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'30 Year Laptop Battery' is Unscientific Myth
An anonymous reader wrote to mention the wonderful news: "A research group funded by U.S. Air Force Research Laboratory is developing a battery which can provide continuous power to your laptop for 30 years! Betavoltaic power cells are constructed from semiconductors and use radioisotopes as the energy source..." Except, not so much. ZDNet's Mixed Signals blog with Rupert Goodwins explains why (as always) if it sounds too good to be true, it probably is: "The sort of atomic structures that generate power when bombarded with high energy electrons are the sort that tend to fall apart when bombarded with high energy electrons. While solar cells have the same problem, it's to a much lesser extent. There's a lot of research into making materials that don't suffer so much, but it remains a serious issue ... while it's true that a tritium-powered battery will eventually turn into an inert, safe lump of nothing much, and while it's also true that a modest amount of shielding will keep the radioactivity within the the battery the while, there's the small problem that if you break the battery during its life the nasties come out."
the nastiest came out and broke your grammar checker.
Yeah, my lap is exactly where I want to put something radioactive.
Mr. LaForge: We're trapped by the aliens!
Wesley Crusher: Wait! We only need to realize that the sort of atomic structures that generate power when bombarded with high energy electrons are the sort that tend to fall apart when bombarded with high energy electrons.
Mr. LaForge: That.... could.... destabilize the aliens death ray....!
Wesley: Yeah, just like in the academy.
Picard: Make it so.
I don't know about you ... but for ANYTHING radioactive that I'm going to be sticking on my lap I want more than a "modest" amount of shielding thank you very much.
don
all language nazi's will burne in heil!
Did an editor ACTUALLY CHECK on the facts of a story before posting?
Cue the porcine aviators...
"As God is my witness, I thought turkeys could fly." A. Carlson
Computers are useless. They can only give you answers.
-- Pablo Picasso
When I was young, before the first war, we didn't have them fancy grammar checkers or spelling checkers. When we had a paper due for our teacher, we had to look up the ASCII codes manually (most of us memorized like our multiplication tables) while punching holes in cards to feed into our mechanical computer. The grammar and spelling checker was YOU! We didn't have batteries. We had to power our computers by connecting them to mills near powerful dams. And we liked it! Then we had to manually ink our ribbon before printing. And when we went to school, we often lost our papers because it was so cold. And the roads were uphill both ways!
Get off my lawn!
*shakes cane*
the article is correct that radiation destroys semiconductor efficiency although not all "nuclear battery" designs involve semiconductors. space probes sometimes use a chunk of radioactive material that has shielding around it while the energy released is in the form of heat. this heat [temperature gradient] is harnessed by a thermoelectric materal- basically it consists of several layers of different metals that produce a voltage potential in response to a temperature gradient. the advantage in this is that you can use metal as shielding and not relatively fragile semiconductor material. although you need a radioisotope that can generate enough heat from decay to be useful- tritium's half-life is about 12 years so it might qualify, although a better solution might be a solid unless they use T2O, ditritium monoxide, which is "superheavy water"
Sigs are too short to say anything truly profound so read the above post instead.
The power demands are wildly different between a fricking SUB and a fricking LAPTOP. The power generation is also far different; subs have active fission piles, they're literally mobile nuke reactors.
Atomic batteries, on the other hand, are just storage for existing nuclear material. They generate electricity as part of the radioactive decay process, either by using the heat generated by the decay, or by harvesting the incident energy of the decay process.
Types of radioisotope batteries (like RTG's) have been used in the space program forever.
ad logicam Claiming a proposition is false because it was presented as the conclusion of a fallacious argument.
On the other hand, the Lithium in your current battery will remain deadly forever.
We at slashdot are scientists, specialists and kernel hackers. Your FUD will be found out.
A larger pool of mutants means more chance of a favorable adaptation, right?
We can't be so selfish - think of the children.
Everyone talks about evolution but nobody does anything about it.
This issue is a bit more complicated than you think.
Defense contractors are always coming up with wonderful sounding ideas that are completely impractical. For example, in 1999 a company called Stavatti presented the DoD a design for a portable laser rifle suitable for use by common infantry. The device was to be powered by...wait for it... polonium (PO-210). An excerpt from the proposal:
.75 kg in a rifle that would be subject to damage, destruction and dispersal on the battlefield.
"...To increase the energy level of the CO2 N2 He gas mixture, a Zirconium-Nickel fuel rod approximately 40cm long and 1.8 cm in diameter containing approximately 740 grams (78cc) of Polonium-210 (Po-210) is contained within, and located down the centerline of, the cylindrical gas reservoir. The Po-210 provides a thermal energy source of approximately 141 watts/gram through the emission of alpha particles via the process of nuclear decay. This energy source provides a significant power density while alleviating the shielding requirements and apparent health risks associated with gamma ray emitting radionuclides. The presence of the Po-210 in the reservoir chamber will result in the delivery of approximately 104.34 kW to the CO2 N2 He gas mixture, thereby raising the gas to a state of thermal equilibrium corresponding to an internal reservoir pressure of approximately 272.1 atm, temperature of 2173.16 K and gas density of 44 kg/m3..."
You may recall that a few micrograms of PO-210 were used to kill that guy in London about a year ago, and this company has proposed putting
The paper describing the laser rifle can be found here:
http://209.85.165.104/search?q=cache:SEji6Jn6-4AJ:www.defensereview.com/352003/TIS1.pdf+pumped+polonium+laser+rifle&hl=en&ct=clnk&cd=1&gl=us
The betavoltaic battery is nothing more than pseudoscience. It's higher quality pseudoscience than junk such as zero-point free energy generators or gravity wheel generators, but it is pseudoscience nonetheless. Every few years you see these sorts of claims about betavoltaic devices pop up again, then fade away.
Despite years of claims, no one has ever come close to demonstrating a device with the sort of power densities claimed in the article. Furthermore, the biggest proponent of betavoltaic technology is Ruggero Santilli, an infamous pseudoscientist with a litany of nutty claims and bizarre theories of physics.
If you look at the web pages of the companies that are involved in betavoltaics (e.g. betavoltaic.com or nuclearsolutions.com), you'll find that they have no physical facilities outside of a rented post office box or the home of one of the principals. None of them have any product to sell or even demo. I don't expect that will ever change.
Bremsstrahlung x-ray radiation is a problem working around high-energy beta emitting radioisotopes, such as Phosphorus-32, but not Tritium, which is a very low energy beta emitter. Betavoltaics are real, workable technology; not science fiction or junk science. Cardiac pacemakers using Plutonium-238 Radioisotope Thermoelectric Generators are also a proven, decades old technology, too, for example. Tritium is an extremely low energy beta emitter. Given this, and the very short biological half-life of water in the body, it is one of the least harmful radioisotopes around. It occurs to a very small degree in nature, and is already used in radioluminescent watches, exit signs, gunsights, keyrings, compasses and such forth. The beta emission from Tritium is so low in energy that most radiation detection instruments will not detect it - only mixing the radioactive material with the scintillation cocktail in a liquid scintillation counter is sensitive enough to detect it. A gamma spectrometer, scintillation counter, geiger counter, ion chamber counter or detector won't even notice it.
This is another of those hard to die myths that will have to be debunked over and over again. Consider:
a)Butter has a higher energy density than a laptop battery
b)The hydrogen in a cup of water, if fusioned all the way to iron, would release enough energy to flatten a city ( or power it for our entire lifetime).
c)A lithium battery holding 0 charge is just as flamable and dangerous as a fully charged one.
I think this myth came about because people figured nuclear = dangerous, and Li-ion = dangerous. In reality things are far from that simple. It is not the energy density of Li-ion batteries that cause them to explode, as an example, it is the fact that they contain lithium, which is a very reactive alkali metal. As I already mentioned, a completely depleted Li-ion battery could still catch fire, and if you pulverised it and poured water on it, it would literarely explode as the liberated hydrogen ignited.
For a car, you could vitrify an isotope like Plutonium-238, forming a very inert ceramic rod which would produce heat at a perfectly predictable rate. It would also be very safe since even if the ZOMG terrorists tried to use it in a dirty bomb, the inert nature of the ceramic would keep the plutonium contained, and as a pure alpha-emitter enclosed in a ceramic, there would be virtually no mentionable radiation release. To give you an idea of how safe such a device could be. They have been used to power pacemakers.
It would also be absolutely useless for a nuclear weapon, even if the pure Pu-238 could be recovered, since weapons need very pure Pu-239. Just the heat generated from Pu-238 would make a fission weapon virtually impossible, and the neutronic properties make it absolutely useless.
The only reasonable risk I could see from such a device would be if it was left in a very enclosed space so that the heat generated would start a fire. This is however a fairly limited engineering problem which is not unique to RTGs. Similar precautions are needed for electric heaters and engines.
Main disadvantage is the ( at present ) fairly high price of Pu-238. Producing it in quantity is a fairly complex process, and it would probably be a lot cheaper to just use regular battery electric vehicles.