Radiation Protection - Theoretical Lec3 PDF

Radiation protection – Theoretical Lec3. Asst.Lec.Nibras Hayder Hmood Particulate radiation  Particulate radiation is the radiation of energy by means of fast-moving subatomic particles that has finite mass and may or may not carry a charge.  Particulate radiation is primarily prod...

Radiation protection – Theoretical Lec3. Asst.Lec.Nibras Hayder Hmood Particulate radiation  Particulate radiation is the radiation of energy by means of fast-moving subatomic particles that has finite mass and may or may not carry a charge.  Particulate radiation is primarily produced by disintegration of an unstable atom.  Particulate radiation is of four forms:  Positively Charged alpha particle ().  Positively charged (Positrons) or negatively charged (Electron) beta particles (β + or β -).  neutrons, subatomic particles which have no charge.  photons (called a gamma ray γ, and x-ray) ALPHA PARTICLE  Alpha Particles: The alpha particle emitted from the nucleus of some radionuclides during a form of radioactive decay, called alpha-decay, giving off a particle (called an alpha particle).  consisting of two protons and two neutrons (essentially the nucleus of a helium atom ,changing the originating atom to one of an element with an atomic number 2 less (Z-2) and atomic weight 4 less (A-4) than it started with. Beta Particles  The emission of a beta particle from the nucleus of an atom.  Beta radiation takes the form of either an electron () or a positron () (a particle with the size and mass of an electron, but with a positive charge) being emitted from an atom.  Beta particles are high energy, high speed electrons or positrons that are ejected from the nucleus by some radionuclides during a form of radioactive decay called beta-decay.  The penetrating power of β rays is greater than that of -rays; but can be stopped by thin aluminum. It can penetrate skin a few centimeters, posing somewhat of an external radiation hazard. Neutron  It consists of a free neutron.  Usually emitted as a result of spontaneous or induced nuclear fission.  Able to travel hundreds or even thousands of meters in air, they are however able to be effectively stopped if blocked by a hydrogen-rich material, such as concrete or water.  Not typically able to ionize an atom directly due to their lack of a charge, neutrons most commonly are indirectly ionizing (secondary radiation hazard ),  Neutrons are, in fact, the only type of radiation that is able to turn other materials radioactive. Gamma rays  Gamma rays are a type of electromagnetic radiation with the highest frequency and shortest wavelength in the electromagnetic spectrum.  Gamma rays are typically emitted during nuclear reactions, such as those occurring in stars, nuclear power plants, and nuclear explosions. They can also be emitted by certain radioactive materials, such as uranium and plutonium.  Gamma rays are highly ionizing, meaning they can remove tightly bound electrons from atoms, leading to the creation of charged particles (ions). This characteristic can be hazardous to living organisms as it can cause cellular damage and DNA mutations.  These rays are highly energetic and penetrating Power, it have excellent penetrating power and can easily pass through materials such as paper, skin, and even dense metals. This property makes them useful in various applications, including medical imaging and industrial inspections.  Has very low penetration power and can be stopped by a thin sheet of paper. Alpha particles are unable to penetrate the outer layer of dead skin cells. The risks of radiological examination  The risks of radiological examination. Radiography examination involves exposing the patient to ionizing radiation in order to create images of the internal structures of the body. The risk from radiation examinations depends on several factors, including the type of exam, the number of exams performed, the age and sex of the patient, and the part of the body being examined. The risk is generally considered to be higher for children, pregnant women, and individuals who have had many previous radiation exams. While radiography is generally considered safe, there are some risks associated with the procedure. Thank You