In order to model fuse operation during circuit interruption, a detailed mass and energy transport analysis is needed. In this paper, using a novel method, the mass flow of the fuse element material, silver for this example, is presented. By neutron activation of part of the element, we are able, after interruption, to trace the distribution of the dispersed element material. We show that there is a silver mass coming from the arc ignition zone to the extremities, mainly in the direction of the anode.

Dielectric measurement characteristics such as the dissipation factor, relative permittivity and conductivity as a function of temperature and frequency have been achieved on composite materials based on different epoxy resins filled with alumina inclusions. The analysis of the results show the presence of porosity and inhomogeneity in these materials. The study of the dissipation factor, as a function of temperature at high frequencies, has shown an unexpected absorption phenomenon in materials designed to be utilized as electrical insulators. The identification of the entities responsible for this relaxation shows that the entities result from one of the components of the material. These results can also confirm the inhomogeneity of the materials.

Dans cet article, nous developpons une methode permettant de determiner le courant traversant un disjoncteur lors d'une coupure. Cette methode utilise un systeme optoelectronique constitue d'une fibre optique fluorescente couplee a un photodetecteur. L'onde du courant d'arc est obtenue a partir de l'onde lumineuse recue par le systeme de detection.

The aim of this study was to demonstrate the correlation between the light emitted by electric arc and its different parameters such as the current, voltage and power. The correlation is determined by two method of analysis: temporal and statistical correlation.

2014 Nous décrivons un spectromètre de paires comportant des chambres à étincelles à lecture par magnétostriction utilisé pour étudier la matérialisation de photons dans le champ des électrons atomiques.Un calculateur Varian 620 i en ligne permet de stocker les données sur bandes magnétiques.

Nous decrivons un dispositif experimental permettant l'etude de la production de triplets par des photons de rayonnement de freinage (140 a 210 MeV) sur une cible d'helium gazeux. L'analyse de l'electron de recul se fait a l'aide d'une chambre a streamers placee dans un champ magnetique (800 Gauss) coaxial au faisceau de photons. Les caracteristiques des electrons de materialisation sont obtenues grâce a un champ magnetique (12 000 Gauss) et quatre chambres a etincelles. Nous donnons les resultats preliminaires sur la section efficace totale de triplets.

E x p e r i m e n t a l r e s u l t s c o n c e r n i n g t h e t o t a l c r o s s s e c t i o n f o r p r o d u c t i o n o f e l e c t r o n p a i r s by p h o t o n s i n t h e f i e l d o f a n a t o m i c e l e c t r o n was n o t i n agreement w i t h t h e o r y . We r e a l i z e d a n e x p e r i m e n t u s i n g e m u l s i o n s , w i t h photons produced by B r e m s s t r a h l u n g o f e l e c t r o n s a b o u t 200 MeV/c. We a n a l i z e d 18 452 e v e n t s ( p a i r s and t r i p l e t s ) . A l 1 c o r r e c t i o n s f a c t o r s b e i n g i n t r o d u c e d we o b t a i n e d an e x p e r i m e n t a l c r o s s s e c t i o n i n good agreement w i t h t h e o r e t i c a l p r e d i c t i o n s o f B o r s e l l i n o and Mork. Le f a i s c e a u d e p h o t o n s d u r c i p a r p a s s a g e d a n s une co lonne d ' h y d r u r e de l i t h i u m p o u r d i m i n u e r l a p r o p o r t i o n d e p h o t o n s d e b a s s e é n e r g i e (1 1, e s t p e r p e n d i c u l a i r e au p l a n d e s é m u l s i o n s [ c e t t e d i s p o s i t i o n augmente en p a r t i c u l i e r l a r a p i d i t é d e r e c h e r c h e d e s événements ( 1 ) . Nous c h o i s i s s o n s , d a n s chaque émuls ion a n a l y s é e , une t r a n c h e où l a r e c h e r c h e e s t i s o t r o p e , e x e n p t e d e b i a i s s y s t é m a t i q u e s i m p o r t a n t s e t p o u r l a q u e l l e l ' e f f i c a c i t é d e l a r e c h e r c h e d e s événements d e m a t é r i a l i s a t i o n e s t d e 96 % (21. Nous c o n s i d é r o n s que l e s événements q u i p r é s e n t e n t un é l e c t r o n d e r e c u l a v e c une i o n i s a t i o n c r o i s s a n t e quand on s ' é l o i g n e d e l ' o r i g i n e d e l a p a i r e , s o n t d e s " t r i p l e t s expér i m e n t a u x " (31. Cependant , s i l ' é l e c t r o n d e r e c u l p r é s e n t e une l a c u n e i m p o r t a n t e lo à l ' o r i g i n e [ F i g u r e 1 1 , un c a l c u l s t a t i s t i q u e , b a s é sur l a l o i d e d i s t r i b u t i o n d e s l a c u n e s permet d e r e t e n i r ou non l ' événement comme " t r i p l e t e x p é r i m e n t a l " . P o u r un nombre g l o b a l d e 1 8 452 événements a n a l y s é s , nous o b t e n o n s , d a n s c e s c o n d i t i o n s , 13 769 " p a i r e s e x p é r i m e n t a l e s " , 521 " t r i p l e t s expér imentaux" , 38 événements non i d e n t i f i é s p r é s e n t a n t un b r u i t d e f o n d i m p o r t a n t , p r è s d e l ' o r i g i n e . Nous é v a l u o n s à 229 l e nombre t o t a l d e " f a u x t r i p l e t s " d u s à l ' a s s o c i a t i o n d ' u n e p a i r e e t d ' u n é l e c t r o n a tomique " é j e c t é " à moins d' lpm d e l ' o r i g i n e d e l a p a i r e . p a r choc coulomb i e n a v e c un d e s é l e c t r o n s e + ou e-. Nous mont rons que l a p r o b a b i l i t é qu 'un "Compton" n a i s s e p r è s d e l ' o r i g i n e d ' u n événement d e m a t é r i a l i s a t i o n e s t n é g l i g e a b l e . cre lacune