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Ask Slashdot: Advice On a DIY Neutron Beam? 117

Max Littlemore writes "I have been breeding at home using lots of old smoke detectors with a view toward generating my own and getting off the grid. The only thing stopping me is a reliable neutron beam. Given that all the equipment I'm using is re-purposed kitchen equipment, concerns about safety mean I'm to build a uranium reactor to supply neutrons to the thorium one. So I'm putting the question out there: do any Slashdotters know of a way to make a powerful neutron beam out of things I might find around the house?" It would be helpful to include images and diagrams of your own personal neutron beam .
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Ask Slashdot: Advice On a DIY Neutron Beam?

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  • Sad day (Score:5, Funny)

    by Locke2005 ( 849178 ) on Friday April 01, 2011 @04:47PM (#35690606)
    It's days like this when I really miss "OMG!!! Ponies!!!"...
  • by Anonymous Coward

    Not sure, but when you get that beam working, could you point it at whoever is in charge of the Slashdot April 1 thing?

    High intensity neutrons would sterilize them perhaps, preventing them from reproducing. What we really need is a "subtlety beam".

  • by Anonymous Coward

    i don't really know why exactly but this drop down menus are lots of fun :))

  • by Oxford_Comma_Lover ( 1679530 ) on Friday April 01, 2011 @04:54PM (#35690636)

    A DiY neutron beam? Sure. Give me three coconuts, a piece of string, MacGyver, and your bank account numbers.

    And OMG Ponies. Please, for the love of God.

    PS - Act now and I'll sell you the Brooklyn bridge at a 12% discount.

    • Give me three coconuts, a piece of string, MacGyver, and your bank account numbers.

      That won't work what you really need are two palladium plates, some water and a battery to make your own cold fusion reactor which is an excellent neutron source and should work well for powering your thorium reactor. However please don't tell al Qaeda because you know they'll just start making plutonium from all the depleted uranium NATO occasionally supplies them with.

    • "Give me three coconuts, a piece of string, MacGyver, and your bank account numbers."

      Where'd you get the coconuts? The coconut's tropical! This is a temperate zone.

  • by f8l_0e ( 775982 ) on Friday April 01, 2011 @04:55PM (#35690642)
    under the boiler for steam turbine. You'll literally have energy for the rest of your life, and as a side bonus you'll be permanently reducing your carbon footprint.
    • I would think that this method would eventually increase your carbon footprints when your ash is tracked all over the place by the maintenance crew.

    • Light a man a fire and he's warm for the night. Set a man on fire and he's warm for the rest of his life.

  • by localroger ( 258128 ) on Friday April 01, 2011 @04:56PM (#35690656) Homepage
    Disguise your rig as a powerful cement pump and ship it to Fukushima Prefecture, Japan. They will be glad to irradiate it for you.
  • by Tackhead ( 54550 ) on Friday April 01, 2011 @04:56PM (#35690658)

    "I have been breeding [thorium] at home using lots of old smoke detectors with a view toward generating my own [electricity] and getting off the grid. The only thing stopping me is a reliable neutron beam. Given that all the equipment I'm using is re-purposed kitchen equipment, concerns about safety mean I'm [hesitant] to build a uranium reactor to supply neutrons to the thorium one. So I'm putting the question out there: do any Slashdotters know of a [safe] way to make a powerful neutron beam out of things I might find around the house?"

    You don't need a uranium reactor to generate neutrons (although if you use the thorium from some lantern mantles, you could probably create one). You also don't need to be messing about with nasty americium to breed plutonium as a neutron source.

    Just build a Farnsworth Fusor [] like that guy on Slashdot did last week. There's your neutron source. Should be pretty safe, compared to the alternatives.

    It would be helpful to include images and diagrams of your own personal neutron beam [beer].

    Right, that doesn't solve the problem of your neutron beam beer.

    Put a bottle of Pu240 Weapons Grade Ale [] in front of your Something in there'll get activated for just long enough to technically call it neutron beam beer.

    At 8% ABV and 100 IBUs, it's a hop bomb that'll getcha bombed even without neutron activation!

    • by Kazymyr ( 190114 )

      The Farnsworth fusor is real, despite today's date.

      Actual plans at

      Good luck. Keep us posted.

    • There's many drinks you'll drink, me lads, on every world that's new.
      There's Saurian Brandy, Cranapple Schnapps, and a good old Tullamore Don't.
      There's Busch and Beck and Bud and Bock and others dark and pale,
      But I think you'll find the finest kind is Three-Oh-Seven Ale.

      Three-Oh-Seven Ale, me lads, Three-Oh-Seven Ale,
      The finest drink that any bar has ever had for sale,
      It'll lay your whole damn world to waste, it'll make you fit and hale,
      There's nothing that you'll ever taste like Three-Oh-S
    • I found this video. Got $ 200M USD to spare for solving the world's problems? []

    • An IEC (Farnsworth Fusor) would be a good place to start for the neutrons but you will need fuel. The poster seems keen on doing everything himself and breeding fuel should be no exception. I recommend starting with Deuterium and working your way up to breeding tritium. You can buy deuterium easily enough, but everyone knows that path is for chumps. I would say you should get a good centrifuge cascade going and start separating heavy water out from the normal stuff that comes right out of the tap. With

  • by formfeed ( 703859 ) on Friday April 01, 2011 @04:58PM (#35690670)

    You could just ask your neighbor. Most high school kids who are even remotely interested in science already have a neutron source [] in their basement. Borax, you get in the laundry aisle and as moderator I suggest to go with pencils. Graphite is a well documented moderator and has worked in Chernobyl for many years without a problem. You could use tea-lights for shielding, but imho shielding is for sissies.

    Just one warning: As in banking, the important thing is to start big. If you build a small reactor, the police will come knocking down your door, but if you build a really big one, your local congressman will help you to find a way around stupid regulations.

  • by BlueParrot ( 965239 ) on Friday April 01, 2011 @05:00PM (#35690678)

    This is probably a joke or troll, but since there actually have been morons trying to do this sort of thing before:

    If you do not have enough knowledge and experience with radioactive materials and radiation safety to know how to generate neutrons, attempting to do so is a Bad Idea (TM). Neutrons are very penetrating and hard to shield against, and when absorbed they activate the material they are absorbed in, creating secondary radiation hazards. Using them to irradiate fissionable isotopes, like thorium or uranium, is an even more insane idea since it will not only multiply the number of neutrons generated, but also produce a dirty mix of fission products, many of which are gaseous and hard to contain.

    Seriously, just go do something safer instead, like base-jumping or sword-swallowing.

  • If you hit the thrift stores and scrap off the glow-in-the-dark paint from pre-70's clocks and watches you can start to collect the needed radium for use in your breeder reactor. Let me know when you've collected at least 28 grams. Then we can start construction of the reactor using an old pickle crock and a washboard....
  • Here's the recipe (Score:4, Interesting)

    by Kupfernigk ( 1190345 ) on Friday April 01, 2011 @05:07PM (#35690702)
    Take approx. 2kg of sifted weapons grade plutonium (this is perfectly safe, it's sub-critical) and place in a mixing bowl. With a mortar and pestle grind together about 5g of polonium-210 and 10g of finely powdered beryllium. Gradually stir in to the plutonium until the mixture begins to get warm, then add about 500cc of deuterium hydroxide. Divide equally into a 12-portion muffin dish. Decorate with thorium oxide granules and bake in a suitable containment vessel until red hot. Serve on a bed of fuel pebbles with a cesium iodide dressing.
    • by Kazymyr ( 190114 )

      Cesium iodide - the breakfast of champions.

    • I find that's way too much work in the busy morning, I prefer my "instant neutrons". Just take an empty 2lb. instant coffee can, put in 5 lbs. finely divided u-235, fill remainder with heavy water, put on the plastic lid and shake vigorously for ten seconds. Presto, I love a blast of neutrons in the morning. If it gets too hot just put in a couple tablespoon's of Borax.
  • by SMoynihan ( 1647997 ) on Friday April 01, 2011 @05:08PM (#35690712)

    All you need is a whole load of Sellotape (Scotch-tape for you Americans) (and some deuterium).

    Everyone (well, Slashdot readers) knows that peeling Sellotape produces x-rays [], so get some industrial sized sheets of Sellotape, probably at least a few layers. While peeling, aim your Sellotape at some material why only needs low energies to induce a photonuclear reaction (deuterium, beryllium perhaps).

    Some might say that those might need gamma rays, but those are only high energy X-rays, so shake your Sellotape fast, and you'll increase the frequency nicely.

    And voila: Neutrons!

    The rest is just details

  • by smellsofbikes ( 890263 ) on Friday April 01, 2011 @05:10PM (#35690722) Journal

    Just build a cyclotron. They're quite easy to make, being basically a huge magnet and a curved track in a vacuum. There is a minor technical challenge that they're designed to accelerate protons or electrons, but I'm sure it's easy to adapt it to handle neutrons instead.

  • by Ceriel Nosforit ( 682174 ) on Friday April 01, 2011 @05:12PM (#35690730)

    It's really difficult to get voltage that high from household equipment. To make your own beam target you will also probably need to build a CVD chamber. [] []

    But this looks interesting too: []

    • No, it's trivially easy to get high voltages from household stuff, your house already has 220 volt AC power readily available you just need several really big transformers in series to finish the job. Be sure you space the wires far enough apart that they don't arc at the higher voltages. Thick braided copper wire is prefered. Don't forget to use big circuit breakers to run the whole mess as you will have some losses in the circuit. Ensure nothing comes close to the transformers/wires during operation.
  • You might consider a neutron spallation source. Just dig your proton linac out of the attic, and fire it up pointed at a high-Z target material. I like tungsten for the target, but you could also go with plutonium if you've got some handy. Bingo, spallation neutrons galore! It's not a beam source, but if you put the spallation target near the thorium, you should be able to get the neutrons to where you need them. Just remember, safety first --- be sure to wear safety glasses and have a couple kilotons of ir

    • by Kazymyr ( 190114 )

      How many Space Shuttles can your attic hold?

      BTW here's an idea. If you send your rig in close orbit around the sun, it's bound to catch a few of those fusion neutrons.

    • by dargaud ( 518470 )
      The original question is exactly my line of work ! You can't make a neutron beam (they are neutral), but what you can make is a proton beam and then fire it at a spallation target in the middle of your core to change them into neutron. It's a new type of sub-critical reactor [], but it doesn't quite fit into my basement. Yes, and it runs Linux.
  • I'd like to see some information about technology.
    • by ackthpt ( 218170 )

      I'd like to see some information about technology.

      What, like Oliver Wendell Jones is running for president on the Meadowcrat ticket?

      It's about time we got a cat cloner in office...

    • by halivar ( 535827 )

      If you didn't think the replies to the actual (albeit fake) question were interesting, this may not be the site for you.

  • by DrJimbo ( 594231 ) on Friday April 01, 2011 @05:33PM (#35690808)
    I understand they have an excess of neutrons and such over at the Fukushima nuclear facilities. You can probably get all the neutrons you want at bargain (turbine building) basement prices. In fact, since it sounds like you are entrepreneurial, you could probably get them to pay you to haul the stuff away. It's a mixed bag of goodies but since the fuel rods have melted down, you might be able to collect enough fissionable material out of the tons of highly radioactive water available to get your own chain reaction going, cutting out the middle man, allowing you to pass on savings to your customers. Everybody wins!
    • Alas, while the Fukushima facility has plenty of gamma, alpha, and beta radiation to go around, not to mention a glut of thermal energy, they're a bit scarce on the neutrons at the moment.
  • Do not worry that a neutron beam is hazardous. Neutrons, being uncharged, pose no danger of electrical shock. Also, they simply pass through most materials.
    • Er no, neutrons don't "pass through harmlessly", they either knock off sub-atomic particles (then keep on going) or stick and make radioactive isotopes. It's not the uranium that's making heat in the japan reactors, it's the secondary radioactive isotopes created by the neutrons.
  • by Anonymous Coward

  • I think you can find plans in back issues of Popular Science.
  • Just because Mass Effect :)

    Watch out for the spores... and the green skin!

  • by LordByronStyrofoam ( 587954 ) on Friday April 01, 2011 @05:49PM (#35690898)
    .. if you're handy with tools and your money: This solution will require you to put your thorium vessel in a vacuum chamber: Cut the end off some old but still functional 4-400A power vacuum tubes (as would be used in a surplus tube amp from the Indianapolis Motor Speedway or an old AN/SQS-23 sonar system), and put a charge stripping plate (of heavy enough copper) biased to pull the charge off the electrons, at the business end. Glass-weld the tube and plate to a flange on the vacuum vessel. Fire up the cathode, put sufficient voltage on the plate, and you're streaming neutrons.
    • by Anonymous Coward
      You're also streaming X-rays, so you'll need to separate those out and dump them someplace (like the neighbor's cat -- never liked that cat). You can thin out the target region, while water cooling the surround. Or use a small tungsten plug in the target region.

      Most designs like this operate with a grounded anode (plate), and carry the cathode and filament at a high negative voltage 2 to 3 kV at an amp or so.

      You can find plenty of power triodes on your favourite auction site -- look for Eimac and Svet
  • you need it to run Linux?
  • We really need to know more about what you need, is it slow thermals (0.03MeV) or fast (2.5MeV - 14MeV), and what kind of rates. You also don't mention beam width or necessity for collimation.

    A wheezer Penning could do 10e8 fast neutrons/s in a relatively simple and compact package. There are a bunch of designs that can produce on the order of 10e11 neutrons/s. If you're in the Silicon Valley, you can even rent time on them.

    Have you tried eBay?

    Oh, and watch out for side-lobes and activation issues
  • Neutron Beam Design, Development, and Performance for N
    item #280652726952
    Buy-It-Now: $67.52
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    TERRY JOHNSON KING The Neutron Beam Murder 1965 HB DJ
    item #140137094529
    Buy-It-Now: $5.00 []

    Thanks to tibit I found this

  • Fusors are very good sources of neutrons. But the concept of a neutron beam is pretty lulzy. Neutrons have no charge and are unaffected by magnetic fields so good luck shaping that thing. May I recommend,

    Kitten Kitten Kitten Kitten
    Kitten TTTTTTTT Kitten
    Kitten T Fusor T Kitten
    Kitten T Fusor T Kitten
    Kitten TTTTTTTT Kitten
    Kitten Kitten Kitten Kitten

    Kittens provide dual shielding for both radiation and detection, who would ever look under a pile of kittens for a nuclear reactor? Further the kittens
    • I figured kittens from Japan could serve a dual role of source and provider (of neutrons) here, but when I googled "Japanese kittens" the prices I saw were around $2000/hour.
    • by Dunbal ( 464142 ) *
      Personally I would go with puppies.
  • of David Hahn. []
  • I suggest you consider lamp mantles from camping lanterns and gas lamp posts. Much higher yield of Thorium. Then encase the extracted Thorium in depleted uranium in an asymmetric manner. Pack all this in a graphite cylinder with hundred of layers of bimetal sheet thermocouples in a massive series parallel schema. The interstitial material should be silicon dioxide and clay, but make sure it is boron free. Bop down to your local ceramics custom paint shop and borrow their kiln to "fire" the setup into one solid mass to make your own homemade traveling wave radio-thermal-generator. After testing the output of the first one, proceed to manufacture as many as required for your electricity needs. They are after manufacture virtually pollution free. (May we suggest a 1/2 inch stainless steel vessel welded closed around the individual cells, oh, and assure that you use aluminum or silver wiring and avoid copper in the construction.) You may wish to purchase your own kiln after determining the number of units you'll need and the cost of firing them outside of your own facility. Also consider a micro-controller for each cell to monitor its health and power output, as well as a small conditioning circuit to match the outputs into a seamless AC source to minimize interface issue with standard house generation, and provide minimal common failure points. As the controllers will need to be interfaced as a network, you may as well distribute the decisions across all the micro-controllers, thus ending up with a beowulf-cluster of "smartRTG"(tm)s
  • Can't you infuse it with milk from Japan?
    • Oops, posted too soon without reading the previous posts about milk, etc. Now, kittens AND milk could be the way to go.
  • Proton beam, actually.

    Ruined the joke for me I'm afraid.

    (haughty sniff)

  • But if this isn't an April Fools goof, you're an idiot. For one thing, if you have an interesting enough neutron beam, why bother with mere fission. I make mine fusing hydrogen isotopes.

    I don't know if I'm "that guy on slashdot last week" that built a fusor last week, but I am a guy on slashdot who does build fusors and other fusion devices for the last few years, and I even run a discussion board about it to help and encourage others to do so. It's not a hobby for idiots (various parts are dangerous) o

    • Hate to respond to myself, but... a few details.

      One -- you can't breed thorium into a fissionable isotope with alpha rays from smoke detectors. It takes neutrons. Slow ones give the best results. It is pretty hard to make a "beam" of neutrons, but easy to make an isotropic source. If you're going to do that, natural uranium is cheaper anyway, and not impossible to get ore (legally) from rock hounds. But refining it is illegal in most cases. And oh yes, fairly dangerous, and since you didn't know the

      • Is air conditioning even possible in theory with an off grid system? A one ton air conditioner would suck about 1055 watts. It seems like it might be doable if your array and battery banks were big enough, and if you designed your home to have extremely good insulation.

        A small geodesic dome with 7 inches of foam insulation, perhaps? And a big enough array. Maybe your air conditioner system could be a ground source heat pump system (aka geothermal) that would use a water to water heat exchanger. There w

  • If you heat up Helium sufficiently it will break down into neutrons and protons. Separate the protons with an electric charge and you're ready to accelerate them towards your target. I'd tell you one of the two methods of accelerating neutrons except then the black helicopters might come back.

"For a male and female to live continuously together is... biologically speaking, an extremely unnatural condition." -- Robert Briffault