Subject: Raith shutdown:T motor and loadlock valve errors
From: Jesse Lu <>
Date: Thu, 13 Aug 2009 11:04:02 -0700 (PDT)

Cannot successfully load or unload because the T motor cannot find its limits. Also,
loadlock valve cannot be closed. Repeated attempts to load have all failed. Do not use
the Raith.

This problem has come up in the past; however, after not being able to find inner/outer
position, the loadlock valve will not close. This is critical, because an open loadlock
valve will cause the turbopump to overheat and fail.

I contacted Dr. Joseph Klingfus at Raith and he led me through an involved procedure
to manually close the loadlock. I had to open the backpanel on the Raith equipment rack
and have left it open temporarily for convenience.
Otherwise, vacuum levels seem normal. System is 1e-6 and Gun vacuum is 1e-9.

Jesse Lu