ALBA RF Systems Francis Perez ALBA Accelerators LINAC
ALBA RF Systems Francis Perez
ALBA Accelerators LINAC 100 Mev BOOSTER 100 Me. V – 3 Ge. V STORAGE RING 3 Ge. V
LINAC RF System
Linac RF Thales Turn Key 100 Me. V • Electron Gun : Thermionic (Pierce type), 90 k. V DC gun with grid modulator at 500 MHz • Bunching Section: Pre-buncher: single cell @ 500 MHz Buncher: 1 SW bunching section @ 3 GHz Energy at the bunching section output = 16 Me. V • 2 Acc. sections: TW 2/3π Constant Gradient 3 GHz. Energy gain= 55 Me. V @ 20 MW nominal input power. • 2 Klystron modulators: 35 MW each klystron at 3 GHz. The first one feeds the 3 GHz bunching section and the 1 st acc. structure. The second one feeds the second accelerating structure
Linac RF Modulators: 270 k. V – 290 A Controls Vacuum PS Klystrons: 3 GHz - 35 MW - pulsed
Linac RF P [MW] E [Me. V] Buncher 5 (K 1) 15 Acc. section 1 20 (K 1) 55 Acc. section 2 20 (K 2) 55 EXIT 45 MW 125 Me. V
Booster RF System
Booster RF At 3 Ge. V: RF Voltage 1000 k. V Beam current 4 m. A Losses 627 ke. V/turn Beam power 2. 5 k. W Cavity power 34. 5 k. W TRANSMITTER Tube type IOT HVPS 36 k. V / 4 A RF Power 80 k. W Efficiency > 60%
Booster RF Cavity: 5 cell Petra type Basic Parameters Rshunt Maximum Power Length 15. 4 MW 75 k. W 1, 65 m
Storage Ring RF System
SR RF Power Requirements Beam current Bending losses 400 m. A 1000 ke. V/turn 300 ke. V/turn Other losses 50 ke. V/turn Total losses 1350 ke. V/turn Beam power 540 k. W 3 % ID losses Energy Acceptance
SR RF RF Voltage 3600 k. V Digital LLRF TRANSMITTER Layout 6 cavities Tube type IOT Number 6 x 2 IOTs Power 2 x 80 k. W Combination Ca. Co
SR RF Transmitter (Thomson) HVPS Cabinet: 36 k. V – 4 A power supply 60 Pulse Step Modulation Cards HVPS New PSM card 700 V – 4 A IOT Cabinet: 80 k. W IOT 400 W SSA Auxiliaries Controls PLC IOT Cabinet
SR RF LS-IOT (Light Source IOT in collaboration with Thales) New cavities with 6 1/8’ coaxial output Tube with wider ceramics Tested in factory at 80 k. W for more than 24 h and at 90 k. W for 1/2 h 6. 8 MHz LS version TV version Improvements
SR RF Ca. Co: 1) Combine 2 IOTs 2) Filter Harmonics 3) Operation with faulty IOT Cavity Combiner
SR RF Ca. Co In routine operation, Ca. Co has performed reliably and without problems.
SR RF Ca. Co Plunger for single IOT operation (actuated with a piston) 80 k. W operation in single IOT
SR RF Co. Stub: Coaxial shortcut using stub tunners To isolate the not operational IOT for single IOT operation
SR RF Co. Stub Power after Costub AT 80 k. W 0. 365 W Initial/ final temperture of the stubs at 80 k. W ü In operation 24ºC/26ºC Arcs Not detected RF Leaks Not observed Power Reflected to the active IOT at 80 k. W Co. Stub Ca. Co 85 W
SR RF Watrax: Waveguide to Coaxial transition 1) Allow water cooling channels in 2) Up to 160 k. W 3) Fit the geometry
SR RF Watrax Maximum CW power: 160 k. W VSWR: 1. 061 Max. peak electric field: 239 k. V/m Power dissipated: 74. 1 W
SR RF Watrax: Power test at DESY 250 k. W
SR RF RF cavity: DAMPY - HOM damped cavity (in collaboration with Bessy) HOM damped RF cavity Wire on which beads are attached Bead motion bead Alignment Tension CAVITY DAMPY Type single-cell Number 6 Frequency 500 MHz Rsh 3. 3 Mohm
SR RF SR Dampy 01 to 06 Power tests All cavities operate without problems
SR RF Digital Low Level RF üBased on a commercial FPGA board (Lyrtech VHS-ADAC) üAnalog Front Ends for pre-processing of RF signals üAmplitude, phase and tuning loops implemented ü Diagnostics and extra capabilities Lyrtech Digital Board Analog Front End
SR RF DLLRF Power test Tests at 75 k. W Amplitude RMS Errors: 0. 11% @ 80 MHz 0. 03% @ 1 MHz Phase RMS Errors: 0. 05º @ 80 MHz 0. 02º @ 1 MHz
Conclusion RF developments at ALBA: • • • Cavity Combiner Ca. Co Coaxial Short-Switch Co. Stub IOT improvements LS-IOT HOM Damped Cavity Dampy Waveguide-Coax transition Watrax Digital LLRF DLLRF Thank you
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