Radiation beta particles

Beta particle Radiation in the form of an energetic electron emitted from the nucleus of an atom. Negatively charged (-1) radiation particle consisting of an energetic electron emitted from the nucleus of an atom. 

Almost all radioactive nuclides that emit alpha particles are in the upper end of the periodic table, with atomic numbers greater than 82 (lead), but a few alpha-particle emitting nuclides are scattered through lower atomic numbers. The reason why alpha-particle emitters are limited to nuclides with larger mass numbers is that generally only in this region is alpha-particle emission energetically possible. Most radioactive nuclides with smaller mass numbers emit beta-particle radiation. 

On the other hand, the low concentration of a radionuclide provides opportunities for use as tracer in chemical and physical studies. In radioanalytical chemistry, one benefit is that the addition of a stable-element carrier permits analysis without the requirement of quantitative analyte recovery. Another benefit is the opportunity to deposit very thin sources that minimize self-absorption in a source of alpha-and beta-particle radiation. 

X-rays, gamma rays, or beta particle radiation... 

The 140 KeV photons emitted by Tc are accompanied by few conversion and Auger electrons and no beta-particles which increase the radiation dose without adding to the imaged information, and no gamma- or x-rays of other energies. These other gamma- or x-rays, if substantially lower in energy. 

Gamma ray The shortest wavelength and highest energy type of all electromagnetic radiation. It originates in the nucleus of radioactive isotopes along with alpha particle, beta particle, or neutron emissions. 

Neutron activation reactions have also been considered for mine detection. Here a radioactive element is produced in the mine which in the process of decay, emits nuclear radiation, either alpha or beta particles or yrays or two of these or all three in combination. For buried mines the penetrating 7iays are of most in-... 

The nuclear reactor also must be shielded against the emission of radioactive material to the external environment. Suitable radiation controls include both thermal and biological shielding systems. Radiation from alpha particles (a rays) and beta particles ((3 rays) has little penetrating power, but gamma rays have deep penetration properties. Neutron radiation is, however, the primary area of risk. Typically, extremely thick concrete walls are used as a neutron absorber, but lead-lined concrete and special concretes are also used. 

Because exposure to radiation is a health risk, the administration of radioactive isotopes must be monitored and controlled carefully. Isotopes that emit alpha or beta particles are not used for Imaging, because these radiations cause substantial tissue damage. Specificity for a target organ is essential so that the amount of radioactive material can be kept as low as possible. In addition, an Isotope for medical Imaging must have a decay rate that is slow enough to allow time to make and administer the tracer compound, yet fast enough rid the body of radioactivity in as short a time as possible. 

The numerical combination of protons and neutrons in most nuclides is such that the nucleus is quantum mechanically stable and the atom is said to be stable, i.e., not radioactive however, if there are too few or too many neutrons, the nucleus is unstable and the atom is said to be radioactive. Unstable nuclides undergo radioactive transformation, a process in which a neutron or proton converts into the other and a beta particle is emitted, or else an alpha particle is emitted. Each type of decay is typically accompanied by the emission of gamma rays. These unstable atoms are called radionuclides their emissions are called ionizing radiation and the whole property is called radioactivity. Transformation or decay results in the formation of new nuclides some of which may themselves be radionuclides, while others are stable nuclides. This series of transformations is called the decay chain of the radionuclide. The first radionuclide in the chain is called the parent the subsequent products of the transformation are called progeny, daughters, or decay products. 

Beta radiation is a stream of negatively charged particles, known as beta particles, which have the same mass and electric charge as the electrons. Beta radiation travels in the air longer distances than alpha... 

Gamma radiation has a very high penetrating power. A small fraction of the original stream will pass through several feet of concrete or several meters of air. The specific ionization of a gamma is low compared to that of an alpha particle, but is higher than that of a beta particle. 

Gas-filled detectors are used, for the most part, to measure alpha and beta particles, neutrons, and gamma rays. The detectors operate in the ionization, proportional, and G-M regions with an arrangement most sensitive to the type of radiation being measured. Neutron detectors utilize ionization chambers or proportional counters of appropriate design. Compensated ion chambers, BF3 counters, fission counters, and proton recoil counters are examples of neutron detectors. 

Whereas Table 2 presents some radiation terms that are pertinent to the following discussion, Table 3 lists the radioisotopes and their half-lives that are suitable to microautoradiography. Of the two types of nuclear radiation, i.e., wavelike electromagnetic radiation (X-ray and gamma ray) and corpuscular radiation (electrons, beta particles, and alpha particles) the latter are the most employable for microautoradiography. The reader is referred to Slater (20) for in-depth discussion of all aspects of radiobiology. 

Radiation (ionizing) Alpha particles, beta particles, gamma rays, x-rays, and other particles capable of producing ions does not include nonionizing radiation forms such as radio waves, microwaves, or visible, infrared, or ultraviolet light. 

The sample is placed on a photographic film which is protected from the light and allowed to remain in contact long enough for an adequate exposure. The exposure time is dependent upon the intensity of the radiation and can usually only be determined by trial and error. It is possible, however, to predict an approximate exposure time from the fact that a total emission of 107 beta particles per square centimetre is often required. 

In the last four years of the nineteenth century, scientists in France— notably Henri Becquerel and Marie and Pierre Curie—discovered that certain elements are radioactive. That is, their atoms naturally emit positively charged particles (alpha particles), negatively charged particles (beta particles), and energy (gamma radiation). 

---