A new tool for MeV astrophysics – the tunable Laue-lens

A novel telescope for astronomy in the MeV energy band is presented. The concept builds on Bragg diffraction in crystals. Such ‘Laue-lenses’ have been discussed in the past, but so far a design with good sensitivity over a wide energy range seemed out of reach. In the first sections of this paper we shall show that if we find ways to adjust, in orbit, the individual tilt of all the crystals in the lens this would allow one single lens to cover with excellent efficiency the full range of energies from 200 keV to 2.5 MeV in a few observation steps.

We also show, that lenses with double crystal layers may significantly increase the photon collection. In the subsequent sections we describe our proposed lens design in more detail and present our first prototype tilt adjustment pedestal for use with the individual lens facets.