Letter | Published:

Neutron ‘Flux’

Naturevolume 191page60 (1961) | Download Citation



IT is the title, not the definition, of ‘neutron flux’ which is ambiguous, particularly the application of a vector term to a scalar quantity. The title should imply some connexion with the flow of neutrons ; in fact, as the velocities are integrated regardless of direction, the function defines the rate of generation of neutron track-lengths per unit volume at a given point. This is important in reaction problems because, as the elementary particles are treated as spherical and hence presenting a fixed cross-section to any neutron, it measures the collision potential. It is nothing whatever to do with the flow of neutrons, except in such special cases as collimated beams or by indirect calculation when the distribution pattern has been determined ; yet the phrase gives this impression and misleads many entrants to the nuclear field.

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  1. College of Advanced Technology, Gosta Green, Birmingham, 4

    • K. L. STRETCH


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