Definition of Microprobe

A microprobe is an instrument that applies a stable and well-focused beam of charged particles (electrons or ions) to a sample. Scientists use this beam of charged particles to determine the elemental composition of solid materials (minerals, glasses, metals). The chemical composition of the target can be found from the elemental data extracted through emitted X-rays (in the case where the primary beam consists of charged electrons) or measurement of an emitted secondary beam of material sputtered from the target (in the case where the primary beam consists of charged ions). When the primary beam consists of accelerated electrons, the probe is termed an electron microprobe, when the primary beam consists of accelerated ions, the term Ion Microprobe is used. An Ion Microprobe makes a small portion of the material into a plasma; the analysis is done by the same basic techniques as the ones used in mass spectrometry.