Deuterium Bombardment Research Articles

The Production of Mesons by Protons on Deuterons

An attempt is made to predict the energy and angular distribution of charged mesons to be expected from the bombardment of deuterium by 345-Mev protons assuming that the cross section for production in two-nucleon collisions is known. The problem is simplified by assuming that the third particle enters the reaction only by giving to the struck particle a momentum distribution at some time prior to the meson production, by carrying off the complementary momentum, and by limiting the states available through the exclusion principle. The possibility of the reformation of a deuteron more than doubles the cross section for the production of positive if it occurs. Hence the positive-negative ratio offers an experimental means of determining the spin dependence of positive meson production in the final state, assuming that the ratio of $p\ensuremath{-}n$ to $p\ensuremath{-}p$ production is known. Alternatively, this approach offers a method for a rough determination of the $p\ensuremath{-}n$ meson production cross section using high energy proton beams.

Applications of photographic method to problems in nuclear physics. I (a) The determination of the energy of homogeneous groups of α-particles and protons (b) The determination of the energy of fast neutrons

A detailed account is given of an application of the photographic method to the determination of the energy of homogeneous groups of particles from nuclear reactions. The particles studied are (a) α-particles from thorium and uranium; (b) protons from the disintegration of boron and lithium by 500 ekV deuterons, and (c) neutrons from the deuteron bombardment of deuterium, beryllium, boron and fluorine. It is shown that the experimental width at half maximum of a homogeneous group of particles is nearly independent of the energy in the range from 1 to 13 eMV, and is equal to 0·3 eMV for protons and 0·5 eMV for α-particles. In modem conditions the photographic method provides a powerful and reliable instrument for nuclear research.

Electrostatic Generator for Nuclear Research at M.I.T.

The electrostatic generator previously located at Round Hill has been transferred to the M.I.T. grounds in Cambridge. The present generator construction and also a high voltage accelerating tube mounted vertically in one of the columns are described. An account is given of experience with the acceleration of positive ion and electron beams and with the x-ray bombardment of indium, beryllium, and deuterium.

A Neutron Generator for Biological Research

A neutron generator is described which has been built for biological research. It embodies a Cockcroft and Walton circuit to generate 400 kV and an ion tube fitted with a low-voltage arc for the bombardment of deuterium by deuterons. A film of deuterium paraffin-wax on copper, cooled by running tap water, is used as the target. Materials and apparatus cost £600, the shed to house it £150, and subsequent maintenance £80 per annum. Two physicists and a mechanic spent two years in the building and improvement of the generator.