physics : 7.14, 7.15, 7.16

what is contamination

contamination occurs if an object has a radioactive source introduced into it.

what is irradiation

exposing objects to radiation outside of the object, it stops as soon as the source is removed

alpha particle use

alpha particle are used in smoke detectors as they will ionized the air within detector, creating a current. However the alpha emitter is blocked when smoke enters so alarm triggered when ammeter no longer detects current. Alpha is used as it is the most weakly penetrating so the least dangerous when contained and also the most ionising so it is best at creating a current

beta particles use

measuring the thickness of materials. The volume of beta particles which can penetrate the material increases as the thickness decreases. Beta is used as alpha particles have too little penetrating power and gamma has too much.

radioactive use - pipe leaks

industrial tracers which detect leaks in underground pipes, by placing a radioactive isotope within the pipe and using a Geiger muller detector find the point with the highest count rate

uses of radiation - food

used for sterilization and preservation of food even after packaged. typically using cobalt 60 gamma rays as they will destroy bacteria and is most penetrating.

uses of radiation in medicine

radiotherapy : gamma rays can kill the cancer cells,
tracers are radioactive isotopes which track the movement of substances like blood around the body, a PET scan can detect the emissions from the tracer to find clots/tumor/cancer, sterilize equipment. Gamma rays used as alpha and beta too ionising and would harm body

difference between contamination and irradiation

in irradiation the object is exposed to radiation but does not become radioactive, in contamination the object becomes radioactive. irradiation occurs when radiation is emitted from a source outside the object, in contamination the radiation emitted from within the object

dangers of ionising radiations

as they are ionising they can cause mutations in living organisms, they can damage cells and tissue

how to mitigate risk of radiation exposure

radioactive sources kept in a shielded lead container when not in use. materials only handled wearing gloves and tongs. wearing protective clothing, limiting time with radioactive source