40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log  Not logged in ELOG logo
Entry  Tue Jan 29 20:28:11 2013, ericq, Update, General, Early work on Mirror Mounts early.pdf
    Reply  Wed Jan 30 03:01:55 2013, Koji, Update, General, Early work on Mirror Mounts 
Message ID: 7958     Entry time: Tue Jan 29 20:28:11 2013     Reply to this: 7960
Author: ericq 
Type: Update 
Category: General 
Subject: Early work on Mirror Mounts 

 [Q, Chloe]

Chloe has been to the lab twice to start up her investigations in acoustic noise coupling to mirrors. The general idea for the setup is a HeNe laser bouncing off a mirror and onto a QPD, whose signal provides a measure of beam displacement noise. The mirror will be mounted and excited in various ways to make quantitative conclusions about the quality of different mounting schemes.

We have set up the laser+mirror+QPD on the SP table, and collected data via SR560s->SR785, with the main aim of evaluating the suitability of this setup. The data we collected is not calibrated to any meaningful units (yet). For now, we are just using QPD volts.

Chloe collected data of vertical displacement noise for the following schemes: Terminated SR785 input, Terminated SR560 inputs, Laser centered directly onto the QPD, Laser shining on mirror centered on QPD, laser/mirror/qpd with some small desktop speakers producing white noise from http://www.simplynoise.com. Data shown below. 

early.pdf

 

 

ELOG V3.1.3-