Electron beam controller

An electron beam device which extracts energy from an electron beam before the electrons of the beam are captured by a collector apparatus is described. The device produces refocusing of a spent electron beam by minimizing tranverse electron velocities in the beam where the electrons, having a multiplicity of axial velocities, are sorted at high efficiency by collector electrodes

Dual field alignment display and control for electron micropattern generator

Application of electron beam lithography to replace photolithography process in fabrication of integrated circuits is discussed. Procedure for using electron beam lithography equipment is described. Diagram of electron micropattern generator is provided

Generation of Multi-Color Attosecond X-Ray Radiation Through Modulation Compression

In this paper, we propose a scheme to generate tunable multi-color attosecond coherent X-ray radiation for future light source applications. This scheme uses an energy chirped electron beam, a laser modulators, a laser chirper and two bunch compressors to generate a multi-spike prebunched kilo-Ampere current electron beam from a few tens Ampere electron beam out of a linac. Such an electron beam transports through a series of undulator radiators and bunch compressors to generate multi-color coherent X-ray radiation. As an illustration, we present an example to generate two attosecond pulses with $2.2$ nm and $3$ nm coherent X-ray radiation wavelength and more than $200$ MW peak power using a $30$ Ampere $200$ nm laser seeded electron beam

Saturation studies of the E-beam sustained discharge atomic xenon laser

In an electron beam sustained discharge xenon laser the discharge energy deposition has been varied in order to investigate the saturation effect on the xenon laser. The current density of the electron beam is varied separately in the range of 0.1-2.7 A/cm2 to obtain optimized discharge excitation conditions as a function of electron beam current density and gas pressure. An optimal fractional ionization f=3.5-4×10-5 is found, independent of the electron beam parameters. The synergy of electron beam and discharge excitation has resulted in a maximum specific energy of 15 J/l at a total gas pressure of 9 ba

Equilibrium ion distribution in the presence of clearing electrodes and its influence on electron dynamics

Here we compute the ion distribution produced by an electron beam when ion-clearing electrodes are installed. This ion density is established as an equilibrium between gas ionization and ion clearing. The transverse ion distributions are shown to strongly peak in the beam's center, producing very nonlinear forces on the electron beam. We will analyze perturbations to the beam properties by these nonlinear fields. To obtain reasonable simulation speeds, we develop fast algorithms that take advantage of adiabatic invariants and scaling properties of Maxwell's equations and the Lorentz force. Our results are very relevant for high current Energy Recovery Linacs, where ions are produced relatively quickly, and where clearing gaps in the electron beam cannot easily be used for ion elimination. The examples in this paper therefore use parameters of the Cornell Energy Recovery Linac project. For simplicity we only consider the case of a circular electron beam of changing diameter. However, we parameterize this model to approximate non-round beams well. We find suitable places for clearing electrodes and compute the equilibrium ion density and its effect on electron-emittance growth and halo development. We find that it is not sufficient to place clearing electrodes only at the minimum of the electron beam potential where ions are accumulated

Three-dimensional analysis of the surface mode supported in \v{C}erenkov and Smith-Purcell free-electron lasers

In \v{C}erenkov and Smith-Purcell free-electron lasers (FELs), a resonant interaction between the electron beam and the co-propagating surface mode can produce copious amount of coherent terahertz (THz) radiation. We perform a three-dimensional (3D) analysis of the surface mode, taking the effect of attenuation into account, and set up 3D Maxwell-Lorentz equations for both these systems. Based on this analysis, we determine the requirements on the electron beam parameters, i.e., beam emittance, beam size and beam current for the successful operation of a \v{C}erenkov FEL

Electron beam deflected to determine focal point location

System locates the focal point of an extremely high intensity electron beam. The electron beam is swept and scanned cyclically with deflection coils under a focusing lens, causing the beam focal point to move so the locus of its positions is a spherical surface symmetrical to the beam axis