detector details

Board final version: Note Lemo signal cable connectors	S1 : Beeper on/off S2 : Up = single count from top detector Center = coincidence count from both detectors Down = single count from bottom detector S3 : Up = Count Down = reset to zero Note : detector may show bad numerical display on power-up. Just reset with this switch. S4 : Up = count indefinitely Down = Timed count (approx 1 minute) Note : Timed count does not start reliably. Toggle switch if it does not start.
Battery Back up.	The battery pack is wired in parallel with the 12 volt power supply input. When the detector is supplied with a 12-volt power supply, the batteries will charge, whether or not the detector is on. Each D-cell Ni-Cad battery charges to 1.2 volts. Ni-Cad batteries do not hold charge more than a few days, so the detector should be stored plugged in & off when not in use. The black batteries are much older than the silver, and should be checked 1st if the unit won't run off the battery pack. The detector will run fine until the battery pack drops below about 7 volts. Below 7 volts, the detector will appear to not count, and the numerical display will be dim and/or bad.
	The scintillator paddle, PMT, and base, with a temporary wood splint taped on for transport. The joint between the scintillator and PMT is made with clear epoxy, and has been problematic, breaking more than once. Jim Madsen of UW-River Falls & I devised a more robust wood support system to support this joint. The scintillator was cut from a CASA scintillator owned by the University of Washington WALTA group. To increase light production and create more surface area for the epoxy joint, the scintillator inside the light-proof black tape is double thickness.
	The PMTs and bases are courtesy of Thomas Jordan, PI for QuarkNet at Fermilab. They run from a 5 volt low current DC supply from the circuit board, and have no exposed high voltage contacts. The vernier dial allows the high voltage to be set, and a switch locks the setting.
	The red plug is the 5VDC power supply. The 2 plugs are in parallel, so either can be used.
	The green Lemo signal cable is attached here.
	Finished working detector, 7/4/2002, ready for luggage check-in to the University of Wisconsin, River Falls, for the Astronomy in the Ice course. No problems checking it in, and it worked on arrival !
	Detail of power switch and power plug-in. Switch to the right turns on the detector, whether powered by battery pack or transformer. Power plug-in is switched, so it presents some surprises if you try to bypass it and input 12V DC from a power supply via alligator clips.
	Detail of new splint system for PMT/scintillator junction. This joint has failed 3x in this detector, and in other detectors I know of. This splint will (hopefully) prevent that problem, and make the detector ready to ship to the South Pole, Sweden, and anywhere else !
	The designer of the new splint system, Professor James Madsen of UW- River Falls, fits the final pieces. Detail of the splinted detector installed in the lower box.