-----Original Message----- From: Eric Walker >If I have understood what I have read, the decay they're seeing is a signal >being picked up by GM #1 when a lead barrier is interposed between it and >the active material. So for the signal to be due to a fusion reaction, >would this reaction need to be happening on the side of the lead barrier >opposite the active material?
As a general caveat - when one is attempting to use lead as shield - and measure low count rates, Pb-214 can interfere. This isotope is found in surprising large amounts in natural lead - given its 10 hour half-life. Also there is the mother of all radiation anomalies - Radon, which is gaseous and can decay to 214Pb; and radon is quite prevalent in some locations and is attracted to certain materials due to static electric charge. Therefore, in cases where radon is found in relative abundance in the air - a good bet for the source of decay in the several hour half-life range, is radon daughter products. Note how easy it is to find high radiation counts on your computer monitor, for instance. Compare the CPM here and in the test in question. http://www.blackcatsystems.com/GM/experiments/ex1.html Here is a Radon map. http://denr.sd.gov/des/aq/images/Radonmap.gif If a testing lab is in the "high radon potential" zones, such as say - Northern New Mexico, efforts must be made to exclude radon counts. Jones
