====== Manual Setting of the Magnetic Field ====== ===== Driven Mode ===== Advantage: faster field sweeps. Disadvantage: helium consupmtion and noise increased. - Superconducting switch HEATER ON. Wait 1 minute. - Select right MID set point with SELECT on keypad. - Press MID toggle button. - To change set point to a smaller or bigger value, just change MID set point and re-press MID if not already toggled on. - Note that you can PAUSE the ramp at any moment with PAUSE. ===== Persistent Mode ===== Advantage: less noise and helium consumption, field more stable. Disadvantage: slower to change field. - Superconducting switch HEATER ON. Wait 1 minute. - Energize to desired current/field setpoint (by pre selecting the desired MID setpoint and pressing MID). - Wait about 1 minute for current to stabilize. - Turn OFF superconducting switch HEATER. - Wait 1 minute for switch to become superconducting. - Set current to ZERO, slowly first and at lower current the rate can be increased. - Now you can possibly switch the magnet power supply off. To set the field back to ZERO or to a different value: - Switch HEATER still OFF. - Ramp up the current to previous value and wait till value is reached. - Switch's HEATER ON. Wait 1 minute. - Change set point by changing MID. Press MID (or ZER0). - Wait about 1 minute for current to stabilize. - Turn OFF superconducting switch HEATER. - Wait 1 minute for switch to become superconducting. - Repeat, as written above, the procedure to ramp the current to ZERO and switch off the power supply.