Ionizing radiation
Introduction
Ionizing radiation refers to energy or particles that, when interacting with atoms, have enough energy to remove tightly bound electrons from their orbits, causing the atom to become charged or ionized. This form of radiation is categorized into two types: direct and indirect ionizing. Direct ionizing radiation includes alpha particles, beta particles, and charged nucleons, while indirect ionizing radiation includes gamma rays, x-rays, and neutrons.
Types of Ionizing Radiation
Ionizing radiation can be categorized into two types: direct and indirect ionizing radiation.
Direct Ionizing Radiation
Direct ionizing radiation has enough energy to ionize atoms directly by fundamental particle interaction. This type of radiation includes alpha particles, beta particles, and charged nucleons.
Alpha Particles
Alpha particles consist of two protons and two neutrons bound together into a particle identical to a helium nucleus. They are generally produced in the process of alpha decay, but may also be produced in other ways. Alpha particles are named after the first letter in the Greek alphabet, α.
Beta Particles
Beta particles are high-energy, high-speed electrons or positrons emitted by certain types of radioactive nuclei such as potassium-40. The production of beta particles is termed beta decay. They are designated by the Greek letter β.
Charged Nucleons
Charged nucleons are particles found in the nucleus of an atom. The two types of nucleons are protons and neutrons. Protons are positively charged, while neutrons have no charge.
Indirect Ionizing Radiation
Indirect ionizing radiation is radiation that does not carry enough energy to ionize atoms or molecules on its own, but can lead to ionization if the particles interact with the atomic electrons. This category includes gamma rays, x-rays, and neutrons.
Gamma Rays
Gamma rays are a form of electromagnetic radiation, similar to x-rays. They are produced by sub-atomic particle interactions such as electron-positron annihilation, neutral pion decay, fusion, and radioactive decay.
X-Rays
X-rays are a type of radiation called electromagnetic waves. X-ray technology is widely used in applications such as medical imaging and crystallography.
Neutrons
Neutrons are particles that carry no charge, and they are found in the nucleus of an atom. They can cause ionization indirectly when they collide with atomic nuclei.
Effects of Ionizing Radiation
Ionizing radiation can have significant effects on living organisms and materials. These effects can be categorized into deterministic effects, stochastic effects, and genetic effects.
Deterministic Effects
Deterministic effects of ionizing radiation occur above a certain threshold of radiation dose. The severity of the effects increases with the dose. Examples include radiation sickness, skin burns, and cataracts.
Stochastic Effects
Stochastic effects of ionizing radiation occur by chance and the probability of occurrence increases with the dose. There is no threshold below which the effect cannot occur. Examples include cancer and genetic mutations.
Genetic Effects
Genetic effects of ionizing radiation are those that can affect the offspring of the person exposed to the radiation. These effects can include increased risk of genetic diseases and malformations.
Protection from Ionizing Radiation
Protection from ionizing radiation is necessary to minimize the harmful effects of exposure. This can be achieved through time, distance, and shielding.
Time
Reducing the time of exposure to ionizing radiation can significantly decrease the dose received.
Distance
Increasing the distance from the source of ionizing radiation can also reduce the dose received, as the intensity of radiation decreases with distance.
Shielding
Using shielding materials can absorb or block the ionizing radiation, reducing the dose received. The type of shielding material used depends on the type of radiation.