I. N. Meshkov

Antihydrogen beam generation using storage rings

Abstract The scheme of antihydrogen beam generation is proposed. Two storage rings should be used for effective generation of antihydrogen - an antiproton ring and a small additional one for storing and cooling of positrons. This scheme has advantages compared with those discussed earlier due to the use of a longitudinal magnetic field as the focusing system of the positron ring with the positron source immersed in this field. The electron cooling of positrons is an essential part of the project. The Low Energy Antiproton Ring (LEAR) at CERN is chosen as the basic machine for idea demonstration and all the numerical applications are made for it. The rate of antihydrogen generation is limited in the case discussed here by the positron source intensity. The simplest version of this scheme permits one to achieve a rate of about 3 × 10 4 fast (50 MeV) atoms/s and 30 slow (0.5 MeV) ones. Simultaneously such a scheme is a generator of orthopositronium with a productivity of about 2 × 10 4 and 35 “atoms”/s, correspondingly. The particle dynamics in the positron storage ring are considered.

NICA PROJECT AT JINR

The project of Nuclotron-based Ion Collider fAcility NICA/MPD (MultiPurpose Detector) under development at JINR (Dubna) is presented. The general goals of the project are providing of colliding beams for experimental studies of both hot and dense strongly interacting baryonic matter and spin physics (in collisions of polarized protons and deuterons). The first program requires providing of heavy ion collisions in the energy range of \( \sqrt {S_{NN} } \) = 4−11 GeV1 at average luminosity of L = 1 × 1027 cm−2 s−1 for 197Au79+ nuclei. The polarized beams mode is proposed to be used in energy sNN = 12−27 GeV (protons at luminosity of L ≥ 1 × 1030 cm−2 s−1. The key issue of the Project is application of cooling methods—stochastic and electron ones. The report contains description of the facility scheme and characteristics in heavy ion operation mode, status and plans of the project development.

Conceptual design of the low energy positron storage ring

Abstract A method for the generation of intense antihydrogen and positronium streams using a low energy positron storage ring is considered. A longitudinal magnetic field for the focusing system and electron cooling of the positrons are essential features of the ring. The general limitations of the storage ring parameters are determined by the relation between scattering and cooling processes. The positron beam energy is determined by physics processes which are to be studied; it lies in the range from 5 up to 30 keV. The positron lifetime is about 100 s at a vacuum pressure of 100 pTorr. The generation of slow antihydrogen atoms by using electrostatic deceleration of positrons and antiprotons is described. The lowest antihydrogen energy in such a scheme is about a few eV and the generation rate is about 1 atom per second. The positron storage ring design is described. The general parameters of the positron storage ring, which is under design in JINR, are presented. The main purpose of the proposed machine construction is the performance of experimental studies of intense positron beam storing, electron cooling and deceleration in a straight section.

NICA at JINR: New prospects for exploration of quark-gluon matter

A new scientific program is proposed at the Joint Institute for Nuclear Research (JINR) in Dubna aimed at studies of hot and dense baryonic matter in the wide energy range from 2 GeV/u kinetic energy in fixed target experiments to

THE ANTIHYDROGEN AND POSITRONIUM GENERATION AND STUDIES USING STORAGE RINGS

\sqrt {s_{NN} } = 4 - 11

Status of the Development of Superconducting Magnets for the NICA Project

GeV/u in the collider mode. To realize this program the development of the JINR accelerator facility in high-energy physics (HEP) has been started. This facility is based on the existing superconducting synchrotron—the Nuclotron. The program foresees both experiments at the beams extracted from the Nuclotron, and the construction of a heavy-ion collider—the Nuclotron-based Ion Collider fAcility (NICA) which is designed to reach the required parameters with an average luminosity of L = 1027 cm−2 s−1.

Electron cooling — recent developments and trends

NICA is the new accelerator complex being under design and construction at JINR. The facility is aimed at providing collider experiments with heavy ions up to Uranium in a center of mass energy range from 4 to 11 GeV/u and an average luminosity up to 1027 cm-2 · s-1. The collisions of polarized deuterons are also foreseen. The facility includes two injector chains, a new superconducting Booster synchrotron, the existing 6 A · GeV superconducting synchrotron-Nuclotron, and the new superconducting Collider consisting of two rings of about 500 m circumference each. The Booster synchrotron and the NICA Collider are based on an iron-dominated “window frame”- type magnet with a hollow superconductor winding analogous to the Nuclotron magnet. The status of the design and construction of the full size model magnets for the Booster synchrotron as well as for the NICA Collider is presented.

Electron cooling — the first 30 years and thereafter

Abstract The scheme of antihydrogen generation using storage rings proposed recently [1] permits one to obtain intense and fine directed fluxes of antihydrogen and orthopositronium atoms. Experimental studies of such objects demand a specific experiment set-up. The possibility to generate extremely slow atoms is of special interest. Further development of the proposed scheme and possible experimental studies of generated atoms are discussed in this report.