasing SystemUnder testing微波功率源组度工作总结25Prototype Test Result at K9 Without phasing feedback with phasing feedback in 6 hours phase shift 100 0 微波功率源组度工作总结26Phase referen

17、ce systemPhase refer. lineCooling water systemT 0.1 Thermal chamber微波功率源组度工作总结27Phase and amplitude detectorFront panel of PADInside the PAD微波功率源组度工作总结28Mechanical phase shifter driven by stepping motor (IPA unit)Minimum insertion loss2.0dBMaximum insertion loss30dBMaximum phase shift500oMinimum pha

18、se shift step 500Repetition rate (Hz)5025-50Emittance (1) ( mmm rad )e+0.53 0.32 0.20e-0.067 0.080 0.096Energy spread (%)e+ 0.500.(0.)e- 0.50 0. (0.) Summary of the Linac commissioning (April-06) Red color: last run result 微波功率源组度工作总结64e+ beam emittance at 1.89 GeV (April 15, 2006)Beam current40 mAG

19、oal(mm-mrad)Measured(mm-mrad)Emittance- X (1)0.530.320.04Emittance- Y (1)0.530.240.05微波功率源组度工作总结65e- beam emittance at 1.89 GeV (April 16, 2006)Beam current500 mAGoal(mm-mrad)Measured(mm-mrad)Emittance- X (1)0.0670.0800.010Emittance- Y (1)0.0670.0960.017微波功率源组度工作总结663. ProblemsKlystron windows broke

20、n caused by the attachmentsThe gradients of the unit No.5 RF structures, presumably No.16 as well were degraded caused by arcing 微波功率源组度工作总结67Klystron windows broken caused by the attachmentsJuly 6,2005, we routinely shut down the machine for maintenance and for further upgrades, but found windows o

21、f No. 5, No.7 and No.11 klystrons broken; No.3, No.4, No.6 and No.9 small leaked!We soon started co-investigation with Toshiba and KEK experts, and found that No.11 window was dirty, but not too bad, No.7 and No.5 were badly contaminated with (C, Al) and (C, Cu, stainless steel) respectively.We repl

22、aced these three tubes, and took many measures to protect this kind of things happen again.微波功率源组度工作总结68微波功率源组度工作总结69微波功率源组度工作总结70微波功率源组度工作总结71Renew the vacuum system 60 old ion pumps (70 l/s) and power supplies have been replaced by the new or repaired ones, due to the aging problem (more than 20 y

23、ears) . 22 old vacuum gauges have been replaced by new ones (Belzers), more reliable and precise, more safe interlock. 30 l/s ion pumps is added at each klystron power output. The Klystron and valve vacuum interlocks are improved.微波功率源组度工作总结72微波功率源组度工作总结7330L/s ion pump150L/s ion pump70dB pumping wa

24、veguide微波功率源组度工作总结74The gradients of unit No.5 RF structures, presumably No.16 as well were degraded caused by arcing Without beam, we took almost a month to process No.5 klystron to 33MW, very hard.With beam, the output power gradually back to a very low level. Through hard processing, it can stay at 10MW, but once the arcing happens, out-gassing is terrible.We are going to further investigate, and replace the 4 RF structures in due time.微波功率源组度工作总结75Schematic of No.5 accelera