Primary ion source of mass spectrometers for the study of the secondary ion mass spectra

An air-cooled ion source construction is described, whose components can stand temperature of 450 deg C and do not release much gas at this temperature. In optimum conditions, the source performance parameters are: anode power, 60-70 W, magnet coil generates a field of 600 G, operating casing temperature, 60-70 deg C, the resultant argon beam has a density of (4-7)x10-3 A/cm2. The gap voltage is limited by the electrical strength of the insulator to a value of 15 kV. The beam gap and single lens electrode geometries ensure beam crossover at about 200 from the edge of the single lens. The ion channel emission diameter d is determined from d/√Ssub(H)=6.7x10-4, where Ssub(H) is pumping rate capacity of the pump, cm/s. at the gas pressure in the beam formation zone. Sources of this type may be used underneath the conductor of a constant-potential accelerator in cases where beams of high flux density are required