Light from one sound-driven bubble carries argon spectral lines that put its temperature at up to 15,000 K (Flannigan and Suslick, Nature 2005). Each flash lasts from under 40 to over 350 picoseconds (Hiller, Putterman and Weninger, Physical Review Letters 1998), the bubble wall collapses faster than Mach 4 (Weninger, Barber and Putterman, Physical Review Letters 1997), and the plasma inside can hold more than 10²¹ electrons per cubic centimeter (Flannigan and Suslick, Nature Physics 2010). Bubbles in water are usually an engineering problem, as in our propeller cavitation statistics and bubble curtain statistics; held still in a standing sound wave, one bubble becomes a tabletop laboratory for extreme matter. We aggregated data from Nature, Nature Physics, Physical Review Letters, Physical Review E, Science, the Journal of the Acoustical Society of America (JASA), the Annual Review of Physical Chemistry, Ultrasonics Sonochemistry, and more than 20 other primary papers.
Most recent available data: much of the core measurement record dates from 1991 to 2014, and newer 2023 to 2026 work is mostly simulation. Each table flags the year.
TL;DR
- Argon emission temperatures in single-bubble sonoluminescence (SBSL) span 4,000-15,000 K (Flannigan and Suslick, Nature 2005).
- Electron density can be controlled over four orders of magnitude and exceed 10²¹ cm⁻³ (Flannigan and Suslick, Nature Physics 2010).
- Pressure in the bubble and its outgoing shock has a lower limit of 5500 bars (Holzfuss, Rüggeberg and Billo, Physical Review Letters 1998).
- Flash widths run from about 60 ps to more than 250 ps for air bubbles in water (Gompf et al., Physical Review Letters 1997).
- A 7.1 kHz air bubble emits 10^4-10^5 photons per pulse (Toegel et al., Physical Review Letters 2000).
- Stable light emission needs a driving pressure of about 1.2-1.5 atm and dissolved gas below 0.4% of saturation (Hilgenfeldt, Lohse and Brenner, Physics of Fluids 1996).
- About 1% noble gas in a nitrogen bubble boosts light output by over an order of magnitude (Hiller et al., Science 1994).
- Concentrated sulfuric acid made the emission nearly 3,000 times brighter than water (University of Illinois 2005).
- Bubble collapse can concentrate energy density by 12 orders of magnitude (Krimans, Ruuth and Putterman, Physical Review E 2025).
- Multi-bubble clouds in silicone oil gave an effective temperature of 5075 +/- 156 K (Flint and Suslick, Science 1991).
1. Bubble-Core Temperatures: What the Spectra Actually Measure
The headline number depends on what is being measured. Spectral lines (the narrow, element-specific peaks of light) report the temperature of the emitting shell, and argon lines in single bubbles in 85 wt% sulfuric acid gave 4,000-15,000 K (Flannigan and Suslick, Nature 2005). Continuum fits to the whole spectrum report something different, and the Putterman group at UCLA fitted bremsstrahlung (light given off when free electrons are deflected by ions) to a bubble driven at 1 MHz and inferred a 10⁶ degree plasma.
The spread between 10⁴ K and 10⁶ K is not a measurement error so much as a model choice. The 2002 Reviews of Modern Physics review by Brenner, Hilgenfeldt and Lohse found that the available data favor adiabatic heating at collapse, leading to partial ionization and thermal emission, and that shock waves inside the bubble do not appear to play a prominent role (University of Twente record of the review). The line and plasma diagnostics in the table below span 4,000 to 20,000 K; only continuum model fits reach 10⁶ degrees.
| Metric | Value | Source |
|---|---|---|
| Argon emission temperature, single bubble in concentrated aqueous sulfuric acid | 4,000-15,000 K | Flannigan and Suslick, Nature 2005 |
| Effective plasma temperature, single bubble in 85 wt% sulfuric acid | 7,000 to more than 16,000 K | Flannigan and Suslick, Nature Physics 2010 |
| Upper end of intracavity temperatures from single-bubble and bubble-cloud spectroscopy | up to 20,000 K | Suslick and Flannigan, Annual Review of Physical Chemistry 2008 |
| Peak temperature implied for helium bubbles by a plasma-quenching model | ≳20 eV | Hiller, Putterman and Weninger, Physical Review Letters 1998 |
| Bremsstrahlung fit for a single bubble driven at 1 MHz | 10⁶ degree transparent plasma | Camara, Putterman and Kirilov, Physical Review Letters 2004 |
| Xenon bubble turning into an opaque blackbody | below 10 000 K, at sub-liquid density | Kappus, Khalid, Chakravarty and Putterman, Physical Review Letters 2011 |
| Plasma temperature at maximum compression, bubble driven at 30 kHz | about 10,000 K | APS Physics 2014, reporting Bataller et al., Physical Review Letters 2014 |
Context: the University of Illinois press release for the 2005 paper quoted about 20,000 K, while the peer-reviewed abstract caps the argon-line range at 15,000 K. We cite the abstract value. Suslick also cautioned against directly comparing blackbody and argon-line temperatures, because they may come from different times and regions of the collapse (Physics Today 2005).
2. Pressures, Electron Densities, and the Plasma Inside
Temperature alone undersells how strange the interior is. The electron density inside a collapsing bubble can exceed 10²¹ cm⁻³ and be tuned over four orders of magnitude by the driving pressure (Flannigan and Suslick, Nature Physics 2010). The University of Illinois compared those densities with the ones generated by laser fusion experiments, and APS Physics notes that such plasmas form thousands of times per second and stay stable for days.
The opacity results matter most for theory. A laser-heated sonoluminescing plasma turned out to be 1000 times more opaque than the Saha equation (the textbook formula linking temperature to the fraction of ionized atoms in a dilute gas) predicts, which means dilute-plasma models do not apply. The pressure figures rest on shock imaging: an outgoing shock in the water puts a lower limit of 5500 bars on the pressure at collapse (Holzfuss, Rüggeberg and Billo, arXiv preprint of the PRL paper).
| Metric | Value | Source |
|---|---|---|
| Lower limit of pressure in the shock wave and in the bubble at collapse | 5500 bars | Holzfuss, Rüggeberg and Billo, Physical Review Letters 1998 |
| Intracavity pressures from spectrometric pyrometry and plasma diagnostics | several thousand bar | Suslick and Flannigan, Annual Review of Physical Chemistry 2008 |
| Plasma electron density in single bubbles in sulfuric acid | can exceed 10²¹ cm⁻³, controllable over four orders of magnitude | Flannigan and Suslick, Nature Physics 2010 |
| Number density estimated by probing with 3 ns laser pulses at 532 nm and 1064 nm | 2×10²¹ cm⁻³ | Bataller, Kappus, Camara and Putterman, Physical Review Letters 2014 |
| Opacity of the plasma compared with the Saha equation prediction | can be 1000 times more opaque | Khalid, Kappus, Weninger and Putterman, Physical Review Letters 2012 |
| Photon scattering length in a xenon bubble compared with what the observed opacity requires | 10 000 times too long | Kappus et al., Physical Review Letters 2011 |
| Heating and cooling rates inside a collapsing bubble | greater than 10¹² K s⁻¹ | Suslick and Flannigan, Annual Review of Physical Chemistry 2008 |
| Temperature rise when a nanosecond laser hits the sonoluminescing plasma | factor of 2, from its spectrum | Khalid et al., Physical Review Letters 2012 |
3. Flash Duration, Brightness, and Timing
The flash is too short for ordinary light detectors to resolve. Time-correlated single photon counting showed widths growing from about 60 ps at low gas concentration and low driving pressure to more than 250 ps near the upper threshold (Gompf, Günther, Nick, Pecha and Eisenmenger, Physical Review Letters 1997). Across other gas mixtures the range widened to under 40 to over 350 ps, with no change from ultraviolet to infrared (Hiller, Putterman and Weninger 1998).
That wavelength independence is the key clue, and it led the authors to propose a plasma that switches off as its temperature drops below the ionization potential. The photon budget is small. Lowering the drive to 7.1 kHz, which a 1999 model predicted would give brighter bubbles, still produced only 10^4-10^5 photons per pulse, because trapped water vapor soaked up the heat (Toegel, Gompf, Pecha and Lohse 2000).
| Metric | Value | Source |
|---|---|---|
| Pulse width of an air bubble in degassed water, from low to high gas concentration and drive | from about 60 ps to more than 250 ps | Gompf et al., Physical Review Letters 1997 |
| Flash width range across various gas mixtures in water | from under 40 to over 350 ps | Hiller, Putterman and Weninger, Physical Review Letters 1998 |
| Photons per pulse, air bubble driven at 7.1 kHz | 10^4-10^5, no brighter than at 20 kHz | Toegel et al., Physical Review Letters 2000 |
| Pulse width, air bubble driven at 7.1 kHz | approximately 150 ps, as long as at 20 kHz | Toegel et al., Physical Review Letters 2000 |
| Peak optical power of a single sonoluminescing bubble in water | over 30 mW | Hiller, Putterman and Barber, Physical Review Letters 1992 |
| Light emission before minimum radius, as a share of the acoustic period | 0.03% of the period | Barber and Putterman, Physical Review Letters 1992 |
| Bubble wall collapse speed, relative to the sound speed in the gas inside | faster than Mach 4 | Weninger, Barber and Putterman, Physical Review Letters 1997 |
| Flash timing and wall acceleration at minimum radius | flash within 500 ps of minimum radius, acceleration above 10^11 g | Weninger, Barber and Putterman, Physical Review Letters 1997 |
Outlier note: a 2025 experiment measured 3.50 ns and 3.45 ns flash widths at full width at half maximum, against 0.36 ns and 0.38 ns in its own simulation (Wang and Liang, Ultrasonics Sonochemistry 2025). The measured width is about 10 times the simulated one (3.50 / 0.36 = 9.7) and far above the photon-counting results in the table, a reminder that the detection method largely sets the number reported.
4. Driving Conditions and Bubble Size
The working window is narrow. Stable sonoluminescence only occurs at a forcing pressure amplitude of about 1.2-1.5 atm and a dissolved gas concentration below 0.4% of saturation (Hilgenfeldt, Lohse and Brenner, Physics of Fluids 1996). Outside that window, shape and diffusive instabilities take over, and the upper gas limit shrinks as the forcing rises.
The bubble itself is micron-scale. A 2025 model of an argon bubble trapped at an antinode (a point of maximum pressure swing in a standing sound wave) started at a 4.5 μm radius and shrank to 0.747744 μm at peak compression (Wang and Liang, Ultrasonics Sonochemistry 2025). The same standing-wave trap underpins the techniques in our acoustic levitation statistics, here pushed to the point of collapse.
| Metric | Value | Source |
|---|---|---|
| Driving conditions of the first stable single cavitation bubble, glycerine-water mixture | about 150 kPa (1.5 atm) at 21-25 kHz | Gaitan et al., JASA 1992 |
| Forcing pressure and dissolved gas window for stable sonoluminescence | P_a ~ 1.2-1.5 atm, gas below 0.4% of saturation | Hilgenfeldt, Lohse and Brenner, Physics of Fluids 1996 |
| Single-bubble cell conditions for photon and radical yield measurements | 52 kHz, 1.33 to 1.51 atm, 3 °C | Didenko and Suslick, Nature 2002 |
| Amount of reacting gas inside one bubble | typically below 10⁻¹³ mol | Didenko and Suslick, Nature 2002 |
| Measured local acoustic pressure at two adjacent antinodes, 27.312 kHz | about 1.205 atm and 1.198 atm | Wang and Liang, Ultrasonics Sonochemistry 2025 |
| Simulated ambient radius vs minimum radius at peak compression | 4.5 μm vs 0.747744 μm | Wang and Liang, Ultrasonics Sonochemistry 2025 |
| Fitted initial radii across five driving amplitudes from 1.416 to 1.565 bar, 25.34 kHz | 2.43 to 4.20 µm | Shen, Pflieger, Chen et al., Ultrasonics Sonochemistry 2023 |
| Maximum radius vs ambient radius in extreme collapses, and radius change during collapse | 10 to 20 times; a factor of over 100 | Krimans, Ruuth and Putterman, Physical Review E 2025 |
Context: the 2025 Physical Review E study states that bubble collapse can concentrate energy density by 12 orders of magnitude, and names liquid lithium as a candidate for greater concentration than water (Krimans, Ruuth and Putterman, arXiv version).
5. Spectral Lines and Noble-Gas Doping
Single-bubble light in water is broadband, with any spectral peak lying above 6 eV (Hiller, Putterman and Barber, Physical Review Letters 1992). Swapping water for concentrated sulfuric acid boosted the brightness of the spectra nearly 3,000 times and revealed discrete lines (University of Illinois 2005). Those lines came from argon excited states above 13 eV and from the O2+ ion, energies that heat alone at the measured temperatures could not supply, which pointed to collisions with energetic electrons and ions from a plasma core (Flannigan and Suslick, Nature 2005).
The gas recipe changes everything. Raising the noble gas content of a nitrogen bubble to about 1% stabilized the bubble and lifted light output by over an order of magnitude (Hiller, Weninger, Putterman and Barber, Science 1994). Theory later explained why air works: nitrogen and oxygen dissociate and react into water-soluble products, so a strongly driven air bubble ends up as nearly pure argon (Lohse et al., arXiv preprint of Physical Review Letters 1997).
| Metric | Value | Source |
|---|---|---|
| Energy of argon excited states seen in single-bubble spectra | above 13 eV | Flannigan and Suslick, Nature 2005 |
| Location of any spectral peak for a single bubble in water | above 6 eV photon energy | Hiller, Putterman and Barber, Physical Review Letters 1992 |
| Energy range of emitting noble-gas atom and ion states, Xe to Ar+ | 8.3 eV to 37.1 eV above ground state | Flannigan and Suslick, Physical Review Letters 2005 |
| Brightness gain of sulfuric acid over water | nearly 3,000 times | University of Illinois news release 2005 |
| Noble gas content in a nitrogen bubble that stabilizes motion | about 1%, with light emission up over an order of magnitude | Hiller et al., Science 1994 |
| Spectral peak of a xenon bubble vs a helium bubble | about 300 nanometers for xenon; helium peak hidden by the ultraviolet cutoff of water | Hiller et al., Science 1994 |
| Solution used for plasma diagnostics | 85 wt% H2SO4 with Ar at 5% of saturation | Flannigan and Suslick, Nature Physics 2010 |
| First Eu2+ ion bands seen in single-bubble light, nanoparticle suspensions | detected for the first time; nanoparticles below 50 nm, about 27 kHz | Gareev et al., Applied Spectroscopy 2024 |
Context: in sulfuric acid with alkali-metal salts, smooth elliptical bubble motion gave argon lines, while erratic motion with abrupt changes of direction at higher drive gave alkali-metal lines and less light (Flannigan and Suslick, Physical Review Letters 2007). Spectral content depends on how the bubble moves, not only on what it contains.
6. Multi-Bubble vs Single-Bubble Sonoluminescence
Clouds of collapsing bubbles, not single trapped ones, are what industrial ultrasonic equipment produces, the same machines behind our industrial ultrasonic noise exposure statistics. Multi-bubble sonoluminescence (MBSL) in silicone oil gave an effective temperature of 5075 +/- 156 K (Flint and Suslick, Science 1991), about one third of the 15,000 K single-bubble ceiling in section 1 (5,075 / 15,000 = 0.34).
The cloud value is also adjustable. By changing the polytropic ratio of the gas mixture (how strongly the gas heats when compressed) and the solvent vapor pressure, the same group moved the MBSL emission temperature from 5,100 to 2,300 K (McNamara, Didenko and Suslick, Nature 1999). A single bubble wins on light per joule: its energy efficiency for forming hydroxyl radicals is comparable to a cloud’s, but its light emission efficiency is much higher (Didenko and Suslick, Nature 2002).
| Metric | Value | Source |
|---|---|---|
| Effective MBSL temperature from C2 Swan band emission in silicone oil | 5075 +/- 156 K | Flint and Suslick, Science 1991 |
| Range of MBSL emission temperature achieved by varying gas and solvent | 5,100 to 2,300 K | McNamara, Didenko and Suslick, Nature 1999 |
| Energy of an emitted photon vs the energy density of the sound field | can exceed it by about twelve orders of magnitude | McNamara, Didenko and Suslick, Nature 1999 |
| Earlier MBSL temperature estimates vs single-bubble argon-line temperatures | around 5,000 K vs 15,000 K by 2.9 bar | Physics Today 2005 |
| Energy efficiency of single-bubble vs multi-bubble cavitation | OH radical formation comparable; light emission much higher for one bubble | Didenko and Suslick, Nature 2002 |
| Change in MBSL light output across noble gases | rises from He to Xe | Didenko, McNamara and Suslick, Physical Review Letters 2000 |
| Simulated peak temperature range in dual-frequency cavitation, 2 μm initial radius | approximately 3000-10190 K | Lv, Zheng, Cui et al., Ultrasonics Sonochemistry 2026 |
Context: MBSL is the regime that drives sonochemistry, while SBSL is the repeatable version used to test theory. The 2026 dual-frequency figures are simulation outputs for a single model bubble, not measurements of a cloud.
7. The Bubble Fusion Claims: What the Primary Record Shows
Extreme temperatures invited an obvious question. In 2002 a Science paper reported tritium and neutron emission near 2.5 million electron volts from cavitation in deuterated acetone, and simulations implying 10⁶ to 10⁷ kelvin (Taleyarkhan et al., Science 2002). Control runs with normal acetone showed neither tritium nor neutrons, according to the same paper.
A repeat with the same cavitation apparatus and a larger scintillator found no 2.5-MeV neutrons correlated with sonoluminescence, and put any such emission at least 4 orders of magnitude too low to explain the reported tritium (Shapira and Saltmarsh, Physical Review Letters 2002). The SBSL plasma measurements in sections 1 and 2 reach about 10²¹ electrons per cubic centimeter, against the roughly 10²⁴ that inertial confinement fusion aims for (APS Physics 2014).
| Metric | Value | Source |
|---|---|---|
| Neutron energy reported from cavitation in deuterated acetone | near 2.5 million electron volts | Taleyarkhan et al., Science 2002 |
| Bubble temperatures implied by the authors’ shock simulations | 10⁶ to 10⁷ kelvin | Taleyarkhan et al., Science 2002 |
| Shortfall of any correlated neutron emission vs reported tritium, in a repeat experiment | at least 4 orders of magnitude too small | Shapira and Saltmarsh, Physical Review Letters 2002 |
| Verdict of a 2002 comment by three sonoluminescence researchers | data neither proves nor disproves fusion | Putterman, Crum and Suslick, arXiv 2002 |
| Misconduct allegations upheld by a Purdue committee, out of those considered | 2 of 12 | Physics Today 2008 |
| Sanction on graduate supervision | cannot serve as a major professor for at least three years | Physics Today 2008 |
| Electron density in SBSL vs target density for inertial confinement fusion | 10²¹ vs about 10²⁴ electrons per cubic centimeter | APS Physics 2014 |
Context: the Purdue findings concerned a 2006 Physical Review Letters paper that called the 2002 results independently confirmed and the addition of a coauthor to a 2005 Nuclear Engineering and Design paper (Physics Today 2008). In 2010 Suslick stated his group had not observed evidence that fusion takes place during sonoluminescence (Grainger College of Engineering, University of Illinois 2010).
Summary: Single-Bubble Sonoluminescence by the Numbers
| Metric | Value | Source |
|---|---|---|
| Argon emission temperature, single bubble in sulfuric acid | 4,000-15,000 K | Flannigan and Suslick, Nature 2005 |
| Peak optical power of one bubble in water | over 30 mW | Hiller, Putterman and Barber, Physical Review Letters 1992 |
| Upper end of intracavity temperatures | up to 20,000 K | Suslick and Flannigan, Annual Review of Physical Chemistry 2008 |
| Electron density | can exceed 10²¹ cm⁻³ | Flannigan and Suslick, Nature Physics 2010 |
| Number density from laser probing | 2×10²¹ cm⁻³ | Bataller et al., Physical Review Letters 2014 |
| Lower limit of collapse pressure | 5500 bars | Holzfuss, Rüggeberg and Billo, Physical Review Letters 1998 |
| Plasma opacity vs Saha equation | can be 1000 times more opaque | Khalid et al., Physical Review Letters 2012 |
| Flash width, air bubble in water | about 60 ps to more than 250 ps | Gompf et al., Physical Review Letters 1997 |
| Flash width, various gas mixtures | under 40 to over 350 ps | Hiller, Putterman and Weninger, Physical Review Letters 1998 |
| Photons per pulse at 7.1 kHz | 10^4-10^5 | Toegel et al., Physical Review Letters 2000 |
| Bubble wall collapse speed | faster than Mach 4 | Weninger, Barber and Putterman, Physical Review Letters 1997 |
| Stable driving pressure window | about 1.2-1.5 atm | Hilgenfeldt, Lohse and Brenner, Physics of Fluids 1996 |
| First stable single bubble drive | about 150 kPa (1.5 atm) at 21-25 kHz | Gaitan et al., JASA 1992 |
| Ambient vs minimum radius, 2025 simulation | 4.5 μm vs 0.747744 μm | Wang and Liang, Ultrasonics Sonochemistry 2025 |
| Energy density concentration | 12 orders of magnitude | Krimans, Ruuth and Putterman, Physical Review E 2025 |
| Light gain from about 1% noble gas in nitrogen | over an order of magnitude | Hiller et al., Science 1994 |
| Brightness gain in sulfuric acid vs water | nearly 3,000 times | University of Illinois 2005 |
| Multi-bubble temperature in silicone oil | 5075 +/- 156 K | Flint and Suslick, Science 1991 |
| Neutron shortfall in bubble fusion repeat | at least 4 orders of magnitude | Shapira and Saltmarsh, Physical Review Letters 2002 |
Methodology and Sources
We read abstracts, figure captions and publisher records through the journals, arXiv, PubMed Central, Europe PMC and OpenAlex, and kept only numbers stated in those records. Uncertainties and notation (for example “5075 +/- 156 K”, “≳20 eV”, “P_a ~ 1.2-1.5 atm”) are reproduced as published.
- Flannigan and Suslick, Plasma formation and temperature measurement during single-bubble cavitation, Nature 434, 52-55 (2005)
- Flannigan and Suslick, Inertially confined plasma in an imploding bubble, Nature Physics 6, 598-601 (2010)
- Suslick and Flannigan, Inside a collapsing bubble, Annual Review of Physical Chemistry 59 (2008)
- Brenner, Hilgenfeldt and Lohse, Single-bubble sonoluminescence, Reviews of Modern Physics 74, 425-484 (2002), University of Twente record
- Gompf, Günther, Nick, Pecha and Eisenmenger, Physical Review Letters 79, 1405 (1997)
- Hiller, Putterman and Weninger, Time-resolved spectra of sonoluminescence, Physical Review Letters 80, 1090 (1998)
- Toegel, Gompf, Pecha and Lohse, Does water vapor prevent upscaling sonoluminescence?, Physical Review Letters 85, 3165 (2000)
- Holzfuss, Rüggeberg and Billo, Shock wave emissions of a sonoluminescing bubble, arXiv chao-dyn/9811022 (Physical Review Letters 81, 5434, 1998)
- Hilgenfeldt, Lohse and Brenner, Phase diagrams for sonoluminescing bubbles, arXiv chao-dyn/9608005 (Physics of Fluids 8, 2808, 1996)
- Lohse, Brenner, Dupont, Hilgenfeldt and Johnston, Sonoluminescing air bubbles rectify argon, arXiv chao-dyn/9605003 (Physical Review Letters 78, 1359, 1997)
- Hiller, Weninger, Putterman and Barber, Effect of noble gas doping in single-bubble sonoluminescence, Science 266, 248 (1994)
- Flannigan and Suslick, Plasma line emission during single-bubble cavitation, Physical Review Letters 95, 044301 (2005); Emission from electronically excited metal atoms, Physical Review Letters 99, 134301 (2007)
- Gaitan et al., Sonoluminescence and bubble dynamics for a single, stable, cavitation bubble, JASA 91, 3166 (1992)
- Hiller, Putterman and Barber, Physical Review Letters 69, 1182 (1992); Barber and Putterman, Physical Review Letters 69, 3839 (1992); Weninger, Barber and Putterman, Physical Review Letters 78, 1799 (1997); Camara, Putterman and Kirilov, Physical Review Letters 92, 124301 (2004); Kappus, Khalid, Chakravarty and Putterman, Physical Review Letters 106, 234302 (2011); Khalid, Kappus, Weninger and Putterman, Physical Review Letters 108, 104302 (2012); Bataller, Kappus, Camara and Putterman, Physical Review Letters 113, 024301 (2014), summarized in APS Physics 7, 72 (2014)
- Didenko and Suslick, The energy efficiency of formation of photons, radicals and ions during single-bubble cavitation, Nature 418, 394 (2002)
- Flint and Suslick, The temperature of cavitation, Science 253, 1397 (1991); McNamara, Didenko and Suslick, Nature 401, 772 (1999); Didenko, McNamara and Suslick, Physical Review Letters 84, 777 (2000)
- Wang and Liang, Single-bubble sonoluminescence at two adjacent antinodes, Ultrasonics Sonochemistry 123, 107662 (2025)
- Shen, Pflieger, Chen et al., The effect of bulk viscosity on single bubble dynamics and sonoluminescence, Ultrasonics Sonochemistry 93, 106307 (2023)
- Lv, Zheng, Cui et al., dual-frequency acoustic cavitation, Ultrasonics Sonochemistry 132, 107964 (2026)
- Krimans, Ruuth and Putterman, high Mach number bubble collapse, arXiv 2410.05244 (Physical Review E 112, 065107, 2025)
- Gareev et al., Single-bubble sonoluminescence of colloidal suspensions of europium(II) salt nanoparticles, Applied Spectroscopy 78 (2024)
- Taleyarkhan et al., Evidence for nuclear emissions during acoustic cavitation, Science 295 (2002); Shapira and Saltmarsh, Physical Review Letters 89, 104302 (2002); Putterman, Crum and Suslick, arXiv cond-mat/0204065
- Physics Today, Bubble fusion scientist disciplined (2008); Physics Today, Evidence for a plasma inside a sonoluminescing bubble (2005)
- University of Illinois news releases: Bubbling hot (2005) and Pop goes the plasma (2010)
- Data watch: most measured values are older than three years and should be read as most recent available data (1991 to 2014); the peak temperature, peak pressure and radius figures from the 2023, 2025 and 2026 Ultrasonics Sonochemistry papers are simulation outputs, not measurements (the 2025 antinode pressures and flash widths are measured). The 2005 Illinois release says about 20,000 K while the Nature abstract gives 4,000-15,000 K; we headline the abstract. APS Physics describes the 2012 UCLA experiment as using 100-micrometer bubbles in phosphoric acid, while the PRL abstract describes a 70 μm radius plasma; we cite neither as a bubble radius. The Wang and Liang 2025 paper prints the simulated bubble 2 radiated power as 1.0392×10⁵ W in Results and 1.0392×10⁻⁵ W in Discussion, so we left that value out. We found no retraction notice for the 2002 Science bubble fusion paper; the 2008 Purdue findings concerned later papers.
Last updated: October 25, 2026. We update this roundup quarterly, and the next refresh is expected when Ultrasonics Sonochemistry publishes its next single-bubble sonoluminescence measurements in its January 2027 volume.