Microcalorimeter array for the measurement of kinetic energies of small particles in space

This paper describes a novel calorimetric measurement method for the in situ measurement of the kinetic energy of micrometer-sized particles in space. An incoming particle hits the detector area with a typical velocity of about 10 km/s and the resulting impact heating of the absorber material is measured by an array of microcalorimeters utilizing a 16 × 16 array of thermopile heat power sensors. Experimental tests with accelerated dust particles as well as with laser pulses have proven the capability of this measurement principle. The detection threshold for heat deposition is about 10 nJ for a gold absorber of 2.8 μm thickness. At the moment, a flight model of the calorimetric particle detector is being developed and will be ready to be launched into space in the near future.