Molecular Physics seminar

Measuring lifetimes of metastable states in negatively charged ions stored in DESIREE

by Erik Bäckström (Atomic Physics Department)

Europe/Stockholm
FA31

FA31

Description
Two weeks ago, Henning gave us an introduction to different electrostatic storage ring projects around the world. In this talk, one of thefirst single ring experiments performed at DESIREE will be presented. The cryogenically cooled storage ring offers an extremely good vacuum in the 10pm14 mbar range. This in turn, allows ion beams to be stored at new time scales up to hours. Thus time-resolved measurement of long-lived metastable state populations can be performed. S- has an excited 2P1/2 level with a predicted lifetime of around 7 minutes. The decay of the metastable state population is actively probed by state selective neutralization by a laser as a function of time. We can now report a value of tau sp = 503 pm 54 seconds for the lifetime of this state which corresponds to 8:38 pm 0:90 minutes.