If the energy spread of a beam is larger then the Pierce parameter, the FEL gain length increases dramatically and the FEL output gets suppressed. We show that if the energy distribution of such a beam is made oscillatory on a small scale, the gain length can be considerably decreased. Such an oscillatory energy distribution is generated by first modulating the beam energy with a laser via the ...

The cavity control system for the TESLA TeV–Energy Superconducting Linear Accelerator project is initially introduced. The elementary analysis of the cavity resonator on RF (radio frequency) level and low level frequency with signal and power considerations is presented. For the field vector detection the digital signal processing is proposed. The electromechanical model concerning Lorentz forc...

High gradients require high peak powers. One possible way to generate high peak powers is to generate a relatively long pulse at a relatively low power and compress it into a shorter pulse with higher peak power. It is possible to compress before DC to RF conversion as is done for the relativistic klystron or after DC to RF conversion as is done with SLED. In this note only radio frequency puls...

A pulse-forming network(PFN) with mutual coupling has been designed and built for the klystron pulse modulator of the SLAC Next Linear Collider(NLC). The PFN consists of a single-layer air-core coil with mutual coupling between sections and equal valued capacitors. The optimization of the coupling coefficient and the design of the air-core coil such as its radius, the number of turns and its to...

Multicavity Klystron (MCK) is a high power microwave (HPM) vacuum electronic device used to amplify radio-frequency (RF) signals with numerous applications, including radar, radio navigation, space communication, television, repeaters, and charged particle accelerators. The microwave-generating interactions in klystrons take place resonant cavities at discrete locations along the beam. Importan...

As a kind of artificially structured media, electromagnetic metamaterials (MTMs) have exotic properties that are not found or difficult to achieve in natural materials. This class metal/dielectric-structured artificial media has attracted great attention during the past two decades and made important breakthroughs. A variety passive active devices based on MTMs been developed rapidly. Especiall...