Imaging Optics for the Single Atom Microscope (SAM) for Nuclear Astrophysics

We are developing the technique of optically detecting individual atoms embedded in thin films of cryogenically frozen solids in order to measure low yield nuclear reactions relevant to nuclear astrophysics. Noble gas solids such as frozen neon are an attractive medium because they are optically transparent and provide efficient, pure, stable, & chemically inert confinement for a wide variety of atomic and molecular species. The excitation and emission spectra of atoms embedded in solids can be separated by up to hundreds of nanometers making optical single atom detection feasible. We propose to couple a single atom microscope (SAM) detector to a recoil separator which would minimize the heat load on SAM while allowing for isotope discrimination. This technique has the potential to capture and detect every product atom with near unity efficiency. Because of the additional selectivity provided by resonantly exciting the atomic transitions of the captured product atom, SAM would have a negligible false positive rate which would help loosen the often demanding beam rejection requirements imposed on recoil separators. We will present our study of the dependence of the light collection efficiency of the optical imaging system on a variety of parameters including magnification.