Hostname: page-component-848d4c4894-75dct Total loading time: 0 Render date: 2024-05-23T18:41:32.056Z Has data issue: false hasContentIssue false

The disintegration of boron by slow neutrons. II

Published online by Cambridge University Press:  24 October 2008

C. W. Gilbert
Affiliation:
Cavendish LaboratoryCambridge

Extract

A further study has been made of the disintegration of boron by slow neutrons, B10 (n, α) Li, in the cloud chamber. The total ranges of the α-particles and the lithium particles were measured and two groups found. 91·4 % of the disintegrations form the main group, which was previously measured, and 8·6 % a long-range group corresponding to the lithium being left in the ground state. The results of the previous measurements are corrected for the variation of stopping power with velocity and the ranges in standard air of the particles of the two groups are now given as 7·7 mm. α-particle and 4·8 mm. lithium particle, total 12·5 mm. for the main group, and 9·3 mm. α-particle and 5·6 mm. lithium particle, total 14·9 mm. for the long-range group.

These results, taken together with those of other workers, make it certain that in about 92 % of disintegrations the lithium is left in an excited state of about 0·47 MeV. energy and in the remaining 8 % in the ground state. The energies calculated from this scheme by using the known masses do not agree with those deduced from the measured ranges and the range-energy relation for a-particles. It is suggested that the rangeenergy relation is at fault and that these measurements provide two experimental points to which a range-energy relation should be fitted.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1948

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

(1)Bower, , Bretscher and Gilbert. Proc. Cambridge Phil. Soc. 34 (1938), 290.CrossRefGoogle Scholar
(2)O'Ceallaigh, and Davies, . Proc. Roy. Soc. A, 167 (1938), 81.Google Scholar
(3)Goldhaber, , Hill, , Kruger, and Stallmann, . Phys. Rev. 55 (1939), 1117.Google Scholar
(4)Wilson, . Proc. Roy. Soc. A, 177 (1941), 382.Google Scholar
(5)Bøggild, . Math-Phys. Comm. Acad. Copenhagen, 23 (1945), 4.Google Scholar
(6)Livingston, and Bethe, . Rev. Modern Phys. 9 (1937), 245.Google Scholar
(7)Mattauch, and Flugge, . Kernphysikalische Tabellen (Berlin, 1942).Google Scholar
(8)Neuert, . Physik. Zeits. 36 (1935), 629.Google Scholar
(9)Good, and Hill, . Phys. Rev. 56 (1939), 288.CrossRefGoogle Scholar