Temperature distribution along a metal filament heated in vacuum by DC current

Hałas, Stanisław; Durakiewicz, Tomasz

doi:10.1016/s0042-207x(97)00170-x

Cited by 19 publications

(14 citation statements)

References 5 publications

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“…For these thin tungsten filaments the temperature gradients along the hot wire could be neglected and energy power losses are mainly caused by radiation emission. Therefore, the temperatures were determined using a well known expression relating the DC heating current along the wire with T , which is regarded essentially uniform [21][22][23].…”

Section: Methodsmentioning

confidence: 99%

Non-equilibrium thermionic electron emission for metals at high temperatures

Domenech-Garret

Tierno

Conde

2015

Journal of Applied Physics

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The stationary thermionic electron emission currents from heated metals are compared against an analytical expression derived using a non equilibrium quantum Kappa energy distribution for the electrons. This later depends on the temperature decreasing parameter κ(T ) which can be estimated from the raw experimental data and characterizes the departure of the electron energy spectrum from the equilibrium Fermi-Dirac statistics. The calculations accurately predict the measured thermionic emission currents for both high and moderate temperature ranges. The Richardson-Dushman law governs the electron emission for large values of Kappa or equivalently, for moderate metal temperatures. The high energy tail in the electron energy distribution function which develops at higher temperatures or lower Kappa parameters, increases the emission currents well over the predictions of the classical expression. This analysis also permits the quantitative estimation of the departure of the metal electrons from the equilibrium Fermi-Dirac statistics.

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Section: Methodsmentioning

confidence: 99%

Non-equilibrium thermionic electron emission for metals at high temperatures

Domenech-Garret

Tierno

Conde

2015

Journal of Applied Physics

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“…In another publication, 4 we considered a short filament fed a constant current I. The temperature distribution along the filament has to be calculated first by numerical solving of the following equation:…”

Section: Dependence Of ®Lament Temperature On Voltagementioning

confidence: 99%

Temperature controller for thermal ionization mass spectrometry

Hałas

Wojtowicz

Nowak

et al. 2001

Rapid Comm Mass Spectrometry

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We describe the use of a simple voltage stabilizer that controls the filament temperature (T(f)) in the ion source of a thermal ionization mass spectrometer. The filament voltage (V(f)) is measured by means of a separate pair of wires connected inside of the ion source in parallel to the wires supplying power. It has been demonstrated that V(f) is directly proportional to T(f) in a wide range of filament temperature. The T(f) value is solely controlled by the reference voltage (V(r)) that can be manually selected from a voltage divider or by means of a computer. Digital signals from the computer in the form of a series of pulses are transmitted opto-electronically and subsequently converted to analog signals. The temperature controller described here was successfully applied for analysis of potassium concentration by the isotope dilution method.

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“…Some analytic methods have been presented in [2], but only for the part near the centre of the filament and with a large error. More accurate calculations have been done in [3], but without calculations of the electron emission current. Furthermore, all those methods need to know (e.g.…”

Section: Introductionmentioning

confidence: 99%

“…The LabView environment has possibilities of designing a relatively fast graphical user interface and creating independent applications; therefore, it has been evaluated as an adequate environment. An algorithm was used which is a modification of the one from studies [3,6] in a way which allows to calculate the temperature and thermionic emission current distribution without measurements of the filament leads temperature. It is also able to calculate the cumulative thermionic emission current.…”

Section: Introductionmentioning

confidence: 99%

A LabView‐based hot cathode electron source simulator with no‐boundary condition computation method

Kania

2016

Int J Numerical Modelling

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Fast and complex model-based computations are often needed during the controller design process; therefore, a hot cathode electron source simulator was designed and implemented. The simulator uses the static model of electron source and is based on the LabView environment. It is developed for different materials and dimensions of filaments popular in vacuum instruments. The simulator is able to calculate the maximum temperature of the hot filament, its resistance, voltage drop and temperature and distribution of the electron emission current along the filament length in a steady state. Also, a new method was proposed and implemented for approximate calculations of distributions of the temperature and the electron emission current without measurements of the filament temperature.

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Temperature distribution along a metal filament heated in vacuum by DC current

Cited by 19 publications

References 5 publications

Non-equilibrium thermionic electron emission for metals at high temperatures

Non-equilibrium thermionic electron emission for metals at high temperatures

Temperature controller for thermal ionization mass spectrometry

A LabView‐based hot cathode electron source simulator with no‐boundary condition computation method

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