| 1. |
- Andersson, Peter, 1981-, et al.
(författare)
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Coincidence spectroscopy for increased sensitivity in radionuclide monitoring
- 2022
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The majority of the energy in a nuclear explosion is released in the immediate blast and the initial radiation accounts. The remaining fraction is released through radioactive decay of the explosion's fission products and neutron activation products over a longer time span. This allows for the detection of a nuclear explosion by detecting the presence of residual decay. Radionuclide monitoring stations for detection of radioactive emissions to the atmosphere is thereby an important tool in the verification of compliance with nuclear disarmament treaties. In particular, the globally spanning radionuclide station network of the International Monitoring System (IMS) has been implemented for verification of the Comprehensive Nuclear-Test-Ban Treaty.High Purity Germanium (HPGe) detectors are workhorses in radionuclide monitoring. The detection of characteristic gamma rays can be used to disclose the presence of signature nuclides produced innuclear weapon tests. A particular development that has potential to improve the sensitivity of radionuclide monitoring is the coincidence technique where decaying nuclides that emit several coincident gamma rays can be detected at much smaller activity concentrations than with conventional gamma spectroscopy.In this project, dedicated gamma-gamma coincidence detectors are being developed, utilizing electronically segmented HPGe detectors. These detectors are expected to be highly sensitive to low-activity samples of nuclides that present coincident emissions of gamma rays. In this paper we present the concept, define performance parameters, and explore the performance of such detectors to a subset of radionuclides of particular CTBT relevance. In addition, we discuss the path forward in developing a next generation gamma-gamma coincidence spectroscopy system of segmented HPGe.
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| 2. |
- Barucca, G., et al.
(författare)
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Feasibility studies for the measurement of time-like proton electromagnetic form factors from (p)over-barp -> mu(+)mu(-) at PANDA at FAIR
- 2021
-
Ingår i: European Physical Journal A. - NEW YORK, USA : Springer Nature. - 1434-6001 .- 1434-601X. ; 57:1
-
Tidskriftsartikel (refereegranskat)abstract
- This paper reports on Monte Carlo simulation results for future measurements of the moduli of time-like proton electromagnetic form factors, vertical bar G(E)vertical bar and vertical bar G(M)vertical bar, using the (p) over barp -> mu(+)mu(-) reaction at PANDA (FAIR). The electromagnetic form factors are fundamental quantities parameterizing the electric and magnetic structure of hadrons. This work estimates the statistical and total accuracy with which the form factors can be measured at PANDA, using an analysis of simulated data within the PandaRoot software framework. The most crucial background channel is (p) over barp -> pi(+)pi(-), due to the very similar behavior of muons and pions in the detector. The suppression factors are evaluated for this and all other relevant background channels at different values of antiproton beam momentum. The signal/background separation is based on a multivariate analysis, using the Boosted Decision Trees method. An expected background subtraction is included in this study, based on realistic angular distributions of the background contribution. Systematic uncertainties are considered and the relative total uncertainties of the form factor measurements are presented.
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| 3. |
- Barucca, G., et al.
(författare)
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PANDA Phase One
- 2021
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Ingår i: European Physical Journal A. - : Springer Nature. - 1434-6001 .- 1434-601X. ; 57:6
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Tidskriftsartikel (refereegranskat)abstract
- The Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany, provides unique possibilities for a new generation of hadron-, nuclear- and atomic physics experiments. The future antiProton ANnihilations at DArmstadt (PANDA or PANDA) experiment at FAIR will offer a broad physics programme, covering different aspects of the strong interaction. Understanding the latter in the non-perturbative regime remains one of the greatest challenges in contemporary physics. The antiproton-nucleon interaction studied with PANDA provides crucial tests in this area. Furthermore, the high-intensity, low-energy domain of PANDA allows for searches for physics beyond the Standard Model, e.g. through high precision symmetry tests. This paper takes into account a staged approach for the detector setup and for the delivered luminosity from the accelerator. The available detector setup at the time of the delivery of the first antiproton beams in the HESR storage ring is referred to as the Phase One setup. The physics programme that is achievable during Phase One is outlined in this paper.
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| 4. |
- Barucca, G., et al.
(författare)
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Precision resonance energy scans with the PANDA experiment at FAIR : Sensitivity study for width and line shape measurements of the X(3872)
- 2019
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Ingår i: European Physical Journal A. - : SPRINGER. - 1434-6001 .- 1434-601X. ; 55:3
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Tidskriftsartikel (refereegranskat)abstract
- This paper summarises a comprehensive Monte Carlo simulation study for precision resonance energy scan measurements. Apart from the proof of principle for natural width and line shape measurements of very narrow resonances with PANDA, the achievable sensitivities are quantified for the concrete example of the charmonium-like X(3872) state discussed to be exotic, and for a larger parameter space of various assumed signal cross-sections, input widths and luminosity combinations. PANDA is the only experiment that will be able to perform precision resonance energy scans of such narrow states with quantum numbers of spin and parities that differ from JPC=1--.
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| 5. |
- Barucca, G., et al.
(författare)
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Study of excited Ξ baryons with the P¯ ANDA detector
- 2021
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Ingår i: European Physical Journal A. - : Springer Nature. - 1434-6001 .- 1434-601X. ; 57:4
-
Tidskriftsartikel (refereegranskat)abstract
- The study of baryon excitation spectra provides insight into the inner structure of baryons. So far, most of the world-wide efforts have been directed towards N∗ and Δ spectroscopy. Nevertheless, the study of the double and triple strange baryon spectrum provides independent information to the N∗ and Δ spectra. The future antiproton experiment P¯ANDA will provide direct access to final states containing a Ξ¯ Ξ pair, for which production cross sections up to μb are expected in p¯p reactions. With a luminosity of L= 10 31 cm- 2 s- 1 in the first phase of the experiment, the expected cross sections correspond to a production rate of ∼106events/day. With a nearly 4 π detector acceptance, P¯ANDA will thus be a hyperon factory. In this study, reactions of the type p¯p → Ξ¯ +Ξ∗ - as well as p¯p → Ξ¯ ∗ +Ξ- with various decay modes are investigated. For the exclusive reconstruction of the signal events a full decay tree fit is used, resulting in reconstruction efficiencies between 3 and 5%. This allows high statistics data to be collected within a few weeks of data taking.
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| 6. |
- Barucca, G., et al.
(författare)
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The potential of Λ and Ξ- studies with PANDA at FAIR
- 2021
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Ingår i: European Physical Journal A. - : Springer Nature. - 1434-6001 .- 1434-601X. ; 57:4
-
Tidskriftsartikel (refereegranskat)abstract
- The antiproton experiment PANDA at FAIR is designed to bring hadron physics to a new level in terms of scope, precision and accuracy. In this work, its unique capability for studies of hyperons is outlined. We discuss ground-state hyperons as diagnostic tools to study non-perturbative aspects of the strong interaction, and fundamental symmetries. New simulation studies have been carried out for two benchmark hyperon-antihyperon production channels: p¯ p→ Λ¯ Λ and p¯ p→ Ξ¯ +Ξ-. The results, presented in detail in this paper, show that hyperon-antihyperon pairs from these reactions can be exclusively reconstructed with high efficiency and very low background contamination. In addition, the polarisation and spin correlations have been studied, exploiting the weak, self-analysing decay of hyperons and antihyperons. Two independent approaches to the finite efficiency have been applied and evaluated: one standard multidimensional efficiency correction approach, and one efficiency independent approach. The applicability of the latter was thoroughly evaluated for all channels, beam momenta and observables. The standard method yields good results in all cases, and shows that spin observables can be studied with high precision and accuracy already in the first phase of data taking with PANDA.
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| 7. |
- Branger, Erik, 1988-, et al.
(författare)
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Combining DCVD measurements at different alignments for enhanced partial defect detection performance
- 2021
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Ingår i: Proceedings of the INMM & ESARDA Joint Virtual Annual Meeting August 23-26 & August 30-September 1, 2021.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In the current Digital Cherenkov Viewing Device (DCVD) measurement methodology, the DCVD is aligned over the centre of a fuel assembly when measuring emitted Cherenkov light. Due to the collimation of light, and due to the lifting handle of PWR fuel assemblies covering the fuel periphery, the DCVD is more sensitive to partial defects near the fuel assembly centre than near the periphery. Here, we investigate the sensitivity of the DCVD for detecting partial defects for different instrument alignments. By performing measurements at both the centre and near the assembly periphery, more accurate measurements near the periphery can be obtained.DCVD images were simulated for different partial defect scenarios with 30% of the fuel rods removed or replaced with low, medium or high-density rods. Simulations were run with different DCVD alignments, and the Cherenkov light distribution in the images were quantitatively analysed and compared to simulated images for a fuel assembly without defects. The simulation results were also compared with measurements of intact spent fuel assemblies.The simulations show that the local Cherenkov light intensity deviation due to a partial defect is not sensitive to the alignment. Hence, the current methodology is robust, and will not benefit from measuring at different alignments. Regarding the signal-to-noise ratio, combining measurements at different alignments can improve the measurements. However, the improvement is modest, and for the DCVD it may be preferred to simply use the current methodology and make longer measurements. For future autonomous Cherenkov measuring systems, combining images can be a way of improving the quality of the measurements.
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| 8. |
- Branger, Erik, 1988-, et al.
(författare)
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Effects of modelling assumptions on Cherenkov light intensity predictions
- 2022
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The Digital Cherenkov Viewing Device (DCVD) is one of the instruments available to IAEA inspectors to verify spent nuclear fuel in wet storage. The DCVD can be used for partial defect verification, verifying that 50% or more of a fuel assembly has not been diverted. The partial defect verification relies on a comparison between measured and predicted intensities, based on operator fuel declarations. Recently, IAEA inspectors have encountered spent fuels with short cooling times where there were systematic differences between predictions and measurements. Through the Swedish support program, this deviation was investigated, by studying various modelling assumptions that could cause the discrepancy.The predominant cause of the discrepancy was beta-decay electrons, passing through the fuel cladding and entering the water with sufficient energy to directly produce Cherenkov light. Analysis of measurement data for a set of fuels where the discrepancy was found to be pronounced revealed that for modern fuel designs with thin claddings the beta contribution is enhanced, and for short-cooled fuels additional beta-decaying isotopes are abundant and must be considered. Furthermore, the data showed that for nuclear fuels that had not reached the discharge burnup, the fuel irradiation history may cause a relative enhancement of the abundance of beta-decaying isotopes relative to other isotopes causing Cherenkov light. Other studied modelling assumptions, such as void, burnable absorbers and using binned gamma spectra, showed that they only introduced a modest bias, and proper default values and data handling can mitigate it. A method to predict the direct beta contribution to the Cherenkov light intensity was developed, which can ensure that the observed biases will be eliminated from future verification campaigns. It is advised that this enhanced prediction method be included in the DCVD software, and made available to inspectors.
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| 9. |
- Branger, Erik, 1988-, et al.
(författare)
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Image analysis to support DCVD verification
- 2023
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Ingår i: Proceedings of the INMM & ESARDA Joint Annual Meeting, May 22-26, 2023. - : Institute of Nuclear Materials Management (INMM).
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The Digital Cherenkov Viewing Device (DCVD) is one instrument available to authority inspectors for verifying spent fuel assemblies in wet storage. The measurements result in images of the Cherenkov light emissions from the fuel assembly under study. This work presents research on applying image analysis and statistical methods to improve data quality and to extract more information from the measurements, extending the use of these methods beyond what is currently implemented in the DCVD software. The goal of this project is to apply template matching and statistical analysis to the images. However, before such techniques can be applied, effort is needed to ensure that the measurements are directly comparable. Two main issues are investigated here, the first being the positioning of the Region-Of-Interest. By developing an automated Region-Of-Interest placer, a consistent and reproducible Region-Of-Interest placement can be achieved. The second is automatic identification of fuel type, to support a later comparison with a template. We demonstrate that a method based on Principal Component Analysis can be used to determine the fuel type. Finally, we present the first results regarding template matching, comparing a measured image to a template, aiming to identify regions in the image where the two differ. Such differences could be due to a partial defect located in that region, but also due to other reasons such as debris covering the fuel top. Automatically identification of such regions can in the future be used to focus inspector attention to features requiring expert judgement, supporting efficient use of the measurement data and inspector effort. The first results demonstrate the feasibility of the method, but also that more work is required before the method is robust.
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| 10. |
- Branger, Erik, 1988-, et al.
(författare)
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Investigating the sensitivity to irradiation history when predicting fuel parameters using random forest regression
- 2021
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Ingår i: ESARDA Bulletin. - : European Commission Joint Research Centre. - 1977-5296. ; 62, s. 2-10
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Tidskriftsartikel (refereegranskat)abstract
- Safeguards verification of spent nuclear fuel assemblies is frequently done by performing non-destructive measurements, which are used to verify the completeness and correctness of operator declarations such as initial enrichment (IE), burnup (BU) and cooling time (CT) of the fuel. However, different irradiation histories may result in the same combination of CT, BU and IE, and such fuels may behave differently despite identically declared values. The goal of this work is to investigate what effect the irradiation history has on the ability to predict the fuel parameters using random forest regression. Random forest regression models were trained to predict the fuel parameters IE, BU and CT based on combinations of radiation signatures calculated from a previously modelled Pressurised Water Reactor (PWR) spent nuclear fuel library. The radiation signatures studied were the relative gamma-ray activities of Cs137, Cs134 and Eu154, their total gamma-ray activity, the total neutron emission rate and the parametrized early die-away time ? from the Differential Die-away Self Interrogation (DDSI) instrument. The performance of the models were tested on simulations of 2192 PWR fuel assemblies from the Ringhals 3 and 4 nuclear power plants in Sweden, which were simulated based on their documented irradiation histories. Despite significant differences in irradiation history between the training and testing data sets, the Ringhals assembly parameters could be predicted with similar accuracy as for assemblies in the training set. The relative gamma-ray activities were sufficient to predict the CT with an RMSE of 2 years, and adding a total gamma or total neutron signature allowed the BU to be predicted with an RMSE of 1.4 MWd/kgU. The DDSI early die-away time ? enabled an accurate IE prediction, with an RMSE of 0.16 w%. The differences between irradiation histories introduced a systematic bias where CT was overestimated by about 1 year and the BU by about 1.5 MWd/kgU.
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| 11. |
- Branger, Erik, 1988-, et al.
(författare)
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Studies of the impact of beta contributions on Cherenkov light emission by spent nuclear fuel
- 2022
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Ingår i: ESARDA Bulletin. - : ESARDA. - 1977-5296. ; 64:1, s. 2-9
-
Tidskriftsartikel (refereegranskat)abstract
- The Digital Cherenkov Viewing Device (DCVD) is one of the instruments used by safeguards inspectors to verify spent nuclear fuel in wet storage. The DCVD can be used for partial defect verification, where the inspectors verify that 50% or more of an assembly has not been diverted. The methodology is based on comparing the measured Cherenkov light intensity with a predicted intensity, calculated with operator information.Recently, IAEA inspectors have encountered fuel assemblies for which systematic deviations between predictions and measurements could be observed, indicating that the prediction model did not take into account all sources of Cherenkov light production. One contribution to the Cherenkov light intensity that is frequently omitted is the contribution from beta decays, where energetic electrons exit the fuel material and enter the water with sufficient energy to directly produce Cherenkov light. The objective with this work was hence to study beta contributions and evaluate whether that could be the cause of discrepancy between predictions and experimental data.By simulating the beta contribution for fuel assemblies where the discrepancy was experimentally observed, it was determined that beta decays were the cause. The fuel assemblies had fuel rods with relatively small radii, thin cladding, a short cooling time and an irradiation history that resulted in a relatively large beta contribution for assemblies that had a comparatively low burnup. Therefore, the beta contribution was significant, and caused 10-40% of the total Cherenkov light intensity. By including the beta contributions in the predictions, the RMSE of the deviation between prediction and measurement could be reduced from 20.7% to 11.6% for the available measurement data. The results highlight that the beta contribution can be significant and should be taken into account for accurate predictions.
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| 12. |
- Campbell, PJ, et al.
(författare)
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Pan-cancer analysis of whole genomes
- 2020
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 578:7793, s. 82-
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Tidskriftsartikel (refereegranskat)abstract
- Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale1–3. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4–5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter4; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation5,6; analyses timings and patterns of tumour evolution7; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity8,9; and evaluates a range of more-specialized features of cancer genomes8,10–18.
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| 13. |
- Collaboration, The PANDA, et al.
(författare)
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Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR
- 2016
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Ingår i: European Physical Journal A. - : Springer Publishing Company. - 1434-6001 .- 1434-601X. ; 52:10
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Tidskriftsartikel (refereegranskat)abstract
- Simulation results for future measurements of electromagnetic proton form factors at P ¯ ANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel p¯ p→ e+e- is studied on the basis of two different but consistent procedures. The suppression of the main background channel, i.e.p¯ p→ π+π-, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance.
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| 14. |
- Davi, F., et al.
(författare)
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Technical design report for the endcap disc DIRC
- 2022
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Ingår i: Journal of Physics G. - : Institute of Physics Publishing (IOPP). - 0954-3899 .- 1361-6471. ; 49:12
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Tidskriftsartikel (refereegranskat)abstract
- PANDA (anti-proton annihiliation at Darmstadt) is planned to be one of the four main experiments at the future international accelerator complex FAIR (Facility for Antiproton and Ion Research) in Darmstadt, Germany. It is going to address fundamental questions of hadron physics and quantum chromodynamics using cooled antiproton beams with a high intensity and and momenta between 1.5 and 15 GeV/c. PANDA is designed to reach a maximum luminosity of 2 × 1032 cm−2 s. Most of the physics programs require an excellent particle identification (PID). The PID of hadronic states at the forward endcap of the target spectrometer will be done by a fast and compact Cherenkov detector that uses the detection of internally reflected Cherenkov light (DIRC) principle. It is designed to cover the polar angle range from 5° to 22° and to provide a separation power for the separation of charged pions and kaons up to 3 standard deviations (s.d.) for particle momenta up to 4 GeV/c in order to cover the important particle phase space. This document describes the technical design and the expected performance of the novel PANDA disc DIRC detector that has not been used in any other high energy physics experiment before. The performance has been studied with Monte-Carlo simulations and various beam tests at DESY and CERN. The final design meets all PANDA requirements and guarantees sufficient safety margins.
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| 15. |
- dos Santos Matias, Lucilio, et al.
(författare)
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Characterization of the radiation field surrounding the Leksell Gamma Knife® and shielding applications
- 2023
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Ingår i: Applied Radiation and Isotopes. - 0969-8043 .- 1872-9800. ; 198
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study is to improve the characterization and modeling of the radiation field surrounding the Leksell Gamma Knife®-PerfexionTM. The improved characterization of the radiation field enables more accurate shielding calculations to be performed for the areas adjacent to the treatment room. With the aid of a high-purity germanium detector and a satellite dose rate meter, ?-ray spectra and ambient dose equivalent H*(10) data were acquired at various locations in the field of a Leksell Gamma Knife unit in a treatment room at Karolinska University Hospital, Sweden. These measurements were used to validate the results of the PEGASOS Monte Carlo simulation system with a PENELOPE kernel. The levels of the radiation that passes through the shielding of the machine (leakage radiation) are shown to be much lower than what is suggested by various bodies, e.g. the National Council on Radiation Protection and Measurements, to be used when calculating radiation shielding barriers. The results clearly indicate that Monte Carlo simulations may be used in structural shielding design calculations for γ? rays from the Leksell Gamma Knife.
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| 16. |
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| 17. |
- Grape, Sophie, 1982-, et al.
(författare)
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Non-proliferation and safeguards activities within the Alva Myrdal Centre for nuclear disarmament
- 2022
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Ingår i: Proceedings of the Symposium on International Safeguards: Reflecting on the Past and Anticipating the Future.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In 2020, the Swedish government announced the intent to start up a national competence centre on nuclear disarmament in Sweden. The goal was to highlight the importance of nuclear disarmament issues, and to promote research, teaching and policy support on topics relevant to nuclear disarmament. During the spring semester 2021, the Alva Myrdal Centre (AMC) on nuclear disarmament was established at Uppsala University. The AMC combines competences from different disciplines such as peace and conflict research, applied nuclear physics, and international law, and organises the work into six different working groups. One of the working groups is focusing on technical aspects, while the remaining five working groups are focusing on policy aspects. The technical working group is led by the Division of Applied Nuclear Physics at Uppsala University, where research on nuclear safeguards has been performed for over 30 years, and where competence in addition exists on a number of applied physics applications ranging from nuclear reactions, nuclear power and detection of radionuclides.
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| 18. |
- Grape, Sophie, 1982-, et al.
(författare)
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State-of-the-Art Report : Prepared by Working Group 4: Technical nuclear non-proliferation and safeguards under the Alva Myrdal Centre for nuclear disarmament
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The Alva Myrdal Centre for nuclear disarmament (AMC) was established in 2021. AMC consists of six working Groups, and one of them - Working Group 4 - is called Technical nuclear non-proliferation and safeguards. This is the State-of-the-Art Report of that working group. The objective with the report is to provide an overview of the technical fields relevant to the working group and to highlight where research and activities within the working group may contribute to global nuclear disarmament. The report gives a brief explanation of actors in the field, introduces nuclear materials and assay techniques, and then continues to elaborate on challenges and needs associated with nuclear measurements and assessments in the fields of non-proliferation, nuclear safeguards and nuclear disarmament. A section is also devoted to the management of nuclear weapons materials after disarmament. Lastly, the report contains a section on interdisciplinary research and development in nuclear disarmament, and information about technical education and training in the non-proliferation and disarmament field.
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| 19. |
- Gustavsson, Cecilia, Dr, 1973-, et al.
(författare)
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A technical view on Pakistan's nuclear weapons programme
- 2022
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Pakistan performed at least two nuclear weapons tests in 1998 as a direct response to the Indian nuclear tests earlier the same year. With this act, Pakistan became the seventh country to successfully complete a nuclear weapons programme. The Pakistani nuclear weapons arsenal consists of both uranium and plutonium weapons and the country has an extensive nuclear industry with all facilities necessary for enrichment of uranium, production of plutonium and reprocessing of spent reactor fuel.Pakistan acquired a Canadian civil heavy water nuclear reactor in 1971; KANUPP-1. In 1976 however, the cooperation with Canada ended as Canada stopped supplying fuel for the reactor. At this point, Pakistan had acquired know-how and experience to manufacture its own fuel and also started building an independent nuclear industry with several unsafeguarded reactors at the Khushab site. With French assistance, a reprocessing plant was constructed and consequently, Pakistan is today in possession of all components necessary for developing and employing both uranium and plutonium nuclear devices. In this presentation, we will explore technical challenges associated with bringing a country such as Pakistan under the existing or proposed treaty verification following treaties such as the NPT, TPNW and FMCT. Using a simulation framework and estimates based on known physical quantities and derived abilities, we will discuss what conclusions can be drawn with regards to uranium and plutonium stockpiles.
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| 20. |
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| 21. |
- Makonyi, Karoly, et al.
(författare)
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Feasibility study for the measurement of πN transition distribution amplitudes at ¯PANDA in ¯pp→J/ψπ0
- 2017
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Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 95:3
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Tidskriftsartikel (refereegranskat)abstract
- The exclusive charmonium production process in (P) over barp annihilation with an associated pi 0 meson (p) over barp -> J/psi pi(0) is studied in the framework of QCD collinear factorization. The feasibility of measuring this reaction through the J/psi -> e(+) e(-) decay channel with the AntiProton ANnihilation at DArmstadt ((P) over bar ANDA) experiment is investigated. Simulations on signal reconstruction efficiency as well as the background rejection from various sources including the (P) over barp -> pi(+)pi(-)pi(0) and (p) over barp -> J/psi pi(0)pi(0) reactions are performed with PANDAROOT, the simulation and analysis software framework of the (P) over bar ANDA experiment. It is shown that the measurement can be done at (P) over bar ANDA with significant constraining power under the assumption of an integrated luminosity attainable in four to five months of data taking at the maximum design luminosity.
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| 22. |
- Mishra, Vaibhav, Doktorand, 1989-, et al.
(författare)
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Assessments of radiation emission from molten salt reactor spent fuel: Implications for future nuclear safeguards verification
- 2023
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Safeguards verification using non-destructive assay (NDA) techniques is an important pillar of the safeguards regime to ensuring that nuclear technology is not used for non-peaceful purposes. The methods and approaches for safeguards verification for conventional spent nuclear fuel (SNF) originating from the global fleet of water-cooled reactors are well-established. However, for reactors such as molten salt reactors (MSR), accountancy verification method of irradiated fuel salts is not quite well-established. This is primarily since the irradiated salt is in “bulk form” whereas more conventional LWR SNF encountered by the safeguards inspectors is in “item form”. Moreover, much about the nature of such SNF still remains unknown due to the lack of operational MSRs and equipment adequate to further study, develop and test NDA verification methods.As MSRs could play a complementary role with the existing fleet of reactors in the near future, verification methods concerning the nature of emissions from irradiated fuel salts is timely. Therefore, in this current study we aim to quantify and study the nature of gamma and neutron emissions as well as decay heat production in irradiated fuel salt from the Compact Molten Salt Reactor (CMSR) developed by Seaborg Technologies in Denmark. Simulations were carried out using the Monte-Carlo particle transport code Serpent as well as the code SOURCES 4C to compute nuclide inventories and the associated emission rates of gamma and neutron (from spontaneousfissions, or SF and from (α, n) reactions) emissions and decay heat calculations. These results willshed more light on the implications for nuclear safeguards verification for irradiated fuel salts andalso highlight some of the challenges and opportunities associated with detecting and characterizingthe emissions using NDA methods in the future for SNF of such unique nature.
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| 23. |
- Mitola, Joseph, et al.
(författare)
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Software defined radio-20 years later : Part 1
- 2016
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Ingår i: IEEE Communications Magazine. - : Institute of Electrical and Electronics Engineers (IEEE). - 0163-6804 .- 1558-1896. ; 54:1, s. 58-58
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 24. |
- Preston, Markus, et al.
(författare)
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A feature-extraction and pile-up reconstruction algorithm for the forward-spectrometer EMC of the PANDA experiment
- 2021
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 1011
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Tidskriftsartikel (refereegranskat)abstract
- A digital algorithm for real-time feature extraction, i.e. determination of pulse amplitude and timing, has been developed for the forward-spectrometer electromagnetic calorimeter in the PANDA experiment. The algorithm, which is based on the well known optimal-filter algorithm, has been designed to allow reconstruction of pile-up signals in real time and to work in a free-running DAQ system such as PANDA. To benchmark the algorithm, a Geant4-based Monte Carlo model of photon interactions in the calorimeter has been developed to generate realistic detector signals which were used as inputs to a VHDL simulation of the algorithm. The results of this simulation study show that the developed algorithm improves the time resolution by almost 50% compared to a conventional linear constant fraction discriminator algorithm. For the PANDA calorimeter, this results in a time root resolution close to 100 ps/ GeV per detector element at high energies. The algorithm allows reconstruction of the amplitude and timing of pile-up pulses separated by as little as 30 ns with good efficiency, fulfilling the PANDA requirements.
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| 25. |
- Preston, Markus, et al.
(författare)
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Analysis of radiation emission from MYRRHA spent fuel and implications for non-destructive safeguards verification
- 2021
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Ingår i: Annals of Nuclear Energy. - : Elsevier. - 0306-4549 .- 1873-2100. ; 163, s. 108525-
-
Tidskriftsartikel (refereegranskat)abstract
- The radionuclide composition of, and emitted radiation in, spent nuclear fuel from the future MYRRHA facility have been studied using depletion simulations to understand potential consequences for safeguards verification using non-destructive assay. The simulations show that both the gamma-ray and neutron emission rates in spent MYRRHA assemblies are lower than in spent PWR UO2 and MOX assemblies. In addition, gamma-ray emission rates from 134Cs and 154Eu are considerably lower, and the total neutron emission rate in MYRRHA fuel is much less sensitive to fuel burnup and cooling time. The main reason is that the fast neutron spectrum in MYRRHA affects the radionuclide production in the fuel. One result is that 244Cm, the main contributor to the neutron emission in spent light water reactor fuel, has a limited production in MYRRHA. Consequently, neutron-detection techniques could be used to more directly assay the plutonium content of spent MYRRHA fuel.
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| 26. |
- Preston, Markus, 1989-
(författare)
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Developments for the FPGA-Based Digitiser in the PANDA Electromagnetic Calorimeters
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The strong interaction between quarks and gluons is one of the fundamental interactions described by the standard model of particle physics. Systems of quarks bound together by the strong interaction are known as hadrons, of which the proton and the neutron are the most common examples. The theoretical framework of quantum chromodynamics (QCD) is used to describe the strong interaction, but becomes increasingly difficult to use as the distance between the interacting particles increases. On the length scales relevant for hadrons, for instance, non-perturbative approaches to QCD have to be used. Experimental data are needed to verify these approaches. PANDA is one of the four experimental pillars of the upcoming FAIR facility in Darmstadt, Germany. In PANDA, an antiproton beam with a momentum between 1.5 and 15 GeV/c will interact in a hydrogen or nuclear target, allowing studies of various aspects of non-perturbative QCD. Motivated by the high interaction rates and the diverse physics goals of the experiment, a triggerless readout approach will be employed. In this approach, each detector subsystem will be equipped with intelligent front-end electronics that independently identify signals of interest in real time. In the electromagnetic calorimeter, FPGA-based digitiser modules will be used for this task. The high-radiation environment in PANDA will pose a challenge to these modules, due to both potential radiation damage and high signal rates from the calorimeter. In this thesis, these issues are addressed. First, the results from experimental measurements and Monte Carlo modelling of radiation-induced single event upsets in the FPGA are described. These studies have allowed predictions of the rate of single event upsets during operation of PANDA. Secondly, a newly developed algorithm for real-time processing of calorimeter signals in an FPGA at high pile-up rates is described. This algorithm provides a significant improvement in the time resolution of the calorimeter and allows reconstruction of the pulse height and timing of piled-up detector signals.
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| 27. |
- Preston, Markus, et al.
(författare)
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Discriminating Between Irradiated MYRRHA Fuel and Light Water Reactor Fuels Using Gamma Rays and Neutrons
- 2021
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Ingår i: Proceedings of the INMM & ESARDA Joint Virtual Annual Meeting August 23-26 & August 30-September 1, 2021, 2021.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- MYRRHA is an accelerator-driven system featuring a MOX-fuelled core cooled by lead-bismuth eutectic, which is under development at SCK CEN in Mol, Belgium. An initial plutonium content of 30% in the fuel is foreseen, which together with the fast neutron spectrum in the core results in considerably different spent-fuel properties compared to spent fuel from typical lightwater reactors. These differences have been studied through depletion simulations, and include how radionuclide densities depend on burnup, which radionuclides contribute to the gamma-ray and neutron emission, and the intensity of the emitted radiation. As a consequence, current techniques for safeguards verification of spent fuel via non-destructive assay may need to be updated, or new techniques developed, for use in safeguarding of spent MYRRHA fuel. To some extent, these differences may have consequences in the wider context of nuclear safeguards for Generation IV systems. The focus of this paper is to investigate to what extent the gamma-ray and neutron signatures could be used to differentiate irradiated MYRRHA fuel from irradiated MOX and UO2 fuels from a light water reactor. The ability to discriminate between light-water-reactor MOX and UO2 has been recognised as an important task in safeguards verification today, and this work extends this objective to a future nuclear energy system.
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| 28. |
- Preston, Markus, et al.
(författare)
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FPGA-based algorithms for feature extraction in the PANDA shashlyk calorimeter
- 2020
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Ingår i: Journal of Instrumentation. - : IOP PUBLISHING LTD. - 1748-0221. ; 15:8
-
Tidskriftsartikel (refereegranskat)abstract
- PANDA is one of the four experimental pillars of the upcoming FAIR facility in Darmstadt, Germany. In PANDA, an antiproton beam with an energy between 1.5 and 15 GeV/c will interact in a hydrogen or nuclear target, allowing for studies of various aspects of non-perturbative QCD. Motivated by the high interaction rates and the diverse physics goals of the experiment, a triggerless readout approach will be employed. In this approach, each detector subsystem will be equipped with intelligent front-end electronics that independently identify signals of interest in real time. In order to detect the most forward-directed photons, electrons and positrons in PANDA, a shashlyk-type calorimeter is being constructed. This detector consists of 1512 individual cells of interleaved plastic scintillators and lead plates, and the output signals will be digitised by sampling ADCs and processed in real time by FPGAs. As part of the triggerless approach, these FPGAs will perform so-called feature extraction on the digitised signals, where the pulse-height and time of incoming pulses are extracted in real time. A substantial pile-up rate is expected, and it is foreseen that the chosen algorithm should enable reconstruction of such events. In this work we present the development of a real-time algorithm based on the well known Optimal Filter, which both improves the overall time resolution of the shashlyk detector and allows reconstruction of pile-up events with good time and energy resolution.
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| 29. |
- Preston, Markus, et al.
(författare)
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Measurements and Simulations of Single-Event Upsets in a 28-nm FPGA
- 2017
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Ingår i: Proceedings of Science. - Trieste, Italy : Sissa Medialab. - 1824-8039. ; 313
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Tidskriftsartikel (refereegranskat)abstract
- Single-event upsets in the configuration memory of the 28-nm Xilinx Kintex-7 FPGA, used in the PANDA electromagnetic calorimeter, have been studied. Results from neutron and proton irradiations at energies up to 184 MeV are presented and compared with previous experimental results. In order to gain information about the energy-dependence of the single-event upset cross section, a GEANT4-based Monte Carlo simulation of upset mechanisms in nanometric silicon volumes has been developed. The results from this model are shown to agree with the experimental data for both neutrons and protons. Knowledge about the energy dependence of the cross section and of the particle flux at the location of the front-end modules in PANDA enables better estimates of the mean time between failures in the electromagnetic calorimeter. At PANDA, a total neutron flux of 1·102 cm−2 s−1 at the location of the front-end modules is expected at the lowest antiproton beam momentum and a luminosity of 1·1031 cm−2 s−1, leading to a predicted Mean Time Between Failures of 47 ± 10 hours per FPGA in the electromagnetic calorimeter.
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| 30. |
- Preston, Markus, et al.
(författare)
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Methodology for Multiparameter Evaluation of Barriers Against Proliferation of Minor Actinides
- 2024
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Ingår i: Nuclear Technology. - 0029-5450 .- 1943-7471.
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Tidskriftsartikel (refereegranskat)abstract
- There exist elements apart from uranium and plutonium that could potentially be used to construct the core of a nuclear explosive device. These belong to the so-called minor actinides (MAs), which exist in nonnegligible amounts in spent nuclear fuel (SNF) and are in nearly all cases not covered by international safeguards. Future reprocessing of SNF could result in significant separation of these elements, potentially leading to new proliferation concerns. In this work, a methodology for a transparent assessment of the barriers against proliferation of MAs has been developed and applied to the case of neptunium, americium, and curium separated from spent fuel from pressurized water reactors. In this methodology, openly available data and Monte Carlo simulations have been used to assess the barriers posed by a number of parameters relevant to the production of a nuclear explosive device from SNF. The evaluation shows that the properties of neptunium present low barriers to proliferation and that it should be discussed within the context of future nonproliferation treaties and possibly be placed under international safeguards. The properties of americium and curium present higher barriers to proliferation, meaning that these elements require less focus in the nonproliferation context.
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| 31. |
- Preston, Markus, 1989-, et al.
(författare)
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Neptunium: time for nuclear safeguards?
- 2022
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Plutonium and uranium are well known weapons-usable nuclear materials which are currently placed under international safeguards. Examples of nuclear-safeguards methods are surveillance of nuclear facilities, inspections of spent nuclear fuel and process monitoring at fuel reprocessing facilities. Once material comes under safeguards, records of the amount of material are kept throughout its life cycle, and material accountancy verification is regularly performed. Deviations from the expected material balances could indicate diversion of nuclear material.It has been known for many years that there exist materials which are currently not under full international safeguards, but which could at least theoretically be used to manufacture a nuclear explosive device. One material that has attracted particular attention in this context is neptunium, which can be found in spent nuclear fuel. Although it is unclear if neptunium has ever been used in a nuclear explosive device, measures for preventing un-declared separation of neptunium have been implemented since 20 years by the International Atomic Energy Agency. However, it has never been placed under safeguards to the same extent as uranium and plutonium. In part, this decision was motivated by the relatively limited amount of neptunium available 20 years ago. Many things have happened in the nuclear industry since then, and there might be a need for re-visiting the issue. In this paper, the relationship between neptunium and international safeguards will be discussed in the context of recent trends in the nuclear energy sector and efforts to close the nuclear fuel cycle.
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| 32. |
- Preston, Markus, 1989-, et al.
(författare)
-
Overview of initial work on spent-fuel verification at MYRRHA
- 2022
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Ingår i: Symposium on International Safeguards. - : International Atomic Energy Agency.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The MYRRHA facility, which is under development at SCK CEN in Mol, Belgium, will be a multi-purpose research facility centred around an accelerator-driven reactor cooled by lead-bismuth eutectic. The MYRRHA core will contain MOX fuel with an initial plutonium content of 30%, and the lead-bismuth coolant will result in a fast neutron spectrum in the reactor. Due to reasons such as these, the radionuclide composition of spent fuel from MYRRHA can be considerably different from that of spent fuel from typical light water reactors. These differences will affect the choice of non-destructive verification techniques to safeguard the spent fuel. Further practical considerations, for example considering spent-fuel storage in lead-bismuth eutectic, will affect the choice of measurement technique. In a project led by Uppsala University, first studies of the requirements on gamma-ray and neutron measurements of spent fuel from MYRRHA have been performed using depletion calculations and Monte Carlo simulations. These studies have included i) an investigation into the radionuclide composition and gamma-ray and neutron emission in spent fuel from MYRRHA, ii) an analysis of the possibilities to discriminate between spent MYRRHA fuel and spent light-water reactor fuels using gamma-ray and neutron signatures and machine learning, iii) a feasibility study of using gamma-ray spectroscopic measurement for assaying a MYRRHA fuel assembly stored in lead-bismuth eutectic, and iv) a feasibility study of using neutron measurements under similar conditions. In the paper, new results connecting these studies will be summarised to highlight some important consequences for future safeguards verification at fast reactor systems.
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| 33. |
- Preston, Markus, 1989-, et al.
(författare)
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Possibilities for monitoring the composition of an iPWR core using ex-core neutron detectors
- 2023
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Ingår i: Proceedings of the INMM & ESARDA Joint Annual Meeting.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The possibility for wide-spread implementation of small modular reactors (SMRs) in the coming years comes with associated challenges for international nuclear safeguards: more effective and efficient use of safeguards resources will be needed and safeguards methodologies for monitoring SMRs may need to be developed. Of particular interest are methods for unattended monitoring, which could complement on-site inspections at facilities. One possibility for remote monitoring is using neutron detectors to determine the time-evolution of the core fissile composition. Although ex-core neutron detectors are commonly used in nuclear power plants to monitor the short-term behaviour of the core, this technique would be based on long-term monitoring over one or more operating cycles.In this work, we investigate the possibilities for using ex-core neutron detectors to monitor the long-term composition of a 160 MW th NuScale integral pressurised water reactor (iPWR) core. This core was chosen as a first case study, given the wide spectrum of SMR concepts. The considered iPWR module is housed in a pool of borated water, which significantly affects the neutron flux outside the reactor. Depletion calculations in Serpent2 have been performed for a 2D model of the core to determine the evolution of the fuel composition over a two-year operating cycle. Using variance reduction techniques, the thermal and fast neutron fluxes were determined at various distances into the water outside the iPWR module. Changes in the ex-core neutron flux and its relationship to the flux in the core with fuel depletion were studied. It was found that the relationship between the ex-core neutron flux and the flux in the core changes during depletion. Different possible sources to these changes were studied to investigate the validity of the proposed safeguards monitoring technique for an iPWR module housed in water.
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| 34. |
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| 35. |
- Preston, Markus, et al.
(författare)
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Proton- and Neutron-Induced Single-Event Upsets in FPGAs for the PANDA Experiment
- 2020
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Ingår i: IEEE Transactions on Nuclear Science. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 0018-9499 .- 1558-1578. ; 67:6, s. 1093-1106
-
Tidskriftsartikel (refereegranskat)abstract
- Single-event upsets (SEUs) affecting the configuration memory of a 28-nm field-programmable gate array (FPGA) have been studied through experiments and Monte Carlo modeling. This FPGA will be used in the front-end electronics of the electromagnetic calorimeter in PANDA (Antiproton Annihilation at Darmstadt), an upcoming hadron-physics experiment. Results from proton and neutron irradiations of the FPGA are presented and shown to be in agreement with previous experimental results. To estimate the mean time between SEUs during operation of PANDA, a Geant4-based Monte Carlo model of the phenomenon has been used. This model describes the energy deposition by particles in a silicon volume, the subsequent drift and diffusion of charges in the FPGA memory cell, and the eventual collection of charges in the sensitive regions of the cell. The values of the two free parameters of the model, the sensitive volume side $d = 87$ nm and the critical charge $Q_{\text {crit}} = 0.23$ fC, were determined by fitting the model to the experimental data. The results of the model agree well with both the proton and neutron data and are also shown to correctly predict the cross sections for upsets induced by other particles. The model-predicted energy dependence of the cross section for neutron-induced upsets has been used to estimate the rate of SEUs during initial operation of PANDA. At a luminosity of $1\cdot 10<^>{31}$ cm$<^>{-2}\,\,\text{s}<^>{-1}$ , the predicted mean time between upsets (MTBU) is between 120 and 170 h per FPGA, depending on the beam momentum.
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| 36. |
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| 37. |
- Preston, Markus, 1989-, et al.
(författare)
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Simulation study of gamma-ray spectroscopy on MYRRHA spent fuel located in lead–bismuth eutectic
- 2022
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 1034
-
Tidskriftsartikel (refereegranskat)abstract
- A concept model of a measurement station for gamma-ray spectroscopy for safeguards verification of spent fuel from the future MYRRHA facility has been developed using MCNP6.2. The measurement station consists of a collimator and a lanthanum bromide detector which are placed adjacent to a cylindrical container with the fuel assembly submerged in lead–bismuth eutectic for cooling. The total count rate as well as the peak-area uncertainties for several gamma-ray peaks have been studied for a number of measurement geometries to determine the optimal collimator dimensions and assess how the performance depends on the lead–bismuth container geometry. Finally, the contribution from each fuel pin in the assembly to the detected signal has been determined as a function of gamma-ray energy to determine if the inner parts of the fuel assembly can be assayed with gamma-ray measurements. The results show that the dimensions of the lead–bismuth container will have a considerable effect on both the total count rate and the peak-area uncertainties, but that gamma-ray spectroscopy could be used for verification of spent fuel from MYRRHA.
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| 38. |
- Preston, Markus
(författare)
-
Single event upsets: measurements and modelling of proton- and neutron-induced errors in a 28 nm SRAM-based FPGA
- 2018
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Single event upsets are radiation-induced errors affecting electronic devices, which can cause corruption of processed data. The electromagnetic calorimeter of the PANDA experiment — a hadron-physics experiment currently under development — will employ Xilinx Kintex-7 field-programmable gate arrays (FPGAs) in its readout electronics. During operation of the experiment, the FPGAs will be exposed to a high flux of radiation. Single-event upsets caused by protons and neutrons in the configuration memory of the FPGA have been studied through experiments and theoretical modelling. The device was irradiated with protons and neutrons of energies up to 184 MeV, and the corresponding single event upset cross sections were determined. In order to describe the energy-dependence of the cross sections, and to predict the error rates during operation of PANDA, a Monte Carlo model of energy-deposition mechanisms in silicon has been developed. The model predictions agree well with the experimental data for both protons and neutrons. Using the developed model, the mean time between failures due to neutrons during initial operation of PANDA is estimated to be 180 ± 40 hours per FPGA.
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| 39. |
- Schroeder, Jennifer R., et al.
(författare)
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Assessment of pioglitazone and proinflammatory cytokines during buprenorphine taper in patients with opioid use disorder
- 2018
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Ingår i: Psychopharmacology. - : SPRINGER. - 0033-3158 .- 1432-2072. ; 235:10, s. 2957-2966
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Tidskriftsartikel (refereegranskat)abstract
- Background Preliminary evidence suggested that the PPAR gamma agonist pioglitazone reduces opioid-withdrawal symptoms, possibly by inhibiting increases in proinflammatory cytokines. Methods A randomized, placebo-controlled clinical trial was conducted utilizing two different study designs (entirely outpatient, and a combination of inpatient and outpatient) to evaluate the safety and efficacy of pioglitazone as an adjunct medication for people with opioid physical dependence undergoing a buprenorphine taper. Participants were stabilized on buprenorphine/naloxone (sublingual, up to 16/4 mg/day), then randomized to receive oral pioglitazone (up to 45 mg/day) or placebo before, during, and after buprenorphine taper. Outcome measures included the Subjective Opiate Withdrawal Scale (SOWS) and Clinical Opiate Withdrawal Scale, use of rescue medications to alleviate opioid withdrawal symptoms, and opioid-positive urine specimens. Cerebrospinal fluid (CSF) and plasma were collected during the taper in a subset of participants for measurement of proinflammatory cytokines. Results The clinical trial was prematurely terminated due to slow enrollment; 40 participants per group were required for adequate statistical power to test study hypotheses. Twenty-four participants enrolled; 17 received at least one dose of study medication (6 pioglitazone, 11 placebo). SOWS scores were higher in the pioglitazone arm than in the placebo arm after adjusting for use of rescue medications; participants in the pioglitazone arm needed more rescue medications than the placebo arm during the post-taper phase. SOWS scores were positively correlated with monocyte chemoattractant protein-1 (MCP-1) in CSF (r = 0.70, p = 0.038) and plasma (r = 0.77, p = 0.015). Participants having higher levels of plasma MCP-1 reported higher SOWS, most notably after the buprenorphine taper ended. Conclusions Results from this study provide no evidence that pioglitazone reduces opioid withdrawal symptoms during buprenorphine taper. High correlations between MCP-1 and opioid withdrawal symptoms support a role of proinflammatory processes in opioid withdrawal.
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| 40. |
- Singh, B., et al.
(författare)
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Study of doubly strange systems using stored antiprotons
- 2016
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Ingår i: Nuclear Physics A. - : Elsevier. - 0375-9474 .- 1873-1554. ; 954, s. 323-340
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Tidskriftsartikel (refereegranskat)abstract
- Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the PANDA experiment at FAIR. For the first time, high resolution gamma-spectroscopy of doubly strange Lambda Lambda-hypernuclei will be performed, thus complementing measurements of ground state decays of Lambda Lambda-hypernuclei at J-PARC or possible decays of particle unstable hypernuclei in heavy ion reactions. High resolution spectroscopy of multistrange Xi(-) -atoms will be feasible and even the production of Omega(-) -atoms will be within reach. The latter might open the door to the vertical bar S vertical bar = 3 world in strangeness nuclear physics, by the study of the hadronic Omega(-) -nucleus interaction. For the first time it will be possible to study the behavior of Xi(+) in nuclear systems under well controlled conditions.
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| 41. |
- Singh, B., et al.
(författare)
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Technical design report for the (P)over-barANDA Barrel DIRC detector
- 2019
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Ingår i: Journal of Physics G. - : IOP PUBLISHING LTD. - 0954-3899 .- 1361-6471. ; 46:4
-
Tidskriftsartikel (refereegranskat)abstract
- The (P) over bar ANDA (anti-Proton ANnihiliation at DArmstadt) experiment will be one of the four flagship experiments at the new international accelerator complex FAIR (Facility for Antiproton and Ion Research) in Darmstadt, Germany. (P) over bar ANDA will address fundamental questions of hadron physics and quantum chromodynamics using high-intensity cooled antiproton beams with momenta between 1.5 and 15 GeV/c and a design luminosity of up to 2 x 10(32) cm(-2) S-1. Excellent particle identification (PID) is crucial to the success of the (P) over bar ANDA physics program. Hadronic PID in the barrel region of the target spectrometer will be performed by a fast and compact Cherenkov counter using the detection of internally reflected Cherenkov light (DIRC) technology. It is designed to cover the polar angle range from 22 degrees to 140 degrees and will provide at least 3 standard deviations (s.d.) pi/K separation up to 3.5 GeV/c, matching the expected upper limit of the final state kaon momentum distribution from simulation. This documents describes the technical design and the expected performance of the (P) over bar ANDA Barrel DIRC detector. The design is based on the successful BaBar DIRC with several key improvements. The performance and system cost were optimized in detailed detector simulations and validated with full system prototypes using particle beams at GSI and CERN. The final design meets or exceeds the PID goal of clean pi/K separation with at least 3 s.d. over the entire phase space of charged kaons in the Barrel DIRC.
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| 42. |
- Spagnolo, Primavera A., et al.
(författare)
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Striatal Dopamine Release in Response to Morphine: A [C-11]Raclopride Positron Emission Tomography Study in Healthy Men
- 2019
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Ingår i: Biological Psychiatry. - : ELSEVIER SCIENCE INC. - 0006-3223 .- 1873-2402. ; 86:5, s. 356-364
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Preclinical and human positron emission tomography studies have produced inconsistent results regarding the effects of opioids on mesolimbic dopamine (DA). Here, we quantify striatal DA release (measured by [C-11]raclopride displacement) in response to an intravenous infusion of morphine, and its relationship with morphine-induced subjective effects, in healthy, nondependent opioid-experienced participants. METHODS: Fifteen healthy male participants were initially included. Sessions were on separate days. On session 1, participants received intravenous morphine (10 mg/70 kg) in the clinic to ensure tolerability. Participants without adverse reactions (n = 10) then received intravenous morphine and placebo (saline) sessions, in counterbalanced order, while undergoing [C-11]raclopride positron emission tomography scans. Subjective and physiological responses were assessed. Region-of-interest and voxelwise image analyses were used to assess changes in [C-11]raclopride nondisplaceable binding potential. RESULTS: Morphine produced marked subjective and physiological effects and induced a significant decrease in [C-11]raclopride nondisplaceable binding potential, particularly in the nucleus accumbens and globus pallidus, where the change in [C-11]raclopride nondisplaceable binding potential was approximately 9%. However, the subjective effects of morphine did not show a simple pattern of correlation with DA release. CONCLUSIONS: This is, to our knowledge, the first study providing in vivo human evidence that DA transmission in the ventral striatum is affected by morphine. Further studies are required to fully delineate the DA contribution to the reinforcing effects of opioids.
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| 43. |
- Van Zuijlen, K., et al.
(författare)
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Bryophytes of Europe Traits (BET) dataset: a fundamental tool for bryological studies
- 2023
-
Ingår i: Journal of Vegetation Science. - 1100-9233 .- 1654-1103.
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Tidskriftsartikel (refereegranskat)abstract
- Bryophytes are a diverse group of organisms with unique properties, yet they are severelyunderrepresented in plant trait databases. Building on the recently published European Red List ofbryophytes and previous trait compilations, we present the Bryophytes of Europe Traits (BET) dataset,including biological traits such as those related to life history, growth habit, sexual and vegetativereproduction, ecological traits such as indicator values, substrate and habitat, and bioclimatic variablesbased on the species’ European range. The dataset includes values for 65 traits and 25 bioclimaticvariables, containing more than 135 000 trait values with a completeness of 82.7% on average. Thedataset will enable future studies in bryophyte biology, ecology and conservation and may help toanswer fundamental questions in bryology.
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