A high-speed system for three-dimensional X-ray and neutron computed tomography

Abstract

Computed tomography for nondestmctive evaluation applications has been limited by system cost, resolution, and time requirements for three-dimensional data sets. FlashCT (Flat panel Amorphous Silicon High resolution Computed Tomography) is a system developed at Los Alamos National Laboratory to address these three problems. Developed around a flat panel amorphous silicon detector array, FlashCT is suitable for high energy x-ray and neutron computed tomography at 127 micron resolution. For objects smaller than 8 inches in any dimension, the system is capable of generating 360 views to create a high resolution three-dimensional tomographic dataset in less than 40 minutes, many times faster than with conventional linear detector array systems. Overall system size is small, allowing rapid transportation to a variety of radiographic sources. During system development, issues including integration time adjustment, exposure monitoring, and detector flaw correction were addressed to provide high quality output images suitable for later reconstmction into two- or three-dimensional density maps. System control software was developed in Lab VIEW for Windows NT to allow multithreading of data acquisition, data correction, and staging motor control. The system control software simplifies data collection and allows fiilly automated control of the data acquisition process, leading toward remote or unattended operation. The custom data processing software provides a simple graphical interface to control the calibration, filtering, and reconstmction of the acquired data.