Powerful Neutron Source Research Articles

On magnetically confined plasmas used as neutron sources

It may become possible to create powerful neutron sources from a number of magnetic plasma confinement schemes being investigated in fusion research. Among the one- and two- energy-component plasmas discussed so far, special attention is drawn in this paper to quasi-static systems such as the Spherator with magnetically shielded supports, as well as to rotating plasma systems such as the closed Tornado bottle and open bottles. Provided that sufficiently high ion and electron temperatures can be reached, these systems may be operated at higher plasma densities and smaller dimensions than those of mirror and Tokamak neutron sources.

On the behaviour of slow neutrons in water and paraffin

The yield of a powerful neutron source may be measured in a simple way by means of a very thin detector of slow neutrons placed in a hydrogenated substance surrounding the source. Some of the quantities used in the calculations are discussed in this paper, such as the average path δ of a neutron in the thin detector and the average number N of collisions before capture. The discussion of the latter quantity lead to the question of the reflection coefficient β (albedo) of a plane boundary. The value of β was found by elementary considerations.

Points from Foregoing Letters

BY means of a powerful source of neutrons (half a gram of radium mixed with beryllium) Prof. J. C. McLennan, Mr. L. G. Grimmett and Mr. J. Read have produced measurable radioactivity in the elements molybdenum, palladium, tantalum, tungsten and platinum. They have determined with fair accuracy the radioactive life-periods thus induced in these elements.