Developing an Automated Explosives Detection Prototype Based on the AS&E 101ZZ System

Abstract

This thesis describes the development of a multi-sensor, multi-energy x-ray prototype for automated explosives detection. The system is based on the American Science and Engineering model 101ZZ x-ray system. The 101ZZ unit received was an early model and lacked documentation of the many specialized electronic components. X-ray image quality was poor. The system was significantly modified and almost all AS&E system electronics bypassed: the x-ray source controller and conveyor belt motor were made computer controllable; the x-ray detectors were re-positioned to provide forward scatter detection capabilities; new hardware was developed to interface to the AS&E pre-amplifier boards, to collect image data from all three x-ray detectors, and to transfer the data to a personal computer. This hardware, the Differential Pair Interface Board (DPIB), is based on a Field Programmable Gate Array (FPGA) and can be dynamically re-configured to serve as a general purpose data collection device in a variety of applications.

Software was also developed for the prototype system. A Windows NT device driver was written for the DPIB and a custom bus master DMA collection device. These drivers are portable and can be used as a basis for the development of other Windows NT drivers. A graphical user interface (GUI) was also developed. The GUI automates the data collection tasks and controls all the prototype system components. It interfaces with the image processing software for explosives detection and displays the results. Suspicious areas are color coded and presented to the operator for further examination.