Scraps of text for incorporation in the VIS Meeting Minutes

KAGRA/Subgroups/VIS/MeetingNAOJ

Type B (Mark)

Report for week of 8/13

• KAGRA was closed Mon/Tue 8/13-14 due to Obon.
• Enzo and team investigated an issue with the height of the SR3 keystone coupling to yaw of the payload as measured by the OL. We suspect a ferromagnetic item on the SF damper, but we're not sure.

Report for week of 8/20

SR3

• Hatoya-san and Enzo gathered date for a study of yaw mode Q damping time as a study of damper ring height.

SR2

• We continued with cabling work.
• We configured a second pico driver and connected it.
• We assembled the LBB damper rings in the tank, craned them to near the top and hooked them. While the tank was open we also set to nominal height the jacks below the mushroom that will support the suspension.

SRM

• We reserved and configured two pico drivers.
• We checked the prism gluing - all the jigs came away successfully.
• Fabian assembled the RM.
• Hirata-san added ballast masses to the IM and we weighed it, as well as the RM and the optic in the mirror box.
• We suspended the optic and RM.

Report for week of 8/27

Arc weights

• We did an inventory of arc weights to see if we had enough for SRM. Including the weights on the pallet, some weights left over from the BS, and the weights already on SR3, we have enough for a basic allocation for all of type B (172 kg for BS and 103.2 kg per SR) but with only 5 kg spare for tuning.
• We brought all the arc weights into the cleanrooms and divided them up for the SRs.
• Hirata-san cleaned up 1 large arc weight and 3 mediums left over from the BS that got wet during the heavy rain.

SR3

• Using SR3, we did a quick study of the IP frequency as a function of the number of arc weights, to see how much more we might need. 3 pairs of small arc weights (10 mm thick, 4.53 kg each) brought the frequency below 0.1 Hz, 4 pairs made it unstable. If SR3 is typical we would need about 27 kg extra per suspension.
• After the IP study, we left three pairs of 10 mm arc weights installed on the IP and measured the frequencies with the digital system (instead of a stopwatch). Both L and T were around 0.08 Hz, which is good.
• We unclamped the LBB damper rings, installed the rods down to the LBB and hooked the LBB. Mirapro then moved the SR2-SR3 duct to give more space at the SR2 end.

SR2

• We finished routing the in-vacuum cables, and started connecting everything through to the rack for final testing.

SRM

• Panwei calibrated 6 OSEMs to be used on the IM. Two OSEMs have a long-term drift issue and may need repair. He took some long time series to characterize the drift.
• We assembled and installed the bottom section of the security structure under the optic and RM.
• We set up a new OL for setting the pitch. We found the reflection off the AR surface was much weaker than for SR2 and SR3, but fortunately the HR surface is almost flat (ROC≈300 m) and the reflection is weak but better so we were able to use the HR side instead.

Plan for week of 9/3

• Mark, Fabian, Kozu-kun, Panwei at Kamioka Mon-Fri.
• Enzo at Kamioka Mon-Thu.
• Hirata-san at Kamioka Tue-Fri.
• Major crane inspection Mon/Wed mornings using space where Type B work table is. SR2 craning will have to fit in around it.

SR2 (highest priority)

• Connect cables through to rack.
• Check/tweak alignment of chain.
• Add arc weights (103 kg) and geophones - check IP.
• Go/no-go test of electronics.
• Crane in SR2.

SRM (lower priority)

• Set pitch of SRM and RM, tighten clamps, remove winch system.

Etc

• Inspect all crane slots (SR, BS, PR) and check for missing bars and curtains.
• Prepare for scheduled power outage on 9/10.

Plan for week of 9/10

• Monday 9/10 is scheduled power outage.
• Mark in US (job interview).
• Hirata-san, Fabian, Kozu-kun, Panwei at Kamioka Tue-Fri.
• Enzo at Kamioka Tue-Thu, then JPS Meeting Fri, then vacation.

Etc

• Recover from power outage.

SRM (highest priority)

• Weigh IM/... section.
• Build up SS to BF level.
• Add BF.
• Suspend IM and tweak height/balance.

Plan for week of 9/17

• Monday 9/17 is holiday (Respect for the Aged Day).
• Enzo on vacation.
• Mark, Hirata-san, Fabian, Panwei at Kamioka Tue-Fri.

SRM (highest priority)

• Cable/test BF.
• Install IRM.
• Install/cable/test IM OSEMs.

SR2 (lower priority)

• Move SR2 in-air cables.
• Remove First Contact.
• Unlock and realign suspension.

Plan for week of 9/24

• Monday 9/24 is holiday (Autumn Equinox).
• Mark, Hirata-san, Fabian, Panwei at Kamioka Tue-Fri.

To-Do Lists, Schedule

• KAGRA/Subgroups/VIS/TypeB/ToDoBS

• KAGRA/Subgroups/VIS/TypeB/ToDoSR

• JGW-L1807779 Type B Schedule (SR)

Vacation Info

• Mark: 9/10-14 (job interview in US).
• Enzo: 9/14 JPS, 9/15 through 10/8 vacation in Chile.