On 4/9/06, Aaron wrote: <Snip> Actually, I may have misspoken that Cherenkov radiation is gamma radiation per se, because I think that distinction falls specifically to that which results from nuclear decay. Cherenkov radiation is E-M radiation caused by the sudden deceleration of particles when they reach a medium for which the= y would be exceeding the speed of light. For a nuclear reactor, this can sometimes be seen as a blue glow when the particles leave the metal and reach the water, causing them to instantaneously decelerate and emit E-M energy. This looks really cool by the way; its an eerie blue glow. I'm not sure if any of the radiation particles can be considered better/worse than another. Beta radiation (electrons and positrons) are shielded by clothes and alpha radiation (helium nuclei) is shielded by skin= , which is good. However, eating an alpha/beta source can be pretty damaging though because the energy is dissipated in a more concentrated area in your GI tract for example. But cooking something with any of these wouldn't really do anything to the food itself but heat it up... Neutrons would be = a different story because they might activate something in the food and make the food a source itself. -- Homer Simpson hay.steve -AT- gmail.com Barry Paradox: Consider k to be the greatest element of the set of natural numbers whose description require maximum of 50 words: "(k+1) is a natural number which requires more than 50 words to describe it."
But that's the thing steve. alpha and beta, are technically particles... ie matter.... you probably could not cook very well with them without them actually touching the food, ... which would leave umm err...'halflife' behind.... gamma is energy, ie a ray, so would not leave a particle to be ingested. but given it's penetration power... would it even slow down enough in the food to actually impart any significant heat? lets just use them to heat the sodium in the primary coolant loop, and run the sodium around a cast iron pot to heat the pot to transfer the heat to the beans.... the iron will also shield the beans from the particle radiation as well... so ok yep... nuke reactor works just great...... now to find the phone number to GE's spent fuels division Aaron
Aaron wrote: <Snip> I don't think that any of the fast breeders are working any more. Man, a liquid sodium loop is a tricky thing to handle. Its got this thing for water..... <Snip> -- There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states that this has already happened.
No, no no. Not good. You're back to conductive heat. LOL Rube Goldberg for the nuclear age. Gotta love it. On 4/9/06, Aaron wrote: <Snip>
On 4/9/06, Aaron wrote: <Snip> An alpha particle is only a highly energetic helium nucleus. Once it slows down, its just an inert helium atom. Positrons don't last very long becaus= e they are antimatter and electrons, well.. they aren't a big deal either. However, I do agree that alphas and betas would are not very good cooks. Since they aren't very penetrative, so the middle wouldn't get done! They might be good in a toaster oven though... -- Steven Hay hay.steve -AT- gmail.com Barry Paradox: Consider k to be the greatest element of the set of natural numbers whose description require maximum of 50 words: "(k+1) is a natural number which requires more than 50 words to describe it."
Steve Hay wrote: <Snip> You're right about alpha particles being uninteresting, but electrons are a real big deal. Beta particles, either directly or from gamma or x-ray radiation knocking an electron loose, form the basis for radiation induced mutations and cancer. --rick
On 4/10/06, Richard Hoffbeck wrote: <Snip> Sure, but just like alphas, once they've lost their energy (which happens with betas when they hit a piece of paper or clothing), they are no longer interesting... -- Steven Hay hay.steve -AT- gmail.com
I thought beta could penetrate paper. From what I remember, alpha will only travel a few inches in air anyways and can be stopped by paper. beta, can travel a bit further, and can be stopped by wood, or a sheet of metal. gamma, well, you are nothing in it's path when it is really charged up. alpha will be stopped AT the skin surface, ie at the dead skin cells layer and can be washed off easily. beta can penetrate biological material (skin/flesh) to about 5mm and this can cause burns, Let's also not forget, there are two types of radiation, Ionizing, and Non Ionizing. NI radiation includes some uv, ir and visible light. It also includes microwave radiation, radar and any radiation generally in the range we call 'radio waves'. Ionizing radiation now is basically any radiation that is energetic enough to remove an electron from an atom. This will create an ion, hence the term. Ionizing radiation would consist of cosmic rays, x-rays, gamma rays, and while they are not energy, alpha and beta particles. Obviously it's the ionizing radiation we are most worried about because this can cause damage from either the heat of its creating/decay or carninogenic properties from it's altering of living cells. Radiation is found in pretty much EVERYTHING. From the air we breathe (radon) to the food we eat (potassium) to the water we drink (tritium). As an interesting side note to all of this The rate of decay of radioactive atoms (or radioactivity) in any material is measured in Becquerels - named after Henri Becquerel, who discovered radioactivity more than 100 years ago. One Becquerel is equivalent to one atom decaying every second - about what you would expect to find in a gram of coffee. http://www.awe.co.uk/main_site/scientific_and_technical/Factsheets/URR/index.html)So for those who drink a lot of coffee, guess what? Aaron
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Michael, yes I have been doing some studying. This topic got my interest and I wanted to comment on an earlier post so figured I better put my $%^ all in one sock before I speak up, lest I be lableled a troll... (well ok a bigger troll than I am labeled now heee) For what it's worth, I used to work around nukes in the Navy so made it a habit to learn all I could about radiation. I do find it interesting that the moment anyone says nuclear bomb, immediately probably 99 percent of the population says plutonium, uranium...when in theory, any radioactive material, can be brought to critical mass. It's not the mass that is important really, it's the timing.... anyways..... Yes there are beta's that are pretty 'hard', but I didn't want to get too geeked in my post and start confusing folks. That is another issue one will find a lot of. many people have no clue as to the difference between Ionizing and Non Ionizing radiation and will oft cause an uninformed 'panic' over oh say, microwave radiation, like from cell phones, when they really have no clue as to how any of it works. Also for what it's worth. Alpha travells pretty much in a straight line, but as I said earlier, is stopped easily just a few inches through air or skin, or.. pretty much anything. It's a fat slow moving particle. beta now is more of a 'spread' or 'scatter' pattern in it's emmission, it can cover more area. and can penetrate a bit harder. Yes there are some betas that are pretty fierce. Picture a baseball if you will. some are thrown by a flubber arm like me, others are thrown by nolan ryan who can do a 100+ MPH fast ball. Im my opinion Beta under normal circumstances is the most damaging radiation there is. Alpha will get stopped at the surface of your skin. Beta will get into you and THEN stop. This means that all that energy you mentioned to 'accelerate' this thing is now absorbed by your body. you will end up with burns etc, and since it is 'under the skin' you can't just jump in the shower with the brillo pad and clean it off either. Gamma now, as said earlier is a .. well.. super charged radio wave for lack of a better explanation, it is energy, not a particle ie mass to it, in a conventional sense. Being such gamma can be as strong or as weak as it's source emits. Think of the strength of gamma as like a voltage. You can have low voltage, or you can have a super high voltage, as in a power plants transmission lines. BTW I got some really cool movies of a 500Kv interrupter/breaker failing if you are interested. You mentioned that these beta's are being more and more of a concern to the radiological field of medicine. I believe that as the years go on and we learn more, you will find more and more stuff becoming an 'area of concern' This is really wild what I am going to tell you next. My dad used to work for a paint company LONG ago, Martin Senour Paints.... we are talking back in the 40's 50's. anyways, one of their campaigns was.. they gave out pencils... in the top of the pencil, it was a clear plastic tube with powder in it. The pencil said on it's shank.... Actual sample of uranium ore.... the start of atomic power..... plugging the tube was the rubber eraser. Anyways, this was a no sh***er sample of uranium ore. I remember bringing one to high school one day in my honors chemistry class, and we opened the thing up, and poured a few grains into a cloud chamber, crudely made with plastic dishes, and a bowl of CO2 ice, anyways... yep this thing was really spitting alpha's and some beta's in there... some of the beta's popped fairly hard they did. I have a couple gross of these pencils somewhere, i have to remember where I ended up storing them. My point being here, back then we knew pretty much nothing about radiation and elements etc. They put the stuff in a friggin pencil for gods sake. Can you imagine something like that today? OMG every tree hugger within 10000 miles would be protesting!! As time goes on, I am sure you will see some more umm... guidances... concerning radiation.. As for the X ray aspect of it, yes the very nature of the machine will expose folks to x rays..... the rotating berrylium element will scatter some, but in reality, probably close to 90 percent of the energy hitting it is dissipated as heat. The beta's I dont see as much of an issue for the operator of the machine so much, they are hiding behind the panel, but possibly the person being x rayed, as since beta's tend to 'spray' and are not a tight beam like the x rays are directed... they can miss the lead apron and go places not intended. Ok, I went on long enough here. thank you for your reply Michael, I really enjoy when I can have a fairly intelligent conversation with someone... even though it is OT and yes we will probably suffer the frownings of the puritans on the list. Take care everyone. Aaron
On 4/11/06, Michael Dhabolt wrote: <Snip> That doesn't surprise me much that Betas in particular are being looked at more carefully. I misspoke that betas could be shielded by paper. Still, one good thing about both alphas and betas is that alphas and betas both ar= e pretty easy to shield, so people tend to care most about gammas for things like shield design and the others only enter into the picture in a nuclear reactor if maintenance or something is being done. Still, I don't believe there would be any problem with using betas to cook anything ( as long as its not your body ) because the thing you are cooking isn't going to give you cancer when you eat it just because it was exposed to beta/alpha... Am I missing a key point here? I prefer the unit Curie instead of Becquerels because it makes the radioactivity seem so much more small.. -- Steven Hay hay.steve -AT- gmail.com Barry Paradox: Consider k to be the greatest element of the set of natural numbers whose description require maximum of 50 words: "(k+1) is a natural number which requires more than 50 words to describe it."
Steve, <Snip> No - you're not. Mike (just plain)
Aaron wrote: <Snip> In the current model of radiation induced cancer initiation, betas are pretty much the whole game. As they move around they produce single and double strand breaks in DNA which the body has to repair. That said, the general consensus is that radiation is a strong mutagen but a poor carcinogen. We evolved in relatively high background radiation so the body is pretty good about repairing the type of damage produced by free radicals. There are groups who have built 'guns' that can fire single electrons into a single targeted cell that should provide a lot more detail on what goes on in a cell when its hit with a beta particle. If you look at the long-term follow-up studies like the A-bomb survivor study in Japan or Chernobyl there isn't much there, and if you look at badge dose data for today's radiation workers they'll get higher exposures from natural sources like gamma/x-rays from the sun than they experience at work. BTW, the occupation with the highest radiation exposure these days are airline crews. <Snip> In the 40's and 50's radiation was the new wonder drug. It was routinely used to treat things like eczema and ringworm. Stuff that would make us cringe today. Although, keep in mind that Tesla like to read with an open x-ray source behind him because he said "it made his brain feel warm" and he died from a stroke at 88. <Snip> I work on a study that tracks the health of a large cohort of rad techs. Prior to the latest 10-year follow-up survey we conducted a focus group to make sure the questions would adequately capture the exposure histories of the oldest, and presumably highest exposed, members of the cohort. Some of their stories were absolutely mind boggling - like the broken window in a control booth that was replaced with standard glass instead of leaded glass. The mistake was found 10 years later when they tore the room apart to upgrade the equipment. --rick