Gamma ray monitors for MultiMod’Air, a mobile environmental monitoring platform

Multimod’Air is a demonstrator of a mobile and energy self-sufficient platform for environmental measurement in any place of interest from cities, rural or industrial outdoor areas. The platform comprises a dozen of detectors including gaseous pollutant and fine particle sensors for pollution monitoring, as well as a complete weather station (rainfall intensity, wind speed, atmospheric pressure, relative humidity, temperature, solar irradiance and more) and gamma-ray monitors. The paper is specifically devoted to the gamma ray detectors for radiation monitoring with a focus on their architecture, real time and offline data analysis process and performance. Two different and complementary gamma ray monitors have been designed and integrated. The first prototype operates a Kromek GR1+ detectors while the second relies on the advanced multichannel Caliste-O detector technology initially designed for astrophysics applications and recently used for nuclear monitoring ground applications. Both detectors’ electronics are coupled to a local ODROID XU4 microcomputer for data acquisition, management and communication. While GR1+ detector sends an integrated spectrum every minute, Caliste-O both sends aggregated spectra over all channels every minute and photon event list on demand. The two autonomous prototypes have been successfully tested outdoors, and the results of the measurements are presented.