A Monte Carlo study of radon detection in cylindrical diffusion chambers

Theoretical and experimental study of the LR-115 detector response in a non-commercial radon monitor

B.trαcks, a simulation program for SSNTD's sensitivity, has been developed to study the response of LR-115 (cellulose nitrate) and CR-39 (poly allyl glycol carbonate) nuclear track detectors. Detectors are located inside detector holders and are used for radon measurements. The program incorporates a variety of special features gathered together to achieve good agreement between theoretical approach and experimental results. The input parameters to study the detector response are radon exposure, geometry and dimensions of a detector holder (it can be cylindrical, conical or semi-spherical), entrance type for radon gas, detector type, and V function (four different functions were selected from literature). The output results are detector response and radon progeny distribution onto internal chamber walls. In this article, the response of the LR-115, which is placed inside a non-commercial-conductive radon monitor based on diffusion chambers called G2, was theoretically and experimentally studied. The common Monte Carlo simulation procedure and an alternative approach that replicates how monitors are exposed to different radon exposures were used as theoretical approaches. Experimental methodology was conducted in a radon test chamber from Italy (MI.AM s.r.l.). Comparison results of both theoretical and experimental methodology are presented and discussed. One of the major results, among others, shows that the monitor material (conductive or non-conductive) does not influence the LR-115 response.

Monte Carlo simulation of semiconductor detector response to (222)Rn and (220)Rn environments

A new electronic radon/thoron monitor employing semiconductor detectors based on a passive diffusion chamber design has been recently developed at the Helmholtz Zentrum München (HMGU). This device allows for acquisition of alpha particle energy spectra, in order to distinguish alpha particles originating from radon and radon progeny decays, as well as those originating from thoron and its progeny decays. A Monte-Carlo application is described which uses the Geant4 toolkit to simulate these alpha particle spectra. Reasonable agreement between measured and simulated spectra were obtained for both (220)Rn and (222)Rn, in the energy range between 1 and 10 MeV. Measured calibration factors could be reproduced by the simulation, given the uncertainties involved in the measurement and simulation. The simulated alpha particle spectra can now be used to interpret spectra measured in mixed radon/thoron atmospheres. The results agreed well with measurements performed in both radon and thoron gas environments. It is concluded that the developed simulation allows for an accurate prediction of calibration factors and alpha particle energy spectra.

Detection of radon based on the lead-induced conformational change in aptamer T30695

A novel G-quadruplex sensor for the highly selective detection of accumulated radon and its decay products with low interference.