It's suggested that every WALTA teacher build time into their year to bring the entire detector apparatus back into their classroom or prep room. Whether the teacher is working with a seleect group of students, a class, or several classes is up to the teacher.
Maintenance activities
The entire process of testing for light leaks, setting thresholds, and determining efficiencies should be a starting point for each new group of students. This should be done at least once a year. It's the same set of steps that were performed during the refurbishing of the CASA detectors.
It may be necessary to repeat steps b & c in order to "zero in" on the best threshold and operating voltages for individual detectors....
Check high-voltage settings frequently. These will change as more detectors are plugged into the high-voltage supply box, and may drift as well when the high voltage box warms up or cools off.
Experiments for students
These are suggestions and starting points. Use your imagination !
a) Make a vertical telescope using boxes or crates. Calculate the "acceptance" : the size of the wedge of sky from which an incoming particle will strike all you detectors. Change the spacing between detectors and compare the acceptance to counts / unit time.
b) Make a horizontal coincidence counter by laying all of your detectors in the same plane, on the floor or counters or tables. Compare coincidence rates versus several kinds of spacing arrangements and different spacing arrangements.
c) Compare coincidence rates verus time of day, night, season, year, weather, barometric pressure, or solar activity cycle.
d) Compare counts for a basement versus rooftop detector.
e) Compare counts versus altitude
f) With a vertical-type telescope which can be aimed, compare counts from various parts of the sky.
g) Compare counts versus compass orientation.
h) Compare shielding arrangements.
i) Does the aluminun foil wrapping of the scintillator affect efficiency ?