1st day of the experiment week

After a weekend's relax, cryopump is full of gas vapour that was once condensed on the metal plate during pumping process of the previous week. It needs a restart.

1. Restart cryogenic pump

1.0 Get rid of the gas inside of the Cryogenic pump by using roughening pump.

1.0.1. Before doing anything (that one may regret later) make sure that:

• no contact between roughening pump and main chamber
• no contact between roughening pump and outside
• no contact between cryogenic pump and outside.

1.0.2 Connect roughening pump with Cryogenic pump　　make sure that the wire is connected and then turn the switch (that connect crogenic pump and roughening pump) on, there is a mechanic sound to confirm that the corresponding parts (inside) moved.

1.0.3 Turn on the roughening pump.
(It is a little better to turn on the roughening pump before turning on the switch, I feel)

1.1 Start the Cryogenic pump

When the pressure inside Cryogenic pump is about 70~100 mTorr.

1.1.1 Turn off the switch that that connect cryogenic pump and roughening pump, disconnect the wire of the switch from power, and turn off the roughening pump.

1.1.2 Turn on the cooling water for Cryo pump and then turn on the power of the Cryo pump.The temperature inside of Cryo will drop quickly from 293 K to 150 K within an hour (or 30 min, I forgot?).

2 hours later the temperature should stay at 8 K which is the working temperature of Cryo.

If the temperature didn't drop to 8k within 2 hours, the process of starting Cryo failed and one have to know the reason why it failed and prepare to start it the next day (wait a whole day for the condensed gas to vapor so that it's possible to be evacuated by roughening pump). The reason of failure is always that the 1.o process failed so that vacuum inside of Cryo was so bad that temperature can never drop to 8 K (too many gas molecules keep taking heat from the shell of cryo which is about the temperature of outside environment.)