DEVELOPMENT OF THE POSITRON INJECTOR FOR LEPTA FACILITY

V. Bykovsky¹, I. Meshkov¹, V. Pavlov¹, R. Pivin¹, A. Rudakov¹, G. Trubnikov¹, S. Yakovenkoª¹, M.K. Eseev²

¹Joint Institute for Nuclear Research, Dubna, Russia

²Lomonosov Pomor State University, Arkhangelsk, Russia

Abstract

An injector of the low energy positrons for the accumulator LEPTA has being assembled at JINR. The injector is based on ²²Na radioactive source. Positrons from the source are moderated in the solid neon. The cryogenic source of slow positrons has been tested with a isotope ²²Na of the initial activity of 0.8 MBk. The continuous slow positron beam with average energy of 1.2 eV, width of a spectrum 1 eV has been obtained. The achieved moderator efficiency is about 1 %.

The accumulation process in the positron trap was investigated with electron flux. The life time of the electrons in the trap, τ_life≥80 s and capture efficiency ε~0.4 have been obtained. The maximum number of the accumulated particle was N_exper = 2∙10⁸ at the initial flux of 5∙10⁶ electrons per sec.

ª – corresponding author

Paper Slides

382

PROJECT OF THE NUCLOTRON-BASED ION COLLIDER FACILITY (NICA) AT JINR

G. Trubnikov, N. Agapov, V. Alexandrov, A. Butenko, E.D. Donets, E.E. Donets, A. Eliseev, V. Kekelidze, H. Khodzhibagiyan, V. Kobets, A. Kovalenko, O. Kozlov, A. Kuznetsov, I. Meshkov, V. Mikhaylov, V. Monchinsky, V. Shevtsov, A. Sidorinª, A. Sissakian, A. Smirnov, A. Sorin, V. Toneev, V. Volkov, V. Zhabitsky, O. Brovko, I. Issinsky, A. Fateev, A. Philippov

Joint Institute for Nuclear Research, Dubna, Russia

Abstract

The Nuclotron-based Ion Collider fAcility (NICA) is a new accelerator complex being constructed at JINR aimed to provide collider experiments with heavy ions up to uranium at maximum energy (center of mass) equal to √s ~11 GeV/u. It includes new 6.2 MeV/u linac, 440 MeV/u booster, upgraded SC synchrotron Nuclotron and collider consisting of two SC rings, which provide average luminosity of 10²⁷cm^-2∙s^-1. The new facility will allow also an effective acceleration of light ions to the Nuclotron maximum energy and an increase of intensity of polarized deuteron beams up to the level above 10¹⁰ particles/cycle. Accelerator complex NICA is being built on the experience and technological developments at the Nuclotron facility and incorporates new technological concepts. The scheme of the facility, its operation scenario and beam dynamics are presented in the report.

ª – corresponding author

Paper Slides

82

STATUS OF THE LEPTA PROJECT

V. Bykovsky, E. Ahmanova, V.I. Kaplin, V.N. Karpinsky, A. Kobetsª, V. Lokhmatov, V. Malakhov, I. Meshkov, R. Pivin, A. Rudakov, G. Trubnikov, S. Yakovenko

Joint Institute for Nuclear Research, Dubna, Russia

Abstract

The project of the Low Energy Positron Toroidal Accumulator (LEPTA) is under development at JINR. The LEPTA facility is a small positron storage ring equipped with the electron cooling system. The project positron energy is of 4÷10 keV. The main goal of the facility is to generate an intense flux of positronium atoms – the bound state of electron and positron. The focusing system of the LEPTA ring after solenoidal magnetic field remeasurement and correction has been tested with pulsed electron beam by elements. Some resonant effects of beam focusing have been observed.

Storage ring of LEPTA facility was commissioned in September 2004. Since then the ring was equipped with additional beam diagnostics. The magnetic field quality in the ring was improved. Results of testing the storage ring with electron beam after the upgrade are presented. The experiments aiming to increase the life time of the circulating electron beam and test the electron cooling elector beam are in progress.

ª – corresponding author

Paper Slides

101