Maxim Bryzgunov

Recuperation of Electron Beam in the Coolers with Electrostatic Bending

An important aspect of the cooler operation is the collector efficiency. The low loss current improves the vacuum condition, the radiation condition and makes the easy design of the power supply system. This article deals with the reuse of collector at the electrostatic bending in the toroidal section. It’s possible to compensate the centrifugal force for the secondary electrons by the electric field because the effect of both forces is independent from the direction of the electron longitudinal velocity. As result the secondary electrons may return into the collector after reflection from the gun. Nonzero loss current is defined mainly by the energy spectrum of the secondary electrons. The review of the experimental data for the different cooler is described in this article. The range of the electron energy is 2 – 300 keV. Some physical model is proposed for the experiment explanations.

High voltage electron cooling in ion colliders

Results of calculations of high voltage electron cooling process in NICA collider are presented. Two independent electron cooling systems in the collider are intended to increase luminosity in space charge dominated regime. The model of cooling calculations was tested on experimental results, obtained in COSY synchrotron, which is equipped with 2 MeV electron cooler, produced by Budker INP. Also a project of high voltage electron cooling systems for the NICA collider is presented.

High Efficiency Electron Collector for the High Voltage Electron Cooling System of COSY

A high efficiency electron collector for the COSY high voltage electron cooling system was developed. The main feature of the collector is usage of special insertion (Wien filter) before the main collector, which deflects secondary electron flux to special secondary collector, preventing them fly to the electrostatic tube. In first tests of the collector in COSY cooler efficiency of recuperation better then 10⁻⁵ was reached. Before assembling of the cooler in Julich upgrades of the collector and electron gun were made. After the upgrade efficiency better then 10-6 was reached. Design and testing results of the collector are described.

Features of cooling dynamics in a high-voltage electron cooling system of the COSY

An electron cooler designed at the Budker Institute of Nuclear Physics for the Cooler Synchrotron COSY (Juelich, Germany) has been put into operation. The aim of this cooling device is to prevent the beam scattering on an internal target up to the maximal energy of the transmitted beam. The device provides cooling in a strong longitudinal magnetic field generated in a high-voltage area. The motion of electrons in the magnetic field considerably improves the kinetics of electron—ion collisions, because their transverse velocity component (which is very high as a rule) does not participate in the process. First experiments on electron beam cooling on energy 200 MeV were made in 2013. Early in 2014, sessions on electron beam cooling to 200, 350, 580, and 1660 MeV were carried out. In other experiments, deuterium beams were cooled down. Experimental data for the cooling time are compared with the respective theoretical predictions. These results may be used in cooling projects for the Nuclotron-based Ion Collider fAcility (NICA), Joint Institute for Nuclear Research, Dubna, Russia, and the Facility for Antiproton and Ion Research (FAIR), Darmstadt, Germany.

The precision high voltage power supply system for the accelerating column of the 2MeV electron cooler for COSY

In the recent few years 2 MeV electron cooler was produced in Budker Institute of Nuclear Physics and assembled at the COSY storage ring (FZJ, Germany). The electrostatic accelerating column generates a high-energy electron beam. The power supply for the accelerating column of the electron cooling system consists of 33 controlled modules distributed by the accelerating potential. Each module has a precision controlled voltage source for 60 kV, 1mA and an additional supply for the solenoids of the magnetic system with a maximum current of 2.5 A. All the systems are controlled through the wireless ZIGBEE network. This report presents the structure of the power supply system, its parameters, and the results of tests carried out at BINP and FZJ.