Profile Monitor for Electron Beam in the High-Voltage Electron Cooling System of the COSY Synchrotron

Technical Physics - A high-voltage system for electron cooling of the COSY (Germany) synchrotron is featured by the presence of a profile monitor that is used for measurement of current density...     

Status of the High-Voltage Electron-Cooling System of the NICA Collider

Physics of Particles and Nuclei Letters - In order to achieve the design luminosity in the NICA collider, it is planned to equip it with both stochastic and electron cooling. The electron-cooling...     

Status of construction of the electron cooling system for the NICA booster

According to the agreement, the electron cooling system for the NICA booster should be commissioned in late 2015. The degree of completion of various units and components of the installation as of September 2015 is characterized in the present report. Part of the report is devoted to discussing the performance parameters of the installation and the engineering solutions that had to be implemented to achieve such parameters.     

Start of Electron Cooling System for the NICA Booster

In order to achieve the required beam parameters in the NICA booster, the electron cooling system (ECS) was designed and manufactured at the Institute of Nuclear Physics (INP), Novosibirsk. In 2017, the system was shipped to JINR and its assembly and commissioning started. A specific feature of this system is that, for the first time ever, the electron cooling method with a magnetized e-beam is applied at the superconducting synchrotron; this imposes some additional requirements for the design and start of the ECS, operating at room temperature. This paper describes the main steps of the ECS assembly and start at the straight section of the booster, including mounting mechanical, electrical, and plumbing systems (water, electricity, air, and oil system) and geodetic works on installing the system on site. The measured magnetic field homogeneity for the straight solenoid is given. The assembly of vacuum and magnet systems takes several steps because of the ECS design features. At the final assemblage stage of the vacuum system, the vacuum chamber is baked up and the bulk getters and the cathode of the electron gun are activated. Upon completing assembly and testing the high voltage system, the E-beam is conducted from the gun to the collector.     

Electron Collector for a High-Voltage Electron-Cooling System

Physics of Particles and Nuclei Letters - Electron-beam energy recuperation is usually used in electron-cooling systems (ECSs). The operation stability, vacuum conditions, and radiation background...     

Compact Electron Gun for High-Voltage Electron Cooling Systems

Physics of Particles and Nuclei Letters - One way to increase the efficiency of electron cooling is to increase the electron density in the beam reference frame. As a rule, with an increase in the...     

Design of the Central Solenoid of the HV Electron Cooling System for the NICA Collider

Physics of Particles and Nuclei Letters - The HV electron cooling system designed at the Budker Institute of Nuclear Physics for the NICA collider is the world’s only setup developed for a...     

Measuring of spatio-temporal characteristics Z-pinch from deuterated polyethylene

On the S-300 installation at currents up to 2 MA with rise time 100 ns, the investigation of the formation process of high-temperature plasma in fast Z-pinch was carried out. The central part of the loads was made from agar-agar and represented a deuterated polyethylene cylinder with small density 50 and 75 mg/sm³ and 1–2 mm diameter. On the ICT images, obtained in optical and soft X-ray range of a spectrum with 3–5 ns exposition, it is visible that on the axis of the polyethylene cylinder at the current`s rise time a cord is formed and it is separated into bright formations. They were observed on a background of a luminous area which occupied the initial neck volume. On time-integrated pinhole pictures obtained in SXR range (E > 1–4 keV), hot points with minimal size of 50 microns were registered. From the chronograms results, obtained by means of the optical high-speed-streak camera mount along the neck axis with time resolution < 1 ns, it follows that luminous formations arise sequentially during the different time moments (in 10–30 ns). Occurrence of luminous formations was accompanied by X-ray radiation occurrence with energy E > 1 keV with short duration of 2–4 ns. Simultaneously with X-ray radiation neutrons with the maximal yield of 4.5×10⁹ were registered. The average energy measured in 4 directions under angles with an axis of: 0^○ (above the anode), 90^○, 180^○ (under the cathode) and 270^○, were accordingly: 2.4±0.2, 2.5±0.1, 2.5±0.1, 2.5±0.1 MeV.     

Optical aberrations in a bent-crystal spectrometer

Aberrations in a bent-crystal X-ray spectrometer were studied by the methods of analytical geometry. Trigonometric equations describing aberrations in a real spectrometer were derived and solved by approximate techniques. The cases of crystal analyzers possessing spherical, toroidal, and cylindrical surfaces were considered. The investigation was aimed at evaluation of the resolving power of a spectrometer with an extended radiation source (tokamak plasma).     

Efficiency improvement of an electron collector intended for electron cooling systems using a Wien filter

An efficient collector for high-voltage systems of electron cooling is presented. Its efficiency (ratio of the reflected electron current to the current of the main beam) is greatly improved by suppressing the reflected particle flux in the Wien filter. Secondary electrons deflect in crossed transverse electric and magnetic fields and are absorbed by a special receiver plate (secondary collector). The filter is designed so that the whole backward flow of electrons deflects even if the trajectory and main beam profile are distorted insignificantly. Experiments carried out on a special-purpose test bench show that such a filter raises the efficiency of the collector hundredfold (up to 10^?6).