The Fermi Chronicles - Part 3: Radiation Types

Radiation is simply the result of unstable atoms. Unstable atoms want to become stable (don't we all?) and do this by emitting radiation of various types. There are 4 major types of radiation that could be harmful and that are the focus at Fermi 2 - alpha, beta, gamma and neutron radiation.

Alpha radiation - this is the weakest of the 4 (there's more than just 4 in totality, but anyway). It is a real particle and is thus a type of radiation referred to as particle radiation. It is basically the nucleus of a helium atom (2 protons, 2 neutrons) but without the electrons. Usually, atoms have a balance between positive protons and negative electrons. A helium nucleus without electrons has a net positive charge, and it is called ionized. Because alpha particles are large, they are easily blocked by even a sheet of paper. The danger is if the particles are inhaled or ingested somehow. As it turns out, the DNA molecule has a slight negative charge, which will attract the positively charged alpha particle. Chaos ensues. Not good.

Beta radiation - this is also a form of particle radiation. Whereas alpha radiation is a clump of 2 protons and 2 neutrons, beta particles are loose electrons (or positrons), but unlike regular electrons they are discharged from the nuclear core, not from atomic orbit. Because of their much smaller size, beta particles travel much greater distances and are also much faster. Beta particles, just like alpha particles, are ionized (whereas the alpha particles carry a positive charge, beta radiation carries a negative charge. Except for positron emissions (positive electrons) that are positive, but I'll skip that for now). Beta particle have greater penetrating depth than alpha particles, but still cannot penetrate material such as plexiglass.

Gamma radiation - this stuff is worse than alpha or beta radiation because it is pure energy, and does not involve a particle with rest mass (but does involve a photon (not the Star Trek photon) since all electromagnetic radiation travels as both a particle and a wave). Thus, it has a far greater penetrating depth, like x-rays but even more powerful. It will go right through you damaging atomic structures as it passes through. Gamma rays can be shielded by thick lead barriers, but it's nothing that you will be wearing.

Neutron radiation - this type of radiation is emitted by nuclear fission of material such as uranium and is necessary for self-sustaining the fission chain reaction. Because neutrons don't have a charge, they are the most penetrating of the particles. Neutron radiation by itself would appear less harmful, but the problem is its interaction with matter. That neutron will eventually merge with the nucleus of an atom, for example, an atom inside your body, making it unstable. The unstable atoms then have a tendency to emit alpha, beta and gamma radiation to become stable again and things just go downhill from there.

Neutron radiation is a necessary byproduct of fission, while alpha, beta and gamma radiation are emitted by radioactive decay (and fission). In the next installment, I will talk more broadly about the different forms of electromagnetic radiation. People tend to freak out when they hear the word 'radiation,' but visible light is an example of a type of electromagnetic radiation, so is radio, and the old UHF and VHF tv frequencies, etc. So it's not all bad.Previously:
The Fermi Chronicles - Part 2: A week of training
The Fermi Chronicles - Part 1: The alpha post