In this thesis transmission of different ions through a drift tube and shutter grid has been measured. Various ions were injected at the same rate at the start of the drift tube. Then, the transmitted currents were measured at the end of the drift tube. The results show that transmission depends linearly on the inverse of the drift time. Factors influencing the drift time, such as pressure, temperature, and electric field, were also investigated and shown to affect the transmission efficiency in a similar manner as the type of ion. A simple model based on kinetics of two parallel processes (loss or transmission) is proposed to explain the results. Since slow-moving ions are lost more often than fast-moving ones, the intensity of ion peaks decreases as drift time increases. This can be easily corrected by transforming the y axis to y× x (i.e. intensity×drift time). It was also shown that the transmission of ions depends negatively on drift length and positively to diameter of drift tube. The transmission through a Bradbury-Nielson type shutter grid was also studied. It was shown that the relative transmission of ions through the shutter grid depends not only on the opening time but also on the nature of ion and the voltage applied to the grid electrodes. The transmission of fast moving ions is higher than that of slow moving ions and, in general, applying a voltage greater than the blocking voltage reduces the transmission. A simple model was proposed to explain the results. Since slow-moving ions are lost in greater numbers than fast-moving ones, the intensity of ion peaks decreases as drift time increases. This can be corrected by multiplying the intensities by a factor of (1 + atd) where a is a small correction factor which depends on the geometry of both the shutter grid and the drift tube and on the opening time.
