Book contents
- Frontmatter
- Dedication
- Contents
- Preface
- Part One Preparing the Way
- Part Two Broadening Theory
- Part Three Atmospheric Spectra
- Part Four The Background
- Appendix 1 State Space
- Appendix 2 Product Space
- Appendix 3 Projectors
- Appendix 4 Vector Operators
- Appendix 5 Quantum Dynamics
- Appendix 6 Scattering Theory
- Appendix 7 Resolvent Methods
- Appendix 8 Linear Response
- Appendix 9 Correlation Function
- Appendix 10 Complex Time
- Appendix 11 Absorption
- Appendix 12 Multipole Moments
- Appendix 13 Angular Momentum
- Appendix 14 The Wigner–Eckart Theorem
- Appendix 15 Reduced Amplitudes
- Appendix 16 Units and Other Matters
- Appendix 17 Plasma Spectra: Pointers
- Notes
- References
- Index
Part One - Preparing the Way
Published online by Cambridge University Press: 26 June 2020
- Frontmatter
- Dedication
- Contents
- Preface
- Part One Preparing the Way
- Part Two Broadening Theory
- Part Three Atmospheric Spectra
- Part Four The Background
- Appendix 1 State Space
- Appendix 2 Product Space
- Appendix 3 Projectors
- Appendix 4 Vector Operators
- Appendix 5 Quantum Dynamics
- Appendix 6 Scattering Theory
- Appendix 7 Resolvent Methods
- Appendix 8 Linear Response
- Appendix 9 Correlation Function
- Appendix 10 Complex Time
- Appendix 11 Absorption
- Appendix 12 Multipole Moments
- Appendix 13 Angular Momentum
- Appendix 14 The Wigner–Eckart Theorem
- Appendix 15 Reduced Amplitudes
- Appendix 16 Units and Other Matters
- Appendix 17 Plasma Spectra: Pointers
- Notes
- References
- Index
Summary
A brief overview is given of many topics that are covered later, followed by a detailed plan of the book. The concern is with interactions that take place between molecular dipoles in an equilibrium gas when probed by an externally sourced electromagnetic wave train. This will lead to the appearance of otherwise sharp spectral lines that may be broadened in various ways. After a brief mention of the early ideas of Lorentz and Weisskopf, the discussion moves to the real starting point for this book, which is the idea that the line shape will be determined by the fluctuating response of the active dipole to molecular collisions. Three broadening effects are distinguished. Firstly, an elastic collision at the radiating molecule may cause a sudden change in the phase of the wave train. Secondly, where an elastic collision exerts a torque on the radiator, there may be an elastic reorientation and a sudden change in the wave train amplitude. Thirdly, an inelastic collision may lead to a sudden change in the frequency of the wave train, and, if these collisions are frequent enough, there may also be interference, or coupling, between the lines as they are broadened.
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- Information
- Pressure Broadening of Spectral LinesThe Theory of Line Shape in Atmospheric Physics, pp. 1 - 2Publisher: Cambridge University PressPrint publication year: 2020