Notes on EDTM Setup for E08-008/E08-010

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User name V. Sulkosky

Log entry time 00:10:28 on February 11, 2011

Entry number 346338

This entry is a followup to: 346329

Followups:

keyword=Notes on EDTM Setup for E08-008/E08-010

Notes from EDTM measurements/calculations.

In the BigBite weldment:

218 ns   Internal delay from the EDTM Master
 18 ns   Cable/module delay to discriminator
------
236 ns

Measured time from BB EDTM Master Back to LHRS Scintillator input:


  8 ns       Lemo to level translator
  6 ns       Internal delay level translator
 24 ns       ribbon cable + 4518 internal delay + level translator
  7 ns       Lemo to LHRS patch panel on weldment
260 ns       RG58 to LHRS hut
  8 ns       extension cable to patch panel on LHRS
  4 ns       Lemo to FI/FO
  5 ns       Internal FI/FO delay
 16 ns       Lemo to EDTM Slave
155 ns       Internal EDTM delay 
----
493 ns       at S1 EDTM injection point

Measured time from BB EDTM Master Back to RHRS Scintillator input:


  8 ns       Lemo to level translator
  6 ns       Internal delay level translator
  7 ns       Internal delay level translator + 1ns cable
 30 ns       ribbon cable + 4518 internal delay + level translator
  8 ns       Lemo to RHRS patch panel on weldment
192 ns       RG8 to RHRS hut
  4 ns       Lemo to FI/FO
  5 ns       Internal FI/FO delay
 16 ns       Lemo to EDTM Slave
170 ns       Internal EDTM delay 
----
446 ns       at S1 EDTM injection point

Time difference between EDTM pulses without adjustment:

On the left HRS, the S2m EDTM "OR" comes 48 ns after S1 EDTM "OR".
On the right HRS, the S2m EDTM "OR' comes 24 ns after S1 EDTM "OR".
Accounting for time differences due to S2m:

The actual measured delay between EDTM T1 and T3 at the weldment = 94 ns -> RDELAY
---------------------------------------------------------------------------------------------------------------

Times to get from target to point at which EDTM is injected

Proton into L-HRS


    0.450    0.535     0.670  GeV
   ------------------------------
   Proton   Proton     Proton
    200      175       150     TOF
     60       60        60     Signal cable from PMT
    ---      ---       ---
    260      235       210

Electron into R-HRS


 87       TOF
 60       Signal cable from PMT
---
147 ns

Time difference between proton and electron signals to EDTM injection point:


      0.450    0.535     0.670  GeV
      ------------------------------
L-B = 113       88        63

The first setting is the production setting for D-threshold, the second
is the slowest proton for N-Delta and the third the fastest proton for N-Delta.

EDTM script to set this up:

   ~atrig/edtm/edtmsetup [LHRS_DELAY] [RHRS_DELAY]

So... for simulating a 0.450 GeV proton in coincidence with a R-HRS electron:

    edtmsetup 112 94

This setup produces a time difference between T1 and T3 = 126 ns with T1
coming first. This is very close the 113 ns TOF difference expected during
the production kinematics for D-threshold. The width of T3 was adjusted
to be 140 ns and T1 to be 50 ns. As a conservative estimate, I adjusted the
T1 delay on the LeCroy 4518 module to come about 50 ns after T3, which
requires T1 to be delayed by about 170 ns. This was accomplished by
delaying T1 on channel 0 by 128 ns and 3 by 40 ns. I will write a script to
automatically handle the experimental delay changes per kinematic setting.