Radiation Hardened LIDAR Sensor – Design and performance evaluation
In scenarios involving radiation such as decommissioning of nuclear disasters and operating nuclear power plants, it is necessary to perform tasks including maintenance, demolition, and inspection using robots in order to protect human workers from harm. LIDAR (LIght Detection And Ranging) sensors are used for many demanding real-time tasks in robotics such as obstacle avoidance, localisation, mapping and navigation. Standard silicon-based electronics such as LIDAR fails quickly in gamma radiation, however high-radiation areas have a critical need for robotic maintenance to keep people safe. Sensors need to be developed which are able to cope with this environment. Existing literature regarding effects of gamma radiation on required LIDAR semiconductor components is summarised and alternative materials and components for providing the same type of functionality but with a greater gamma resistance are described. A set of transmitter and receiver circuits are designed utilising components expected to provide high (1 MGy) gamma radiation tolerance. Initial results testing the concepts of the laser transmission and detection shows reliable signal detection. Performance tests utilising multiple receivers show a linear relationship between receiver separation and measured time difference, allowing for the possibility of calibration of a sensor using the time difference between pulses. In conclusion, these results significantly de-risks the feasibility of long-term deployment of LIDAR systems utilising these approaches into environments with high gamma dose rates, such as nuclear fission decommissioning, big science facilities such as the Large Hadron Collider, and remote maintenance systems used in future nuclear fusion power plants such as STEP and EU-DEMO.