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Nuclear Battery That Runs 10 Years
Jenny writes "A battery with a lifespan measured in decades is in development at the University of Rochester, as scientists demonstrate a new fabrication method that in its roughest form is already 10 times more efficient than current nuclear batteries -- and has the potential to be nearly 200 times more efficient. Similar to the way solar panels work by catching photons from the sun and turning them into current, the science of betavoltaics uses silicon to capture electrons emitted from a radioactive gas, such as tritium, to form a current. As the electrons strike a special pair of layers called a 'p-n junction,' a current results. I can imagine lots of applications for this new battery including my own laptop."
How does tritium affect people's health?
As with all ionizing radiation, exposure to tritium increases the risk of developing cancer. However, tritium is one of the least dangerous radionuclides because it emits very weak radiation and leaves the body relatively quickly. Since tritium is almost always found as water, it goes directly into soft tissues and organs. The associated dose to these tissues are generally uniform and dependent on the tissues' water content.
How does tritium change in the environment?
Tritium readily forms water when exposed to oxygen. As it undergoes radioactive decay, tritium emits a very weak beta particle and transforms to stable, nonradioactive helium. Tritium has a half-life of 12.3 years.
How do people come in contact with tritium?
People are exposed to small amounts of tritium every day, since it is widely dispersed in the environment and in the food chain. People who live near or work in federal weapons facilities or nuclear fuel cycle facilities may have increased exposure. People working in research laboratories may also come in contact with tritium.
How does tritium get into the body?
Tritium primarily enters the body when people swallow tritiated water. People may also inhale tritium as a gas in the air, and absorb it through their skin.
What does tritium do once it gets into the body?
Tritium is almost always found as water, or "tritiated" water. Once tritium enters the body, it disperses quickly and is uniformly distributed throughout the body. Tritium is excreted through the urine within a month or so after ingestion. Organically bound tritium (tritium that is incorporated in organic compounds) can remain in the body for a longer period.
Obliteracy: Words with explosions
special pair of layers called a 'p-n junction'
The p-n junction is sometimes called by its more technical name: the "diode".
implanted defibrillators
defibrillators are usually *not* implanted, so it's worth specifying.
nuclear decay is a completely spontaneous process. the only way to get more beta particles is to have more radioactive material. long lasting does not mean lots of power.
this reminds me of an essay I read by a second year physics student that nanotechnology would allow us to run 10GHz computers for 10 years off a watch battery. it's BS but you don't need to look at the technology to see that, it's just basic thermodynamics:
law 1. you can't win
law 2. you can't break even.
law 3. you can't get out of the game.
"As the electrons strike a special pair of layers called a 'p-n junction,..."
Those special layers are in every diode (including LEDs) in the universe.
Earlier story on slashdot about Cornell work on atomic MEMS
There's not much detail in TFA on how it works. FYI a pn junction is nothing new, it's aka a diode, and is the basis of other more complicated semiconductor structures (FETs, BJTs). Does anyone know how this works? I'd imagine it's similar to the way a BJT works. In a BJT, two pn junctions join to make pnp or npn bipolar transistors, the n or p in the middle is the base and it is a very thin layer. Injecting a small amount of charge in the base causes electrons to diffuse across one of the pn junctions (of of them is doped differently than the other). The base is thin enough that before the electrons can recombine they are swept across the other junction. In this manner you get very high current gains -- a small base current results in a much larger current in your bjt. Anyone know anymore about the battery tech in the article?
Intel transfer the difficult from Hadware to software, for get more power, programmer need more technology. -- chinaitn
They're probably pretty close to indestructable, so I wouldn't worry too much about idiots. Even if they do manage to penetrate the outer shell, the materials will probably be of a "safer" radioactive type such as an Alpha Emitter. Alpha rays are generally not dangerous as they easily bounce off the outer skin.
The primary safety hazard is actually the inhalation of an Alpha Emitter. Once inside the soft tissues of the lungs, the emitter increases the risk of broken DNA strands, thus leading to cancer. Note that this is a worst case scenario. Most Alpha Emitters are far too heavy to float in the air, and far too strong to be easily pulverized into pieces small enough to float.
Note that evidence suggests that the other concern, indigestion, is a non-issue. In all documented cases where Plutonium (a common alpha emitter) was accidently ingested, it was found to pass through the digestive tract without issue. Radiation was not an issue due to the general thickness of the digestive system.
Compare this to the safety hazards of Alkaline and other battery technologies. These technologies can easily poison water wells, are quite dangerous if ingested, have the potential to explode, and can cause serious burns when in contact with the skin.
Javascript + Nintendo DSi = DSiCade
I've heard the same thing once or twice, but this page says it's one of the least expensive radioisotopes.
This blogger comes to the conclusion that it is at least a thousand times more expensive than gold.
And here's a solid figure: the Canadian Ontario Hydro company asks about 28 million dollars (Canadian) a kilogram. Hang on, I'll get my wallet.
perl -e 'foreach(values %SIG){$_="IGNORE";}while(){}'
Disclaimer: I am a nuclear engineering graduate student.
This seems like a rather nifty extention of the technology. However, note that the fuel source, tritium, is rather hard and expensive to come by. (The total world supply of the stuff is < 40 kg.) So I see this as a great boon for, say, space probes or other fancy applications where getting your hands on some tritium gas aren't the biggest of concerns on the budget. It'd be interesting to see how they compare to other nuclear batteries that rely on heat from alpha-decay of heavy isotopes like plutonium to generate electrical currents.
As far as all the jokes about a nuclear laptop battery using this technology causing sterility, note that tritium decays via beta emission (i.e. an electron), with a range in solid materials of a few mm, so those energetic electrons will stay in the battery. Your primary concern would be if you somehow cracked the thing open and inhaled the tritium gas -- then those few mm of exposure in your lungs etc. aren't the best things to have around energetic particles. (And, as far as having to ingest nuclear sources, tritium is probably one of the better ones, since not only does it have a relatively short half-life of ~12 years, but it gets flushed out of the body rather rapidly as it diffuses into the bloodstream/water in tissues, leading to a much shorter effective biological half-life of 11 days.)
Tritium is used in a number of consumer goods, such as gun sights and watches. It is not highly regulated.
Please sign petition to restore sanity to our banking system!!!
http://financialpetition.org/
Luckily, the tritium they mention as a source of radiation doesn't give off gamma radiation, only beta rays which are high-energy electrons.
What if someone *intentially* breaks one open?
...don't underestimate the depths of human depravity
Apparently its quite a big thing in Jamaica to go around throwing car battery acid in peoples faces...
This UID is 7651 digits too high to subjectively infer IQ from.
There is another way to make a "nuclear battery", which was discussed in the september 2004 issue of IEEE's Spectrum magazine (could not get a link...): by ionizing a bit of matter, it gets attracted to other matter (think static electricity). So you ionize a flat, piezoelectric part that's attached at one end over an unmovable base plate. The attraction makes the loose end of the part strain down to the base, and the piezoelectric nature of the part makes it generate electricity on the way.
You're not old until regret takes the place of your dreams.
Tritium is not safe because of its casing, it is safe because it is extremely low radiation that cannot penetrate human skin
Juggle some tritium in your hands and nothing will happen to you - sleep with it and nothing will happen. Eat it or let it into your blood stream and then you are in trouble... But then again let regular battary acid into your blood strream (or ingest it) and you are in trouble there too.
I mod down so you can mod up. Your welcome.
I'm just curious. How is relevant concern about national security and these batteries rated as a troll? Obviously the moderator has never heard that the NY City police carry radiation detectors now, and that people who have had medical exams involving isotope injection for scanning have actually been pulled off public transit. Radioactive batteries *will* get law enforcement response.
There's a modest demand for tritium. It's needed to recharge H-bombs. Fusion researchers need sizable quantities of it. It's used for night lights in exit signs, watches, and gunsights. Tritium has a half life of about 12 years, so you lose 5.5% every year as it decays to helium-3. So a new product that requires tritium faces a major supply problem.
The hazards of tritium exposure aren't high, but some precautions are required. Cleanup procedures for a broken tritium exit sign are as follows:
When an Exit Sign Containing Tritium (3H) Is Damaged (broken with the release of 3H):
The protective clothing required for cleanup usually consists of gloves and booties. The broken sign should be placed in an air-tight container by a health physics consultant. If silica gel is available it should be placed in the container with the broken sign. The silica gel will collect tritiated water. At a minimum, the broken sign and any miscellaneous pieces should be double bagged and sealed in plastic. Disposal of the broken sign should be arranged through the manufacturer or a health physics consultant.
And people screw up, even with ordinary exit signs. Here's a Nuclear Regulatory Commission report from 2004:
USAF personnel in the Johnston Atoll in the Pacific were attempting to remove the "batteries" from an exit sign they believed to be battery powered. During the attempt to open the case, they destroyed the sign only to discover that it was a tritium sign. All tritium modules were broken.
Five personnel were in the room at the time and all were potentially exposed to the tritium. The Radiation Safety Officer (RSO) isolated the room and the personnel clothing, etc. Pre-cleanup surveys indicated greater than 6 times the normal background survey readings in the room. The RSO double-bagged the sign and tritium module debris. The room and work areas were decontaminated. Post-cleanup surveys indicated normal background readings. Personnel uptake and dose evaluations are currently being assessed.
So, like the nuclear batteries of the 1960s, this will be a specialized technology of very limited application.
Meltdowns and prompt-criticality have nothing to do with each other. A meltdown occurs when the heat generated in the nuclear fuel is not removed quickly enough such as during a loss of coolant accident, and so the fuel actually melts. Prompt-critical is when the reactor is critical* on only fission neutrons**.
*The term critical means that the reactor is producing as many neutrons as are being absorbed or leak out. In other words, the power level is constant. Sub-critial means more neutrons are being removed, and so power level decreases. Super-critical means more neutrons are being generated then removed so power increases.
**Normally, the reactivity of a reactor is controlled on delayed neutrons, or neutrons which are created by fission products tenths of seconds after a fission occurs. Fission neutrons are generated within microseconds of fission occuring. When a reactor is prompt-critical, it is extremely difficult to control because the time between neutron generations is very small, and so the power can almost instantly jump to very high levels before any sort of control system can respond.
and btw, IAANE.
http://www.bellona.no/en/international/russia/navy /northern_fleet/incidents/37598.html
whatever the material is in old smoke detectors
The isotope you are looking for is Americium.
http://blog.nexusuk.org
In terms of increasing amounts of information (least to greatest):
http://en.wikipedia.org/wiki/David_Hahnl b .html
http://www.dangerouslaboratories.org/radscout.htm
http://laplace.physics.ubc.ca/Students/borthwic/r
Could a battery such as this be turned off?
No. Excess energy would have to be expended in some form or another. Perhaps a small motor would be installed into the battery, and the power diverted there in case of a surplus.
If not, a laptop seems a poor use, but a tiny one might be great for cellphones.
Cellphones have always been the place that I have suggested the first batteries be made for. Besides lower power requirements, people have far more trouble keeping them sufficiently charged. But once that's tackled, there's no reason not to power laptops. Especially since many modern laptops (e.g. Macintoshes) rarely get turned off. (In the case of Macs, you just close the lid and the laptop goes to sleep. A pulsating LED on the front tells you it's state.)
Javascript + Nintendo DSi = DSiCade
Could we use this technology around existing nuclear reactors? They're already throwing off a ton of radiation, beta and otherwise I would imagine.
If it's more efficient than using fission to boil water to spin turbines that generate electricity, then it would be a great idea.
But after looking around the web, I don't think it is.
"I don't know, therefore Aliens" Wafflebox1
The beta radiation from tritium won't even penetrate the outler layer of dead skin cells on your body. It's that weak. Nothing would get out of the battery to trip any detectors.
You have to eat huge amounts of it to get any harmful doses.
See : http://www.physics.isu.edu/radinf/tritium.htm
Depends. Both U-235 and Pu-239 decay via alpha emission, which is easily blocked by almost anything. The risk for detection is beta, gamma, and neutron emission, which the daughter products can release. U-235 is especially bad because not only is its half life 30,000 times slower than Pu-239's, but the principal gamma radiation released in the decay sequence is low energy (a millimeter of lead should be enough to shield most of it).
Purity is important, of course. Your typical reactor-grade plutonium has sizable amounts of Pu-240, which is a lot more detectable. Likewise, if the uranium wasn't created with the intent of making it smuggled, it probably has contamination of U-232, which has a very high energy daughter product decay that wouldn't be realistic to shield. There have actually been proposals to deliberately contaminate all uranium produced (to the extent that international cooperation allows) with U-232 to make smuggling unrealistic.
Stale pastry is hollow succor to one who is bereft of ostrich.
Well, troll is a little strong I think, the concern is valid but should be alleviated with some background knowledge :)
These batteries won't be detected by radiation detectors, anyway. No pulling you off public transport for that.
Not only will the weak beta radiation not get out of the battery, even if the battery does leak, you can pour millicuries of tritium all over detectors, be it badges or geigers or whatever. The weak beta radiation won't even develop film.
Now, medicinal doses of I131 or wahtever- those show up loud and clear. I had a friend who had to have his thyroid zapped- he pegged out lab geiger from 5 feet away.
Weak beta emitters like tritium that are really almost no concern- I'd like it if they were more dangerous as then you can monitor them more easily (they show up on things like a geiger).
The onyl way to "detect" weak betas like tritium is to mix it with some other substance that glows just a tiny bit when hit with low energy beta particles, and then load it into a special very sensitive machine to look for that emitted light.
All that said, I'd like to know if they are loading their battery with millicurie quantities or what- if it leaked, that could be an ingestion hazard. I've not RTFA to see though :)
HTH.
HTH.
>The only way to "detect" weak betas like tritium is to mix it with some other substance that glows just a tiny bit when hit with low energy :)
---------
Actually you can get special types of handheld counters for looking at tritium. I was typing too fast
The distance a weak beta particle can go in air, though, is 1/6 of an inch.
Not very useful for scanning (as in our public transit example), as a result.
Its a shame Physorg failed to mention that these generate about one-thousandth the power of a chemical battery, making them quite useless for most all consumer electronics devices that are remotely power hungry. See the press release.
The small amount of tritium in the battery would quickly float to the ceiling, or out into the atmosphere. The beta radiation released from the tritium is of such low energy it literally would be stopped by your outer skin cells. No damage could result from this...
Heavy yes, but not as hard to make small as one might think. Certainly small enough to lug around in a car trunk.
Here's a link to the Davy Crockett recoilless rocket launched artillery, at 0.01 kilotons it's not a big nuke. But sure as hell would raise the hackles of the US Govt. and scare the crud out of whole states full of people (aside from the ones killed outright).
This was back in 1961. Since then, there is probably little point in making it much smaller, rather making it have a higher yield. I wouldn't be suprised if there were warheads this size with 10 times the yield of this one available now.
The Register has an article about how radioactive tritium "glowring" keyrings cannot be imported into the US since the authorities have placed an embargo on the civilian use of radioactive material.
More details on Tritium.
Given these restrictions, we probably won't have nuclear powered laptops, but it will help make space probes lighter.
Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
yes, we can. the problem is that to do this you need to reprocess the material and the US doe snot reprocess it. even though reprocessing it reduces the radioactivity of the material to much safer levels, so you could simply reprocesses it and transport it if you do not want to recycle it for energy.
I am the Alpha and the Omega-3
found it here:u m.html
http://www.science.uwaterloo.ca/earth/waton/triti
This space is intentionally staring blankly at you
you can pour millicuries of tritium all over detectors, be it badges or geigers or whatever.
:-)
No, only if you're using a gamma-only geiger tube. Any alpha-capable geiger tube detects tritium fine. My pancake geiger (as well as my beta-gamma scintillation probes) goes nuts from the tritium of those glow capsule (used in compasses and keyrings) though the glass capsule it's sealed in. You're right in that you need to get the sensor so close that it's not going to be an issue on public transport, but it definitely sets off standard sensors.
I can't remember if I ever tried it with a beta-gamma geiger tube, though I imagine the "thin wall" isn't thin enough
chl