Production and characterization of a 222Rn-emanating stainless steel source.

Precise radon measurements are a requirement for various applications, ranging from radiation protection over environmental studies to material screening campaigns for rare-event searches. All of them ultimately depend on the availability of calibration sources with a known and stable radon emanation rate. A new approach to produce clean and dry radon sources by implantation of 226Ra ions into stainless steel has been investigated. In a proof of principle study, two stainless steel plates have been implanted in collaboration with the ISOLDE facility located at CERN. We present results from a complete characterization of the sources. Each sample provides a radon emanation rate of about 2 Bq, which has been measured using electrostatic radon monitors as well as miniaturized proportional counters. Additional measurements using HPGe and alpha spectrometry as well as measurements of the radon emanation rate at low temperatures were carried out. • Production of 222Rn emanating stainless steel sources by implantation of 226Ra. • Measurement of the implanted activity (8 Bq) with HPGe- and alpha-spectrometry. • Radon emanation rate (2 Bq) measured by radon monitor and proportional counter. • Recoil dominated emanation without significant dependence on temperature and pressure. [ABSTRACT FROM AUTHOR]