Abstract: This invention relates generally to a method of operating an ion trap mass spectrometer to determine the resonant excitation frequencies of trapped ions. This can be achieved by: (1) introducing sample ions into the ion trap volume: (2) adjusting the trapping fields so that parent ions having a mass-to-charge ratio of interest which are to undergo collision induced dissociation (CID) are trapped; (3) applying an excitation voltage of predetermined frequency and amplitude across the end caps of the ion trap; (4) scanning the frequency of the excitation voltage in a first direction and monitoring for ejection of the parent ions; (5) repeating steps (1) through (3) and scanning the frequency of the excitation voltage in an opposite direction and monitoring for ejection of the parent ions; (6) averaging the frequencies at which the ions are ejected; and (7) applying that frequency in a subsequent MS/MS scan to promote CID of the parent ions to form daughter ions.

Abstract: An improved method of mass analyzing a sample in a three-dimensional quadruple ion trap with varying fields is disclosed. The dynamic range and sensitivity of previous methods is increased by controlling the number of sample ions formed in the ion trap to avoid saturation and space charge.

Abstract: A method is disclosed for increasing the dynamic range and sensitivity of a quadrupole ion trap mass spectrometer operating in the chemical ionization mode. Prior to mass analysis, a prescan is performed with the ion trap and the ionization and reaction periods are adjusted to produce enough stored product or analyte ions to generate a good signal-to-noise ratio in the detection of trace amounts of analyte, yet not so many analyte ions that resolution in the mass spectrum is lost. A mass analysis scan is then performed with the ion trap using the ionization and reaction periods predetermined during the prescan.

Abstract: A multiple laser beam system comprises a laser device which is intended to be attached on or near the barrel of a rifle or the like such that triggering of the weapon activates the laser transmitter and results in the laser device producing a plurality of beams which by means of an adjustable diverging lens on the laser device may be defocused to produce an overlapping pattern. The beams are transmitted sequentially by the laser head assembly while timing of the transmission of the beams is controlled by electronic beam encoding logic. When the weapon is fired a mechanical-to-electrical transducer is energized and generates an electrical signal used to trigger the laser firing sequence. Visual indication means are provided to indicate that the laser timing sequence has been initiated. The light beam is detected by a target having a plurality of light sensing detectors. Whereby an indication of the accuracy of the aim of the weapon may be obtained.