DDFPD_LM

TDC

TDC

TDC

VTX

8 68

1 D2

TDC Details:• 3 TDC boards for FPD compared to 6 LM boards• 1 board consists of Px1, and Ax1 where x=Up,Down, In, Out pots (first quadrupole castle on either side of IP)• 2 board consists of Px2, and Ax2 (second quadrupole castle)• 2 dipoles + 4 veto counter signals• Allowed 80 bits from each side to vertex board• Each board should set bits at two times, corresponding to in-time hits (time of flight from IP) and to early-time hits from halo (time of flight from IP earlier than interaction)• For each TDC give in-time bit 0 or 1; 16 (6) bits• For each TDC give halo bit 0 or 1; 16 (6) bits• TOTAL 32(12) bits

+V

DDMore TDC Details1 board should send 8 in-time and 8 halo bits to 2 boardwhich should receive these bits and send 16 in-time bits and 16halo bits to vertex boardD+V board should send 6 in-time and 6 early-time hits toVertex boardNote: cable lengths should be such that all 1 signals arriveat 1 board at a fixed time, and all 2 signals arrive at 2 boardat a different fixed time, and D+V signals arrive at a 3rd

fixed time. Carlos should verify these times.

Steps to operational FPD TDC boards1) Brendan finishes TDC firmware2) Carlos ensures that signals arrive correctly at TDC boards along with Victor determines delays for in-time and halo for each TDC board3) Victor finishes database that can download parameters to TDC board—do any of these differ from LM paramaters other than nclock delay and delta delay? How do we determine other parameters (Brendan?)4) Need to have VXWORKS project to modify power PC controls—what exactly has to be done (Brendan, Victor) Carlos should start giving documentation to PhD student and hopefully 2nd Manchester engineer.5) Dave’s work (see later slide)

DDVertex Details

Vertex board should receive 22 in-time bits and 22 halobits from TDC boards. It should form 4 bit words foreach of the 9 spectrometers 0=no coincidence of 1+2 pots for that spectrometer1=coincidence of 1+2 pots for that spectrometer2=coincidence but either one of diagonally opposite spectrometer pots has halo bit set3=coincidence but both of diag opposite pots has halo bit set

Example: PU1.PU2 no early time hits in AD1 or AD2 =1PI1.PI2 with early time hits in AO1 and AO2 =3

Vertex board passes information to TMCan pass up to 96 bits to TM in 16 bit bursts (separated by 18 nsec), 80 bits are currently needed1 Spec 1-4 4bit words2 Spec 5-8 4 bit words3 Spec 9 4 bit word, 2 in-time bits from spec. 9, 2 halo bits from spec. 9, 4 veto counter in-time, 4 VC halo bits4 16 in-time bits from spec 1-85 16 halo bits from spec 1-8

DDDave’s work

1) Get Verilog code to compile, understand TDC board thoroughly2) Add scalar information from each channel, both in-time and early, get this information into EPICS3) Pass information from TDC boards to Vertex boards4) Program Vertex boards

DDTrigger Manager Inputs

FPD_LM1x96

3x96

1x96

FPD_DFE

TMLM

1) FPD_LM 80 bits of information on 9 spectrometers and veto counters—see previous slide, 2) LM TL 8 bits (50 psec resolution) TR 8 bits Fast Z 6 Bits

#N counters 5 bits #S counters 5 bits 16 LM and/or terms 3) DFE 12 bits/track for up to 7 tracks (need format from Ricardo)

DDReal Steps to Triggering

1) Don’t trigger, just readout all events2) And/or terms from SCR:Diff_x (x=PU,… 5 in all) Diff_any, Elas_x (2), Elas (1), DPOM ( up_up, dn_dn, dipole_up, dipole_dn,any): bypass TM3) Add DFE to TM (with no LM or FPD_LM). First

use multiplicity cut to reject halo sprays. Estimated rejection? Expect at least 10.

4) Add trigger equations, this will rule out invalid combinations, allow selection of high-t. Reduce MI background. Estimated rejection? 5) Add L2 Gap tool, L3 tools6) If LM TDC boards are ready, but no vertex board, can we send signals to TM? Replace functionality of vertex board in TM? 7) Once vertex board works, can apply single

interaction algorithm.8) Add in FPD_LM information and disable SCR

and/or terms

DDTrigger Manager Logic

1) Set and/or terms

2) For each track, check that spectrometer word =1 (in-time coincidence, no halo)2) Compare ,t with trigger list and set and/or terms

DDFPD Triggers

16 AND-OR terms allocated to implement allFPD triggers (13 currently in use)

• The FPD Trigger Manager allows cuts on =1-p/p and t, and also incorporates information from the trigger scintillator via the LM boards.• A track is defined as two detector hits in any spectrometer with a valid x and t, a trigger scint. confirm, and no halo veto set.

AND-OR term definitions:

RTK = track in any spectrometer, (D= veto on halo) RPT = proton track RAT = anti-proton trackRTK(1) x > 0.99, all tRTK(2) 0.99 > x > 0.9 all tRTK(3) x > 0.9 all t, no halo vetoRTK(4) x > 0.9, |t|>1 GeV2

RTK(5) x > 0.9, all tREL = Elastic (diagonally opposite p and )ROV = Overconstrained track (D+Q proton tracks) REL(1) = x > 0.99, all t REL(2) = x > 0.99, |t | > 1 GeV2

ROV(1) = x > 0.90, all t ROV(2) = x > 0.90, |t | > 1 GeV2)

LMO = no hits in LM; LMI(1) = Single Interaction;LMD=N+Sbar .OR. S+Nbar

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