COMBINED TIME-OF-FLIGHT AND MASS-SPECTROSCOPY FOR DETERMINATION OF THE TEMPERATURE OF UNDERCOOLED MELTS

Determination of the temperature of electromagnetically undercooled me lts processed in a high vacuum by optical pyrometry is very limited ow ing to contamination of the optical viewing ports into the processing chamber. A new method for non-contacting, non-optical temperature meas urement was investigated with respect to its feasibility. Here, the en ergy distribution of the evaporating particles, which is of Maxwell-Bo ltzmann type, is determined by measuring the particle velocity distrib ution with the help of a time of flight (TOF) process and the particle masses with a quadrupole mass spectrometer. The first experimental re sults for a solid MnBi alloy agree well with theoretical predictions f itted to simultaneously determined thermocouple readings.