CO2 Laser

A fully-automated 10 watt Synrad CO₂ laser system is available for single crystal fusion of sanidine, anorthoclase, plagioclase,  and other silicate minerals. Single ca. 300-600 micron diameter crystals are placed in the 1 mm diameter wells of a 121-hole, stainless steel laser tray.  Zaber actuators move the CO₂ laser above the rigidly mounted laser chamber. Feedback during lasing is provided by the intensity response imaged by a firewire infrared Guppy CCD camera.  The laser beam is focused through a Cleartran window (50 mm viewable aperature) to attain a 150 micron spot at the sample.  UHV conditions are acheived within the laser cell by maintaining the intermediate volume of a custom Helicoflex double vacuum gasket at < 1 Torr.  An intermediate height KBr window mounted on a removable cylindrical stainless steel standoff prevents films of sublimed material from coating the Cleartran window or the walls of the laser cell. It takes about 24 hours to complete analysis of a tray with an additional 5 hours required for sample bakeout and detector calibration.