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ALBA RF: Commissioning & Status Francis Perez. The RF Group: Bea Bravo Jesus Ocampo (since 19 Sept. 2011) (Paco Sanchez and Angela Salom). Support Engineering Division Support Computing Division Support Operators Group. ALBA overview and commissioning
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The RF Group:Bea Bravo Jesus Ocampo (since 19 Sept. 2011) (Paco Sanchez and Angela Salom) Support Engineering Division Support Computing Division Support Operators Group
ALBA overview and commissioning • Booster RF System • Storage Ring RF System • Summary
Synchrotron Light Source in Cerdanyola (Barcelona, Spain)
ALBA Accelerators LINAC 100 Mev BOOSTER 100 MeV – 3 GeV STORAGE RING 3 GeV
Booster commissioning in parallel to SR installation: • - 2 weeks in January 2010 • - 2 weeks in July 2010 • - Afternoons in October–December 2010 • SR commissioning (1st phase) March-June 2011. • Installation Insertion Devices: SCW and IVUs. • SR commissioning with all IDs restarted Sept 2011 • Beam for beamlines commissioning 18 October 2011
BOOSTER COMMISSIONING Tune Orbit
SR COMMISSIONING 9th March: Beam spot at 1st FS, at sector 2, 09h00 completely defocused horizontally. All SR Quadrupoles with wrong polarity
Sectors 1&2 • Quadrant 1 • Quadrant 2 • Quadrants 3&4 19h35: 1st turn ! SR COMMISSIONING • Recabling Quads: On axis injection
16 March, 8h50: Beam Acummulated 1.5 mA stored Acummulation Current SR Current Booster
1st synchrotron light outside the tunnel 16 March 2011
23 March - 1st April Once the MPS was operational…
7th June 2011 MAC record!!
Beam size 71 um31 um Emittance = 4.5 nmrad ; Coupling < 2%
Bunch length Streak camera
Beam Image at Fluorescent Screen FE24 (CIRCE) • Screen @ 9.35m from source (middle of straight section) • Source APPLEII undulator EU62 • Stored current I=0.8mA Minimum gap (15.5mm): Horizontal mode (K=5.2) Circular mode (K=3.0) Vertical mode (K=3.7)
Booster Transmitter Operation since November 2009: • After long shut downs, IOT needs reconditioning
Booster Cavity Since November 2009: • Working without problems 35 kW 100 W
Storage Ring RF System Max. RF Voltage 3600 kV Digital LLRF TRANSMITTER Tube type IOT Number 6 x 2 IOTs Power 2 x 80 kW Combination CaCo Layout 6 cavities
SR Transmitters • 13 SR transmitters working since September 2010. 12.000 hours in HV:
SR Transmitters • 23 / 780 HVPS modules failures:
SR Transmitters • Some interlocks no really understood:
IOTs • 13 IOTs positions running • 2 positions with IOT problems: • Tx05: • Reason unknown • Tx07 • CaCo test • Bad re-reconditioning after long shut down (4 months OFF): Arcs in grid
Filament_V Grid_I Ion Pump_I HVPS_I HVPS_V IOT failure Trip: While increasing the power (HVPS current up to 2.9 A) there is a sudden increase of the Grid Current (up to 15 mA) and of the Ion Pump Current (up to 18 uA). Afterwards, some trials to switch the HVPS on were returned with interlocks and then filament OFF due to Filament Voltage Overvoltage. One can see the Filament Voltage increasing after the trip.
IOTs hours Two broken with few hours operation, one after long shutdown.
SR Dampy Cavities • All 6 performing well • Installed and bake-out in situ • Re-conditioned in tunnel • Vacuum problems at pick-up loop ceramic dome
Pick up loops • What happened? • 6 leaky ceramics dome in different situations: 1 after bake-out, 4 during conditioning, 1 during SR commissioning. • Simulations show can not be a field effect • Reason??? Impurities in the ceramics?? Spark observed in the microscope
In addition, soldering problem Pick up loop
Design of the new pick up loop We bought this comercial feedthrough Design by Bea and Filip
Pick up loop: Installation • Low power test: we measured the coupling in Dampy0 (which is not under vacuum and the input coupler is placed at β =1). • S21 = -46 dB (installed in Dampy04) • S21 = -49 dB (installed in Dampy03)
Pick up loop: Installation • Bake out at 140ºC, during 4 days. • Aligned Reference at cavity Laser pointer
Pick up loop: High power test Vacuum Cavity voltage (from new pick-up loop) Power
Waveguide system Ferrite Inc. (USA) • Circulator control by minimising the VSWR: • Measure forward and reflected power • Compute VSWR • Act on the PS of the circulator After reprogramming the circulator`s PLC, with better algorith and full control of the parameters, working without problemes. Rest of Waveguide system ok, including CaCo.
Digital LLRF System All modules installed and working: • Analogue Front ends • Amplitude and Phase Control Loop • Tuning loop • Timing system • RF detectors • Arc detector • Fast Interlock Modules (FIM)
Digital LLRF System But some minor problems during operation: • 1 clock board malfunction • Some cables to be repaired • Some times Auto-Start-Up not working properly Normally some parameter not well adjusted • Some times we observe some phase jumps in the tuning loop (?) • …
Summary • RF system had enough redundancy that the failures did not affect the ALBA commissioning • HVPS running without problems • IOT failures are related to start-ups • Cavity vacuum problems at pick-up loops solved with new design • Waveguide and LLRF systems without major problems • Today: • 6 systems fully operational and calibrated • 1 Dampy cavity under re-conditioning, after new pick up installation