[Knoss]

Quote:

My next pacemaker is gonna have one of those 30 year babies.

That would be a good use for this technology. The first transisters and semiconductors were in hearing aids.

[torontomortgage]

Streaker wrote:

Sounds too good to be true...

right, and if it IS true, then it will not be for everybody because like every breakthrough, it will cost a lot so it will be "cool" to have one.

[Knoss]

Quote:

right, and if it IS true, then it will not be for everybody because like every breakthrough, it will cost a lot so it will be "cool" to have one.

probley for five years at most. Of course if enough practical uses are found for this technology and if it can provide a practical alternitive to oil then there will likely be a faster change over.

[Winnipegger]

About time!

Fear of anything with the "nuclear" word has resulted in some people running about and thrashing themselves with mistletoe branches. Reality is it's like any other technology, powerful if you use it right, dangerous if you misuse it. A car is very dangerous if you drive at highway speed through someone's living room window. Nuclear is the same.

Although neutron radiation is infectious (causes things it hits to become radioactive) and penetrates quite deeply, other forms of radiation are quite safe. Beta radiation is a high speed electron, can be stopped by a single sheet of paper or your skin. Alpha radiation is a little stronger but can be stopped by a single layer of aluminum foil. Since electricity is moving electrons in a conductor, it only makes sense to use high speed electrons as the energy source. Basically you just need a diode to ensure electrons accumulate on one side, then they have to pass through the circuit to get to the other. The beta radiation emitter will become positively charged as it spits out electrons and converts neutrally charged neutrons into positively charge protons. The atom will move up one position on the periodic table and require an additional electron in it's electron cloud to counter the additional positive charge in its nucleus.

Actually, paper is made of organic materials, primarily carbohydrates like cellulose and lignin. Carbohydrates are composed of carbon, oxygen, and hydrogen; all light elements. Protein also has nitrogen, another light element. When radiation hits them it is slowed gently, not splitting atoms or splitting high speed ions into multiple particles, so it's ideal to shield beta or ion radiation. Some plastic is also composed of those same three elements, specifically polyethylene and polypropylene; a NASA funded study has already shown polypropylene (PP, plastic recycling number 5) makes great radiation shielding.

Batteries should be light, so you want a radioactive element that's light. Ideal is to find something that won't be incorporated into human biology, so radioactive carbon, oxygen, hydrogen, or nitrogen is a bad idea. Magnesium doesn't have a radioactive isotope with a half-life greater than 21 hours, so it won't last. Aluminum-29 half-life is 6.5 minutes, but Aluminum-26 (represented as 26Al) half-life is 710,000 years. That's quite a jump, longer half-life means less radiation. You want something that will last a reasonable time but also produce significant beta radiation. Silicon-32 (32Si) half-life is 160 years, which means after that many years it will produce half as much radiation and half of it will be decayed. It decays into phosphorus-32 which has a half-life of 14.28 days beta decaying into sulphur-32. That is a non-radioactive natural isotope of sulphur. The decay of phosphorus means you get 2 electrons for every atom of 32Si you start with, and the relatively short half-life means it produces that second electron about as quickly as it's produced.

Or you could use cobalt-60, which is heavier than silicon but has a half-life of 60 years. It beta decays to nickel-60 which is a naturally occurring non-radioactive substance. The shorter half-life means you need 60/160 as many atoms for one decay per unit time. Since phosphorus produces a second beta particle that becomes 60/80 as many cobalt-60 atoms as silicon-32 atoms for the same beta radiation. Cobalt-60 has a mass of 59.9307884 grams per mole (a certain number of atoms), while silicon-32 has a mass of 31.974148 grams per mole. Multiplying: 60 * 59.9307884 = 3595.847304, and 80 * 2557.93184, so the mass ratio for a fixed number of beta particles per unit time is 3595.847304 to 2557.93184, or 1.4057635 to 1. That means a silicon-32 battery will weigh less than a cobalt-60 battery for same initial power, and since silicon-32 has a longer half-life it will last longer.

So how do you make this stuff? Cobalt-60 is one of the waste products from nuclear reactors. There should be some silicon-32 in that waste as well, just less of it. You can also expose silicon-30, a naturally occurring non-radioactive isotope, to moderated neutron radiation to become silicon-31. That has a half-life of 2.62 hours so keep it exposed to neutron radiation to become silicon-32. If 31Si decays before it becomes 32Si, it will become 31P which is the naturally occurring non-radioactive isotope of phosphorus. If 31P absorbs a neutron it will become 32P, which beta decays to 32S in 14.28 days half-life.

(Uber science nerd and proud of it. This stuff is fun!)

[Winnipegger]

The article mentions "a porous silicon material is used to collect the hydrogen isotope tritium which is generated in the process". Why would beta decay produce tritium? Tritium is hydrogen 3, it requires neutron capture to convert deuterium to tritium; the radio isotope produce beta radiation not neutron radiation. A small fraction of natural hydrogen is deuterium, but why would tritium be a product?

One explanation could be they are using tritum as the beta emitter. It produces beta radiation with a half-life of 12.33 years. That means it would produce half as much power after 12.33 years, half again after another 12.33 years, and half again after yet another 12.33 years. So after 24.66 years after manufacture it would produce 1/4 the power of a new cell, and after 37.32 years it would produce 1/8 that of a new cell. Tritium has atomic mass 3.0160492675 grams per mole, while silicon-32 is 31.974148, but the half-life limits battery life.

Besides, if they do use tritium, its waste product would be helium-3, a non-radioactive naturally occuring isotope. Only 0.000137% of helium by volume is 3He, but it is natural. If they start with tritium they easy compound is di-tritium oxide, also know as water. It would be heavier than heavy water, but still chemically water. You could chemically combine tritium with carbon to form polyethylene, making it a solid and avoiding any problem with human metabolism picking up leakage. Helium-3 is non-radioactive and natural so you could just vent it.

The only "porous silicon material" that I could see picking up tritium would be silica gel, the same stuff used to keep electronics dry. However that absorbs moisture, again implying di-tritium oxide (really heavy water). The problem with tritium is short battery life.

[Knoss]

What about putting these batteries in all TV's refrigerators, LED lights, radios, microwaves any appliance. We could end residental electrification, we could close down most of our powerplants and sell the few smaller ones to companies such as steel mills, mines and aluminum smelters.

You cut power to your house, plug in LED bulbs with atomic batteries in the sockets and turn the on off or dim with a remote control.