Backscatter apparatus

Figure 13.3. Schematic diagram of backscatter apparatus. (From Ref. 2, with permission from the Electrochemical Society.)...

FIGURE 21-13 Rutherford backscattering apparatus. An ion beam from an accelerator is focused on the sample. Backscattered ions are delected with a solid-state particle detector. 

Figure 6 (a) Absorption remote sensing apparatus. (1) Tunable laser, (2) polluted region, (3) remote retroreflector, (4) telescope, (5) detector. (b) Backscatter remote sensing apparatus. (1) Laser, (2) polluted region, (3) telescope, (4) spectrometer and detector (Reproduced by permission from Analyt. Chim. Acta, 1974, 71, 277)... 

Fig. 2.18 Schematic drawing for the progress of a DLS measurement (a) Setup of a DLS-apparatus in backscattering mode, (b) Typical intensity fluctuation for a large ( ) and a small (—) molecule, (c) Correlogram for a large ( - ) and a small (—) molecule. As can be seen, correlograms for small molecules decay mwe rapidly, (d) Obtained size distributions by intensity...

Remote gas-sensing systems can also be grouped according to the type of equipment used at the remote end. For example, double-ended systems, such as DOAS, have a remote source, while TDLAS is often operated with a remote reflector or detector. The principal example of a single-ended system is DIAL, which depends on atmospheric backscatter and therefore has a single apparatus that includes both the transmitter and the receiver. 

The Mossbauer apparatus consists of an emitter, an absorber, and a y-ray detector. In a typical Mossbauer experiment, which can be performed either in transmission or in backscattering mode, a radioactive source is mounted on a velocity transducer which imparts a smoothly varying motion to the souree of the y-rays (relative to the absorber, which is held stationary), up to a maximum of several cm/s (Fig. 1.42). In practice, a source is needed which decays to the excited state of the nucleus of interest with a sufficiently long lifetime such that experiments are practical. The source usually consists of nuclei in the excited state which are obtained... 

In the field the apparatus is calibrated before each series of test to measure the backscatter of the area. Figure B.28 and Figure B.29 show the preparation and measurement with a nuclear probe next to the hole of a sand cone test for calibration purposes. 

DUV light was focused on the sample surface with an objective lens made of quartz. The Raman scattered light was collected with the same objective in a backscattering geometry and delivered to a spectrometer. The apex of the aluminum-coated tip was set in contact with the sample surface using an atomic force microscope apparatus. 

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