Positron injector for LEPTA

Abstract

The injector of the low energy positrons for accumulator LEPTA is being assembled at JINR. The key elements of the injector have been tested. The cryogenic source of slow positrons has been tested with a test isotope 22 Na of the initial activity of 0.8 MBk. The continuous slow positron beam intensity of 5.8 · 10 3 s −1 with average energy of 1.2 eV and width of a spectrum 1 eV has been obtained. The achieved moderator efciency is about 1%. The accumulation process in the positron trap was investigated with electronux. Th e lifetime of the electrons in the trap, τlife 80 sa nd capture efciency e ∼ 0.4 have been obtained. The maximum number of the accumulated particle was Nexp =2 · 10 8 at the initialux of 5 · 10 6 e − /s. ‚ �ˆŸˆ § ¢¥·I ¥E¸O ¸iμ·± ¨³¶E²O¸´μ£μ ¨´|¥± Eμ· ¶μ§¨E·μ´μ¢ ´¨§±μ° O´¥·£¨¨ ¤²O E¸E - ´μ¢±¨ LEPTA. �·μ¢¥¤¥´μ O±¸¶¥·¨³¥´E ²O´μ¥ ¨ ¸¸²¥¤μ¢ ´¨¥ · iμEO μ¸´μ¢´OI E§²μ¢ ¨´|¥±Eμ· . ˆ¸¸²¥¤μ¢ ´ · iμE ±·¨μ£¥´´μ£μ ¨¸EμI´¨± ¶μ§¨E·μ´μ¢ ¸ E¥¸Eμ¢O³ ¨§μEμ¶μ³ 22 Na, ±E¨¢´μ¸EOO 0,8 Œ±. �μ²EI¥´ ¶EIμ± ³¥¤²¥´´OI ¶μ§¨E·μ´μ¢ ¨´E¥´¸¨¢´μ¸EOO 5,8 · 10 3 c −1 ¸μ ¸·¥¤´¥° O´¥·£¨¥° 1,2 O‚ ¶·¨ I¨·¨´¥ ¸¶¥±E· 1 O‚. "μ²O § ³¥¤²¥´´OI ¶μ§¨E·μ´μ¢ ¸μ¸E ¢¨² 1% μE ¶μ²´μ£μ ¶μ- Eμ± . �·μ¢¥¤¥´μ ¨¸¸²¥¤μ¢ ´¨¥ ¶·μI¥¸¸ ´ ±μ¶²¥´¨O I ¸E¨I ¢ ²μ¢EI±¥ ´ O²¥±E·μ´ I. ‚ ·¥§E²OE E¥ μ¶E¨³¨§ I¨¨ ¶ · ³¥E·μ¢ ²μ¢EI±¨ ¤μ¸E¨£´EEμ ¢·¥³O |¨§´¨ ´ ±μ¶²¥´´OI O²¥±E·μ´μ¢ τlife 80 ¸, OEE¥±E¨¢´μ¸EO § I¢ E e ∼ 0,4, IEμ ¸μμE¢¥E¸E¢E¥E ´ ¨²EII¨³ ·¥§E²OE E ³, ¶μ²EI¥´´O³ ¢ ²μ- ¢EI± I ¶μ¤μi´μ£μ E¨¶ . �·¨ OEμ³ ³ ±¸¨³ ²O´μ¥ I¨¸²μ ´ ±μ¶²¥´´OI I ¸E¨I Nexp =2 · 10 8 ¶·¨ ¶¥·¢μ´ I ²O´μ³ ¶μEμ±¥ 5 · 10 6 e − /¸.