Abstract
A new type of radio frequency quadrupole mass spectrometer is proposed and some theoretical considerations for making the mass spectrometer are given. New points of this mass spectrometer are: (a) A quadrupole electric field is produced with ac voltage only, without any dc voltage. (b) The 2nd-order stable region in the quadrupole field is used for ion transmission. The results obtained from the numerical calculation of ion trajectories in the quadrupole field are as follows: (a) The resolving power is found to be about 150. (b) The permissible aparture size is smaller than that of conventional mass spectrometer with ac and dc components. (c) The effect of fringing field is, however, considerably greater than that of the conventional one. (d) The number of rf cycles during which an ion must remain in the field is about 8 times smaller than that of the conventional one having the same resolving power. (e) It can be operated at lower ac voltage of lower radio frequency.
