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 efˇciency is about 1%. The accumulation process in the positron trap was investigated with electron ux. The lifetime of the electrons in the trap, τ life 80 s and capture efˇciency ε ∼ 0.4 have been obtained. The maximum number of the accumulated particle was Nexp = 2 · 10 8 at the initial ux of 5 · 10 6 e − /s. ‚ ˆŸˆ § ¢¥·Ï ¥É¸Ö¸¡μ·± ¨³ ¶Ê²Ó¸´μ£μ¨´¦¥±Éμ· ¶μ §¨É·μ´μ¢´¨ §±μ°Ô´¥·£¨¨¤²Ö Ê¸É -μ¢±¨LEPTA. ·μ¢¥¤¥´μ Ô±¸ ¶¥·¨³¥´É ²Ó´μ¥¨¸¸²¥¤μ¢ ´¨¥ · ¡μÉÒ μ¸´μ¢´ÒÌ Ê §²μ¢¨´¦¥±Éμ· .¸¸² ¥¤μ¢ ´ · ¡μÉ ±·¨μ£¥´´μ£μ¨¸Éμ䨱 ¶μ §¨É·μ´μ¢¸É¥¸Éμ¢Ò³¨ §μÉμ ¶μ³ 22 Na, ±É¨¢´μ¸ÉÓÕ 0,8 OE±. μ²ÊÎ¥´ ¶ÊÎμ± ³¥¤²¥´´ÒÌ ¶μ §¨É·μ´μ¢¨´É¥´¸¨¢´μ¸ÉÓÕ 5,8 · 10 3 c −1¸μ¸· ¥¤´¥°Ô´¥·£¨¥°1 ,2 Ô‚ ¶·¨Ï¨·¨´¥¸ ¶¥±É· 1 Ô‚. "μ²Ö § ³¥¤²¥´´ÒÌ ¶μ §¨É·μ´μ¢¸μ¸É ¢¨² 1% μÉ ¶μ²´μ£μ ¶μ-Éμ± . ·μ¢¥¤¥´μ¨¸¸²¥¤μ¢ ´¨¥ ¶·μÍ¥¸¸ ´ ±μ ¶²¥´¨Ö Î ¸É¨Í ¢ ²μ¢Êϱ¥´ Ô²¥±É·μ´ Ì. ‚ ·¥ §Ê²ÓÉ É¥ μ ¶É¨³¨ § ͨ¨ ¶ · ³¥É·μ¢ ²μ¢Êϱ¨¤μ¸É¨£´ÊÉμ ¢·¥³Ö ¦¨ §´¨´ ±μ ¶²¥´´ÒÌ Ô²¥±É·μ´μ¢ τ life 80¸, ÔËË¥±É¨¢´μ¸ÉÓ § Ì¢ É ε ∼ 0,4, ÎÉμ¸μμÉ¢¥É¸É¢Ê¥É´ ¨²ÊÎϨ³ ·¥ §Ê²ÓÉ É ³, ¶μ²ÊÎ¥´´Ò³ ¢ ²μ-¢Êϱ Ì ¶μ¤μ¡´μ£μ ɨ ¶ . ·¨ÔÉμ³ ³ ±¸¨³ ²Ó´μ¥ Ψ¸²μ´ ±μ ¶²¥´´ÒÌ Î ¸É¨Í Nexp = 2 · 10 8 ¶· ¶ ¥·¢μ´ Î ²Ó´μ³ ¶μÉμ±¥ 5 · 10 6 e − /¸.