Talk:Ionizing radiation/Archive 2007

NPOV tag

I added an NPOV tag to the Radiation level section because it appears that the jurry is out on radiation hormesis. I think it's important to first stress that (1) The National Accadamies of Sciences, BEIR VII report (2) The US congresses National Council on Radiation Protection and Measurements and (3) The United Nations Scientific Committee on the effects of atomic radiation (UNSCEAR) all agree that linear no threshold is the appropriate dose response model for the time being. Could there be more scientific consensious? I also think a lot of this material belongs over in the main article on radiation hormesis 0¹⁸ 20:06, 18 March 2007 (UTC)

New Radiation Warning Symbol

On 15^th February IAEA and the ISO launched NEW Radiation Warning Symbol. Here's the link:

http://www.iaea.org/NewsCenter/News/2007/radiationsymbol.html

(Old one was better imo ;p - this one looks like it says: Beware of huge fans and pirate attacks - no matter if you run away they will get ya!)

When I look at it, it appeared to say: beams emanating from a point source - deadly - flee. A lot better than a propeller blade - at least that's what children thought it looked like when they were asked.

The number of people that have not differentiated between ionising radiation and other uses for the radiation symbol (such as lasers) is not trivial and lives *have* been lost.

When is someone going to add this new symbol to the main article? Mattabat 11:20, 16 March 2007 (UTC)

this new symbol is only for big sources that could be lethal, so it doesn't replace the old one. Also, we can post the new symbol but need to know its copyright. I'm not sure how to find this out. 0¹⁸ 03:05, 18 March 2007 (UTC)

Physics request

Can we have more about the physics? I know that ionizing radiation will cause electrically charged objects to lose their charge. I think because the ionizing radiation ionizes air near the charged object, which then attracts whichever particles are opposite. (Electroscopes being used to detect radiation, for instance.) Specifically, I am wondering about a device patented by Tesla that is claimed to collect energy from ionizing radiation hitting a metal plate and charging it with positive charge (knocking electrons into the air?) See Talk:Solar cell#Tesla. - Omegatron 00:18, May 20, 2005 (UTC)

hi, Gamma rays are waves, not particles. This means that they have no mass and no charge. Gamma rays have a high penetrating power - it takes a thick sheet of metal such as lead, or concrete to reduce them significantly. (as stated earlier in this artice) Gamma rays do not directly ionise other atoms, although they may cause atoms to emit other particles which will then cause ionisation. ALSO We don't find pure gamma sources - gamma rays are emitted alongside alpha or beta particles. Strictly speaking, gamma emission isn't 'radioactive decay' because it doesn't change the state of the nucleus, it just carries away some energy. see below:

When Alpha or Beta particles pass another atom, they tend to pull electrons off it. We then say that the atom is "ionised".

If it has lost electrons, we call it a Positive ion.

note: Electrons have a negative charge, so losing electrons means the atom becomes positive). charge of electron: 1.60217733 (49) x 10¯19 coulombs Cheers info collected: McMillan Physics 2

The previous editor makes a few flaws. First, gamma rays are waves and particles. Gammas are so energetic that they are most often well characterized as particles. Second each gamma particle has some positive probability of interacting in any medium, so while a group of them will only be attenuated by thick shields, any one might interact anywhere. Third, gammas absolutely ionize atoms directly--how else would they generate the secondary radiation? Fourth, there are pure gamma sources, such as barium-137-m. The decay of barium-137-m is (stirctly) radioactive decay by any reasonable definition. 0¹⁸ 05:12, 1 July 2007 (UTC)

removed one exposure level

I removed the following:

15 /a -- Taiwan cobalt-60 10-year exposure, 97% lower cancer than population[1]

because the Journal_of_American_Physicians_and_Surgeons is included on quackwatch's non-recomended periodicals [2]. 0¹⁸ 19:39, 18 March 2007 (UTC)

He and CO₂

I test neutron tubes. We use He³ and CO₂ as the gases. I have notice that if i test the same tube on different days my neutron counts and my gamma rejection are not the same. My queston is, why are my results different? Does He³ and CO₂ need curing time?