Multichannel spectroscopy

Kemnitz, K., Pfeifer, L. and Ainbund, M. R. (1997). Detector for multichannel spectroscopy and fluorescence lifetime imaging on the picosecond timescale. Nucl. Instrum. Meth. Phy. Res. A 387, 86-7. 

Application of laser Raman multichannel spectroscopy to a kinetic investigation in the liquid phase has been reported by Crunelle-Cras and Merlin (1977). A multichannel spectrometer with photoelectric image devices, interfaced with a data aquisition and handling system, permits the study of fast processes, exemplified by the fast oxidation of the sulfite ion by the bromate ion in an acidic medium. 

OMA 2 Multichannel Spectroscopy Equipment Brochure EG G Princeton Applied Research Corporation Princeton, NJ, 1981. Rarasek, F. W. Res./Dev. 1972, 24. 

Table I, shows the spectrometers recently developed by the authors. All are based on the principle of multichannel spectroscopy utilizing image devices as sensors (1). In these spectrometers, a spectrum is scanned rapidly electronically, typically in 10 ms. Spectral data can be readily available ina digitized form, the sensitivity of these image devices is generally better than...

Cytochrome c oxidase for higher organisms contains two haem chromophores at different reduction potentials, a and a, each with an associated copper centre, Cua and Cub respectively. The sequence of reduction of molecular oxygen by fully reduced, membrane-bound cytochrome c oxidase has been deduced > using dual-wavelength multichannel spectroscopy at low temperature. Initial binding of O a is followed by formation of superoxide and oxidation of haem a. Subsequent reactions include internal electron transfer from haem a and Cub with formation of peroxide. Ferricyanide pretreatment oxidizes only haem a and its associated copper and the initial interaction with O2 again produces superoxide and oxidized haem a. ... 

Figure C3.5.3. Schematic diagram of apparatus used for (a) IR pump-probe or vibrational echo spectroscopy by Payer and co-workers [50] and (b) IR-Raman spectroscopy by Dlott and co-workers [39]. Key OPA = optical parametric amplifier PEL = free-electron laser MOD = high speed optical modulator PMT = photomultiplier OMA = optical multichannel analyser.

Figure 8-1. Layout of the experimental scl-up for field-assisted pump-probe spectroscopy. PD photodiode OMA optical multichannel analyzer.

The output from the TAC is an analog signal that is proportional to the time difference between the start and stop pulses. The next step consists of digitizing the TAC output and storing the event in a multichannel analyzer (MCA). After repeating this process many times, a histogram of the arrival times of photons is accumulated in the memory of the MCA. In fluorescence lifetime spectroscopy the histogram usually contains 512-2048 channels... 

The equipment used in gamma spectroscopy includes a detector, a pulse sorter (multichannel analyzer), and associated amplifiers and data readout devices. The detector is normally a sodium iodide (Nal) scintillation counter. Figure 27 shows a block diagram of a gamma spectrometer. 

T. Suto, M. Fukuda, M. Ito, T. Uehara, and M. Mikuni. Multichannel near-infrared spectroscopy in depression and schizophrenia Cognitive brain activation study. Biological Psychiatry, 55 501-511, 2004. 

Structural characterization of the surface metal oxide species was obtained by laser Raman spectroscopy under ambient and dehydrated conditions. The laser Raman spectroscope consists of a Spectra Physics Ar" " laser producing 1-100 mW of power measured at the sample. The scattered radiation was focused into a Spex Triplemate spectrometer coupled to a Princeton Applied Research DMA III optical multichannel analyzer. About 100-200 mg of... 

Barbillat, J. and Da Silva, E., Near infrared Raman spectroscopy with dispersive instruments and multichannel detection, Spectrochim. Acta A, 53, 2411, 1997. 

Brauers, T., M. Hausmann, U. Brandenburger, and H.-P. Dorn, Improvement of Differential Optical Absorption Spectroscopy with a Multichannel Scanning Technique, Appl. Opt., 34, 4472-4479 (1995). 

Figure 11.11—Multichannel detection, a) Multichannel detection with a diode array located in the focal plane. The light beam is diffracted by the concave dispersive system after travelling through the sample. Note the absence of an exit slit b) spectrum of a 1 1 000 solution of benzene in methanol. This spectrum represents a typical spectrum without smoothing and is obtained with commercial photodiodes (note in contrast to mid IR spectroscopy, interferometry followed by Fourier transform has led to few commercial achievements in this area).

Figure 7.36 Diagram of a single photon counting apparatus for time-resolved spectroscopy. L, pulsed light source S, sample P, photodiode F, filter or monochromator D, photomultiplier R, voltage ramp driver G, gate Cj, C comparators M, multichannel analyser...

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