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homebuilt neutron source?

Posted: Tue Sep 06, 2011 11:19 pm
by Spencer DePue
Hi all,
I haven't posted in a while, went to college, left for medical reasons... going to community college. What a roller coaster ride. I want to start a small scale nuclear company, but lets face it, I am young and need proof of concept for some of my ideas. I thought that the simplest ideas are often the best ones to go with when starting. I also stopped playing with magnetrons.

I recently watched Carl Willis's youtube video on beryllium/alpha neutron sources. Very neat video by the way. This has sparked some curiosity for a new idea which really is just an adaptation to a proven 1920's (around that time) device called a atomic battery.

Adding uranophane to a borosilicate test tube with an metal electrode rod stuck inside of it and metal foil wrapped around it. Adding a beryllium ingot, and measuring the voltage from the two electrodes with a multimeter. And to definitely stay away and add lots of shielding of different kinds.

Please tell me why this wont work, will work, or how unbelievably crazy I am to think this will work. Thanks!

Re: homebuilt neutron source?

Posted: Wed Sep 07, 2011 9:41 am
by Richard Hull
It won't work and, while not crazy, is terribly naive. Uranophane, even a ton of it, is far too weak to generate any effective or useful electricity in any battery scenario. There are no atomic batteries on the market nor will there ever be unless in a controlled military environment.

The average AA penlight cell can give easily a full watt of electricity for a short period. For a nuclear battery to do this, you would need several watt seconds of radiation from your source as the normal collection/conversion methods, (thermal), are not efficient.

Let us say the impossible is achieved and you have a one watt second source of radiation and are getting the watt out. This would have to be charge based system as a thermal system is far less efficient. With unit charges, say, from Sr90 you would need a source emitting ~10e19 electrons/sec! This is a mega curie source and would be better used thermally in this case and you might get by with only a 100 curie source. (very lethal) You would never get an NRC license to "play nuclear battery"

Uranophane giving off 2,200,000 particles per minute is a 1 microcurie source. 100 million times too small.

Forget the nuclear battery idea. It is a really superlative looser effort.

Richard Hull

Re: homebuilt neutron source?

Posted: Wed Sep 07, 2011 10:41 am
by Spencer DePue
Thanks for the input. I figured it might be too weak. What would you recommend in terms of nuclear technology that I could develop as a small start up company? I have not started the company yet, but I hope to start within a year.

One question however. Uranophane is roughly 40% uranium 238. I have enough to fit in a large test tube. If I were to use a 1 gram beryllium ingot to capture some of those alpha particles, spitting out neutrons, roughly speaking, how much of those fast neutrons would induce fission in the U238? I don't think it would be a good percentage.

Re: homebuilt neutron source?

Posted: Wed Sep 07, 2011 11:40 am
by Richard Hull
You might expect right around 0.0000001 fissions per second or one fission every month or so due to the process you describe. Give it all up! U-238 will self-fission faster, as you would be producing close to zero fast neutrons in your scenario. Nothing of value or even detectable here.

You cannot start up any business doing anything nuclear until you know a whole lot more about it than you do. Your questions are like those of a junior high schooler who has just read his first book on radiation. Perhaps several years of work in the field following a graduate degree in nuclear physics might be in order.

It is obvious you have no idea about even the rough order of magnitudes involved within radiation physics.

Richard Hull

Re: homebuilt neutron source?

Posted: Wed Sep 07, 2011 1:18 pm
by George Dowell
FYI
RE: solid state neutron generator.
Richard is 1000% right. Far to dangerous and probably illegal from a number of standpoints.

Before the anticipated 2005 NRC redo of rules pertaining to radium, we were informed that they would take direct control of all radium products away from the states.

I happened to have 10,000 radium watch hands
at that time and knew I would be voluntarily of forcibly divested of them.

Naturally I had the try the Ra-Be reaction, which is one of the more successful albeit not practical N reactions.

THIS LASHUP WAS DONE UNDER LAB CONDITIONS 100%, respirators and all, and did actually produce a few measurable neutrons. A few. It took 24 hour measurements with very expensive equipment, the best available.

After one experiment which I later labeled as "oops!" the device was dismantle and the watch hands gotten rid of through legal channels.

Carl's rented Po-210 source is legal even though it is being used in what the NRC likes to call "unintended usage", I doubt anyone will raise an eyebrow UNLESS
you make one and try to sell it (Then "Do not pass GO, go directly to jail " applies- Been there/done that). ALL generally licensed device (smoke detectors, EXIT lights et.a.l have use restrictions)
By the way those 500 microCurie alpha sources are far and away the most powerful alpha sources available today. The only UNRESTRICTED pure alpha source is a sealed source of Po-210 @ 1/10 microCurie, with a written prohibition against combining sources to obtain higher activity.

See NRC Regulations (10 CFR) >Part Index > ยง 30.71 especially Schedule B.

All above is just my opinion but I have spent the last 10 years talking at length with the folks at the NRC trying to get clarifications.

No doubt some consider me a ninny.


geo

Re: homebuilt neutron source?

Posted: Wed Sep 07, 2011 1:45 pm
by Spencer DePue
The first thing I mentioned in this post regarding the battery was that I prove that something indeed works. And no, I do not ever plan on selling a prototype battery, or any other possibly proven device without the NRC licensing. I respect everyone's advice. However I think I know a little more than what I nonchalantly write on this forum. I think a lot of what I say is for the most part misunderstood.. Anyway, I know the people on this forum are very skilled at what they do, and have a lot more knowledge than myself.

And if I should give up the nuclear battery idea, why doesn't everyone else. I mean, if they are so terrible at what they do why even use them? I think the truth lies with their potential to be used for years on end without needing to be recharged like conventional batteries. High voltage, terribly low current batteries have uses too, don't they?

Re: homebuilt neutron source?

Posted: Wed Sep 07, 2011 2:28 pm
by Chris Bradley
Spencer DePue wrote:
> What would you recommend in terms of nuclear technology that I could develop as a small start up company? I have not started the company yet, but I hope to start within a year.

Spencer, please stop joking around.

What happened to that 'fusor in two weeks'? That'd be a start for you.

Re: homebuilt neutron source?

Posted: Wed Sep 07, 2011 2:36 pm
by George Dowell
Nuclear batteries/home made neutron sources:
Yes they work fine but as Richard mentions, they are used under tightly controlled
areas of endeavor, i.e. NASA and military. Our responses are usually archived to a larger group of (future) students beyond the individual raising the present question.

Search RTG, Decay Heat, SNAP generators, Beta Battery, Non fissile Pu-238 pacemakers (now discontinued).

A typical satellite might have a dozen (sometimes many more) isotopic electrical generators and heat sources.

Neutron sources and others are used on Mars rovers to remotely analyze elements ( esp. the search for water Dynamic Albedo of Neutrons (DAN)) by NAA.
Also search PIXE (Particle Induced X-ray Emission - a favorite of mine using beta particles.) APXS and Curium 244.

Proof of concept is well within the realm of a student lab, just not a working
device.

Pictures attached are from one of our recent trip to Oak Ridge TN

To keep focused on the core subject matter of this forum- neutrons;

We will be seeing many many more neutron sources of all types being developed for scientific uses, but primarily driven by the medical field, specifically Boron Neutron Capture Therapy. BCNT is well into development (outside USA)and uses many of the techniques you see mentioned on this forum:
Enriched Boron B-10's neutron cross section, B-10,N> B11> a, Li reaction, moderators, accelerator produced neutron, fusion (T(d, n) 4He).



Your co-student
Geo

Re: homebuilt neutron source?

Posted: Wed Sep 07, 2011 2:42 pm
by Spencer DePue
I'm not joking around. I had to leave college that was an opportunity down the drain. Ever since I was fourteen I wanted to own an energy company, and I am trying to get to this goal. Its so difficult having a brain that goes 200 mph 24/7. I cant stop thinking about what I want to do for the world in terms of energy. I joined this forum looking for help with these ideas, and all I seem to get is criticism. Some constructive, some hurtful. That's why I am asking for advice for the nuclear energy idea. I have some pretty advanced concepts that could never be built without paying an engineer 100,000 dollars a year or more. I want to design atomic batteries to kick off the business. (while at community college).

Re: homebuilt neutron source?

Posted: Wed Sep 07, 2011 3:08 pm
by Chris Bradley
Spencer DePue wrote:
> Its so difficult having a brain that goes 200 mph 24/7. I cant stop thinking about what I want to do for the world in terms of energy.
The problem seems to be that it looks like 200mph in tiny spirals, rather than in a coherent direction. Whatever you do in life, it won't be achieved by imitating a whirlwind. 'Achievement' takes years of slow, boring stuff where you get things wrong over and over, keep on trying but even when you do you end up thinking few are listening and even fewer care. This is occasioned by a few, interspersed, very infrequent random moments of 'yeeha'. If you are not experiencing slow laborious stuff that you wished you could just ask someone else to do for you, then you're almost surely on the wrong track.



> I joined this forum looking for help with these ideas, and all I seem to get is criticism.
So you are already getting the best form of help, then! Are you expecting to get congratulations and back-pats on *not* getting done the things you said you were looking at? What help would it be to you if no-one pointed out that you really need to knuckle down to 'doing something' as a means to learn? No-one can develop your ideas for you.

If you had done a little research on nuclear batteries, you'd find a variety of attempts, both old and new. Better to come to the forum with a document/link and say 'I'd like to try this, and I will go about it by ..X..Y..Z'. Whereas, at the moment you are acting as a spoon-feeder, even if you don't realise it, which is a comment to which you will probably reply 'Why don't you just help me with some links, then?' (which'd have missed the point).

Re: homebuilt neutron source?

Posted: Wed Sep 07, 2011 3:14 pm
by Spencer DePue
I agree, your absolutely right. I should take time to slow down and move in a consistent direction as opposed to making up all sorts of newfangled ideas and never sticking with one. This forum has actually helped me a lot with practicality and which ideas are worth endeavoring. I will try to do better with this.

Re: homebuilt neutron source?

Posted: Wed Sep 07, 2011 3:23 pm
by Chris Bradley
Spencer,

Not wishing to be all-stick and no-carrot, may I suggest this as an 'exercise':

Take a look at;

http://www.rexresearch.com/nucell/nucell.htm

..spend a week or two researching what it is claiming, then if you have arrived at some well-formed conclusions, come back on the forum and (in an appropriate forum - this one isn't it) discuss with us here what your further reading has drawn up as to the strengths and/or weaknesses of the claims in it. In other words, do you think this should work, or not work, and why?

Re: homebuilt neutron source?

Posted: Wed Sep 07, 2011 3:43 pm
by Rob Osterman
Spencer,

It's fun to have a lot of ideas that would seem to work, the difficult part is to back it up with the advanced science (something I am still struggling with as well!). I found that searching questions through Google only provided half-answers, and often times poor advice from different forums (fusor.net being the exception).

What helped me a bit is by going through MIT's Open Course Ware on Nuclear Engineering. A lot of the lectures and slides are available for free from the undergraduate level all the way to the graduate. It gives a good primer for a more guided self-education. Check out the link, you can spend hours looking through the information. http://ocw.mit.edu/courses/nuclear-engineering/

Re: homebuilt neutron source?

Posted: Wed Sep 07, 2011 4:17 pm
by George Dowell
"Check out the link, you can spend hours looking through the information. http://ocw.mit.edu/courses/nuclear-engineering/

Days/weeks in my case. I read slow. I understand slower.

Geo

Re: homebuilt neutron source?

Posted: Wed Sep 07, 2011 4:48 pm
by Carl Willis
The quantity of uranophane that would fit into a typical test tube has a few microcuries of alpha activity in it. Under the best of circumstances, assuming a Po-210 alpha spectrum, one can obtain 80 neutrons / 1E+06 alpha particles from the (a,n) reaction on beryllium. So at best, you'd be looking at neutron yield in the single digits per second with this activity available. Detecting that is practically impossible.

But it gets worse. Unfortunately, the situation you describe is far from ideal as only the uranium atoms within a few microns of the beryllium surface can contribute to the reaction--the vast majority of alpha particles from the volume will be stopped before they reach the beryllium. Furthermore, the (a,n) yield is highly dependent on incident energy, and your alpha particles predominantly from U-238 at a max of ~4.2 MeV have nowhere near the yield as those from radium, Po-210, and Am-241. I would be surprised to see even 1/1000 of that 80/1E+06 figure, making other sources of neutrons--like (a,n) on silicon and oxygen in the uranophane and spontaneous fission of U-238--competitive. The numbers of total neutrons will be distinguishable from background only by the most rigorous technique using the most sensitive equipment.

The battery part of the idea can be dismissed wholesale from some cursory considerations of energetics.

-Carl

Re: homebuilt neutron source?

Posted: Wed Sep 07, 2011 5:13 pm
by Spencer DePue
I had the idea the yield would be terrible. As for Paul Browns battery, its a definite hoax and bad science. But now I am disappointed. I thought I was going to make a "nuclear magnetron". And now that it is labeled as bad science, I cant develop it without getting crappy efficiencies.. Here is what I found.

Claim 1: No waste or nuclear reaction
False: Really? a nuclear battery with no byproducts or nuclear reaction.. hmmm. Thats the indicator
that this is completely bad science.

Claim 2: Nucell yields 7500 watts/gram of Sr90
False: I did some math. Based on some common sources, Sr90 has an activity of 5.094x10^12 Becquerels. Multiply that by 8.747888222x10^-14 joules(energy of the beta particles) ( 546,000 electronvolts converted to joules) and the answer is .445 watts per gram of Sr90. Nice try.

Claim 3: magnetic energy of the emitted particles is greater than the kinetic energy.
False: In order for the particles to have magnetic energy, they have to have kinetic energy first, which will degrade as heat ultimately reducing this magnetically attractive claim to be false.

The list goes on...

Re: homebuilt neutron source?

Posted: Wed Sep 07, 2011 5:26 pm
by Chris Bradley
Spencer DePue wrote:
> Claim 1: No waste or nuclear reaction False: Really? a nuclear battery with no byproducts or nuclear reaction.. hmmm. Thats the indicator that this is completely bad science.
I think that part is referring to 'just beta emissions', resulting in 'electrons' and just stable isotopes remaining (just like when activated materials decay back to something stable).


> Claim 2: Nucell yields 7500 watts/gram of Sr90 False: I did some math. Based on some common sources, Sr90 has an activity of 5.094x10^12 Becquerels. Multiply that by 8.747888222x10^-14 joules(energy of the beta particles) ( 546,000 electronvolts converted to joules) and the answer is .445 watts per gram of Sr90. Nice try.
But what does the Sr90 decay into, and how much energy could you get out of whatever it decays into?

Re: homebuilt neutron source?

Posted: Wed Sep 07, 2011 5:41 pm
by Spencer DePue
Woah, missed a piece of data, according to the combined decay energy of strontium 90 and yttrium 90, it would be around 7500 watts.

Yttrium 90: 2279800 Mev to joules: 3.652643877e-13 joules x 20000 Tbq/gram= 7305 joules
plus other decay energies from Sr 90 and occasional gamma ray.


Interesting.. I thought of a magnetron in reverse configuration utilizing nuclear decay yesterday, and then I came across this. I doubt its as efficient as they claim. Lots of energy still wasted as heat.

Re: homebuilt neutron source?

Posted: Thu Sep 08, 2011 12:53 am
by jcs78227
Spencer DePue wrote:

> Yttrium 90: 2279800 Mev to joules: 3.652643877e-13 joules x 20000 Tbq/gram= 7305 joules
> plus other decay energies from Sr 90 and occasional gamma ray.

Careful on your math and units. The way you have it written, Yttrium-90 has a value of over two TRILLION electron volts. You probably intended a decimal point after the first digit...? Your sigfigs are all over the place in this thread, so even mentioning the uncertainty would be pointless.

I know you've been thoroughly dressed-down, so I'll trust you do it more carefully on paper.

J-

Re: homebuilt neutron source?

Posted: Thu Sep 08, 2011 9:57 am
by Richard Hull
Overall, this post and its responses have been instructional. What was learned....

Orders of magnitude are important when considering nuclear processes that seem great at first glance. The physics of nuclear processes is such that easy sources of real energy are just not to be had at the amateur or even the common manufacturing level.

No matter what nuclear process is used in a useful nuclear battery, the waste heat is always there. Oddly, this is actually the only nuclear battery technology, (trapping and using that heat), that works to give significant electrical outputs.

Any nuclear battery that might be produced is forced into controlled, government use and constant oversight due to the amount of isotopic material demanded.

In space, nuclear batteries, (thermionic generators), are a real valuable asset for long period, deep space missions where solar cells are no longer viable and common battery technology that they might charge is lifespan limited. Such generators/batteries are often "one-offs", designed for a specific mission and not picked up from any manufacturer's inventory

You can't make a useful, easily verifiable neutron source from any radioactive ore. (NORM).

Dreams and ideas are often quickly shattered by any number of real world issues blocking implementation.

Richard Hull