Double sublimation system to deposit molecules from solid organic compounds onto a cryogenic substrate: Thymine on solid argon

摘要

We report on the design, operation, and performance of a double sublimation system for the deposition of a submonolayer up to a few layers of a low-vapor pressure molecular solid compound onto a cryogenic substrate. The system consists of a primary oven (i.e., crucible type) to degas and first sublimate the compound onto the tip of a secondary oven (i.e., finger type), which is then used to transport the purified compound inside an analysis chamber and sublimate it just in front of the cryogenic substrate. The latter is kept at exactly the same position all the time, which is essential for experiments sensitive to target position. Besides, the negligible radiant heat transfer from the tip of the secondary oven allows operation in the presence of a cryogenic substrate consisting of an inert gas solid. The overall performance of the system is studied by EEL spectroscopy for thymine deposited onto a multilayer film of Ar used as an inert cryogenic substrate.