On-Line Nuclear Orientation
Some dilution refrigerators are designed to be placed on-line to a
radioactive beam. Nuclei are implanted into the host lattice which is already
at mK temperature. The nuclei will then relax (reach thermal equilibrium),
taking a characteristic time, tSLR. Provided that tSLR >
T1/2, then the nuclei will orient before decaying so experiments are
The group has access to beams of both proton- and neutron-rich isotopes,
allowing studies on both sides of the valley of stability. At CERN we can
orient the proton-rich products of spallation reactions of a 1 GeV proton beam
on various targets, in the NICOLE refrigerator.
Neutron-rich fission products are studied using the OSIRIS separator in Studsvik, Sweden. In 1995 the group moved the refrigerator from the NSF in Daresbury to there, as part of a successful collaboration with Prof. B. Fogelberg of Uppsala University. Experiments in Studsvik have produced measurements of numerous magnetic moments around the doubly magic 132Sn.