[PDF] Angular Distribution Of Neutrons From Targets Bombarded By 190 Mev Deuterons eBook

Author : William J. Knox
Publisher :
Page : 30 pages
File Size : 42,86 MB
Release : 1950
Category : Bismuth
ISBN :

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Relative neutron yields in the forward direction from various target elements bombarded with 350 Mev protons and 190 Mev deuterons have been measured. Bismuth fission chambers with a threshold of about 50 Mev were used to detect the high energy neutrons. The actual flux of protons or deuterons traversing each target was determined from the activities induced in graphite monitors attached to the target. When a deuteron beam is used, the neutron yields for light elements agree with the values predicted by the deuteron stripping theory. For the heavy elements the observed values are fitted best by adding a function proportional to Z-sq to the stripping theory values. This may be interpreted as evidence for the production of high energy neutrons by the electric field disintegration of the deuteron. The neutron yields from the proton beam vary approximately as (A - Z)(exp(2/3)) for target elements from C to U. This indicates that the heavy elements are not completely transparent to 350 Mev protons. Beryllium has an anomalous neutron yield 50% higher than that for C. Calculations and measurements on the problem of multiple traversals of beam particles through thin targets are presented.

Author :
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Page : pages
File Size : 20,46 MB
Release : 1947
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Previous experimental work by Helmholz, McMillan, and Sewell has shown that a narrow beam of high energy neutrons is produced when a beam of 190 Mev deuterons strikes a thin target. The mechanism for the production of the eutrons has been discussed by Serber, who describes a process in which the proton in the deuteron strikes the edge of nucleus in the target and is stripped off, while the neutron misses and continues on its way. It is to be expected that an equal umber of high energy protons are produced by stripping processes in which it is the neutron that hits the nucleus. These high energy protons have been detected by (1) carbon activation, and (2) photographic plates. Both methods give energy distributions in agreement with the energy distribution predicted for protons produced by the stripping process.

Author : Larry Schecter
Publisher :
Page : 96 pages
File Size : 50,38 MB
Release : 1953
Category : Beryllium
ISBN :

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An investigation has been made of the angle and energy distributions of the high energy charged particles which emerge from beryllium, carbon, and uranium nuclei bombarded by 190 Mev deuterons. The results indicate that the yields can be explained as primarily due to two kinds of processes; nucleon-nucleon interactions, and stripping. Under this assumption, the total stripping cross section has been determined to be 0.35 ℗± 0.03 barns for the lighter elements and 2.6 ℗± 0.4 barns for uranium. These values suggest an A2/3 dependence for this cross section.