WATCHMAN is looking at commercial products: (CAEN peak sensing ADC) Digitizer 4 nsec bins - commercial system Single crate… 8 channels for $7k $100K
Discussion suggested that we treat the electronics with two parallel but unified systems: a fast system and a slow system. We can split the signal using a passive component from CDF (Henry has spares). Thus the fast component provides a
Plan 0: PSEC electronics with a splitter
which will be common to both the PMT and LAPPD systems, regardless of the slow electronics. We still need to look at options for the “slow system”. In preparing for this summer, we have three options:
Plan A: WATCHBOY (borrowing) - 52 channels (event time but no individual PMT readout) talk to Adam
Plan B: Mircea boards, Mircea - 500 MHz sampling and 125 MHz for Koto (8 channels per board) much cheaper than Caen split the signal (KOTO)
Plan C: Frank could look into options at the 100 MHz level (exploration)
every 0.2 seconds continuous readout during the beam for 20 microseconds (may be enough to write out everything) 1000 MHz*30 microseconds = 3000 samples (30-40 microseconds) What's the dead time for 300 microsecond switching between a long and short window, may be rough.
event characteristics: 1m^2 * 100 Hz cosmic rays 0.23 rock + contained events per second
We need to think about calibration. In addition to triggering on beam, we would like off-beam triggering. For example, cosmic muons for calibration. We can use the PSEC system for that.
(Californium sources to measure neutron tagging efficiencies)
Henry point person-power question - we need people, even to support PSEC4. Eric will be leaving, so even to the extent that PSEC 4 is “worked out”, we need people to take ownership.
5m^2, 1” thick scintillator paddles (for charged particles) - 3% neutron efficiency, could be used as our forward muon veto. We want that. 5 tons of mineral oil (to be made into scintillator, but more of a pain)