The α Contamination Monitor based on LARD

The LRAD-based monitor was designed to detect the residual contamination of the equipment that needs to be efficiently monitored .The monitor measures the current created by the ions which are generated by the interact ion of alpha particles with air and which can be transported over significant distances (several meters) in an airflow generated by a small fan. The STM32F10x microcontroller was employed in building the hardware platform to achieve high-precision micro-current measurements. The detector can measure the small electric current of ions up to the level of fA and the sensitivity of this detector is about 5.29307fA/Bq. Some problems are discussed and put forward in the paper such as how to measure the radiation activity by experimental calibration, and how to improve the measurement accuracy of micro-current, and so on.