E949 Online Photon Veto

The online PV scheme is quite different between E787 and E949.

• E787: analog-sum
  1. Endcap [ECL0 == EXT_CON(5) in tr2bits.cmn, true if energy observed]
     - OR of the CFD outputs from each counter
     - threshold 30mV for Ring1 counters, 24mV for others
  2. Range Stack [HEXCUT == Hex_Cut in tr2bits.cmn, false if energy observed]:
     - Look-up table in the TT2A board checks the CT-unrelated visible energy with the Hextant 1 .. 6 bits
     
     • Hextant bit [HIT_HEX(1 --> 6) in tr2bits.cmn]
       - Analog-sum of the upstream and downstream PMT outputs of the RS laysers/sectors in the same hextant
       - threshold 500mv for each hextant
  3. Barrel Veto [BVL0 == EXT_CON(4) in tr2bits.cmn, true if energy observed]
     - Analog-sum of the upstream and downstream PMT outputs of the BV laysers/sectors
     - threshold 150mv
  4. ( no Barrel Veto Liner in E787 )
     • In the early stage of E949, we setup and used the BVL analog sum:
       - Analog-sum of the upstream and downstream PMT outputs of the BVL sectors
       - threshold 200mv
• E949: meantimer
  1. Endcap [ECL0 == EXT_CON(5) in tr2bits.cmn, true if energy observed]: no change from E787
     - OR of the CFD outputs from each counter
     - threshold 30mV for Ring1 counters, 24mV for others
  2. Range Stack [HEXCUT == Hex_Cut in tr2bits.cmn, false if energy observed]:
     - Look-up table in the TT2A board checks the CT-unrelated visible energy with the Hextant 1 .. 6 bits: no change from E787
     
     • Hextant bit [HIT_HEX(1 --> 6) in tr2bits.cmn]
       - OR of the Meantimer outputs of the RS layers (from 2 to 19) in the same hextant
       - The upstream PMT outputs of the four sectors in the same hextant and the downstream PMT outputs of the four sectors in the same hextant are summed up, separetely, and the upstream and downstream signals are fed into a Meantimer board, in which the signals are discriminated and then mean-timed.
       - threshold 50mv (the run 49172, Apr 30 and after) for a Meantimer input (single end)
  3. Barrel Veto [BVL0 == EXT_CON(4) in tr2bits.cmn, true if energy observed]
     - OR of the Meantimer outputs
     - The upstream PMT outputs of the two adjacent sectors and four layers and the downstream PMT outputs of the two adjacent sectors and four layers are summed up, separately, and the upstream and downstream signals are fed into a Meantimer board, in which the signals are discriminated and then mean-timed.
     - threshold 30mv (the run 48006, Mar 17 and after) for a Meantimer input (single end)
  4. Barrel Veto Liner [BVLL0 == EXT_CON(6) in tr2bits.cmn, true if energy observed]
     - OR of the Meantimer outputs
     - The upstream PMT outputs of the two adjacent sectors and the downstream PMT outputs of the two adjacent sectors are summed up, separately, and the upstream and downstream signals are fed into a Meantimer board, in which the signals are discriminated and then mean-timed.
     - threshold 30mv (the run 48006, Mar 17 and after) for a Meantimer input (single end)
  5. The Hextant, BV and BVL bits by analog-sum signals (see above) are fed into the External Conditions for Trigger Transmitter (but UNused in the trigger conditions); see this page.