==== Changing Terminal Energy ==== - Put the Faraday cups in. - Switch OVERVOLTAGE PROTECTION to DISABLE. - Switch the control mode to GVM. - Slowly turn the CONTROL GAIN to zero while watching the grid voltage. If the grid voltage rises above -5 volts, reduce the CHARGING VOLTAGE to keep the grid voltage less than -5 volts, then continue reducing the CONTROL GAIN to zero. - To go to a higher energy move the CORONA PROBE POSITION "OUT" while raising the CHARGING VOLTAGE. **__NEVER__** allow the GRID VOLTAGE to go more negative than -5 VDC during this operation. - To go to a lower energy move the CORONA PROBE POSITION "IN" while lowering the CHARGING VOLTAGE. **__NEVER__** allow the GRID VOLTAGE to go more negative than -5 VDC during this operation. - Set the TERMINAL VOLTAGE Dial to the desired value. The dial is 2 turns per MV (set the dial to twice the GVM you want). You may have to add some upcharge after setting the dial. - Raise the CONTROL GAIN to 2-3 for low current beams, around 5 for high current beams. The system is now controlling in GVM mode. - Make fine adjustments to the TERMINAL VOLTAGE Dial to reach exactly the desired GVM value. - Switch OVERVOLTAGE PROTECTION to ENABLE.