Facilities   Mössbauer furnace for HT emission measurements

Mössbauer Spectroscopy Division, Pedagogical University, Cracow, Poland

  1. 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
  2. Kr-filled proportional detector with iron-free Be window and a single line absorber support - K457Fe(CN)6 x 3H2O absorber is used
  3. iron-free 0.3 mm thick Be window with external interchangeable beam collimator - 20 mm diameter window
  4. water cooling tube - the whole furnace is surrounded by the flowing water sheath - about 1 litre/min.
  5. 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
  6. vacuum tight alumina tube
  7. fine alumina powder thermal insulation
  8. external heating coil made of amorphous kanthal (APM) - about 1 Ohm resistance at ambient temperature
  9. gas outlet / pumping flange
  10. 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).