Reports until 17:19, Wednesday 30 April 2025
H1 ISC
camilla.compton@LIGO.ORG - posted 17:19, Wednesday 30 April 2025 - last comment - 14:38, Monday 02 June 2025(84193)
ISC Alignment Work, Day 1 in HAM1: Majority of REFL Path optics aligned.

Keita, Elenna, Oli, Rahul, Camilla

Summary: Majority of REFL path optics are aligned. Need to beam profile and finish LSC and ASC REFL diode placement on this path and place/check all beam dumps.

This morning, Keita opened the light pipe, locked the IMC  but couldn't see the beam as nicely as he did on AS_AIR yesterday. Since that time he had restored PR2 and PR3 to a time we were last locked. He reverted those changes as we could see the beam back at AS_AIR. Checked again IM4 trans QPD was the same as yesterday.

Additionally M16 was placed roughly in the correct position, all optics are now on HAM1 (apart from PM1) and the class-B pans are empty and packed up.

Left IMC locked.

Comments related to this report
oli.patane@LIGO.ORG - 18:00, Wednesday 30 April 2025 (84213)EPO

Attaching a bunch of photos of the current alignment:

(I don't have the names of the optics on the SLED so I'm calling them by the order that the beam goes through them)

- Alignment from RM2 onto M5 (attachment1, attachment2)

- Coming from M5, through M6, and onto first lens on SLED (attachment3)

- Coming through first SLED lens onto second SLED lens (attachment4)

- Through SLED lenses and onto first steering mirror (attachment5, attachment6)

- Alignment onto SLED pico mirror (attachment7)

- Top view of pico showing that there is available range in both pitch and yaw (attachment8)

- Distance between L1 and front of LSC REFL A (L1 focal length is 222mm) (attachment9, attachment10)

- Distance from LSC REFL A to M18 (attachment11)

- Distance from LSC REFL B to M18 - needs to be moved closer (attachment12)

 

Images attached to this comment
keita.kawabe@LIGO.ORG - 10:02, Thursday 01 May 2025 (84221)

About REFL WFS sled:

  • When the beam was centered by eyeballing on both the 2" lens and the 1" lens, the beam missed the last steering mirror (circled in red) but all other mirrors were without clipping.
  • When the beam was centered on the 2" lens but was off-centered by about 1 mm in +Y direction on the 1" lens (again eye balling), no clipping anywhere but the beam was still closer to the edge of the last steering mirror than I liked.
  • We used the 2nd corner mirror (circled in blue) to steer the beam back to the center of the last steering mirror.
  • Moved the steering mirrors for the WFS heads to place beam dumps at convenient locations.
Images attached to this comment
corey.gray@LIGO.ORG - 14:38, Monday 02 June 2025 (84722)EPO

Tagging for EPO