Abstract: A mass spectrometry method in which an improved field comprising two or more trapping fields having substantially identical spatial form is established and at least one parameter of the improved field is changed to excite selected trapped ions sequentially for detection. The changing improved field (preferably with a supplemental field superimposed therewith) can sequentially eject selected ones of the trapped ions from the improved field for detection. An improved field comprising two quadrupole trapping fields can be established in a region defined by the ring and end electrodes of a three-dimensional quadrupole ion trap, and the amplitude of an RF (and/or DC) component (and/or the frequency of the RF component) of one or both trapping fields can be changed to sequentially excite trapped ions.

Abstract: A method and apparatus for inter-round mixing in iterated block substitution systems is disclosed. The method involves optimizing inter-round mixing so that each sub-block of data affects each other in the same way. This is accomplished by applying a quick trickle permutation or a quasi quick trickle permutation to blocks of data allocated to n individual substitution boxes.

Abstract: A method for generating a filtered noise signal, which includes the steps of generating a broadband signal having optimized (reduced or minimized) dynamic range, and filtering the broadband signal in a notch filter to generate a broadband signal whose frequency-amplitude spectrum has one or more notches (the "filtered noise" signal). In preferred embodiments, the filtered noise signal is a voltage signal suitable for application to an ion trap during a mass spectrometry operation. The invention enables rapid generation of different filtered noise signals (for use in different mass spectrometry experiments) by filtering a single, optimized broadband signal using a set of different notch filters, each having a simple, easily implementable design.

Abstract: A mass spectrometry method in which an improved field comprising two or more trapping fields having substantially identical spatial form is established and at least one parameter of the improved field is changed to excite selected trapped ions sequentially for detection. The changing improved field (preferably with a supplemental field superimposed therewith) can sequentially eject selected ones of the trapped ions from the improved field for detection. An improved field comprising two quadrupole trapping fields can be established in a region defined by the ring and end electrodes of a three-dimensional quadrupole ion trap, and the amplitude of an RF (and/or DC) component (and/or the frequency of the RF component) of one or both trapping fields can be changed to sequentially excite trapped ions.

Abstract: A mass spectrometry method in which one or more high power supplemental AC voltage signals and one or more low power supplemental AC voltage signals are applied to an ion trap. The frequency of each supplemental AC voltage is selected to match a resonance frequency of an ion having a desired mass-to-charge ratio. The low power supplemental voltage signals are applied for the purpose of dissociating specific ions (i.e., parent ions) within the trap, and the high power supplemental voltage signals are applied to resonate products of the dissociation process (i.e., daughter ions) so that they can be detected. In one class of embodiments, the high power voltage signals resonate daughter ions out from the trap for detection by an external detector.

Abstract: A mass spectrometry method in which an improved field comprising two or more trapping fields having substantially identical spatial form is established and at least one parameter of the improved field is changed to excite selected trapped ions sequentially for detection. The changing improved field (preferably with a supplemental field superimposed therewith) can sequentially eject selected ones of the trapped ions from the improved field for detection. An improved field comprising two quadrupole trapping fields can be established in a region defined by the ring and end electrodes of a three-dimensional quadrupole ion trap, and the amplitude of an RF (and/or DC) component (and/or the frequency of the RF component) of one or both trapping fields can be changed to sequentially excite trapped ions.

Abstract: A stackable connector for connecting the conductors of stacked substrates such as printed circuit boards is provided. The connector includes an elongated connector body having a plurality of electrical contacts allowing electrical signals to be passed between the stacked substrates. The connector also includes a plurality of threaded studs and non-conductive nuts allowing the connector body to be securely fastened between the stacked substrates without creating unwanted electrical connections between or within the stacked substrates. The connector also functions as a means for positioning or locating adjacent substrates.

Abstract: A low profile compression electrical connector, for establishing an electrical pathway between two electrical components, includes an insert and a housing. A plurality of connector arms are mounted on a base of the insert, and each connector arm has a first end and a second end. The ends are sufficiently deflectable to allow the connector to fit into a very small space. The housing of the electrical connector is formed with an aperture for receiving and stationarily orienting the base of the insert with respect to the housing. Also, clamps mounted on the housing can be used to hold first and second electrical components, such as printed circuit boards, against the housing and in contact with the ends of the connector arms. Upon engagement of the electrical components with the housing, the ends of the connector arms urge against the electrical components to establish an electrical pathway through the connector arm from the first electrical component to the second electrical component.

Abstract: A mass spectrometry method in which an improved field comprising two or more trapping fields having substantially identical spatial form is established and at least one parameter of the improved field is changed to excite selected trapped ions sequentially for detection. The changing improved field (preferably with a supplemental field superimposed therewith) can sequentially eject selected ones of the trapped ions from the improved field for detection. An improved field comprising two quadrupole trapping fields can be established in a region defined by the ring and end electrodes of a three-dimensional quadrupole ion trap, and the amplitude of an RF (and/or DC) component (and/or the frequency of the RF component) of one or both trapping fields can be changed to sequentially excite trapped ions.