FIRST RESULTS OF THE TUNABLE MONOCHROMATIC GAMMA-RAY SOURCE AT THE GHENT 15 MEV LINAC

By combining a curved crystal spectrometer, operated in Cauchois geometry, with a broad gamma-ray source emitting a continuous energy spectrum, it is possible to obtain gamma-ray beams of which both the bandwidth and the energy can be tuned. The feasibility of such a facility is demonstrated using bremsstrahlung produced by the high intensity electron accelerator of the University of Ghent as a primary source and the former SCK Mol bent crystal spectrometer to select the wanted energies via Bragg diffraction. Applications of the obtained gamma-ray beams, i.e. the direct measurement of the K-edges of heavy elements or the detection of heavy elements in materials, are indicated and illustrated by the first experiments performed with the tunable gamma-ray source.