Image plate

Industrial Application of Computed Radiography with Luminescence Imaging Plates. 

Computed radiography with Luminescence Imaging Plates (IP) has become a routine method in medical applications. It is a new medium for filmless radiography. Since the last five years several tests were performed to check this method for industrial NDT [1-3]. ASTM already issued a proposal for a standard. 

Imaging plates are exposed similar to radiographic films. They are read out by a LASER-scanner to a digital image without any developing process. After optical erasing of the virtual picture the same IP can be used cyclic up to more than 1000 times. The life time is limited by the mechanical stability of the IP s. An IP consists of a flexible polymer carrier which is coated with the sensitive layer. This layer is covered with a thin transparent protective foil. 

New Possibilities in Neutron Radiography with Imaging Plates. 

The flexible large area screen with photostimulable phosphor called the imaging plate, which temporarily stores the image induced by the ionizing radiation, e g. by X-rays, electrons or other charged particles ... 

An experimental teclmique that is usefiil for structure studies of biological macromolecules and other crystals with large unit cells uses neither the broad, white , spectrum characteristic of Lane methods nor a sharp, monocliromatic spectrum, but rather a spectral band with AX/X 20%. Because of its relation to the Lane method, this teclmique is called quasi-Laue. It was believed for many years diat the Lane method was not usefiil for structure studies because reflections of different orders would be superposed on the same point of a film or an image plate. It was realized recently, however, that, if there is a definite minimum wavelengdi in the spectral band, more than 80% of all reflections would contain only a single order. Quasi-Laue methods are now used with both neutrons and x-rays, particularly x-rays from synclirotron sources, which give an intense, white spectrum. 

X-ray data are recorded either on image plates or by electronic detectors... 

X-ray data are recorded either on image plates or by electronic detectors The rules for diffraction are given by Bragg s law Phase determination is the major crystallographic problem Phase information can also be obtained by Multiwavelength Anomalous Diffraction experiments... 

Fig. 7. A typical X-ray diffraction pattern of the Fepr protein fromZJ. vulgaris (Hil-denborough). The pattern was recorded on station 9.6 at the Synchrotron Radiation Source at the CCLRC Daresbury Laboratory using a wavelength 0.87 A and a MAR-Research image-plate detector system with a crystal-to-detector distance of 220 nun. X-ray data clearly extend to a resolution of 1.5 A, or even higher. The crystal system is orthorhombic, spacegroup P2i2i2i with unit cell dimensions, a = 63.87, b = 65.01, c = 153.49 A. The unit cell contains four molecules of 60 kDa moleculEu- weight with a corresponding solvent content of approximately 48%.

Fig. 9.30 (a) NLE setup to record the time response of a rotating resonantly scattering Fe foil on an image plate. The direction of the radioactive decay k t) deviates from the direction of ko by an angle ip that has developed during the delay time t after excitation. 

HHLM = high heat-load monochromator, (b) NLE time spectrum of the radiation, which was scattered by a Fe foil rotating at 10 kHz and which is obtained after background correction of the image plate data. The spectrum was obtained during a 1 min exposure. (Taken from [75])... 

Fig. 3. Comparison between IP-One kit versus calcium mobilization assay (384-well format). Human embryonic kidney (HEK) 293 cells expressing a chemokine receptor were evaluated on HTRF IP-One kit (CisBio, Bedford, MA) and fluroescent imaging plate reader (FLIPR) with Calcium 3 kit (Molecular Devices, Mountain View, CA).

CCD detectors (and also image plates), this contamination is a potential source of systematic errors because these devices cannot discriminate with respect to energy. 

GEL Image data format returned by image plate scanners... 

A variety of detectors is used in the field of X-ray scattering. In fact, the proper choice of the detector (as well as the sample thickness) is essential for good quality of the recorded data, whereas the intensity of the synchrotron radiation determines the minimum cycle time between two snapshots - if a modern CCD detector is used. Gas-filled detectors cannot be used to record high-intensity scattering patterns. Image plates need a minimum time of 2 min for read-out and erasure. 

Image plates use stimulated luminescence from storage phosphor materials. The commercially available plates are composed of extremely fine crystals of BaFBrEu2+. X-rays excite an electron of Eu2+ into the conduction band, where it is trapped in an F-center of the barium halide with a subsequent oxidation of Eu2+ to Eu3+. By exposing the BaFBrEu" complex to light from a HeNe laser the electrons are liberated with the emission of a photon at 390 nm [38]. 

If the progress of laboratory X-ray sources continues, gas-filled detectors will probably be replaced by image plates with automatic read-out. 

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