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Wheatley, J.C. Abel, William Russell 2011-05-20T15:51:27Z 2011-05-20T15:51:27Z 10000-01-01 1966 The propagation of sound in liquid He3 was observed at a pressure of 0.32 atm and at fre~quencies of 15.4 and 45.5 MHz down to a temperao 0 -3 0 . ture T* of 2m K (1m K = 10 K) on the temperature scale va11d for the Curie-law magnetic susceptibility of powdered cerium magnesium nitrate in the form of a right circular cylinder with diameter equal to height. The results of the measurements have been published by the author, A. C. Anderson, and J. C. Wheatley. * As the temperature was increased, the sound attenuation increased, went through a max.imum, and then decreased. At low temperatures, the attenuation was proportional to T~,(2 but independent of frequency, and at higher temperatures it was proportional to W 2/T*2, where w is the angular frequency of the sound. The temperature at which max.imum attenuation occurred was o 0 11.3m K for the frequency of 15.4 MHz and was 19.3m K for 45.5 MHz. The velocity of the sound was found to be relatively temperature independent at high and low temperatures but near the attenuation maximum the velocity changed by 3.5 ± 0.3 percent. The results of the measurements are predicted by the Landau theory of a Fermi liquid, the velocity change and the temperature dependence of the attenuation coefficient at low temperatures being explained by the propagation of a new mode of sound, called zero sound. The velocity change is in quantitative agreement with the theory. The attenuation of zero sound is about 35% larger than that predicted by theory, but could be explained by a shorter collision time between quasiparticles in the zero sound regime, The frequency and temperature dependence of the attenuation coefficient at higher temperatures are those predicted for ordinary hydrodynamic sound. Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-05-20T15:51:27Z No. of bitstreams: 1 1966_abel.pdf: 2033513 bytes, checksum: 62b66bd69daa0cfa1c9fa5db5896e520 (MD5) Made available in DSpace on 2011-05-20T15:51:27Z (GMT). No. of bitstreams: 1 1966_abel.pdf: 2033513 bytes, checksum: 62b66bd69daa0cfa1c9fa5db5896e520 (MD5) Previous issue date: 1966 Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-05-20T15:51:27Z Item is restricted indefinitely. Restriction data tranferred 2014-07-01T11:13:13-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis Thesis U of I Only 6178871 http://hdl.handle.net/2142/23983 en 1966 William Russell Abel sound propagation zero sound liquid He3 Curi-law magnetic susceptibility Propagation of zero sound in liquid He3 Dissertation / Thesis text Physics Physics University of Illinois at Urbana-Champaign Dissertation Ph.D.