Performance of a microsphere plate electron multiplier in APFIM applications

The microsphere plate (MSP) is a recently introduced electron multiplier, that is comparable in principle of operation to the well-known microchannel plate. The performance of a MSP detector has been evaluated for field ion imaging and single atom detection in time-of-flight atom probe mass spectrometry. The image performance of a MSP is not sufficient for obtaining high-quality field ion images, due to the lack of spatial resolution as well as the granularity observed in the images. Gain, pulse height resolution, and temporal resolution obtained from one double thickness MSP are sufficient for use in a time-of-flight single atom sensitivity detector. The detection efficiency was estimated to be ∼42% for ions in the energy range between 10 and 40 keV. The operation of the MSP detector was successfully demonstrated in a typical atom probe application.