The anomalous dispersion associated with about 20 absorption lines relating three of the four (n+1) s and the ten (n+1) p levels in the first spectra of neon, argon and krypton has been quantitatively examined by means of the "hook method" in which a low pressure, low current discharge has been used in conjunction with a stigmatised Eagle spectrograph and a Mach-Zehnder interferometer. Details of the design, construction and adjustment of the latter are given. Argon has been most thoroughly considered but relative oscillator strengths and transition probabilities for lines with a common lower level are presented for each of the three gases. Values of these quantities relative to that of one line have been obtained by combining the anomalous dispersion data with the population relations derived from relative intensity measurements. Absolute values have been estimated by fixing an absolute f-value for this reference line from f-sum rule considerations'. Agreement has been obtained with previous results where they exist. The rather different configuration of the energy states of krypton as compared with neon and argon has been reflected in the appearance of • anomalous dispersion in a much smaller proportion of the equivalent s - p lines. Transition probabilities are given for eight krypton lines. The relative populations of the s states have been considered both on the grounds of the relative intensity measurements and from the f-sum data. A mean specific excitation temperature relating the s and ground levels has been evaluated in each case, and, together with reversal temperature studies in the case of argon, has shown the general absence of thermodynamic equilibrium in the plasma.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:602163 |
| Date | January 1962 |
| Creators | Chamberlain, John Ernest |
| Publisher | Imperial College London |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/10044/1/13657 |
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