Linac Coherent Light Source (LCLS) Low Level RF System New RF System Commissioning Experience April 16, 2007. Safety. Hazards in the LLRF system RF 1kW at 120Hz at 5uS = 0.6 Watts average, 2 Watt average amps at 2856MHz, 60W average amps at 476MHz Hazards – RF Burns
Linac Coherent Light Source (LCLS) Low Level RF SystemNew RF System Commissioning ExperienceApril 16, 2007
The new control system will tie in to the IPA Chassis with 1kW of drive power available. Reference will be from the existing phase reference line or the injector new RF reference
I and Q will be controlled with a 16bit DAC running at 102MHz. Waveforms to the DAC will be set in an FPGA through a microcontroller running EPICS on RTEMS.
Gun – About 1 Week to Full Power
L0A – About 2 Weeks to Full Power
Most stations were and still are gassy by the klystron.
L0B – About 2 weeks to Full Power
L1S – Easy 1 Week to Full Power
Amplitude Waveform flat to +-2% Phase Waveform flat to +-2 Degrees
Pulse width of 1.2uS and >600nS of waveguide eliminates klystron power change due to reflected power and need for circulator.
SLED Amplitude Waveform
Phase Waveform flat to +-2 Degrees
Over fill time of structure