النشاط الاشعاعي الاصطناعي - الطاقة النووية .. الفيزياء

Artificial Radioactivity - Nuclear Energy .. Physics

Artificial Radioactivity

Radioactive isotopes are produced artificially by bombarding some atoms with very fast neutrons.

We can also produce them by exposing a natural element to neutron rays inside a nuclear reactor, which captures its nucleus. This method is used to prepare cobalt-60 (27 protons and 33 neutrons) from cobalt-59 (27 protons and 32 neutrons).

All of these isotopes become unstable due to the presence of additional neutrons in them, and thus become radioactive.

Radioactive isotopes have many uses, some of which are related to diagnosing and treating diseases such as cancer. The radioactive isotope has the same chemical properties as the stable isotope of the same element, and therefore follows the same path inside the human body. It is known that some elements accumulate in certain parts of the body or in some of its organs. If some of the cells in it become overactive, such as cancer cells, this leads to an increase in the accumulation of the appropriate element.

The task of the radioactive isotope is to determine the location of the tumor in the body due to its high density, which causes a greater number of decays compared to the decays caused by healthy cells. For example, the radioactive isotopes 131Y and 125Y, which accumulate in the thyroid gland like natural iodine (and also in the kidneys) and indicate excessive or lazy activity in these organs. It is very important that the half-lives of the isotopes used in medicine be relatively short so that they can decay quickly, and that the rays emitted from them have sufficient energy to be captured by an external counter. It is worth noting that the rays emitted from highly concentrated isotopes are capable of killing cancer cells, and they are used either outside the body - such as skin cancer - or inside it.

We can introduce tritium 3H, a radioactive isotope, into a chemical substance (it then becomes a radioactive substance), study its path inside the body, and concentrate it in a medium that cannot be normally affected. In this way, the formation of organic chemicals and their reactions inside the body are studied.

(Scanning shows the concentrations of radioactive isotopes that are absorbed by an overactive tissue.)

(A radioactivity source can be used to check the thickness of a continuously produced metal plate.)