Search found 2329 matches

by Carl Willis
Mon Apr 07, 2003 6:03 pm
Forum: Images du Jour
Topic: Archived - Neutrons v. Potential curve
Replies: 1
Views: 4030

Archived - Neutrons v. Potential curve

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...
by Carl Willis
Mon Apr 07, 2003 5:46 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: IE curve for fusor
Replies: 10
Views: 5419

IE curve for fusor

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...
by Carl Willis
Mon Apr 07, 2003 6:15 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: More activation experiments
Replies: 1
Views: 6373

More activation experiments

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...
by Carl Willis
Mon Apr 07, 2003 5:29 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Fertilizer source...
Replies: 4
Views: 3268

Re: Fertilizer source...

<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...
by Carl Willis
Thu Mar 06, 2003 3:44 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Moderators- Whats best
Replies: 3
Views: 2163

Re: Moderators- Whats best

<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...
by Carl Willis
Thu Feb 27, 2003 6:51 pm
Forum: Fusor and/or General Fusion Theory (& FAQs)
Topic: The neutron as a particle - my thoughts
Replies: 24
Views: 8726

Re: The neutron as a particle - my thoughts

<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...
by Carl Willis
Thu Feb 27, 2003 6:12 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Vanadium Activation
Replies: 3
Views: 3913

Re: Vanadium Activation

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
by Carl Willis
Wed Feb 26, 2003 4:15 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Vanadium Activation
Replies: 3
Views: 3913

Vanadium Activation

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...
by Carl Willis
Wed Feb 26, 2003 4:03 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Aluminum Activation (barely!!)
Replies: 1
Views: 3145

Aluminum Activation (barely!!)

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...
by Carl Willis
Wed Feb 26, 2003 3:51 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Prompt activation spectrum of Cadmium
Replies: 3
Views: 3621

Prompt activation spectrum of Cadmium

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...