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Entry  Wed Jul 2 18:58:42 2014, Koji, General, General, Beam dump delamination beamdump_delamination.png
    Reply  Thu Jul 3 17:45:18 2014, Koji, General, General, Beam dump delamination beamdump_delamination_solution.png
       Reply  Tue Jul 8 04:08:06 2014, Koji, General, General, Expoxy reapplication for beam dumps 
Message ID: 194     Entry time: Wed Jul 2 18:58:42 2014     Reply to this: 195
Author: Koji 
Type: General 
Category: General 
Subject: Beam dump delamination 

While the OMC breadboard was being inspected, it was found that two out of five black-glass beam dumps showed sign of delamination.
(attached photos).

The base of the each beam dump is a fused silica disk (25mm dia.). The black glass pieces are bonded to the disk. The bond is EP30-2
epoxy without glass beads for bond lining. The disk is bonded on the fused silica bread board with Optocast UV low-viscous epoxy.
The delamination is about 70% of the bonded area. They don't seem to fall off immediately. But the glass pieces are not completely secure.
(i.e. finger touch can change the newton ring fringes) So there might be some risk of falling off during transportation.

The engineering team and I are exploring the way to secure them in-situ, including the method to apply UV epoxy with capillary action.

Attachment 1: beamdump_delamination.png  1.426 MB  | Hide | Hide all
beamdump_delamination.png
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