91ÅÝܽ

Synopsis

An experiment on Collinear Fast Beam Laser Spectroscopy (CFBS) of ^201,205,207At was developed and performed at ISAC, TRIUMF. A successful CFBS experiment would yield Doppler-free hyperfine structures (HFS) in astatine. HFS in astatine have been previously measured, but with limited resolution, so that the measured HFS were unresolved. A new optical detection system has been designed and characterized to enable the measurement of astatine fluorescence with CFBS. The efficiency of the design, accounting for geometry and optical transmission losses, is simulated at 3.9%. Using apertures and black anodized foil, laser scatter background is reduced in the optical detection system. CFBS was performed on astatine, and laser scatter is measured at a magnitude of 100 s^-1 with 50 µW of laser power. Although the astatine beam intensity was below the optical detection limit, the optical detection system was further characterized in preparation for a follow-up CFBS experiment on astatine.