Reports until 01:18, Wednesday 22 January 2014
H1 SUS
kiwamu.izumi@LIGO.ORG - posted 01:18, Wednesday 22 January 2014 - last comment - 09:58, Wednesday 22 January 2014(9415)
PRM and BS transfer function measurements launched

I launched a L2P(Y) transfer function measurement on PRM and BS.

The coil gains for the M2 stage of BS were set back to the ones Keita set on 24th of December (see alog 9079):

Before I changed these numbers they had been:

Therefore all the BS actuators on the M2 stage has now different sign. We should remember this, especially when locking the Michelson. I have no idea of why we kept using these funny +/-1 things instead of the balanced coil gains.

Comments related to this report
kiwamu.izumi@LIGO.ORG - 01:23, Wednesday 22 January 2014 (9416)ISC
Link

PR2 is intentionally misaligned to avoid a fringe showing up in REFL_WFSs. PRM is slightly misaligned on purpose to have the reflected light centered on REFL_WFS_B.

kiwamu.izumi@LIGO.ORG - 01:24, Wednesday 22 January 2014 (9417)
Link

Currently PRM is at:

  • P = -731
  • Y = -340

Its good aligment to get PRMI fringe is

  • P = -671
  • Y = -359
kiwamu.izumi@LIGO.ORG - 01:26, Wednesday 22 January 2014 (9418)
Link

Both TF measurements are running on opsws1.

jeffrey.kissel@LIGO.ORG - 08:57, Wednesday 22 January 2014 (9426)
Link 

I've captured new safe.snap for the BS such that these values are stored permanently.
jeffrey.kissel@LIGO.ORG - 09:06, Wednesday 22 January 2014 (9427)
Link 

S. Ballmer, J. Kissel

The setup for the beam splitter transfer function was invalid, because the off-diagonal elements of the DRIVEALIGN matrix (i.e. filters for we're trying to re-measure the design data) were still on. We've also noticed that the coherence below 0.5 [Hz] is still poor. I'm going to re-tune the low frequency drive with higher amplitude drive for a bit, and then re-launch the measurement in the appropriate configuration.
kiwamu.izumi@LIGO.ORG - 09:58, Wednesday 22 January 2014 (9431)
Link

oops!