LOW ENERGY POSITRON STORAGE RING FOR POSITRONIUM GENERATION: STATUS AND DEVELOPMENT

The project of Low Energy Particle Toroidal Accumulator (LEPTA) is dedicated to construction of a small positron storage ring with electron cooling of positrons circulating in the ring. Such a peculiarity of the LEPTA enables it automatically to be a generator of positronium (Ps) atoms, which appear in recombination of positrons with cooling electrons inside the cooling section of the ring. The Ps atoms form an intense, up to 10 +4 atoms/sec, flux which has very small angular, of order of 1 mrad, and momentum (less than 0.1%) spreads. The project has a few goals: to construct the LEPTA storage ring and to study its characteristics; to study particle dynamics in the ring; to set up first experiments with Ps in flight. At that time already the design of the storage ring and the elaboration of the technology of the ring elements manufacturing were done. The vacuum chamber of the ring was constructed and tested. Solenoid of electron cooling system was constructed, tested and adjusted. Other general elements of the magnetic system are under construction and will be delivered until the end of 2000. Injection system and detector for first experiments with positronium flux are under design.