With Hirata-san and Washimi-san.

Pictures at SR3 remedying work after O3.

• Temperature 22.9 degrees.
• I removed the 4 grams from the top of the IM on the -Y side.
• We set BF LVDT to zero with coil-magnet actuation.
• We were able to recover the TM-P (per oplev readout in ndu) with -1365 counts of IM-P coil-magnet actuation.
• Now IM-P is  -406 urad (IRM is locked and partially disassembled, therefore, this is a relative measurement useful in this context only).
• I removed the IM-P coil-magnet actuation.
• IM-P them becomes  372 urad (again, this is a relative measurement useful in this context only).
• This means that in our latest ballast mass adjustment we disturbed the pitch by 778 urad (in a previous entry I had written appromately 600 urad).
• I adjusted IM-P with the picomotor:
  • TM-P around zero (per oplev in ndu).
  • IM-P around -409 urad (again, this is a relative measurement useful in this context only).
• This means we don't need to redistribute ballast mass on the IM to modify pitch.
• I removed the coil-magnet actuation in the BF and it went up to 379 um; it's higher than yesterday because the temperature went down (now 22.8 degrees). Nevertheless, the distance from the aim is very small: 379 um - 311 um = 68 um; it requires -1500 counts of actuation to bring it to the aimed position.
• Then we proceeded to reassemble the IRM and release the system: we locked the IM, RM and mirror.
• We softly tightened the ballast masses with an Allen key.
• We measured the position of the shaft of the IM-P picomotor. See the diagram in this notebook page. There will be a separate entry to report the result of this measurement.
• We removed the H1 OSEM flag.
• We put back the front and back panels of the IRM.
• We connected the OSEM and clamped the cable on the front panel.
• We put back the H1 OSEM flag; we set the North out per klog 5035 and notebook notes.
• We released the payload and BF case from the security structure.
• The SF LVDT went up to 1764 um. We will add mass to the BF soon in order to correct this.
• The oplev went out of range, which was expected, lilkely because of the cables.
• IM-P became 1610 urad. (I'm not sure about the reson, but tend to blame coupling via cables.)
• I applied -6100 counts of coil-magnet actuation to bring BF LVDT to zero.
• Measurements of transfer functions in IM-L, T, R, P and Y show a healthy system. I didn't measure IM-V because F0 is locked.
• I removed the coil-magnet actuation in BF, the BF LVDT went up to 300 um (temperature 23.1 degrees with aim 311 um).
• IM-P changed to -1150 urad due to coupling via cables.

The next step woulld be to move IM-P with the picomotor to a suitable value.