Procedures of Switching off HIM
1) ET detector: Power Down; Flood Gun: Power Down
2) Ramp Down the lens 2.
Ramp down the lens 2 slowly, the leakage current should be less than 1uA.
When it is less than 1 kV, we can disable the lens 2.
3) Put the "GFIS" in the Standby Mode (*Never Up GFIS in the Operation Center)
4) Switch off the valve between the chamber and gun system from the Vaccum Dashboard