Thanks for the response,
my research so far (cryogenics journals) has suggested a silicone based adhesive as it may be more forgiving during the cool down.
I have also found the following and will run a few trials:
http://www.masterbond.com/produse/produse_cryo.html
I am searching for a tried and tested adhesive to be used at 77K (and eventually 4.2K). The adherends are optical windows with titanium mounts. The joint should be vacuum leak tight between 77K and 300K (continually cycled).
We currently use a 2 part epoxy mix, Eccobond, which does not...