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Entry  Tue Feb 1 15:33:28 2022, Koji, Summary, BHD, Optomechanics configuration for the in-vacuum aux small optics Invac_opto_mechanics_v2.pdf
    Reply  Wed Feb 2 18:55:58 2022, Koji, Summary, BHD, Optomechanics configuration for the in-vacuum aux small optics Screen_Shot_2022-02-02_at_6.46.46_PM.png
       Reply  Wed Feb 2 21:16:23 2022, Koji, Summary, BHD, Optomechanics configuration for the in-vacuum aux small optics PXL_20220203_050156031.jpg
       Reply  Thu Apr 28 11:53:10 2022, Anchal, Summary, BHD, POP_SM4 and POP_SM5 Assembly 
          Reply  Tue May 3 14:02:09 2022, Anchal, Summary, BHD, Installed POP path in ITMX Chamber 
    Reply  Thu Apr 14 10:18:35 2022, Paco, Summary, BHD, 2 in oplev mirrors incompatible with LMR2V 
       Reply  Thu Apr 14 18:34:51 2022, Paco, Summary, BHD, ITMY Oplev reinstalled (Re: 2 in oplev mirrors incompatible with LMR2V) 
Message ID: 16817     Entry time: Thu Apr 28 11:53:10 2022     In reply to: 16640     Reply to this: 16826
Author: Anchal 
Type: Summary 
Category: BHD 
Subject: POP_SM4 and POP_SM5 Assembly 

POP_SM4

I tried out this stack today and found some change of plans.

  • The attachment in elog 40m/16640 says to use 1/4-20 silver coated non-vented screws for joining BA2V to PLS-T238, however PLS-T238's bottom hole is a blind hole and is not vented. So we actually required <1 in long silver plated vented 1/4-20 cap screw for this purpose. Jordan and I were only able to find the correct length silver plated screw but it is not vented. So we decided to make a venting hole on the post from the side.
  • I had to use a 0.14" spacer as washer between PLS-T238 and BA1V. The 1" post shim that Koji got for this purpose had too small a hole in the center to let the 8-32 screw pass (I know, weird). but I think we had 3 spare 0.14" ad we bought 10 when we required 7, so we should be good.
  • The attachment in elog 40m/16640 also says to use 8-32 silver coated vented setscrew for joining TR-1.5 to LMR1V mount. I found one vented silver coated set screw nearby in the clean room but it turned out to be too long. Worse, I overtightened the setscrew when trying this connection which damaged the inner threads of one of the LMR1V. So we need to buy one more LMR1V (maybe an additional spare too) for future installation of OMC1R1/OMC2R1.
    • Then Jordan and I searched for a smaller silver coated and vented 8-32 setscrew but didn't find any. Jordan also noted that LMR1V is an aluminium mount and we should not use silver coated setscrew with it. Since the TR-1.5 mount is ok to be sacrificed if a cold weld happens, we'll just use an uncoated SS 8-32 setscrew to join TR-1.5 and LMR1V. We could not such vented setscrews, but we have plenty of non-vented once. So Jordan is going to make a venthole in TR1.5 top end as well. LMR1V already has a vent hole on its side.

tl,dr; Jordan is preparing PLS-T238 and TR-1.5 with venting holes and C&B and they would be ready by tomorrow. I have collected all other parts for assembly, still looking for the mirror but I know other lab members know where it is, so no big issue there.


POP_SM5

The assemly of this mirror is complete. A slight change here as well, we were supposed to use the former POYM1 (Y1-2037-0) mirror for POP_SM5 but I could not find it. It was stored on the right most edge of the table (see 40m/16450), but it is not there anymore. I found another undocumented mirror on the flow bench on the left edge marked (2010 July: Y1-LW1-2037-UV-0-AR) which means this mirror has a wedge of 1 degree and an AR coating as well. We do not need or care about the wedge or AR coating, so we can use this mirror for POP_SM5. Please let me know if someone was saving this mirror for some other purpose.


I'll finish assembly of POP_SM4 tomorrow and install them in ITMX chamber and resurrect POP path.

Quote:

Here is more detail of the POP_SM4 mount assembly.

It's a combination of BA2V + PLS-T238 + BA1V + TR-1.5 + LMR1V + Mirror: CM254-750-E03
Between BA1V and PLS-T238, we have to do a washer action to fix the post (8-32) with a 1/4-20 slot. Maybe we can use a 1" post shim from thorlabs/newport.
Otherwise, we should be able to fasten the other joints with silver-plated screws we already have/ordered.

I think TR-1.5 (and a shim) has not been given to Jordan for C&B. I'll take a look at these.

 

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