Download or read book tude par simulation de l mission de champ et de la photo mission de champ sur des photocathodes m talliques Dynamique du faisceau mis written by Hala Wattar Saleh and published by . This book was released on 1992 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: LA RECHERCHE DE NOUVELLES SOURCES D'ELECTRONS A FORT COURANT DEVIENT DE PLUS EN PLUS IMPORTANTE POUR LES FUTURS ACCELERATEURS: LE LASERTRON, LES PHOTOINJECTEURS DES LASERS A ELECTRONS LIBRES. APRES AVOIR EFFECTUE UNE BIBLIOGRAPHIE SUR L'EMISSION DE CHAMP, L'EMISSION PHOTOELECTRIQUE ET LA PHOTOEMISSION DE CHAMP, NOUS AVONS DEVELOPPE LE PRINCIPE DE LA METHODE DE RESOLUTION DES EQUATIONS DE CHAMP (L'EQUATION DE POISSON ET LES EQUATIONS DE MAXWELL) PAR LA METHODE DES ELEMENTS FINIS. LES RESULTATS DE NOS ETUDES ONT MONTRE L'EFFICACITE DU CODE PRIAM QUI POSSEDE LA POSSIBILITE DE RAFFINER LE MAILLAGE DANS LA ZONE DESIREE. IL EXISTE PLUSIEURS FACONS DE REDUIRE L'EFFET DE CHARGE D'ESPACE, NOTAMMENT LA DIMINUTION DE LA DUREE DE L'IMPULSION LASER, L'AUGMENTATION DE CHAMP ELECTRIQUE ET L'APPLICATION D'UN CHAMP MAGNETIQUE. DES CALCULS DE L'EMITTANCE TRANSVERSE POUR UNE PHOTOCATHODE PLANE ONT ETE FAITS A DIFFERENTS INSTANTS DE L'EMISSION. CES CALCULS MONTRENT QUE L'EMITTANCE TRANSVERSE EST FAIBLE AU DEBUT ET A LA FIN DE L'EMISSION ET QU'ELLE PASSE PAR UN MAXIMUM QUI POURRA ETRE A L'ORIGINE DE L'ECLATEMENT DU FAISCEAU ELECTRONIQUE POUR DES CHAMPS ELECTRIQUES FORTS. SI ON CHERCHE UNE EMITTANCE FAIBLE, ON DOIT ECLAIRER LA PHOTOCATHODE PAR DES IMPULSIONS LASER COURTES

Download or read book Physical Properties of Amorphous Materials written by David Adler and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Institute for Amorphous Studies was founded in 1982 as the international center for the investigation of amorphous mate rials. It has since played an important role in promoting the und er standing of disordered matter in general. An Institute lecture series on "Fundamentals of Amorphous Materials and Devices" was held during 1982-83 with distinguished speakers from universities and industry. These events were free and open to the public ,and were attended by many representatives of the scientific community. The lectures themselves were highly successful inasmuch as they provided not only formal instruction but also an opportunity for vigorous and stimulating debate. That last element could not be captured within the pages of a book I but the lectures concentrated on the latest advances in the field I which is why their essential contents are he re reproduced in collective form. Together they constitute an interdisciplinary status report of the field. The speakers brought many different viewpoints and a variety of back ground experiences io bear on the problems involved I but though language and conventions vary I the essential unity of the concerns is very clear I as indeed are the ultimate benefits of the many-sided approach.