Gamma ray

1. * Ultrasound techniques are used to detect structure inside the body. A gel is used when a 1MHz transducer is placed on the skin to avoid acoustic mismatch at the skin-transducer interface. (a) Define acoustic mismatch (in this particular case). Acoustic mismatch, by definition, is the discrepancy between the acoustic impedances of two or more mediums (MacLennan, 2006). This occurs when a propagated soundwave, passing through one medium, travels into another medium of unequal impedance. In the

are made naturally and some are made unnaturally. Radioactive Cobalt-60 is not naturally made. It is formed when cobalt-59 is collided by a neutron making it the radioactive isotope (3). Cobalt decays to form Nickel-60. As it decomposes, it releases gamma radiation. Beta particles also occur when Carbon-60 decays (4). The nuclear

to refer to the amount of radioactive materials released into the environment. 2.2.2) Radiation exposure unit: The exposure rate defined as the exposure per unit time. The special unit of exposure is the roentgen (R) defined as the amount of gamma ray and X- ray radiation that produced a charge of 1 electrostatic unit (esu) of charge per 0.001293 g (1cm3) of dry air at standard temperature and pressure (IAEA, 1989). The SI (stander international) units of exposure are coulomb/Kg of dry air.

liver, thyroid and bone cancer. Uses: 1. Technetium -99m is used to image the skeleton, heart muscles, brain, thyroid, lungs, and bone marrow. Technitium-99, is used as radioactive tracer which can be detected in the body by gamma cameras. Computers process the image when the gamma camera is rotated around the patient. It takes 15-20 seconds for each projection which are collected every three to six degrees and takes a total of 15-20 min for a total scan (Uses of Technetium-99m). 2. Myocardial perfusion

A heterogeneous beam of X-rays is produced by an X-ray generator and then it is projected toward the object. A certain amount of X-ray is absorbed by the object, which depends on the particular density and composition the object has. The X-rays that pass through the object, are captured behind the object by a detector. This detector can capture a 2D representation of all the object's

& Prof. Francis Livens 1. Introduction Nuclear conversion of an atomic nucleus from one form to another is known as radioactivity. These conversions are accompanied by nuclear radiations, major nuclear radiations are alpha, beta and gamma radiations these are ionisations radiations and hence are dangerous to living beings these radiations can cause radiation sickness and sometimes can even lead to death. However these nuclear radiations can be detected and measured and considerable

Introduction: Humankind in the modern world is strife with daily battles ranging from treating cancerous tumours to finding out if oil is flowing in a trans-siberian oil pipeline. Radioisotopes seem to hold a solution to these and many more serious and challenging issues. Global Issue: Being able to survive is the key to the existence of the Human race. In our endeavour to survive, we now need to tackle Cancer; the untamed monster of the modern era. Radioisotopes can be crucial to this survival.

sources consists of food irradiation, which is limited to high-energy gamma rays, X-rays and accelerated electrons. Ionizing is source of radiation because of the high-energy free electrons from atoms and molecules. The electrically charged particles are converted to ions. Microwaves are example of gamma rays. Accelerated electrons can transfuse to treat the food only to a depth of three centimeters. Due to thickness of x-rays may pass through the food. Radiation dose is the quantity of radiation

Causative Agent: A total body exposure of one hundred roentgens of radiation will cause radiation sickness. Although certain medical devices will give you exposure to radiation, the grays of radiation are miniscule and will not cause radiation sickness. There are a few sources that can lead to a high enough exposure of roentgens of radiation. One of these sources involves accidents or attacks involving nuclear facilities. The other has to do with accidents or being the target of radioactive or

detection and monitoring operation. Ionizing radiation such as x-ray, gamma, alpha, beta and neutron radiations, are not only harmful to human health(Azzam et al. 2012) and environment(Mothersill&Seymour 2014), but also can damage the electronic devices(Wang et al. 2014). The source of these ionizing radiations are from radioactive materials, x-ray tubes, particle accelerators such as ion beams, nuclear weapons and reactors, cosmic rays from space and from natural rocks and minerals. Exposure of extremely