Non-destructive Imaging Applications Research Articles

Microwave Imager Design with 2.46 GHz Microstrip Patch Antennas

In this study, microwave imager design is aimed by using a series of microstrip patch antennas operating in the 2.46 GHz frequency band. The designed microwave imager has a 24-sided cylindrical shape and includes 5x1 microstrip patch antennas placed at 45˚ angles. The overall working principle of the microwave imager is based on the back reflection and transmission values between the transmitter and receiver antennas. The 40 microstrip patch antennas inside the microwave imager operate as both a receiver and a transmitter and the transmission values between each other (S 21 , S 31 , S 41 , S 21 etc.) are capable of mapping the internal space in three dimensions with the required algorithm. The microstrip antennas in the designed structure have been chosen for their small volume, easy integration, versatility, low profile, and the most commonly used 2.46 GHz frequency is used as the operation band. The most important achievement of this study is to support medical imaging practices; the detection of cancerous areas such as breast cancer can be determined by the interaction between antennas and is the aim of this study. In addition, the developed microwave imager can also be used in concrete mapping and non-destructive imaging applications in the construction sector. Besides, the designed configuration has another advantage due to its low cost.

Automating High-Precision X-Ray and Neutron Imaging Applications With Robotics

Los Alamos National Laboratory and the University of Texas at Austin recently implemented a robotically controlled nondestructive testing (NDT) system for X-ray and neutron imaging. This system is intended to address the need for accurate measurements for a variety of parts and, be able to track measurement geometry at every imaging location, and is designed for high-throughput applications. This system was deployed in a beam port at a nuclear research reactor and in an operational inspection X-ray bay. The nuclear research reactor system consisted of a precision industrial seven-axis robot, 1.1-MW TRIGA research reactor, and a scintillator-mirror-camera-based imaging system. The X-ray bay system incorporated the same robot, a 225-keV microfocus X-ray source, and a custom flat panel digital detector. The robotic positioning arm is programmable and allows imaging in multiple configurations, including planar, cylindrical, as well as other user defined geometries that provide enhanced engineering evaluation capability. The imaging acquisition device is coupled with the robot for automated image acquisition. The robot can achieve target positional repeatability within 17 $\mu \text{m}$ in the 3-D space. Flexible automation with nondestructive imaging saves costs, reduces dosage, adds imaging techniques, and achieves better quality results in less time. Specifics regarding the robotic system and imaging acquisition and evaluation processes are presented. This paper reviews the comprehensive testing and system evaluation to affirm the feasibility of robotic NDT, presents the system configuration, and reviews results for both X-ray and neutron radiography imaging applications. Note to Practitioners —While looking for ways to improve throughput and increase efficiency in nondestructive imaging applications, the NonDestructive Testing and Evaluation Group at the Los Alamos National Laboratory decided to take a look at automation opportunities. Digital radiography and computed tomography are time-consuming processes, making them ideal candidates for robotic solutions. Radiography applications often require several images to be acquired from different angles and a lot of time they have to be very precise so that the feature of interest is identifiable and the resulting image meets the client’s requirements. With the robot acting as the motion control system, the imaged part can be placed directly in the beam path and oriented in six degrees of freedom. The robot can achieve significantly higher levels of precision than a human and has the ability to adjust the part while the source is active. The system also reduces levels of radiation our staff is exposed to, as the robot is setup to handle radioactive and hazardous parts. Not only does the robot move parts more precisely and with higher resolution than humans, but it also adds additional flexibility in the type and nature of images that the lab can produce. Future work will involve using this system for advanced automated scans such as achieving evenly spaced views around a sphere autonomously, since this system has not yet been used for more advanced scans beyond helical scanning. A tightly linked feedback loop between the robot and imaging code in which the imaging code would autonomously communicate to the robot what additional views are needed to reduce imaging error can also be explored.