Radiation Measurements Research Papers - Academia.edu (original) (raw)

2025, Journal of Physical Chemistry & Biophysics

International studies of radon indoors and in workplaces have shown significant radiation dose burden of the general population due to inhalation of radon ( Rn) and its short-lived progeny ( 218 Po, 214 Pb, 214 Bi, 214 Po). As far as atmospheric radon concerns, 222 Rn, is not necessarily in equilibrium with its short-lived progeny. For this reason, radon's equilibrium factor F was solved graphically as a function of the track density ratio R=T B /T R , namely of the ratio between the recordings of cup-type and bare CR-39 detectors. T B was computed through special Monte-Carlo codes which were implemented for the calculation of the efficiency of bare CR-39 polymers, regarding their ability in sensing the alpha particles emitted by the decay of radon and its short-lived progeny. For a realistic approach, Monte-Carlo inputs were adjusted according to actual experimental concentration measurements of radon, decay products and F of Greek apartment dwellings. Concentration measurements were further utilized for the calculation of the unattached fraction, f p , in terms of Potential Alpha Energy Concentration (PAEC, defined as the sum of the initial -per volume -energies of all alpha particles emitted due to the decay of radon and its short-lived progeny that are present within a certain amount of air). This was employed for the calculation of F in terms of ratio (A 4 /A 0 ), where A i represents the activity concentration of radon (i=0) and 214 Po (i=4) respectively. Measured and calculated values of F were plotted versus R. The results were fitted and checked with model's predictions.

2025, Research Journal of Applied Sciences, Engineering and Technology

The primary objective with radiation sources and facilities is the protection of both radiation workers and the general public. The biological shields of the Secondary Standard Dosimetry Laboratory of the Radiation Protection Institute (RPI) Ghana had been evaluated for a collimated isotropic cesium-137 source for calibration purpose using MCNP5 code. The dose rate at supervised areas ranged from 0.57 to 8.35 :Sv/h and 0.26 to 10.22 :Sv/h at control areas when the source was panoramic. When the source was collimated, the dose rate ranged from 0.05 to 0.30 :Sv/h at supervised areas and 0.23 to 8.88 :Sv/h at control areas for 22.2 GBq of the cesium-137 source. The scatter contribution from the surfaces of the walls and roofs were also accounted for. The scatter radiation in the room decreased to 400 :Sv/h when the source was first collimated and to 3.5 :Sv/h when the source was further collimated. These results agreed quite well with experimental measurement. To effectively protect the staff, a narrow beam of 1.2 cm diameter which was defined at 1.0 m by the total surface of the ISO slab phantom was recommended to reduce the dose rate to less than 1.5 :Sv/h outside the calibration bunker even when the current activity is doubled. It was concluded that the 4.7 cm diameter of the existing narrow beam should be decreased to 1.2 cm by further collimation of the beam.

2025, Nuclear Technology and Radiation Protection

Thermoluminescent MCP-N detectors based on LiF:Mg,Cu,P are by about 2 orders of magnitude more sensitive than TLD-100 detectors based on conventional LiF:Mg,Ti, which makes it possible to use them in short-term monitoring of ionizing radiation in the environment (e. g., over a two-week period, rather than over 3-12 months). We describe the properties of MCP-N detectors and methods of their application in environmental monitoring. The system was tested in short and long-term exposure periods at 100 sites around Krakow region. MCP-N detectors were then applied to measure variation of radiation dose rate at four selected villages in Serbia, where depleted uranium ammunition was deployed in 1999. Together with short-term thermoluminescent dosimetry, in situ measurements using proportional counters were per formed in order to assess the range of variation of natural radiation background in these villages. The mean terrestrial kerma dose rate in these villages was found to vary between 85...

2025, Radiation Measurements

Time-resolved infra-red stimulated luminescence (TR-IRSL) technique enables an understanding of the dynamics of trapped electrons after IR excitation in the band-tail states of feldspar. This work intends to study the underlying physical mechanism of IRSL production. TR-IRSL studies were carried out on four feldspar mineral specimens of variable chemical composition and structural state. Assuming the IR excited trapped electrons make random walks in the band-tail states and recombine by tunnelling dynamically, hopping time is derived from the OFF time data of TR-IRSL. This analysis indicates that the hopping time decreases with stimulation temperature. Using Einstein diffusion equation, hopping probability is computed and is shown to obey the equation describing variable range hopping mechanism of Mott kind. Mott's parameters (hopping length and hopping energy) are then derived. Hopping length decreases with stimulation temperature whereas hopping energy increases with temperature. The average hopping length and energy are in the range of 11e18 Å and 45e55 meV respectively and the diffusion constant is estimated to be in the range of 10 À10 e10 À9 cm 2 s À1 for all the feldspar samples.

2025, Journal of Luminescence

Time-resolved infrared-stimulated luminescence (TR-IRSL) signals from feldspar samples have been the subject of several recent experimental studies. These signals are of importance in the field of luminescence dating, since they exhibit smaller fading effects than the commonly employed continuous-wave infrared signals (CW-IRSL). This paper presents a semi-empirical analysis of TR-IRSL data from feldspar samples, by using a linear combination of exponential and stretched exponential (SE) functions. The best possible estimates of the five parameters in this semi-empirical approach are obtained using five popular commercially available software packages, and by employing a variety of global optimization techniques. The results from all types of software and from the different fitting algorithms were found to be in close agreement with each other, indicating that a global optimum solution has likely been reached during the fitting process. Four complete sets of TR-IRSL data on wellcharacterized natural feldspars were fitted by using such a linear combination of exponential and SE functions. The dependence of the extracted fitting parameters on the stimulation temperature is discussed within the context of a recently proposed model of luminescence processes in feldspar. Three of the four feldspar samples studied in this paper are K-rich, and these exhibited different behavior at higher stimulation temperatures, than the fourth sample which was a Na-rich feldspar. The new method of analysis proposed in this paper can help isolate mathematically the more thermally stable components, and hence could lead to better dating applications in these materials.

2025, Applied Radiation and Isotopes

Glow peak at 608 K in Mn doped Barite. Minimum detectable dose of 1.45 70.12 mGy with 35% fading in 30 days storage time. Reproducible TL signal within 75%. Suitable for retrospective dosimetry and geochronology of young deposits... more

2025, Physical Review C

A multifractal Bernoulli distribution, which appears by a natural way at some morphological phase transition, is introduced and it is shown that this distribution gives a good fit to the data obtained in laboratory experiments and in a numerical simulation of the particle multiproduction in the heavy ions collisions at high energies. ͓S0556-2813͑99͒03801-7͔

2025, Radiation Measurements

Electron spin resonance investigations on an electron-beam irradiated solid state nuclear track detector, based on cellulose nitrate (KODAK LR-31 l), are reported. The nature of free radicals induced in polymers by irradiation is discussed. The dependence of resonance spectral parameters on irradiation times, as well as on storage time and temperature, is studied. The experimental results are related to the stability of latent tracks and it is concluded that the free radicals induced by irradiation are located within the latent tracks. We have shown that both latent track and free radical thermal fading obey an Arrheniuslike dependence, with the same activation energy.

2025, Elsevier eBooks

lap along the ion range resulting in a continuous core of heavily damaged material. Differential thermal annealing experiments allow to discriminate between tracks produced by various subgroups of Ultraheavy ions (Z > 31) in ancient... more

2025, Nuclear instruments and methods in physics research

2025, International Journal of Radiation Applications and Instrumentation. Part D. Nuclear Tracks and Radiation Measurements

Using the new dyed ECE track (DYECET) method, tracks are densely dyed in polymers like polycarbonate (PC) and CR-39 forming high photon absorbent sites for spectrophotometry or other applications. By efforts made to bypass the acid treatment, different color DYECETs were developed with or without acid treatment. However, the UV absorbency was low and constant in foils not being acid treated. In this paper, the results as well as some phenomenological conclusions are presented and discussed.

2025, International Journal of Radiation Applications and Instrumentation. Part D. Nuclear Tracks and Radiation Measurements

The effects of pre-ething time (PET) or duration of etching of fast-neutron-induced-recoil tracks in CR-39 in 6N KOH at 60 oc on electrochemical etching neutron characteristic responses; i.e. sensitivity and mean recoil track diameter (MRTD) versus KOH normality up to 18N are investigated in this paper. Six sets of responses for PETs of O, I, 2, 3, 4, and 5 hours were obtained by using our new multi-chamber ECE (MCECE) system which reduced total operation time to about 6% of the time usually required when single-chamber ECE systems are used. The sensitivity response for zero PET showed a broad plateau and a high sensitivity low-LET peak around 16N. By increasing PET, another peak was also developed around 5N leading to "double-humped L' responses with two maximums around 5N and 16N, and a minimum around 1IN. On the other hand, the MRTD responses for all PETs studied showed the same general trend with maximums aroundllN. In this paper, shape of tracks under different conditions are also investigated, new optimum conditions such as KOH concentrations of 5, II, and 15N at 25 oc, with or without pre-etching, are recommended for tracks of lower-LET recoils including possibly protons, and alpha particle tracks over a broad energy range, and the efficiency of the MCECE system is also demonstrated.

2025, International Journal of Radiation Applications and Instrumentation. Part D. Nuclear Tracks and Radiation Measurements

2025, Nuclear Tracks and Radiation Measurements (1982)

The effects of alpha energy, track density, and etching duration on the electrochemical etching (ECE) amplification of alpha and recoil tracks in polycarbonate were studied using a mixture of 15g KOH + 40g C2H50H + 45g H20 at 25 °C applying 32 kV/cm at 2 kHz. Complex families of responses were obtained and two track groups were observed; smaller tracks due to energy losses of alpha particles themselves showing Bragg-type responses, and larger recoil-type tracks due to alpha-induced recoils from Rutherford-type scattering with light nuclei of carbon and oxygen. A significant reduction in both efficiency and mean track diameter with increase in track density was found and its effect on the responses was demonstrated. Systematic changes on the responses around the Bragg peak occurred by changing the track density and etching duration. The results are discussed with recommendations on considering the formation of recoils on alpha quality factor and considering track density as an affecting parameter for any precise and accurate dosimetric, spectromet~±c and parametric studies.

2025, International Journal of Radiation Applications and Instrumentation. Part D. Nuclear Tracks and Radiation Measurements

2025, Radiation Measurements

Alpha particle tracks were studied in 250 mm PC applying 50 HzeHV ECE method. Efficiency and diameter were determined versus field conditions, duration and energy. Efficiency, diameter and background density increase as HV and ECE duration increase. Alphas of ~300 keV to ~4.5 MeV were detected with efficiency up to ~70% at the Bragg peak. Some characteristics of 50 Hze2 kV and 2 kHze800 V methods are compared.

2025, Radiation Measurements

A new method is introduced in this paper for determination of 226Ra in food stuffs when it is in equilibrium with its decay products in prepared microprecipitates when alphas are detected by polycaronate detectors when electrochemically etched. The microprecipitates were prepared from food samples in particular from high level natural radiation areas of Ramsar, Iran by the collection of radium with lead as Pb/RaSO~. Then radium was coprecipiiated by addition of small amounts of a barium carrier leading to thin films or microprecipitates with negligible self absorption for alpha particles. The results compared to those obtained by the emanation method are in good agreements.

2025, Radiation Measurements

A new versatile electrochemical etching ECE chamber (VECE) system is introduced in which the effective electrochemically etched area can have variable sizes and/or shapes required using templet etching. The fiat rubber washers act as templets and holders of the etchant, and control the size and shape of the effective etched area of the detector which can be of various shapes and sizes desired. The system was operated in two operation modes A and B in which the both sides and one side of the detector were etched respectively. Detectors with etched areas having diameters from 1 to 18 cm have also been successfully etched by this system. Multi-chambers have been also designed using this principle for larger-scale multi-detector processing. The effects of etching area and time on the current through the detector have also been studied. Electrochemical etching (ECE); versatile ECE chamber (VECEC); templet etching; various shapes and sizes.

2025, Radiation Measurements

Photoneutron contaminations in and out of high energy X-ray beams of the medical linear accelerator SATURNE 20 (CGR) of the Radiotherapy Department of Omeed Hospital in Isfahan, Iran, have been determined using 250 ~rn polycarbonate (PC) dosimeters, m slrips or in sheets, processed by electrochemical etching (ECE) using specially designed ECE chambers to etch larger sheets. A two dimensional or topographical distribution of neutron contamination was also determined in a full size beam. The neutron dose equivalents (Hn) in the beam of 18 MV X-rays at 80 cm FSD were determined to be linear functions of Xray dose equivalents (Hx) up to 1400 cSv. The distribution of the Hn at different X-ray doses showed bell-shape profiles with maxima at the isocenter. The ratios of dose equivalents of neutrons to those of X-rays increased as the field size increased having values of 0.22%, 0.28%, 0.31% and 0.37% for field sizes of 10xl0, 20x20, 30x30o and 40x40 cm 2 respectively. Although such neutron dose equivalents can be corrected for patient treatment, it can cause radiation protection problems for workers where the design of the facility is not well planned.

2025, Radiation Measurements

Highlights of findings on radiological measurements, radiobiological and epidemiological studies in some main world high background natural radiation (HBNR) areas such as in Brazil, China, India and Iran are presented and discussed with special regard to remediation of radiation exposure of inhabitants in such areas. The current radiation protection philosophy and recommendations applied to workers and public from operation of radiation and nuclear applications are based on the linear non-threshold (LNT) model. The inhabitants of HBNR and radon prone areas receive relatively high radiation doses. Therefore, according to the LNT concept, the inhabitants in HBNR areas and in particular those in Ramsar are considered at risk and their exposure should be regulated. The HBNR areas in the world have different conditions in terms of dose and population. In particular, the inhabitants in HBNR areas of Ramsar receive very high internal and external exposures. This author believes that the public in such areas should be protected and proposes a plan to remedy high exposure of the inhabitants of the HBNR areas of Ramsar, while maintaining these areas as they stand to establish a national environmental radioactivity park which can be provisionally called "Ramsar Research Natural Radioactivity Park" (RRNRP). The major HBNR areas, the public exposure and the need to remedy exposures of inhabitants are reviewed and discussed.

2025, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

An "internal heating effect" was discovered at AEOI during electrochemical etching (ECE) of some polymeric dosimeters, by using our new multi-chamber ECE system. This phenomenon heats up the etchant significantly analogous to dielectric heating with a rate proportional to square of field strength (E~), frequency (f) and polymer loss index or loss factor ( ¢'x tan 6 ). Etchant temperature rise responses versus ECE time were determined for cellulose tri-acetate, cellulose acetate, allyl diglycol carbonate (CR-39), cellulose nitrate, cellulose acetate butyrate, polyester, polycarbonate, and polyethelene showing rates respectively in decreasing orde~ the same order as their loss indices. Effective foil diameter and etchant volume were shown to be imporant parameters in ECE. Recoil tracks at frequencies above about I0 to 20 kHz in CR-39 was found to form a "water bubble" in middle with water mictrostructure having a temporary behavior, analogous to water trees. This behavior was disussedtobe related to combined effects of electro-osmosis and dielectrophoresis mechanisms. Permanent dimensional changes in some polymers like CR-39, CA and CTA were related to electrostriction phenomenon. To sum up, the effects of four possible mechanisms including dielectric loss, electro-osmosis, dielectrophoresis, and electrostriction seems to clearly being observed in this study with a hope to put a step forward in better understanding of ECE mechanisms and to stimulate further research on different aspects of this technique to promote its applications.

2025, Contributions to Plasma Physics

Angular distribution of nitrogen ions from a 4 kJ plasma focus device (PFD), as obtained by two detection methods was studied. The results obtained with two methods including consisting of (i) polycarbonate (PC) detectors (1 mm thick with about 15 cm diameter large etchable area) using electrochemical etching (ECE) at 50 Hz and 48 kV cm -1 field strenth and (ii) an array of five Faraday cups (FC) are analyzed, compared and discussed in this paper. The results obtained by the two detectors are quite different. A new concept is proposed in this paper for the ring-shaped angular distribution of ions.

2025, Indian Journal of Physics

A projectile ( 84 Kr 36 ) having kinetic energy around 1 A GeV was used to expose NIKFI BR-2 emulsion target. A total of 700 inelastic events are used in the present studies on projectile fragments. The emission angle of the projectile fragments are strongly affected by charge of the other projectile fragments emitted at same time with different emission angle is observed. The angular distribution studies show symmetrical nature for lighter charge projectile fragments. The symmetrical nature decreased with the charge of projectile fragments. At ~4o of emission angle for double charge projectile fragments, the momentum transfer during interaction is similar for various target species of emulsion were observed. We also observed a small but significant amplitude peaks on both side of the big peak for almost all light charge projectile fragments having different delta angle values. It reflects that there are few percent of projectile fragments that are coming from the decay of heavy projectile fragments or any other process.

2025, Radiation Measurements

An underwater inspection system was developed which is able to monitor the state of reinforcement corrosion. The system is composed of a remotely operating vehicle (ROV) equipped with the sealed tube neutron generator (NG). All... more

2025, Radiation Measurements

A relatively rapid, economic and robust procedure is described for the alpha-radiometric analysis of natural waters. The analysis is performed by alpha-spectroscopy after pre-concentration and separation of uranium by cation-exchange (Chelex-100) and finally its electrodeposition on stainless steel discs. The method has been successfully applied to 100 ml samples of natural waters (e.g. ground-and seawaters) resulting in high-quality spectra for measurement times less than 34 h. In addition, a main advantage of the procedure (particularly for routine measurements) is that there is no consumption of organic solvents and multiple recycling/reuse of the resin is possible.

2025, Radiation Measurements

The study deals with the seasonal variation of the total alpha-radioactivity and the U-238/234 radioactivity concentration of ground waters in Cyprus. The radiometric measurements were performed after pre-concentration and selective ion-exchange procedures using liquid scintillation counting. According to the radiometric measurements the total alpha-radioactivity of the ground waters is basically associated with the uranium content in the water systems and the seasonal variation is mainly related to meteorological conditions (e.g. temperature and atmospheric precipitation). Assessments of the radiation exposure to population suggests that using these ground waters for human consumption would result in significantly increased radiation doses, whereas utilization of these waters for irrigation purposes wouldn't imply any excessive radiation exposure to population.

2025, Radiation Measurements

This paper presents an airborne radon monitoring (RM) system for aquatic radon determination after out-gassing of radon from the aqueous sample and compares this method with the standard ASTM method for radon analysis in aquatic samples, e.g. liquid scintillation counting (LSC) after extraction of radon by a scintillation cocktail. Calibration of the method shows good linearity, high efficiency (100%) and detection limits better than 0.1 Bq/l, indicating that the method is suitable for low-level radon determination in aquatic samples. Moreover, because RM is less time and material (e.g. LSC cocktail and vials) consuming it could be more attractive for routine measurements. Application of the two methods to natural aquatic samples results in almost similar radon concentrations (90% correlation) and shows that radon levels in Cypriot groundwaters vary from 0.1 to 15 Bq/l, depending strongly on the geological background.

2025, Radiation Measurements

Two different alpha-radiometric methods (e.g. alpha-spectroscopy and alpha-particle counting) have been applied to the determination of uranium in Cypriot groundwater samples after separation of the radionuclides by cation exchange using Chelex-100 and its electrodeposition on stainless steel planchettes. The data obtained were compared to show the advantages and disadvantages of the two radiometric methods, determine the alpha-radioactivity concentration and the radiation dose associated with the use of the studied groundwaters. Calibration of the methods was performed by means of uranium standard solutions and the corresponding data were used to evaluate linear range, detector efficiency, detection limits, value of the information obtained, and time of analysis of the methods. Comparison of the data obtained from calibration and natural sample measurements has shown that alpha-particle counting with a simple alpha-radiometer (equipped with a semiconductor detector) may offer only an activity value and not detailed information about the isotopic composition but it is the fastest method and the method of choice if only a screening method for the alpha-radioactivity measurement is required. Based on the alpha-radioactivity data, the corresponding radiation dose was estimated for situations where the groundwaters are used for drinking water purposes.

2025, Radiation Measurements

Changes in the radiation-induced transparency of scintillating and wavelength-shifting ÿbers were studied by means of on-line-induced absorption coe cient measurement during and after gamma irradiation. It was found that the main contribution to radiation damage was caused by reactions between luminescent molecules. The time dependence of the radiation-induced absorption coe cient was analyzed in the broad spectral range (420-735 nm) and compared with kinetic models of the processes of absorption center build-up and recovery. The latter has been recently published for these ÿbers and a lower dose rate in the range of 0.002-0:01 Gy s -1 . Good agreement was reached between the low-dose and the presented high-dose measurements (dose rate 4:2 Gy s -1 ). The parameters calculated in this kinetic model are applicable to prediction of the ÿber behavior in particle physics experiments.

2025, Radiation Measurements

The determination of 226 Ra, one of the most radiotoxic of the naturally occurring radioisotopes is very important for human health. The bladder and kidneys receive a significant dose of radiation when radioactive isotopes are excreted through the urine. Since most of the methods already developed to determine 226 Ra are time consuming, the aim of this work is to establish a time saving procedure, particularly suitable for routine analyses, to isolate 226 Ra in urine with a preliminary purification in order to measure it by Q-ICP-MS (Inductively Coupled Plasma Mass Spectroscopy). The detection limit of the method is 6.3 mBq L À1 . By using such methodology it is possible to process a large set of samples in 2e3 days.

2025

The influence of soil grain size on its radon emanation mechanism was investigated by developing a Monte-Carlo model. The proposed model supplements the previous formulations by accounting for the effect elicited by specific surface area of the sample. The specific surface area of a sample is governed by its grain size and it strongly influences the emanation rate which is a surface phenomenon. The emanation study was further extended to include the moisture effect. Experiments were carried out with two soil samples; Soil-2 and Soil-4 collected from different terrains, to analyze the role played by moisture in the emanation mechanism. The above model was augmented with provisions to include the moisture input. The model could reproduce the experimental results. There is an abrupt increase in the emanation factor when the moisture content changes from 0 to 2%. Thereafter, the increase is gradual and finally becomes steady when the moisture level reaches 10%. Soil-2 and Soil-4 showed sizeable difference in their radon emanation factor values. This could be explained based on the parent 226 Ra distribution pattern which stems from the mineralogical composition of the samples. Quartz was predominantly found in Soil-2, whereas Soil-4 shows peaks corresponding to minerals namely ilmenite, Rutile and Zircon confirming relatively higher concentration of heavy minerals than Soil-2. The emanation factor values of the individual minerals reported in the literature were used to decide upon the 226 Ra distribution depth and with this input the model to ascertain the experimental observations.

2025, Radiation Measurements

The risk due to cosmic radiation is a major issue in planning future missions to the Moon or Mars and would be critical if inadequately addressed. Functional risks must also be considered. The perception of light flashes reported by astronauts in space, and ascribed mostly to the action of ionizing radiation in the eye (retina), is an evidence for radiation functional interaction. No detailed model of the ion/retina interaction is yet available. Here we present the first model for a generation mechanism compatible with light flashes in space, and the results of in vitro tests supporting it. The model can be a common end point for the interactions between ionizing radiation and visual system in space. It would also support the assessment of functional radiation risks in space.

2025, Radiation Measurements

Fluorescent nuclear track detectors (FNTDs) based on Al 2 O 3 :C,Mg crystals

2025, Radiation Measurements

Fluorescent nuclear track detectors (FNTDs) based on Al 2 O 3 :C,Mg crystals

2025, Radiation Measurements

An extensive study of alpha particle track profile has been carried out in PADC plastic detectors. Track profile geometry and its parameters have been studied. Various values of alpha energies were used, and the etch rate ratio (V) was measured as a function of the residual range (RR) along the alpha particle track. A mathematical formula between V and RR was established. Also in this work, alpha particle ranges in plastic foils have been measured at various energies using two methods; namely the track profile technique (TPT) and the over etched track diameter method. A comparison between the measured ranges and calculated ones is presented, and a good agreement has been found. Track etch rate; etch pit profile; alpha particles.

2025

Copper nanowires of diameter 50 nm have been synthesized by electrochemical deposition in a nanoporous polycarbonate template. These membranes were created by ion irradiation of 30 µm thick polycarbonate foils at UNILAC accelerator of GSI, Germany. Subsequent chemical etching of these foils were carried out in PINSTECH using 6M NaOH solution at 50 o C. A thin Cu layer on one side of these membranes, deposited by thermal evaporation, acted as cathode. A Cu rod was used as anode and the deposition was carried out potentiostatically at room temperature in a two electrode electrochemical cell. Subsequent to fabrication, the wires were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and UV-Visible spectroscopy.

2025

TRIPOLI® and TRIPOLI-4® are registered trademarks of CEA.International audienceAlthough the Monte Carlo (MC) codes are natural users of the fast growing capacities in High PerformanceComputing (HPC), adapting production level codes such as TRIPOLI-4 to the hexascale is very challenging. Wepresent here the dual strategy we follow new thoughts and developments for the next versions of TRIPOLI-4, aswell as insights on a prototype of next generation Monte Carlo (NMC) designed from the beginning with hexascalein mind.The Random Generators of the code will also be presented as well as the strategy of verificationof the parallelism

2025

Arranged from oldest to youngest, the main granitic rock units exposed in Khour Abalea are metagabbros, cataclastic rocks, ophiolitic melange, granitic rocks, pegmatite and lamprophyre dykes. The presence of radioactivity associated with the heavy bearing minerals in construction materials-like granite-increased interest in the extraction process. As it turns out, granitic rocks play an important economic part in the examination of an area's surroundings. The radionuclide content is measured by using an NaI (Tl)-detector. In the mineralized pegmatites, U (326 to 2667 ppm), Th (562 to 4010 ppm), RaeU (495 to 1544 ppm) and K (1.38 to 9.12%) ranged considerably with an average of 1700 ppm, 2881.86 ppm, 1171.82 ppm and 5.04%, respectively. Relationships among radioelements clarify that radioactive mineralization in the studied pegmatites is magmatic and hydrothermal. A positive equilibrium condition confirms uranium addition to the studied rocks. This study determined 226 Ra, 232 Th and 40 K activity concentrations in pegmatites samples and assessed the radiological risks associated with these rocks. The activity concentrations of 226 Ra (13,176 ± 4394 Bq kg-1), 232 Th (11,883 ± 5644 Bq kg-1) and 40 K (1573 ± 607 Bq kg-1) in pegmatites samples (P) are greater than the global average. The high activity of the mineralized pegmatite is mainly attributed to the presence of uranium mineral (autunite), uranophane, kasolite and carnotite, thorium minerals (thorite, thorianite and uranothorite) as well as accessories minerals-such as zircon and monazite. To assess the dangerous effects of pegmatites in the studied area, various radiological hazard factors (external, internal hazard indices, radium equivalent activity and annual effective dose) are estimated. The investigated samples almost surpassed the recommended allowable thresholds for all of the environmental factors.

2025, Radiation Measurements

A suite of quartz samples of different provenances, irradiation, thermal and depositional histories were analysed using spectroscopic ionoluminescence (IL) to investigate variations in emission spectra as a function of cumulative radiation dosing. Protons were selected for implantation to mimic the effect of natural radiation over geological timescales. All samples exhibited depletion in the UV-violet emission (3.2-3.4 eV) with increasing cumulative dose, whilst the red emission (1.8-1.9 eV) increased. A power-law relationship exists between the two emissions. It is inferred that the luminescence emission of quartz is indicative of its radiation history, and spectral analyses could be used to determine the utility of different quartz samples for optically stimulated luminescence dating (OSL) where the detection range is limited to 3.4-4.6 eV.

2025, Radiation Measurements

-TL emission spectra dependent on mineral phases, framework disorder and interfaces -Single-phase feldspars show little anomalous fading -Framework disorder increases intensity of blue TL emission and IRSL fading rate

2025, Radiation Measurements

We constrain parameters that determine thermal stability of the infrared stimulated luminescence (IRSL) signal in a suite of 13 compositionally different feldspar samples by optical probing. We focus specifically on the excited and ground state of the principal trap and the width of the sub-conduction band-tail states. Excitation spectra measured at room temperature result in approximate trap depth of about 2.04 eV and the excited state energy at 1.44 ± 0.02 eV, irrespective of feldspar composition for the sample's measured here. Fitting the non-resonant rising continuum of the excitation spectra suggests that the width of the band-tail states accessible from the ground state of the trap (ΔE) ranges from 0.21 to ACCEPTED MANUSCRIPT 2 0.47 eV at room temperature between the different samples. Photoluminescence measurements are used to constrain the full sub-conduction band-tail width (Urbach width, E u ) using the excitation-energy-dependent emission (EDE), resulting in values ranging from 0.26 to 0.81 eV. While the depth of the principal trap and its main excited state seem to be

2025, Radiation Measurements

The kinetic analysis of thermoluminescence of beta-irradiated SrAl 2 O 4 :Eu 2+ ,Dy 3+ is reported. The glow-curve is dominated by an apparently-single peak. It has been demonstrated using a number of tests including partial dynamic-heating, isothermal heating, phosphorescence and, the effect of fading, that the peak and the glow-curve consists of a set of closely-spaced peaks. In view of the peak being complex, its first few components were abstracted and analysed and for comparison, the peak was also analysed assuming it is genuinely single. In the latter, the order of kinetics is calculated to be intermediate between first and second-order and not first-order as predicted by qualitative tests such as the or procedures. A model based on density of energy states has been used to account for and reconcile the qualitative and quantitative results. The activation energy is found as ~1 eV, consistent with the value expected of Dy 2+ , the presumed electron trapping state of the Dy 3+ electron trap. The thermoluminescence is subject to thermal quenching with an activation energy of 0.520 ± 0.002 eV. The luminescence is ascribed to 5d→4f 7 Eu 2+ transitions whereas the thermal quenching is presumed to occur from an alternative level of the degenerate 5d energy level of the Eu 2+ cation.

2025, Radiation Measurements

High levels of natural radiation areas occur in some parts of coastal tracts of India. The newly discovered Erasama beach placer deposit, part of the eastern coast of Orissa State, India is a high natural background radiation area, due to the presence of radiogenic heavy minerals. The average activity concentrations of radioactive elements such as 232 Th, 238 U and 40 K, measured by gamma-ray spectrometry using an HPGe detector, and found to be 2825±50, 350±20 and 180±25 Bq kg -1 , respectively, for the bulk sand samples. The absorbed gamma dose rates in air due to the naturally occurring radionuclides varied from 650 to 3150 nGy h -1 with a mean value of 1925 ± 718 nGy h -1 . The annual external e ective dose rates for the region varyed from 0.78 to 3:86 mSv yr -1 with a mean value of 2:36 ± 0:88 mSv yr -1 . The external gamma dose rate level of Erasama coastal region is similar to the other monazite sand bearing high background radiation areas of southern and southwestern coastal regions of India. The major contributors to the enhanced level of radiation are monazites and to a lesser extent in zircons.

2025, Radiation Measurements

In order to provide reliable reference values, many metrological activities were carried out. They consisted in calibration of a subset of the radon active monitors at the Italian National Metrological Institute

2025, Radiation Measurements

With an increasing interest in using protons and light ions for radiation therapy there is a need for possibilities to simultaneously determine both absorbed dose (D) and linear energy transfer, LET, (LΔ). Potassium dithionate (K2S2O6) tablets were irradiated in a conventional 6 MV linear accelerator photon beam and a N 7+ beam (E = 33.5 MeV/u) respectively. The EPR spectrum of irradiated potassium dithionate is a narrow doublet consisting of two signals, R1 and R2, with different microwave power saturation properties. On the basis of identification in related substances by EPR and ENDOR, these two signals are assigned to two nonequivalent SO3 --radicals. Our experiments showed that the ratios of these two lines (R1/R2) were clearly connected to beam LET. Irrespective of the mechanistic details this investigation suggests a new method for measurement of absorbed dose and beam LET by using potassium dithionate EPR dosimetry.

2025, Radiation Measurements

The response of PN3 and CR-39 personal dosemeters with different configurations, developed by the IReS (Strasbourg), the IPNO (Orsay) and the UAB (Barcelona) groups, is investigated in this study. Both dosemeters were mounted on a waterfilled phantom and were simultaneously exposed under different incidence angles (0 • , 30 • and 60 • ) to the following: (i) three ISO neutron sources ( 241 Am-Be, bare 252 Cf and moderated 252 Cf with Cd shielding), and (ii) two realistic neutron sources (SIGMA and moderated 252 Cf) at the IRSN (Cadarache) facilities. After irradiation, the plastic detectors were etched and evaluated according to local routine procedures and corrections for the effect of source-to-detector distance were taken into account. A comparison of the average background, the minimum detectable dose equivalent and the field calibration factor is performed as well.

2025, Indian Journal of Pure and Applied Physics

Multi-crystalline LiF plates have been grown by edge defined film fed growth (EFG) technique. The apparatus used for growing these plates both under vacuum and protective atmosphere has been locally designed and fabricated. The growth procedure is described. LiF plates measuring 10-15 mm wide, 1-1.5 mm thick and 10-15 cm long have been grown in an atmosphere of high purity argon. Physical and optical properties of these plates are presented along with pictures of the crystal plates. 1 Introduction Crystals of LiF have extensive uses in many applications such as the manufacture of lenses, analysis crystal in X-ray monochromator plates, instrument components such as UV transmission windows and to record gamma and neutron exposure in thermoluminescence (TL) dosimetry 1,2,3 . It also possess the highest UV transmission of any material being able to transmit significantly into the vacuum ultraviolet region at the hydrogen Layman alpha (L-α) line (121 nm) and is used for windows in space ...