Triggertiming relative to the the time of the beam crossing S2. The 1994 times are taken from notebooks 2 and 3 of the 1994 data run. See notebook 3 for the 1995 times.
The zero time is defined as the time of the beam crossing the beam counter S2. The cable from S2 to the patch panel is RG62 (93 ohm), 24 feet long. This produces a delay of 29 ns. The transit time in the photomultiplier is estimated to be 30 ns, therefore, patch panel time = 60 ns in this system.
The S2 patch panel is in rack 4; the discriminator is located at 8-1-7-4 (rack-crate-unit-subunit) 18 ns away. The discriminator output is at 85 ns.
signal time (ns)
5/3/94 data 1/8/95 2/4/95
7/12/94
beam crosses S2 0 0
S2 at FT rack 4 panel 60 60
S2 out of disc(8-1-7-4) --- 85
pretrigger at panel 240
pretrigger fanout 280 280 280
upstream beam pretrig
at pretrig fanout --- 280
beam pwc input to
to stobe fanout 300 300 295/300
at pwc A4 input 325
tpx1 gate 470 470 460
tpx2 gate 477 476 460
tpx3 gate 493 496 470
TCYL>0 pulse 585-715
TCYL=1 pulse 605-720 614-680-764
delta_t level 680
strobe TPX mlu 690 695 730
CPVB pulse 770 775 w60
CPVC pulse 770 770 w60
DEA pulse 770 775
S0 pulse 770
strobe level_1 790 790 800
clockstop at MDM 825 825 825
strobe 4508 prescale
outpt of 429 7-1-11-2 890 890 920
level_1 out at spy 855
lev_1 429 out 7-3-9 940 940 950
lev_1 disc out 7-3-12-1 980 980 1000
beam.dt disc output 245
level_2 strobe 10 us
tdc stop 11.78 us
1995 level_2
The level 2 timing is derived from the LGD mam done signal which comes at varying
times depending on the complexity of the LGD data -- typically between 8 and 16
micoseconds after beam crosses S2.
mam done disc out (8-1-7-1) define as t=0
mam done to lev_2 4508 clear 7-5-12-2 30 ns
mam done strobe to lev_2 mlu's 7-4-7 35
mam_dly_150 out 7-5-2-3 210
lev_2A/B charged OR output 8-1-7-1 250
lev_2A/B trigs to 4616 7-5-3 250 (w100)
lev_2A/B strecher out 275 (w400)
lev_2A/B 4508 strb (mam dly 150)7-4-21 280 (w100)
mam_dly_300 out (7-5-7-1) 435
//end file