9:00 AM - 9:15 AM
[PPS12-01] Development of ambient-controlled gas levitation system embedded in tube furnace and its application to chondrule formation
Keywords:Chondrule, Gas levitation technique, Crystal growth
The following is a summary of the newly developed equipment. A vertical tube furnace with a double-helical silicon carbide heating element and an alumina core tube (OD 50 mm, ID 42 mm) is used as a heating source device. An alumina inner core tube (OD 32 mm, ID 26 mm) with a carbon nozzle (blowout hole diameter of 1 mm) at the top is inserted into the outer tube. H2+CO2+Ar mixed gas are separately introduced into the both inner and outer core tubes from a gas port at the bottom, and gas flow rates can be controlled by digital mass flow controllers. The inner tube with the nozzle can move up and down by motor-controlled pantograph, and thereby the seamless switching from a sample exchange positon to a maximum temperature position becomes possible. A levitated sample can be in situ observed by a long focal CCD camera thorough a mirror from the top of furnace. Because thermal radiation light around the heating sample prevents the observation at high temperatures, a dichroic filter that cut >500 nm wavelength light and high power blue (460 nm) LED illumination are installed into the observation optics. Currently, using this system, quenched NaAlSi3O8 glass were successfully collected from 1280 degree Celsius. The developed gas levitation system of the present study show that reducing-gas levitation experiments is a powerful technique to simulate the molten-quenched texture of early solar materials.