A design for a compact time-of-flight mass spectrometer

The design of a prototype, compact time-of-flight (TOF) mass spectrometer is described. The system primarily consists of an ion acceleration∕focusing∕steering assembly (AFSA), an 8 cm field-free region, a 4 cm dual-stage reflectron, and a miniature microchannel plate detector. Consequently, the resulting flight length of the system is 12 cm. The system has been designed with the capability to sample directly from atmosphere at ambient pressures. This is accomplished through the use of an electrodynamic ion funnel, housed in an intermediate-vacuum chamber that is coupled to the inlet of the TOF chamber. TOF spectra were obtained using noble gases (Ar, Kr, and Xe) as test chemicals. These measured flight times were used to probe the performance of the instrument. A temporal resolution (t(flight)∕Δt) of approximately 125, acquired using (129)Xe(+), has been measured for the system.