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On the annihilation radiation of the positron

Published online by Cambridge University Press:  24 October 2008

Otto Klemperer
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Extract

Boron and carbon activated by diplon and proton bombardment have been used as positron emitting sources in experiments on the annihilation radiation.

By coincidence counting with two Geiger-Müller tubes it has been established that the radiation is emitted in pairs.

By the coincidence method of Becker and Bothe it has been shown that the annihilation radiation consists only of “soft” quanta.

By ordinary absorption measurements it has been shown that the annihilation radiation is homogeneous with a hardness corresponding to 0·5 million e-volt.

Type
Research Article
Information
Mathematical Proceedings of the Cambridge Philosophical Society , Volume 30 , Issue 3 , July 1934 , pp. 347 - 354
Copyright
Copyright © Cambridge Philosophical Society 1934

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References

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† I am very much indebted to Dr E. T. S. Walton for preparing several sources.

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† The best resistance was here 3 × 109ω, both 2 × 109 and 4 × 109ω were less satisfactory. Since the counter had no “flat place” in its count-voltage curve, particular care was taken to hold the voltage applied to the tube constant.

* The number of positrons emitted from the source was measured by means of a tube counter provided with a thin mica window. A small correction was made to allow for the reflection of positrons from the graphite. I am indebted to Mr C. W. Gilbert for the loan of the tube counter.

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