Diode detector

In Chapter 5.4, optical ultraviolet radiation sensors are described, including UV-enhanced silicon-based pn diodes, detectors made from other wide band gap materials in crystalline or polycrystalline form, the latter being a new, less costly alternative. Other domestic applications are personal UV exposure dosimetry, surveillance of sun beds, flame scanning in gas and oil burners, fire alarm monitors and water sterilization equipment surveillance. 

The ability to make ever smaller solid-state devices by improved lithography techniques has led to the development of so-called beam lead Schottky-barrier diode detectors and mixers in which diodes are fabricated by the same techniques used to make integrated circuits, and for this reason, they can be included in these circuits. Figure 7 shows such a beam-lead detector/mixer made by Virginia Diodes of Charlottesville, VA [15]. This same configuration is used in fabricating the varactor devices used for frequency multiplication discussed in the preceding section. 

In EDXRF the secondary X-ray emitted by the excited atom is considered to be a particle (an X-ray photon) whose energy is characteristic of the atom whence it came. The major development which has facilitated this technique is the solid state semiconductor diode detector. An EDXRF system consists of a solid state device which provides an electronic output that is... 

T. A. Louis, G. Ripamonti and A. Lacaita, Photoluminescence lifetime microscope spectrometer based on time-correlated single-photon counting with an avalanche diode detector, Rev. Sci Instrum. 61, 11-22(1990). 

In principle, therefore, FFC relaxometry could employ - and often does so - a number of detector types such as phase detectors, diode detectors, square detectors, modulus detectors, envelope detectors, SQUID detectors, etc. 

There are various approaches to the data-reduction task. An often used one consists of computing the modulus of the complex phase-detector signal. This removes all offset imperfections as well as any receiver phase misad-justment, bringing us theoretically to what we would have by summing the outputs of two independent, ideal diode detectors. In this case, however, the original signals are still available and can be used to check various aspects of data quality, carry out additional corrections (such as removal of noise-rectification artifacts), or submitted to alternative evaluation algorithms. 

IFS66-FRA-106 FT-Raman spectrometer equipped with a liquid-Nj cooled Ge-diode detector. Samples were in small glass capillary tubes at 23°C. The spectra were calculated by averaging -200 scans followed by apodization and fast-Fourier-transformation to obtain a resolution of -2 cm and a precision better than 1 cm . The spectra were not corrected for (small) infensity changes in detector response versus wavelength. 

For a broadband r.f. amplifier of bandwidth Afi sending a signal to a square-law diode detector and thence to a low-frequency video amplifier of bandwidth A/j the noise power is (Dicke 1946 Robinson 1974)... 

Throughout this section all V are functions of z they have been printed bold in (8.20) to emphasize that they contain phase information. They are summed as complex quantities, i.e. with respect to both their amplitude and phase. But in the usual experimental implementation, where V is measured through a diode detector, the phase information of V is not available. Therefore, if the system has been calibrated to give square law detection, the measured signal may be represented as... 

The light-weight Elva-X energy dispersive XRF spectrometer employed for this study has an air-cooled rhodium target anode X-ray tube with 140 micron Be window and a thermoelectrically cooled Si-PIN diode detector. The detector... 

If a emitters are separated and collected by fraction collection, the preparation of very thin counting sources in a consistent matrix is required to obtain high-energy resolution. These are placed in close proximity to a diode detector, typically in vacuum. Nevertheless, a energy peak overlap can still occur for various combinations of radionuclides if they are not chemically separated, for example, M1AmPPu and 237Np/234U. 

Egorov, O. B., Addleman, R. S., O Hara, M. J., Marks, T., and Grate, J. W., Direct measurement of alpha emitters in liquids using passivated ion implanted planar silicon (PIPS) diode detectors, Nucl. Instrum. Methods Phys. Res., Sect. A, 537, 600-609, 2005. 

Figure 1. A Rutherford backscattering spectrum for a thin (40/ig/cm2) MoSt sputter-deposited film. Conditions 4He ions normally incident at 3.0 MeV, and scattered ions detected at a 135° angle by a surface-barrier diode detector. Note the scale factor for other than the Mo peak and the Si substrate. The sample layer configuration is indicated at the upper left.

Figure 7. A spectrum of particles resulting from nuclear reactions and scattering from a thick Si3Ni standard. Conditions 2H ions normally incident at an energy of 1.41 MeV, and resulting reaction particles detected at a 165° angle by a surface-barrier diode detector. The particle group marked a, is from the 14N(d,a)i2C reaction and is used to profile N in samples.

In the category of electronic thermometers, the thermocouples (TCs), resistance temperature detectors (RTDs), thermistors, integrated circuitry (IC), and radiation thermometers will be discussed in separate subsections. The IC and diode detectors will be discussed in connection with cryogenic thermometry. Their characteristics are shown in Figure 3.161. 

Rapid raster-scanned CW imaging systems have also been developed. In one such implementation, a 0.2 THz Gunn diode source and Schottky diode detector [93] could raster-scan an object at a 512 pixels per second acquisition rate. The advantages of pulsed THz TDS compared to CW imaging is that broad spectral information (0.1-3 THz) can... 

The SPR, as well as the SPFS and the SPDS set-ups are built in the Kretschmann-Raether configuration depicted in Fig. 5. A detailed description can be found in a more specific publication [25]. Briefly, the modulated and polarized beam of a laser is reflected off the base of the coupling prism and fed into a photo-diode detector. The prism/sample and the photo-detector are mounted on two co-axial goniometers, respectively, allowing for an independent tuning of the respective angular positions. 

The diffraction experiments can be performed on the same Kretschmann SPR set-up (cf. Fig. 6). To resolve the diffraction orders, the angular acceptance of the photo-diode detector is defined by a 1 mm slit to be At 0.08°. The coaxial goniometers enable an independent tuning of the incident angle of the laser and/or the detection angle. Both motors rotate in a 0/20 fashion for the usual SPR angular scans, whereas only the detector motor rotates when performing diffraction scans. 

Effluent solution from the ion exchange column is passed through an in-line alpha-detector which activates a count-rate meter and recorder outside the cell. Inside the detector/ the liquid flow is passed adjacent to a Mylar film-covered window/ which separates the liquid from the silicon diode detector. 

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