Keita, Stefan

Yesterday we noticed that our alignment put the spot way low on the ETMY.

So today we tried to set the QPD offsets such that the TMSY well centres its green beam on ETMY. This allows us to use a co-aligned arm as good reference.

1) First we fine-tuned the PZT output matrix to well separate the POS and ANG DoF. We did that by dithering the desired DoF, and watching the camera shots in near and far field (ETMY scatter and TR_Y in the corner). Result:

H1:ALS-Y_OUTPIT_MTRX:
  POS    ANG
  1     -1.2   PZT1
 -0.12   1     PZT2

H1:ALS-Y_OUTYAW_MTRX:
  POS    ANG
  1     -1.25   PZT1
 -0.1    1      PZT2

2) Next we moved the POS DoF until we were happy with the ETMY camera image. We x-checked that by watching the green reflected powers (ITMY was misaligned). We used this to set the QPD offsets:
H1:ALS-Y_QPD_A_PIT_OFFSET 0
H1:ALS-Y_QPD_B_PIT_OFFSET 0
H1:ALS-Y_QPD_A_YAW_OFFSET 0.37
H1:ALS-Y_QPD_B_YAW_OFFSET-0.12

3) We then manually aligned the arm optics to this new beam position. We got an arm build-up of up to 1.09 (H1:ALS-Y_TR_A_LF_OUTPUT), about 10% more than before. Next we need to do the co-alignment.

4) A quick attempt to use the green WFS for that wasn't too successful.

5) We did a manual co-alignment of IR and green. We only got the green TR_Y to about 0.8, but that should be good enough for now. Kiwamu re-centered the DIFF beat note.

Attached are snapshots of the ITMY camera and all the alignment values.
Camera target values:
X-center 336.8
Y-center 238.5