Ultrafast electron diffraction (UED) is a powerful method for studying time-resolved structural changes. Currently, space charge induced temporal broadening prevents obtaining high brightness electron pulses with sub-100 fs durations limiting the range of phenomena that can be studied with this technique. We review the state of the the art of UED in this respect and propose a practical design f...

A frontier challenge in implementing femtosecond electron microscopy is to gain precise optical control of intense beams to mitigate collective space charge effects for significantly improving the throughput. Here, we explore the flexible uses of an RF cavity as a longitudinal lens in a high-intensity beam column for condensing the electron beams both temporally and spectrally, relevant to the ...

Closed-circuit television adapts well to the educational aspects of electron microscopy in terms of extending immediate student participation. The advantages and some examples of the dual role in education and research of such a system are presented. A research electron microscope is invariably called upon to flex its educational muscles. One which does so regularly is operated by the Iowa Stat...

Nanostructured zinc oxide (ZnO) materials have received considerable interest from scientists due to their remarkable performance in electronics, optics and photonics. ZnO nanoparticles were synthesized by co-precipitation method. ZnO nanoparticles were synthesized using Zn(NO3)3 and K2CO3 precursors. The structure of the obtained product was confirmed by the powder X-ray diffraction (XRD) anal...

The emission optics of a Steigerwald type electron gun is re-examined. The virtual and real points of divergence, divergence angles and beam-widths of the electron beams at different telefocusing strength are measured in detail for first time . Two different Wehnelt cylinders are used to establish a contrasting viewpoint. The original ‘focusing’ curves measured by Braucks are reconstructed and ...

The particle optics code GPT [1] has been applied to study the single pass electron beam interaction with an external laser field in the undulator system of a free electron laser. In particular, this code has been used to simulate the laser electron beam interaction in an optical klystron. Micro-bunching as a result of the interaction of the electron bunch with an electromagnetic pulse is prese...

The low-energy electronic excitations in graphene are described by massless Dirac fermions that have a linear dispersion relation. Taking advantage of this 'optics-like' electron dynamics, generic optical elements like lenses and wave guides have been proposed for electrons in graphene. Tuning of these elements relies on the ability to adjust the carrier concentration in defined areas. However,...

An electron collimator composed of a point-like source and a parabolic pn junction is proposed as a generator of highly focused electron beams in graphene. The collimator is based on negative refraction and Klein collimation, which are unique to pseudo-relativistic Dirac materials. The electron beams generated by the lensing apparatus can be steered by a weak magnetic field without losing colli...

Detailed assessment of the peculiarities of erythrocyte morphology by applying scanning electron microscopy and light-optics methods gives valuable information on the age characteristics, functional failures of the erythrocyte, pathogenesis of anaemia, and also diagnosis. In toxic anaemia caused by the chronic effect of lead and chlorobenzene there is accumulation of aging erythrocytes in blood...

An undulator-based beamline was built and commissioned at the National Synchrotron Light Source to provide tunable coherent radiation in the 200-800 eV range. The low emittance of the storage ring means that the undulator source has high brightness so that a large flux of coherent x rays is delivered to experimental stations. The beamline uses a horizontally dispersing bichromator that allows t...