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Elastic recoil detection analysis was originally developed for hydrogen detection [17] or a light element (H, He, Li, C, O, Mg, K) profiling with an absorber foil in front of the energy detector for beam suppression. [1] Using an absorber foil prevents the higher energy ion beam from striking the detector and causing degradation.
In this region, a beam of light crosses the column of analyte and the scattering of light is measured by a photodiode or photomultiplier tube. The detector's output is non-linear across more than one order of magnitude and proper calibration is required for quantitative analysis. [7]
The scattering volume ΔV from which scattered light reaches the detector is determined by the detector's field of view generally restricted by apertures, lenses and stops. Consider now a MALS measurement made in a plane from a suspension of N identical particles/molecules per ml illuminated by a fine beam of light produced by a laser.
The configuration of the ion beam apparatus can be changed and made more complex with the incorporation of additional components. The techniques for ion beam analysis are designed for specific purposes. Some techniques and ion sources are shown in table 1. Detector types and arrangements for ion beam techniques are shown in table 2.
Rutherford backscattering spectrometry (RBS) is an analytical technique used in materials science.Sometimes referred to as high-energy ion scattering (HEIS) spectrometry, RBS is used to determine the structure and composition of materials by measuring the backscattering of a beam of high energy ions (typically protons or alpha particles) impinging on a sample.
Often the detector is a simple Faraday plate coupled to a transimpedance amplifier, however, more advanced ion mobility instruments are coupled with mass spectrometers in order to obtain both size and mass information simultaneously. It is noteworthy that the detector influences the optimum operating conditions for the ion mobility experiment. [32]
Within the machine the transducer that detects fluorescence created from the upper beam is located a distance away from the sample and at a 90-degree angle from the incident, upper beam. The machine is constructed like this to decrease the stray light from the upper beam that may strike the detector. The optimal angle is 90 degrees.
A typical diffractometer consists of a source of radiation, a monochromator to choose the wavelength, slits to adjust the shape of the beam, a sample and a detector. In a more complicated apparatus, a goniometer can also be used for fine adjustment of the sample and the detector positions. When an area detector is used to monitor the diffracted ...