Electronic impact source
Noble gases analysis by static mass spectrometry Theory and instrumentation

Nier source mass spectrometers, also known as electron impact mass spectrometers, are used to measure the concentrations and isotopic compositions of elements (H ₂ , CO ₂ , N ₂ , noble gases, etc.). They consist of three distinct elements namely, a source to ionize the gases, a magnetic sector to separate the isotopes according to their m/q ratio and several collectors to transform ionic fluxes into measurable electrical currents (figure 1 ).