Cs-137

I have found a relatively inexpensive source for a Cs137 check source. It is in the form of a 'new old stock' Raytheon CK1097-15 spark gap from ebay.co.uk. (No longer listed - You may find one by searching.) It isn't very active though. I bought it to use as a calibration source for my gamma spectrometer project I'm on with. I tested using a LND712 tube and got about 55 CPM tops (background was ~17 CPM) and had to place the spark gap right up to the end window of the LND712. Whilst not very active it should work well for calibration purposes. It's hard to photo the printing on the spark gap