Lithium drifted silicon

Instrumentation. Traditional methods of alpha and beta spectrometry instrumentation have changed little over the past decade. Alpha spectrometric methods typically rely on semi-conductor or lithium-drifted silicon detectors (Si(Li)), or more historically gridded ion chambers, and these detection systems are still widely used in various types of uranium-series nuclide measurement for health, environmental, and... 

Lithium dichromate, molecular formula, properties, and uses, 6 562t Lithium diisopropylamide (LDA), 15 148 Lithium-drifted silicon [Si(Li)] detector, 26 434... 

Lithium-drifted silicon x-ray detectors designed to measure trace amounts of plutonium in soil samples have been fabricated by Walton et al. (1984). These diodes have been passivated with sputtered a-Si H, with a resulting lowering of leakage current at the operating low temperatures. 

The most frequently used silicon detector is a small pellet of lithium drifted silicon, some 6 mm in diameter and 3-4 mm thick. It is good only for X-rays, in the energy range between 4 and 50 keV. In fact, there are some standard sizes of Si(Li) detectors, areas of 30 and 100 mm are considered normal, anything else is a detector made by specifications of the user. 

The result is the lithium-drifted silicon counter sketched in Fig. 7-20. The crystal is virtually all intrinsic, with the p and n portions confined to thin surface layers, which are exaggerated in the drawing. The very small pulses from the counter are amplified to the millivolt level by a field-effect transistor, abbreviated FET. (There is no charge amplification, such as occurs in a gas counter. The pulse from the counter contains only the charge liberated by the absorbed x-rays.)... 

The X-ray signal in STEM is usually collected by compact solid state detectors based on lithium-drifted silicon diodes. The X-ray photon is sorted by energy, henee the alternative names for X-ray fluorescence analysis Energy Dispersive X-ray Spectroseopy (EDS or EDX). The typical energy resolution for an X-ray photon is of on the order of 150 eV This is suffieient in most cases for resolving peaks of different elements, but is inadequate for deteeting... 

The x-ray fluorescence system consisted of a radioactive source as the excitor and a 200-ev resolution (FWHM) lithium-drifted silicon detector with standard electronics. Only 15 minutes were required to completely process a sample. 

The excellent resolution provided by the more recently developed lithium-drifted silicon [Si(Li)] and germanium [Ge(Li)] semiconductor detectors (see Chap. 

The most common semiconductor detector for laboratory EDXRF systems is the lithium-drifted silicon diode, represented as Si(Li). (It is called a silly detector for short). A schematic diagram of a silicon lithium-drifted detector is shown in Fig. 8.30. A cylindrical piece of pure, single crystal silicon is used. The size of this piece is... 

The detectors used in the various forms of EDXRF are semiconductor detectors Conventionally, two types, i. e. lithium drifted silicon (Si(Li)) and hyperpure germa nium (HP-Ge) detectors are used. Their main advantages are their compact size the non-moving system components, and relatively good energy resolution which optimally is of the order of 120 eV at 5.9 keV. Because of their operation prin... 

Semiconductor technology is still a rapidly developing field that has seen the introduction of new detector types in recent years. However, the standard detector type on which ED-XRF technology was founded is the lithium-drifted silicon detector, Si(Li). This is the detector type against which the performance of new types of semiconductor detector is evaluated. 

Semiconductor transducers have assumed major importance as detectors of X-radiation. These devices are sometimes called lithium-drifted silicon detectors, Si(Li), or lithium-drifted germanium detectors, Ge(Li). 

Lithium atoms are highly mobile at room temperature. Thus lithium-drifted silicon (Si [Li]) detectors tend to undrift... 

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