For long-time diusion experiments shear-cell techniques oer more favourable
terms than the traditional long capillary techniques. Here, we present a further developed
shear-cell that enables the measurement of diusion coecients up to temperatures of 1600 C.
Hence, diusion experiments can be carried out at temperatures not accessible until now by
conventional capillary or shear-cell techniques. The modied shear-cell, which can contain up to
six samples of a total length of 90mm and a diameter of 1.5 mm, is built of 30 shear discs of 3mm
thickness each. It is operated in an isothermal furnace insert which can be accommodated in the
Materials Science Laboratory of the International Space Station. This provides the opportunity
that the shear-cell can be applied to microgravity and to ground-based experiments, respectively.
The heater insert with an overall length of 518mm and a diameter of 210mm consists of four
heating zones with a total power of 3.5 kW. Temperature homogeneity along the graphite sample
compartment is better than 2K at 1600 C. Details of the new design are discussed and results
of rst successfully performed heating and shearing cycles are presente