We present a new concept of an electron gun for generating subrelativistic few-femtosecond (fs) electron pulses. The basic idea is to utilize a dc acceleration stage combined with an RF cavity, the ac field of which generates an electron energy chirp for bunching at the target. To reduce space charge (SC) broadening the number of electrons in the bunch is reduced and the gun is operated at a me...

High-resolution field emission scanning electron microscopy (FESEM) is achieved through use of a field emission gun (FEG) in place of the more conventional tungsten hairpin or LaB6 filaments. A resolution of 0.5 nm has been achieved under ideal conditions and 5 nm is regularly achieved at 30 kV with conducting materials (Fig. 1). However, with insulating materials such as rocks this figure is c...

A surface charge compensation electron flood gun has been added to the Lawrence Livermore National Laboratory (LLNL) highly charged ion (HCI) emission microscope. HCI surface interaction results in a significant charge residue being left on the surface of insulators and semiconductors. This residual charge causes undesirable aberrations in the microscope images and a reduction of the time-of-fl...

The Linac Coherent Light Source (LCLS) is a SASE xray Free-Electron Laser (FEL) project presently under construction at SLAC [1]. The injector section, from drive-laser and RF photocathode gun through first bunch compressor chicane, was installed in fall 2006. Initial system commissioning with an electron beam has recently been completed. The second phase of construction, including second bunch...

An 1.6 cell rf-gun system has been installed at Waseda University for the generation of high charge, short pulse and low emittance electron beam. The gun is one of essential component for X-ray generation using inverse Compton scattering between photo electron bunch and laser pulse. An all-solid-state picosecond Nd:YLF laser system has been installed at Waseda University and will be used not on...

An electrostatic electron source design capable of producing sub-20 femtoseconds (rms) multi-electron pulses is presented. The photoelectron gun concept builds upon geometrical electric field enhancement at the cathode surface. Particle tracer simulations indicate the generation of extremely short bunches even beyond 40 cm of propagation. Comparisons with compact electron sources commonly used ...

Real-space imaging of full-morphological, angstrom-scale structural dynamics occurring on the femtosecond (fs) timescale is possible with ultrafast electron microscopy (UEM) via the stroboscopic pump-probe methodology enabled by interfacing an otherwise standard TEM with a short-pulsed laser system [1-3]. The technology has matured to the point that commercial systems, such as the FEI Tecnai Fe...