Frank Irons (University of New South Wales Australia): In my opinion Mr. P. Meier has done very good work. His thesis is well presented and is worthy of a Ph. D. As I see it, his contribution to learning in his field, of shock tube physics, is twofold, viz.
(i) the development of existing theories to derive values for the polarizability of argon and helium bound states and to show how the contribution of the excited state electrons to the refractivity may be incorporated with the ions and free electrons into two items, the "effective electron density" and the "effective ion density (He is able to interpret his results to measure the "effective electron density" and the "effective ion density"), and
(ii) the refinement of techniques for interpreting interferograms leading to a measurement of the polarizability. In particular, he has made extensive use of electronic data redction techniques, and it is pleasing to see how thoroughly he has documented this work in his reports Physics of Fluids ANU PF 11. My feeling is that he has developed the technique of interferometry to about its limit.

Thomas J. Mcllrath (HARVARD COLLEGE OBSERVAT0RY): I would like to have you convey to Mr. Meier my pleasure in reading his thesis. It was enlightening and enjoyable to see such a vigorous attempt at the analysis of the refractivity of a shock produced plasma. I feel that the subject of the thesis is of interest and significance in atomic physics and plasma physics and that Mr. Meier has successfully employed the techniques of interferometry in the study of this problem. The theoretical and experimental problems involved in this field are large and complicated and precluded a definitive solution but Mr. Meier has carried out a very nice combination of theoretical and experimental programs which significantly adds to our tools in this field. He has established the feasibility of interferometry on high temperature plasmas as a diagnostic for both plasma conditions and atomic parameters. The validity of the technique is supported by the agreement with his theoretical calculations. This work should lead to a much more thorough and time consuming study than is feasible in" a dissertation' study. I recommend that Mr. Meier be unconditionally admitted to the Degree of Doctor of Philosophy [link to my work 2010/11 in overcoming the short-comings of philosophy in terms of doing justice to the relationship between the collective and the indivdual human being...]

Dr. W.I.B. Smith (Sydney University): The thesis was well presented to the required standards, and needed only minor corrections for a very few misprints, which were pointed out to the candidate at the oral examination. Most of these he had found and corrected himself. In my opinion this work has added to the understanding of these plasmas and will be of value in future work on-the shock tube facilities and consequently represents a sufficiently substantial contribution to learning as to earn the award of the Ph.D. degree by the A.N.U. The material of this thesis is detailed and involved and I would recommend the publication of a short general account of this work, of such nature and length as to indicate the general results achieved, the methods of calculations used, and with an outline of the experimental confirmation obtained. I congratulate the candidate on his performance at the oral examination. I was fully satisfied with his general knowledge and his appreciation of the matters discussed in his thesis. I recommend that he be admitted to the Ph.D. degree in the Australian National University.