ASTM E 1931 : 2016 : R2022

1.1Purpose—This guide covers a tutorial introduction to familiarize the reader with the operational capabilities and limitations inherent in a single non-computed X-ray Compton Scatter Tomography (CST). Also included is a brief description of the physics and typical hardware configuration for CST. This single technique is still used for a small number of inspections. This is not meant as comprehensive guide covering the variety of Compton scattering techniques that are now used for non-destructive testing and security screen screening.

1.2Advantages—X-ray Compton Scatter Tomography (CST) is a radiologic nondestructive examination method with several advantages that include:

1.3Applications—This guide does not specify which examination objects are suitable, or unsuitable, for CST. As with most nondestructive examination techniques, CST is highly application specific thereby requiring the suitability of the method to be first demonstrated in the application laboratory. This guide does not provide guidance in the standardized practice or application of CST techniques. No guidance is provided concerning the acceptance or rejection of examination objects examined with CST.

1.4Limitations—As with all nondestructive examination methods, CST has limitations and is complementary to other NDE methods. Chief among the limitations is the difficulty in performing CST on thick sections of high-Z materials. CST is best applied to thinner sections of lower Z materials. The following provides a general idea of the range of CST applicability when using a 160 keV constant potential X-ray source:

The limitations of the technique must also consider the required X, Y, and Z axis resolutions, the speed of image formation, image quality and the difference in the X-ray scattering characteristics of the parent material and the internal features that are to be imaged.

1.5The values stated in both inch-pound and SI units are to be regarded separately as the standard. The values given in parentheses are for information only.

1.6This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.7This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.