damages of radiation

I Am Safe and Valuable

by Nazmiye D. (Esendeniz Teacher)
student
Kadri Şaman MTSO Vocational and Technical Anatolian High School

Introduction
There are many types of radiation, but the two most common are electromagnetic radiation and ionizing radiation. Ionizing radiation refers to radioactive particles, such as alpha and beta particles, or electromagnetic waves, such as gamma or ultraviolet rays, which have sufficient energy to detach electrons off of atoms to create ions, hence the name “ionizing radiation.” Electromagnetic radiation, which sometimes can be placed as a subcategory of ionizing radiation, deals with waves or photons from the electromagnetic spectrum. Unlike ionizing radiation, electromagnetic radiation deals with electric and magnetic field oscillations such as with X-rays, radio waves, or gamma rays.

Radioactive decay of atoms creates three radioactive particles, alpha, beta, and gamma. Of the three, alpha particles are known to have the most “ionizing power,” a term describing the number of ion pairs produced per centimeter through a material, followed by beta, then gamma. However, a common misconception is that the higher ionizing power a particle has, the more damaging it is to matter. Electromagnetic waves can also ionize, hence the reason electromagnetic radiation is often placed as part of ionizing radiation.

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Primary Electrons and Secondary Ionization
The main effect radiation has on matter is its ability to ionize atoms to become ions, a phenomenon known as ionization, which is very similar to the photoelectric effect. Radioactive particles or electromagnetic waves with sufficient energy collide with electrons on the atom to knock electrons off the atom. The electron ejected off the atom is called the primary electron. When the primary electrons hold energy, a particle ejecting the primary electron may cause it to eject another electron, either on their own atom or on another atom. This is known as secondary ionization.
However, ionization does not have to completely eject an electron off the atom. It can raise the energy of the electron instead, raising the electron energy to a higher energy state. When the electron reverts to its normal energy level, it emits energy in the form of radiation, usually in the forms of ultraviolet rays or radio waves.

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Production of X-Rays and Electromagnetic Radiation
Radiation can be both natural and synthetic. Artificially induced radioactivity utilizes primary and secondary ionizations in order to emit X-rays. Most X-ray emission is due to the bombardment of electrons on a metal target. If the electrons have sufficient energy, the inner shell electrons of the atom fall out, and higher-leveled electrons fill in the hole left by the previous electrons. By doing so, packets of energy are released in the forms of X-ray photons. Other forms of ionizing radiation can produce UV and gamma rays in a similar manner. This type of radiation is known as “ionizing radiation.”

All charged particles and rays have the ability to be radioactive; however, not all rays and particles have the energy per photon to ionize atoms. This is known as “non-ionizing radiation.” Non-ionizing radiation has enough energy to excite electrons to move to a higher state, releasing photons of electromagnetic radiation such as visible light, near ultraviolet, and microwaves. Radio waves, microwaves, and neutron radiation (an important application in fission and fusion) all fall under non-ionizing radiation, as their respective energies are too low to ionize atoms.

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Production of X-Rays and Electromagnetic Radiation
Radiation can be both natural and synthetic. Artificially induced radioactivity utilizes primary and secondary ionizations in order to emit X-rays. Most X-ray emission is due to the bombardment of electrons on a metal target. If the electrons have sufficient energy, the inner shell electrons of the atom fall out, and higher-leveled electrons fill in the hole left by the previous electrons. By doing so, packets of energy are released in the forms of X-ray photons. Other forms of ionizing radiation can produce UV and gamma rays in a similar manner. This type of radiation is known as “ionizing radiation.”

All charged particles and rays have the ability to be radioactive; however, not all rays and particles have the energy per photon to ionize atoms. This is known as “non-ionizing radiation.” Non-ionizing radiation has enough energy to excite electrons to move to a higher state, releasing photons of electromagnetic radiation such as visible light, near ultraviolet, and microwaves. Radio waves, microwaves, and neutron radiation (an important application in fission and fusion) all fall under non-ionizing radiation, as their respective energies are too low to ionize atoms.

Penetration and Radiation
Radiation, besides having the ability to ionize matter, can also penetrate through matter. How far they penetrate is dependent on the different types of radiation and their ionizing power. Since alpha particles are high in ionizing power, it is difficult for them to penetrate matter thoroughly. This is because alpha particles are likely to ionize the first thing they come into contact with; thus, they hold a small range of penetrating power. The inverse relation between ionizing power and penetrating power can be applied to beta and gamma rays as well. Alpha particles can be stopped with a sheet of paper or a layer of clothing, while beta particles can penetrate up to a fraction of an inch in solids and liquids and several feet in air. Gamma rays, which are electrically neutral and have small ionizing power, are not slowed by collisions with materials and can only be stopped with heavy metals such as lead.

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