Compton Imaging Tomography System for In-Process Submerged Arc Welding Quality Control

To address the Navy need for the methodologies and associated enabling technologies to accurately control the depth of weld penetration during the Submerged Arc Welding (SAW) process, Physical Optics Corporation (POC) proposes to develop a completely novel Compton Imaging Tomography System for in-process SAW quality control (CITSAW). The CITSAW system contains: 1) an industrial 200–450 keV X-ray source; 2) an X-ray camera based on a POC-developed apodized Gaussian aperture array, a high-absorption and high-resolution capillary scintillator, and a sensitive CCD camera with a powerful image intensifier; and 3) POC’s original software for CIT providing real-time, current welding depth finding for SAW process control, and other defect detection (if necessary) using full 3D-image reconstruction. The X-ray source and the X-ray camera are both mounted in one case, on the same side of the object, and moved together with SAW electrodes along a weld. In Phase I, POC will demonstrate feasibility of the system for measurement of the depth of weld penetration using prepared coupons and a benchtop prototype, and make estimates of the return on investment and Total Ownership Cost reduction when CITSAW is implemented. In Phase II, POC will design and test a full CITSAW system prototype.