Description
In order to demonstrate the feasibility of optical pumping using ISCOOL,
the technique was demonstrated on a bunched \sr beam using the COLLAPS
beamline. The 88Sr beam was passed through the COLLAPS charge exchange
cell and the neutral counts were registered using an SEM. Strontium is
ideal for such a test because the metastable state to which it is pumped
charge exchanges resonantly with sodium vapour, allowing a clear
difference in signals to be seen between the neutral counts for a beam
of ground state ions and a beam of metastable state ions. The results of
this test show that optical pumping can be performed in ISCOOL, and the
magnitude of this effect is derived from the data as a function of
power, wavelength and beam energy. Relevant results with respect to
ISCOOL performance are also presented.