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词条 Second sound
释义

  1. Second sound in helium II

  2. Second sound in other media

  3. Applications

  4. See also

  5. References

  6. Bibliography

Second sound is a quantum mechanical phenomenon in which heat transfer occurs by wave-like motion, rather than by the more usual mechanism of diffusion. This leads to a very high thermal conductivity. It is known as "second sound" because the wave motion of heat is similar to the propagation of pressure waves in air (sound).

Normal sound waves are fluctuations in the density of molecules in a substance;

second sound waves are fluctuations in the density of particle-like thermal excitations (rotons and phonons[1]).

Second sound can be observed in any system in which most phonon-phonon collisions conserve momentum.

This occurs in superfluids,[2] and also in

some dielectric crystals[3][4][5] when Umklapp scattering is small.

(Umklapp phonon-phonon scattering exchanges momentum with the crystal lattice, so phonon momentum is not conserved.)

Second sound in helium II

Second sound is observed in liquid helium at temperatures below the lambda point, 2.1768 K, where 4He becomes a superfluid known as helium II.

Helium II has the highest thermal conductivity of any known material (several hundred times higher than copper).[6] Second sound can be observed either as pulses or in a resonant cavity.[7]

The speed of second sound is close to zero near the lambda point, increasing to approximately 20 m/s around 1.8 K,[8] about ten times slower than normal sound waves.[9]

At temperatures below 1 K, the speed of second sound in helium II increases as the temperature decreases.[10]

Second sound is also observed in superfluid helium-3 below its lambda point 2.5 mK.[11]

Second sound in other media

Second sound has been observed in solid 4He and 3He,[12][13]

and in some dielectric solids such as Bi in the temperature

range of 1.2 to 4.0 K with a velocity of 780 ± 50 m/s,[14]

or NaF around 10 to 20 K.[15]

In 2019 it was reported that ordinary graphite exhibits "second sound" at 120 Kelvin.

This was both predicted theoretically and observed experimentally, and

was by far the hottest temperature at which second sound has been observed.

[16] However, this second sound is observed only at the microscale, because the wave dies out exponentially with

characteristic length 1-10 microns.

Therefore, presumably graphite in the right temperature regime has extraordinarily high thermal conductivity but only

for the purpose of transferring heat pulses distances of order 10 microns, and for pulses of duration on the order of 10 nanoseconds.

For more "normal" heat-transfer, graphite's observed thermal conductivity is less than that of, e.g, copper.

The theoretical models, however, predict longer absorption lengths would be seen in isotopically-pure graphite,

and perhaps over a wider temperature range, e.g. even at room temperature.

(As of March 2019, that experiment has not yet been tried.)

Applications

Measuring the speed of second sound in 3He-4He mixtures can be

used as a thermometer in the range 0.01-0.7 K.[17]

Oscillating superleak transducers (OST)[18] use second sound to locate defects in superconducting accelerator cavities.[19][20]

See also

  • Third sound

References

1. ^{{cite book | title = Transport Phenomena | last1 = Smith | first1 = Henrik | last2 = Jensen |first2 = H. Hojgaard | year = 1989 | publisher = Oxford University Press | isbn = 0-19-851985-0 | url = https://books.google.com/books?id=xPt9AAAAIAAJ | chapter = Section 4.3: Second Sound }}
2. ^{{cite journal | title = Second Sound: Waves of Entropy and Temperature | last = Srinivasan | first = R | journal = Resonance | volume = 3 |date=March 1999 | pages = 16–24 | url = http://www.ias.ac.in/resonance/Mar1999/pdf/Mar1999p16-24.pdf }}
3. ^{{cite journal | title = Second Sound: The Role of Elastic Waves | last = Srinivasan | first = R | journal = Resonance | volume = 4 |date=June 1999 | pages = 15–19 | url = http://www.ias.ac.in/resonance/June1999/pdf/June1999p15-19.pdf | doi=10.1007/bf02834631 }}
4. ^{{Cite journal | last1 = Prohofsky | first1 = E. | last2 = Krumhansl | first2 = J. | doi = 10.1103/PhysRev.133.A1403 | title = Second-Sound Propagation in Dielectric Solids | journal = Physical Review | volume = 133 | issue = 5A | pages = A1403 | year = 1964 | pmid = | pmc = |bibcode = 1964PhRv..133.1403P }}
5. ^{{Cite journal | last1 = Chester | first1 = M. | title = Second Sound in Solids | doi = 10.1103/PhysRev.131.2013 | journal = Physical Review | volume = 131 | issue = 5 | pages = 2013–2015 | year = 1963 | pmid = | pmc = |bibcode = 1963PhRv..131.2013C }}
6. ^{{cite report | title = Superfluid helium as a technical coolant | last = Lebrun | first = Phillipe | date = July 17, 1997 | page = 4 | type = LHC-Project-Report-125 | publisher = CERN | url = http://cdsweb.cern.ch/record/330851/files/lhc-project-report-125.pdf }}
7. ^{{Cite journal | last1 = Van Der Boog | first1 = A. G. M. | last2 = Husson | first2 = L. P. J. | last3 = Disatnik | first3 = Y. | last4 = Kramers | first4 = H. C. | title = Experimental results on the velocity of second sound and the viscosity in dilute 3He-4He mixtures | doi = 10.1016/0378-4363(81)90176-5 | journal = Physica B+C | volume = 104 | issue = 3 | pages = 303–315 | year = 1981 | pmid = | pmc = |bibcode = 1981PhyBC.104..303V }}
8. ^{{Cite journal | last1 = Wang | first1 = R. T. | last2 = Wagner | first2 = W. T. | last3 = Donnelly | first3 = R. J. | year = 1987 | title = Precision second-sound velocity measurements in helium II | journal = Journal of Low Temperature Physics | volume = 68 | issue = 5–6 | pages = 409–417 | bibcode = 1987JLTP...68..409W | doi = 10.1007/BF00682305}}
9. ^{{Cite journal | last1 = Lane | first1 = C. | last2 = Fairbank | first2 = H. | last3 = Fairbank | first3 = W. | doi = 10.1103/PhysRev.71.600 | title = Second Sound in Liquid Helium II | journal = Physical Review | volume = 71 | issue = 9 | pages = 600–605 | year = 1947 | pmid = | pmc = |bibcode = 1947PhRv...71..600L }}
10. ^{{Cite journal | last1 = De Klerk | first1 = D. | last2 = Hudson | first2 = R. | last3 = Pellam | first3 = J. | title = Second Sound Propagation below 1°K | doi = 10.1103/PhysRev.93.28 | journal = Physical Review | volume = 93 | pages = 28–37 | year = 1954 | pmid = | pmc = |bibcode = 1954PhRv...93...28D }}
11. ^{{Cite journal | last1 = Lu | first1 = S. | last2 = Kojima | first2 = H. | doi = 10.1103/PhysRevLett.55.1677 | title = Observation of Second Sound in Superfluid ^{3}He-B | journal = Physical Review Letters | volume = 55 | issue = 16 | pages = 1677–1680 | year = 1985 | pmid = 10031890| pmc = |bibcode = 1985PhRvL..55.1677L }}
12. ^{{Cite journal | last1 = Ackerman | first1 = C. | last2 = Bertman | first2 = B. | last3 = Fairbank | first3 = H. | last4 = Guyer | first4 = R. | title = Second Sound in Solid Helium | doi = 10.1103/PhysRevLett.16.789 | journal = Physical Review Letters | volume = 16 | issue = 18 | pages = 789–791 | year = 1966 | pmid = | pmc = |bibcode = 1966PhRvL..16..789A }}
13. ^{{Cite journal | last1 = Ackerman | first1 = C. | last2 = Overton | first2 = W. | doi = 10.1103/PhysRevLett.22.764 | title = Second Sound in Solid Helium-3 | journal = Physical Review Letters | volume = 22 | issue = 15 | pages = 764–766 | year = 1969 | pmid = | pmc = |bibcode = 1969PhRvL..22..764A }}
14. ^{{Cite journal | last1 = Narayanamurti | first1 = V. | last2 = Dynes | first2 = R. | doi = 10.1103/PhysRevLett.28.1461 | title = Observation of Second Sound in Bismuth | journal = Physical Review Letters | volume = 28 | issue = 22 | pages = 1461–1465 | year = 1972 | pmid = | pmc = |bibcode = 1972PhRvL..28.1461N }}
15. ^{{Cite journal | last1 = Jackson | first1 = H. | last2 = Walker | first2 = C. | last3 = McNelly | first3 = T. | title = Second Sound in NaF | doi = 10.1103/PhysRevLett.25.26 | journal = Physical Review Letters | volume = 25 | pages = 26–28 | year = 1970 | pmid = | pmc = |bibcode = 1970PhRvL..25...26J }}
16. ^{{Cite journal | last1 = Huberman | first1 = S. | last2 = Duncan | first2 = R.A. | doi = 10.1126/science.aav3548 | title = Observation of second sound in graphite at temperatures above 100 K | journal = Science | year = 2019 | pmid = | pmc = |bibcode = }}
17. ^{{Cite book | last1 = Pitre | first1 = L. | chapter = The Comparison between a Second-Sound Thermometer and a Melting-Curve Thermometer from 0.8 K Down to 20 mK | doi = 10.1063/1.1627108 | title = AIP Conference Proceedings | volume = 684 | pages = 101–101 | year = 2003 | pmid = | pmc = }}
18. ^{{Cite journal | last1 = Sherlock | first1 = R. A. | title = Oscillating Superleak Second Sound Transducers | doi = 10.1063/1.1684354 | journal = Review of Scientific Instruments | volume = 41 | issue = 11 | pages = 1603–1609 | year = 1970 | pmid = | pmc = |bibcode = 1970RScI...41.1603S }}
19. ^{{cite journal | journal = ILC newsline | url = http://newsline.linearcollider.org/2011/04/21/the-sound-of-accelerator-cavities/ | last = Hesla | first = Leah | title = The sound of accelerator cavities | date = 21 April 2011 | accessdate = 26 October 2012 }}
20. ^{{Cite journal | last1 = Quadt | first1 = A. | last2 = Schröder | first2 = B. | last3 = Uhrmacher | first3 = M. | last4 = Weingarten | first4 = J. | last5 = Willenberg | first5 = B. | last6 = Vennekate | first6 = H. | doi = 10.1103/PhysRevSTAB.15.031001 | title = Response of an oscillating superleak transducer to a pointlike heat source | journal = Physical Review Special Topics: Accelerators and Beams | volume = 15 | issue = 3 | year = 2012 | pmid = | pmc = |arxiv = 1111.5520 |bibcode = 2012PhRvS..15c1001Q }}

Bibliography

  • Sinyan Shen, Surface Second Sound in Superfluid Helium. PhD Dissertation (1973). http://adsabs.harvard.edu/abs/1973PhDT.......142S
  • V. Peshkov, "'Second Sound' in Helium II," J. Phys. (Moscow) 8, 381 (1944)
  • U. Piram, "Numerical investigation of second sound in liquid helium," Dipl.-Ing. Dissertation (1991). Retrieved on April 15, 2007.

2 : Quantum mechanics|Thermodynamics
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