A stigmatic, second-order, double-focusing mass spectrometer

• Published in: International journal of mass spectrometry and ion physics 1978, Vol.26 (1), p.77-90
• Main Authors: Taya, Shunroku, Tsuyama, Hitoshi, Kanomata, Ichiro, Noda, Tamotsu, Matsuda, Hisashi
• Format: Article
• Language: English
• ISSN: 0020-7381; 1873-3034
• DOI: 10.1016/0020-7381(78)80006-0

A double-focusing mass spectrometer of second order was constructed and the focusing property was examined. The ion optical system was determined by computer calculations in order to correct all second-order image aberrations. In the calculations the influences of the fringing field were taken into account. This ion optical system has velocity focusing, radial focusing and axial focusing properties. The instrument is composed of an electric toroidal sector ( r e = 212 mm, φ e = 85.2°, c = 0.5, ρ′ = −106 mm), and a uniform magnetic sector of non-zero entrance and exit angles ( r m = 200 mm, φ m = 90°, ϵ′ = 30°, ϵ″ = −10°). In experimental results, a maximum resolving power of 83 000 at 10% valley separation, and a total transmission of 43% were obtained. Axial focusing action and correction of the crescent shape resulting from second-order aberrations were observed from the shape of spectral lines taken on photographic plates.