[ 1 ] Linear accelerators producing relativistic (5 MeV) electron beams are now down to a size that allows them to be flown on spacecraft and sounding rockets. This opens up new opportunities for atmospheric/ionospheric modification experiments where the mesosphere and lower thermosphere regions can be perturbed down to 40-km altitude. In this paper the relativistic electron beam injection proc...

Electron injectors delivering relativistic electron beams with very high brightness are essential for a number of current and proposed electron accelerator applications. These high brightness beams are generally produced from photoemission cathodes. We formulate a limit on the electron beam brightness from such cathodes set by the transverse thermal energy of the electrons leaving the photocath...

Above the polar cap, at about 5–9 Earth radii (RE) altitude, the PEACE experiment onboard CLUSTER detected, for the first time, electron beams outflowing from the ionosphere with large and variable energy fluxes, well collimated along the magnetic field lines. All these events occurred during periods of northward or weak interplanetary magnetic field (IMF). These outflowing beams were generally...

Tumours and other superficial targets are often treated with electron beams in radiotherapy. The build-up dose and the therapeutic range of electrons are controlled by selecting the electron energy and by using a water-equivalent bolus placed on the skin. Currently, the shaping of clinical electron beams is often done via low melting point alloy block inserts individually made for each patient....

Electron vortex beams constitute the first class of matter vortex beams which are currently routinely produced in the laboratory. Here, we briefly review the progress of this nascent field and put forward a natural quantum basis set which we show is suitable for the description of electron vortex beams. The normal modes are truncated Bessel beams (TBBs) defined in the aperture plane or the Four...