Fast High Resolution, High Contrast Microfocus X-Ray Computed Tomography Reconstruction Algorithms for ICBM Components

TECHNOLOGY AREA(S): Space Platforms
OBJECTIVE: Develop algorithms, software and computer system that eliminate artifacts, enhance image quality and improve speed of microfocus cone-beam computed tomography applied to nondestructive testing of small components in ICBM systems.
DESCRIPTION: Microfocus cone-beam computed tomography (CBCT) is used by the Air Force, for nondestructive testing, to inspect small components of Intercontinental Ballistic Missile (ICBM) systems. The inspections cover a breadth of applications, including verification of reliability, manufacturing defects, stress and aging characterization. Defects, material changes, wear or aging may cause a component to fail. Investigations of the causes of failures and studies into the reliability of systems and devices all warrant microfocus CT inspection. Microfocus CT systems like all CT systems have inherent problems particular to the type of system. Despite the many advantages of microfocus cone beam CT technology, it suffers from artifacts and distortion due to not having a full complement of information for a mathematically accurate inverse.
Sometimes it is difficult to accurately image the axial extremes of a sample because of these issues. Scatter is severe compared to standard CT because collimation is not used. Beam hardening can be severe. Iterative solutions can suffer from long processing times, considering that cone beam datasets and the reconstructed volume are large compared to many standard CT configurations. Solutions to these problems should include innovative software algorithms and computer systems that will push the limits of the visual and 3D information currently provided by microfocus cone beam CT. Advanced scanning geometries, including the helical cone beam geometry, get around many of the problems, but require more complex equipment, scanning, data and time.
This topic seeks innovative solutions which include computer algorithms, software and computer hardware methods that address all of the following limitations: (1) cone beam artifacts, including axial smearing caused by the incomplete data of the cone beam geometry, (2), data truncation, (3), resolving power and magnification limits, (4), objects that do not fit in the viewing field, (5), noise d settings, (6), aliasing, (7), Compton scatter, (8), nonlinearities caused by high Z materials, (9), beam hardening, (10), speed of computation, (11), limit in volume size.
PHASE I: Conduct of one or more proof-of-concept tests of promising technologies to accomplish the objective, and develop a plan for g the proof-of-concept into a prototype solution of technologies that are viable candidates for supporting ICBM imaging technologies.
PHASE II: Demonstrate prototype on actual CT images acquired at Hill AFB, UT. This demonstration will show measurable improvements over in 2D and 3D visualization, analysis of CT images and defect evaluation. End of effort: Deliver a final polished prototype with documentation.
PHASE III: Military: Focus is ICBM small components. Industrial computed tomography for nondestructive testing is a growing field with a growing market. Commercial: This technology could be used on any industrial cone-beam CT system with the same results. Manufacture of components for aircraft andautomobiles.
REFERENCES: 1.ASTM E1441-97 (Reapproved 2003), Standard Guide for Computed Tomography (CT) Imaging (1997), West Conshohocken, PA.2.ASTM E1695-95 (Reapproved 2013), Standard Test Method for Measurement of Computed Tomography (CT) System Performance (1995), West Conshohocken, PA.3.ASTM 1570-00 (Reapproved 2011), Standard Practice for Computed Tomographic (CT) Examination (2000), West Conshohocken, PA.
KEYWORDS: Microfocus Computed Tomography, Nondestructive Inspection, Artifacts And Noise, ICBM Components, Cone-beam CT Images