| The research detailed in this thesis concerns the design and construction of a novel radiation imaging/detection camera for use in a non-destructive testing system, and development of the techniques involved with the use of a radioactive noble gas for non-destructive diagnostic engineering, (N.D.E). The choice of the specific radioactive noble gas was also a novel one. This imaging device and the use of the radioactive noble gas may be considered a new addition to the techniques available to perform N.D.E.;The detector images photons from a radioactive noble gas which has been concentrated in the flaws of the material. The radioactive noble gas is forced into a material by first creating a vacuum in a test chamber, and then injecting the radioactive noble gas into the said chamber. The radioactive noble gas uniformly distributes itself onto the material within the test chamber, including into any flaws on the test piece. Once the test piece is removed, it is wiped down, leaving the radioactive noble gas in the flaws. This allows the imaging device to localize any near surface minute flaws which existed in the material. The photons emitted from the flaws are then imaged by the radiation detector constructed with an incorporated customized microchannel plate (MCP) system for photon multiplication. The signals from the MCP are then digitized using a charge coupled device (CCD). The signals from the CCD could either be translated into a visual image (with any flaws located being enhanced and superimposed over a picture of the component) or analyzed using existing flaw recognition software.;The significance of this research is that it leads to a radiation camera imaging system which has improved imaging accuracy, and spatial resolution, fewer unidentified flaws and false positives than current techniques. The advantages of this approach for flaw imaging when compared to other available methods such as X-ray, eddy current or photomultiplier based radiation detectors. |
