The determination of the mean sizes of large He droplets by electron impact induced attenuation

The mean number sizes of large He droplets (N≲105 atoms) created in a free jet expansion are measured by attenuating the droplets by the electrons of a mass spectrometer ionizer. Droplets formed at source temperatures of 6, 12, 15 and 20 K and source pressures from 1 to 100 bar are investigated. The resulting values of mean droplet sizes agree well with previous results obtained by an independent method.