http://www.findarticles.com/cf_0/m1111/n1782_v297/21281407/p1/article.jhtml?term=

:eek:

This guy is my hero. Anybody want to try this?

I heard something about that a while ago. I would definatly try it if I had the elements and a friend to keep me in check. I would try my best to prevent a contamination though. It would be nice to rely on something like that instead of the unreliable power company I use, great back up if you could fuel it, safely and not let the nuclear regulatory comission in on it.

The kid was making a breeder reactor, not a bomb. This isn't exactly the place for this topic- I vote it be moved to the WC.

Yeah, it should be moved. You'd think of all his research he would have learned alitle about safety. Damn, to illegaly purify radium and americium would require a large safety margin if you asked me I would have spent that thousand dollars he spent on bateries on a proper suit and some various metal sheeting to coat the shed in. Sounds a little to costly for me but it would be fun.

The reason I posted this thread in the HE section was because I was hoping to build on David's OTC research, and discuss the theoretical prospect of building a nuclear explosive. It would require the radioactive fuel he attained, a structured core, some wiring, and and HE... But, the water cooler is fine by me, I just wasn't sure. Anyway, does anybody know if they still sell those radium clocks, I think David operated in the mid-late 80's so they might have disappeared off the market, but I know for sure that smoke detectors and thorium lanterns are still pletiful. I doubt anybody here will actually build a nuclear weapon, as testing it would pose problems, and to do to so you would have to be a megalomaniac...

Radium watch dials went away by the mid 60's. United Nuclear still sells various radioactive ores- But it's hard to think of this as being a viable project.

The report gives some pretty good information on how he obtained the substances he needed. The guy's perserverence was amazing, proving that when there's a will, there's a way...

I don't think that I'd want to try "experimenting" with nuclear material though. At least not until I acquire large amounts of shielding materials. Was the guy charged for any offences for building the reactor?

I dont beleive he was charged with anything, he wasnt over 18 at the time so it was only juvenile offenses anyway.

As for this part... what is the author on about??!!??

" As she huddled with a group of nervous neighbors, though, Pease heard one resident claim to have awoken late one night to see the potting shed emitting an eerie glow."

Unlike cartoon animators beleifs, radioactive materials dont glow green! =P Any idea what this is about??

it doesn't really fit into HE's since it doesn't 'detonate'. moving...

Yeah, unfortunately they stopped making those clocks, but maybe an antique store, or E-bay would have it. My chemistry teacher said that while teaching the nuclear unit, the most radioactive thing he's ever put under his geiger counter was an old clock a student brought in, and this was back around 93-95, so its still possible. As far as radioactive shielding, I'm pretty sure it wouldn't be to hard to get any, there are numerous suppliers of full NCB gas masks and suits, selling them to people, saying its good to have it just in case. Also the lab where I work as an intern works with numerous radioactive isotopes including P-32, P-33, H-3, as well as radioactive calcium and iodine, and their shielding is simply a large glass shield which looks like it shouldn't be to hard to obtain. Geiger counters aren't to hard to obtain either. There is a catalog called the sovietski collection which sells "soviet" merchandise and one of their things is a geiger counter for around $50 and www.sciplus.com sells one for $125.00. To tell you the truth I am quite tempted by this project, I just don't have the $cash.

I already have a geiger counter and have searched the entire mountian side(believe me hours on end) and have not even gotten the needle to move. I should be looking around my town for sources of radiation though not to build a nuclear device, just to have. I could see my self trying that though, not without carefully thought up safety measures and about a thousand dollars in shielding. Make a great science fair project though, imagine their faces when you tell them that it's a nuclear breeder reactor. somebody should try firing small doses ov various forms of radiation in to frogs or fish eggs. That would be a great science fair project.

Um, where are you prospecting for radioactive ores? They're not just on every gravel pile, you know! Take the geiger counter to the thrift shops, antique stores & etc. Hold it up to old orange or yellow glazed pottery- You might get a surprise.

I was curious if the U-233 that David produced would be considered weapons grade? Also, don't most geiger counters come with a small radioactive sample so you know if its working.

According to The Nuclear Weapons FAQ (http://nuclearweaponarchive.org/Nwfaq/Nfaq6.html#nfaq6.2) Despite the gamma and neutron emission drawbacks, U-233 is otherwise an excellent primary fissile material. It has a much smaller critical mass than U-235, and its nuclear characteristics are similar to plutonium. The U.S. conducted its first test of a U-233 bomb core in Teapot MET in 1957 and has conducted quite a number of bomb tests using this isotope, although the purpose of these tests is not clear. India is believed to have produced U-233 as part of its weapons research and development, and officially includes U-233 breeding as part of its nuclear power program.

I dont know if this will be helpful or not but this article below tells of radioactive material you can get from ebay. The problem is its kind of "shady" about the details. I could not find the marble on ebay but they had a bunch of glass uranium dishes, after you changed the search to just uranium. So heres the site, Havent done html in years dont know if the link will work so ill try it with and w/o the code. <a href="http://www.bluemud.org/article/23605 ">Here </a><br> http://www.bluemud.org/article/23605

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Rhadon

Actualy my geiger counter is old and I got it from my paranoid grandad and he paied top dollar for it so it should be working but I don't know. He also had a calibrated survey meter wich we threw out(damn it). His father was a painter and it is likely that he had some radium paint in one of his boxes. Why didn't i think of this earlier? I should order some uranium ore from united nuclear and see if it is working.

Mendeleeve, if it says that it is "fission"able then it is able to be used as weapons grade uranium.

I do beleive that this had been discussed in a thread a year or so ago. if it wasn't here it must've been on science madness either way there should be plenty of links and keywords you can try.
there was an article in readers digest about this kid back in '98 or '97. probably the same basic article you have

Do you remember the exact title of the Reader's Digest post?

The old thread that covered this issue is here (http://www.roguesci.org/theforum/showthread.php?s=&threadid=579&highlight=merit+badge). It has the whole Harper's magazine article cut & pasted into it.

The amount of fissile material created by Hahn was of the order of atoms and certainly not detectable. If you want detectable, there are ways over long periods of time and multikilowatt accelerators, similar to the fusor people which uses only unrestricted materials. If you want visible, and this is still orders of magnetude below what youd need for a bomb, youd be talking of a multimegawatt facility running for long periods of time. If you want enough for a bomb, its almost a reactor or nothing, and these only come in 1 size for obvious reasons and require very expensive heavy water, or very very pure graphite (artificially produced specifically for reactors). At somepoint I will run some numbers for amount of fissile material produced per unit time/cost for several methods 'possible' at home.

Treat the artical for what it is, a tall story loosly based on actual events.

Whoops, I didn't notice this article posted in the other post, I searched, still though... I still think if the radiation was detectable five doors away through concrete that this kid must have had something. I think you can get enough U-233 if you have tons of camping lanterns, with a radium neutron gun.

I think that kid and everything he owned were mildy contaminated to the point where he was probably detecting the crap he was personaly contaminated with rather than his facility.

Definant possibility, but arn't geiger counters sensitive to direction? He was definantly contaminated though. United nuclear sells an americum source, has any one purchased one of these? they arn't going to have much in them but they would work for a neutron gun wouldn't they? I can get smoke detectors much cheaper but I dont know how much more usefull the source will be.

Yeah, geigers are direction sensitive, and remember he bought a broken americium shipment for cheap.

The amount of fissle material that the boyscout had was way to small to do anything remotely destructive; however, If the accounts are true and the radation was as high as it was reported - he could have easily incorperated the package into a radiological dispertion (aka: dirty bomb) device and spread his radioactive materials over a large area causing immence disruption but little cost to human life. ( It should be noted that this would be easier than stealing any source of radation). As for any atomic device on the improvised level - it is too hard to follow conventional designs or ideas using fissle fuel, there are nations that lack that ability. Instead, what is needed is an unconventional method - that doesnt use fissle fuel (pure fusion)

For instance, the fusor is a reliable technology which produces consistant results so why can we not use something similar? Patent number 4,826,646 (created by Robert Bussard) describes a process inwhich one could create fusion with far higher efficiency than the fusor - not only that, he claims that it can achieve a powergain on the order of 100-1000 for a modest sized device. You may say it sounds to good to be true; however, the forums at fusor.net are talking about this technology, this concept has been proven to work, and the navy has given Mr.Bussard 4.9million to develope these and other similar devices - sounds pretty good now.
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[warning here comes the the theoretical part - not to sure of my theory]
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What if Mr. Bussard's device was hooked up to another wonderful device - the Flux compression generator? For those who do not know yet, the FCG (besides creating emp) can create a huge pulse of energy on the order of 1 terrawatt and above. Should this energy be coupled to bussard's fusor device huge energy gains can be expected (remember G=100-1000). It gets better though. If the fusion device burns boron and hydrogen as advertised, energy can be easily extracted through the use of a large positive screen surounding the device (this works because the alpha paricles given off by the p+B11 process are slowed when reaching the grid, thus transmitting their energy to the grid collecter). This energy, instead of being used for some useless purpose could be redirected into the fusion device to produce a denser core and higher fusion rates - and the device would produce a 100-1000 gain from this energy, and that would be redirected, and so on...
Thus from a 1 terrawatt begining the device would produce an uncontrolable release of energy. The only faults that I can immagine includes the fact that the focusing grids would vaporise after several milliseconds (process should be done by then) and since most fusors need a high vacuum too opperate - could this work without one as there would be a gram or so of fusion fuel spinning around in an area that would quickly become somewhat dense.

Another option is using the bussard fusor with deuterium in order to creat a high flux of neutrons for changing of U-238 to Pu-239. Mr. Bussard claims that use of the fusor in this fasion would be 50 times more effective than a conventional fission reactor of the same thermal output, and should this be true - a fusion reactor of about 200 megawatts would produce the same amount of Pu-239 as a fission reactor of 1 gigawatt, and that is roughly 1 kilogram a day (Source = the Nuclear FAQ). Even more interesting is the fact that a fusor of 200 megawatts would only be about 4m in diameter. Unfortunantly, I would expect this route to be dangerous and labour intensive.

An alternative route to atomic power would be fast fissioning of U-238, but thats another post :)

Well theres my $0.02 - hope its well liked

atlas#11,

I think your counter is broken! Even just sitting on a shelf, turned on, you should get a background count. In some places 80 counts a minute is common, and if you don't hear anything for a minute, your tube is duff. Certainly when we did anything at school, the background was fairly high, and the sources low, so the difference was the major thing.

Also, you get different types of tubes, that detect different types of radiation. Most tubes won't pick up Alphas, and most are not very sensitive to gamma, or certainly not the direction of gamma. Neutrons don't register on anything but the best modern ones.

If you really want to test your tube with beta particles, remember, they are just fast moving electrons. Get a CRT, power it up, then "measure" the radiation coming off it. There should be a fair bit. Failing that, get near a ioniser or other source of high voltage. You could also try your basement, as Radon is quite common, and gets trapped down there. You can search online to see what levels you can expect.

Holy shit mrcfitzgerald, that is an insane idea! :D I like it, but certainly not for the OTC chemist with a fortune smaller than Bill Gates. What I was hoping to do if I ever aquired moderate funds, was isolate numerous thorium mantles to transform them to U-233. Structure a core, surrounded by some HE such as RDX and create a wiring system which would simultaneously detonate all sides of the core. The only question is I have is how would the uranium be arranged in the core? In implosions nukes is it structured like a soccer ball with the fissile material divided into soccer ball pentagons and hexagons or is it solid? The only drawback is I would never be able to test this if I ever made it unless I decided to take a trip to the Sahara.

The problem with assembling a U-233 core is that, youve got to make the U-233 in the first place. To get any descent sized device, and Im talking like 10kt (because it gets more complex the smaller you get from this level), you must manufacture at least 4.5 maybe 5 kilograms of U-233 from Thorium - the energy requirements for this is on the order of 5 or 6 thousand thermal megawatt hours, and that is for a nuclear plant. Also, it is impossible and unwise to use a "burn rate" much above 1/500 for weapon grade material. (this means that 1kg of thorium is produced for roughly every 500kg intoduced into the reactor environment - though you could seperated the uranium from the thorium, it would entail expensive chemical or thermal processing every two days or so - and that is assuming you have a nuclear reactor in the first place.) Youve also got to watch the formation of U-232 which is a potent gamma emmiter. As for the spherical implosion, point ignition systems dont work to well, there is to much interaction between each expanding shockwave from each point - the military had to use explosive lenses (which are very hard to develope) Please read the Nuclear FAQ, an excellent reasource, which will answer all the questions you may have about conventional nukes. To sum it up, it is impossible to do anything nuclear on the cheap. However, there is a hope - you dont need to be Bill Gates to use the method described in my first post, if you read Mr.Bussard's patent carefully you would see that all that is really needed is a vacuum (10 to the -6 torr) and a polyhedral shaped electromagnet to focus electrons in the center of the device. (The electrons can be introduced into the chamber via heating coils on the inward faceing side of the electomagnet)
In addition you would need and ion injection source - I prefer a arc injection (somewhat more simple to make than some other devices.) And for the really fancy, a charged grid to gather the eletrical energy from alpha particles and redirect the energy back into the device. The idea being that the injected ions fall towards the negativly charged center and collide with the opposing ion beam, fusing in the process and releasing alpha particles which upon slowing down at the positive grid (alpha ions = +) induce a current strong enough to fuse an ever increasing number of ions. I urge you to read patent 4,826,646 for more detail.
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In really simple detail, all Im trying to do is send a really energetic pulse into something very similar to the fusor - save that it makes more energy than is put in, and instead of letting that untapped energy go - redirect it into the bussard fusor to fuse an ever increasing number of H+B11 ions. The blast comes from the vaporization of the surroundings via intense X-rays which pass right out of the device and are not collected or absorbed. Not really that complex.
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Price is not to bad, for 1-2000 dollars you could have it built (and even that is a really expensive esitmate). Oh, and should it work, It gives quite a bang for the buck - 1 gram of fusion fuel (borax and Hydrogen) at 70% burn efficiency would equal about 45-50 tons of TNT. Finally you would need one FCG, but thats been discussed on the forum, and I feel Im writting a tad to much :)

Hope this helps clarify the first post!

With radiation measurements its rather hard to tell the source from random noise at a distance and if you're being interviewed by a clueless (about physics) reporter you wont labour on the uncertainty. "Yeah, I could detect it 2 countries over". Hahn wasnt interested in playing down the effect, and neither was the reporter writing the artical.

There are also plenty of real effects that would explain the increase in the piles radioactivity after the radium extraction from the paint, pure alphas dont register on ordinary geigers, only the beta/gamma daughters do and these will increase with time following the exraction. Add a little showmanship, and you got a 'breeder reactor', at least in the eyes of the readers if not yourself. Add a little self deception and you could easily believe that the reactor was actually working so that it would only be a matter of time before it exceeded the radioactivity of the paint.

The experiment wasnt done properly, and the results are questionable at best. The important thing here though is, could it actually work if it was done properly?
Pu is the easiest bet becuase it has the smallest critical mass, so we'll assume this is the product and that the correct blanket is provided to prodce this. Same method would apply for U-233, but more is needed.

Back of an envelope calc. To get a quantity of Pu that would go critical in a bomb, if not perform well, youd need about 2kg. Thats about 10 moles. To make it we need 10moles of neutrons assuming 100% capture (very unlikley, but this is the best achiveable, so we will assume it). To get 10 moles of neutrons from a radium neutron gun using the best (a,n) convertor (Beryllium), you need 300 000 moles of alpha particals (1uCi of alphas produce very close to 1 neutron a second, actual value being about 1 neutron per 30k alphas), its at this point the math, which perfectly correct on a logical basis, starts to look very silly. Assuming 3 alphas per radium total for ease of math, we need 100 000 moles of radium. Converting back, thats about 20 million grams. (this hack conversion and the one from critical mass cancel almost, so dont worry about that, we only need a rough idea anyway).

Ok, so what would 20 tons of radium cost? Well about 500 USD per mg, that works out to about 10 million million USD or 10 trillion dollers. Do we have a 'working' solution now? Well kinda. Spend 20 trillion dollers on radium (for half of it to decay in the time alloted), mix very well with Be, surround with the breeder blanket so all of the neutrons get captured and 2000 years later or so you have a critical mass of plutonium, with a 'simple' chemical extraction.

Ok, using the same bright outlook what could Hahn have been doing with what he had. A single clock is around a few uCi at the most and lets assume a bottle of the stuff could do a few hundred clocks (unlikley, but again with the optimism). That would give him a total of about 1mCi which would make a geiger scream like the four horsemen of the apolocalypse were stirfrying children on the 9oclock news. In reality, maybe 1/10th of this, maybe less.

That would have given Hahn about a thousand neutrons a sec perfectly mixed with a large molar excess of Be. Using a Be target without mixing, much much less, 10 a sec maybe? With quite a large blanket he'd be very lucky for 1% of those produced actually make fuel.

In other words, lucky though he was with his find, he was at least 20 orders of magnetude below what would be useful to anyone interested in weapons. More tellingly, the rate at which he was creating new fissionable isotopes was less than he was losing through simple decay.

Ok, I think thats enough work for a watercooler post bound for eventual deletion, so I'll give it a rest. I might run some numbers for some more likley methods, as I'm interested in what could be done, assuming you have the resources of a small country at your disposal and need nukes.

I vote we kick this to the original thread.Good work Marvin!

Yeah, okay, I just didn't find the other one when I searched.

Nice analysis, Marvin. It agrees with what I read at the fusor forum pretty well, too. I built a neutron source from americium and radium with beryllium. The total neutron activity is calculated to be about 10 neutrons per hour, give or take. I can pick up the gamma output from about 3 feet away with a Ludlum counter and a panckae detector. A cool scientific trivial item, but useless for any practical purpose. Anybody that lives in western Colorado or eastern Utah can pick up uranium ore by the bucketful by hunting old mine dumps with a geiger counter. Lots of fun.

I get a tad concerned about the whole homemade nuke thing. The theoretical concept is fine, but if any prozac-filled angry high school kid out there actually manages to get hold of decent uranium or weapons grade plutonium, viable quantities of berrylium, and decent machine tools, PLEASE dont build the damned thing near me, as all the plans I've seen on the net neglect to mention little details like the need to work in an enclosed inert atmosphere like argon, and serious filtering units and dust extractors. I've had one brush with cancer and dont feel the need for some of the more exotic varieties! :)

if any prozac-filled angry high school kid out there actually manages to get hold of decent uranium or weapons grade plutonium...

...then the FBI will hunt them down before they can do anything even remotely dangerous with them. Don't worry, we won't nuke you... :p

If someone neer you can get bomb worthy fissionable material, you have bigger problems than plutonium oxide particulates. Personally, I think you are more likley to be the only person in your street not to win the state lottery.

The plans on the net are mostly jokes anyway, some of them are even intentional.

And where do you expect to get the required critical amount (about 1 kg, to produce the flux of neutrons required to sustain an induced fission chain-reaction) of fissionable enriched uranium (U which is enriched in U-235 and depleted in U-238 - requires diffusion or centrifuging as UF6, which is hydrolysed by traces of water), or of the plutonium (mostly Pu-239, with smaller amounts of 242 and 244) which is recovered from spent enriched-U reactor fuel rods? And even if you did, you would have to machine, or melt and cast, the stuff into two hemispheres of more than half the critical mass each, which in bombs are forced together with a conventional explosive to start the chain-reaction induced fission reaction. The extreme chemical toxicity of the isotopes, even the U-238, would make this step very hazardous indeed. And I very much doubt that a Ra-Be neutron source could provide anything like the neutron flux to initiate and sustain a chain-reaction induced fission reaction in a sub-critical amount of Pu or enriched U.

Bugger.

Yeah, I didn't realize when I posted this earlier how much it would take to get a sufficient mass of U-233. The whole home-made nuke thing really is joke as Marvin mentioned. It would be hypothetically possible but you would probably have to be chemist, physicist, and engineer all in one, as well as being skilled in welding construction to make the apparati needed, and investing $10,000 in chemicals including HF, Ca metal, tertiary amines and etc. Thus some high school kid like Hahn would never be able to pull it off unless he stole 4 kg of enriched uranium from some government storage facility which is even more unlikely than purifying U-235 from the ore.

Yeah, the homemade nuke thing porbably couldn't be made by one person. but plutonium production using a huge fusor would only require natural uranium, which is quite easy to come by (compared to stuff like thorium). Hydrogen fusion (via large fusor) produces vast amounts of nuetrons, and when they hit the uranium blanket, they will fast fission causing a single nuetron to become several, which are then captured by the U238 and become plutnium239. Thus a single nuetron from the fusor is three atoms of plutonium, as well as a large release of energy. The fast fission could probably make the fusor self sustaining, no matter how poor your actualy power in to power out efficiency is for the fusor. I calculated the need for a total system efficiency of 0.325% or so to be completely self sustaining using 50% D+D and 50% D+T fusion. If pure dueterium is used, the efficiency requirement rises slightly, and the plutonium production drops a fair amount (D+T fusion nuetrons cause double the plutonium because they have so much KE), but who cares since tritium in moderate amounts is nearly impossible to some by.

As for making a bomb, a crude bomb using multiple critical masses could work fine. critical mass is determined by the nuetron MFP through the core, so if it's hollow, you get more mass without an explosion. Collapse it and it's supercritical and you get 20kT without a problem. A precision implosion system is not needed unless you want to get some actual efficiency or not use alot of plutonium.

Its the third damn time I wrote a response because of stupid Internet Explorer (Meltdown) so Ill just make it shorter:

The threat of nuclear terrorism is quite significant if a terrorist organization was to accumulate Heu. To clarify, the critical mass of Uranium-235 is 15Kg when reflected by a 10 centimeters of beryllium. Since Heu is only 93% U-235 this implies total critical mass of such a system to be 16.1Kg. To produce any significant yield far more than 1 critical mass is needed, in this case lets assume the terrorist accuire 1.8 critical masses (30Kg total). This device would contain 2.1kilograms of U-238 giving a spontaneous neutron rate of 12 neutrons a second. In order to prevent a fizzle, the device must have an insertion time of at least 1/120 second. This is rather easy as the bullet only needs to maintain 12 meters a second for a predetonaton chance of 10%. Yield 2.5 kilotons... None of the technology is exotic (except Uranium and Beryllium casting) and any group determined enough most likely will succeed. Radation hazard is negligable and the only cancer risk is the beryllium...

mrcfitzgerald,

I agree completely, if you can get over a critical mass of 80%+ U-235 a bomb is a fairly trivial piece of engineering. It wont be high yeilding, but it will go off. Toxicity of the uranium is not a problem, uranium fuel rods are polished by hand before they go into reactors, uranium oxide used to be a common pigment in glassmaking. HEU will be more active, but not enough to cause immediate problems.

HEU only has one use though, bombs. If the goverment lets this escape theyve allready lost, and they know this.

Plutonium is more of a risk becuase it isnt diluted in normal reactor use with non fissile isotopes, so its more likley a terrorist would be able to get this - if anything at all. Reactor grade plutonium is overcooked, so there are a lot of isotopes with high spontanious fission rates. This makes a high yeilding bomb much harder to make, but if you only need 5kt or so this is feasable. If a terrorist is able to get hold of nuclear material, you have to assume they can get high explosives. Using large amounts of high explosive its possible to make much smaller amounts of fissile material into a bomb, a few kg should suffice. Plutonium is vastly more toxic due to chemical and radiological effects but building a bomb is certainly possible.

In both cases its the getting or making of the fissile material thats the hard part.

No doubt getting Pu-239 is more likely, the issue with this type of weapon is the difficulty in assembly fast enough. There are several ways terrorists may actually go about doing this. This includes planar, cylindrical and spherical implosion, of these I consider planar and cylindrical implosion most likely -achieving spherical implosion appears to be simply insurmountable. For a planar system, one would simply need to mount one planar lens generator behind a cylindrical disk of Plutonium. The disk, of course, could be reflected with beryllium in order to reduce its Critical mass to 5kg. Upon detonation the shockwave could be allowed to unload over an airgap and accelerate accelerate the disk to roughly 2-3 kilometers per second. This projectile would then colide into another identical, stationary, assembly. Insertion time would be roughly 1/60000 - 1/40000 a second or: 16-25 microseconds. Effieciency would be ~0.7% yield 1.27 kilotons. Infact it may be better than this as delta-phase Plutonium will undergo transition to Alpha phase plutonium when shocked above 20 kilobars; there may be some shockwave compression too on top of that... Then again, the disk-shape requires 1.34 times as much Pu-239 so the results probably cancel eachother out. This may have been the design taken by the genie, a nuclear air-to-air missile with a yield of 1.7 kilotons and a weight of 218lbs (it may of used a U-238 tamper though, which would of increased the weight by a substantial amount). This design would, however, require weapons grade Plutonium metal -I believe reactor grade would produce an insignificant yield. Cylindrical implosion is deffinately more difficult -it appears that, while planar waves generally smooth themselves out in the prescence of instabilities, converging detonation waves do not. As such, a group would need to develope either a flying plate ignition system, or a cylindrical lensed system (the lens probably be the more difficult of the two.) Using a beryllium reflector, such a design may weigh as little as 500-1000 lbs. Yield could possibly be in the range of 15 kilotons if weapons grade plutonium was used, since this is not likely -it is probable that reactor grade Pu used in such a device would fizzle everytime at between 200-500 tons yield... Thus it seems either device would be extrodinarily difficult to manufacture, the first one requiring weapons grade type material (they may be able to purify reactor grade to weapons grade via centrifuge in as little as 10 cascade steps), the other requiring sophisticated lensed apparati. Furthermore, it seems extrodinarily unlikely for them to seperate such materials out of fuel rods (which have a surface radation dose of something on the order of 10,000 rads an hour...) Nontheless, terrorist have proved themselves .... suicidal in the past and there is a good chance for that to continue... The best safeguard is, certainly, moniter closely the flow of nuclear fissle materials and wastes. Prehaps this thread should be moved out of the water cooler, again?

Edit: See the nuclear faq on www.nuclearweaponarchive.org for further information -it is very good and provides so much more than you could ever find on the net. I also recommend "Swords of Armageddon," even though I have not read it... it appears to be the deffinitive work on nuclear weapons -a bit pricey though.

How about using a PARAGRAPH break every once in a while? ;)

NBK

Mrcfitzgerald, this is a good idea. Why not build your own reactor? A homogenous nuclear reactor would be the best bet. It is safe (it cannot melt down, I'll explain that later) and fairly easy to build. The only downside is it requires a critical mass of one pound of U-235 which is about 150 pounds of natural uranium. The purified U-235 is ground into a powder and put into water. The water acts as a moderator and this prevents a meltdown. As the water gets hotter, it moderates neutrons less and less untill it just won't moderate neutrons anymore. It also requires a carbon reflector around the reactor unit. Also you should not forget the cement shelding on the unit. In small quantities, you could get useful isotopes. For example if you run the reactor at 300 kilowatt days for one year, you get 2 grams of strontium or 111 grams of Pu-239/U-233.

Reactors require the foremost attention to detail. It seems a homogenous "boiling water" type reactor would be less complicated than heterogenous type though... I believe this was one of the first types of reactors -extrodinarily popular in the 40-50's (even fermi manufacture one after his Chicago pile types) but fell out of favor later on due to low power density... It appears that this type of reactor may be, with much effort and expense, feasible -but not for the production of any fissle materials other than gram quantities. It would serve little purpose breeding material for the bomb, instead it may find more use in the creation of tritium for boosting. A device, such as those I've mentioned above, that is boosted will produce extrodinarily high efficiencies for its given critical mass. Take for example, the theoretical U-235 device above -if it was boosted it would produce a good 20-30 kilotons instead of 2.4. Tritium, however, has a low atomic mass which makes it difficult to produce large quantities of -furthermore its half life is 3 years and as such requires constant replacement. In the given example above, it may be seen that for every year one could have 1.4 grams of tritium which just happens to be enough for a standard device (it may be possible, however, that as little as half a gram of tritium is required.)

Mrcfitzgerald, why not build a gun type device? Construction of such a device should be fairly easy. Only difficule part is getting fissile material. The critical mass of U-233 is about 16 kg and U-235 is about 52 kg. Perhaps a natural uranium tamper and some tritium for fussion boosting. Perhaps some other methods could be used to get wierd fission isotopes like thorium to U-234. An efficent gun type is fairly high yeild and fairly simple to construct.

Edit: See the nuclear faq on www.nuclearweaponarchive.org for further information -it is very good and provides so much more than you could ever find on the net. I also recommend "Swords of Armageddon," even though I have not read it... it appears to be the deffinitive work on nuclear weapons -a bit pricey though.

I have read as much as possible of the site you recommended. The site seems to be a good source of information and it led me to think that the issue of making a (thermo)nuclear device is not a simple but a very demanding task. Even if one can obtain enough fissile material, there are several parameters to be taken into account even the gun type device that majority of members deem simple. The account of "Little Boy" reflects this fact properly.

Anyway it was a good read. Thank you for the link.
P.S. It was leeched, compressed and uploaded to the forum FTP.

The half life of tritium is ~12.5 years, not three.

All nuclear weapons will be somewhat challenging to design, however, they really are easy to get working. To get a bomb to function with great efficiency is a demanding task however, and will definatly require large amounts of research and alot of techological expertise. Shooting two 40kg pieces of HEU together will create a large explosion, and hardly any skill is required to build this sort of weapon (there is more to it than that, so don't think I don't understand the work that needs to go into a viable weapon).

A spherical implosion weapon could be constructed, however, it wouldn't be a perfect implosion. But have 3 critical masses in a layered core design, and it won't need to be perfect to work well, simply because there is so much fissile material. It's crude, but it works.

Luckily, there is alot of hype out there about nuclear weapons being impossible to construct (or being incredibly simple, which is also missleading). This, combined with the fact weapons grade material is very hard to aquire in useful quantities, means that any terrorist organization is not going to put a large amount of resources into a project that may never see success due to lack of material or engineering capabilities.

The half life of tritium is ~12.5 years, not three.

Absolutely true, It was late and I must have confused it with the atomic mass somehow... Anyways, I found an interesting tidbit of information. It appears that tritium/deuterium boosting may not be required after all for the boosting effect. Test Snapper-Dog (You must really wonder how they come up with these names... :rolleyes: ) was reportedly just deuterium boosting. The design was not adopted though, as it seems deuterium/tritium boosting is far more utilized. Prehaps, the addition of a small amount of lithium-6 deuteride to the core will allow a bit of tritium breeding before fusion ignition, and prehaps a bit more fusion burn then deuterium gas alone.

I understand a fusion core to a conventional spherical implosion device will double the yeild but not much more. Much the same for using a depleted uranium reflector. For anything bigger you need a proper Teller-Ulam design.

Using 3 critical masses in a layer cake design would work, I agree. But the smart terrorist would try to make 2 bombs for his money. The way to go would be to use as a little as possible to get the comparason between Hiroshima or Nagasaki, its the news reports and the hearsay and the global fear that are the goal, not dead people or the number of zeros behind the estimated yield. This would dictate you make as many as possible bombs from however little fissile material you can find.

Part of project Orion was to develop small efficiant bombs that used as little fissile material as possible. Its application to terrorists who would probably struggle to get enough for one bomb is almost certainly why this project hasnt been declassified.

I recall one time when I was trying to locate bomb mechanics on the net when I went to a web page that teaches how to make a home made nuclear bomb. I was able to download and copy the text but the disk I saved it on got lost. Anyway, after some time I could not locate the site anymore and it was such a shame that I lost the text. But still, the author of the site cautioned if people are gonna try,it is really dangerous without proper knowledge.

I'd give you 100:1 odds the file wasnt worth the price of the floppy disk it was stored on.

None of the 'how to build a nuclear weapon' texts Ive ever read were worth the time it took to read them technically. There is a lot of infomation on Carey Subletts FAQ, and a vast amount of data on how the early bombs both fission and fusion were designed, the amount of fissile material used, the whole nine yards. None of it will talk about 'how to build' anything, only this is what has been done, this is how well it did, and this is why.

Its a matter of competancy. Anyone dumb enough to want to write a 'how to' article on nuclear weapons is automatically too stupid or too young to understand how they work. By definition the author would have had to have succeeded with his process in the past.

The only good how to articles are by people who are totally competant, want to see people do the same things they can and know they can succeed without large amounts of background information.

kreme, go back, read your post and asses it objectively. Point me out one single piece of useful information (or even opinion) that it provides. As I see it, it tells us all here absolutely nothing. Like the "how to" nuke texts Marvin mentions, your post isn't worth the time it takes to read it.

We expect a high standard of posting at this forum. Every word should be important. It is a crime to waste seconds of busy peoples' lives, and a waste of bits.

Please put more thought into your future posts.

The liH booster idea using only dueterium might not work that well now that I think about it (before I assumed, being able to assume with not building it and all, that it would work ok, but not as well as tritium and dueterium lithium hydride.) probably will not achieve enough heat before core dissambly to actually produce a notible effect. Tritium would not be produced enough from fission nuetrons in such a small sphere to cause and effect.

On the other hand, I'm sure if you actually made your own nuke, you would probably be able to get tritium easily compared to the fission core. Even with it's short half life, you could store it for several years without any noticable effects. But I would be very surprised if you stored it at all, instead of blowing something up within a few months. I don't think it would be a really big design problem compared to getting enough plutonium or uranium for the core.

I have a report from an internet company that has a story about: a dumb guy once disintegrated his house using a UV laser and radioactive material. I am wanting to know if the story is true. I calculated the yield of detonation assuming 1gm Th232 was forced to instantly alpha fission at 100% efficiecy(and my math is correct, it's been awhile since I've worked with this sort of stuff) at 1.6 Ton (not Kiloton). I am looking for a large explosion (think a truck bomb level blast) INSIDE the home of a free energy researcher.

I have a small report that states there was "a dumb guy who disintegrated his house witha UV laser" and some radioactive material. I am wanting to know if anyone has heard of a mystery explosion INSIDE a free energy researcher's home that would have been on the order of a truck bomb blast but at his workbench. This probably occured from late 80's on.
I would ordinarily discount something like this story except I also have a copy of "The Evolution of Matter" by Gustave LeBon in 1856, in which he describes tabletop experiments at making nonradioactive materials radioactive. His exact apparatus is not known except he worked with UV light from the sun focussed in lenses. He also did not work with material already radioactive.