Intermittent beam has been back to Hall B since 7h this morning.
As of 12h, nothing usefull has yet started, due to a combination of
classc8 beeing down for a while and frequent and long beam off conditions.
The reason is that they are delivering today polarized beam to Hall C and
need to frequently retune the arcs, loosing thus the tune to hall B.
It is expected that this will happen frequently till they put back the thermoionic
gun tonight, after which it should be much smoother. Today it may well be that
we often will get only pulsed beam.
Given that, after having retuned the beam in Hall B, and measured rates target in
target out (see entry in paper logbook), we will concentrate today on timing studies,
which are not sensitive to bad beam conditions.
Schedule for today:
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*Timing studies MOR-TOF
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a) high current ( 5 nA average on rdiator A)
MOR delay at 2 ns
TOF width: 100ns (dimangui)
few TOF turned on (e.g. counters 1,2,10,11,21,22,31,32,41,42 on sector 1 and 4)
coda configuration: g1_TAGTOF
trigger Tigris: g1_ALLTOF_ASYNC.
Photon trigger: MOR.ST in coincidence
should see only accidentals in TOF TDCs (width should be that set in dimangui)
b) low current (0.3 nA on radiator A)
same TOF turned on
should see the good events in TOF TDC's.
c) low current (0.3 nA on radiator A)
all TOF turned on
take data with different delay settings on MOR delay and TOF width.
MOR delay | TOF width
32ns 120ns
32ns 100ns
32ns 90ns
32ns 80ns
32ns 70ns
32ns 60ns
32ns 50ns (only if not completely out of range)
22ns 50ns
12ns 50ns
2ns 50ns
2ns 60ns
2ns 70ns
take approx 200000 events per run
*Timing studies T-counters
--------------------------
a) E-T coincidence off, TL-TR-E-pres logic set to 2 fold
-trigger MOR.PC, MOR/PC delay set to 30 ns
take 20000 events
-trigger PC
(be sure MOR TDC is in the Raw banks, ROC12, slot 15, channel 16)
take 200000 events
b) E-T coincidence off, TL-TR-E-pres logic set to 1 fold (change downstairs)
- All right T HV off, left T HV on: trigger MOR.PC (20000); trigger PC (20000)
- All left T HV off, right T HV on: trigger MOR.PC (20000); trigger PC (20000)
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Don't forget the 3:00pm meeting.
A g5 representative should be at the meeting.
See you,
Claude MARCHAND.