Beta emission structures

There are five main types of emissions alpha emission, beta emission, positron emission, electron capture, and gamma emission. Four of these produce changes in the elements undergoing decay, and the end result is a more stable atomic structure. 

Four main Cu sites, reflected in the Cu emission bands and corresponding IR bands of NO adsorbed on Cu have been found, common to high silica MFI, mordenite, erionite and beta matrices. It has been shown that the Cu coordination is controlled by the (-Al-0-(Si-0) -Al-) local sequences and not by the structural type (symmetry of the oxygen rings) and the overall Si/Al ratio. However, as the distribution of the Cu sites reflects the distribution of the A1 siting in zeolites, it implies various population of the individual Cu sites in zeolites of various structure and Si/Al ratio. 

About ten different isotopes of iodine have been used medically. is the most frequently used isotope for diagnostic studies of thyroid function and structure (Williams, 1986). This isotope has a short half life (13.3 h) and emits X-rays, gamma-photons, but no beta particles. In comparison, has a half life of about 6-8 days and emits beta particles and gamma rays. The beta particles result in local thyroid damage gamma emissions facilitate external diagnostic imaging. 

Further evidence of the complex structure of the atom was provided in 1896 by the discovery, by the French physicist Becquerel, of the phenomenon of radioactivity. It was found that certain elements, such as uranium, spontaneously emitted radiation at an apparently constant rate. Ernest Rutherford showed that the emissions involved two types of particle, to which he gave the names alpha (a) and beta (jS) rays. The first of these had a positive charge and a mass essentially equal to that of an atom of the element helium, while the second was found to be simply an electron. In 1903, Rutherford, in collaboration with Frederick Soddy, explained the process of radioactivity by the revolutionary hypothesis that the particle emission was a means whereby an atom of one element converted itself spontaneously into an atom of another. 

The discovery of radioactivity—the emission of small energetic particles from the core of certain unstable atoms— by scientists Henri Becquerel (1852-1908) and Marie Curie (1867-1934) at the end of the nineteenth century allowed researchers to experimentally probe the structure of the atom. At the time, scientists had identified three different types of radioactivity alpha (a) particles, beta (/3) particles, and gamma (y) rays. We will discuss these and other types of radioactivity in more detail in Chapter 19. For now, just know that a particles are positively charged and that they are by far the most massive of the three. 

The La isotope is present in the natural lanthanum with an abundance of 0.09% and its lifetime is of the order of 1011 years. The contribution of La dec in the energy spectra of Figure 8 consists in i) the multi peak structure located at approximately at 1460 keV (from EC La -> Ba), the structure between 750-1000 keV generated by the sum of the 789 keV gamma with the coincident electron of the beta decay La -> Ce) and iii) the low energy continuum structure. The contamination due to the produces the P continuum up to approximately 1400 keV due to the beta decay of "Pb and ° T1 in the decay chain of this nucleus. There are also events due to a emission from Th, Ra, Rn, Po, and "Bi populated by the Ac alpha-decay chain. 

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