γ-Ray lenses - taking a deeper look at sites of nucleosynthesis

摘要

Focusing of γ-rays in the nuclear-line energy regime is a feasible and promising approach for high-sensitivity γ-ray (line) studies of individual sources. This approach combines two unique advantages over "traditional" instrumentation for γ-ray astronomy: arcminute resolutions and a decoupling of collection and detection areas, with the corresponding potential for increased sensitivity. Laue Lenses use diffraction on lattice planes in the volume of a crystal to concentrate photons. Suitable crystals for MeV lenses exist, and lenses with > 100 keV band passes and ～arcmin fields-of-view are feasible today. Fresnel phase shift lenses present another, longer-term possibility for γ-ray focusing. The current status of instrumentation development, lens missions under consideration, and some of the nuclear astrophysics observations such instruments could enable are described.