> I don't know now where to get a bare silicon photo diode any > more but this approach would be some $1000 less then some > previous pointers - maybe < $20. Even Geiger counters can be > in the $150 Or less range > http://www.blackcatsystems.com/GM/geiger_counter.html > Geiger Counter Nuclear Radiation Detector Alpha Beta Gamma X-Ray Quick fun question: How many people live downwind of a nuke power plant and do NOT own a Geiger counter? I'll raise my hand first.... San OH NO is just a bit north west of here. I actually DO own a Geiger counter (only because of inheritance from my dad who was a survival nut) but have not unpacked it or powered it up in years. Next question: How many people personally know someone who has worked at a nuke plant for years, lives downwind, and has his Geiger counter (with alarm function, power adapter and backup batteries) attached to the wall of his living room? He says he finds the quiet, random clicking comforting. His RV is parked just outside and always stocked with gas/food/water, etc... Me again... He says if the generator bearings ever fry, the turbine and generator will come off the hinges... And they are mounted and spin in a direction that will cause them to then roll directly into the reactor. He is something of a goober and I don't believe everything he tells me, but... And who was it going on about people hiding their head in the sand the other day? Hummm... --- James. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist