Abstract: An ion trap mass spectrometry system adapted for portability and related method includes an ion source for generating ions from a sample to be analyzed, and a resistive drift tube coupled to an output of the ion source for receiving the ions injected therein. The resistive drift tube decelerates the ions to provide cooled ions having a mean translational kinetic energy of less than 5 keV. A miniature ion trap or trap array, such having apertures <1 mm, is coupled to an output of the resistive drift tube for trapping the cooled ions. A spectrometer is coupled to the miniature ion trap for analyzing the cooled ions.

Abstract: An ion trap mass spectrometry system adapted for portability and related method includes an ion source for generating ions from a sample to be analyzed, and a resistive drift tube coupled to an output of the ion source for receiving the ions injected therein. The resistive drift tube decelerates the ions to provide cooled ions having a mean translational kinetic energy of less than 5 keV. A miniature ion trap or trap array, such having apertures <1 mm, is coupled to an output of the resistive drift tube for trapping the cooled ions. A spectrometer is coupled to the miniature ion trap for analyzing the cooled ions.

Abstract: An entrance grid is positioned in the incident beam path of a DC beam positron lifetime spectrometer. The electrical potential difference between the sample and the entrance grid provides simultaneous acceleration of both the primary positrons and the secondary electrons. The result is a reduction in the time spread induced by the energy distribution of the secondary electrons. In addition, the sample, sample holder, entrance grid, and entrance face of the multichannel plate electron detector assembly are made parallel to each other, and are arranged at a tilt angle to the axis of the positron beam to effectively separate the path of the secondary electrons from the path of the incident positrons.

Abstract: An entrance grid is positioned in the incident beam path of a DC beam positron lifetime spectrometer. The difference between the potentials applied to the sample and the entrance grid provides simultaneous acceleration of both the primary positrons and the secondary electrons. The result is a reduction in the time spread induced by variation of the secondary electron energy. The spectrometer also includes a means for path separation of the incoming positrons and the outgoing secondary electrons from the sample in the non-acceleration range. The result is a positron lifetime spectrometer with a wide time range representing exponential decay functions of annihilation radiation intensity, and an improved time resolution. Results to date show that a valid time range of more than 300 nsec, a time resolution of 570 psec, and a signal-to-noise ratio of 3300 have been achieved.