Neutrons Emitted in the Disintegration of Beryllium by Deuterons

Abstract

SummaryNeutrons obtained by bombarding a thick beryllium target with 600 keY. deuterons were studied by the photographic plate technique at angles of emission of 0, 90, and 150°. Five previously reported neutron groups were confirmed giving energy lev"els of B'O at 0'73,1'75,2·20, and 3·64 MeV. An additional group corresponding to an energy level of 2·85 MeV. was observed and the evidence for regarding these as genuine beryllium neutrons is discussed. The Q-value for the ground state transition is found to be 4·35±0·02MeV. which agrees with the value 4·36±0·04 deduced from the most recent masses.

Information on Energy Levels in 8Be from Neutron Energy Spectra

“…Although a number of the observed widths are close to the proton curve, many are so high that additional neutron straggling is required to explain them. The large widths of neutron peaks has been noted by Ajzenberg (1951) and is in agreement with the high values of the straggling variance required to explain the shape of thick target neutron peaks (Dyer and Bird 1953) .…”

An accurate determination of the energy of theD(d, n)3Hereaction

“…They differ in value and accuracy (see table below) from the result of Tollestrup et al (1949) and Argo (1948) who measured the energy of the aHe recoil. The only result obtained using C2 plates, that of Dyer and Bird (1953) has an experimental error of i60 kev; this error is greater than that which can be obtained by the emulsion technique, due to the presence of the neutrons from beryllium (which were the main object of their measurement), probably low number of tracks (number not mentioned) and higher bombarding energy than the one in the present measurement.…”

XVIII.—Energy Levels of B10: Evidence from the B10 γ-ray Spectrum.

“…The only appreciable disagreement in Table II concerns the intensity of the 1-02 MeV y-ray in the spectrum gated on the 1 -02 MeV peak, and it has not proved possible to improve the agreement at this point, by simple adjustment of the intensity figures, without introducing more than one large discrepancy elsewhere. (If there were a level at about 1-25 MeV, as has been suggested by Haxel and Stuhlinger (1939), Robbins (1956) and Genin (1958), y-rays of energies 1-25 and 0-90 MeV might be associated with it; this could account for this discrepancy, for the high points in the valley at about 0-9 MeV in text- fig. 3, and for the high points in the valley at 1-25 MeV in text- fig.…”

“…EVIDENCE for a level in B 10 at 2-86 MeV was presented by Dyer and Bird (1953) after studying with nuclear emulsions the neutrons emitted in the Be 9 (d, n) B 10 reaction. Similar neutron-energy spectra have been obtained by Genin (1958), Karadeniz (unpublished work, Edinburgh 1956) and Reid (1954).…”

“…EVIDENCE for a level in B 10 at 2-86 MeV was presented by Dyer and Bird (1953) after studying with nuclear emulsions the neutrons emitted in the Be 9 (d, n) B 10 reaction. Similar neutron-energy spectra have been obtained by Genin (1958), Karadeniz (unpublished work, Edinburgh 1956) and Reid (1954). However, there was no evidence for such a level in spectra by Green, Scanlon and Willmott (1955), Pruitt, Swartz and Hanna (1953), Ajzenberg (1952), or Shpetnyi (1957).…”