Mössbauer furnace for HT emission measurements
Mössbauer Spectroscopy Division, Pedagogical University, Cracow, Poland
- high precision transducer with the positioning device and Michelson-Morley optical interferometer equipped with the miniature He-Ne laser for the velocity calibration on-line
- Kr-filled proportional detector with iron-free Be window and a single line absorber support
- K457Fe(CN)6 x 3H2O absorber is used
- iron-free 0.3 mm thick Be window with external interchangeable beam collimator - 20 mm diameter window
- water cooling tube - the whole furnace is surrounded by the flowing water sheath - about 1 litre/min.
- source (sample) table on a single axis goniometer head - a goniometer rotation axis is perpendicular to the furnace axis and the table plane could be rotated by about 40o from the orientation perpendicular to the furnace axis each way - the rotation angle could be set in situ with the precision of about 1o
- vacuum tight alumina tube
- fine alumina powder thermal insulation
- external heating coil made of amorphous kanthal (APM) - about 1 Ohm resistance at ambient temperature
- gas outlet / pumping flange
- goniometer driving shaft, thermocouple leads and gas inlet
High temperature part of the goniometer is made entirely of the high purity alumina. Pt-Pt(10%Rh) thermocouple is used to measure the temperature, and the sample is loaded into platinum boat mounted on the goniometer head. Sample dimensions are limited to about 5 mm perpendicular to the goniometer rotation axis and about 10 mm along the above axis.
A gas flow system allows to work either under medium vacuum (about 10-7 Torr) or under gas flow at a pressure close to ambient. One can use either pure hydrogen, a mixture of hydrogen and helium, a mixture of oxygen and helium or pure oxygen.
Inner part of the high temperature zone contains except sample and protective atmosphere alumina, platinum and rhodium. Sample - window distance amounts to about 135 mm.
A sample temperature could be set within the range 30 - 1300oC with the 1oC precision. A power consumption amounts to about 350 W at 1300oC.
November 2000. Please send comments to Krzysztof Ruebenbauer. Back to Facilities.
Background: aerial view of the Nazca Desert, Peru; 600 m altitude above the desert floor (photo: A. Ruebenbauer).