Zohra Lounis-Mokrani

Nuclear Research Center of Algiers · Ionizing Radiation Dosimetry Department

Purpose: Radioiodine-131 (RAI or iodine-131) is one of the most frequently used radionuclides for diagnosis and therapy of thyroid diseases (90% of all therapies in nuclear medicine). In order to optimize the patient protection, it is important to evaluate the long-term biological effects of RAI therapy on non-target organs. Materials and methods...

The monitoring of the alpha irradiation effect on the microstructural deformation of CR39 via the variation of free volumes has been studied. CR39 samples have been irradiated with alpha particles at fluencies Ф of 2.6 · 108, 5.27 · 108, 7.91 · 108, 1.3 ·109, 1.84 · 109, and 3.6 · 109 α/cm2. The samples have been investigated with positron annihila...

The radiological monitoring of the eye in the workplace depends on the type of dosemeter used and its performance. The dosimetric performances of Nuclear Research Center of Algiers (CRNA) developed eye lens dosemeter (Larabi-Harfouche et al. Characterization and qualification of a CRNA eye dosimeter. Perspect Sci. 12, 100402 (2019)) are investigate...

Since 2004, the k0-standardization method has been applied and evaluated in three experimental channels at Es-Salam research reactor of the Algerian Centre de Recherche Nucléaire de Birine (CRNB). The NAA laboratory at CRNB is well involved in the implementation of the Prompt Gamma Neutron Activation Analysis to extend the field of analyses to some...

Since 2004, the k0-standardization method has been applied and evaluated in three experimental channels at Es-Salam research reactor of the Algerian Centre de Recherche Nucléaire de Birine (CRNB). The NAA laboratory at CRNB is well involved in the implementation of the Prompt Gamma Neutron Activation Analysis to extend the field of analyses to some...

Understanding the chemistry of radiation-induced polymerization in polymer gel dosimeters is of great importance in the evaluating of the capability, stability and efficacy of the polymer gel to measuring accurately the three-dimensional dose response. The aim of this work is to characterize the chemical and structural modifications induced by gamm...

In order to establish the national radon level according to the ICRP recommendations, radon levels should be estimated in different living environments (dwellings, workplaces, hospitals, etc.). A particular attention should be given to the correctness of the radon concentration measurement devices in order to maintain their traceability to primary...

The aim of this work is to study the calibration methodology of a new eye dosimeter, developed by Dosimetry Laboratory of the Nuclear Research Center of Algiers, using TLD-700 thermoluminescent detectors (LiF: Mg, Ti). Qualification and type test of this dosimeter have been performed in terms of operational quantity Hp(3) at Secondary Standard Dosi...

Iodine-131 ( ¹³¹ I) is one of the most frequently used radionuclides for diagnosis and therapy of thyroid diseases. It is administered orally in the treatment of cancer to eliminate the residual postoperative microscopic tumor foci, and the residual normal thyroid tissue for early detection of recurrence [ bibrR11 ]. The comparative behavior of ¹³¹...

Procedures using iodine-131 ( ¹³¹ I) represent about 90% of all therapies in nuclear medicine [ bibrR11 , bibrR22 ]. It is important to evaluate the long-term biological effects of ¹³¹ I treatment on non-target organs in order to improve the patient radioprotection. The aim of this work is to use an experimental animal model to contribute to the un...

For the radon map elaboration, radon measurements are generally performed in different seasons. Correction factors must be applied in order to represent comparable concentrations. The effects of environmental parameters have been investigated for the determination of these seasonal correction factors. Radon concentration measurements have been perf...

For the national radon map elaboration, radon measurements are generally performed in different seasons corresponding to different radon concentrations. Correction factors must be applied in order to represent the maximal concentrations. In this study, the effects of environmental parameters have been investigated for the determination of these sea...

Procedures using iodine-131 represent more than 90% of all therapies in nuclear medicine in Algeria. It is important to evaluate the long-term biological effects of iodine treatment on non-target organs to improve patient radiation protection. This experimental radiotoxicology study aims to determine the biokinetic models of iodine contamination. F...

Dans cette étude, nous avons évalué le risque potentiel d'exposition externe sur site en mesurant le débit de dose autour et à l'intérieur des conduites et des installations pétrolières où se déposent les matières radioactives naturelles (NORM).

Dans ce travail nous présentons les résultats de l’effet des RX 18 MV sur le gel polymère nommée gel MAGIC afin de pouvoir l’appliquée en dosimétrie lors de la simulation en 3D d’un traitement de radiothérapie. Le développement et la caractérisation du gel MAGIC ont fait l’objet de deux communications CNPA 2012 [1] et jemp 2013 [2] décrivant les pe...

As part of the intercomparison on the measurement of personal dose equivalent Hp(10), jointly organised by the International Atomic Energy Agency and the Algerian Secondary Standard Dosimetry Laboratory, for the African region, up to 12 dosemeters were added to the packages of the 28 participants to evaluate the background and transport dose (BGTD)...

Dans cette communication nous présentons les résultats de l’effet des RX 18 MV sur le gel polymère nommée gel MAGIC afin de pouvoir l’appliquée en dosimétrie lors de la simulation en 3D d'un traitement de radiothérapie. Le développement et la caractérisation du gel MAGIC ont fait l’objet de deux communications CNPA 2012 [1] et jemp 2013 [2] décriva...

An intercomparison exercise on the measurement of personal dose equivalent Hp(10) was jointly organised by the International Atomic Energy Agency and the Nuclear Research Centre of Algiers through its Secondary Standard Dosimetry Laboratory in the African region. This intercomparison exercise was aimed at verifying the performance of the individual...

An intercomparison exercise on the measurement of personal dose equivalent H p (10) was jointly organised by the International Atomic Energy Agency and the Nuclear Research Centre of Algiers through its Secondary Standard Dosimetry Laboratory in the African region. This intercomparison exercise was aimed at verifying the performance of the individu...

Radon activity concentrations have been measured in 34 workplaces throughout Algiers nuclear research centre, in Algeria, during some periods between March 2007 and June 2013 using Electret ion chambers, nuclear tracks detectors and an AlphaGuard system. The indoor radon levels range from 2 to 628 Bq m−3 with an average indoor concentration equals...

A fully detailed Monte Carlo geometrical model of an 18 MV Varian Clinac 2100C medical linear accelerator, lodged at Blida Anti-Cancer Centre in Algeria, was developed during this study to estimate the photoneutrons spectra and doses at the patient table in a radiotherapy treatment room, for radiation protection purposes. Subsequently, thanks to th...

A fully detailed Monte Carlo geometrical model of an 18 MV Varian Clinac 2100C was developed using MCNP5 code. Photoneutron spectra and ambient dose equivalent were calculated at the patient table. Sensitivity analysis was performed to estimate the variation on the production of the photoneutron doses at the selected locations. A comprehensive vali...

Dans cette communication, nous présentons les résultats de la caractérisation d’un nouvel outil de dosimétrie expérimentale 3D : le dosimètre gel polymère. Ce dosimètre, basé sur l’utilisation du gel MAGIC est formé de nanoparticules de monomère méthacrylique qui se polymérise sous l’effet de l’irradiation. La répartition spatiale le cette polyméri...

Radon (222Rn) concentrations were determined in some Algerian water sources. Sampling points were chosen randomly around El-Hodna Chott, in the north east of Algeria. For these measurements, an AlphaGUARD equipped with an appropriate unit (Aqua Kit) was used. All results are illustrated according to the location of measurement site, depth of water...

The behaviour of trap centres and luminescence centres has been investigated for fired and unfired natural quartz from bricks and sediments irradiated at 100Gy and annealed at different temperatures in the range 350–700°C. The annealing treatment affects thermoluminescence (TL) glow curve as various changes were observed. The higher sensitization o...

The Algerian legislation in 2005 has adopted the dose limits recommended by International Commission on Radiological Protection (ICRP 60, 1990) : 20 mSv per year averaged over a period of 5 years for workers and 1 mSv for public. It has also been recommended (ICRP 65, 1993) that of the natural exposure sources only radon in workplaces and work with...

In this study, the effect of gamma pre-treatment on etching rates has been investigated on CR-39 detectors manufactured by Pershore Mouldings (PM) as standard grade and (PM355) as dosimetry grade. The detectors have been exposed to 60Co gamma rays at absorbed dose ranging from 0 to . The chemical etching was carried out in four PEW solutions (potas...

The radial size of the damaged region induced by the proton beams in the CR-39 has been determined by small angle neutron scattering (SANS).The radii of the track core have been estimated by SANS technique using Guinier-plots and have been found to be about 0.7±0.2, 0.9±0.4 and 1.5±0.4nm at the fluences of 1011, 1012 and 5×1012cm-2, respectively.Th...

In the present work, measurements have been performed using an available multisphere neutron spectrometer based on a calibrated 6LiI scintillation detector () exposed to an 241Am–Be neutron source. Sensitive analysis has been performed to assess influence of angle and source–detector distances dependence on the detector responses. Our experimental...

The thermoluminescence detectors (TLD) have been widely used for environmental radiation monitoring around nuclear facilities. In this study, a new environmental dosimeter based on Al2O3:C detectors placed in black Perspex holder with appropriate filtrations (0.2mm Aluminium, 0.2mm Copper and 0.4mm Lead) has been proposed. The energy response benea...

Dating and retrospective dosimetry are the main applications related to the properties of thermoluminescence of fired quartz. The performance of these techniques can be improved by understanding and characterisation of the traps and luminescence centers responsible for the thermoluminescence emission. In this study, a fired quartz powder sample, ex...

Chemical and optical modifications induced by protons slowed down into a polyallyl diglycol carbonate (CR-39) stack, which was composed of 16 detectors of different thicknesses, are studied. Irradiation was performed perpendicular to the stack surface, in a vacuum chamber, with proton fluences ranging from 1011 to 1014 particles/cm2. These transfor...

Etchable track formation in poly-allyl-diglycol carbonate (commercially known as CR-39) track detectors is a process directly related to density of damage produced along the charged particle path; it requires knowledge of the variation of bulk etch rate Vb and track etch rate Vt as a function of the initial particle energy and etching time. In this...

This paper reports the theoretical studies undertaken to determine the optimum dimensions of the diffusion chamber and the membrane thickness which is sufficient to prevent the thoron gas diffusion and permit the rapid establishment of equilibrium between radon concentration outside and inside the chamber volume.

A fast neutron personal dosemeter based on the two-step electrochemcially etched CR-39 detectors has been developed by the “Centre de Radioprotection et de Sûreté” (CRS), in as simple a form as possible to be used in routine monitoring of neutron irradiated workers in Algeria.This paper presents the dosimetric characteristics of the developed dosem...

A fast neutron personal dosemeter based on CR-39 nuclear track detectors has been developed in as simple a form as possible to be used in routine monitoring. It has been investigated during the last joint irradiation exposures to neutrons organised by EURADOS-CENDOS committee on the application of track detectors in neutron dosimetry.The energy res...

The use of polycarbonate bottles as track detectors makes it possible to overcome some of the shortcomings of the electrochemically etched dosemeters such as the complexity of the etching apparatus, the strong angular dependence, and the difficulty of measuring the neutron incident angle. Because of its shape, the bottle provides a dosemeter with i...

The Dosimetry Laboratory of the Radiation Protection and Safety Centre in Algiers has developed a fast neutron personal dosemeter using a PADC detector. This dosemeter has been type tested in terms of the ICRU calibration quantity, directional dose equivalent at 10 mm, H'(10). This paper gives the results of type test measurements. In addition, som...

The Dosimetry Laboratory of the Radiation Protection and Safety Centre in Algiers has developed a fast neutron personal dosemeter using a PADC detector. This dosemeter has been type tested in terms of the ICRU calibration quantity, directional dose equivalent at 10 mm, H'(10). This paper gives the results of type test measurements. In addition, som...

The laboratoire de dosimetrie of the Centre de Radioprotection et de Sureté (CRS), Algiers, has been developing a fast neutron personal dosemeter using CR-39 detectors. Among track etch detectors used today, CR-39 remains the best available personal dosemeter for neutrons. Unfortunately, the drawbacks in using CR-39 as a neutron detector still exis...