The Application Of Scintillating Fiber Optics In A Diode Array Digital Radiography System

Abstract

Research to evaluate the use of scintillating fiber optics (SFO) to replace traditional phosphor screens as an imaging detector in a digital radiographic system is presented. A SFO-based detector was constructed for a Diode Array Digital Radiography (DADR) system. System image quality was evaluated with five characterization criteria: spatial resolution, signal-to-noise ratio (SNR), large-area contrast detectability, responsivity, and inspection task performance. It has been concluded from this evaluation that the spatial resolution, SNR and large-area contrast detectability are superior to that observed with phosphor screens. Spatial resolution is typically 8-9 line-pairs/" (lp/mm) for SFO, while the phosphor screen resolution was typically 2-6 lp/mm. However, responsivity (i.e., the system sensitivity), with SFO is much lower than measured with phosphor screens. absorption efficiency of SFO is high, the overall efficiency is lower than for phosphor screens. By adjusting the gains of an image intensifier and an electronic amplifier, an adequately large signal output for a feasible x-ray dose input was obtained with the SFO system. The SFO system has produced images of electronic assemblies and met the requirements of the ASTM 801E #4. The experimental results indicate that the SFO detector is comparable to phosphor screens at low x-ray energies ( < 300 KVp), and is expected to have superior performance for higher energy photon detection.In this energy range, although the x-ray INTRODUCIIONThe objective of this research was to evaluate the use of scintillating fiber optics (SFO) to replace traditional phosphor screens as the imaging detector in a digital radiographic system. x-ray image quality is a function of two basic factors: number of photons detected per unit area and the spreading of the x-ray image inherent in the