Good luck !
Runplan 11-01-02 - tb
=================
Priority is on the Cerenkov. Tavi is in charge and will start internal
Cerenkov gain matching. He has highest priority Friday night and from
Saturday at noon. He will work in the D-tunnel with flasher ON and the
scope. In principle you can negotiate beam on when he is in the d-tunnel
(since he'll use the flasher as trigger)
We have a first wrap of mu-metal shield around the TOF pmts.
Sunday evening the beam goes back to CCR for development of snake on/field
on tune.
Friday - Eve
=============
Tavi will work on flasher. After that take two cosmic runs with field
on and off. Monitor and log the TOF rates and analyze ADC spectra. Make
conclusions about effectivness of added shielding.
After that we need the power supply OFF. Remind CCR that, so they can turn
off the magnet cooling (IMPORTANT)
Save the phase1/cc_eff.C and phase1/tof_eff.C to cc_eff_paddles
(tof_eff_paddles). We need an automatic cc_eff.C for beam runs, starting
from the eep ntuple (or TBlcut)
You should repeat the analysis of last night: e.g. for L0 I used the
following cut (from eep)
(ntr<14&&ntr>12&&ncr==-1)&&(ntl==1||ntl==2) && (atr>4000)
and varied the right sector (proton) ADC cut. Note enforce no cerenkov on
right sector. However, we should definitely add a TDC cut to select
the center portion of the TOF, Cerenkov
We should then extend this code for other cerenkovs
Saturday - Night
=================
Start eep elastic data taking with field off. Accumulate statistic for
in depth L/R asymmetry study.
Analysis should use show_proton.C in phase2 (pedestal subtracted) or
show_ptof.C in phase1 (not subtracted). That macro has the option
of selecting individual TDC-diff cuts, rather than only using an ADC
cut. Note, Cerenkov cuts may introduce asymmetries
Saturday Day
===============
Keep running. Tavi will finish gain matching with scope.
After CC gain matching (has priority) we have starting HVs for a
cerenkov efficiency study. *Shoud the separation between pedestal
and peak be not too clear, scale all voltages in that box by a fixed
amount*. Be aware (and tune against) DC offset from the CC fifo.
Saturday Evening - Sunday Evening
=================================
Here the goal is to take runs at fixed CC voltage and as a function of
threshold (currently at a minimum 25 mV). After gain matching of course.
It takes < 1 hr running to analyize the front 2 cerenkovs. It takes
longer for the other two. So it may be more efficient to scan the
thresholds of the front for fixed threhsold in the back (so that you can
re-analize the same runs and have higher statistic in the back)
I would not expect the cerenkov to be really 100 % efficient. Part of the
"efficiency" may come from noise CC-triggers, especially if the given box
counts well above 100 KHz. Raising threshold may then lower the "efficiency"
but give a more realistic reading. Increasing threshold will bring over the
1 photoelectron peak and so on.
If N is the photo-electron, and the threshold is belowe the 1 PE peak,
the CC eff is ( 1-exp(-N) )
if the threshold is above the 1 PE threshold the CC eff is
(1 - (1+ N)* exp(-N) ) and so on
Sunday Evening the beam goes to CCR
============
I am reachable tomorrow at home, unreachable on sunday
-tancredi
-- ________________________________________________________________________________ Tancredi Botto, phone: +1-617-253-9204 mobile: +1-978-490-4124 research scientist MIT/Bates, 21 Manning Av Middleton MA, 01949 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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