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During the manufacturing process in the cement industry, raw materials of different levels of natural radioactivity are utilized. In this study we present the radiological impact of cements as a building material and the different raw materials used in their manufacture. A total of 218 samples of raw materials and their end product cements were collected from the cement industry of Macedonia (The Former Yugoslav Republic) during the period 2005–2007. The specific activities, evaluated by gamma spectrometry analysis, showed the highest mean specific activity in fly ash ( 226 Ra, 107 ± 45 Bq kg −1 ; 232 Th, 109 ± 30 Bq kg −1 ; 40 K, 685 ± 171 Bq kg −1 ), which is used as a raw material. However, the final cement product usually has relatively lower activity compared with the activity of the raw material and the mean specific activity of the final cement products were lower ( 226 Ra, 42 ± 10 Bq kg −1 ; 232 Th, 28 ± 6 Bq kg −1 ; 40 K, 264 ± 50 Bq kg −1 ). The radium equivalent activity and the hazard index were calculated for each sample to assess the radiation hazard. The mean annual effective dose originating from the cements was found to be 111 ± 22 μSv y −1 , which is below the recommended EC limit of 300 μSv y −1 .

Activated charcoal was widely used in radon researches and mitigation applications because of good adsorption ability. In the paper, a simple model that can predict radon removal efficiency (η) for radon mitigation applications using flow-through activated charcoal system was developed based on the previous works. Experiments were conducted with a flow-through activated charcoal system to validate the model and study the influence of factors on η. The experimental results of η are consistent with the theory to within 4% at the flow rates of 1–3 L/min, but range from 2% to 14% at the flow rates of 4–5 L/min. The equilibrium time of radon linearly decreases with rising flow rate, and η decreases with rising flow rate. With moisture competing with radon for adsorption sites on the activated charcoal, radon reaches the equilibrium concentration more quickly than moisture does. As relative humidity increases, η decreases, but the radon equilibrium concentration increases. The values of η are bigger for those smaller particle sizes with the same type of activated charcoal. The results of this paper are useful for designing activated charcoal systems at indoor environmental conditions and predicting η for radon mitigation applications.

Timepix-based detectors have been deployed in a variety of mixed-field situations for dosimetry applications, such as Radon monitoring, evaluating propagating hadron therapy beams, and assessing radiation doses received by airline passengers and crewmembers. However, one of the most significant and complex achievements of Timepix-based detectors is their success in evaluating the incident charged particle fields in space radiation environments, both inside spacecraft and exposed to space with minimal shielding. This paper documents the applications of Timepix-based instruments for the purpose of determining the radiation doses experienced by astronauts. The incident neutron and to a much lesser extent, the dosimetric relevant photon component of that radiation field are not addressed in this review article. Timepix-based detectors have been deployed in a variety of mixed-field situations for dosimetry applications, such as Radon monitoring, evaluating propagating hadron therapy beams, and assessing radiation doses received by airline passengers and crewmembers. However, one of the most significant and complex achievements of Timepix-based detectors is their success in evaluating the incident charged particle fields in space radiation environments, both inside spacecraft and exposed to space with minimal shielding. This paper documents the applications of Timepix-based instruments for the purpose of determining the radiation doses experienced by astronauts. The incident neutron and to a much lesser extent, the dosimetric relevant photon component of that radiation field is addressed separately in this volume.

Signal stability is a key consideration when using luminescence dating techniques. The stability, or lifetime, of a signal is one of the factors determining the upper age constraint for luminescence dating, and it has been suggested that the signal being used for dating should have a lifetime at least ten times the age being dated in order to limit age underestimation to an upper loss of 5%. Accurate derivations of signal stability and associated kinetic parameters, such as trap depth and frequency factor, are also important parameters for constraining rock cooling histories in thermochronometric techniques. This paper aims to assess the reproducibility of lifetime determinations derived using isothermal decay measurements. Variability arising from changing the isothermal decay protocol used is tested. Simulating Arrhenius plot from fixed trap depth and frequency values shows that whilst trap depth can be relatively well constrained, significant variability in the frequency factor, hence signal lifetime, should be expected. This paper also uses luminescence signals measured using different wavelengths to better understand the impact of signal from non-fast quartz OSL components in lifetime calculations. The presence of contributions from non-fast OSL components in the initial part of the OSL signal can result in the lifetime being calculated from charge contributions from multiple traps, not solely the 325 °C TL peak, as has been previously assumed. This effect can be reduced however by stimulating luminescence signals with longer wavelengths to better isolate signal from the fast component.

The quest for new materials for thermoluminescence (TL) and optically stimulated luminescence (OSL) dosimetry continues to be a central line of research in luminescence dosimetry, occupying many groups and investigators, and is the topic of many publications. Nevertheless, it has also been a research area with many pitfalls, slow advances in our understanding of the luminescence processes, and rare improvements over existing materials. Therefore, this paper reviews the status of the field with the goal of addressing some fundamental questions: Is there a need for new luminescence materials for TL/OSL dosimetry? Can these materials be designed and, if so, are there strategies or rules that can be followed? What are the common pitfalls and how can they be avoided? By discussing these questions, we hope to contribute to a more guided approach to the development of new luminescent materials for dosimetry applications.

Previous calculations of the γ dose given to Risø Calibration Quartz (RCQ) were performed using mass absorption and mass attenuation coefficients. In this paper, we update the γ dose given to RCQ using Geant4 simulations and provide a comparison with three other γ sources in Denmark. We also show experimental evidence that the luminescence response to a137Cs γ irradiation is 4% higher than that resulting from a60Co γ irradiation for the same dose, confirming the suggestions of Autzen et al. (2021) based on simulations.

Organized by Working Group 6 "Computational Dosimetry" of the European Radiation Dosimetry Group (EURADOS), a group of intercomparison exercises was conducted in which participants were asked to solve predefined problems in computational dosimetry. The results of these comparisons were published in a series of articles in this virtual special issue of Radiation Measurements. This paper reviews the experience gained from the various exercises and highlights the resulting conclusions for future exercises, as well as regarding the state of the art and the need for development in terms of quality assurance for computational dosimetry techniques., Comment: 17 Pages, 6 Figures, submitted to Radiat. Meas

Beta Dose Rate heterogeneity is a recognized source of uncertainty when applying luminescence dating to heterogeneous samples, such as coarse crystalline rocks and clast-rich sediments. Simulations have shown that a combination of a heterogeneous distribution of minerals and radioactive elements can lead to complex dose distributions, overdispersion and potentially to bias in equivalent dose determinations. However setting realistic conditions for such simulations remains difficult, and there are at present only a few experimental validation cases for such simulated systems. Project ADDEM is investigating means of linking Monte Carlo simulations of dose rate to specific minerals with direct observations using high sensitivity phosphor plates and laser scanning imaging systems in combination with phase mapping. To overcome some of the limitations of autoradiographic imaging of low level beta dose distributions work has been undertaken using Landauer alumina OSL phosphor screens in combination with a laser scanning system developed at the Scottish Universities Environmental Research Centre (SUERC). Preliminary excitation spectra, emission band characterisation and time resolved measurements were undertaken, confirming the potential to recording low doses using asynchronous stimulation at 635 nm coupled with blue band detection. Taking advantage of the slow decay of the luminescence signal the scanning equipment has been configured for pulsed stimulation and asynchronous detection to maximise signal to background ratios. Exploratory work was calibrated using a 60Co facility capable of calibrating doses in the µGy to mGy range. A series of powdered granulite/basalt mixtures of known mean activity and dose rate (Dr) have also been used to calibrate the phosphor screens. To reduce background levels during autoradiographic signal accumulation rock slices are being exposed in the Zeplin shield of the STFC Boulby Underground Laboratory, in an environment which is essentially free from cosmic ray muon background.\ud Simulations have been conducted providing preliminary deconvolution parameters in order to either reconstruct the beta dose rate (β Dr) distribution received by the grains in the sample, or retrieve the radioactive element distributions in the minerals of the sample, providing the data required for representative simulations of β Dr.\ud This paper outlines the spectroscopy and sensitivity verification of the autoradiography system, confirming its prospects for measuring spatially resolved β Dr distributions with single pixel lower detection limit of 130 µGy and spatial resolution of 150 µm. Prospects are outlined.

In neutron fields including neutron energies above 20 MeV a conventional neutron dosimeter is not suitable for measurements of neutron personal dose equivalent, Hp(10), over the whole energy range. Therefore, for such fields an electronic neutron dosimeter has been developed recently at Helmholtz Zentrum Munchen (HMGU). In general, neutron dose measurements performed with this dosimeter at neutron energies below 2 MeV show an accuracy of about 30% [1]. Here we report the use of this dosimeter at the CERN-EU high-energy Reference Field (CERF) facility in Geneva, Switzerland. At this facility the available neutron fields include neutrons with energies below, but also above 20 MeV. In the present paper, personal dose equivalent (Hp(10)) values obtained with the ELectronic neutron DOsimeter (ELDO) are compared to neutron personal dose equivalent (Hp(10)) values obtained with the HMGU extended-range Bonner Sphere Spectrometer, and to reference values from FLUKA Monte Carlo simulations provided by CERF. It is shown that for continuous neutron spectra as those at CERF behind concrete shielding or secondary neutrons from cosmic rays, the dosimeter results are satisfactory for radiation protection purposes. However, in neutron fields including neutrons above about 7 MeV, where the major neutron dose contribution is from neutrons between 10 keV and several MeV (like those at CERF behind iron shielding), the doses provided by ELDO might be too small and care must be taken in interpreting the results.

The lower operation limit of common tissue equivalent proportional counters (TEPCs) is about 0.3 μm in simulated site. On the other hand, the pattern of the particle interactions at the nanometric level, which has a correlation with the radiation induced damage on the DNA, is measurable by only three instruments worldwide. In order to fill this gap, a novel TEPC capable of simulating site sizes down to 25 nm was designed and constructed. Its response was characterized with gamma, neutron and carbon beams and the capability in measuring microdosimetric spectra at 25 nm was demonstrated. The present paper aims at describing a further characterization of this TEPC by simulating with the Monte Carlo FLUKA code the microdosimetric spectra measured with a carbon beam. Since the sensitive volume of the TEPC has an unconventional shape, a study on the chord length distribution for the adopted irradiation set-up was performed and compared with the analytical one. The results show a good agreement between the experimental data and the FLUKA simulations, showing that this code is capable of reproducing microdosimetric spectra of a carbon beam down to 25 nm in simulated site.

An intercomparison of microdosimetric and nanodosimetric quantities simulated Monte Carlo codes is in progress with the goal of assessing the uncertainty contribution to simulated results due to the uncertainties of the electron interaction cross-sections used in the codes. In the first stage of the intercomparison, significant discrepancies were found for nanodosimetric quantities as well as for microdosimetric simulations of a radiation source placed at the surface of a spherical water scoring volume. This paper reports insight gained from further analysis, including additional results for the microdosimetry case where the observed discrepancies in the simulated distributions could be traced back to the difference between track-structure and condensed-history approaches. Furthermore, detailed investigations into the sensitivity of nanodosimetric distributions to alterations in inelastic electron scattering cross-sections are presented which were conducted in the lead up to the definition of an approach to be used in the second stage of the intercomparison to come. The suitability of simulation results for assessing the sought uncertainty contributions from cross-sections is discussed and a proposed framework is described., 23 pages, 7 figures, 5 tables plus 3 supplementary figures

One of the most important lessons learned from the Fukushima Daiichi Nuclear Power Plant accident is that direct (in vivo) measurements of thyroid exposure to radioiodine (mainly, 131I) in the affected populations should be initiated in a timely manner. Furthermore, the existing commercial detectors are not necessarily suitable for the measurement of young children, who are especially vulnerable to radiation exposure and therefore important to screen. This paper presents the development of a new thyroid monitor for such measurements and the results from phantom-based experiments. The monitor has two unique probes having multiple high-energy-resolution type Gd3(Al,Ga)5O12(Ce) (GAGG) detectors that can be placed directly on the young subject's anterior neck. The crystal size of the GAGG detector is 1 cm3, and a probe consisting of a 4 × 1 or 4 × 2 detector array can be selected depending on the subject's body size. The thickness of the 4 × 1 array probe is 24 mm, which is less than that for a conventional NaI(Tl) survey meter having a crystal 1 inch in diameter and 1 inch long (38 mm). Experimental and computational calibrations of the new monitor using existing and virtual phantoms allowed us to determine the full energy peak efficiency for the 131I thyroid contents of different age groups from 3-mo-old to 10-yr-old and minimum detectable activity (MDA) values under various conditions. As a result, the attainable MDA for subjects age ≤5 years under a normal background level (∼0.05 μSv h−1) was found to be ∼30 Bq, which was low enough to identify children with thyroid-equivalent doses over 10 mSv up to about 25 days after the 131I intake. Our new monitor would be useful in direct thyroid measurements for vulnerable young children following a large nuclear accident.

The first unmanned flight of the Orion Multipurpose Crew Vehicle (MPCV) was successfully completed on December 5, 2014. The total mission duration was 4.5 h, and the EFT-1 trajectory consisted of a high apogee (∼6000 km, 28.6° inclination), high eccentricity orbit through the Van Allen belts. Radiation measurements on Orion included a novel Battery-operated Independent Radiation Detector (BIRD) based on Timepix hybrid pixel technology, luminescence dosimeters (LiF:Mg,Ti, 6LiF:Mg,Ti, 7LiF:Mg,Ti, CaF2:Tm and Al2O3:C) and plastic nuclear track detectors (CR-39). This paper will discuss the advantages of the BIRD instrument with respect to analysis of the environment changes along the flight trajectory using the time stamp tracking capability of the pixel detector. In addition, a dosimetry comparison between the active BIRD instrument and the passive radiation area monitor (RAM) detectors in terms of mission absorbed dose.

Authorities responding to nuclear security events have to be prepared for a situation in which a neutron source or nuclear material is out of regulatory control. In such a situation, handheld neutron detectors are used to search for neutron sources or nuclear material, during either an overt or a covert search. These detectors are also used to support the initial threat assessment, radiation protection at the scene and the initial characterisation of the source. Long range neutron detection, i.e. detection several tens of meters from the source, referred to here as “stand-off” detection, is of importance to nuclear security. An estimate of the neutron source strength is especially important for the initial threat assessment. However, the neutron dose rate and the neutron response are strongly dependent on the distance between the detector and the source and on the surrounding environment. These influences should be considered when estimating the neutron source strength from initial measurements. In this paper the variation of the neutron dose rate and the neutron count rate with distance from a neutron source in different, representative environments was determined. Monte-Carlo simulations were carried out in order to gain more understanding of the results. In addition, the variation of the neutron dose rate with distance from a neutron source in different surroundings is summarized in order to assist the initial threat assessment at the scene of a nuclear security event.

Scintillator based coded-aperture imaging has proven to be effective when applied for X- and gamma-ray detection. Adaptation of the same method for neutron imaging has resulted in a number of propitious systems, which could be potentially employed for neutron detection in security and nuclear decommissioning applications. Recently developed scintillator based coded-aperture imagers reveal that localisation of neutron sources using this technique may be feasible, since pulse shape discrimination algorithms implemented in the digital domain can reliably separate gamma-rays from fast neutron interactions occurring within an organic scintillator. Moreover, recent advancements in the development of solid organic scintillators make them a viable solution for nuclear decommissioning applications as they present less hazardous characteristics than currently dominating liquid scintillation detectors. In this paper existing applications of coded-apertures for radiation detection are critically reviewed, highlighting potential improvements for coded-aperture based neutron source localisation. Further, the suitability of coded-apertures for neutron imaging in nuclear decommissioning is also assessed using Monte-Carlo modelling.

1300 or 1400 °C pre–sintered Al/Ce/Mg:SrHfO 3 and Al/Ce:SrHfO 3 ceramics were prepared by the Spark Plasma Sintering (SPS) in order to search for a new scintillation material with a high–effective atomic number(Z eff ) and good light output. The SrHfO 3 has a high Z eff of 60, and high gamma–ray detection efficiency is expected. Meanwhile it has a high melting point of over 2500 °C, and single crystal is hard to be grown. On the other hand, high melting materials can be prepared as ceramics, and the SPS method is a simple process to fabricate the ceramics within a few hours. Thus, we prepared the samples using the SPS method, and their optical and scintillation properties were investigated. We found that Al/Ce/Mg:SrHfO 3 and Al/Ce:SrHfO 3 ceramics had an emission wavelength at around 400 nm originating from 5d–4f transition of Ce 3+ . Moreover, Al/Ce/Mg:SrHfO 3 pre-sintered at a temperature of 1400 °C had a light output of approximately 5,000 ph/MeV. In this paper, the light output of Mg-co-doped samples was improved compared with the Mg-free ones. The light output also depends on the pre-sintering temperature.

In this paper we investigate the light response to fast neutrons and estimate the pulse height resolution of a deuterated liquid organic scintillator, EJ-315, considering the detector's non-linear light response to gamma-rays. Initially, collision data and a neutron beam trigger are recorded in coincidence mode, and incident neutron energy is calculated with a time-of-flight technique. Fast neutrons are further discriminated from gamma-ray background based on the scintillation material decay patterns using a pulse shape discrimination algorithm. A light response matrix composed of multiple neutron energy and their corresponding light outputs is derived. The pulse height resolution property of the EJ-315 is characterized utilizing the derivatives of the pulse height distributions with corrections of the measurements setup uncertainties. Additionally, the EJ-315's pulse height resolution is also characterized by comparing the smoothed derivatives of quasi-monoenergetic neutron pulse height distributions, given by the Peierls-formula-based analytic model, to match the measurement data. Results show rather consistent 10–13% pulse resolution for mono-energetic neutrons with kinetic energy above 2 MeV. The resolution decreases slightly with an increase in neutron energy indicating the improved resolution performance of EJ-315 in the higher energy events.

Identification of neutron sources is of interest in several fields, such as homeland security or basic nuclear physics. Organic scintillators offer the possibility to unfold fast-neutron energy spectra. Since organic scintillators are sensitive to neutrons and gamma-rays, a method to discriminate these two types of particles is required. This paper is focused on investigation of the discrimination properties of the filter method by using a new procedure. We compare the results of an experimental filter method to a digital pulse-shape discrimination (PSD) method based on charge integration. In addition, these methods are compared to the simulation results obtained with the MCNPX-PoliMi code. The experimental and numerical investigations were performed with a 252 Cf spontaneous-fission neutron source. The integration of the number of counts gave the relative differences between the experimental filter and digital PSD neutron pulse-height distributions (PHDs) and simulated PHDs less than approximately 5% in the range between 60 keVee and 1.715 MeVee of light output. Above 1.715 MeVee, the PSD method has advantages over the filter method, due to the filter method having significantly worse counting statistics. The results show that the filter method has potential for robust neutron measurements when the PSD method cannot be applied, such as for ‘old’ organic plastic scintillators without PSD capability.

The aim of this paper is to characterize the IRSL response of rare earth doped CaF2 and co-doped with Al or Li, produced by the solution combustion synthesis (SCS). The results showed a high intensity of the infrared optically stimulated luminescence (IRSL) response for the samples of CaF2 doped with Tb and co-doped with Li. For the samples of CaF2 doped with Ce and co-doped with Li present better IRSL response than the samples co-doped with Al. It was also observed that the samples of CaF2:Ce,Li present a high fading with 50% reduction of the IRSL signal in a period of 60 min. In case of the CaF2:Tb,Li there is no significant fading during this period. For clinical dosimetry the fast fading of the dosimeter is not adequate. However, this feature can be exploited for other applications such as tamper-proof passive systems that detect and timestamp the movement of undeclared nuclear materials, by the estimation of the OSL response of materials with different fading rates.

The first Medipix chip which aimed at permitting single photon counting on a sizable matrix of pixels was developed in the mid-1990's. In the following 20 years two families of chips have evolved from that initial effort. The Medipix photon counting family of chips comprises Medipix, Medipix2 and Medipix3. A 4th generation chip, Medipix4, is under development. The Timepix chips were initially more aimed at single particle detection and that family comprises Timepix, the most recent Timepix2 chip (introduced in this Special Issue) and Timepix3. The 4th generation Timepix4 is also under development and a first version will be produced in 2019. This paper seeks to provide a brief introduction to the various members of the Medipix family and provide references to more detailed descriptions already available in the literature.

This paper explores the attenuation of beta and gamma dose rate in a radioactive and in an adjacent inert layer for K, Th and U, individually, using Geant4 simulations. The simulated beta dose rate attenuation cannot perfectly be described by a single exponential function, thus the updated attenuation coefficients were obtained using two exponential functions with intercepts related to the different slopes. Attenuation coefficients and intercepts are provided in the manuscript. The newly obtained beta dose rate attenuation coefficients differ from the previously published values by a factor of 2, which results in a larger attenuation of the beta dose rate, so that the infinite matrix dose rate is reached at ~2 mm into the sediment and at ~1.5 mm into a rock. The new gamma dose rate attenuation coefficients are in good agreement with previously published literature and it is shown that the infinite gamma dose rate is reached at 300 mm in wet sediment with a density of 2 g cm−3.

Existing infrared photoluminescence (IRPL) systems have used pulsed infrared stimulation (~830 nm) and measured IRPL emission (at 880 or 955 nm) using time resolved data collection with photomultipliers. Breakthrough of the infrared stimulation light overwhelms the IRPL, but the delayed emission during the laser-off period has been used instead. This paper describes a system for measurement of the IRPL signal from single sand-sized grains of feldspar. The attachment uses an electron-multiplying charge-coupled device (EMCCD) imaging system, and has two innovations that make it possible to use such a detector to obtain IRPL data. First, the optical detection system has been designed to minimise stray light and maximise the efficiency with which filters reject the stimulation light. This acts to reduce, but not eliminate, the breakthrough. Second, by placing the sample to be measured in a clearly defined sample grid, the spatial resolution provided by the EMCCD has been used to differentiate between regions of the image where IRPL is emitted and adjacent regions where only breakthrough is expected. This allows quantification of the breakthrough and effective subtraction to isolate the IRPL signal from the grains of interest. The attachment has been used to measure IRPL from single sand-sized grains of feldspar from an aeolian dune from New Zealand. A 1W UV LED (365 nm) is also added to the system and this is effective at resetting the IRPL signal, permitting a single aliquot regenerative dose (SAR) protocol to be used to measure equivalent dose (De). Measurement of a known laboratory dose (104 Gy) demonstrates the reproducibility of the attachment, with no overdispersion observed in the resulting single grain De values. The recovered dose is within 10% of the given dose. The natural IRPL signal yields De values from single grains with low overdispersion (22%) and giving a weighted mean value (103 ± 5.8 Gy) that is consistent with that obtained using post-IR IRSL measurements (105 ± 3.8 Gy). The attachment described here provides IRPL measurements on single grains suitable for exploring the potential of this novel and exciting signal for dating geological sediments.

The present study aims at investigating several key aspects of ESR dose reconstruction of quartz grains based on the analysis of the Ti-center: (i) the evaluation of the ESR intensity, (ii) its impact on measurements precision, and (iii) the potential of various fitting functions to describe the behavior of the signal with the radiation absorbed dose. In contrast with the Al center, the various Ti centers have quite low ESR signal intensities. It is thus crucial to adapt the experimental conditions for the optimization of the signal-to-noise ratio and to perform repeated measurements in order to take into consideration the uncertainty associated to angular dependence of the signal as well as day-to-day variations. Several options (named A to E) for evaluating the ESR intensity of the Ti–Li and Ti–H centers are explored and some of them yield too much experimental uncertainty (e.g. options C and E) and are apparently not suitable for accurate ESR dosimetry. In contrast, options A and D usually provide similar equivalent dose (DE) results and can be used together for assessing the dose absorbed by the Ti–Li center. Our results show a systematic non-monotonic behavior of the ESR signal of the Ti center with the dose, which raise some questions about the suitability of the single saturating exponential (SSE) function that is classically used in ESR dating. Consequently, we explored the potential of other functions that can describe the “radiation bleaching” phenomenon observed at high doses. We recommend the use of a specific fitting function (called Ti-2 in the present paper) previously proposed by Woda and Wagner (2007) for any dose reconstruction, and define some criteria to ensure a good fitting. The SSE function provides DE results that are, in most cases, relatively consistent with those derived from the Ti-2, suggesting that the Ti centers apparently follow a SSE behavior up to, at least, 6.0–6.5 kGy However, the reliability of the DE values obtained with the SSE seems quite dependent on the accuracy of the ESR intensities of the increasing domain of the dose response curve. We also recommend the definition of criteria to check the reliability of the DE results.

This paper presents a method for a small, inexpensive mobile robot equipped with a single high resolution scintillation detector to quickly survey an area and convey information about local sources of gamma radiation to a remote human operator. This is achieved by surrounding the detector with a lead sheath that blocks all gamma-rays except those incident along the detector's axial direction. A 180° horizontal scan is performed by rotating the detector and a directional profile of gamma radiation is constructed. In addition, a 180° visual panorama of the local area is assembled using a camera mounted on the detector. A plot of the detector count rate versus angle is then overlaid on top of the visual panorama and visible peaks clearly indicate the direction of local gamma radiation sources. Measuring the energy spectrum of gamma-rays in each direction produces a 2D count frequency histogram where distinct peaks indicate the energy and direction of local gamma-ray sources allowing the identification of different radio-isotopes. The mobile robot can use the peaks as goal directions and autonomously move towards gamma-ray sources.

This paper presents selected optically stimulated luminescence properties of Lu2SiO5:Ce single crystalline films grown using Liquid Phase Epitaxy technique. Comparison of continuous wave optically stimulated luminescence decay curves under blue and green light stimulation is shown. The dose response characteristic is found to be linear in the studied range from 100 μGy to 1 Gy. Analyses of the linearly modulated optically stimulated luminescence signal enabled establishing of the photoionization cross sections for blue light (470 nm). Bleachability and thermal stability of CW–OSL signal are discussed, as well as preliminary results of the fading study.

Rem-Counters are widely used in radiation protection practice for environmental neutron detection. They are usually based on both an active and a passive thermal neutron detector surrounded by a hydrogenate moderator designed to obtain a response function as close as possible to the H *(10) curve. Inclusion of high Z material is also used to extend the response function up to 1 GeV of neutron energy. Recently a dual detector Rem-Counter, both active and passive, was proposed by Agosteo et al. (2010) . The present paper focuses on the passive version that is based on a CR-39 track detector coupled to an enriched 10 B converter. A technique was developed for the track analysis based on the measurement of the mean LET of the charged particles produced by the neutron reaction on 10 B that has proven to be very effective in the background reduction. Moreover the simulated response function of the Rem-Counter was compared with the experimental results obtained with irradiations carried out with monoenergetic neutron beams, showing a quite good agreement.

Electron Paramagnetic Resonance (EPR) spectroscopy with tooth enamel is a widely used method of dosimetry. The accuracy of EPR tooth dosimetry depends on the spectrum processing procedure, the quality of which, in its turn, relies on instrumental noise and the signals from impurities. This is especially important in low-dose evaluation. The current paper suggests a method to estimate the accuracy of a specific spectrum processing procedure. The method is based on reconstruction of the radiation-induced signal (RIS) from a simulated spectrum with known RIS intensity. The Monte Carlo method was used for the simulations. The model of impurity and noise signals represents a composite residual spectrum (CRS) obtained by subtraction of the reconstructed RIS and the native background signal (BGS) from enamel spectra measured in HMGU (Neuherberg, Germany) and IMP (Yekaterinburg, Russia). The simulated spectra were deconvoluted using a standard procedure. The method provides an opportunity to compare the simulated "true" RIS with reconstructed values. Two modifications of the EPR method were considered: namely, with and without the use of the reference Mn2+ signals. It was observed that the spectrum processing procedure induces a nonlinear dose response of the reconstructed EPR amplitude when the height of the true RIS is comparable with the amplitudes of noise-like random splashes of CRS. The area of nonlinearity is below the limit of detection (DL). The use of reference Mn2+ signals can reduce the range of nonlinearity. However, the impact of the intensities of CRS random signals on nonlinearity is two times higher than the one observed when the reference signals were not used. The reproducibility of the software response is also dependent on both the amplitude of the CRS and the use of a reference signal, and it is also two times more sensitive to the amplitude of the CRS. In most EPR studies, all of the data are used, even those for which the dose value is lower than the DL. This study shows that low doses evaluated with the help of linear dose-response can be significantly overestimated. It is recommended that linear dose response calibration curves be constructed using only data above the DL. Data below the DL should be interpreted cautiously. © 2014 Elsevier Ltd. All rights reserved.

The paper reports on a semi-automatic method for the detection and analysis of ion-etch pits generated on Solid State Nuclear Track Detectors (SSNTD) of the CR39 type. The CR39 detectors have been exposed to the elastically scattered Cun+ ions on a 50 nm Au layer deposited on a silicon substrate. After irradiations, foils have been chemically etched for 2 h in a 6.25 M NaOH solution to develop the ion-induced latent tracks. The detectors' surfaces have been analysed by Optical Microscopy (OM) and studied with the proposed method based on the measurements of both diameter and mean gray value of the ion-etched pits. The results are motivated by the future applications of these polymeric foils in the detection of charged particles in “harsh” environments, characterized by high dose and high radiation damage, e.g., in fusion experiments or in the diagnostic of plasma generated by lasers. A strong correlation between tracks’ characteristics (diameter and grayness) and the energy of the backscattered Cu ions has been obtained and empirical relationships between them are presented.