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Message ID: 497     Entry time: Sun May 25 20:30:25 2008
Author: rana 
Type: Summary 
Category: PSL 
Subject: PMC Mode Matching 
I checked the PMC mode matching by ramping the gain down to -10 dB (from +20 dB) and
moving the DC offset around until it caught lock on the different HOMs. Then I recorded
the output power (PMCTRANSPD). The DC offset on this EPICS channel was -0.013 V, so I
used its AOFF field to zero this out. Here is a list of the power in the largest modes:
Mode    Power (V)
----    ---------
00        2.7
10        0.2
04        0.04
02        0.02
BE        0.36      **Bull's Eye mode is TEM02 + TEM20. This can be fixed by lens adjustment.


N.B. To make a PNG file with DTT, just make an EPS file -- then use the eps2png perl script.
Attachment 1: pmc.png  38 kB  Uploaded Sun May 25 21:32:21 2008  | Hide | Hide all
pmc.png
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