What really happens with the electron gas in the famous Franck‐Hertz experiment?

Sigeneger, F.; Winkler, R.; Robson, Robert

doi:10.1002/ctpp.200310014

Cited by 29 publications

(27 citation statements)

References 26 publications

(60 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During the pre-breakdown phase an oscillation of the wave front potential and E field is observed. This ripple cannot be related to fluctuations in the applied unipolar voltage waveform, and the fact that the period of this oscillations decreases at higher V A values point toward a Frank and Hertz effect [44]. An increase of the E field strength of the pre-breakdown wave front occurs at the end of its propagation.…”

Section: Electric Field and Potential Evolutionsmentioning

confidence: 92%

Optical and electrostatic potential investigations of electrical breakdown phenomena in a low-pressure gas discharge lamp

Gendre¹,

Haverlag²,

Kroesen³

2010

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

The ignition phase is a critical stage in the operation of gas discharge lamps where the neutral gas enclosed between the electrodes undergoes a transformation from the dielectric state to a conducting phase, eventually enabling the production of light. The phenomena occurring during this phase transition are not fully understood and the related experimental studies are often limited to local optical measurements in environments prone to influencing these transient phenomena. In this work unipolar ignition phenomena at sub-kilovolt levels are investigated in a 3 Torr argon discharge tube. The lamp is placed in a highly controlled environment so as to prevent any bias on the measurements. A fast intensified CCD camera and a specially-designed novel electrostatic probe are used simultaneously so as to provide with a broad array of measured and computed parameters which are displayed in space-time diagrams for cross comparisons. Experiments show that three distinct phases exist during successful ignitions: Upon the application of voltage a first ionization wave starts from the active electrode and propagates in the neutral gas toward the opposite electrode. A local front of high axial E field strength is associated with this process and causes a local ionisation to occur, leading to the electrostatic charging of the lamp. Next, a second wave propagates from the ground electrode back toward the active electrode with a higher velocity, and in this process leads to a partial discharging of the lamp. This return stroke draws a homogeneous plasma column which eventually bridges both electrodes at the end of the wave propagation. At this point both electrode sheaths are formed and the common features of a glow discharge are observed. The third phase is an increase of the light intensity of the plasma column until the lamp reaches a steady state operation. Failed ignitions present only the first phase where the first wave starts its propagation but extinguishes in the lamp, leading to a charge memory effect. It is found that the full propagation of this first wave is a requirement for a successful lamp ignition. Differences in the properties of the waves were observed depending on the voltage polarity, and it was estimated that a photoelectric effect at the wall is the most likely source of electron for the ionisation wave of positive polarity. Finally a simple model of the first ionization wave is developed and used to analyse the fundamental differences between processes occurring at negative and at positive polarity. From this study three conditions are developed for the successful unipolar ignition of lamps and the relations between them are derived.

show abstract

Section: Electric Field and Potential Evolutionsmentioning

confidence: 92%

Optical and electrostatic potential investigations of electrical breakdown phenomena in a low-pressure gas discharge lamp

Gendre¹,

Haverlag²,

Kroesen³

2010

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

show abstract

“…The electron kinetics of quite different problems could successfully be analysed extending from basic problems in model plasmas up to problems in real discharge arrangements. In particular, (i) the electron kinetics in the anode region of dc glow discharges [21], (ii) the behaviour of the electron gas in the spatial decay to the remote plasma region [22,23], (iii) the spatial kinetics of trapped electrons effected by the occurrence of a potential energy valley in the plasma [23], (iv) the response of the electron gas to the spatial field transition from accelerating to retarding electric fields occurring in grid-controlled arrangements [24], (v) the spatiotemporal transition and propagation processes of the electron gas in the column-anode region of a glow discharge [25], and (vi) the additional impact of electron-electron collisions on the spatial [26,27] and spatiotemporal [28] relaxation of plasma electrons have been investigated.…”

Section: Kinetics Of the Electronsmentioning

confidence: 99%

Electron Kinetics and Self‐Consistent Description of Inhomogeneous and Nonstationary Plasmas

Loffhagen¹,

Arndt²,

Sigeneger³

et al. 2005

Contrib. Plasma Phys.

Self Cite

View full text Add to dashboard Cite

A brief introduction into the progress of the analysis of the electron kinetics and the self-consistent description of inhomogeneous and nonstationary plasmas is given. The spectrum of problems treated by electron kinetic studies as well as by the overall description of non-isothermal plasmas is briefly characterized. Main aspects of the analyses are outlined and the progress reached in recent years in the framework of the collaborative research activities of the Sonderforschungsbereich 198 "Kinetics of partially ionized plasmas" is illustrated by topical kinetic study and self-consistent modelling results of some selected problems.

show abstract

“…The cross section set for mercury is the same as that used in Ref. [12]. For barium, the ionization cross section was taken from Ref.…”

Section: Electron Kineticsmentioning

confidence: 99%

Barium transport in the hot spot region of fluorescent lamps

Sigeneger¹,

Rackow²,

Uhrlandt³

et al. 2010

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

Abstract. The transport of barium atoms and ions in the vicinity of the hot spot in fluorescent lamps operating at 25 kHz is investigated by a combined experimental and theoretical approach. By laserinduced fluorescence, the particle densities of barium atoms and ions were measured timeresolved at different distances from the spot center. In addition, the time-dependent cathode fall voltage was measured using an improved band method. The model combines a kinetic part for the electrons with a fluid part for the barium atoms and ions. Both parts are spatially resolved in spherically symmetric geometry. The space-dependent electron Boltzmann equation yields the electron density and the ionization rate coefficient of barium as functions of the cathode fall voltage. These results are used to solve the time-dependent particle balance equations of barium atoms and ions which include the ionization of barium as gain and loss terms, respectively. Good agreement between the measured and calculated particle densities of barium atoms is obtained. A sensitive dependence of the ionization frequency and of the barium particle densities on the cathode fall voltage was found.

show abstract

What really happens with the electron gas in the famous Franck‐Hertz experiment?

Cited by 29 publications

References 26 publications

Optical and electrostatic potential investigations of electrical breakdown phenomena in a low-pressure gas discharge lamp

Optical and electrostatic potential investigations of electrical breakdown phenomena in a low-pressure gas discharge lamp

Electron Kinetics and Self‐Consistent Description of Inhomogeneous and Nonstationary Plasmas

Barium transport in the hot spot region of fluorescent lamps

Contact Info

Product

Resources

About