Alpha-radiation

The limited range of a radiation can be seen in Fig. 6.2. The range depends on the energy of the a particles and amounts to several centimetres in air. Their course is practically not influenced by the collisions with electrons. Rarely an a particle collides with a nucleus and is strongly deflected, or it is captured by a nucleus and induces a nuclear reaction. 

The specific ionization of a particles in air is shown in Fig. 6.3 the number of ion pairs produced per millimetre of air increases strongly with the distance and falls off rather sharply near the end of the range of the a. particles. The increase is due to the decreasing velocity of the a. particles. As the energy decreases by about 35 eV per ion pair generated, an a particle with an initial energy of 3.5 MeV produces about 10 ion pairs. At the end of its path it forms a neutral He atom. 

The range of a particles in various substances is listed in Table 6.1. Multiplication of the range in cm by the density of the substance (g/cm ) gives the range in g/cm. Table 6.1 shows that the ranges in mg/cm are similar for very different substances they increase markedly at higher atomic numbers. 

As a measure of the absorption properties of a substance, the stopping power is used it is defined as the energy lost per unit distance travelled by the particle  

The stopping power depends on the energy of the particle, just as the specific ionization does. The range of the particles is given by 

As far as radioactive decay goes, alpha radiation is pretty slow it cam only travel a measly 10 percent the speed of light. 

Another example of a decay occurs with radium-222 when it decays to radon-218 and an emitted a particle. 

Using a nuclear equation, you can calculate that the mass number on the product side (222 for radium) equals the sum of the mass numbers on the products side (218 for radon and 4 for helium). Likewise, the atomic numbers add up. 

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Because almost all alpha radiation is stopped within the solid source and its container, giving up its energy, polonium has attracted attention for uses as a lightweight heat source for thermoelectric power in space satellites. 

The acceptance of the name was premature because both Russian and American efforts now completely rule out the possibility of any isotope of Element 102 having a half-life of 10 min in the vicinity of 8.5 MeV. Early work in 1957 on the search for this element, in Russia at the Kurchatov Institute, was marred by the assignment of 8.9 +/- 0.4 MeV alpha radiation with a half-life of 2 to 40 sec, which was too indefinite to support discovery claims. 

AinO +2 easy to reduce reduces fairly rapidly under the action of its own alpha radiation (in form of Am)... 

A Alpha radiation B Beta radiation C Gamma radiation D Delta radiation... 

Sir Ernest Rutherford (1871-1937 Nobel Prize for chemistry 1908, which as a physicist he puzzled over) was a brilliant experimentalist endowed with an equal genius of being able to interpret the results. He recognized three types of radiation (alpha, beta, and gamma). He used scattering experiments with alpha radiation, which consists of helium nuclei, to prove that the atom is almost empty. The diameter of the atomic nucleus is about 10 000 times smaller than the atom itself. Furthermore, he proved that atoms are not indivisible and that in addition to protons, there must also be neutrons present in their nucleus. With Niels Bohr he developed the core-shell model of the atom. 

M The alpha radiation from ameridum is intensive, but weak. It is particularly useful for ma-teriak testing and for measuring purposes. 

Burke, T.P. and Scott, J.A., The Production of Condensation Nuclei by Alpha Radiation, Proc. Roy. Irish Acad., 73 151-158 (1973). 

Little, J. B., A. R. Kennedy and R. B. McGandy, Lung cancer induced in hamsters by low-doses of alpha radiation from polonium-210, Science 188 737-738 (1975). 

Martell, E. A., Bronchial cancer induction by alpha radiation A new hypothesis, Paper C6-11 in Proceedings of the 7th International Congress of Radiation Research, (J. J. Broerse et al., eds), Martinus Nijhoff, Amsterdam (1983b). 

Edwards, A.A., R.J. Purrott, J.S. Prosser, and D.C. Lloyd, The Induction of Chromosome Aberrations in Human Lymphocytes by Alpha-Radiation, Internat. J. Radiation Biology 38 83-91 (1980). 

Marshall, J.H., and P.G.A. Groer, A Theory of the Induction of Bone Cancer by Alpha Radiation, Radiation Research 71 149-192 (1977). 

Radioactive plutonium isotopes emit alpha particles. The amount of radioactive plutonium in a sample can be measured by alpha spectroscopy, a technique for counting the alpha radiation. The technique is used at the Los Alamos National Laboratory (LANL) in New Mexico in order to monitor employees for exposure. 

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