The goal of our experiment is to collect alkali atoms in a magneto-optical trap (MOT) for high-precision spec- troscopy and for the study of parity violation in atomic sys- tems. We are focusing on francium isotopes, which are particularly suitable for these purposes. The production of francium is achieved by sending a 100-MeV 18 O beam from the Tandem-XTU accelerator on a thick gold target. The extraction of Fr+ is enhanced by heating the target to 1200 K and by biasing it at +3 kV. The ions are transported to the magneto-optical trap (MOT) through an 8-m electro- static beam line. The diagnostic systems for monitoring the beam intensity (about 10^5 ions/s) are based on silicon surface- barrier detectors sensitive to the α particles from Fr de- cays. Beams of stable Rb+ can also be used for optimizing the transport and trapping processes. At injection into the MOT cell, the beam is neutralized and released in atomic form by a heated yttrium foil. Details on Fr production, transport and neutralization are presented.
Production and transport of radioactive francium for magneto-optical trapping
STANCARI, Giulio;ATOUTOV, Serguei;CALABRESE, Roberto;GUIDI, Vincenzo;MAI, Bruno;TOMASSETTI, Luca;A. Khanbekyan;
2004
Abstract
The goal of our experiment is to collect alkali atoms in a magneto-optical trap (MOT) for high-precision spec- troscopy and for the study of parity violation in atomic sys- tems. We are focusing on francium isotopes, which are particularly suitable for these purposes. The production of francium is achieved by sending a 100-MeV 18 O beam from the Tandem-XTU accelerator on a thick gold target. The extraction of Fr+ is enhanced by heating the target to 1200 K and by biasing it at +3 kV. The ions are transported to the magneto-optical trap (MOT) through an 8-m electro- static beam line. The diagnostic systems for monitoring the beam intensity (about 10^5 ions/s) are based on silicon surface- barrier detectors sensitive to the α particles from Fr de- cays. Beams of stable Rb+ can also be used for optimizing the transport and trapping processes. At injection into the MOT cell, the beam is neutralized and released in atomic form by a heated yttrium foil. Details on Fr production, transport and neutralization are presented.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
