Joshi Effect Research Articles

Irreversible joshi effect: Its thermionic analogue

Irreversible joshi effect: Its thermionic analogue

Simultaneous occurrence of the corona pressure and positive Joshi effect in hydrogen

Simultaneous occurrence of the corona pressure and positive Joshi effect in hydrogen

Influence of tube walls on Joshi effect in iodine vapour

Influence of tube walls on Joshi effect in iodine vapour

The corona pressure effect (Δp) and the thermionic analogue of the Joshi effect (Δi)T in hydrogen in a semi-ionizer

Conditions favourable for the co-occurrence of the corona pressure effect and the thermionic analogue of the Joshi effect are determined and a study is made to find whether the corona pressure data can be used to interpret the mechanism of Δi.

Surface Origin of Joshi Effect in Carbon Monoxide

Surface Origin of Joshi Effect in Carbon Monoxide

Thermionic Analogue of Joshi Effect in Maze Type Counter in Argon

>Experiments are carried out to explain the occurrence of Joshi Effect in a free electron'' gas such as argon. The infiuence of increased thermionic emission on the discharge current is also studied. (auth)

Suppression of the Discharge in Iodine Vapour due to Radio-iodine (131I)†

The addition of radio-iodine (I¹³¹) to iodine vapor under discharge (0.5 mC/g) leads to a current suppression of 30 to 60% under a-c and nearly 100% under d-c excitation. With the decay of radio-iodine, the suppression diminishes progressively. Results are explained on the basis of increased dead time' of the system due to the cropping up of positive ions (formed by radiations from I¹³¹) throughout the gas phase. Their accumulation suppresses the discharge, which may be considered as the analogue of Joshi effect due to internal irradiation. (auth)

Thermionic analogue of the Joshi effect

The Joshi effect is shown to exist in an electrodeless discharge in air when a central wire emits electrons. This is compared with the effects observed when irradiation is produced by ultra-violet or visible light.

Simultaneous Occurrence of the Corona Pressure and Joshi Effect in Argon

Simultaneous Occurrence of the Corona Pressure and Joshi Effect in Argon

Photosensitivity and Joshi Effect in Counters†

Abstract Joshi effect (±δi) an almost instantaneous and reversible photo-variation of the discharge current (i), is studied in various types of discharge vessels, charged with air, H2 and I2 vapour, and excited by fields due to continuous and alternating potentials (V). t was observed by a counter-sealer, and/or a galvanometer after rectification. +δi was observed under β-rays from a 50 millicurie Ra-Be source, and various frequency bands of the visible. The intensity (I) was varied over 30 times using the former, and 500 times with the latter. A 100% negative effect is observed near and above the threshold Vm; it decreases with increase of V. ± δi (disfavoured by a prolonged discharge) occurs within a restricted range of conditions, viz. low J and V. As these are increased, a sharp inversion equation follows which is fully reversible in respect of I and V. The minimum inversion intensity and the inversion potential vary in the order: violet < blue < green < yellow < red and, I2 H2 < air. ±δi is independe...

Dependence of the Joshi Effect on `Ageing' under, or and in the Absence of, Continuous Electrical Excitation

Dependence of the Joshi Effect on `Ageing' under, or and in the Absence of, Continuous Electrical Excitation

A Possible Mechanism of the Potential Variation of the Joshi Effect

A Possible Mechanism of the Potential Variation of the Joshi Effect

Starting potential for the coaxial cylinder coronas in hydrogen under low frequency silent electric discharge

The starting potential for the low frequency silent electric discharge between coaxial glass cylinders has been measured over a range of pressure from 3 to 700 mm Hg. It is suggested that the starting potential is analogous to the intermittent pre-onset burst pulse corona. The other onset potentials have been evaluated from the current-potential characteristics and agree closely with those evaluated from the variation of the Joshi effect.

Spectral sensitivity of neon discharge tubes

The relative photoresponse of certain types of neon discharge tubes to irradiation at different wavelengths has been investigated by spectrophotometric methods. The experimental results, using a large number of discharge tubes, are expressed graphically as relative photoresponse for equal energy of incident radiation plotted against wavelength. The curves show that the discharge tubes act like photoemissive cells with caesium alloy cathodes. It is suggested that the photosensitivity is due to the positive Joshi effect as well as to the presence of ceasium on the tube electrodes.

Temperature as a Determinant of the Potential Inversion of the Joshi Effect

Temperature as a Determinant of the Potential Inversion of the Joshi Effect

Role of continued excitation in the potential inversion of the joshi effect

Role of continued excitation in the potential inversion of the joshi effect

Temperature as a Determinant of the Potential Inversion of the Joshi Effect

Temperature as a Determinant of the Potential Inversion of the Joshi Effect

Surface dependence of Joshi effect in water vapour under low frequency electric discharge

Detailed investigations on the dependence of theJoshi effect (±Δi) on the nature of the electrode surface were reported.Δi in water vapour could not be detected in vessels of which the free alkali existing on the electrode surface was removed by acidtreatment. Photo-suppression of the current (−Δi) could be initiated by films like KCl, NaCl, NaOH, etc. deposited or produced on glass surface during continued exposure to discharge. −Δi was linearly variant with the surface area exposed to light; the slope of the line was altered appreciably by a change in the nature of the electrode surface. Detailed studies with films like KCl, Al2O3 and H3PO4 not only revealed the significance of the polar nature of the films, but also indicated the prominent role of the dissociation-recombination processes (H2O⇌ H+OH) occurrent on the electrode surface, in controlling the magnitude and even the sign of the effectΔi. Remarkably enough, when the surface reaction was inhibited, an increase of the current under light, referred to as +Δi, was noticed.

Production of the Joshi effect in oxygen under the near infrared

Production of the Joshi effect in oxygen under the near infrared

A Remark on the Excitement of the Electrodes when a Positive Joshi Effect Inversion is Observed under Continuous Discharge

A Remark on the Excitement of the Electrodes when a Positive Joshi Effect Inversion is Observed under Continuous Discharge