Drift Chamber Operations Manager Duties
Last updated: 16 April 2001, M. Kelsey
[Shift Organization]
[Survival Guide]
[Safety Checklist]
[Contact List]
[Current Problems]
Attention DCH Operations Managers!
This is a summary of your responsibilities as the Drift Chamber
Operations Manager.
Please read this before you start your tour of duty, and
check it periodically for updates.
It's all about common sense, we know, but there are a few things we would
like you to remind yourself. Thank you for your cooperation.
|
General Responsibilities
The DCH Operations Manager is responsible for:
- Ensuring safety and health of the Drift Chamber.
- Helping the BaBar shifters to solve DCH problems.
- Communicating with the BaBar Run Coordinators.
To this goal, you are required to:
- Be available to the BaBar shifters 24 hours a day.
- You represent the single point of contact for the BaBar shifters.
- Carry the DCH pager and the cell phone when you are not in the
control room.
- Make sure the cell phone and pager are operational. If the
batteries are low, change them.
- A spare cell phone battery is in the charging stand at the DCH
workstation.
- Be able to handle all DCH problems.
- It doesn't mean you must fix them by yourself.
- Identify which part is broken.
- Know who is responsible for the broken part
and how to reach him/her.
- Stay up to date with known problems.
- Check on things at IR-2 at least once or twice a day.
- Attend the 3:30 pm IR-2 Operations Meeting (see below).
- Look at the history of currents with strip charts and look
for spikes and for any rise in the baseline current of a channel.
- Ask the BaBar shifters if they noticed anything unusual with the
chamber.
- Check the status of, or run, the
online calibration
- Calibrations are now centralized, just check the output.
- Remind the shift leader if it's been more than 24 hours
since the last calibration.
- If there are problems with the calibration, record them in the logbook.
- Communicate and share information.
-
Controlling the DCH High Voltage
The Drift Chamber HV can be one of the three states:
- On at the nominal working voltage, a.k.a. V1 = 1930V.
- On at the safe voltage, a.k.a. V0 = 800V.
- Off.
The first state may be called ``Runnable'' or ``Unsafe'', the latter two
``Injectable'' or ``Safe''. Normally, the DCH is kept in a "Global Control"
state, where the voltage is raised and lowered automatically when the BaBar
Shift Leader changes the running state of the detector.
A DCH expert need not be present in the control room when the Drift
Chamber is, or may be brought to, ``Unsafe'', unless there are special
conditions. Nevertheless, you are responsible for:
- Protecting the Drift Chamber from potential damage.
- Maximizing the time during which useful data is taken.
- Accumulating the operational experience to establish
a procedure.
It is up to you to find the best balance between the first two conflicting
objectives. Remember that you have been given the authority to decide
whether the DCH can take data or not; if you think it is unsafe, it
is unsafe. If you find, in reviewing the logbook, strip charts, and
run history, that the DCH is experiencing excessive currents, too many
trips, or any other unsafe condition, you have the authority to stop
running.
The third objective is no less important than the first two. You must
write down everything that happened to the DCH HV and the background
condition of the moment on the DCH logbook. Also write down your personal
judgements and ideas for when and how to raise the HV. Our goal is to come
up with a safe and efficient operation procedure that can be documented and
followed by the BaBar shifter.
To achieve the above goals, the person on shift is required to ensure
that:
- The HV is raised only when the background is acceptable.
- Make sure that MCC and BaBar have confirmed ``stable beam'' condition.
- Raise the HV by following
the instruction.
- Monitor the HV current,
event display, and every other information available.
- Lower the HV as soon as there is a sign of excessive background.
- React to HV trips.
Identify the cause.
Assess the damage.
Recover the HV as soon as the condition improves.
- Attempt to maximize the uptime.
- The background is tolerable for the DAQ.
- Monitor the event display.
- Monitor the data size, deadtime, and lost contribution.
- Advise the BaBar shift when the background is too high.
Comments to Michael Kelsey <kelsey@slac.stanford.edu>
|
