Neutrons as Party Animals: An Analogy for Understanding Heavy-Element Fissility

Autor/in	Reed, B. Cameron
Titel	Neutrons as Party Animals: An Analogy for Understanding Heavy-Element Fissility
Quelle	In: Physics Teacher, 50 (2012) 9, S.544-545 (2 Seiten)Infoseite zur Zeitschrift PDF als Volltext Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	0031-921X
DOI	10.1119/1.4767488
Schlagwörter	Nuclear Physics; Science Instruction; Science History; Scientific Concepts; Logical Thinking + Suchen Sie Ihr Suchwort? Atomphysik; Kernphysik; Teaching of science; Science education; Natural sciences Lessons; Naturwissenschaftlicher Unterricht; History of science; Wissenschaftsgeschichte
Abstract	I teach a general education class on the history of nuclear physics and the Manhattan Project. About halfway through the course we come to the discovery of fission and Niels Bohr's insight that it is the rare isotope of uranium, U-235, which fissions under slow-neutron bombardment as opposed to the much more common U-238 isotope. As an "explanation" of the differing responses of the two isotopes to bombarding neutrons, I use the known (measured) masses of the various isotopes involved to compute the energies released upon neutron capture and then compare them to the fission barriers of the "compound" nuclei so formed (U-236 and U-239). The energy released in the (neutron + U-235) reaction exceeds the fission barrier by about one million electron-volts (1 MeV), while that for the (neutron + U-238) case falls about 1.6 MeV short. (The fission barriers are respectively about 5.7 and 6.5 MeV.) (Contains 1 table.) (As Provided).
Anmerkungen	American Association of Physics Teachers. One Physics Ellipse, College Park, MD 20740. Tel: 301-209-3300; Fax: 301-209-0845; e-mail: pubs@aapt.org; Web site: http://scitation.aip.org/tpt
Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2017/4/10