This workshop was conducted over three weekends, each session on Saturdays 9-12 AM. During the first session scientillators and light guides were were polished and glued together. They were wrapped and attached to the phototube and tested for light leaks during the second session. Finished counters were mounted and attached to the readout electronics and tested at the last session.
I designed and developed the scintillator and the assembly procedure for the workshop. The readout electronics board I designed had the capability to to count singles from each counter, coincidences, and decay time of a muon decaying in the second counter. It worked without interfacing to a computer. So after detecting a muon decay event, circuit has to be reset. 2-4 muon decay events were detected per hour.
This unit was built with discrete ICs so that students can trace the circuit and have a better idea of the functioning of the device. The circuit board is upgradable to interface to a computer. But at this stage it was ment to take data manually. Althought at a later stage interfacing to a computer would make it more convenient to use, at the beginning it is more instructive for students to collect data and plot them manually. That way they get really involed in the experiment and have a first hand experience in taking data and analyzing, which would be hindered by using a computer to automate the process.
Here are few photos from the work shop. More pictures of the workshop are at the NJ physics teachers web page
Readout electronics circuit board I designed and built. Top four digit counter gives either coincidence or single counter rates depending on the setting of the toggle switch. Lower two digit counter gives the time for a secondary pulse from the lower counter (from a muon decay) if any, in units of 100 ns. It also provides the 5V DC power for photo tubes.
polishing the scintillator
attaching the scintillator to the light guide with epoxy
wrapping a glued scintillaor and light guide.
preparing to attach the phototube to the scintillator.
attaching to the photo tube
Steve with the prototype readout board at the first workshop.
me demonstrating the control board.
a finished unit
a finished unit ready for testing