The GRAFIK detectors (Gamma Ray Annulus For Inverse Kinematics) provide extremely high solid-angle coverage and exploit the forward-focusing that is a characteristic of inverse kinematics reactions. There are two of these detectors, designed at Brookhaven National Laboratory and WNSL, each of which is briefly described below.
One of the GRAFIK detectors is a 3" by 3" NaI(Tl) detector with a central bore hole. A target can be placed within the hole, and the detector then provides 90% coverage of 4pi and an absolute photo peak efficiency (at 300 keV) of 40%. B(E2) values can then be obtained from measured cross-sections.
The other is a linear array of semi-annular NAI detectors which is placed a along the beam tube, downstream of the target position. It is then possible to measure B(E2) values following the Coulomb excitation of levels with lifetimes of the order of a few ns, where the decay occurs in flight.
These detectors are mainly used as part of the program in radioactive beam experiments. Coulomb excitation of 132,134Te was measured recently using GRAFIK at the Holifield Radioactive Ion Beam Facility of Oak Ridge National Laboratory. Results were presented at the Yale Workshop 2001 and the Fall APS meeting in Hawaii.
For more information, contact Charles Barton charles.barton@yale.edu or Victor Zamfir zamfir@galileo.physics.yale.edu