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- Newsgroups: sci.physics.fusion
- Path: sparky!uunet!seas.smu.edu!vivaldi!aslws01!aslss01!terry
- From: terry@asl.dl.nec.com
- Subject: Was sononluminescence _already_ solved, or not?
- Message-ID: <1993Jan5.225833.29067@asl.dl.nec.com>
- Originator: terry@aslss01
- Sender: news@asl.dl.nec.com
- Nntp-Posting-Host: aslss01
- Organization: (Speaking only for myself)
- Date: Tue, 5 Jan 1993 22:58:33 GMT
- Lines: 54
-
-
- Hi folks,
-
- OK, can someone address the timing issue here? When exactly does the effect
- of sonoluminescence occur during the cavitation cycle? How well is that
- timing really known (and by what methods)?
-
-
- From reference list Steven Jones provided I have this short quote:
-
- > D.F. Gaitan, L.A. Crum, C.C. Church, R.A. Roy,
- > "Sonoluminescence and bubble dynamics for a single, stable, cavitation
- > bubble," J. Acoust. Soc. Am. 91(6): 3166 (June 1992)
- >
- > "High-amplitude radial pulsations of a single gas bubble in several
- > glycerine and water mixtures have been observed in an acoustic stationary
- > wave system at acoustic pressure amplitudes on the order of 150 kPa (1.5
- > atm) at 21-25 kHz. Sonoluminescence (SL), a phenomenon generally attributed
- > to the high temperatures generated during the collapse of cavitation bubbles,
- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
- > was observed as short light pulses occurring once every acoustic period."
- >
- > "Despite the extensive amount of research done on both acoustic cavitation
- > and SL, many important questions relating to the nature and dynamics of
- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
- > these phenomena remain unanswered."
- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-
- From Dale Bass in <1993Jan5.180115.17549@murdoch.acc.Virginia.EDU> I have:
-
- > ... in stable cavitation in acoustical fields, the sonoluminescence occurs
- > shortly after the bubble reaches maximum radius (i.e. just as the bubble
- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
- > starts its inward cycle. Keep in mind that in stable sonoluminescence,
- > the bubble itself does not completely collapse.). This implies that the
- > sonoluminescence is mediated by a strong shock in the vapor itself (See
- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
- > Barber and Putterman PRL: 69:3839 (1992) among others), ...
-
-
- Sooo... Am I trying vainly to solve a pretty-much-fully-understood problem?
-
- If it's rock solid that the luminescent pulse occurs in the central void just
- as the surface of the a vapor-filled bubble twitches inward, then what's to
- solve? It would indeed have to be a vapor-filled bubble (not void), and it
- would indeed _have_ to be a shock wave, not a surface implosion.
-
- So again, has sonoluminiscence _already_ been solved, or not?
-
-
- Cheers,
- Terry Bollinger
-
-