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Nuclear track methodology (NTM), is employed to analyze PADC detectors response to different energetic ion beams. Due to the passive device linearity response to heavy ions with LET-value > 30 keV μm−1, they are employed in several fields e.g. nuclear industry, medical, environmental radiation and aircraft dosimetry. To further improve application, PADC-detectors were irradiated by beams of 4He (150 MeV nucleon−1), 12C (390 MeV nucleon−1) and 56Fe (465 MeV nucleon−1), in relatively low-dose range ≤ 1 mGy. Results provided, through etched track analysis, valuable information of interest for NTM when high LET ionizing radiation is involved. [ABSTRACT FROM AUTHOR]

Abstract: The microscopic process taking place during chemical etching is described in terms of a dynamic framework governed by capillary condensation. The aim is to obtain physical information on how the cone shaped tracks with curved walls evolve during chemical etching under a close examination of first principles. The results obtained with the proposed theory are compared with published values to establish their range of validity. [Copyright &y& Elsevier]

Abstract: Diffusion of alpha emitter radon progeny inside a cylindrical diffusion chamber was simulated. In the simulation of atomic movements, we took into account the random nature of the diffusion direction and the decay process. The alpha emitter distributions in volume, lateral wall and top cover of a 6.0cm height diffusion chamber for different diameters were determined. Results show non-uniform distribution of radon progeny. As chamber diameter increases, the tendency of radon progeny is to accumulate in central regions of the chamber volume and inner wall ( and ). Depending on chamber diameter and detector size, non-uniform distribution of radon progeny deposited on SSNTs surface can be achieved if the detector is horizontally located at the bottom. The fraction of surface where progeny are deposited diminishes as chamber diameter increases. Due to the relatively short half-life, for diameters larger than the assumed height its subsequent atoms decay in air before their deposition on chamber wall. The form in which radon progeny is distributed in volume and walls of chamber can affect the quantity and distribution of tracks in detector. [Copyright &y& Elsevier]

Abstract: A new method, based on Digital Holographic Microscopy (DHM), to visualize and to analyze etched tracks in SSNTD has been developed. The proposed method is based on the possibility of the digital holography to perform whole reconstruction of the recorded wave front, so that phase and intensity distribution at a plane located between the object and recording plane and along the reconstructed image of the object can be determined. In a DHM system, the back focal plane of the lens can be reconstructed so that complex amplitudes of the Fraunhofer diffraction of light distribution across the object can be known. With the knowledge and manipulation of the components of this plane is possible to design different methods of image analysis. In this paper, the DHM method was applied to determine the track parameters in CR-39 detectors, showing that most of studies carried out with Confocal Microscopy and Atomic Force Microscopy could be also done, with the sufficient exactitude and precision, but in a simpler and more economic way. The developed microholographic method provides a new alternative procedure that overcomes the current techniques at least in technological simplicity. [ABSTRACT FROM AUTHOR]

Abstract: Exposure to indoor radon and suspended particulate matter (SPM) is considered a high risk in lung cancer aetiology. In this paper indoor radon and SPM concentration measurements and their correlations, associated with lung cancer cases are given. Mexico City suffers high concentration of SPM as well as other photochemical pollutants such as ozone. During the last decade in Mexico City, radon and SPM have been monitored. The indoor radon measurements were done using the Nuclear Track Methodology, basically the close-end-cup device with polyallyldiglycol carbonate as detector material, followed of an established chemical etching protocol, and automatic digital image analyzer system for counting. SPM size and concentration were obtained from monitoring stations located along the city. The results show that the central–north part of Mexico City has a large concentration of SPM and the vulnerable population (older than 65 years and younger than 14 years) is located essentially in the same region. In this area, a large number of lung cancer cases were found, even if indoor radon levels were below the recommended limits. [Copyright &y& Elsevier]

Abstract: Passive nuclear track detectors in the study of multi fragmentation and compound nucleus fission in the fusion reaction 54Cr+ 208Pb, leading to composite systems with Z =106 is given. Results indicate that mostly nuclear tracks are related to fragments with low atomic number and less than 11% to beam like particles in opposition to the expected distribution. [Copyright &y& Elsevier]

Abstract: The results of radon concentration measurements inside of the Gabriel caves of Mexico, during three consecutive two-month periods covering almost three seasons, are reported in the present work. The radio-ecological importance of this site is related to the radon and its concentration-dynamic behavior in the cave. Further interest in radiation safety motivated this initiative since routine biological field work is done, with people spending long periods of time there. CR-39 passive nuclear track detector was chosen for this survey. Radon concentration levels decrease during the rainy season and show different values depending on the ventilation and geometeorological structure. Measured values range between 956 and , an indication that radon doses may exceed the allowed values for workers. This project is part of a larger study of indoor radon alpha emitters in Mexican caves. [Copyright &y& Elsevier]