UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

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2024-11-23 18:17
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Conference: Bucharest University Faculty of Physics 2002 Meeting


Section: Optics, Spectroscopy, Plasma and Lasers


Title:
THE ROLE OF SPATIAL ELECTRIC CHARGE IN DETERMINING THE CARRIAGE CURRENT THROUGH IONISED MEDIA


Authors:
Benedict Oprescu, Daniela Giosanu


Affiliation:
University of Piteşti, Departament of Physics, Târgul din Vale Street, no.1, 0300-Piteşti,

e-mail:giosanu@yahoo.com


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Keywords:


Abstract:
The paper’s aim is to demonstrate the relative contribution of the spatial electric charge in determining the stationary regimen in ionised media. By studying the time evolution of the parameters caracteristic of the discharge (current and potential), several transition regimens towards the stationary state have been discovered. Their occurrence is due to the dominance of one of the microscopic mechanisms that are to be found in electrolythic conduction. Experimental study and the theoretical considerations regarding the passing of the current to the stationary regimen in electrolythic solution have led us to the following conclusiones: 1 Applying a “step” signal between the electrodes leads to establishing a stationary regimen after a time interval, during which the intensity of the electric current decreases in a monotonous manner; 2 When the amplitude of the signal applied does not exceed 9V, the establishing of the stationary regimen is mainly due to the appearance of a positive electric charge in front of the cathode; 3 For a signal applied whose amplitude ranges from 9V to 18V, the dominant factors is establishing the stationary regimen and the alteration of the contact potential and the appearance of a potential gradient in the electrolythe. This is due to the concentration gradient that has appeared in front of the electrodes; 4 When the amplitude of the signal applied exceeds 18V, the establishing of the stationary regimen is initially due to the appearance of a negative electric charge in front of the cathode. Subsequently, the phenomena generated by the concentration gradient become dominant.