Position-sensitive Detector (position-sensitive + detector)

Distribution by Scientific Domains


Selected Abstracts


High-temperature (1500,K) reciprocal space mapping on a laboratory X-ray diffractometer

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 2 2007
R. Guinebretière
A laboratory X-ray diffractometer devoted to the in situ characterization of the microstructure of epitaxic thin films at temperatures up to 1500,K has been developed. The sample holder was built using refractory materials, and a high-accuracy translation stage allows correction of the dilatation of both the sample and the sample holder. The samples are oriented with respect to the primary beam with two orthogonal rotations allowing the registration of symmetric as well as asymmetric reciprocal space maps (RSMs). The association of a monochromatic primary beam and a position-sensitive detector allows the measurement of RSMs in a few minutes for single crystals and in a few hours for imperfect epitaxic thin films. A detailed description of the setup is given and its potential is illustrated by high-temperature RSM experiments performed on yttria-doped zirconia epitaxic thin films grown on sapphire substrates. [source]


A high-resolution X-ray diffractometer for the study of imperfect materials

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 5 2002
A. Boulle
A high-resolution X-ray diffractometer devoted to the study of imperfect materials (mainly oxides and ceramics) is presented. It is based on a rotating anode generator, a four-bounce monochromator, a five-movement sample holder and a curved position-sensitive detector (PSD). This setup allows rapid acquisition of a reciprocal-space map (in less than 10,h) even for very poorly diffracting materials. The two-dimensional instrumental profile is calculated taking into account each optical element in the beam path. The one-dimensional instrumental profiles corresponding to widely used scans (, scan, ,,2, scan, rocking curve and powder scan) are also calculated. In the three former cases, the setup exhibits an excellent angular resolution (0.003°), whereas in the latter case the resolution is lowered by one order of magnitude at the benefit of a strong increase in the collected intensity. The possibilities of this diffractometer are illustrated with three examples: an epitaxic layer, a microstructured single crystal and a powder. [source]


Temperature gradient analyzers for compact high-resolution X-ray spectrometers

JOURNAL OF SYNCHROTRON RADIATION, Issue 1 2010
D. Ishikawa
Compact high-resolution X-ray spectrometers with a one-dimensional temperature gradient at the analyzer crystal are considered. This gradient, combined with the use of a position-sensitive detector, makes it possible to relax the usual Rowland-circle condition, allowing increased space at the sample position for a given energy resolution or arm radius. Thus, for example, it is estimated that ,meV resolution is possible with a 3,m analyzer arm and 200,mm clearance between the sample and detector. Simple analytic formulae are provided, supported by excellent agreement with ray-tracing simulations. One variation of this method also allows the detector position sensitivity to be used to determine momentum transfer, effectively improving momentum resolution without reducing (slitting down) the analyzer size. Application to medium-resolution (,10,100,meV) inelastic X-ray scattering spectrometers with large angular acceptance is discussed, where this method also allows increased space at the sample. In some cases the application of a temperature gradient can improve the energy resolution even with a single-element detector. [source]


Lattice Location of Implanted 147Nd and 147*Pm in GaN Using Emission Channeling

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 1 2003
B. De Vries
Abstract The lattice location of 147Nd and 147*Pm in thin-film, single-crystalline hexagonal GaN was studied by means of the emission channeling technique. The angular emission yields of ,, particles and conversion electrons emitted by the radioactive isotopes 147Nd and 147*Pm were measured using a position-sensitive detector following 60 keV room temperature implantation at a dose of 1 × 1013 cm,2 and annealing at 900 °C. The emission patterns around the [0001], [102], [101], and [113] crystal axes give direct evidence that the majority (,70%) of Nd and Pm atoms occupy substitutional Ga sites. [source]


POWTEX , the high-intensity time-of-flight diffractometer at FRM II for structure analysis of polycrystalline materials

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 5 2008
Harald Conrad
In order to provide the large chemistry and materials science as well as the geosciences communities with a powerful tool for rapid data acquisition, a time-of-flight powder diffractometer to be installed at the new Munich reactor has been designed. The time-of-flight technique is expected to outperform a monochromator instrument by at least an order of magnitude in data acquisition time, particularly on small samples of less than a cubic centimetre. The construction of this innovative type of diffractometer utilizes modern components such as focusing super-mirror neutron guides, a four-unit high-speed disk chopper system and linear position-sensitive detectors covering a solid angle of about 2, steradian. The diffractometer design enables an easy enlargement of the focal spot size and is therefore equally well suited for the texture analysis of large geological and archaeological samples. [source]