I am using a new system of molecular beam epitaxy (COMPACT 21). the pressure of the growth chamber was 10^-10 torr. suddenly, we found it a round 10^-7 torr. This increase in the pressure happened after trying to calibrate the temperature of the Ga source. The tip temperature was 500 degrees and the base was 450 degrees. the next day the thermocouple of the tip wasn't reading correctly like damaged. Also, the pressure of the growth chamber increased from 10^-10 torr to 10^-7 torr.
Can you explain the reason for damaging the thermocouple of the tip and the increase in the pressure of the growth chamber?
Thanks in advance.