Report on Interlocks Meeting

Prepared by Pierre Bricault, meeting held Apr. 3, 2003

Invited: Paul Schmor, Miguel Olivo, Andy Hurst, Rick Baartman, Marik Dombsky, Rolf Keitel, Guy Stanford, Don Dale, Mike McDonald.

Present: Pierre Bricault, Miguel Olivo, Andy Hurst, Marik Dombsky, Rolf Keitel, Don Dale, Mike McDonald.

Absent: Paul Schmor, Rick Baartman, Guy Stanford.

Agenda:

1. ITE interlocks,
   1. Target interlocks, ITE:TGHT and ITE:TBHT => cooldown sequence
      1. Water flow in the chase
      2. Water flow elsewhere
   2. ECR coils interlocks => cooldown sequence
      1. Water flow in the chase
      2. Water flow elsewhere
   3. Beam current interlocks
      1. What device do we turn off?
      2. Current limit?
      3. Software limits? Who can change the limits?
   4. AOB
2. ITW chase conductors.
   1. Should they be in the interlocks chain or leave it in the PLC?

1. a,b) ITE interlocks: Target interlocks and ECR coils

According to Mike McDonald, the interlocks [for] if the water flow goes off in the target module were checked last fall, and they are working.

According to Miguel's calculation, the chase conductors (5kG in weight), running 1000 Ampères, will reach 100°C  after ten minutes. The chase has no air flowing into it. The chase water flow interlock should be changed. The following actions should be taken if the water goes off:

1.  Wait 30 seconds to avoid false reading.
2. Raise an alarm in the control room.
3. Turn off [the] HV bias.
4. Turn off [the] extraction electrode voltage.
5. Start TGHT and TBHT cooldown, from actual value to zero Ampère in 15 minutes.
6. Turn ECR coil power supply off.

1. c) Beam current interlocks
   1. What device do we turn off?
   2. Current limit?
   3. Software limits? Who can change the limits?
   1. A warning will be raised if the skimmers have more than 10 µA.
      1. After 5 minutes, if the warning is not removed, the following chain of actions will occur, then
         1. Extraction electrode voltage sets to 0 Volt.
      2. After 15 minutes, with the EE set to 0 V, [if] the warning is not resolved, then
         1. High Voltage Bias turns off.
         2. Extraction Electrode turns off.
   2. A trip level is set at 20 µA.
      1. High Voltage Bias turns off.
      2. Extraction Electrode turns off.

The limit will be a software limit. The skimmer current will come from the IOC and a communication link goes to the PLC. A watchdog has to be installed to monitor the communication link. If the communication stops, the following actions take place:

1. High Voltage Bias turns off.
2. Extraction Electrode turns off.

Since the current is read from the QSX, the gain on the skimmer reading has to be fixed.

[Action item: Pierre to raise an Eng. Change Request (ECR) in order to implement those changes into the actual interlocks system.]

[Action item: Mike McDonald to tell Rolf Keitel which of the two flow switches do[es] the ECR conductors cooling, and which one do[es] the TGHT and TBHT.]

Since the time is quite short before the scheduled ECR operation, priority should be given to the beam current interlocks (item 1.c.).

The procedure to change the current limit was discussed. We agreed that this modification could only be done through a proper Engineering Change Request. For the time being, the warning limit will be 10 µA, and the trip limit at 20 µA.

2) We agreed that the chase's conductor interlock could stay like it is now. However, we should have a display in the control window for the Operations Group to easily visualize the status.

[ed.: See skimmers interlock chain diagram on the ION entry for this item.]