1) We concluded that we had allow for the signature of a slow
monopole catalyzing proton decay. This leads to a prompt muon
signal preceding the slow monopole. This is shown schematically
below for a monopole entering from above MACRO- the muons from
proton decay in the tunnel roof can penetrate to the center layer.
Keep in mind that the muons and monopole trace need not be in the
same tank:
T ---- --------- -----------------------------------------------
| |___|
C ---- -------------------------- ------------------------------
| |___|
B ----------------------------------------------- ------- ------
| |___|
The exact details of this picture also depend on the cross section for
proton decay catalysis: this effects the number of muons and their
time spread and whether or not they can overlap the monopole trace itself.
This signature puts us in a difficult situation. Basically, for all
triggers we must delay the stop by 1000 us. The rest of the discussion
pertained to the impact on deadtime and data size.
2) Some benchmarks:
500 = number of channels per MACRO
64 K = total memory per channel
160 us = minimum time stored in 64K buffer of wfd
60 ms = typical time stored in 64K buffer, assuming 100kHz bg.
3 Mb/s = transfer rate for straight reads
.3 Mb/s = crude guess at transfer rate including extra code
11 Mb/s = Block transfer rate
The transfer rate for my MVME167 is 50% faster than for the VME-uVaX + VIC;
this difference is ignored because of the uncertainty in .3 Mb/s.
3) This is a table of triggers sorted by the amount of interesting
information. The second column is the amount of information we wish
to record; for reasons of code efficiency, I hypothesize that it will
actually be quantized by 160 us (it is faster to count rollovers than
to calculate exact time windows). The third column is the rate of each
trigger. The next column is the deadtime fraction. The last column is
the amount of the detector to read-out (I somehow neglected to record
this, so I am going by memory to some extent).
SLOW MONOPOLE (1 face) 1000us high 1.6e-3 a few channels
SLOW MONOPOLE (2 face) 1000us 10/hr 2 SM
S.T. MONOPOLE 1000us need 10/hr 2 SM
FAST MONOPOLE 10us 1/hr trigger channels (?)
LIP with S.T. 2us 600/hr 1e-2 trigger channels
ERP MUON 2us 60/hr 1e-2 2 SM
CSPAM 200ns 600/hr 2e-2 trigger channels (?)
LIP w/o S.T. 200ns 1000/hr 1.5e-2 trigger channels