cheryl.vorvick@LIGO.ORG - posted 17:05, Monday 06 November 2017 - last comment - 18:29, Monday 06 November 2017(39305)
IO, as of Monday, Nov. 6th
Today:
- IM4 pitch adjusted
- required removing the IM4 SiC baffle
- required loosening both lower EQ stop brackets to allow the inner SiC baffle to clear the EQ stop brackets
- the pitch adjustment screw/sleeve was turned less than 1/2 of a turn
- current IM4 pitch, with zero alignment bias, is -124urad
- loosened blade attachment blocks to correct a ~-1100urad yaw with zero alignment slider
- current IM4 yaw, with zero alignment bias, is -144urad
- IM2 yaw adjusted
- loosened blade attachment blocks to correct the 2000 slider drive in yaw
- IM2 yaw, with zero alignment bias, was ~-1500urad
- current IM2 yaw, with zero alignment bias, is -36urad
- IMC irises placed in HAM2 and HAM3
- beam from PSL aligned to the IMC with the PZT
- IMC is flashing
Tomorrow:
- brief start to the day with laser safe - still some irises to place downstream of the IMC
- once that's done, will need the beam to continue the IO alignment
- Cheryl JeffK, JeffB, PeterK
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On The IM4 Cage Baffle Assembly D1002745 This aLOG is merely to provide data on the troublesome IM4 baffle assembly such that it might be improved in some vent in the future. As one may recall, in order to adjust the pitch alignment of the IMs / HAUX / HAM Auxiliary suspensions, one must remove their cage protection baffle. Recall that each of the IMs have their individualized cage protection baffle, Optic Former Baffle Name Drawing / Assembly IM1 SM1 D0902378 IM2 PMMT1 D0902380 IM3 PMMT2 D0902382 IM4 SM2 D1002745 where IM1's baffle has a large opening, IM2 and 3's are (from what I can tell) identical, and IM4 has much larger coverage, and has a special insert D1002722 in order to provide further protection for the suspension wires against stray IFO REFL beams during lock loss. It is this special insert that gives us the most trouble when taking the IM4 baffle assembly on and off, because it does not clear the suspension cage's front (HR-side) earthquake stop brackets (D1000539, D1000540, D1002360, D1002361) when they're secure. One needs to loosen bolts and back off these EQ stop brackets to remove this baffle. Attached are several pictures: (1) & (2) show the baffle assembly after removal from the IM4 cage (3) show the drawing numbers for each baffle part (4) shows the metal erosion at the baffle's contact points with the EQ stop brackets (5) shows IM4 after the baffle has been removed, highlighting the EQ stop brackets (6) & (7) show the particulate that erodes off of the baffle every time we remove & re-install it. The pains experienced during removal and re-install of this baffle assembly are not new. Kiwamu and I had trouble in the last vent when we were mechanically relieving the alignment sliders (see the bottom of LHO aLOG 12811) and during original install by Cheryl and Deepak (see 5633) LLO aLOG 3814 seem to imply that something was done chamber-side to L1 IM4 to make the baffles fit better.
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