From:	SMTP%"MINIMAX@FNMINT.FNAL.GOV" 15-JUN-1995 00:40:49.92
To:	MINIMAX
CC:	
Subj:	upstream counters: summary

Date: Thu, 15 Jun 1995 0:38:23 -0500 (CDT)
From: MINIMAX@FNMINT.FNAL.GOV
To:   t864-l@fnmini.fnal.gov
Message-Id: <950615003823.433@FNMINT.FNAL.GOV>
Subject: upstream counters: summary


As of this writing, there are 13 upstream counters installed,
and all of them are reading out successfully. This note is
meant to summarize the information needed for first-round 
data analysis. The counters naturally divide themselves into 
four groups. The kicker counters K1, K2, K3, K4 are located 
55-60 m away from C0 and have been called previously BV1,2 
and BH1,2--or the B48 counters. (They are VPI; formerly used in the
p counter array.) The old nomenclature became increasingly	
cumbersome and it is hoped that this will be slightly simpler.
Note that K3 and K4 are 5 meters closer to C0 than K1 and K2;
K3 and K4 are also buried amidst much material (kicker electrodes),
while K1 and K2 are more in the open. Therefore	their responses
can be expected to differ--this is what is in fact seen.
The second group, the most important, are pbarcal and nbarcal,
also labeled L4 and L6. The third group are the three small 
counters L1 (tiny counter T), L2 (needle counter), and A (or 
sometimes L3). These are lined up along the estimated path of
the 450 GeV pbars, with the ordering L2, L1, Pbarcal, A (L2 is
nearest to C0.) The last group are the other four VPI p counters.
In yesterday's access we stacked concrete blocks on corridor and
wall sides of the hcals to slightly higher than beam-pipe height,
and then laid a plate of aluminum across, above the TeV pipe,
upon which we laid the four counters, with axes parallel to the
TeV beam. The 2 x 2 blocks were centered directly above the
TeV pipe, and the 2 x 4 blocks were put furthest out. Seen from
C0 the configuration is as shown below:

             ___________________________________
             |          |     |     |          |
             |   L9     | L8  | L7  |   L5     |
             -----------------------------------   

                  
                Pbarcal       |        Nbarcal
                            --+--
                              |TeV pipe

A 1X0 layer of Pb was placed in front of the faces of these
counters. The idea is to use these in quasi-veto mode; when
a full-energy pbar or nbar goes into an hcal, perhaps less goes
into L5,...L9. 

All the L counters are about 25 meters from C0. The map into
unpacker variables is as follows: 

   tdc(1)   A  = L3                  adc(37)   A
                                     adc(38)   L1 
   tdc(9)   K1 = BH2                 adc(39)   L2
   tdc(10)  K2 = BV2                 adc(40)   pbarcal
   tdc(15)  K3 = BH1                 adc(41)   L5
   tdc(16)  K4 = BV1                 adc(42)   nbarcal 

   tdc(37)  L4 = pbarcal             adc(43)   L7
   tdc(38)  L5                       adc(44)   K4
   tdc(39)  L6 = nbarcal             adc(45)   K3  
   tdc(40)  L7                       adc(46)   K1
                                     adc(47)   L8
   tdc(41)  L8                       adc(48)   L9
   tdc(46)  L9
   tdc(47)  L1 = T (tiny counter)
   tdc(48)  L2 = needle counter 

We ran out of ADC spigots possessing the big delay gate needed for
upstream counters, and K2 = BV2 was sacrificed. 

                                     bj