Determination of the relation between the half-lives and alpha-particle energies of the emanations of urananite. The energies of alpha particles emitted by the radioactive emanations of the mineral urananite and their decay products are measured with a solid state detector. Next, radon, milked from the urananite and adsorbed on charcoal, is extracted with liquid scintillator and counted in a scintillation counter.
The rates of the various alpha particle decay processes of radon and its daughter nuclei are then measured as functions of time, and the mean lives of the various nuclei are deduced from the data according to the Bateman equations. The relation between the measured mean lives and the decay energies is compared with the theoretical relation derived according to the quantum mechanical tunneling theory of alpha decay. Finally, the range-energy relation of alpha particles is determined from a measurement of the residual energies of alpha particles as a function of the thickness of air traversed.
Lab Guide (PDF)
The solid state detector. (Image courtesy of Junior Lab staff.)
References
Gurney, R. W., and E. W. Condon. "Wave Mechanics and Radioactive Disintegration." Nature 122, no. 3073 (1928): 439.
———. "Quantum Mechanics and Radioactive Disintegration." The Physical Review 33, no. 2 (1929): 127-140.
Bleuler, Ernst, and George J. Goldsmith. "Range and Energy Loss of Alpha Particles," and "Radiations of Cu(64) (Zn(65))." Experiment 19 and 23 in Experimental Nucleonics. New York, NY: Rinehart, 1952, pp. 275-282, and 3341-354.
Sergè, Emilio. "Fundamental Principles of Particle Detection." Section 1.2 in Experimental Nuclear Physics. Vol. 1. New York, NY: Wiley, 1953, pp. 2-38.
———. "Passage of Heavy Particles through Matter." Section 2.1B-D in Experimental Nuclear Physics. Vol. 1. New York, NY: Wiley, 1953, pp. 231-252.
Perlman, I., and Frank Asaro. "Alpha Radioactivity." Annual Review of Nuclear Science 4 (1954): 157-190.
Manov, G. G. "Standardization of Radioactive Sources." Annual Review of Nuclear Science 4 (1954): 51-68.
Kohman, T. P., and N. Saito. "Radioactivity in Geology and Cosmology." Annual Review of Nuclear Science 4 (1954): 401-462.
Ritson, D. M., ed. "General Properties of Particles and Radiation." Chapter 1 in Techniques in High Energy Physics. New York, NY: Interscience Publishers, 1961, pp. 1-53.
Evans, Robley. "Beta-Ray Spectra." Chapter 17 in Atomic Nucleus. New York: McGraw-Hill, 1955, pp. 536-566.
Knoll, Glenn. "Semiconductor Diode Detectors." Chapter 11 in Radiation Detection and Measurement. 3rd ed. New York: Wiley, 2000, pp. 353-404. ISBN: 9780471073383.
Marcillac, P., N. Coron, G. Dambler, J. Leblanc, and J. Loalic. "Experimental Detection of Alpha-Particles from the Radioactive Decay of Natural Bismuth." Nature 422 (2003): 876-878.
Weinberg, Steven. The Discovery of Subatomic Particles. New York, NY: Cambridge University Press, 2003, p. 138. ISBN: 9780521823517.
Selected Resources
Table of Isotopes - Lawrence Berkeley Laboratory
Table of Nuclides - Korea Atomic Energy Research Institute