Fusor Forums

Here's a neutron CPM vs. potential curve generated by running my fusor at low power, over a range of voltages. Pressure was relatively steady at 8.7 mtorr throughout for the data used. Note, however, that current was not held constant--it rises with potential as shown in the curve in the "HV and Fus...

I have been measuring the relationship between current and voltage in my fusor, but it's actually a pretty challenging task to get "clean" data. For one thing, thermionic emission from the grid causes runaway problems at high power. Also, the power limiting imposed by my saturable-core inductor ball...

I have still been working on neutron activation, with a tiny bit more success. I am now confident that I can activate gold, although the long half-life (~2.7 days) of Au-198 and the very small quantity (0.4 g) that I have make detecting it quite challenging. Below are two spectra plotted together--o...

<t>Fertilizers are often high in uranium daughters as well as potassium. For some reason, the phosphate rock used to make phosphate fertilizer contains high percentages of radium (it must form a very insoluble phosphate). For example, I have some phosphate nodules from the NC coast that are quite de...

<t>Water is really the best--in terms of getting your experiment as close to the poissor as possible and thermalizing the neutrons. You don't need as much water (thickness wise) as you do wax, oil, HDPE, or anything else that I am aware of.<br/> <br/> On the downside, anything with H-1 in it has a r...

<t>The whole issue of spin aside, it is my understanding (I hope I'm not reiterating the obvious or what has already been said) that the neutrino is needed to conserve momentum. Exactly what the properties are of the chargeless and nearly if not massless emission is up for debate. But by experimenta...

Hi Larry,

Mind if I ask where this vanadium grease might be obtained, what it is called, and what vanadium compound is in it? Sounds like a good lead. Thanks.

Carl

Here is another short-lived nuclide activation experiment, a good bit more successful than aluminum in getting decent data. Vanadium-51 has a thermal neut. capture cross section of 6.4 barns and the product, V-52, has a half-life of 3.76 min. It emits gammas of 1.434 MeV. Lucky for me, there is a Ch...

Check it out. A big 3" dia. bottle of -325 mesh aluminum (usually used for fireworks, by the way) was put behind two inches of water moderation and irradiated for some 10 minutes at some of the highest sustained neutron rates my fusor has yet produced (the needle was into the 50 mrem / hr range at t...

This weekend was a lot of fun. Brian Willard, fellow list member and local from Liberty, NC came up to Guilford and we ran the fusor. This time the target was a small flat piece of Wood's metal (~15% Cd) placed in front of the 1.5" NaI(Tl) counter for the duration of a 10-minute fusor run. Between f...