In the Jefferson Lab (JLab) Electron Ion Collider (JLEIC) project the traditional electron cooling technique is used to reduce the ion beam emittance at the booster ring, and to compensate the intrabeam scattering effect and maintain the ion beam emittance during the collision at the collider ring. Different with other electron coolers using DC electron beam, the proposed electron cooler at the...

In modern storage rings the transverse emittance of electron beams can be comparable to that from state-of-art photoinjectors, but the intrinsic low peak current and large energy spread precludes the possibility of realizing short-wavelength high-gain free electron lasers (FELs) in storage rings. In this note I propose a technique to significantly increase beam peak current without greatly incr...

We propose a novel method for tailoring the current distribution of relativistic electron bunches. The technique relies on a recently proposed transverse-to-longitudinal phase space exchange. The bunch is transversely shaped and the phase space exchange mechanism converts this transverse profile into a current profile. The technique provides a tool for generating arbitrary current profiles in a...

A scheme is proposed to exchange the transverse and longitudinal emittances of an electron bunch. A general analysis is presented and a specific beamline is used as an example where the emittance exchange is achieved by placing a transverse deflecting mode radio-frequency cavity in a magnetic chicane. In addition to reducing the transverse emittance, the bunch length is also simultaneously comp...

The construction of a double discharge pulsed electron beam generator and the study of the characteristics of the beam are presented in this paper. The electron beam generator consists of a fast filamentary discharge in superposition with an ordinary glow discharge in low-pressure gases. The filling gas is argon or helium at approximately 0.1 Torr pressure. The duration of the electron beam is ...

We analyze the contrast reversal of Kikuchi bands that can be seen in electron backscatter diffraction (EBSD) patterns under specific experimental conditions. The observed effect can be reproduced using dynamical electron diffraction calculations. Two crucial contributions are identified to be at work: First, the incident beam creates a depth distribution of incoherently backscattered electrons...

The EicC (The highly polarized Electron-ion collider in China) project proposes a scheme with different numbers of bunches the two rings, which leads to an asymmetric beam-beam effect, also known as gear-change effect. In order investigate feasibility collision EicC, self-consistent simulation program named athenagpu, uses GPU for high-performance computing, was developed. A linearized matrix m...

A method of electron beam cooling is considered which can be used for linear colliders. The electron beam is cooled during collision with focused powerful laser pulse. The ultimate transverse emittances are much below those achievable by other methods. This method is especially useful for high energy gamma-gamma colliders. In this paper we review and analyse limitations in this method, also dis...

Mutually driven transverse oscillations of an electron beam and residual gas ions may result in a fast transverse instability. This effect arises either during a single pass of a train of electron bunches or it is caused by ionization electrons oscillating within a single positron bunch. In both cases, the beam oscillations grow exponentially with an exponent proportional to the square root of ...