<title>Formation of subfemtosecond photoelectron bunches in time-dependent electric fields</title>

Abstract

In the paper new theoretical aspects of temporal focusing of photoelectron bunch in time-dependent fields are elucidated. The results of computer modeling on electron-optical system with combined time-dependent electric and static magnetic fields which ensure both spatial focusing of the bunch and its temporal compressing up to the subfemtosecond level are presented.

Computer modeling of a subfemtosecond photoelectron gun with time-dependent electric field for TRED experiments

“…Special design of the "temporal" lenses and the use of additional magnetic focusing make it possible to compensate for some second-order temporal aberrations and gain the bunch duration of less then one femtosecond nearby the photoelectron gun crossover. 4. It has been shown that space charge repulsion in the dynamic photoelectron gun is not so crucial as in the static one.…”

“…It is important that such statement of the problem opens to us a possibility of temporal compressing of photoelectron bunches with the use of time-depending fields. As shown in 3,4 , the most remarkable thing here is that, in full similarity to the case of spatial focusing, the first-order temporal chromatic aberration can be made strictly equal to zero at the point of temporal focusing in a properly chosen time-dependent field. a Send correspondence to Mikhail A. Monastyrskiy: e-mail: monast@ran.gpi.ru, tel: (7095) 132-8184, (7095) 135-3265.…”

Numerical estimation of space-charge interaction in ultrashort electron bunches

“…The way to compress the electron bunch beyond this limit was proposed by the authors in 6 . It consists in temporal focusing of the bunch with the use of non-stationary electric field, similarly to the principle being employed for electron grouping in klystrons.…”