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Ionization in positive ion sheaths

Morse, Philip M. and Uyterhoeven, W. (1928) Ionization in positive ion sheaths. Physical Review, 31 (5). pp. 827-832. ISSN 0031-899X. doi:10.1103/PhysRev.31.827.

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It was found that the positive ion current to a plane auxiliary collector placed in a neon discharge had about twice the value expected from the equations of Langmuir and Mott-Smith. This increase must be due to an ionization within the sheath surrounding the electrode or to an emission of electrons from the surface of the electrode. Four different possible causes of the increase are analyzed and relations between the voltage drop V, total current to the collector i, and sheath thickness x are obtained. Comparison with data shows that the increase in i is probably caused by the ionization of the metastable atoms within the sheath by radiation from the discharge. The relations; V = A(Bx^(4/3) + Cx^(8/3)), and i = (i0 + I0x^2)/2 hold, and check fairly well with the three experimental curves. Considerations of atomic energy states of the metastable atoms show that this ionization would be most marked in the noble gases, and almost nonexistant in mercury vapor, which was the gas investigated by Langmuir and Mott-Smith.

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Additional Information:©1928 The American Physical Society. Received February 1928. The writers wish to express their appreciation of the considerable aid rendered by Professor K.T. Compton in the preparation of this paper, and of the kindness of Doctor G. Holst, Director of the Philips Laboratory, for his permission to make use of the experimental data. [P.M.M. was a] Fellow in Physics at Princeton University. [W.U. was a] Fellow of the C.R.B. Educational Foundation at California Institute of Technology.
Issue or Number:5
Record Number:CaltechAUTHORS:MORpr28
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:8765
Deposited By: Tony Diaz
Deposited On:15 Sep 2007
Last Modified:08 Nov 2021 20:53

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