Reports until 16:31, Tuesday 24 December 2013
H1 SUS
keita.kawabe@LIGO.ORG - posted 16:31, Tuesday 24 December 2013 - last comment - 18:00, Monday 13 January 2014(9087)
OSEM calibration of TMSX, ETMX and ITMX

References: D1201036 (BSC9 ACB assy) and D1200314 (BSC3)

Gerardo read the distances between the baffle diodes off of CAD drawings for me (see the attached cartoon). 

ITM baffle PD1-PD4 separation is 11.3" over 4km (72 urad) both horizontally and vertically. For ETM the number is 11.8", so it's 75 urad.

Don't know why the patterns are different for ETM and ITM, but using these we can calibrate TMSX, ITMX and ETMX bias sliders. Note the factor of 2 between TMS and mirrors, this is because TMS moves with the beam but mirrors don't.

  TMSX P TMSX Y ITMX P ITMX Y ETMX P ETMX Y
PD4-PD1 [urad in slider offset]

187-118

= 69

-253+190

= -63

99-66.6

= 32.4

-38+72.9

= 34.9

355-310

= 45

-34-26.5

= -60.5

Slider Calibration

[urad/urad]

72/69

= 1.04

72/63

=1.07

75/32.4/2

= 1.2

75/34.9/2

= 1.1

72/45/2

=0.8

72/60.5/2

= 0.6
Slider sign positive=down positive=out of L positive=down positive= inside of L positive=down positive=out of L

 

Calibration of ETMX is somewhat suspect (at 10urad level) because of the fact that the position loop of EX ISI got accidentally off before I did ETMX adjustment.

Images attached to this report
Comments related to this report
keita.kawabe@LIGO.ORG - 09:50, Tuesday 07 January 2014 (9133)
Link

There's an update on this. Nothing changed significantly, but anyway see the alog below:

https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=9126

keita.kawabe@LIGO.ORG - 18:00, Monday 13 January 2014 (9247)
Link

One error in the table, TMSX Y calibration = 1.14 urad/urad instead of 1.07.