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Message ID: 9439     Entry time: Wed Dec 4 14:16:42 2013
Author: Jenne 
Type: Update 
Category: LSC 
Subject: PRFPMI flashes on transmission QPDs 

2 weeks ago I took some data, and remembered today at the 40m meeting that I hadn't posted it.  Bad grad student.

All I'm trying to show here is that we see flashes in the arms that are larger than the ~50 units that we see saturate the Thorlabs transmission PDs. For arm power values below ~50, the QPD sum and Thorlabs PDs give approximately the same values.  So, 1 unit on the Thorlabs PDs is equivalent to 1 unit on the QPD sum, and 50 units on the Thorlabs diode is equivalent to 50 units on the QPD sum.

The situation was arms held on resonance with ALS, and the PRMI was flashing.

ArmsResonatingUsingALS_PRMIflashing_TRX_TRY.pdf

Arm powers of ~140 imply a power recycling gain of ~7.

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