The LCLS Free-Electron Lasers operates in the wavelength range of 1.5 15 Angstrom, using an electron beam with an energy between 4.5 and 14.5 GeV. The generation of the electron beam, the preservation of its brightness during acceleration and compression, and the amplification of the spontaneous radiation within the FEL can only be described by a consistent set of simulation codes. We present t...

Limits of the electron beam density in the focus are evaluated. As it shown, the maximal beam density is achievable in the relativistic vacuum diode with the needle anode. In such a device, the initial emittance of a beam is rather small. The electron beam gains emittance while being focused with positive ions into the anode due to collisions with the ions. Based on the paraxial beam model, the...

HDPE monofilaments were obtained using different extruders and drawn by post-extruder equipments. After solidification, drawn and undrawn monofilaments (draw ratio 7:1) were irradiated with 10 MeV electron beams in air at room temperature at 25, 50, 75, 100 and 125 kGy dose ranges to induce a network structure. HDPE crosslinking was studied on the basis of gel content measurements. The fibers w...

At the LHC, the effect of unavoidable long-range beam–beam collisions reduces the dynamic aperture, calling for a minimum crossing angle. A wire compensator partially cancels the effect of the long-range collisions, and may allow operation with reduced crossing angle or decreased beta function at the interaction point, thereby increasing the (virtual) peak luminosity. In this chapter, we descri...

A photocathode-based low-emittance femtosecondbunch electron source is developed in Osaka University to reveal the hidden dynamics of intricate molecular and atomic processes in materials through experimentation such as time-resolved pulse radiolysis or time-resolved electron diffraction. The transverse and longitudinal dynamics of femtosecond electron beam in the photocathode rf gun were studi...

We have computed the Lyman continuum intensities for different flare circumstances, namely, the temperature rise in the chromosphere, the downward shift of the transition region, and the nonthermal effect of a precipitating beam of electrons. All the three factors can enhance the intensity by various amounts. The third effect additionally lowers the color temperature of the Lyman continuum. It ...