Nowadays, the accuracy of experimental results relies more and more on detailed simulations. In the STEREO experiment, the interaction of neutrinos in the liquid scintillator is signed by a n-capture on a Gd atom. The FIFRELIN predictions of the Gd γ-cascades were shown to significantly improve the Data/MC agreement. In the CRAB method, lately proposed to calibrate cryogenic particle detectors at low energy (100 eV), the FIFRELIN cascades of the W and Ge isotopes played a central role in the feasibility study of the method. The FIFRELIN code employs a Monte Carlo Hauser-Feshbach framework based on Bečvár’s algorithm. A sample of nuclear level schemes is generated for a specific isotope of interest, taking into account the uncertainties from nuclear structure. In this work, new improvements on the FIRELIN de-excitation process are reported. Angular correlations of γ-rays in the de-excitation process have been implemented in order to provide a more accurate description of the γ-ray cascades. The anisotropy of the γ-rays with respect to the axis of a previously emitted γ-ray is modeled using the angular correlation formalism, which requires input of the spins and multipolarities of the states involved in the FIFRELIN cascade. Furthermore, the simulation of primary γ-rays emitted from (n,γ) reactions has been updated using the EGAF database.
{"title":"Recent developments in the modeling of (n,γ) reactions with FIFRELIN","authors":"A. Chalil, T. Materna, O. Litaize, A. Chebboubi","doi":"10.12681/hnps.3606","DOIUrl":"https://doi.org/10.12681/hnps.3606","url":null,"abstract":"Nowadays, the accuracy of experimental results relies more and more on detailed simulations. In the STEREO experiment, the interaction of neutrinos in the liquid scintillator is signed by a n-capture on a Gd atom. The FIFRELIN predictions of the Gd γ-cascades were shown to significantly improve the Data/MC agreement. In the CRAB method, lately proposed to calibrate cryogenic particle detectors at low energy (100 eV), the FIFRELIN cascades of the W and Ge isotopes played a central role in the feasibility study of the method. The FIFRELIN code employs a Monte Carlo Hauser-Feshbach framework based on Bečvár’s algorithm. A sample of nuclear level schemes is generated for a specific isotope of interest, taking into account the uncertainties from nuclear structure. In this work, new improvements on the FIRELIN de-excitation process are reported. Angular correlations of γ-rays in the de-excitation process have been implemented in order to provide a more accurate description of the γ-ray cascades. The anisotropy of the γ-rays with respect to the axis of a previously emitted γ-ray is modeled using the angular correlation formalism, which requires input of the spins and multipolarities of the states involved in the FIFRELIN cascade. Furthermore, the simulation of primary γ-rays emitted from (n,γ) reactions has been updated using the EGAF database.","PeriodicalId":262803,"journal":{"name":"HNPS Advances in Nuclear Physics","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114661484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Mavrikis, A. Markopoulos, Elena Dalla, A. Ioannidou, A. Savidou
Adequate radiological characterization is important for optimization of metallic waste management. For decommissioning planning, the objective is to obtain a radiological understanding of the involved installation. The characterization at this stage could be carried out by means of: 1) neutron activation calculations based on reactor design and neutron flux; 2) dose rate measurements; 3) in-situ gamma spectrometry; 4) sampling for determination of the scaling factors in activated and contaminated components. During dismantling, in-situ characterization is carried out to classify and package the generated waste. Then, the packages are monitored for assessment of activity and determination of the management route. The selection of cutting and decontamination techniques should be based on accurate determination of the radionuclides inside the material and/ or on the surface contamination. . It is important to decide in which cases the decontamination will be efficient as well as to select the appropriate decontamination techniques based on whether the waste is slightly activated or contaminated or both. Α Semi-empirical technique for optimization of determination of contamination and activation of components and metallic waste is under development based on combination of gamma spectrometry measurements and MCNPX Monte Carlo simulations. Firstly, the technique aims at reduction of the uncertainties related to the density and activity distribution. The specific activities inside and on the surface of the materials could be determined by using the measurement results of the proposed non-destructive technique in combination with the use of the scaling factors for activation and/ or contamination.
{"title":"A Technique for Metallic Waste Characterization and Segregation in Management Routes","authors":"D. Mavrikis, A. Markopoulos, Elena Dalla, A. Ioannidou, A. Savidou","doi":"10.12681/hnps.3564","DOIUrl":"https://doi.org/10.12681/hnps.3564","url":null,"abstract":"Adequate radiological characterization is important for optimization of metallic waste management. For decommissioning planning, the objective is to obtain a radiological understanding of the involved installation. The characterization at this stage could be carried out by means of: 1) neutron activation calculations based on reactor design and neutron flux; 2) dose rate measurements; 3) in-situ gamma spectrometry; 4) sampling for determination of the scaling factors in activated and contaminated components. During dismantling, in-situ characterization is carried out to classify and package the generated waste. Then, the packages are monitored for assessment of activity and determination of the management route. The selection of cutting and decontamination techniques should be based on accurate determination of the radionuclides inside the material and/ or on the surface contamination. . It is important to decide in which cases the decontamination will be efficient as well as to select the appropriate decontamination techniques based on whether the waste is slightly activated or contaminated or both. Α Semi-empirical technique for optimization of determination of contamination and activation of components and metallic waste is under development based on combination of gamma spectrometry measurements and MCNPX Monte Carlo simulations. Firstly, the technique aims at reduction of the uncertainties related to the density and activity distribution. The specific activities inside and on the surface of the materials could be determined by using the measurement results of the proposed non-destructive technique in combination with the use of the scaling factors for activation and/ or contamination.","PeriodicalId":262803,"journal":{"name":"HNPS Advances in Nuclear Physics","volume":"16 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113942414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Davis, M. Diakaki, M. Kokkoris, V. Michalopoulou-Petropoulou, R. Vlastou
In the present work, the simulated detector was a MicroMegas gaseous one, regularly being used for neutron-induced fission studies at NCSR ‘Demokritos’. The initial code tests involved the linear response of the detector with respect to the energy deposition of 5 MeV α-particles. This study was carried out in two distinct steps: First, by collecting simulated data for the deposited charge in the anode electrode for different particle trajectories, as well as, for the same trajectory, but for different gas pressures, ranging between 0.8 and 1.2 atm and then by comparing them with the corresponding results obtained using SRIM2008 regarding the α-particle energy losses inside the detector, with the same set of parameters. Finally, a simulated spectrum of 5 MeV α-particles, having trajectories randomly distributed within the whole detector volume, was obtained using Garfield++ and was compared to an experimental one. The similarities and discrepancies observed are discussed and analyzed.
{"title":"Simulation of a MicroMegas detector for low-energy α-particle tracking using Garfield++","authors":"M. Davis, M. Diakaki, M. Kokkoris, V. Michalopoulou-Petropoulou, R. Vlastou","doi":"10.12681/hnps.3715","DOIUrl":"https://doi.org/10.12681/hnps.3715","url":null,"abstract":"In the present work, the simulated detector was a MicroMegas gaseous one, regularly being used for neutron-induced fission studies at NCSR ‘Demokritos’. The initial code tests involved the linear response of the detector with respect to the energy deposition of 5 MeV α-particles. This study was carried out in two distinct steps: First, by collecting simulated data for the deposited charge in the anode electrode for different particle trajectories, as well as, for the same trajectory, but for different gas pressures, ranging between 0.8 and 1.2 atm and then by comparing them with the corresponding results obtained using SRIM2008 regarding the α-particle energy losses inside the detector, with the same set of parameters. Finally, a simulated spectrum of 5 MeV α-particles, having trajectories randomly distributed within the whole detector volume, was obtained using Garfield++ and was compared to an experimental one. The similarities and discrepancies observed are discussed and analyzed.","PeriodicalId":262803,"journal":{"name":"HNPS Advances in Nuclear Physics","volume":"259 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130920706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cesium-137 (137Cs) is the most important indicator of radioactive pollution in the marine environment due to its half-life (Tph: 30.2 years), its high fission yield, its solubility (70% in ionic form) and its bioavailability (similar to potassium). Soluble radionuclides, like 137Cs, in the seawater are associated with physicogeochemical and biological parameters of the marine environment (e.g. temperature, water density, biota exchange processes, water mass translocation etc.). Considering this characteristic, we investigate the potential relation between 137Cs activity concentration and sea surface temperature (SST). The parameter of SST is selected, as the element of cesium in the seawater is conservative and its horizontal and vertical dispersion depends on the water mass translocation and water currents. Water mass translocation and water currents are processes that are both governed by the SST. SST also influences the uptake of 137Cs in some marine organisms as it makes it more bioavailable and affects the biological retention time and the elimination rate. The study area is the Gulf of Corinth (Greece). Cs-137 in the Gulf of Corinth originates from water runnoff from the land (Chernobyl fallout from 1986) and a small influence exists from the Ionian and Aegean Sea water currents. A total of 17 measurements spanning 2004-2005, of 137Cs activity concentrations were retrieved from the Environmental Radioactivity Laboratory (ERL) database of NCSR “D”. Furthermore, SST measurements issued from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS). Databases of 137Cs activity concentrations and SST are used for regression analysis and definition of a linear model. The estimated 137Cs activity concentrations obtained by the model are then compared with the newest measured values obtained by seawater samples from September and November 2018 (a total of 8 seawater samples). Estimated concentrations present a relative difference of about 9% to the measured values. In order to conduct the risk assessment analysis in the studied area, the dose rates are calculated for marine organisms. The selected marine organisms are mussels and pelagic fish that are abundant in the area and have significant commercial value, with mussels also being an important bioindicator of marine pollution. The total dose rates in these organisms (resulting by both the internal and external exposure) vary from 3.30 × 101 to 5.40 × 101 μGy/year for the mussels and from 2.97 × 10-1 to 4.86 × 10-1 μGy/year for pelagic fish, which are much lower that the intervention levels, indicating low impact due to the 137Cs exposure.
{"title":"Dose rate assessment of 137Cs to mussels and pelagic fish from the combined use of field measurements, satellite data and the ERICA Assessment Tool","authors":"G. Mavrokefalou, M. Sotiropoulou","doi":"10.12681/hnps.3575","DOIUrl":"https://doi.org/10.12681/hnps.3575","url":null,"abstract":"Cesium-137 (137Cs) is the most important indicator of radioactive pollution in the marine environment due to its half-life (Tph: 30.2 years), its high fission yield, its solubility (70% in ionic form) and its bioavailability (similar to potassium). Soluble radionuclides, like 137Cs, in the seawater are associated with physicogeochemical and biological parameters of the marine environment (e.g. temperature, water density, biota exchange processes, water mass translocation etc.). Considering this characteristic, we investigate the potential relation between 137Cs activity concentration and sea surface temperature (SST). The parameter of SST is selected, as the element of cesium in the seawater is conservative and its horizontal and vertical dispersion depends on the water mass translocation and water currents. Water mass translocation and water currents are processes that are both governed by the SST. SST also influences the uptake of 137Cs in some marine organisms as it makes it more bioavailable and affects the biological retention time and the elimination rate. The study area is the Gulf of Corinth (Greece). Cs-137 in the Gulf of Corinth originates from water runnoff from the land (Chernobyl fallout from 1986) and a small influence exists from the Ionian and Aegean Sea water currents. A total of 17 measurements spanning 2004-2005, of 137Cs activity concentrations were retrieved from the Environmental Radioactivity Laboratory (ERL) database of NCSR “D”. Furthermore, SST measurements issued from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS). Databases of 137Cs activity concentrations and SST are used for regression analysis and definition of a linear model. The estimated 137Cs activity concentrations obtained by the model are then compared with the newest measured values obtained by seawater samples from September and November 2018 (a total of 8 seawater samples). Estimated concentrations present a relative difference of about 9% to the measured values. In order to conduct the risk assessment analysis in the studied area, the dose rates are calculated for marine organisms. The selected marine organisms are mussels and pelagic fish that are abundant in the area and have significant commercial value, with mussels also being an important bioindicator of marine pollution. The total dose rates in these organisms (resulting by both the internal and external exposure) vary from 3.30 × 101 to 5.40 × 101 μGy/year for the mussels and from 2.97 × 10-1 to 4.86 × 10-1 μGy/year for pelagic fish, which are much lower that the intervention levels, indicating low impact due to the 137Cs exposure.","PeriodicalId":262803,"journal":{"name":"HNPS Advances in Nuclear Physics","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123916723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kostantinos Korakas, Athanasia Miliadou, Theodora-Ilektra Katsigianni, Diamantis Tasioudis, N. Nicolis
Experimental excitation functions of isotopes produced in reactions are compared with the results of empirical cross section formulas. We consider excitation functions of 16 isotopes (36Cl, 38Ar, 42,43K, 44Ti, 46,47,48Sc, 48,51Cr, 52Fe, 52,54Mn and 55,56,57Co) produced in reactions at bombarding energies from threshold up to 2.6 GeV. They are compared with the predictions of the empirical formulas of Rudstam, Silberberg-Tsao and SPACS. In the middle-energy range, the formulas provide (in the stated order) a progressively improved description of the experimental excitation functions of the dominant isotopes. At the highest energies, the limiting values of the dominant excitation functions are well described by the EPAX formula (Version 2.1). The predictive power of these formulas could be questioned at low energies close to the threshold, reaction products with a mass much smaller than the target and possibly low cross section channels.
{"title":"Empirical Description of Isotope Production in 0.01-2.5GeV p+natFe Reactions","authors":"Kostantinos Korakas, Athanasia Miliadou, Theodora-Ilektra Katsigianni, Diamantis Tasioudis, N. Nicolis","doi":"10.12681/hnps.3620","DOIUrl":"https://doi.org/10.12681/hnps.3620","url":null,"abstract":"Experimental excitation functions of isotopes produced in reactions are compared with the results of empirical cross section formulas. We consider excitation functions of 16 isotopes (36Cl, 38Ar, 42,43K, 44Ti, 46,47,48Sc, 48,51Cr, 52Fe, 52,54Mn and 55,56,57Co) produced in reactions at bombarding energies from threshold up to 2.6 GeV. They are compared with the predictions of the empirical formulas of Rudstam, Silberberg-Tsao and SPACS. In the middle-energy range, the formulas provide (in the stated order) a progressively improved description of the experimental excitation functions of the dominant isotopes. At the highest energies, the limiting values of the dominant excitation functions are well described by the EPAX formula (Version 2.1). The predictive power of these formulas could be questioned at low energies close to the threshold, reaction products with a mass much smaller than the target and possibly low cross section channels.","PeriodicalId":262803,"journal":{"name":"HNPS Advances in Nuclear Physics","volume":"109 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123121565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Markopoulos, D. Mavrikis, E. Ntalla, A. Ioannidou, A. Savidou
The objective for decommissioning planning, is to obtain a radiological understanding of the involved installation. The characterization at this stage could be carried out by means of: (a) neutron activation calculations based on reactor design and neutron flux; (b) dose rate measurements; (c) in-situ gamma spectrometry; (d) sampling for determination of the scaling factors in activated and contaminated components.Neutron activation calculations contains several uncertainties. These uncertainties are based on the input data - such as material data (composition and impurities), neutron flux and energy, nuclear data libraries - and on the methodology of the process and the simulation codes.Taking into consideration all these modeling uncertainties, this work is focused on the development of a technique for validation of the calculations. A non-destructive gamma spectrometry technique by using MCNP6 simulations is under development for interpretation of the resulting gamma-ray spectra of the radionuclides in activated components. In particular, a spectrum will be produced, based on the activities of the main radionuclides in the activated component and the results of MCNP6 simulations. This spectrum will be compared with the experimental spectrum.Furthermore, the radiological characterization of activated components, which appeared with surface contamination, is essential for the decision making process during decommissioning. The cutting techniques to be followed in order to reduce the production of secondary waste and limit the doses to personnel and the selection of decontamination techniques should be based on accurate determination of the radionuclides inside the material and/ or in the surface contamination. The proposed method could also be helpful in this case. The activities inside and on the surface of the components could be determined by comparing the experimental spectrum with that produced by MCNP6 simulations, using the arisen activities from the scaling factors and the dose rate measurements.
{"title":"Comparison of Real and Generated by MCNP Simulation Spectrums for Validation of Neutron Activation Calculations","authors":"A. Markopoulos, D. Mavrikis, E. Ntalla, A. Ioannidou, A. Savidou","doi":"10.12681/hnps.3565","DOIUrl":"https://doi.org/10.12681/hnps.3565","url":null,"abstract":"The objective for decommissioning planning, is to obtain a radiological understanding of the involved installation. The characterization at this stage could be carried out by means of: (a) neutron activation calculations based on reactor design and neutron flux; (b) dose rate measurements; (c) in-situ gamma spectrometry; (d) sampling for determination of the scaling factors in activated and contaminated components.Neutron activation calculations contains several uncertainties. These uncertainties are based on the input data - such as material data (composition and impurities), neutron flux and energy, nuclear data libraries - and on the methodology of the process and the simulation codes.Taking into consideration all these modeling uncertainties, this work is focused on the development of a technique for validation of the calculations. A non-destructive gamma spectrometry technique by using MCNP6 simulations is under development for interpretation of the resulting gamma-ray spectra of the radionuclides in activated components. In particular, a spectrum will be produced, based on the activities of the main radionuclides in the activated component and the results of MCNP6 simulations. This spectrum will be compared with the experimental spectrum.Furthermore, the radiological characterization of activated components, which appeared with surface contamination, is essential for the decision making process during decommissioning. The cutting techniques to be followed in order to reduce the production of secondary waste and limit the doses to personnel and the selection of decontamination techniques should be based on accurate determination of the radionuclides inside the material and/ or in the surface contamination. The proposed method could also be helpful in this case. The activities inside and on the surface of the components could be determined by comparing the experimental spectrum with that produced by MCNP6 simulations, using the arisen activities from the scaling factors and the dose rate measurements.","PeriodicalId":262803,"journal":{"name":"HNPS Advances in Nuclear Physics","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122906127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Chasapoglou, M. Axiotis, G. Gkatis, S. Harissopulos, M. Kokkoris, A. Lagoyannis, C. Lederer-Woods, V. Michalopoulou, M. Savva, I. Stamatelatos, A. Stamatopoulos, T. Vasilopoulou, R. Vlastou
Τhe 70Ge(n,2n)69Ge, 72Ge(n,a)69mZn, 72Ge(n,p)72Ga and 73Ge(n,p)73Ga reactions have been measured by means of the activation technique at neutron energy 17.9 MeV. The quasimonoenergetic neutron beam was produced via the 2H(d,n)3He reaction at the 5.5 MV Tandem Van de Graaff accelerator of NCSR “Demokritos.” Isotopically highly enriched targets of 70Ge, 72Ge and 73Ge, provided by the nTOF collaboration at CERN, have been used, thus allowing accurate cross section measurements since no corrections are needed to compensate for the parasitic reactions from neighboring isotopes that exist in the case of using natural Ge target. The cross section has been deduced with respect to the 27Al(n,α)24Na reference reaction.
Τhe 70Ge(n,2n)69Ge、72Ge(n,a)69mZn、72Ge(n,p)72Ga和73Ge(n,p)73Ga反应在中子能17.9 MeV下进行了活化测量。在NCSR“Demokritos”的5.5 MV串联Van de Graaff加速器上，通过2H(d,n)3He反应产生准单能中子束。使用了由欧洲核子研究中心nTOF合作提供的同位素高度富集的70Ge、72Ge和73Ge靶，因此可以实现精确的横截面测量，因为在使用天然Ge靶时不需要校正邻近同位素的寄生反应。推导了27Al(n，α)24Na参考反应的截面。
{"title":"Cross Section Measurements of (n,x) Reactions at 17.9 MeV Using Highly Enriched Ge Isotopes","authors":"S. Chasapoglou, M. Axiotis, G. Gkatis, S. Harissopulos, M. Kokkoris, A. Lagoyannis, C. Lederer-Woods, V. Michalopoulou, M. Savva, I. Stamatelatos, A. Stamatopoulos, T. Vasilopoulou, R. Vlastou","doi":"10.12681/hnps.3621","DOIUrl":"https://doi.org/10.12681/hnps.3621","url":null,"abstract":"Τhe 70Ge(n,2n)69Ge, 72Ge(n,a)69mZn, 72Ge(n,p)72Ga and 73Ge(n,p)73Ga reactions have been measured by means of the activation technique at neutron energy 17.9 MeV. The quasimonoenergetic neutron beam was produced via the 2H(d,n)3He reaction at the 5.5 MV Tandem Van de Graaff accelerator of NCSR “Demokritos.” Isotopically highly enriched targets of 70Ge, 72Ge and 73Ge, provided by the nTOF collaboration at CERN, have been used, thus allowing accurate cross section measurements since no corrections are needed to compensate for the parasitic reactions from neighboring isotopes that exist in the case of using natural Ge target. The cross section has been deduced with respect to the 27Al(n,α)24Na reference reaction.","PeriodicalId":262803,"journal":{"name":"HNPS Advances in Nuclear Physics","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114861414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Peoviti, M. Axiotis, E. Georgali, S. Harissopulos, A. Lagoyannis, N. Patronis
Within the present work the HPGe detectors of the Institute of Nuclear and Particle Physics at NCSR “Demokritos” were fully characterized in terms of their efficiency. The three n-type 80% relative efficiency HPGe were recently acquired in the framework of the CALIBRA project. All detectors are equipped with carbon epoxy windows that allow detection of low energy γ-rays. Beside the efficiency characterization, the three detectors were fully modeled by means of GEANT4. In all cases the simulated detector geometries were fine-tuned so as to fully reproduce the experimental efficiency data at different source-to-detector distances. Finally, as a demonstration of the new offered abilities, the efficiency characterization and the GEANT4 modeling of the three HPGe detectors was used for a feasibility study of possible/future (n,2n) activation measurements on medium-weight nuclei.
{"title":"Characterisation of the new HPGe detectors at INPP/NCSR “Demokritos”... and future (n,2n) reactions to be studied","authors":"M. Peoviti, M. Axiotis, E. Georgali, S. Harissopulos, A. Lagoyannis, N. Patronis","doi":"10.12681/hnps.3580","DOIUrl":"https://doi.org/10.12681/hnps.3580","url":null,"abstract":"Within the present work the HPGe detectors of the Institute of Nuclear and Particle Physics at NCSR “Demokritos” were fully characterized in terms of their efficiency. The three n-type 80% relative efficiency HPGe were recently acquired in the framework of the CALIBRA project. All detectors are equipped with carbon epoxy windows that allow detection of low energy γ-rays. Beside the efficiency characterization, the three detectors were fully modeled by means of GEANT4. In all cases the simulated detector geometries were fine-tuned so as to fully reproduce the experimental efficiency data at different source-to-detector distances. Finally, as a demonstration of the new offered abilities, the efficiency characterization and the GEANT4 modeling of the three HPGe detectors was used for a feasibility study of possible/future (n,2n) activation measurements on medium-weight nuclei.","PeriodicalId":262803,"journal":{"name":"HNPS Advances in Nuclear Physics","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121162362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Draayer, D. Kekejian, G. Sargsyan, T. Dydtrych, R. Baker, K. Launey
A brief historical review of the important role symmetries have played in our gaining a deeper understanding nuclear structure is presented.We then focus our attention on the special role that symplectic symmetry plays in exposing a “Dominance of Deformation” that is found through enhanced B(E2) rates across the Chart of the Nuclides, and in addition, we will show how the No-Core Symplectic Shell Model (NC-SpSM) seems to emerge from a Symplectic Effective Field Theory(Sp-EFT), where the latter prepares away forward for gaining a truly ab initio understanding of the structure of atomic nuclei. As space permits, various spectra, B(E2) transition rates, and nuclear radii of selected light to medium-mass nuclei are shown.
{"title":"On the Dominance of Deformation in Nuclear Physics, its Link to Symplectic Symmetry, and its Roots in an Effective Field Theory","authors":"J. Draayer, D. Kekejian, G. Sargsyan, T. Dydtrych, R. Baker, K. Launey","doi":"10.12681/hnps.3613","DOIUrl":"https://doi.org/10.12681/hnps.3613","url":null,"abstract":"A brief historical review of the important role symmetries have played in our gaining a deeper understanding nuclear structure is presented.We then focus our attention on the special role that symplectic symmetry plays in exposing a “Dominance of Deformation” that is found through enhanced B(E2) rates across the Chart of the Nuclides, and in addition, we will show how the No-Core Symplectic Shell Model (NC-SpSM) seems to emerge from a Symplectic Effective Field Theory(Sp-EFT), where the latter prepares away forward for gaining a truly ab initio understanding of the structure of atomic nuclei. As space permits, various spectra, B(E2) transition rates, and nuclear radii of selected light to medium-mass nuclei are shown.","PeriodicalId":262803,"journal":{"name":"HNPS Advances in Nuclear Physics","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121765355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the current study we briefly review the advantages of utilising elastic neutron scattering techniques to reveal the structure of porous materials and pore-confined fluids. Furthermore, we highlight the benefits of utilising in situ CO2 injection and neutron scattering in model porous systems as well as in sedimentary rocks to explore the pore morphology, the pore accessibility and the structural properties of pore-confined CO2. This information is important for the design of optimal CO2 sequestration as well as gas and oil recovery projects.
{"title":"Neutron Scattering from Porous Materials and Confined Fluids: Applications to CO2 Sequestration and Oil Recovery","authors":"K. Stefanopoulos","doi":"10.12681/hnps.3579","DOIUrl":"https://doi.org/10.12681/hnps.3579","url":null,"abstract":"In the current study we briefly review the advantages of utilising elastic neutron scattering techniques to reveal the structure of porous materials and pore-confined fluids. Furthermore, we highlight the benefits of utilising in situ CO2 injection and neutron scattering in model porous systems as well as in sedimentary rocks to explore the pore morphology, the pore accessibility and the structural properties of pore-confined CO2. This information is important for the design of optimal CO2 sequestration as well as gas and oil recovery projects.","PeriodicalId":262803,"journal":{"name":"HNPS Advances in Nuclear Physics","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129861217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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