Region detector

All mass spectrometers have different stages of pumping in order to maintain the analyzer and detector regions under high vacuum, i.e. 10 7 10 8 torr or higher. Depending upon the ionization technique, the inlet system and the ion source must be/... 

DNA samples are introduced into the 96-capillary array. When the samples are separated through the capillaries, the fragments are irradiated with laser hght. A charge coupled device measures the fluorescence and acts as a multichannel detector. The bases are identifled in order in accordance to the time required for them to reach the laser-detector region. 

The ECL reaction can occur at room temperature in aqueous buffered solutions and in the presence of dissolved 02 or other impurities. To provide the electric field for ECL to occur at the detector region, a pair of connecting floating Pt electrodes (50 pm wide, 50 pm apart, and 100 nm thick) has been used. To improve the adhesion of the Pt layer, a Cr underlayer was used. Unfortunately, Cr was corroded in the presence of CL [725]. 

Photo-detector regions are formed in JP-A-1205476 by laser annealing a multi-layer structure of HgTe and CdTe. Radiation which has generated charge carriers between two detector elements will be absorbed in the multi-layer structure thereby reducing cross-talk. 

In JP-A-1233777 the amount of cross-talk is reduced by diffusing mercury into detector regions thereby reducing the acceptor carrier concentration in these regions while the regions in between the detector regions are kept at a high acceptor carrier concentration. 

An HgCdTe layer is epitaxially grown on a first substrate. An adhesive is used to attach the HgCdTe layer to a sapphire substrate, which absorbes infrared radiation. The first substrate is removed and the epitaxially grown HgCdTe layer is shaped by etching to form detector regions 14, which are connected by electrodes 15. Photons which are not absorbed by the detector elements will be absorbed in the sapphire substrate. 

PN-junctions 2 are formed in a substrate 1. An oxide is grown by anodic oxidation over the whole surface of the substrate. A metallic layer 4 is deposited on the anodic oxide. This layer may consist of a first layer which has a good adhesion to the oxide and a second layer which is opaque to infrared radiation. The metallic layer is shaped by photolithography in order to cover only zones surrounding the detector regions. A dielectric layer 5 is deposited covering the whole surface and the photodiodes are connected by metal connections 6. An embodiment with a planar structure is also shown. 

The imager of JP-A-6089991 (Toshiba Corp., Japan, 29.03.94) comprises HgCdTe detector regions which have been grown on a silicon substrate. A method to clean the silicon surface before the HgCdTe regions are grown thereon is disclosed. 

Thereafter, HgCdTe detector regions 13 are grown on the silicon substrate and individual detector elements are connected to the charge transfer device. 

Although the isotope ratios of samples may be compared with high precision, the absolute errors may be quite large, usually of the order of 1.0%. These errors may be attributed to the method of introducing the sample into the mass spectrometer or to discriminating effects within the ion source, analyzer, or detector regions of the instrument (26). 

The third step was to apply the multicomponent analysis to the smoothed data. The basic principles of this analysis are as follows at each point in time, the measured fluorescence signal in each of the four emission channels is assumed to be a superposition of the fluorescence emission from the different amounts of the four dyes present at that moment in the detection region of the gel tube. These measured values at each time point may be considered to be the components of a four-vector in "detector space". We wish to use these values to deduce the components of a second four-vector a in "dye space", whose components are the different amounts of each dye present in the detector region at that moment. This transformation is represented in equation 1. 

However, it is also possible to detect the presence of ions in resonance by measuring the power absorbed from the rf electric field using an amplitude-limited oscillator in the detector region. Such oscillators have been used extensively to detect power absorption in NMR, and detailed discussions of the principles and their applications have appeared elsewhere. ... 

Hence, 10 ions simultaneously absorbing power in the detector region would be expected to give a signal-to-noise ratio of 1/1. Depending upon the drift velocity, this corresponds to a minimum detectable ion current of about 10 A. 

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