aLIGO LHO Logbook

H1 ISC

stefan.ballmer@LIGO.ORG - posted 16:16, Monday 25 July 2016 - last comment - 17:06, Friday 29 July 2016(28627)

Script for moving the beam spot on PRM only

Following the same idea as elog 28442, here is a script for moving the beam spot position on PRM (prmspotmove.py).

It monitors IM3 slides, and moves IM4, PRM and PR2 sliders in such a way the the beam spot positions on PR2 and PR3 don't change.

The script was tuned in INPUT_ALIGN (for IM4 and PR2 matrix elements) and PRM_ALIGN (for PRM matrix elements).

Matrix elements (in rad /rad IM3)

pitIM3toPR2=+0.0022;
yawIM3toPR2=+0.0055;
pitIM3toIM4=-1.3;
yawIM3toIM4=+0.92;
pitIM3toPRM=-0.009;
yawIM3toPRM=+0.031;

Also attached is the python script used for finding the matrix element, getMx.py.

Non-image files attached to this report

Comments related to this report

stefan.ballmer@LIGO.ORG - 17:06, Friday 29 July 2016 (28747)

Here is the theoretical matrix for this move (note that signs will vary for pitch and yaw):

IM4/IM3=-1.022385686091801*tim3;

PR2/IM3=0.069871106113604*tim3;

PRM/IM3=-0.350788523435222*tim3;

This was calculated with the following data (in meters):

RPRM=-11;

RPR2=-4.555;

RPR3=36.0;

RITM=1939;

LPRM=16.6128;

LPR2=16.1551;

LPR3=24.88797;

LARM=3994.5;

LIM4=0.413;

LIM3=1.17;

n=1.45;

f=-RITM/(n-1); # thin lens approximation

fm=-RPRM/(n-1); # thin lens approximation