HIGH CAPACITY ION CYCLOTRON RESONANCE CELL
Comprehensive research on stability of amorphous silicon and alloy materials and devices: Annual report, 31 May 1995 - 30 May 1996
BRIEF DESCRIPTION OF THE INVENTION
This invention relates generally to an ion cyclotron resonance (ICR) cell, and more particularly to an ICR cell with large ion storage capacity.
BACKGROUND OF THE INVENTION
Ion cyclotron resonance is well known and has been employed in numerous spectroscopy devices and studies. Generally, these devices store the ions to be analyzed in cells of various configurations which are disposed in a uniform magnetic field.
THE SPECTRUM AND THE TOTAL INTENSITY OF ELECTROMAGNETIC WAVES SCATTERED FROM AN IONIZED GAS IN THERMAL EQUILIBRIUM IN THE PRESENCE OF A STATIC QUASI-UNIFORM MAGNETIC FIELD
Short and long wavelength disturbances of a two-component collisionless plasma,: With polarization parallel to a uniform magnetic field (AGM report)
Experimental determination of eddy-current torques on bodies rotating relative to a uniform magnetic field (NASA technical note)
Pressure dependence of a plasma diffusion across a uniform magnetic field (IPPJ-70)
A Theory of incoherent scattering of radio waves by a plasma in a uniform magnetic field (Report)
Localized ferromagnetic resonance in non-uniform magnetic fields (Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. Thesis. 1976. Elec. E)
Interfacial instability of fluids of arbitrary electrical conductivity in uniform magnetic fields
Structures of Permanent Magnets: Generation of Uniform Fields
Forced MHD turbulence in a uniform external magnetic field (SuDoc NAS 1.26:172576)
Stability of two-fluid wheel flows with an imposed uniform axial magnetic field (NASA technical note)
Generation of uniform fields with permanent magnets: Lectures (TR)
Effect of uniform external pressure and oblique incidence of the solar wind on the terminal shape of the geomagnetic field, (U.S. National Aeronautics and Space Administration. NASA)
Lower hybrid oscillations in multicomponent space plasmas subjected to ion cyclotron waves (SuDoc NAS 1.26:204723)
Gaseous ions in the presence of the uniform magnetic field are constrained to move in circular orbits in a plane perpendicular to the field (cyclotron oscillations). The ions are not constrained in their motion parallel to the field. As a consequence, various cell configurations have been adopted to retain the ions within the cell. For example, the cell may include end plates which have dc voltages applied thereto, or it may be of an open cell design such as described by Beu et. al., "Open trapped ion cell geometries for FT/ICR/MS, Int. J. Mass Spectrom. Ion Processes, 112 (1992), 215-230. Another cell configuration is described in U.S. Pat. No. 5,019,706.
Desorption Mass Spectrometry (Acs Symposium Series)
ESI/MALDI-Fourier-Transform-Ionenzyklotronresonanz-Massenspektrometrie (FT-ICR-MS): Etablierung der Methode und Anwendung in der Analytik kombinatorischer Verbindungskollektionen, Peptide und Proteine
Radio frequency radiation from hypersonic plasmas with impressed oscillating electric fields
Radio Frequency Power in Plasmas: 17th Topical Conference on Radio Frequency Power in Plasmas (AIP Conference Proceedings / Plasma Physics)
High power RF plasma heating and wave propagation near the fundamental and harmonics of the ion cyclotron frequency
The effect of temperature, oblique incidence and poloidal magnetic field on wave propagation, damping and mode conversion in the ion cyclotron resonance frequency domain
CYCLOTRON INSTABILITIES AND ELECTROMAGNETIC EMISSION IN THE ULTRA LOW FREQUENCY AND VERY LOW FREQUENCY RANGES
Radio Frequency Power in Plasmas: Charleston, SC 1991 (AIP Conference Proceedings)
Multi-species test of ion cyclotron resonance heating at high altitudes (SuDoc NAS 1.26:206145)
Spiral ridge cyclotrons with frequency modulation (A.E.R.E. reports;no.G.P.R2069)
Radio Frequency Power Plasmas: 16th Topical Conference on Radio Frequency Power in Plasmas (AIP Conference Proceedings / Plasma Physics)
Studies of electromagnetic ion cyclotron waves using AMPTE/CCE and dynamics explorer final report, period of performance 6/1/91 to 8/31/94 (SuDoc NAS 1.26:196437)
Phase stability in cyclotrons with the fixed frequency field law (A.E.R.E. reports;GP/R2071)
Lower hybrid oscillations in multicomponent space plasmas subjected to ion cyclotron waves (SuDoc NAS 1.26:204723)
Radiofrequency power transfer to ion-cyclotron waves in a collision-free magnetoplasma (NASA technical note)
A BATSE investigation of radiation belt electrons precipated by VLV waves final report (SuDoc NAS 1.26:189394)
The frequency of the circular motion is directly dependent upon the charge-to-mass ratio of the ions and the strength of the magnetic field. When orbiting ions trapped within the cell are subjected to an oscillating electric field, disposed at right angles to the magnetic field, the ions having a cyclotron frequency equal to the frequency of the oscillating electric field are accelerated to increasingly larger orbital radii and higher kinetic energy. Because only the resonant ions absorb energy from the oscillating field, they are distinguished from the non-resonant ions upon which the oscillating electric field has a substantially negligible effect. The oscillating ions are detected by separate electrodes which have image current induced therein by the oscillating ions. In another example, the cell does not include separate detection electrodes, and is operated in a switched mode. A twoelectrode ion trap is described by Marto, et al., "A TwoElectrode Ion Trap for Fourier Transform Ion Cyclotron Resonance Mass Spectrometry", Int. J. Mass Spectrom. Ion Processes, 137 (1994), 9-30.
Electron Beam Ion Sources and Traps and Their Applications: 8th International Symposium EBIS/T 2000, Upton, New York, 5-8 November 2000 (AIP Conference Proceedings)
Identification of Essential Oils by Ion trap Mass Spectroscopy
SOME IONOSPHERIC MEASUREMENTS WITH SATELLITE-BORNE ION TRAPS
The Arccos and Lommel Diffraction Formulations: An Approximate Fourier Transform Pair Leading to A Unified Theory of Spatially Averaged Diffraction Corrections for Ultrasonic Piston Transducers Operating in Pulsed Mode
Generally, the ions are excited by a pulsed wave form having multiple frequencies whereby ions of different masses undergo ion cyclotron resonance. Comisarow and Marshall in U.S. Pat. No. 3,937,955 describes the operation of an ICR cell excited with waveforms having multiple frequencies in what is known as a Fourier transform mode (FT-ICR). It has been recently demonstrated that one of the primary limitations to obtaining accurate mass measurement for FT-ICR is space charge-induced shifts of the cyclotron frequency. These shifts can be minimized by having a reproducible number of ions during each scan (Winger, et al., "High Throughput, High Speed, Automated Accurate Mass LC-FT/MS Analysis", Proc. 46th ASMS (1998), p. 516).
Other FT-ICR systems are less sensitive to space charge induced shifts and therefore produce more reliable mass accuracy data. For example, the infinity cell (Caravatti et al., "The Infinity Cell: a new Trapped-ion Cell With Radiofrequency Covered Trapping Electrodes for Fourier Transform Ion Cyclotron Resonance Mass Spectrometry", Org. Mass Spectrom., 26 (1991), 514-518) (Allemann et al., "Ion
Fourier Transform Mass Spectrometry: Evolution, Innovation, and Application (Acs Symposium Series)
Fourier transform ion cyclotron resonance mass spectrometry as a probe of chiral recognition (Technical report)
Cyclotron Resonance Spectrometer", U.S. Pat. No. 5,019, 706), which uses a linearized dipolar field which allows a greater ion excitation radius and the use of "side-kick" injection (Caravatti, Pablo, "Method and apparatus for the
Instrumental Effects in Homodyne Electron Paramagnetic Resonance Spectrometers (Ellis Horwood Series in Analytical Chemistry)
Kinetic Energy Storage: Theory and Practice of Advanced Flywheel Systems
5 accumulation of ions in a trap of an ion cyclotron resonance spectrometer, by transferring the kinetic energy of the motion parallel to the magnetic field into direction perpendicular to the magnetic field", U.S. Pat. No. 4,924,089), which gives the ions an initial non-zero magnetron radius.
Negative ions and the magnetron
10 Both of these features contribute to lower ion density and thus a reduced sensitivity to space charge-induced frequency shifts.
International telecommunications and international law: The regulation of the radio spectrum
Spectroscopy: Atomic Absorption Spectroscopy, Electromagnetic Spectroscopy, Beer-lambert Law, Fluorescence, Energy Level, Frequency Spectrum
The primary drawback to a non-zero initial magnetron radius is that the acquired signal will contain significant
15 harmonic content and other modulations of the fundamental signal (Chen et al., "An off-center cubic ion trap for Fourier transform ion cyclotron resonance mass Spectrometry", Int. J. Mass Spectrom. Ion Processes, 133 (1994), 29-38). One method which allows the formation of an off-axis ion cloud
20 without the observation of higher-order harmonics is the use of a two-electrode trap such as described by Marto et. al., "A Two-Electrode Ion Trap for Fourier Transform Ion Cyclotron Resonance Mass Spectrometry", Int. J. Mass Spectrom. Ion Processes, 137 (1994), 9-30. This trap has been shown
25 to be an order of magnitude less sensitive to space charge shifts than a standard cubic trap. The primary disadvantage of the two-electrode trap is the severe axial ejection caused by the parametric excitation and significant axial fields.
Frequency and Severity of Medical Malpractice Claims (R-2870)
New Evidence on the Frequency and Severity of Medical Malpractice Claims
Theft from afar: hacking into RFID.(radio frequency identification device): An article from: Security Management
Primary Marking's eTWIST evidence tracking system gains traction with law enforcement.(CONTRACTS): An article from: RFID (Radio Frequency Identification) Newsletter
The selection of cases by introductory business law book writers: An analysis of the frequency with which particular cases are chosen by introductory business law book writers
Phase stability in cyclotrons with the fixed frequency field law (A.E.R.E. reports;GP/R2071)
