Beam Switch Box (D47)
The easiest way to see why we're not sending beam to MiniBooNE is to pull
up a display of a Main Control Room switch box. This is done by going
to D47 and clicking "Start SA". You'll get:
The elements needed to run MiniBooNE are outlined in purple (the purple outlines do not show up on the display).
The rows of rectangular lights represent switch blocks for individual
Each has 14 physical switches, one at each console in
the Main Control Room, and one software switch.
ALL must be on (green)
to enable a particular beam.
The panel, as shown, would send beam
ONLY to MiniBooNE.
Specifically, you need:
- HEP Permit - the global permit to deliver beam. Unfortunately, this
permit toggles on just before beam is sent, and since this virtual display
samples asynchronously, it will often spuriously read "HEP Inhibit" for
a particular cycle.
Master Switch - All the switches in the master switch block must be on,
which will turn the green "Master" light on and enable beam. This
is needed to enable any sort of beam.
Linac Permit - The permit (interlocks, rad monitors, etc.) to run beam
in the Linac.
Booster Permit - The permit to run beam in the Booster.
The MiniBooNE Beam Permit - Allows us to run beam in our line. See
the "MiniBooNE Beam Permit" section for details.
The MiniBooNE Switch Block- All the switches controlling the MiniBooNE
line must be ON, which will cause the "BooNE" light to come ON.
A couple of subtle points:
Warning! If you leave this display up,
it will eventually time out and stop updating with no indication, so only
bring it up if you suspect something is amiss.
The Booster and Linac do not have to be "ON" to deliver beam to MiniBooNE
or anyone else. The individual controls on these accelerators control
dedicated test beams used for studies.
We do not require a Main Injector beam permit to run beam to MiniBooNE.
The Main Injector elements necessary for MiniBooNE operation are common
to both permits, but there are other things which could block the Main
Injector permit and still allow MiniBooNE to run.