FPGA-Based Real-Time Data Acquisition for Ultrafast X-Ray Computed Tomography

Ultrafast X-ray computed tomography (UFXCT) is a fast tomographic imaging technique based on the principle of electron beam scanning. It is used for the investigation of transient multiphase flows. A UFXCT scanner comprises multiple detector modules generating gigabytes of raw data per second for imaging rates of up to 8000 fps. During the data acquisition, these data are stored in RAM on each detector module and can therefore only be accessed after the acquisition. This limits the applicability of UFXCT systems because real-time control of the scanned process or the scanner itself is not possible. To achieve this, data streaming with low latency and high throughput is necessary. Using the newly developed FPGA-based data acquisition described in this article, the data acquisition is enhanced to real-time operation, i.e., streaming the acquired data to the processing computer within microseconds of their acquisition. The developed FPGA hardware implementation handles control of peripherals [such as analog-digital converters (ADC)], synchronization between detector modules, electron beam deflection, and data transfer via Gigabit Ethernet (GbE).