Fast and efficient plasma heating through superelastic laser energy conversion

Measures, Raymond M.; Wizinowich, Peter; Cardinal, P. G.

doi:10.1063/1.328142

Cited by 11 publications

(5 citation statements)

References 13 publications

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“…We assume that the electron concentration and temperature do not change significantly due to the laser excitation. As stated by Measures et al [19], the collisional transfer of energy from the excited atoms to plasma at a number density of about 10 12 cm −3 is negligible.…”

Section: Discussionmentioning

confidence: 80%

“…The upper limit of the concentration range where this method can be applied reaches about 10 14 cm −3 . For higher densities the results might be strongly affected by disturbing collisional processes (such as energy pooling collisions [14], mixing of population of excited atoms by electron impact [13] or heating of electrons by the laser pulse [19]), which were neglected in our approach.…”

Section: Resultsmentioning

confidence: 99%

“…We neglect the electron impact depopulation of the 4p level, since for the electron density that might occur in our cell (N e < 10 11 cm −3 ) the rate for this process k D 4p N e < 10 4 s −1 , i.e it is much smaller than the spontaneous emission rate [15]. We do not take into account production of Na(4p) atoms due to secondary collisions of electrons with sodium atoms excited to other levels, since the rates for these mechanisms are of the same order as the depopulation rate [19]. Population of Na(4p) atoms due to excited atom impacts can be neglected as well, since this process is much less efficient than electronic collisions [14].…”

Section: Discussionmentioning

confidence: 99%

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Method for monitoring of excited atom populations

Pietruczuk¹,

Stacewicz²,

Wilska³

et al. 2005

Meas. Sci. Technol.

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We present a simple method for monitoring of resonantly excited atom populations. Registration of fluorescence from higher excited levels was used for this purpose. These levels are populated due to collisions of electrons with the atoms of interest. The method is especially useful in the range of high atomic number densities, where due to reabsorption the excited atom population cannot be obtained by observation of their resonance fluorescence.

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Section: Discussionmentioning

confidence: 80%

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Method for monitoring of excited atom populations

Pietruczuk¹,

Stacewicz²,

Wilska³

et al. 2005

Meas. Sci. Technol.

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“…The theoretical approach of laser ionization by resonant light for long laser pulses (hundreds of nanoseconds) was given by Measures et al [8] and Bobin and Zaibi [9]. While, the model of few nanoseconds exciting pulses is presented by Stacewicz and Topulos [10].…”

Section: −3mentioning

confidence: 99%

Computational Study of Resonantly Ionizing Rubidium Vapor by Nanosecond Laser Pulses

Mahmoud¹,

Gamal²

2012

JMP

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An investigation of the resonant interaction of the rubidium atoms with an intensity (10 kW·cm −2 ≤ I ≤ 2 MW·cm) and a wavelength close to that of the D 1 and D 2 transitions of the rubidium atom (5S 1/2 → 5P 3/2 or 5S 1/2 → 5P 1/2 , λ D1 = 780 nm, λ D2 = 795 nm), which has passes through rubidium vapor with density (10 11 -10 14 cm −3) been studied theoretically. The system of equations describing the processes of Collisional ionization and multiphoton ionization of rubidium vapour resonantly excited with nanosecond pulsed laser is solved. The dependence of the ion density on the laser intensity and the atomic density of rubidium are considered. The result of calculations revealed that, both quadratic ion density dependence on laser intensity and linear behaviour of the ion density versus rubidium density for 5S 1/2 → 5P 3/2 transition is due to photoioization process. In contrast, for 5S 1/2 → 5P 1/2 transition, the ion density dependence is nonlinear and indicates that the collisional processes play the major contribution in the total ionization. Also, the obtained results showed reasonable agreement with the experimentally measured values of the ion density dependence given by Bakhramov et al. In addition, the analysis of mutual competition between the different ionization processes considered for the ion yield as a function of both laser intensity and atoms density are also presented this work.

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“…Under saturation conditions, Measures [17] and Measures et al [18] have shown that, the redistribution of the population between the two laser coupled states occurs in a time approximately given by:…”

Section: The Theoretical Modelmentioning

confidence: 99%

Kinetics of Rb2+ and Rb+ formation in laser-excited rubidium vapor

Mahmoud

2008

Open Physics

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Abstract:We have studied the formation of the molecular ion Rb + 2 and the atomic ion Rb + . These are created in laser excited rubidium vapor at the first resonance, 5s-5p and 5p-nl transitions. A theoretical model is applied to this interaction to explain the time evolution and the laser-power dependence of the population density of Rb + and Rb + 2 . A set of rate equations which describe: the temporal variation of the population density of the excited states; the atomic ion density; and the electron density, were solved numerically under the experimental conditions of Barbier and Cheret [5]. In their experiment the Rb concentration was 1 × 10 13 cm −3 and the laser power was taken to be 50-500 mW at vapor temperature = 450 K. The results showed that the main processes for producing Rb + 2 are associative ionization and Hornbeck-Molnar ionization. The calculations have also showed that, the atomic ions Rb + are formed through the Penning Ionization (PI) and photoionization processes. Moreover, a reasonable agreement between the experimental results and our calculations for the ion currents of the Rb + and Rb + 2 is obtained. PACS (2008): 34.80. Dp, 34.50.Fa

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Fast and efficient plasma heating through superelastic laser energy conversion

Cited by 11 publications

References 13 publications

Method for monitoring of excited atom populations

Method for monitoring of excited atom populations

Computational Study of Resonantly Ionizing Rubidium Vapor by Nanosecond Laser Pulses

Kinetics of Rb2+ and Rb+ formation in laser-excited rubidium vapor

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