PIN detector

Solid-state detectors based on silicon- or germanium-diodes possess better resolution than gas counters, particularly when cooled with liquid nitrogen, but they allow only very low count rates. PIN diodes have also recently become available and have been developed for the instruments used in the examination of Martian soils (Sects. 3.3 and 8.3). A very recent development is the so-called silicon-drift detector (SDD), which has very high energy resolution (up to ca. 130 eV) and large sensitive detection area (up to ca. 1 cm ). The SNR is improved by an order of magnitude compared to Si-PIN detectors. Silicon drift detectors may also be used in X-ray florescence spectroscopy, even in direct combination with Mossbauer spectroscopy (see Sects. 3.3 and 8.3). 

Fig. 3.15 Left External view of the MIMOS II sensor head (SH) with pyramid structure and contact ring assembly In front of the Instrument detector system. The diameter of the one Euro coin is 23 mm the outer diameter of the contact-ring is 30 mm, the inner diameter is 16 mm defining the field of view of the Instrument. Right. Mimos II SH (without contact plate assembly) with dust cover taken off to show the SH Interior. At the front, the end of the cylindrical collimator (with 4.5 mm diameter bore hole) Is surrounded by the four SI-PIN detectors that detect the radiation re-emltted by the sample. The metal case of the upper detector is opened to show its associated electronics. The electronics for all four detectors Is the same. The Mossbauer drive is inside (in the center) of this arrangement (see also Fig. 3.16), and the reference channel is located on the back side In the metal box shown In the photograph...

Fig. 3.25 Left signal-to-noise ratio (SNR) of the Mbssbauer spectra of a basalt taken with MIMOS II (full SI-PIN detector system black data-points) and MIMOS IIA (1/4 of full SDD system red data-points) respectively. Right XRF spectra of low Z elements measured with MIMOS IIA (SDDs) at —20°C. The Compton scattered 14.4 keV line (at 13.8 keV) and the resonant 14.4 keV Mossbauer line are well separated...

Fig. 8.41 Left. Comparison of SNR of 14.4 keV Mossbauer spectra, taken with a Si-PIN detector system (MER instrument four diodes) and with a SDD detector system (advanced MIMOS instrument only one diode chip) Right. X-ray spectrum of a basalt (Ortenberg basalt see [366, 371], taken with a high resolution Si-drift detector system at ambient pressure (1 atm), demon-...

A portable isotopic neutron spectroscopy (PINS) detector can be used to help eliminate an anomaly or munitions as being dangerous. The PINS detector is only effective for six inches, thus the object does not have to be completely excavated. A larger truck-mounted version called pulsed fast neutron analysis (PFNA) can penetrate to five feet, but it is extremely dangerous to drive a heavy vehicle over a munitions site. Still larger permanently mounted versions are available for customs work, which can look through an 8-ft wide steel shipping container or semitrailer. 

Figure 8.24 Schematic of a silicon PIN detector. (Courtesy of Amptek, Inc. www.amptek.com.]...

The Unisantis XMF-104 X-ray microanalyzer (Unisantis S.A., www.unisantis.com) was used by researchers at the Institute for Roentgen Optics, Moscow, Russian Federation, to examine nonde-structively the composition of ancient coins from the fourth century BC through the second century AD. The fourth century BC coins were found to be an alloy of 82% Ag/18% Cu, but areas of pure Ag showed the inhomogeneity of the alloy. A drachma coin depicting Alexander was composed of 99% Ag/1% Cu. The XMF-104 system had a 50 W Mo tube, a 2-stage Peltier-cooled compact Si-PIN detector and polycapillary focused X-ray beam with a 50-250 pm focal spot. Spectra, images of the coins, and details are available at www.unisantis.com, application note 605. 

The pins are manually inserted into a perforated matrix plate, making any desired experimental arrangements within a 28 x 26 matrix. The control and safety assemblies are composed of a total of 48 pins that contain absorbing material. Each safety/control assembly has 12 pins. Detectors around the structure that sustains the matrix plate complement the critical arrangement, which is maintained within a stainless steel tank. Demineralized water is used as moderator and cooling refrigerant. The reactor reached criticality for the first time in November 1988, and since then it is used for training, validation of neutronic codes, and for determination of nuclear parameters for small LWR power reactors. 

W. Snoey.s et al, PIN Detector Arrays and Integrated Readout Circuitry on High-Resistivity Float-zone Silicon, submitted to IEEE Trans, on Electron Devices, UH-511-755-92. 

The sheet may also be inspected for the quality of welding and checked for pin-holes by a weld-hole detector before it is finally cut into lengths or wound onto rolls. 

Fig. 4.7. A semiconductor detector operated as a pin diode with a reverse voltage or bias. An incident X-ray photon ultimately produces a series of electron-hole pairs. They are "swept out" by the bias field of-500 V- electrons in the direction ofthe n-layer holes in the direction ofthe p-layer. Thus, a small charge pulse is produced after [4.21],...

Adjustable Workbench (PAW) instrument assembly. The SH shown in Figs. 3.15 and 3.16 contains the electromechanical transducer (mounted in the center), the main and reference Co/Rh sources, multilayered radiation shields, detectors and their preamplifiers and main (linear) amplifiers, and a contact plate and sensor. The contact plate and contact sensor are used in conjunction with the IDD to apply a small preload when it places the SH holding it firmly against the target. The electronics board contains power supplies/conditioners, the dedicated CPU, different kinds of memory, firmware, and associated circuitry for instrument control and data processing. The SH of the miniaturized Mossbauer spectrometer MIMOS II has the dimensions (5 x 5.5 x 9.5) cm and weighs only ca. 400 g. Both 14.4 keV y-rays and 6.4 keV Fe X-rays are detected simultaneously by four Si-PIN diodes. The mass of the electronics board is about 90 g [36],... 

Energy-dispersive spectrometry (EDS) is a technique of X-ray spectroscopy that is based on the simultaneous collection and energy dispersion of characteristic X-rays. Typical ED detectors are thermoelectrically cooled semiconductors (usually operated at 77 K), PIN diodes,... 

Figure 4.1. Typical X-ray setup with 2D detector in normal-transmission geometry. The intensity of the incident X-ray beam is measured in an ionization chamber (a). Thereafter it penetrates the sample which is subjected to some process. At a distance R (cf. Table 2.1 on p. 7) behind the sample the detector is recording the scattering pattern. In its center (b) the detector is protected by a beam stop. It is equipped with a pin-diode which records the intensity of the attenuated beam...

Figure 7.6. Detector efficiency for photodiodes. Spectra for (A) a silicon photodiode and (B) a PIN silicon photodiode are shown. The peak wavelength response of both detectors is at 960 nm,...

The ELLs can serve as modulated sources for long decay times of the type displayed by the ruthenium (Ru) complexes.(71) The large area of the ELL allows for substantial total intensity, so that the detector could be a simple PIN photodiode (Figure... 

Because of its hardness and noncorrosiveness, tantalum is used to make dental and surgical tools and implants and artificial joints, pins, and screws. The metal does not interact with human tissues and fluids. Since tantalum can be drawn into thin wires, it is used in the electronics industry, to make smoke detectors, as a getter in vacuum tubes to absorb residual gases, and as filaments in incandescent lamps. It has many other uses in the electronics industry. 

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