Low cost current mode data acquisition board for X-ray backscatter imaging systems

摘要

Compton backscatter imaging is a single-sided imaging technique and can be used as an excellent NDE tool for various applications. To develop an efficient and a high-resolution x-ray backscatter imaging system, a low-cost data acquisition electronic board to work with scintillation detectors in current mode is developed and tested. This in-house built current mode data acquisition board allows for higher count rate and to collect more information about the energy deposited in the detector. The board provides four independent data measuring channels running in current mode. Each channel can be configured with 500 integration selections and 2500 gain selections manually and digitally. The data from all four channels are sampled by a 32-bit micro-controller with onboard 16-bit high-speed ADCs with sample rates up to 1200 ksps/channel. The board also provides 22 general I/Os, which can be used to control mechanical components such as raster scanning tables, linear motion stages and rotating collimators. The total cost of this unique data acquisition board is less than $150. With an open system design, other modules can be added to this board to increase functionalities. This low-cost current mode data acquisition board has been tested on the backscatter imaging system at UF under different experiment setups. From the backscattered images of the concrete contrast tool, the minimum detectable depth of the defect is 1.5 mm with the RSD system and the data acquisition board. With its undeniable low price and from the results, this data acquisition board shows great potential in x-ray backscatter imaging and signal measurement applications such as non-destructive inspection of CFAT materials.