Scraps of text for incorporation in the VIS Meeting Minutes

KAGRA/Subgroups/VIS/MeetingNAOJ

Type B (Mark)

Report for week of 7/30

===== SR3 ======

• We undid the accidental misalignment of the SR3. We also switched off the BF GAS offset we had been using, let the IM rise until near zero on the BF LVDT, and adjusted the IM vertical OSEMs back to mid-range.
• We closed control loops for the SR3 GAS filters.

SR2

• We installed the SR2 SF damper magnet ring but found that the magnet pattern didn't match the Cu segments due to a different in the caps between SR3 and SR2. We raised the ring but left it suspended, clamped the template to the underside and rearranged the magnets.
• We did a vertical height budget of the SR2. It turns out to have a very similar issue to the SR3: the chain is about 5 mm longer than the CAD, with about 3 mm of that between the SF and BF. We decided to do the same fix and operate with the F0 keystone 5 mm higher. We chose an total amount of ballast to give that keystone height and secured most of it to the SF, keeping a reserve for cables and the yaw stepper.

SRM

• We moved the SRM assembly frame into its final position, reset it to the initial configuration, double-checked the heights of the crossbars, and lowered the optical table by 3 mm (to give margin for the optic to rise during hanging, which we had kept forgetting to do). We cleaned it up with the airgun and wet-wipes. We installed the IM ring and IM.
• We assembled the SRM metal mass. Hirata-san made a jig from a plate with 4 screws which could safely hold the delicate front Sol-Black-coated ring upside down while the rest of the components were mounted on it.
• We moved the metal mass to the mirror box and added the prisms and magnet standoffs.

Plan for week of 8/20

• Mark, Enzo, Hirata-san, Fabian, Kozu-kun, Terrence, Panwei at Kamioka Mon-Fri.
• Terrence and TBD at f2f on Friday 8/24.
• Kozu-kun works at Mozumi Mon, Fri.

SR3

• Finalize optic pitch, OSEM alignment.
• Do TFs with temporary OL.
• Install final OL.
• Hook LBB, add ballast mass.
• Tune IP.

SR2

• Do vertical height budget.
• Choose F0 keystone height.
• Add estimated final ballast mass.
• Do PI cable routing.
• Adjust ballast/trim mass, with reserve for cables.
• Stage LBB damper rings in tank.

SRM

• Assemble metal mass.
• Glue prisms, flags.
• Reconfigure, align assembly frame.

To-Do Lists, Schedule

• KAGRA/Subgroups/VIS/TypeB/ToDoBS

• KAGRA/Subgroups/VIS/TypeB/ToDoSR

• JGW-L1807779 Type B Schedule (SR)

Vacation Info

• Terrence: 8/24-26 f2f, then returns to Hong Kong.
• Enzo: 9/14 JPS, 9/15 through 10/8 vacation in Chile.