Anomalies in Ionization Coefficients and in Uniform Field Breakdown in Argon for Low Values of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mfrac><mml:mrow><mml:mi>E</mml:mi></mml:mrow><mml:mrow><mml:mi>p</mml:mi></mml:mrow></mml:mfrac></mml:math>

Golden, D. E.; Fisher, L. H.

doi:10.1103/physrev.123.1079

Cited by 36 publications

(15 citation statements)

References 17 publications

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“…4 at high pd, and they are com- Paschen curves at high pel in argon Observed 17 Ehrenkrantz, 14 Kachikas and Fisher 18 and Golden and Fisher. 19 It is observed that in argon the sparking voltage depended markedly on the gap distance, gas pressure, the material of the cathode, even at high pd, and on impurities in the gas. values reported by Golden and Fisher are most probably due to the presence in their gas of the electronegative impurities CO and CO 2 ; they also observed a remarkable conditioning effect.…”

Section: = Bpdmentioning

confidence: 97%

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Uniform-field sparking voltages of gases in crossed magnetic fields

Dargan¹,

Heylen

1968

Proc. Inst. Electr. Eng. UK

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SynopsisThe influence of a crossed magnetic field on sparking voltages in nitrogen, hydrogen, argon and ethane has been investigated theoretically and experimentally for a uniform-field gap distance between 0 3 and 1 -2cm at gas pressures from 0-5 to 700torr using a magnetic field of up to 7500Gs. It is found that the influence of the magnetic field is greatest at low pressures and can adequately be accounted, for by the equivalent-pressure concept. The magnetic field tilts the electron avalanche and its successors through an angle d, so that the discharge path is increased and the effective field is reduced, thus increasing the strength of the gases, particularly at low pressure. Using these concepts, formulas are derived which agree well with the experimental results. A new method is presented whereby the important electron-molecule collision frequency can be determined from the present sparking data; values so derived agree well with the few reported in the literature.

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Section: = Bpdmentioning

confidence: 97%

“…Thus =-(£) W (19) This is the equation of a straight line, from the slope of which the electron collision frequency v can be determined. shown in Fig.…”

Section: £ -) = ( P D) 2mentioning

confidence: 99%

Uniform-field sparking voltages of gases in crossed magnetic fields

Dargan¹,

Heylen

1968

Proc. Inst. Electr. Eng. UK

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“…These parallelisms have been obtained from high γ values emitted by the surface‐dominated cold plasma with the bombardment or photon absorption. However, both this study and the existing studies do not mention the relationship between the increasing of γ ph and the low applied voltages of the breakdown evolutions at the higher values of pd . Therefore, for the electron emission from the different semiconductor materials we conclude that the lower applied voltages of the breakdown with the significant enhancement of γ i levels are remarkably achieved by the surface–ion interactions depending on the value of ϕ .…”

Section: Resultsmentioning

confidence: 72%

“…This is reasonable as, during the energy conversions from the cathodes, the g values of an InP cathode significantly exceed the g values obtained from GaAs and Si cathodes. For the levels of either g i or g ph , the behavior of the g levels indicates that there are similar directions with [6,[14][15][16]54] for the semiconductor and metal cathodes in the breakdown evolution at the reduced or enhanced values of E/N. In particular, these studies indicated the g ph levels at the reduced values of E/N and the g i levels at the enhanced values of E/N.…”

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confidence: 74%

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Surface behavior based on ion-induced secondary electron emission from semi-insulating materials in breakdown evolution

Koç

Karaköse

Salamov

2013

Phys. Status Solidi A

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This study focuses on analyses of secondary electron emission (SEE) at semiconductor surfaces when the sufficient conditions of space–time distribution occur. Experimental measurements and calculations with the approach of Townsend coefficients, which include the evaluations of ionization coefficient (α) and SEE coefficient (γ) were performed in high‐ohmic InP, GaAs, and Si semiconductor cathodes with argon and air environments in a wide range of E/N (300–10 000 Td). The direct calculations of γ were carried out to determine the behavior of cold‐semiconductor cathode current in a wide range of microgaps (45–525 μm). Paschen curves are interpreted in the dependence of large pd range on breakdown voltage through γ and α/N. Ion‐induced secondary electrons exhibit the direct behaviors affecting the timescale of breakdown evolution in the vicinity of the Paschen minimum during the natural bombardment process with ions of semiconductor cathodes. Also, when α/N rapidly drops and the excitations of gas atoms densely occupy the gas volume, we determined that the photoelectric effect provides a growth for electron emission from semiconductor surfaces at the breakdown stage at the reduced values of E/N. At all pressures, the emission magnitudes of electrons liberated by semiconductor cathodes into vacuum are found as γInP > γGaAs > γSi in breakdown evolution.

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Townsend‐Koeffizient α für Alkoholdämpfe, Luft und Argon

1972

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Measurcments of the first Townsend coefficient for the vapoiirs of CH,OH, C,HBOH. C,H,OH(n), C,H,OH(iso) are desrribed. r h e experimental arrangement is tested by measiiring the known values of air and argon. IZei der Fullung von %&hlrohr.cn verwendc man oft Blkohol-Dampfe. Cbcr den Ionisicrungs-Koeffizienten x dieser Dampfe licgen bisher nur wenige Arbeiten vor. I m Zusammenhang mib ZBhlrohr-Fragen haben wir deshalb einige sigene Messungen durchgefuhrt. Untersueht weiden nachfolgend die ersten drei Alkohole: Methyl-, Athyl-, Propyl-Alkohol, letzterer in der n-und iso-Form. Zur Kontrolle wurtle auch trockene Hg-freie Luft und drgorb durchgemessen. Die Xessung erfolgt wie ublich zwischen Platten-Elektroden im variablcn Abstand x [ern], im homogenen Feld E [ V/cm 1, beim Qasdruck p [Torr]. Xavh der THoMsos-Thcorie 11 ] wkd im Gas dcr photoelektrische Primarstrom I, verstarkt gemlifi I = I, exp (ax), wobei % / p = f(E/p). Bei p -= constans sollte also das Diagramm log = f(x) mit E als l'aramettr ein Geradenbuschel ergeben mit dem Ursprung h i x = 0, I = I,. Experimentell wird dies nur teilweise erfullt . Abb. 1 zcigt fur Methylalkoltol bei p 7 1 'rorr einen Ausschnitt unwrcr Xessungen bis . z -= l , 5 em, I = A ; dev tatsiichliche MeBbereich ging bis x = 2,,5 em, I = 10 lo A. I'm ganzen I3eruich zeigen die Kurven, entsprechend der Theoric, kcine erkennbare Rbweichung von der Gcradlinigkeit . Das Gloiche gilt auch fur die andcrm Alkohol-Dlimpfe und fur Luft. l3ei Argon bestcht aber die Geradlinigkeit nur am Anfang ; spatcr wiichst dic, Stromstgrkc iibcrexponentiell. Die Tlieoric fordrrt fur das Kurvc~nbusvhrl uincn gemeinsamen Ursprung. Aber die gemeinsamc. Anfangs-Ordinate I =-I, cxistiert nur annahernd wegen der Ruckdiffusion 121 tler Photoelektronen zur Kathode; bei kleinem E/p wird der verfiigbare I'rimlrstrom kleincr als der photoelektrisch ausgeloste 1'riniii.rstrom I,. -Ebcnso ist die gemeinsame Anfangs-Abszissc bei x = 0 nur eine hTaherung. Die Lawinenbildung beginnt erst bcli den ,,Startpunkten" 131 an der Stelle z w b w U J E , wobei U i = Ionisic.ruiigs-Potentia1, 6 = Anlaufstrecke. I n Abb. 1 fur CH30H (77, 7 10,8 V) sind dicse Startpunkte eingetragen. Erwar-

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Anomalies in Ionization Coefficients and in Uniform Field Breakdown in Argon for Low Values ofEp

Cited by 36 publications

References 17 publications

Uniform-field sparking voltages of gases in crossed magnetic fields

Uniform-field sparking voltages of gases in crossed magnetic fields

Surface behavior based on ion-induced secondary electron emission from semi-insulating materials in breakdown evolution

Townsend‐Koeffizient α für Alkoholdämpfe, Luft und Argon

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