5 hrs data taking, retime check, beam in-stabilities. Porgram for rest
of night.
_ Had problems with camac BHWY. Eventually swapped crate controller #2
with spare module
_ 9:00 Beam on, field on at 3500 A and took data until ca. 2 pm
Background rate on empty target were good. However rate with gas on
was quite unpredictable at high currents (50 mA) on a fill-by-fill basis
_ injection on empty: 60 mA, injection with gas 35 mA
_ Done few tests, definitely injection with gas off worsen the situation.
Instaneous rates up to 60 kHz (coincs) for very small lifetime (2 min)
Then lifetime would go up, rate gets' better
_ Suspect ion effects in the ring. Played a bit with LIC1, found
favourable setting at 2300
_ Accelerator down due a water leak, few quad and a dipole down. Water
leaks into SH. Beam comes back and we get 50 mA at injection with gas
and field on !
_ Rate instabiliy still there at high currents
_ Done a true retime check with flasher. Unfortunately method does not
seem very precise possibly due to large variation of analog in from
flasher (different in all channels) beyond range of CFd (note, flasher
pulse can range from few 100's mV, to 4-5 Volts)
_ Analysis: L/R asymmetry still there. Trigger time ?
** PROGRAM for tonight: *******************
we continue field on data taking, one spill at a time. Will take
data without common strobe mode. Then 2-3 hrs of field off data (to check
adc spectra).
**************************************************
________________________________________________________________________________
Tancredi Botto, phone: +1-617-253-9204 fax: +1-617-253-9599
research scientist MIT/Bates, 21 Manning Av Middleton MA, 01949
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This archive was generated by hypermail 2.1.2 : Mon Feb 24 2014 - 14:07:28 EST