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Message ID: 15953     Entry time: Mon Mar 22 16:29:17 2021
Author: gautam 
Type: Update 
Category: ASC 
Subject: Some prep for AS WFS commissioning 
  1. Added rough cts2mW calibration filters to the quadrants, see Attachment #1. The number I used is:
              0.85 A/W         *       500 V/A            *          10 V/V                              *         1638.4 cts/V
    (InGaAs responsivity)     (RF transimpedance)  (IQ demod conversion gain)      (ADC calibration)
  2. Recovered FPMI locking. Once the arms are locked on POX / POY, I lock MICH using AS55_Q as a sensor and BS as an actuator with ~80 Hz UGF.
  3. Phased the digital demod phases such that while driving a sine wave in ETMX PIT, I saw it show up only in the "I" quadrant signals, see Attachment #2.

The idea is to use the FPMI config, which is more easily accessed than the PRFPMI, to set up some tests, measure some TFs etc, before trying to commission the more complicated optomechanical system.

Attachment 1: AS_WFS_head.png  64 kB  Uploaded Mon Mar 22 17:44:04 2021  | Show | Show all
Attachment 2: WFSquads.pdf  144 kB  Uploaded Tue Mar 23 01:28:36 2021  | Show | Show all
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