Power-up Procedure

1.

Ensure gas flow has been established in the chambers as previously outlined. If it has not, STOP RIGHT HERE! Gas flow must be well-established and steady-state BEFORE the HV may be enabled.

2.

Ensure that all power supplies as well as the FASTBUS crate are off and then connect the LV, HV, and TDC cables.

3.

Enable the LV. Set points are clearly labeled on the face of the power supplies. Note that they have overcurrent setpoints, and some fine adjustments over the first 30 minutes after a cold start power-up may be required. Appropriate LEDs should all be active on both the power supplies and the pre-amp/discriminator cards.

4.

Slowly (steps of no more than -100 V) ramp the HV to its nominal set point of -4.00 kV using either the manual or the remote controls. While the trip current is set to 10 A, do not allow the chambers to draw more than 1 A during the ramping procedure or serious damage may result. If the power supply trips during the ramping procedure, you are moving too fast. Rezero things and begin the procedure again. NEVER USE THE AUTO-RESET FUNCTION. If the power supply trips again, STOP IMMEDIATELY AND INVESTIGATE.

5.

Enable the FASTBUS crate. Appropriate LEDs should all be active.

6.

Check for poor signal connections evidenced by hot wires (wires counting extremely fast) or dead wires (wires with no counts) using the histograming software and cosmic rays. Remake any connections as necessary by first powering down the FASTBUS crate.

If at all possible, the HV and LV power supplies should be left on continuously if and only if gas is available to the chamber. This avoids time loss to reconditioning and maintains the desirable steady-state operating condition.