jeffrey.kissel@LIGO.ORG - posted 14:50, Wednesday 06 May 2026 - last comment - 15:29, Wednesday 06 May 2026(90139)
First In-vac Components for SPI Pathfinder Installed!! ISI HAM2 (ISIJ) Reflector Assembly Installed and Cabled up to Feedthrus
J. Kissel, J. Warner ECR: E2400026 WPs: 13237, LHO:13238 Final Design Doc: T2400145 Relevant Systems Level Drawings: . Mechanical Assemblies :: ISIJ Reflector D2400102 :: HAM Table Baffles D1700335 :: HAM2 Systems Layout D0901083 (not yet-inclusive-of-SPI) . Electronics Wiring Diagram . Cable Routing In-vac Cable Routing Plan from G2401479 (pages ) . Flange Layout D1002873-v11 Executive summary: - Removed ISIJ +X-side, center, HAM2 ISI table baffle from D1700265-v4 Type 2 :: Bracket mounting bolts left screwed into ISI optical table for this will eventually become a D1700265-v4 Type 3 and remounted. - Installed ISIJ Reflector + QPD Assembly D2400102 on +X ISI side wall (D071057-v2), with its shroud (D2500030) in place :: We didn't weigh it, but the SW Assembly predicts a mass of 1.96 [kg], which we can likely round up to 2.0 [kg] with the shroud installed. - Routed and connected QPD read-out cable system to D3 flange, F10 spigot. - Routed and connected picomotor cable system to existing D1101515 quadrupus leg Cable #3, J4 :: Cable #4, J5 is connected to IO PM5 mirror, Cables #2 J3 and #1 J2 were reset in neat coil with connectors floating to avoid electrical grounding as before. - Nudged make-shift baffle system using D1700261 ballast mass baffle mounted vertically on the +X / +Y / Beam Height corner of the chamber wall upon entry into beamtube. :: the will DEFINITELY need a technically-minded reset. In at 10:30a PT and out by 12:30a PT. It's so lovely when everything goes to plan! Pictures and further info to follow in the comments below.
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Removing Center ISI Table Baffle Not much to say more here -- removal was easy. We tried "just" removing the panel using the the coated/capped screws, but these didn't budget upon several attempts with Jim's fingers and grunts. So, elected to fight that battle outside the chamber and removed the whole assembly at the table mounting point. The full assembly is wrapped in dry-wipes, foil, and ameristat bagged and in Mitch's office while it waits for the Type 03 version of the panel to come out of clean-n-bake.
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Installation of ISIJ Reflector itself Also not much to say, other than the great joy that the drawings of the D071057-v2 ISI Side Wall have the irregular positions of the 1/4-20 utility holes accurate enough that Bram's CAD-informed-only mounting holes for the ISIJ reflector's baseplate of the reflector lined up without issue. *phew* Also -- the D2400102 drawing doesn't highlight which length 1/4-20 bolt should be used for mounting, so we used 1/4"-20 x 0.625"L (5/8"), which was "just enough." Pictures from the main entry are the best "big picture" views, but here I attach a few more in case the need arises.
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QPD Cable Routing
We didn't get dedicated pictures of this QPD cable routing but,
- it follows the plan on page 22 of In-vac Cable Routing Plan posted to G2401479-v3,
- You can see the ST1 portion of it well-enough in the above pictures,
- Jim did the routing, so I trust that there's a healthy loop in the jump from ST1 to ST0, and
- I attach a picture here of the record that we've connected it to D3-F10, and a copy of the "F-Type" (D2000225-v1) counting from page 18 of the above mentioned cable routing plan.
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Picomotor Cable Routing BEFORE INSTALL Just because we knew little about the details of this cable system ahead of time given how ancient the PM5 picomotor actuated mirror system, I got a lot of good "before" pictures. Mostly, I confirm that PM5 does use the Cable #4 J5 leg of the D1101515 quadrupus, and all the other legs were neatly cable-tied up and away.
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Picomotor Cable Routing AFTER INSTALL Here're photos of the routing of the two 72 [in] length D2400316 picomotor extension cables connected in series and routed to all the way around from the ISIJ reflector on the +X face to the -X / +Y corner of the table where CB-9 and the D1101515 quadrupus lives. I paid particular attention to the connectors and made sure they were left floating and not shorting to anything metal. I also re-bundled up Cable #2 J3 and Cable #1 J2 in coil similar to the before pictures, again ensuring that the connectors are floating in both space and electrical connection.
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The Nudged Chamber Wall Baffle Some pictures of the baffle that we nudged that will likely need re-alignment.
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