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run 20466: 
time: 4/27/09, ~21:28-21:42

p_R=1.1759, 
thresholds: -20, -30, -40mV
delays: original, no VETO
Observations: 
  a) PS and SH in 740 completely miss each other by ~40ns (PS too early), PS vs. SH spectrum show rectangular cuts;
  b) PS-DM might be too early than TS-DH by 8-12ns, but can produce electron narrow (single peak in TDC)
  c) electron wide TDC has two peaks.
  d) pion narrow and wide TDCs have two peaks.

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run 20695:
time: 5/3/09, 6:14-6:59
p_R=3.0855
thresholds: -15, -20, -60mV
delays: group 5 has extra 32ns between PS Sum8 and 740;
        group 1-4 have VETOs in;
 	VETO reversed by additional units and fed to fbTDC;
Observations (group 5, no VETO):
  a) TS TDC has only one peak now;
  b) but PS-DM completely miss the TS-DH by ~40 ns (or slightly less), and do not produce electron narrow trigger;
  c) they do form electron wide trigger (single TDC peak); 
  d) TS-DL do form pion narrow and wide triggers (single TDC peak);

VETOs:
  a) GC only signal is missing (hence also from both VETOs). But "coin level" for GC.and.SC was sent to 1 and still have outputs;
  b) GC.and.SC and (.not.GC).and.SC appear to have 100ns delay compare to GC or SC only, suspect mistake in reversing the signal (fed to TDC);

Observations (group 4, with VETO):
  a) TS-DH has two peaks with ~40ns apart;
  b) Pion narrow and wide seem to have full triggers for the 2nd TS-DH peak (2nd in timing), i.e. pion VETO must have arrived before (>) channel 800;
  c) Taking AND of TS-DH and PS-DM should have a single peak starting ~850, (though PS-DM miss the 2nd TS-DH peak). This is not seen in electron narrow trigger, indicating electron VETO is too late, probablly arrived after (<) channel 850;
  d) PS-DM is too early compare to the 1st peak in TS-DH by ~12ns;
  e) electron wide do have triggers, but seems to cut into middle of the 2nd TS-DH peak, indicating VETO arrived near channel 770 or slightly earlier (>770).

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run 20792:
time: 5/5/09 22:07-22:46
p_R=3.0855
thresholds: -15, -20, -120mV
delays: group 5 returned to original
        group 2, 6, 7 have 37ns removed between PS Sum8 and 740;
	group 1-4 have VETOs in

Observations (group 2, with VETO):
  a) TS-DH has only one peak, as expected;
  b) PS-DM is too early compare to the 1st peak in TS-DH by ~12ns;
  c) no electron narrow trigger, indicating electron VETO too late, probablly arrived after (<) channel 850;
  d) no electron wide trigger either, (same conclusion as c)
  e) almost no pion narrow trigger; since TS-DL started probablly around 850, this means pion VETO arrived after 850;
  f) partial pion wide trigger; starting around 785. This means pion VETO arrived around 790.
  g) GC only is later than SC only, by 5-10ns (maybe 8ns is the central value). 

Overall, now electron VETOs arrive near 770, pion VETOs arrive near 790. This seems to be understandable if GC arrives late than SC by 8-10ns.

If delay SC by 10ns, may decrease the difference between e and pi VETOs. Both would arrive at the current pion VETO time, i.e. 790.

Overall, should delay:
  SH Sum8-740 by original + 50 - 32 ns = 16ns
  PS Sum8-740 by original + 50  =  50ns
  PS Sum8-DM by original + 50 + 12 = 62ns
  SC by 12ns, (or swap cables of GC and SC which are supposed to be 37 and 32ns, respectively. To be sure, will still add additional 4-8ns to SC after swapping).

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run 20889: 
Eb=2.425, p0=2.1813

doesn't seem to be a good run, had 2nd peaks at (850,1000) for all preshower, shower, and electron triggers, but not on pion triggers.

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run 20928: "Golden" polarized 3He run
Eb=2.425, p0=2.1813

Delay conditions:
  between 5/8 and 5/11-12 access
  SC by 16ns
  group 3:
  SH Sum8-740 by original +  0ns
  PS Sum8-740 by original + 32ns
  PS Sum8-DM by original +  48ns
  group 4:
  SH Sum8-740 by original + 16ns
  PS Sum8-740 by original + 48ns
  PS Sum8-DM by original +  60ns

  group 1-4 have VETOs in.

Observations (group 4, with VETO):
  a) Group 4 seems to be working now;
  b) There is a huge peak (10^5) at channel 600 in (.not.GC).and.(SC) - pion VETO, that is not explained by the original GC or SC signals. SC(T1) does not show peak of the same amplitude at 600 at all.  
  c) Suspect something fishy with the way  (.not.GC).and.(SC) is formed now: GC is sent to 755 4th quad VETO in and SC is sent to its input, with coin level = 1. During 5/12 access this is changed to: .not.GC sent to input 2 of this quad, with VETO in left open, and coin level changed to 2. Scope check with a pulser did not find any difference between these two cases: When the pulser is sent to both GC and SC (with delay such that SC is later than GC by 10ns), neither produces a pion VETO.
  

Observations (group3, with VETO):
  a) Cut on Preshower and Shower are working, but they seem to miss VETO a bit for electrons. The electron narrow trigger has much less yield than it should be. Electron wide is okay;


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run 21080: 

  found PS block 14 ([13]) is missing signal. Corrected (bad cable from the PMT) on 5/14.

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run 21137: "Golden" polarized 3He run
  between 5/14 and 5/18 access

Eb=2.425, p0=2.25, theta=16

  Compare to 20928, now all groups have the same delay as gr4. 
  Group 1: Shower slightly ahead of PS, Electron narrow have cutoff from VETO, causing loss of high SH events.
  Group 2: Shower slightly ahead of PS, Electron narrow have cutoff from VETO, causing loss of high SH events.
  Group 3: Shower slightly ahead of PS, Electron narrow have cutoff from VETO, causing loss of high SH events.
  Group 4: Shower behind PS significantly (big bump), but PS vs. SH looks decent, no cutoff from VETO, might be the only group working properly;
  Group 5-8: PS and SH alignment when forming the TS seem to be much better than Gr1-4. Can almost call TS TDC to be "narrow peak".

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 5/18 access: 
   Adjust timing of gr1-4;
   gr5 has extra delays in TSDH and PSDM output (before forming electron triggers, this is to test if can avoid VETO cutoff);
   gr5-8 has tagger in TS, PS (adding extra 740), both have 10-16ns extra delay because of the extra 740. But tagger has T1 in (mistake).

Next step:
----------

a) Add delays following group 4(run 20928) to all other groups:

  SH Sum8-740 by original + 16ns
  PS Sum8-740 by original + 48ns
  PS Sum8-DM by original +  60ns

b) Add VETOs to group 5-8.

Both were done during the 5/12 access.

History of changes and accesses can be found at:

http://www.jlab.org/~rsubedi/PVDIS/document/present_status.txt