"Ionising radiation is any EM wave or particle that carries sufficient energy to ionise (remove electrons) from an atom.
There are two types of EMR that are ionising – x-rays and gamma rays. There are three types of nuclear particle that are ionising – alpha particles, beta particles and neutrons.
When ionising radiation interacts with matter, it creates secondary radiation of a lower energy. Together, the primary and secondary radiation then trigger ionisation in the environment and the synthesis of highly reactive free radicals! Moreover, energy is released as heat. The linear energy transfer (LET) describes the loss in energy of primary radiation. It is a numerical expression of the particle energy lost to the medium per unit track length. Unit is Jm-1.
LET value high for: a radiation, fast nuclear fragments (during nuclear fission), low for: photon radiation.+"
Erm, I think a good example of this would be a nuclear reactor. You've got the primary radiation coming from the fuel rods, they're emitting neutrons. Those neutrons then interact with atomic nuclei within the reactor, causing them to become unstable and radioactive. The radiation from those "affected" atoms is the secondary radiation, because it is caused by the primary radiation interacting with them.
Ah right, I see! So, the primary radiation is being emitted from the fuel rods and the primary radiation in your example are the neutrons. So it's sorta like this in a different situation, right?