Cryogenic Cooling Stage for Multi-modal Chemical Imaging

Professor Alex Laskin had a need to miniaturize a cooling stage to be used for EM experiments with Raman and fluorescence microscopes. The original stage was about 75mm tall and needed to be smaller than 20mm in order to fit under a standard microscope. The head is built like a sandwich and contains a total of 5 layers: base for heater and temperature measurement, sample stage, stage for gas flow, quartz window holder and top plate.  The whole stage needs to be vacuum tight. The system is cooled by liquid nitrogen flow, the temperature is controlled by a high precision temperature controller (cryo-con 26C) with RTD feedback. The temperature needs to be stable within 0.01°C. A fast camera takes pictures of crystal growth within the experimental chamber. The system was designed and assembled by Amy Facility members, the parts were built by the machine shop.

A LabVIEW program to manage the temperature controller and the camera was written by Mike Everly. Readouts for gas flow and hygrometer readings were also included in the data file.