Short Term Run Plan - 30 September 2002 (Monday)

B2 VISUAL SCALER SCAN

TURN OFF the chamber high voltages.  Then, from Epics, open all the
slits and jaws wide open (yes, including F1).  (The way I usually do
this is to pick some largish number, say 120 mm, and see what
happens.  If epics rejects that number, it's too big, so try a smaller
number.  Watch the little graph -- the black bits represent how wide
the slits/jaws are.  At full width the green bits will still be there
a bit, but it'll be close enough.

Tune to 29.6 MeV/c.  Set the scalers to count for, say, 10 seconds.
Let them count for one cycle each, and flip the scalers to manual (it
isn't labelled like that; the switch on the "gate" section of the box
goes down for manual, up for automatic).  That way it stops counting
and you have time to write down all the scalers.  Record the
following:

B2 NMR reading
ION
M
MLT
PU
DS

We're most interested in M, but the others are of interest, too.  The
ION count is proportional to the proton current, so it's used as a
normalization.

Change B2 down by something like 10 Gauss or so (around 20 DAC units,
I think), wait for the NMR readings to stop changing, and write
everything down again.  Keep doing this until M/ION decreases
"significantly".  (Use your judgement, I guess.  And if ION isn't
changing much, you can just go by M.)  Then go back to "nominal"
(making sure to match B2NMR to what you started with) and do the same
in the other direction.

Finally, go back and fill in (1 Gauss steps or so) around the "peak"
of M/ION.  (Do this over a range of about 20 Gauss each way.)

Please paste a table of these numbers into elog.  (emacs or another
text editor is a nice place to make the table.)

If you're bored later, you can make a plot of (M/ION) vs B2NMR and
post it...



SURFACE MUON STOPPING DISTRIBUTION STUDY

You want 29.6 MeV/c, with the M trigger.  The nominal settings should
give you a rate of about 2 kHz on M.

Set the gas degrader to 55% He, and give it about 30 minutes to flush.
Take 6 runs (ie. about 6 million events).  (This should probably take
about an hour.)

Do this again for gas degrader settings in 5% He increments up to 85%
He, waiting 30 minutes after each change and taking 6 runs each.

As always, please make an elog note as to which runs correspond to
which gas degrader settings; it's just more convenient to work with later.



DATA AT NOMINAL STOPPING LOCATION

Once we know what gas degrader settings gives us the most centred muon
stopping distribution (by comparison with Geant predictions using the
"restricted last Z for muon" histograms) we'll want to take 2 days
worth of data at 2 kHz at that degrader setting.  This works out to
about 346 million events (2000*3600*48).