The emission of electrons and positive ions from fracture of materials

Dickinson, J. T.; Donaldson, E. E.; Park, M. K.

doi:10.1007/bf00552976

Cited by 38 publications

(42 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Another possibility is that particle‐particle contacts in the fountain result in spallation at very small scales—i.e., our experiments may also incorporate fragmentation processes. While many studies suggest that both positive and negative ions and electrons are emitted during fracture (implying that such process does not bias the polarity of the parent material) [ Dickinson et al ., ; Enomoto and Chaudhri , ], James et al . [] inferred that positive ions were emitted in higher numbers during the fracture of pumice samples, leaving fragments with overall negative charge.…”

Section: Resultsmentioning

confidence: 99%

“…For example, size‐dependent bipolar charging (i.e., where large particles charge positively and small grains charge negatively, on average) appears to be a rather universal characteristic of triboelectric charging [ Lacks and Levandovsky , ; Forward et al ., ; Lacks and Sankaran , ; Bilici et al ., ]. Such size dependence, however, is not present in the fracture mechanism (i.e., a small particle is just as likely to charge positively or negatively, and vice versa [ Dickinson et al ., ; James et al ., ]). Furthermore, there is evidence that small‐scale processes can importantly tune large‐scale electrostatic phenomena.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The effects of dynamics on the triboelectrification of volcanic ash

Harper

Dufek

2016

JGR Atmospheres

View full text Add to dashboard Cite

Lightning is often observed during explosive volcanic eruptions, and the charging processes associated with these displays have been attributed to several mechanisms. In this work we delineate a set of experiments designed to quantify silicate-based triboelectric charging in the volcanic context. Using natural samples from three different volcanoes, we show that the rate of triboelectrification in a fluidized bed depends on the energy input into the granular system. Experiments are conducted employing nonintrusive electrostatic sensors, ensuring that all charge exchange arises solely from particle-particle collisions. At higher fluidization energies, particles undergo more frequent and energetic collisions, facilitating the transfer of charge. This finding implies that triboelectric charging could help promote charging in regions of the eruptive system that contain numerous particle-particle collisions such as the conduit and gas thrust regions. Our experiments also suggest that surface charge density is capped, at least in part, by atmospheric conditions, specifically the breakdown characteristics of the gas.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The effects of dynamics on the triboelectrification of volcanic ash

Harper

Dufek

2016

JGR Atmospheres

View full text Add to dashboard Cite

show abstract

“…Over the past 10-20 years there has been continuing interest in electromagnetic radiation associated with fracture of materials in the field of materials science and from the study of "earthquake lights" (light emission at the earth's surface associated with earthquakes). Emission of electrons, positive ions, and photons from rock undergoing fracture have been reported by Brady and Rowell (1986), Cress et al (1987), Dickinson et al (1981), Enomoto and Hashimoto (1990), and Khatiashvili and Perel'man (1989) among others. Most of these authors suggest, as Adushkin et al (1995) do, that as a fracture develops and advances, there is a charge separation on each face of the fracture.…”

Section: Introductionmentioning

confidence: 83%

Low-frequency electromagnetic measurements as a zero-time discriminant of nuclear and chemical explosions -- OSI research final report

Sweeney¹

1996

View full text Add to dashboard Cite

This is the final report on a series of investigations of low frequency (1-40 Hz) electromagnetic signals produced by above ground and underground chemical explosions and their use for confidence building under the Comprehensive Test-Ban Treaty. I conclude that low frequency electromagnetic measurements can be a very powerful tool for zero-time discrimination of chemical and nuclear explosions for yields of 1 Kt or greater, provided that sensors can be placed within 1-2 km of the suspected detonation point in a tamper-proof, low noise environment. The report includes descriptions and analyses of low frequency electromagnetic measurements associated with chemical explosions carried out in a variety of settings (shallow borehole, open pit mining, underground mining). I examine cavity pressure data from the Non-Proliferation Experiment (underground chemical explosion) and present the hypothesis that electromagnetic signals produced by underground chemical explosions could be produced during rock fracturing. I also review low frequency electromagnetic data from underground nuclear explosions acquired by Lawrence Livermore National Laboratory during the late 1980s.2 Nevada Test Site (NTS). The report by Sweeney (1995) gives the details of the mine measurements and preliminary results from the Kuchen experiment. Experience at Henderson Mine revealed difficulties involved with surface measurements of events occurring deep underground in a noisy mine environment. The Carlin experience indicated that the EM signal from a ripple-fired surface explosion is smaller than what would be expected from a single explosion equivalent in size to the total ripple-fired yield. Preliminary results of the Kuchen experiment indicated that the arming and firing circuitry can produce low frequency EM signals detectable at the surface near the borehole.In this report, all the results of the Kuchen experiment are discussed along with results of two additional experiments carried out during FY96: measurements of several underground chemical explosions at the Linchburg experiment site in New Mexico and measurements done during a hydrofracturing experiment at the Lost Hills oil field in the southern San Joaquin Valley, California. The final section of this report contains a summary of our current understanding of the phenomena of low frequency EM generated by chemical and nuclear explosions.

show abstract

“…The experimental part of this study was conducted by using a unique high vacuum in-house built tribometer [12,13,29], schematically represented in Fig. 1.…”

Section: Experimental Methodsmentioning

confidence: 99%

“…In particular, in lubricated contacts in the formation of boundary films and in certain cases in their degradation tribocharging and a phenomenon known collectively as triboemission they have been suggested as playing a key role. Triboemission consists of emission of charged particles such as electrons, protons, positive and negative ions and also acoustic emission that occur when hard, solid surfaces are rubbed together [10][11][12][13][14][15][16][17]. If a lubricant is present, these particles may promote chemical reactions that lead to both degradation [18], and formation of protective films on the surface of components [19].…”

Section: Introductionmentioning

confidence: 99%

A Combined Experimental and Theoretical Study on the Mechanisms Behind Tribocharging Phenomenon and the Influence of Triboemission

et al. 2019

View full text Add to dashboard Cite

This work describes recent research into the mechanisms behind tribocharging and the influence of triboemission. The term tribocharging is a type of contact-induced electrification and refers to the transfer of charge between rubbing components. The term triboemission, on the other hand, refers to emission of electrons, ions and photons generated when surfaces are rubbed together. The understanding of tribocharging is of wide interest for several industrial applications and in particular the combination of tribocharging and triboemission may be important in lubricated contacts in the formation of boundary lubricant films. We report the use of a unique vacuum measurement system that enables to measure surface charge variations while simultaneously recording triboemission events during the sliding of a diamond tip on silica specimens. Results show for the first time that tribocharging and triboemission behavior are linked and depend on the surface wear. The contribution of contact-induced electrification to the charging of the surface is then described by means of density functional theory (DFT). Results give insight into the transfer of charge from the SiO 2 amorphous surface (silica) to the C(111) surface (diamond) and into the variation of charging during simulated sliding contact.

show abstract

The emission of electrons and positive ions from fracture of materials

Cited by 38 publications

References 21 publications

The effects of dynamics on the triboelectrification of volcanic ash

The effects of dynamics on the triboelectrification of volcanic ash

Low-frequency electromagnetic measurements as a zero-time discriminant of nuclear and chemical explosions -- OSI research final report

A Combined Experimental and Theoretical Study on the Mechanisms Behind Tribocharging Phenomenon and the Influence of Triboemission

Contact Info

Product

Resources

About