Doctoral Dissertations


Victor Pol


"The UMR heavy-ion energy-loss spectrometer has been modified to study the angular dependence of elastic and inelastic scattering for 25-140 keV He+ incident on He. The data were obtained as energy-loss spectra at angles from 0 to 7.3 x 10-3 rad (c.m.) with energy-loss resolution of 0.6 to 1.0 eV and angular resolution of 1.2 x 10-3 to 2.4 x 10-3 rad (c.m.). From the spectra we have calculated average differential cross sections for elastic scattering, direct excitation of the individual He(n=2) states and direct excitation of the He+(n=2) states. By integrating the differential cross sections we found the total cross section for excitation of the He(n=2) states to be 20 x 10-18 cm2 at 25 keV (lab) decreasing to 7 x 10-18 cm2 at 140 keV. At incident lab energies below 100 keV the He(23s) and He(23P) states dominate the He(n=2) structure at angles close to zero, while the He(21P) state dominates at larger angles. The contribution of the He(21S) state remains below 25% at all angles and energies. The results are compared with previous measurements on this apparatus, with electron capture measurements in the same energy range, and with results of others at lower energies. A comparison is also made with impact parameter calculations and with molecular orbital calculations on the angular dependence of the excitation cross sections"--Abstract, pages ii-iii.


Park, John T.

Committee Member(s)

Anderson, Richard A.
Snow, William R.
Peacher, Jerry
Hicks, Troy L.



Degree Name

Ph. D. in Physics


National Science Foundation (U.S.)


University of Missouri--Rolla

Publication Date



vii, 88 pages

Note about bibliography

Includes bibliographical references (pages 85-87).


© 1973 Victor Pol, All rights reserved.

Document Type

Dissertation - Restricted Access

File Type




Library of Congress Subject Headings

Scattering (Physics)
Heavy ion collisions
Electrons -- Capture

Thesis Number

T 2818

Print OCLC #


Electronic OCLC #


Link to Catalog Record

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