To use food irradiation, you need two things a source or radiant energy and a way to confine the energy. (1) The source for gamma radiation can either be the radioactive form of the element cobalt, which would be Cobalt 60, and the element cesium, and that would be Cesium 137. These substances do not give off neutron which means that they don’t make anything around them radioactive. When not in use, this source is kept in a pool of water which completely absorbs the radiation. To irradiate the food, the source is pulled from the pool and into a chamber with thick concrete walls. The food is then brought into the chamber and left for a certain period of time, when finished, the food is taken away and then sources is put back into the pool. (2)
The source for electron beams comes from an electron gun which shoots out a stream of high energy electrons. Since it is an electron gun, it can simply be switched on and off so no radioactivity is spread. There are some shields needed to protect the workers from the rays, but no concrete walls are needed unlike when you use gamma rays. The thing about electron radiation is that it can only penetrate about 3 centimeters, but two beams can be used to treat food that is twice that thick.
X-ray irradiation is still being developed, but it is basically a bigger more powerful version of the ones used in the hospital. The way this machine works is that a beam of electrons will be directed at a thin plate a metal such as gold, and produce a stream of X-rays that comes out from the other side. Like using the gamma ray method, X-rays can pass