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==== Past week report ==== ==== Report for week of 3/13 ====
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 * We removed the BF cap to debug the stepper motor. We checked the cabling but didn't find a problem. Eventually toggling the power to the driver box seemed to fix it.
 * We got the wheels removed from the two tall stepladders.
 * We started to rebalance the IM but came to realize that it was unstable for more than trivial pitch and roll (and had been for some time). We moved trim mass from top to bottom and it became unconditionally stable.
 * We rebalance the IM, put back the IRM and adjusted the OSEMs.
 * We took a successful TF in IM-L.
 * We added the security structure ring for below the SF and then added the SF. We noticed the cap is on at the wrong angle (so the keystone lock screws are inaccessible) but we can easily fix that.
 		  * We took a full set of TFs with the BF stationary but the IRM, IM, RM and TM all hanging.
 * We marked peeling or damaged areas on the clean booth floor for Furuta-san.
 * We installed the SF, measuring its weight in the process.
 * We found the crossbars supporting the SF jacks were too high to allow the SF ring to sit on the pillars while also being partially supported by the jacks. (This was an issue with the 3D CAD - the model of the NB-01 jack had a lower minimum height than reality.) We lowered the crossbars by 5 mm and put thicker spacers (12 mm instead of 3 mm) on top of the jacks supporting the SF and everything worked well.
 * We installed newly cleaned L-brackets under the BF and SF.
 * We installed the SF-BF rod and hex cable clamp.
 * We suspended the BF/IRM/IM/RM/BS section and found it was light, presumably because it had been trimmed according to the Promec measurement of the SF, not Hirata-san's later value.
 * We added extra ballast mass corresponding to the difference and found the BF section floated at a good height.
 * We moved trim mass around on the BF until it hung level, and adjusted the IRM and OSEMs until the IRM-IM EQ stops were well-centered and all the OSEMs were centered laterally and mid-range.
 * We ran 11 extra 20-m in-air cables from the tank towards the rack. (We will need to add 10-m extensions.)
 * We connected most of the cables to the vacuum flanges with screws and anti-feedthrough adapters. (Some remain to be done.)
 * We debugged a 900 Hz ringing in the BF LVDT, which turned out to be because the damping was enabled without appropriate filters or gains.
 * We debugged excess noise in the TM-H3 OSEM, which turned out to be mostly due to a faulty cable. However we worry that some of it may be due to some extensions made of non-vacuum-compatible ribbon cable which we added because the TM-H2 and -H3 OSEM cables are too short.
 * We found nearly all the parts for the lower breadboard suspension, including the blades, blade bases, associated cable clamps etc. We also found the jigs for installing the blades.
==== Report for week of 3/21 ====
At Kamioka (Mark, Fabian, Enzo, Perry, Hirata-san):
 * We took a full set of TFs with the SF stationary but the BF, IRM, IM, RM and TM all hanging.
 * We also did a TF from BF LVDT actuation and confirmed that it was working.
 * We got SUMCON running on Perry's computer and worked out how to do cut-down versions of Fabian's full Type B model corresponding to the various partial configurations we have data for.

Scraps of text for incorporation in the VIS Meeting Minutes

KAGRA/Subgroups/VIS/MeetingNAOJ

Type B (Mark)

Report for week of 3/13

At Kamioka (Mark, Fabian, Enzo, Perry, Hirata-san):

  • We took a full set of TFs with the BF stationary but the IRM, IM, RM and TM all hanging.
  • We marked peeling or damaged areas on the clean booth floor for Furuta-san.
  • We installed the SF, measuring its weight in the process.
  • We found the crossbars supporting the SF jacks were too high to allow the SF ring to sit on the pillars while also being partially supported by the jacks. (This was an issue with the 3D CAD - the model of the NB-01 jack had a lower minimum height than reality.) We lowered the crossbars by 5 mm and put thicker spacers (12 mm instead of 3 mm) on top of the jacks supporting the SF and everything worked well.
  • We installed newly cleaned L-brackets under the BF and SF.
  • We installed the SF-BF rod and hex cable clamp.
  • We suspended the BF/IRM/IM/RM/BS section and found it was light, presumably because it had been trimmed according to the Promec measurement of the SF, not Hirata-san's later value.
  • We added extra ballast mass corresponding to the difference and found the BF section floated at a good height.
  • We moved trim mass around on the BF until it hung level, and adjusted the IRM and OSEMs until the IRM-IM EQ stops were well-centered and all the OSEMs were centered laterally and mid-range.
  • We ran 11 extra 20-m in-air cables from the tank towards the rack. (We will need to add 10-m extensions.)
  • We connected most of the cables to the vacuum flanges with screws and anti-feedthrough adapters. (Some remain to be done.)
  • We debugged a 900 Hz ringing in the BF LVDT, which turned out to be because the damping was enabled without appropriate filters or gains.
  • We debugged excess noise in the TM-H3 OSEM, which turned out to be mostly due to a faulty cable. However we worry that some of it may be due to some extensions made of non-vacuum-compatible ribbon cable which we added because the TM-H2 and -H3 OSEM cables are too short.
  • We found nearly all the parts for the lower breadboard suspension, including the blades, blade bases, associated cable clamps etc. We also found the jigs for installing the blades.

Report for week of 3/21

At Kamioka (Mark, Fabian, Enzo, Perry, Hirata-san):

  • We took a full set of TFs with the SF stationary but the BF, IRM, IM, RM and TM all hanging.
  • We also did a TF from BF LVDT actuation and confirmed that it was working.
  • We got SUMCON running on Perry's computer and worked out how to do cut-down versions of Fabian's full Type B model corresponding to the various partial configurations we have data for.

Plan for coming weeks

Next week:

  • Everyone (Mark, Fabian, Enzo, Perry Hirata-san) at Kamioka, Monday-Friday except for Hirata-san Wednesday-Friday).
  • Finish SF installation.
  • Finish BF cabling, hang BF/IRM/IM/RM/BS from SF and confirm weight matches load capacity.
  • Re-trim BF as necessary.
  • Get picomotor driver working.

Week after next:

  • Everyone (Mark, Fabian, Enzo, Hirata-san) at Kamioka, Monday-Friday.
  • Prepare for PI installation.

KAGRA/Subgroups/VIS/TypeB/Minutes (last edited 2022-10-28 10:02:46 by fabian.arellano)