Capture Cavity 1at A0 (@1.8K)

1
Capture Cavity 1at A0 (_at_1.8K)
SIMCON2.1 with MATLAB
SIMCON3.1 with DOOCS
SNS-LLRF with EPICS

• closed loop with maximum gain
• RMS amplitude noise 0.02
• RMS phase Noise 0.2

• closed loop with max gain (250)
• RMS amplitude noise 0.07
• RMS phase Noise 0.2

• closed loop with gain of 40
• RMS amplitude noise 0.4
• RMS phase Noise 0.4
• run with beam

2
Capture Cavity 1at A0 (_at_1.8K)

• SIMCON2.1
• Closed loop with maximum gain
• Achieved amplitude peak to peak noise of 0.07
• Achieved phase peak to peak noise of 0.2
• MATLAB interface ? for development only
• SIMCON3.1
• Closed loop with gain of 50 MAX
• Developed DOOCS control interface
• Achieved amplitude peak to peak noise of 0.4
• Achieved phase peak to peak noise of 0.4
• Run with beam
• SNS
• Closed loop with maximum gain
• Used EPICS control interface
• Amplitude peak to peak noise of 0.02
• Phase peak to peak noise of 0.2

3
Capture Cavity II at Meson (_at_4.5K, no beam)
Running closed loop with FB gain of 12
Running open loop and modifying the cavity
resonance frequency using the piezo actuators
1.04 ms (153 Hz)
Measurement of the cavity half bandwidth 153 Hz
37
4
Capture Cavity II at Meson (_at_4.5K, no beam)

• What weve achieved so far
• Run closed loop, but with a feedback gain of 12
  only (issue under investigation)
• LLRF support for some cryo tests (impact of RF
  power on cryo bath temperature)
• LLRF support for piezo tuner measurements
• What our near term goals are
• Achieve a higher feedback gain
• upgrade SIMCON3.1 firmware
• run at 1.8K
• revise SIMCON3.1 hardware to reduce noise (ADCs,
  I/O, Power supply, external clocks)
• Run CCII using SNS-LLRF system
• What our long term goals are
• Collaboration with DESY for the next generation
  SIMCON board
• RD for an FNAL-LLRF system suited for ILC specs