Monthly Archives: January 2021

Radiation

A matter is composed of atoms. Every atom is made up of a nucleus that contains minute particles of positive charged protons and neutrons, and the negative electrons are present on the outer shell of an atom. These forces within the atom form a strong, stable balance by getting rid of additional atomic energy (radioactivity). In that process, unstable nuclei might emit some amount of energy, and this spontaneous emission is what we call radiation. In simple terms, Radiation is energy delivered by matter in the form of rays or high-speed particles.

                                                                    Protecting workers from radiation on the job - Safety Management Group, Inc.
Types of Radiation:

Radiation is categorized as Non-Ionizing and Ionizing. Non-ionizing radiation has a longer wavelength, lower frequency, and lower energy. While ionizing radiation has a short wavelength, high frequency, and high energy.

Ionizing Radiation has adequate energy to produce ions in the matter at the molecular level. It can affect the atoms in living things, so it poses a health risk by damaging tissue and DNA in genes. X-rays, Gamma rays, cosmic particles from outer space, and radioactive components are some of the examples of this kind of radiation.

Radiation Dosimeter Geiger Counter

Radiation Dosimeter Geiger Counter

This Geiger Muller Counter is used to detect X-rays, Beta, Gamma rays. These are generally called a Nuclear Radiation detector, Radiation dosimeter, Geiger counter, Radiation Scanner, etc., and are mostly used in X-Ray room or diagnostic Centre, Scrap Metal Analysis, Food, etc.

Non-Ionizing radiation is generally limited to thermal damage i.e. burns. Examples being radio waves, visible light, and microwaves. It can be used for Electromagnetic Fields, Electric fields, Radio Frequency, and Radio Spectrum Power Analyser.

EMF Meter, RF Spectrum Power Analyzer

Both types of radiations can be shown on the electromagnetic spectrum in the figure below

Physical forms of Ionizing Radiation

The energy given off by the matter is in two basic physical forms. Particulate radiation of tiny fast-moving particles that have both energy and mass (weight). This includes alpha particles, beta particles, and neutrons.

Another form of radiation is pure energy with no weight. This form of radiation is known as electromagnetic radiation and is like vibrating or pulsating rays or “waves” of electrical and magnetic energy which includes Gamma and X-rays.

In the electromagnetic spectrum, both non-ionizing and ionizing radiation beams are present. Ionizing radiation is radiation that can initiate an atom to lose or gain electrons changing its charge.

The basic classification of all the Radiation is given in the table below:

Nuclear Fission

The nucleus can split up as a result of absorbing an extra neutron called nuclear fission. Such elements are called fissile materials. One particularly notable fissile material is uranium-235– used as fuel in commercial nuclear power plants.

  • It described as the release of radiation, the release of neutrons (usually two or three), and the formation of two new nuclei (fission products).

Radioactive Decay

By emitting radiation, Large unstable atoms become more stable and get rid of excess atomic energy (radioactivity). It can be in the form of positively charged alpha particles, negatively charged beta particles, gamma rays, or x-rays. This continuing loss of radioactivity is measured in half-lives. The time taken by one-half of the atoms to decay by emitting radiation is known as the half-life. This time can range from a fraction of a second to millions of years. When radioisotopes are utilized in medicine or industry, it is crucial to know how quickly they lose their radioactivity, to know the exact amount of radioisotope that is available for the medical procedure or industrial use

Isotope Identifier

 

What Types of Radiation Are There?

The radiation from the materials includes alpha radiation, beta radiation, gamma radiation, and x radiation. Neutron radiation in nuclear power plants and high-altitude flight and emitted from some industrial radioactive sources.

  • Alpha radiation– Positively charged and is made up of two protons and two neutrons from the atom’s nucleus. They are heavy and very short-range particles and are actually ejected helium nucleus. Alpha radiation has high ionization but low penetrating power. Rubber gloves, flu masks, even paper sheets on the human body can be protected from alpha radiation. However, penetrating the human body via air, water, or food, can be hazardous. Examples of alpha emitters include radium, radon, uranium, thorium.
  • Beta radiation – Light, short-range particle and is actually an ejected electron. They have higher penetrating power than alpha. Any shelter may help in protection from Beta particles. They can easily pierce human skin and cause tissue damage and burns. Most beta emitters can be identified with a survey instrument and a thin-window GM probe. Some beta emitters, however, have very low-energy, poorly penetrating radiation and may be impossible to detect.
  • X-rays and Gamma radiation– Gamma radiation and x rays are highly penetrating electromagnetic radiation. Gamma rays are photons that emanate from the nucleus of the atom. It is extremely difficult to protect ourselves from X-rays and gamma-rays. The intensity may be reduced up to two times with steel (2,8 сm thick), concrete (10 сm), soil (14 сm), wood (30 сm).
  • Neutron radiation denotes the flow of neutrons, i.e. high-speed nuclear particles that have an excellent ability to penetrate other materials and can travel great distances in air and require very thick hydrogen-containing materials to block them. One may use a protective shelter, radiation protective covers, specially equipped basement or cellar for protecting from this radiation. Fortuitously, however, neutron radiation mainly occurs inside a nuclear reactor, where many feet of water provide effective shielding.

Units of radiation:

Common Radiation Sources:

 

 

Detecting Radiation

  • Since radiation cannot be seen, heard, smelled, tasted, or felt they require certain devices to detect. Radiation exists in different physical states, including liquids and gases.

Personal Radiation Detector (PRD)

A PRD is a vesture gamma and/or neutron radiation detector, nearly the size of a pager. When exposed to radiation levels, the device alarms with flashing lights, tones, and/or vibrations. Most PRDs have a numerical display the detects radiation intensity (on a scale of 0 to 9) and, can also be used to locate a radiation source; however, they typically are not as sensitive as hand-held survey meters and cannot identify the kind of radioactive resource.

Handheld Survey Meter

The survey meter is a hand-held radiation detector, which usually measures the amount of radiation present and provides this information on a numerical presence in parts of counts per minute and second, or micro roentgen (µR) or microrem (µrem) per hour. Mostly these devices detect beta and gamma radiation. some types can detect alpha, beta, gamma, and/or neutron radioactivity produced from radioactive materials.

Geiger counter is one particular meter, specifically designed to detect gamma and x-ray radiation. It can be extended to about 4 meters to measure very high dose rates without exposing the user. In addition, these devices normally have the ability to measure dose rates varying from 0 to 1,000 rad per hour.

Radiation Isotope Identification Device (RIID)

It is a radiation detector with the capacity to analyze the energy spectrum of radiation, in order to identify the particular radioactive material (radionuclide) that is emanating the radiation. In addition, these gadgets can be used as survey instruments to detect radioactive materials.

Radiation Portal Monitor (RPM)

An RPM is a large pass-through radiation screen for personnel, vehicles, container boxes, or trains. Typically, these devices consist of two columns containing radiation detectors, which are remotely monitored from a display panel. The monitor alarm indicates the presence of radioactive materials, including low-radiation materials like uranium.

Terms used in Radiation:

  • Radioactivity — the amount of radiation discharged by a material. Whether it emits an alpha particle or beta particles, gamma rays, x-rays, or neutrons—expressed in terms of its radioactivity (or simply its activity), —how many atoms in the material decay in a given time period. —curie (Ci) and becquerel (Bq).
  • Exposure: The amount of radiation traveling through the air. radiation monitors measure exposure—roentgen (R) and coulomb/kilogram (C/kg).
  • Absorbed dose: The amount of radiation absorbed by an object or person—radiation absorbed dose (rad) and gray (Gy).
  • Dose equivalent (or effective dose): Radiation absorbed and the medical effects of that type of radiation. beta and gamma radiation, the dose equivalent is the same as the absorbed dose— a roentgen equivalent man (rem) and Sievert (Sv), and biological dose equivalents are commonly measured in 1/1000th of rem (known as a millirem or mrem).