40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
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Entry  Mon Jul 26 20:12:18 2010, kiwamu, Update, SUS, OSEMs on PRM DSC_2279.JPG
    Reply  Tue Jul 27 21:38:21 2010, kiwamu, Update, SUS, installation of in-vac optics DSC_2284.JPGDSC_2291.JPG
       Reply  Wed Jul 28 17:32:37 2010, kiwamu, Update, SUS, installation of in-vac optics 
          Reply  Thu Jul 29 10:39:43 2010, kiwamu, Update, SUS, Re: installation of in-vac optics 
Message ID: 3302     Entry time: Tue Jul 27 21:38:21 2010     In reply to: 3294     Reply to this: 3313
Author: kiwamu 
Type: Update 
Category: SUS 
Subject: installation of in-vac optics 

[Alberto and Kiwamu] 

We put the PRM back approximately on the right place.

Also we installed the pick off mirrors and the PZT mirror.

Since the main beam after the MMT still has not been well aligned , we put those optics approximately on the right place. A fine alignment of those will be performed later

The offsets of the PRM OSEMs are still kind of okay.

The next things we have to do are

(1) installation of a tip-tilt for the SRC, (2) alignement of those optics by using the main laser and (3) installation of the green optics.


what we did

 1. put the PRM back to the designed place.

     - After this, we released the PRM from the earthquake stops and turned on the damping servo.

      - Now the earthquake stops are at a distance of approximately 1mm from the PRM. These separation distances were tuned by counting the turn number when we screwed them off.

 2. leveled the table

 3. adjusted the separation distances from the PRM to the OSEMs.

    - The table below summarize the current OSEM offsets. LL may still need to be adjusted.

  Max./2 [V]

measured offsets [V] 

after adjustment 

discrepancy [%]
UL 0.874 0.928 + 6.2 %
UR 0.848 0.777 - 8.4 %
LL 1.038 0.796 - 23 %
LR 0.967 0.845 -12 %
SD 0.840 0.745 - 11%

 4. put the PZT mirror on the right place.

      -  This PZT mirror is going to be used for beam steering after the MMT.

 5. put the pick off mirror and its associated optics.

     -  This pick off mirror provides with the beam eventually going to IP_ANG and IP_POS.


current status

The table below shows the current status of the installed optics.

Red letters represent the incomplete states which still need further adjustment.

Blue letters represent the complete status which don't need any further adjustment.


name on the drawing

(see the wiki ) 

BS tower BS well aligned by a caliper
PRM tower PRM approximately aligned. LL OSEM
TIp-TIlt PR3 approximately aligned
Pick off Window (wedged) IPPO

wedge is correctly set (fat part is on the left).

 approximately aligned

steering mirror IPPOSSM1 mirror is correctly flipped. approximately aligned
steering mirror IPANGSM1 mirror is correctly flipped. approximately aligned
steering mirror IPANGSM2 approximately aligned
pzt mirror SM2 approximately aligned


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