An open-flow cryogenic cooler for single-crystal diffraction experiments

A simple, low-cost and efficient open-flow cryogenic cooling system has been constructed for crystallographic data collection from flash-cooled protein crystals on the rotation-camera station at the Stanford Synchrotron Radiation Laboratory. A constant temperature of less than 100 K at the crystal position can be maintained for an indefinite period of time. A small heater surrounding the delivery nozzle and another between the sample crystal and the sample support are used to prevent the formation of ice. The system includes an automatic filling capability so that the device can be run unattended for up to approximately one week.