A5063351894- Nuclear Physics and Applications
- Radioactivity and Radon Measurements
- Radiation Detection and Scintillator Technologies
- Radioactive contamination and transfer
- Advanced Semiconductor Detectors and Materials
- Nuclear and radioactivity studies
- Ion-surface interactions and analysis
- Radiation Dose and Imaging
- Particle Detector Development and Performance
- Radiation Therapy and Dosimetry
- Atomic and Molecular Physics
- X-ray Spectroscopy and Fluorescence Analysis
- Chalcogenide Semiconductor Thin Films
- Graphite, nuclear technology, radiation studies
- Medical Imaging Techniques and Applications
- Radiation Effects in Electronics
- Advanced X-ray and CT Imaging
- Electron and X-Ray Spectroscopy Techniques
- Radioactive Decay and Measurement Techniques
- Risk Perception and Management
- Mass Spectrometry Techniques and Applications
- Diamond and Carbon-based Materials Research
- Nuclear Issues and Defense
- Planetary Science and Exploration
- Radiation Shielding Materials Analysis
Greek Atomic Energy Commission
2016-2025
National and Kapodistrian University of Athens
2022-2024
University of Belgrade
2019
International Atomic Energy Agency
2018
Aristotle University of Thessaloniki
2008
National Centre of Scientific Research "Demokritos"
1993-1999
Goethe University Frankfurt
1999
Institute of Nuclear and Particle Physics
1993-1996
Abstract Coded Aperture γ -cameras have been extensively used in applications ranging from astrophysics to nuclear medicine for imaging radioactive source distributions. These devices allow the identification of direction -emitters by analyzing shadow patterns projected onto pixelated detectors. In this work, we propose a novel approach based on Convolutional Neural Networks (CNNs) accurately localizing sources 3D using one coded aperture gamma camera. The CNN is trained simulated...
Abstract Naturally Occurring Radioactive Material (NORM) may pose radiological risks across various industrial processes. Characterizing NORM is challenging due to radionuclide diversity, complex material matrices, and the multiple analytical techniques required. This study documents an Intercomparison Exercise (ICE) on radioanalytical characterization of NORM, organized by International Atomic Energy Agency EEAE evaluate participants’ abilities implement appropriate promote harmonization,...
The COCAE project develops an instrument for localization and identification of radioactive sources. For the task it will exploit Compton scattered photons within its detecting layers. It is based on pixilated Cd(Zn)Te matrices in a stacked configuration. Progress has been achieved all components necessary this technology. CdZnTe crystals have grown up to 75 mm diameter. A wafer level pixelization process tested results be presented. Angular resolution directional order 6 <sup...
Since the double disaster of 9.0 magnitude earthquake and tsunami that affected hundreds thousands people seriously damaged Fukushima Daichi power plant in Japan on 11 March 2011, traces radioactive emissions from have spread across entire northern hemisphere. The isotope iodine 131I was generated by nuclear accident arrived Greece 24 2011. Radioactive is present air either as gas or bound to particles (aerosols). maximum concentrations were measured between 3 5 April In aerosols values...
The complexation of 238U and 234U in tap water seawater after the use a selective membrane was examined. At first step, many ligands were used for original membranes preparation their yields uranium analysis evaluated by X-ray fluorescence, order to select ligand with highest selectivity samples. second step new prepared α-spectrometry. Various factors tested more effective binding such as membrane's active surface, sample volume, equilibration time, stirring during process. After...
Indoor radon concentrations were measured in 77 schools of the prefecture Xanthi northern Greece. The arithmetic mean concentration is 231 Bq m−3 with a range between 45 and 958 m−3. Thirty five have above 200 nine 400 From continuous gas measurements school relative higher (958 m−3) was deduced 'true' concentration, defined as during hours presence teachers scholars. for time period about 2 weeks 104 same seven times (700 m−3). Greek International regulations workplaces refer to only annual...
Coded aperture imaging transcends planar with conventional collimators in efficiency and Field of View (FOV). We present experimental results for the detection 141 keV 122 γ-photons emitted by uniformly extended 99mTc 57Co hot-spots along simulations normally hot-spots. These prove that method can be used intra-operative radio-traced sentinel nodes thyroid remnants. The study is performed using a setup two gamma cameras, each consisting coded-aperture (or mask) Modified Uniformly Redundant...
Moon is an auspicious environment for the study of Galactic cosmic rays (GCR) and Solar particle events (SEP) due to absence magnetic field atmosphere. The same characteristics raise radiation risk human presence in orbit around it or at lunar surface. secondary (albedo) resulting from interaction primary with soil adds extra factor, because neutrons are produced, but also can be exploited composition. In this paper, design a comprehensive monitor package tailored presented. detector, named...
We report on measurements of the number electrons per incoming projectile emitted from entrance and exit surfaces thin carbon foils as function atomic Z (1\ensuremath{\leqslant}Z\ensuremath{\leqslant}32), incident charge states, velocities below, near, above stopping power maximum. The screening by reduces backward electron emission. corresponding reduction parameters have been determined electrons. For all ions but protons we note a general trend that forward to yield ratio...
Medical examinations performed on four monks of a monastery in the northern Greece revealed heavy metal contamination. Hair analysis, by toxicological laboratory abroad, indicated, among other, presence uranium. The uranium concentrations determined "Elemental Analysis' indicated level that was about five times maximum value reference range, which has been adopted measuring laboratory. After these diagnostic findings, request 10 monks, determination hair and urine samples means alpha...
The charge transport mechanism and spectrometric properties of the X-ray γ-ray detectors, fabricated by deposition molybdenum oxide thin films onto semiinsulating p-CdTe crystals were studied. current processes in Mo-MoO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> /p-CdTe/MoO -Mo structure are well described scope carrier's generation space-charge region space-charge-limited models. lifetime carriers, energy hole traps, density...
Electrical characteristics of Mo-MoO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> /p-CdTe/ MoO -Mo, Ti-TiO /p-CdTe/MoO and Ti-TiN/p-CdTe/ -Mo structures, manufactured by magnetron sputtering the thin films on CdTe semi-insulating crystals, produced Acrorad Co. Ltd. were studied. The optimization conditions substrate pretreatment contacts deposition allowed to reduce dark current detectors compared earlier analogs and, consequently,...
A radiation protection system to assess the internal contamination of workers during decontamination activities in an abounded fertilizer industry region Attika, Greece, has been implemented. This concerns, among other radionuclides, 226Ra. Because low 226Ra urine, alpha spectrometry was used as determination method after radiochemical separation. Radium co precipitated with lead sulphate and purified using anion cation exchange techniques. The source for spectrometric measurement prepared...
Journal Article Assessment of the occupational exposure at a fertiliser industry in northern part Greece Get access C. Potiriadis, Potiriadis * Greek Atomic Energy Commission, PO Box 60092, Agia Paraskevi, 15310 Attiki, *Corresponding author: cpot@gaec.gr Search for other works by this author on: Oxford Academic PubMed Google Scholar V. Koukouliou, Koukouliou S. Seferlis, Seferlis K. Kehagia Radiation Protection Dosimetry, Volume 144, Issue 1-4, March 2011, Pages 668–671,...
Recommendations and requirements for the management of foodstuffs including drinking water feedstuffs (but not other commodities) contaminated after a nuclear accident or radiological event have been developed by international bodies such as Codex Alimentarius Commission European Union well individual countries.However, experience from severe accidents (Chernobyl, Fukushima) less serious events, shows that implementation systems (based on criteria expressed in activity concentration) seems...
The development of instruments utilizing coded apertures has become more feasible with the progress Cd(Zn)Te hybrid detector technology. collective performance systems comprised by such devices can be evaluated in all fields where traditionally aperture imaging been applied. Along this direction, we present evaluation a system, which consists two identical gamma cameras. Each an active area 4.4× 4.4 cm2 16384 pixels. cameras are used for estimation spatial coordinates radioactive source...
Several small gamma cameras for radioguided surgery using CdTe or CdZnTe have parallel pinhole collimators. Coded aperture imaging is a well-known method ray source directional identification, applied in astrophysics mainly. The increase efficiency due to the substitution of collimators by coded masks renders attractive probes used surgery. We constructed and operationally verified setup consisting two with Modified Uniform Redundant Array (MURA) rank 7 19 video camera. 3-D position...
This paper reports on the possible applications of molybdenum oxide (Mo/MoO x ) contacts in combination with semi‐insulating CdTe crystals. The electrical to p‐type Cl‐doped crystals were formed by deposition and pure thin films DC reactive magnetron sputtering. Electrical properties prepared Mo‐MoO /р‐CdTe/MoO ‐Mo surface‐barrier structures investigated at different temperatures. It is shown that rapid growth reverse current increasing bias voltage higher than 10 V caused space‐charge...
Among the patterning technologies proposed and applied for realization of high-aspect-ratio structures in micro- nanoscale, proton beam writing (PBW) is considered to be a valuable tool maskless such owing unique ability protons maintain straight path over long distances. In this work, PBW capabilities are demonstrated through simulation results fine resist films. These prove capability produce very tall with almost vertical sidewalls, aspect ratio limited practically only by performance...
Abstract This paper describes the peak‐to‐background ratio improvement that can be achieved in PIXE and XRF applications by use of thin crystal detectors. becomes apparent presence an intense γ‐ray source, which produced either during proton irradiation a sample (PIXE) or deexcitation radionuclide radioisotope‐induced analysis (RIXRF). In order to study theoretically energy response silicon x‐ray region with respect its thickness incident γ‐radiation, Monte Carlo simulation was performed....