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Entry  Mon Sep 15 18:29:47 2014, Evan, DailyProgress, BEAT, Attempts at scatter reduction 
    Reply  Tue Sep 16 15:08:57 2014, Evan, DailyProgress, BEAT, Attempts at scatter reduction 
Message ID: 1519     Entry time: Mon Sep 15 18:29:47 2014     Reply to this: 1521
Author: Evan 
Type: DailyProgress 
Category: BEAT 
Subject: Attempts at scatter reduction 

I went through the table today looking for ghost beams. Most were already dumped. For those that weren't, I put down a dump or an iris.

I again looked at TTFSS OUT2 with the cavities unlocked (i.e., the open-loop error signals) and found that the low-frequency seismic/scatter wall appears only on south. So I hunted around south for a while. I found a series of ghost beams reflecting off the EOAM input and hitting dangerously close to the EOM output aperture. So I moved the EOAM forward a few inches, then adjusted its kinematic mount to offset these beams a bit. The EOAM should be realigned, and we should check to make sure the ghost beams are not entering the EOM again.

With the increased space between the EOM and EOAM, I installed a flipper mirror that takes the beam to the 1811. Then I minimized the RAM (from –54 dBm to –72 dBm with 85 mV dc).

FM dev: 10 kHz

Averages: 10, 50, 100, 500

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