This volume is the proceedings of the Hiroshima Symposium on Elementary Excitations in Quantum Fluids, which was held on August 17 and 18, 1987, in Hiroshima, Japan, and was attended by thirty-two scientists from seven countries. Quantum fluids have been the subject of intense study as a consequence of their superfluid properties at very low temperatures. Elementary excitations in them are an important concept about which many important discoveries have been made in recent years. This symposium was arranged by a group of physicists from Hiroshima University to provide an opportunity to discuss these recent developments. It was conceived as a satellite conference of the 18th International Conference on Low Temperature Physics (LT 18), which was held in Kyoto, August 20-26, 1987. Emphasis was placed on the dynamic structures and correlations of ele mentary excitations, which resulted in invited speakers being selected from this field. However, enthusiastic contributors reported notable new results on various other aspects of the elementary excitations, which made the sympo sium lively and successful. It is our great satisfaction to present this volume, which includes papers of good quality and originality. We thank all the parti cipants for their cooperation throughout this symposium, and for preparing their manuscripts within a reasonable time.

Klappentext

This book reviews recent developments in the study of elementary excitations in quantum fluids such as superfluid helium-4. New findings and considerable advances have been achieved in recent years in this area. The book covers such subjects as the theoretical derivation of the dispersion relation of the elementary excitations, neutron inelastic scattering and Raman scattering studies of the dispersion and interactions of the elementary excitations, excitations in helium films, ripplon excitations, vortex excitations, quantum evaporation and interactions of ultracold neutrons with elementary excitations.

Inhalt
I Theory of Liquid 4He at Finite Temperatures.- Microscopic Theory of Strongly Coupled Boson Quantum Fluids.- Elementary Excitations in Bose-Condensed Liquids and Gases at Finite Temperatures.- II Experimental Study of Elementary Excitations: Raman Scattering and Neutron Scattering.- Raman Scattering of Liquid 4He.- Polarization Study of Raman Scattering from Quantum Fluids.- Temperature Dependence of S(Q, ?) for Liquid 4He.- Upscattering of Ultra-Cold Neutrons (UCN) by Excitations in Superfluid 4He.- Excitations in 4He Films.- III Theoretical Study of Elementary Excitations and Related Properties: Raman Scattering and the Dynamic Structure Factor S(k, ?).- Theory of Inelastic Light Scattering from 4He.- Effect of the Three-Excitation States on the Raman Scattering from Superfluid 4He.- Reflections on Excitations in Superfluid Helium.- On Pitaevskii's Branch near the Two-Roton Threshold at Finite Temperatures.- Determination of the Roton-Maxon Interaction.- Two-Particle Excitations and Pair Correlations in He-II.- Two-Component Character of S(k, ?) in Superfluid 4He.- Theory of Temperature Dependence of Elementary Excitation Energy.- Eulerian and Lagrangian Phonons.- IV Quantum Evaporation.- Long Lifetime Excitations in 4He.- V Vortices, Ripplons and Ions.- Vortex Excitations and the Superfluid ? Transition.- Inhibition of Vortex Nucleation by Phonons in He II.- Ions and Electrons Trapped at the Surface of Superfluid Helium: Probes of the Study of Ripplons?.- Excitation Emission from Ions Moving at Supercritical Velocities in He II.- Index of Contributors.