A high-performance mass spectrometer for very small size

A small bench-top mass spectrometer of the double-focusing type is designed and constructed. The sector magnet of the instrument is very compact due to the small deflection angle (27.8°) and its weight is only less than 30 kg though the magnet radius is 15 cm and the magnetic field is 1.52 T. The field arrangement of QQQHQCQ (Q: Quadrupole lens, H: Homogeneous magnetic sector, C: Cylindrical electric sector) is adopted to achieve high performance. A mass resolution of 5000 can be obtained with an entrance slit of 84 μm.