Electron-Temperature Dependence of Electron-Ion Recombination in Argon

Mehr, F. J.; Biondi, Manfred A.

doi:10.1103/physrev.176.322

Cited by 135 publications

(64 citation statements)

References 14 publications

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“…We also detect several Ni lines at 2 15-235 nm, which appear as a result of explosion of cathode spots manifold. This explosion has a delay of several nanoseconds from the pumping pulse maximum and takes place just after the local breakdown of the cathode sheath [14]. The brightness ofcontinuum emission increases strongly after cathode spots explosion and at later stages its emission is concentrated near specific cathode spots.…”

Section: Discharge Homogeneity and Spatial-resolved Uv-vis Spectramentioning

confidence: 99%

<title>Kinetics of VUV-VIS spontaneous emission of high-current pulsed volume discharge in argon</title>

Lissovski

Treshchalov

2006

SPIE Proceedings

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Spatial-time behavior of the main excited atomic and molecular excimer species were monitored with ns-gated ICCD camera (200-850 nm) and solar-blind PMT (1 15-300 nm) from spontaneous emission spectra ofhomogeneous volume discharge in high-pressure (up to 0 bar) argon. It is revealed, that broad (200-700 nm) UV-VIS continuum is caused mainly by radiative recombination of free plasma electrons with Ar2 ions. Emission intensities from this continuum and red Ar lines have a typical recombination behavior in the afterglow stage of the discharge (square root of its intensity is proportional to the electron density). Observed UV-VIS continuum spectrum is modeling by free-bound photorecombination transitions to manifold of4s, 4s , 4p, 4p , 3d, 3d Ar* levels. Peak intensity ofthe second continuum vUv emission from Ar2 excimers (126 nm) increases approximately quadratically with the gas pressure. This behavior is observed at pressure range of 1-2 bar, however at higher pressures the peak intensity has a tendency to the saturation. vUv emission from Ar2* '(O) molecules increases during small-power secondary pumping pulses due to better mixing of singlet and triplet Ar2* states by additional electrons.

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Section: Discharge Homogeneity and Spatial-resolved Uv-vis Spectramentioning

confidence: 99%

<title>Kinetics of VUV-VIS spontaneous emission of high-current pulsed volume discharge in argon</title>

Lissovski

Treshchalov

2006

SPIE Proceedings

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“…As one can see in figure 7, the gas temperature has a significant influence on the lifetime of the afterglow, higher gas temperatures lead to a slower decay. This is mainly due to the 1 − g T dependency of the rate coefficient for the formation of molecular ions [34], since a slower formation of these leads to a decreased recombination rate. For the comparison of the effect of the superelastic collisions, Penning-ionization and excimer processes on the lifetime of the afterglow, the simulation was also run with only one and none these reaction types activated.…”

Section: The Early Afterglowmentioning

confidence: 99%

Investigations on the afterglow of a thin cathode discharge in argon at atmospheric pressure

Mohr¹,

Du²,

Luggenhölscher³

et al. 2010

J. Phys. D: Appl. Phys.

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Abstract.A thin cathode discharge consists of two electrodes separated by a dielectric layer with a thickness of ca. 100 µm. The shape of the anode can be chosen arbitrarily, while the thickness of the cathode is also about 100 µm. Through this "sandwich", a hole with a diameter of 200 µm is drilled. When such a device is operated at pressures of several 100 hPa, it shows a self-pulsing behaviour in which high electron densities of several Electrical measurements showed, that this can be explained by the repeated ignition of a shortliving spark discharge. Due to the high pressure and the related high collision frequencies, the afterglow of this discharge was expected to last several 10 ns. Instead, lifetimes of several 100 ns were observed. In order to identify the mechanisms responsible for this long living afterglow, a kinetic model of the afterglow was developed. As a result, Penning-ionization, superelastic collisions with both atoms in excited states and excimers were found to play a crucial role in the production and heating of electrons.

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“…It is possible to account qualitatively for these strikingly different behaviors in terms of the details of the potential curve crossings between the molecular ion and the unstable molecule states and in terms of the changing vibrational state populatio~ls of the molecular ion with changing Ti (31). We point out the problem to demonstrate that present theoretical treatments of the dissociative recombination process are essentially in their infancy and to stress the critical importance of being able to specify the ions' electronic and vibrational states in laboratory measurements before the results can be applied with confidence to ionospheric calculations.…”

Section: B Dissociative Recombinatioizmentioning

confidence: 99%

“…It will be seen that a single power law temperature dependence, of the form T -' , is followed over the measured range. Very recently, Mehr and Biondi (18) have used a microwave afterglow/mass spectrometer apparatus with microwave electron heating to study ~( 0 , ' ) under conditions such that T, 2 Ti = 300 OK. For 0,' ions it is found that a = 1.95 x cm3/s at T, = 300 OK and decreases as T,-0.70 up to T, = 1200 OK and then decreases as T , -~.~~ up to T, = 5000 OK. In these studies excited electronic states of 0,' may be present (0,-Ne mixtures were used); thus the data should be compared with the inverted triangles shown in Fig.…”

Section: B Dissociative Recombinatioizmentioning

confidence: 99%

Atmospheric electron–ion and ion–ion recombination processes

Biondi¹

1969

Can. J. Chem.

Self Cite

161

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The electron-ion and ion-ion recombination processes of importance in the upper atmosphere are considered, and available laboratory experimental and theoretical information concerning the relevant processes is discussed. For atomic ions the principal electron-ion recombination process is radiative, with theory indicating that the two-body coefficient at -200 "K is -10-" cm3/s and decreases with increasing electron temperature. Microwave afterglow/mass spectrometer studies of diatomic ionospheric ions (e.g. NOf, 02f., and N Z f ) show a loss by dissociative recombination with a coefficient substantially in excess of cm3/s at 250 "K and decreasing with increasing electron and ion temperature. There is some evidence from flame studies that H 3 0 f ions exhibit a very large coefficient (10-6-10-5 cm3!s) at 300 OK. Ion-ion recombination evidently proceeds by mutual neutralization, with laboratory studies of ions such as NOf and NO2-indicating a two-body coefficient of the order of cm3/s at 300 OK. In the lower D region, three-body Thomson recombination may be important, since laboratory studies of "air" ions indicate a three-body coefficient of -2 x cm6/s at 300 OK.

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Electron-Temperature Dependence of Electron-Ion Recombination in Argon

Cited by 135 publications

References 14 publications

<title>Kinetics of VUV-VIS spontaneous emission of high-current pulsed volume discharge in argon</title>

<title>Kinetics of VUV-VIS spontaneous emission of high-current pulsed volume discharge in argon</title>

Investigations on the afterglow of a thin cathode discharge in argon at atmospheric pressure

Atmospheric electron–ion and ion–ion recombination processes

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