X-ray backscatter tomography for nondestructive evaluation at the Naval Research Laboratory

object size or inaccessibility. For several years NRL has been using a Philips ComScan semi-portableXBT unit to develop an underwater NDE system for Navy sonar domes on surface vessels. Along theway we have had opportunities to apply this new technology to samples of a number of other materials.We will describe progress toward our dome inspection system and results from other materials.Keywords: x-ray backscatter, tomography, composites, NDE, sonar domes1. INTRODUCTIONThe US Navy has a variety of weapons platforms which have overall desired design lifetimesof many decades, but which are plagued by subsystems which age far more rapidly than designs calledfor. Since it was historically a "steel" navy, those NDE techniques well developed for steel were often