J. Phys. Colloques
Volume 49, Numéro C6, Novembre 198835th International Field Emission Symposium / 35éme Symposium International d'Emission de Champ
|Page(s)||C6-167 - C6-172|
J. Phys. Colloques 49 (1988) C6-167-C6-172
HIGH PULSED CURRENTS FROM PHOTO-FIELD EMITTERSH. BERGERET, M. BOUSSOUKAYA, R. CHEHAB, B. LEBLOND et J. LE DUFF
Université Paris-Sud, Institut National de Physique Nucléaire et de Physique des Particules, Laboratoire de l'Accélérateur Linéaire, Centre d'Orsay, F-91405 Orsay Cedex, France
Différent microemitters - single or arrays - with various geometries and kinds of material have been irradiated with pulsed laser beams. These emitters working in photo-field emission regime delivered very high intensity electron bunches. Peak intensities as high as some tens of Amps with less than one ns duration have been obtained with U.V. light. New type of microemitters developed in collaboration with BNL have been tested since last year showing the possibility of obtaining charges above 20 nC with low energy laser puises, (εi = 100µJ). The main parameters affecting the choice of these emitters as quantum yield, photocurrent density, electron pulse length, repetition rate and vacuum system level are here discussed. Good performances obtained with these emitters as well as the absence of cesiation make these microemitters interesting candidates for the new generation of linac injectors as well as for multimegawatt RF sources. At LAL, Orsay efforts have been made since three years to develop such electron sources.