Performance of a Prototype Single Atom Microscope for Nuclear Astrophysics*

The Single Atom Microscope is a novel detector that is under development for measuring small cross section nuclear reactions that are influential in nucleosynthesis. Utilizing inverse kinematics, the product atoms of the nuclear reaction are captured in a thin solid noble gas film prepared on a transparent sapphire substrate under ultra-high vacuum and at cryogenic temperatures. After resonant laser excitation of the captured atoms, the emitted fluorescence light is optically imaged onto a CCD camera, and the product atoms are counted individually. A Prototype Single Atom Microscope has been assembled, and we have developed a semi-automated film growth procedure for depositing 100 micron thick solid noble gas films of high optical quality. Film uniformity, and long term white light transmission have been studied for various film deposition and maintenance temperatures.