| 释义 |
spallation|spəˈleɪʃən|
[f. spall v.1 + -ation.]
1. Nuclear Physics. The detachment of a number of nucleons or small nuclei from a larger nucleus, esp. as a result of the impact of an energetic nucleon or other particle. Freq. attrib., as spallation product.
1948Lapp & Andrews Nuclear Radiation Physics xiii. 305 When a high-energy neutron strikes a target nucleus, a reaction known as spallation may occur. 1950Glasstone Sourcebk. Atomic Energy x. 259/2 They do not undergo fission and break up into two, more or less equal, parts. Instead, such nuclei emit various numbers..of nucleons, leaving a series of products of lower mass and atomic number. The name spallation has been proposed for reactions of this kind. [Note] This term is based on the verb ‘to spall’, meaning to break up by chipping off small fragments, which was suggested as appropriate by W. H. Sullivan. 1953Ann. Rev. Nuclear Sci. II. 401 O'Connor & Seaborg..bombarded uranium with 380-Mev α-particles and then analyzed radiochemically for spallation and fission products. 1962B. G. Harvey Introd. Nuclear Physics & Chem. ix. 183 Reactions in which several particles are emitted are often called ‘spallation’, regardless of the mechanism by which they take place. 1979Nature 15 Feb. 519/1, 18C can be produced fairly readily in heavy ion collisions, or as a spallation product of heavy nuclei.
2. gen. Spalling.
1971New Scientist 8 Apr. 72/3 An outer spallation zone due to the interaction of shock waves with the rock surface. 1974Hawkey & Bingham Wild Card xv. 133 The crash guys..look for recrystallization at micropromontories, Neumann banding, parallel banding, spallation. |