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The secondary emission from a nickel surface due to slow positive ion bombardment

Klein, A. L. (1925) The secondary emission from a nickel surface due to slow positive ion bombardment. Physical Review, 26 (6). pp. 800-806. ISSN 0031-899X. doi:10.1103/PhysRev.26.800.

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The apparatus was arranged so that positive ions from a heated Mo strip coated with aluminum phosphate, were accelerated radially through slots in shields A and B, and a wider slot in an electrode C to the target T, from which the secondary emission to the electrode C was measured. The parts A, B, C and T were all concentric nickel cylinders, symmetrically placed about the emitter. If the potential of the emitter is made zero and the accelerating potential V1, when the collector is at zero potential only reflected positives are collected. As the potential is increased, secondaries also reach it, the net negative charge increasing until a saturating potential 2V1 is reached, when all negatives and no positives are collected. The percentage saturated secondary electron emission was found to increase approximately as the square of the primary ion energy, reaching 22 percent of the primary ion current, for primary ions of energies corresponding to 380 volts. The curves show that large numbers of reflected positive ions have energies between zero and two volts, and there is also a group of reflected positive ions with energies approximately 0.9 of the primary energy.

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Additional Information:© 1925 The American Physical Society. Received 24 June 1925. The writer wishes to express his great indebtedness to Dr. Millikan for his help during the progress of this research. Also he wishes to thank Mr. G. A. Alles and Mr. A. L. Raymond for their help in preparing the aluminum phosphate used, and to express his deepest appreciation to Mr. W. Clancy and Mr. J. Pearson for their assistance in the design and construction of the apparatus used.
Issue or Number:6
Record Number:CaltechAUTHORS:KLEpr25
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:2440
Deposited By: Tony Diaz
Deposited On:04 Apr 2006
Last Modified:08 Nov 2021 19:47

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