2020/09/23 by A. A. Aguilar-Arevalo, X. Bertou, Aguilar-Arevalo, Alexis +39
Health Professions · Physics and Astronomy · #Applied Physics (physics.app-ph) #FOS: Physical sciences #Instrumentation and Detectors (physics.ins-det) #Radiation Detection and Scintillator Technologies #Radioactive Decay and Measurement Techniques #Radioactivity and Radon Measurements
paper · pdf · doi:10.48550/arxiv.2009.11227
openalex publication_date 2020/09/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11
This paper explores the prospect of CMOS devices to assay lead in drinking\nwater, using calorimetry. Lead occurs together with traces of radioisotopes,≠.g. Lead-210, producing \γ-emissions with energies ranging from 10 keV\nto several 100 keV when they decay; this range is detectable in silicon\nsensors. In this paper we test a CMOS camera (Oxford Instruments Neo 5.5) for\nits general performance as a detector of x-rays and low energy \γ-rays\nand assess its sensitivity relative to the World Health Organization upper\nlimit on lead in drinking water. Energies from 6 keV to 60 keV are examined.\nThe CMOS camera has a linear energy response over this range and its energy\nresolution is for the most part slightly better than 2 %. The Neo sCMOS is not\nsensitive to x-rays with energies below \∼ ! !10 keV. The smallest\ndetectable rate is 40\±3 mHz, corresponding to an incident activity on the\nchip of 7\±4 Bq. The estimation of the incident activity sensitivity from\nthe detected activity relies on geometric acceptance and the measured\nefficiency vs. energy. We report the efficiency measurement, which is\n0.08\±0.02 % (0.0011\±0.0002 %) at 26.3 keV (59.5 keV). Taking\ncalorimetric information into account we measure a minimal detectable rate of\n4\±1 mHz (1.5\±0.1 mHz) for 26.3 keV (59.5 keV) \γ-rays, which\ncorresponds to an incident activity of 1.0\±0.6 Bq (57\±33 Bq). Toy Monte\nCarlo and Geant4 simulations agree with these results. These results show this\nCMOS sensor is well-suited as a \γ- and x-ray detector with sensitivity\nat the few to 100 ppb level for Lead-210 in a sample.\n