46 research outputs found
Useful formulas for non-magnetized electron cooling
Recent success of Low Energy RHIC Electron Cooler (LEReC) opened a road for
development of high energy electron coolers based on non-magnetized electron
bunches accelerated by RF cavities. Electrons in such coolers can have velocity
distribution with various unequal horizontal, vertical and longitudinal
velocity spreads. In this paper we revisit a formula of friction force in
non-magnetized cooling and derive a number of useful expressions for different
limiting cases
Mapping Digital Media: Russia
Examines trends in Russia's media system, including media consumption, media ownership, the use of television as an organ of executive power, and the effect of digital media on freedom of speech, pluralism, civic participation, and news quality
Proof-of-Principle Experiment for FEL-Based Coherent Electron Cooling,”
Abstract Coherent electron cooling (CEC) has a potential to significantly boost luminosity of high-energy, highintensity hadron-hadron and electron-hadron colliders. In a CEC system, a hadron beam interacts with a cooling electron beam. A perturbation of the electron density caused by ions is amplified and fed back to the ions to reduce the energy spread and the emittance of the ion beam. To demonstrate the feasibility of CEC we propose a proof-of-principle experiment at RHIC using SRF linac. In this paper, we describe the setup for CeC installed into one of RHIC's interaction regions. We present results of analytical estimates and results of initial simulations of cooling a gold-ion beam at 40 GeV/u energy via CeC
Longitudinal coupling impedance of a small hole in a coaxial liner near the cutoff frequencies
We recently developed a general analysis for an azimuthally asymmetric rectangular slot in the inner conductor of a coaxial liner, which allowed us to investigate the coupling impedance numerically. In the present paper we obtain analytic expressions for a small hole of arbitrary shape. Specifically, we go beyond the quasistatic (Bethe) approximation to explore and understand the structure of the impedance in the frequency region near the cutoffs of the inner beam pipe and outer coaxial structure. Finally, we extend our analytic analysis to a hole in a wall of finite thickness