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IMC Information
- Current IMC servo topology:
- Common mode servo board configuration:
SLOW (K1:IMC-SERVO_SLOW_CON_IN1) goes to AOM (and IMC length)
- IMC sideband frequency: 13.78 MHz
- Measured IMC modulation depth: ~0.1 rad
- Measured IMC finesse: 540 +/- 70 (NOTE: 458 from cavity pole, not klogged)
- Measured IMC round-trip length: 53.3 m (Could be slightly different right now since we had re-installation work after this measurement)
- Measured IMC mode matching ratio: 86.2 % (Could be fairly worse right now since we had re-installation work after this measurement)
- Measured MCe RoC: 37.33(9) m
- Measured AOM actuation efficiency: 5.064(7) MHz/V (x2 for double-pass)
- Measured laser PZT actuation efficiency: 1.48 MHz/V (NOTE: 1.26 MHz/V using AOM, not klogged)
- Laser temperature actuation efficiency: not measured yet
- Measured mirror actuation efficiency: 17.2 MHz/V(MCe), 15.9 MHz/V(MCi), 14.9 MHz/V(MCo) @DC (could be wrong; inconsistent between measurements)
http://gwclio.icrr.u-tokyo.ac.jp/lcgtsubgroup/inoutoptics/2015/06/mce625-26.html#comments
- MCe pendulum frequency: 0.955 Hz
- Measured IMC optical gain: 18.6 V/MHz (cavity pole=5.6kHz) (NOT UP TO DATE; we changed laser power, detection optics since then)
- Reference cavity parameters: finesse 1.1e4, length 10 cm (spec), cavity pole 68 kHz
- Counts to volts, volts to counts:
- ADC: 2^16/40 counts/V
- DAC: 20/2^16 V/counts
- IMC oplev calibration:
- Calibrated IMC WFS noise level, and some noise hunting:
- Accelerometer on the PSL table:
IMC length NoiseBudget code:
- Frequency stabilization servo modeling (design):
- Roughly measured beam profiles for Gouy telescope