Linear Detectors Arrays (LDAs) - XV-LDA Series
Underwater LDA Test image on oil-filled flexible riser, 10C Ir192
410mm length Crystal LDA, 0.8mm pitch, 512 pixels under construction
Single channel (51mm) crystal/ photo-diode, 10mm deep, 400μm pitch
Underwater crystal LDA for use with Ir192
Single channel (51mm) crystal/ photo-diode, 10mm deep, 400μm pitch
Linear Detector Arrays (LDAs) are one-dimensional x-ray detectors that consist of a single row of x-ray sensitive detectors. In order to obtain a two-dimensional image from such a detector it is necessary to move the detector, or the object in a direction perpendicular to the length of the array. In order to maintain regular image geometry (square pixels), the speed of movement has to be carefully synchronised with the line exposure time of the array. The width of two-dimensional images acquired by an LDA are limited by the number of pixels comprising the width of the array, however, the length is unlimited and LDAs are ideally suited to applications where the objects are moving on a conveyor belt. LDAs are also ideally suited to 2D CT systems which obtain single CT slices through an object. Although slower, 2D CT is preferable to 3D CT (using an area detector) for applications where scattered x-rays are a problem, for example for high energy applications, radioactive components or when examining dense materials.
SIS manufactures a range of XV-LDA linear detector arrays, with resolutions of 200, 400, 800 and 1600 microns for use from 20kV to 450kV. These detectors have been specifically developed for use in digital x-ray inspection. All these detectors can be supplied with a GadOx scintillator or a ladder of CdWO4 individual crystals (not 200 micron version). We also manufacture deep crystal versions for use with isotopes such as Iridium 192.
The arrays can operate on an internal trigger, with line exposure times from 2ms to 4000ms, line data is digitised at 16-bit resolution and communicated with the host computer using ethernet 10/100.