Activation of Indium...YES!

[Jon Rosenstiel]

The setup:
A 5.7 x 5.7cm, (2.25"), square of indium foil 0.23mm, (0.009"), thick mounted behind 15.2cm, (6"), of paraffin. The distance from the indium foil to the center of the fusor was about 25cm. (Through the paraffin moderator).

The experiment:
1. Fusor operated at an output of 1.6E+06n/s for 4 minutes.
Immediately following the run the count rate at the indium foil was 60.5cpm. (10 min count).
2. Another 10-minute count on the foil gave 56.2cpm.
3. A 10-minute background count gave 45.7cpm.
4. The indium foil was re-activated with another fusor run of 5 minutes at an output of 1.6E+06n/s.
5. Immediately following the run the count rate at the indium foil was 65.7cpm. (10 min count).
6. A 10-minute background count gave 45.2cpm.
7. A 10-minute count on the foil gave 54.9cpm.
8. A 10-minute background count gave 46.7cpm.
9. A 10-minute count on the foil gave 58.0cpm

It appears that I’ve managed to neutron activate a piece of indium foil. Cool!

Jon Rosenstiel

[guest]

That is great Jon!

It should take about 3-5 hours for the indium to go to back ground using the 54 min half life of In 116. The definitive test would be to gamma spec the foil and the telltale 1.29 mev gamma peak would give it up. Though a simple geiger test on the beta emission is more than adequate to show activation.

Richard Hull

[Starfire]

Very Cool Jon -- Tried any other elements yet?

[Jon Rosenstiel]

John Hendron. wrote:
> Very Cool Jon -- Tried any other elements yet?

Not yet, John, but my mind is defiantely churnin'.

[3l]

Hi Jon:

Might I suggest a silver main course followed by rhodium for dessert with a fine magnum of potassium permanganate for a after dinner drink?


Larry Leins
Fusor Tech

[Jon Rosenstiel]

Larry, you have pretty expensive tastes! How about McDonalds and a movie instead?

Jon Rosenstiel

[Jon Rosenstiel]

Richard Hull wrote:
>
> It should take about 3-5 hours for the indium to go to back ground using the 54 min half life of In 116. The definitive test would be to gamma spec the foil and the telltale 1.29 mev gamma peak would give it up. Though a simple geiger test on the beta emission is more than adequate to show activation.
>

Richard,

I played around with the indium activation a little more today. As you indicated, after 4 hours the foil was pretty much back to background. (Was 70cpm above background immediately after activation).
Something I noticed…. the foil seemed to activate quicker when totally surrounded by paraffin.

Another thing I hadn’t realized about indium, it’s slightly radioactive! When using my pancake probe it adds about 4cpm. Now I make sure I do my background counts with the probe on the foil. (Those darn pancake probes will pick up just about anything, won’t they)?

I'm having trouble finding information about gamma emission after neutron activation. I’ve found bits and pieces here and there, but nothing substantial. Where do I need to look? There’s prompt gammas and there’s delayed gammas, but how prompt or how delayed?

Also, what you’re doing with gamma spectroscopy is very interesting, something I think I would like to try. Would you please give me some pointers on the how and what?

Regards,
Jon Rosenstiel

[guest]

hi, just a newbie reading here... but ran across a post in another group about metalcasting (http://www.backyardmetalcasting.com/) of a guy that ended up with a bunch of indium.... i will post below... since he was looking fo aluminum, and you guys might want this... well.... still tring to figure out if I am up for the fusor project.... does look interesting.... reading..... will try not to post questions till i have all the old fourms read



from :http://pub42.bravenet.com/forum/fetch.p ... 3548766086

******* his site is at http://frugalmachinist.com

Well I had an opportunity to load up my pickup with all the aluminum ingots I wanted for dirt cheap.....read less than 5 cents per pound. Good deal says I. Off I go. Get ther, and go to load the stuff up. Hmmmmthese feel awfully heavy to be aluminum, although it does resemble aluminum. I ask, are you sure its aluminum, and the reply was yep, thats what was on the surplus auctions listing. We carried a piece over to a welding table and put the O/A torch to it. The flame barely touched it and it melted into a freeflow of smutty brown crap. Sure don't look like lauminum to me. We put a piecein a crucible and fired up the furnace. It just up and vaporized again leaving a smutty brown film. Hell I thihnk, I'll just let it be.

To make a long story shorter, the stuff turned out to be Indium and Cadmium, and was used as a thermal link for a project of the U S Navy. Melt point was about 137 deg or a bit lower. Cadmium and Indium are not to good of matals to be around, especially the fumes given off. Now I find out that the company that makes this stuff offered to buy it all back. The way I understand it its worth a small fortune, like big bucks. If I did not take it it was going to get hauled off and dumped in a gulley. Figured there was perhaps 400# of it, but after the guy counted the ingots and with the amount of ingots there was almost 2000# of the stuff. At first I was assuming it may have been a bismuth alloy, wehich would have been a great find for that price, as thatb stuff is great for a lot of uses.

I just knew I should have taken the stuff for that price when I had the chance. Then again I may be dead right now also, or at the least suffering with cadmium poisoning. Just becarefull of what you throw in them crucibles, and always stay out of the fumes and smoke.

*************

so maybe usefull for someone????????

mike