The invention relates to a miniature magnetic spectrometer with a coaxial structure. This spectrometer, associated with a particle generator, comprises a transformer producing a magnetic field for deflecting the charged particles injected at one end of the spectrometer body. The transformer is provided with a secondary circuit, constituting the spectrometer body, formed by an external conductor in short-circuit with an internal conductor and coaxial to the external conductor. These two conductors define an annular space in which can move the charged particles. Means for detecting the deflected particles, disposed at a second end of the spectrometer body, means for selecting the particles in accordance with their injected angle and a converter element for the particles placed in the annular space level with the first end also being provided.
An improved electro-optical ion detector comprising a channel electron multiplier assembly located at the angled focal plane of the magnetic sector of a scanning mass spectrometer with a twisted fiberoptic window with a means for precisely optically coupling the assembly to the twisted fiberoptic window. Means are provided for precisely spacing the entrance end of said twisted fiberoptic window in the form of a foil of a selected thickness. Also disclosed is a method for making an improved electro-optical ion detector.
A single-slice data acquisition system (DAS) for a CT imaging system is time-multiplexed to measure more than one signal over the DAS standard sampling time interval. In one embodiment, a detector element includes a scintillator and two photodiodes aligned with respective portions of the scintillator. Each photodiode generates a signal based on the scintillator output. The signal from one of the photodiodes is subjected to a time-dependent gain during consecutive sampling intervals. The gain-adjusted signal and the signal from the other photodiode are combined, and the combined signal is processed to obtain an estimate of the z-derivative of the signal. The estimated z-derivative is then used to generate a high quality image.
A magnetic sector for a non-scanning mass spectrometer includes a high permeability yoke with opposing faces to which are attached high energy product magnets and shaped pole pieces separated by a gap so that a high magnetic flux exists in the gap. The high magnetic flux in the gap enables very small surface areas of the pole pices faces forming the gap so that the overall magetic sector volume and weight are reduced.
An ion trap which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10.sup.9 and commercial mass spectrometers requiring 10.sup.4 ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products.
A portable analytical grade mass spectrometer system contained in a single enclosure is disclosed for use in analyzing atmospheric, water, soil, drugs, explosives and other substances and includes a gas chromatograph and a mass analyzer assembly enclosed within a vacuum housing, a vacuum pump, and an on-board computer such that an operator, by means of an attached keyboard, can input data and information, and input a sample to be analyzed, and thereby operate the miniaturized mass spectrometer system.
