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Measurement of Relative gf-Values and Collisional Damping Constants for Spectral Lines of Neutral Calcium


Olsen, Kenneth Harold (1957) Measurement of Relative gf-Values and Collisional Damping Constants for Spectral Lines of Neutral Calcium. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/2584-MH64.


The relative gf-values for 107 lines in 34 multiplets of Ca I between [lambda] 2990 and [lambda] 6720 have been derived from the photographic photometry of absorption lines excited in an electric furnace. All the lines arise from low terms whose excitation potentials range from 0.0 to 3.0 e.v. A brief discussion of the method used for making the measurements is given, together with an outline of the theoretical relationships which are required to reduce the measurements to relative gf-values. The various components of the experimental apparatus are described in some detail. In the second part, some preliminary studies have been made on the pressure broadening of Fe I and Ca I absorption lines in electric furnace spectrograms. By using relative gf-values for lines of these elements, empirical curves of growth have been constructed from which the collisional damping constants for some of the lines are derived. The experimental damping constants are compared with those calculated from the available theories of pressure broadening. The results indicate that observations of broadened absorption lines in furnace spectra may prove useful in determining collisional damping constants for many lines of astrophysical interest.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:(Physics and Astronomy)
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Minor Option:Astronomy
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • King, Robert Burnett
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 January 1957
Record Number:CaltechETD:etd-07152004-143851
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:2894
Deposited By: Imported from ETD-db
Deposited On:16 Jul 2004
Last Modified:13 Oct 2023 19:45

Thesis Files

PDF (Olsen_kh_1957.pdf) - Final Version
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