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Message ID: 25     Entry time: Wednesday, August 24, 2011, 17:11
Author: Bevan Moss 
Category: Conditioning Station 
Type: Standard Operation 
Module: TM1 
Target/Number: UCx#2 
Subject: Leak Check, HV conditioning and Module Move 

Today a leak check on TM1's external seals and the heat shield line was completed by David Wang. After 16 hours of the turbo pumps running on the conditioning station stations pressures were 3.6 x 10^-6 T, 1.2 x 10^-5 T, and 1.8 x 10^-6 T for the containment box, secondary vacuum, and service cap respectively. This is a significantly quicker pump down after the cross with small turbo pump was installed on the vacuum vessel. The base pressure of the leak testing cart was 0.0 x 10^-4 T and the leak rate was 1.2 x 10 x 10^-8 atm cc / sec. There was no response from the external test where the module was sprayed with helium. The heat shield line was pressurized with 80 psi helium which caused the leak rate to climb to a maximum of 2.5 10 ^-8 atm cc / sec but dropped to 1.9 x 10^-8 atm cc / sec and was stable there, the total test time was 2 minutes. This test was repeated another time and had similar results.  These results although showing a slight increase in the detected leak rate are withing acceptable and indicate that the module is leak tight. 

At 9:30 the HV check and conditioning started (~17 hours turbos on), the secondary vacuum, containment box and service cap had the following pressures in Torr respectively, 1.0 x 10^-5, 3.2 x 10^-6, 1.6 x 10^-6.  The voltage was steadily raised with virtually no current up to 28.5 kV which was achieved at 9:50. When raised to 30 kV the current increased significantly to ~300 uA and a large amount of sparking occurred. The voltage was dropped to 0 volts for 2 minutes and then was returned to 30 kV at 10:03, the current draw was around 200 uA and climbing. After a few sparks and time the current had dropped to 120 uA. This indicates that the module is still conditioning and matches what is observed by the control room when the module is in ITW. The module was deemed acceptable for this current run and was then vented with argon this took about 2 hours.

The module was then remotely moved from the conditioning station to ITW. When first attempting to transfer the controls to the remote control room they were not transferred and when testing the up command as per standard procedure the module dropped down slightly. David Wang went to lock out the target again and the controls were successfully transferred. A note of this was made in the log book. Apart from this the move went smoothly.  

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