Radioisotopes, also called radioactive isotopes, are variants of chemical elements that have a different number of neutrons in the nucleus than stable isotopes of the same element. This difference makes them unstable, which means that they tend to undergo a process of radioactive decay to reach a more stable form. During decay, they emit radiation in the form of alpha, beta and/or gamma particles.
Radioisotopes are used in various fields, including:
- Medicine: For diagnosis and treatment, such as in cancer therapy or imaging studies (e.g. with technetium-99m).
- Industry: For measurements and non-destructive testing, such as checking the quality of materials or pipes.
- Scientific research: For tracing biological or chemical processes.
- Archaeology: In radiocarbon (carbon-14) dating to determine the age of ancient objects.
The distinction between sealed and unsealed radioisotope sources concerns the way in which radioactive material is contained and used. Here is an explanation:
Sealed sources:
Definition: The radioisotope is enclosed in a strong, impermeable container or capsule, which prevents any leakage of radioactive material.
Use: They are often used in industrial, medical and scientific applications where safety against leakage is required. For example, in density measuring instruments or radiotherapy.
Safety: They offer a high degree of protection against contamination because the radioactive material remains confined.
Unsealed sources:
Definition: The radioisotope is not contained in a closed capsule, so it can be handled in liquid, solid or gaseous form.
Use: Often used in nuclear medicine for diagnostic studies (e.g. in radioactive tracers) or in biological and chemical research.
Safety: They require more stringent protective measures to prevent environmental or personal contamination.
