LIV. Nuclear reactions produced by slow negativeπ-mesons
- 1 June 1950
- journal article
- research article
- Published by Taylor & Francis in Journal of Computers in Education
- Vol. 41 (317), 583-618
- https://doi.org/10.1080/14786445008561123
Abstract
Reactions produced by the nuclear capture of slow negative π-mesons have been studied by the photographic method. The disintegrations of the light and heavy elements of the emulsion have been distinguished by methods which are described in detail. Because of the large number of “stars” observed—more than 2500—it has been possible to make a statistical approach to the study of the disintegrations. The general features of the “stars” produced by the disintegration of heavy nuclei are in satisfactory agreement with the predictions of the evaporation theory. In addition, the emission of fast, singly-charged particles has been observed, most of which must be attributed to an alternative process to that of evaporation. Preliminary results have been obtained for the frequency of emission and the energy “spectrum” of these particles. The conclusion is reached that in the initial process of capture—the so-called “primary” process—the energy corresponding to the rest-mass of the φ− meson is shared among a larger number of nucleons than has commonly been assumed hitherto. Observations on “stars” produced by the disintegration of light nuclei indicate that there is a wide variety in the characteristics of the disintegrations which appear to be strongly dependent on the manner in which the primary distribution of energy takes place. A detailed analysis has been made of some of the disintegrations due to 12 6C and 14 7N nuclei, by applying the conservation laws of mass energy and momentum. In the majority of cases, the primary interaction results in the production of one or two fast neutrons and an excited residual nucleus which then disintegrates. In a few eases, however, the primary interaction involves the nucleus as a whole, resulting in its total disruption and the ejection of fast α-partieles.Keywords
This publication has 17 references indexed in Scilit:
- XV. Nuclear transmutations produced by cosmic-ray particles of great energyJournal of Computers in Education, 1950
- Observation of ( , T), ( , D) and ( , np) Reactions in BoronProceedings of the Physical Society. Section A, 1950
- VII. On the mass of charged particles of the cosmic radiationJournal of Computers in Education, 1950
- Nuclear Disintegration by -Meson CaptureProgress of Theoretical Physics, 1949
- On the Nuclear StarsProgress of Theoretical Physics, 1949
- The Decay and Capture of -Mesons in Photographic EmulsionsProceedings of the Physical Society. Section A, 1949
- XLVII. Origin of cosmic ray starsJournal of Computers in Education, 1949
- Charged Particles Emitted by Carbon Bombarded by 90 Mev NeutronsPhysical Review B, 1949
- The Interaction of High Energy Neutrons and Heavy NucleiPhysical Review B, 1948
- The Capture of Negative Mesotrons in MatterPhysical Review B, 1947