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Cecconello, Marco
Alternative names
Publications (10 of 437) Show all publications
Cecconello, M., Dolby, I. J., Sperduti, A., Rivero-Rodriguez, J., Ericsson, G., Fitzgerald, I., . . . Team, M.-U. A. (2023). First observations of confined fast ions in MAST Upgrade with an upgraded neutron camera. Plasma Physics and Controlled Fusion, 65(3), Article ID 035013.
Open this publication in new window or tab >>First observations of confined fast ions in MAST Upgrade with an upgraded neutron camera
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2023 (English)In: Plasma Physics and Controlled Fusion, ISSN 0741-3335, E-ISSN 1361-6587, Vol. 65, no 3, article id 035013Article in journal (Refereed) Published
Abstract [en]

Spherical tokamaks are key to the successful design of operating scenarios of future fusion reactors in the areas of divertor physics, neutral beam current drive and fast ion physics. MAST Upgrade, which has successfully concluded its first experimental campaign, was specifically designed to address the role of the radial gradient of the fast ion distribution in driving the excitation of magneto-hydrodynamic (MHD) instabilities, such as toroidal Alfven eigenmodes, fish-bones and long-lived mode, thanks to its two tangential neutral beam injection systems, one on the equatorial plane and one that is vertically shifted 65 cm above the equatorial plane. To study the fast ion dynamics in the presence of such instabilities, as well as of sawteeth and neo-classical tearing modes, several fast ion diagnostics were upgraded and new ones added. Among them, the MAST prototype neutron camera (NC) has been upgraded to six, equatorial sight-lines. The first observations of the confined fast ion behavior with the upgraded NC in a wide range of plasma scenarios characterized by on-axis and/or off-axis heating and different MHD instabilities are presented here. The observations presented in this study confirm previous results on MAST but with a higher level of detail and highlight new physics observations unique to the MAST Upgrade. The results presented here confirm the improved performance of the NC Upgrade, which thus becomes one of the key elements, in combination with the rich set of fast ion diagnostics available on the MAST Upgrade, for a more constrained modeling of the fast ion dynamics in fusion reactor relevant scenarios.

Place, publisher, year, edition, pages
Institute of Physics Publishing (IOPP)IOP Publishing, 2023
Keywords
MAST Upgrade, fast ions, neutron diagnostics
National Category
Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:uu:diva-498125 (URN)10.1088/1361-6587/acb50c (DOI)000928603100001 ()
Funder
Swedish Research Council, 2021-05485
Available from: 2023-03-13 Created: 2023-03-13 Last updated: 2024-01-15Bibliographically approved
Biel, W., Ariola, M., Bolshakova, I., Brunner, K. J., Cecconello, M., Duran, I., . . . Zohm, H. (2022). Development of a concept and basis for the DEMO diagnostic and control system. Fusion engineering and design, 179, Article ID 113122.
Open this publication in new window or tab >>Development of a concept and basis for the DEMO diagnostic and control system
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2022 (English)In: Fusion engineering and design, ISSN 0920-3796, E-ISSN 1873-7196, Vol. 179, article id 113122Article in journal (Refereed) Published
Abstract [en]

An initial concept for the plasma diagnostic and control (D&C) system has been developed as part of European studies towards the development of a demonstration tokamak fusion reactor (DEMO). The main objective is to develop a feasible, integrated concept design of the DEMO D&C system that can provide reliable plasma control and high performance (electricity output) over extended periods of operation. While the fusion power is maximized when operating near to the operational limits of the tokamak, the reliability of operation typically improves when choosing parameters significantly distant from these limits. In addition to these conflicting requirements, the D&C development has to cope with strong adverse effects acting on all in vessel components on DEMO (harsh neutron environment, particle fluxes, temperatures, electromagnetic forces, etc.). Moreover, space allocation and plasma access are constrained by the needs for first wall integrity and optimization of tritium breeding. Taking into account these boundary conditions, the main DEMO plasma control issues have been formulated, and a list of diagnostic systems and channels needed for plasma control has been developed, which were selected for their robustness and the required coverage of control issues. For a validation and refinement of this concept, simulation tools are being refined and applied for equilibrium, kinetic and mode control studies.

Place, publisher, year, edition, pages
ElsevierElsevier BV, 2022
Keywords
DEMO, Tokamak, Plasma diagnostics, Plasma control
National Category
Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:uu:diva-475193 (URN)10.1016/j.fusengdes.2022.113122 (DOI)000793698700005 ()
Available from: 2022-06-07 Created: 2022-06-07 Last updated: 2024-01-15Bibliographically approved
Podesta, M., Gorelenkova, M., Gorelenkov, N. N., White, R. B., Bonofiglo, P. J., Poli, F. M., . . . Vallar, M. (2022). Development of a reduced model for energetic particle transport by sawteeth in tokamaks. Plasma Physics and Controlled Fusion, 64(2), Article ID 025002.
Open this publication in new window or tab >>Development of a reduced model for energetic particle transport by sawteeth in tokamaks
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2022 (English)In: Plasma Physics and Controlled Fusion, ISSN 0741-3335, E-ISSN 1361-6587, Vol. 64, no 2, article id 025002Article in journal (Refereed) Published
Abstract [en]

The sawtooth instability is known for inducing transport and loss of energetic particles (EPs), and for generating seed magnetic islands that can trigger tearing modes. Both effects degrade the overall plasma performance. Several theories and numerical models have been previously developed to quantify the expected EP transport caused by sawteeth, with various degrees of sophistication to differentiate the response of EPs at different energies and on different orbits (e.g. passing vs. trapped), although the analysis is frequently limited to a single time slice during a tokamak discharge. This work describes the development and initial benchmark of a framework that enables a reduced model for EP transport by sawteeth retaining the full EP phase-space information. The model, implemented in the ORBIT hamiltonian particle-following code, can be used either as a standalone post-processor taking input data from codes such as TRANSP, or as a pre-processor to compute transport coefficients that can be fed back to TRANSP for time-dependent simulations including the effects of sawteeth on EPs. The advantage of the latter approach is that the evolution of the EP distribution can be simulated quantitatively for sawtoothing discharges, thus enabling a more accurate modeling of sources, sinks and overall transport properties of EP and thermal plasma species for comprehensive physics studies that require detailed information of the fast-ion distribution function and its evolution over time.

Place, publisher, year, edition, pages
IOP Publishing Ltd, 2022
Keywords
NSTX, spherical tokamak, sawtooth, fast ions, neutral beam heating, TRANSP, NUBEAM
National Category
Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:uu:diva-463539 (URN)10.1088/1361-6587/ac37fe (DOI)000732439000001 ()
Available from: 2022-01-14 Created: 2022-01-14 Last updated: 2022-01-14Bibliographically approved
Marcinkevicius, B., Eriksson, J., Hjalmarsson, A., Conroy, S. & Ericsson, G. (2022). Fuel ion ratio determination using the 14 MeV Tandem neutron spectrometer for JET DTE1 campaign discharges. Fusion engineering and design, 184, Article ID 113259.
Open this publication in new window or tab >>Fuel ion ratio determination using the 14 MeV Tandem neutron spectrometer for JET DTE1 campaign discharges
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2022 (English)In: Fusion engineering and design, ISSN 0920-3796, E-ISSN 1873-7196, Vol. 184, article id 113259Article in journal (Refereed) Published
Abstract [en]

This paper investigates the determination of the fuel ion ratio nT/ntot in fusion experiments using two different approaches. The methods are applied to plasma discharges from the deuterium-tritium campaign at the Joint European Torus (JET) in 1997. Multiple discharges have been analysed using data acquired with the Tandem (KM2) neutron spectrometer, using a new neutron spectrometer response function and improved line-of-sight information.The two different approaches were generally similar with the exception of the beam slowing down modelling, handled by two different particle transport codes, namely, TRANSP and PENCIL.The results show that nT/ntot can be determined using Tandem neutron spectrometer data; nT/ntot using both of the approaches are consistent and within the uncertainty for a range of studied discharges.The obtained results support previous studies on nT/ntot determination using neutron spectroscopy. In addition, we have shown that PENCIL can be used instead of TRANSP for a range of discharges which could simplify and speed up the estimation of nT/ntot. The possible limitations of the approach using PENCIL could be investigated using different neutron spectrometer data from the 2021 JET deuterium-tritium campaign.A similar spectrometer like Tandem is planned to be operational at ITER and the results of this paper form the first experimental verification of the capability for nT/ntot measurements with such spectrometers. Further research on this could lead to better understanding of these instruments and their limitations before the start of experiments at ITER.

Place, publisher, year, edition, pages
Elsevier, 2022
Keywords
Neutron spectrometer, Hot plasma, JET, Tokamak, Fuel ion ratio
National Category
Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:uu:diva-487891 (URN)10.1016/j.fusengdes.2022.113259 (DOI)000869406200006 ()
Note

JET (Joint European Torus) medarbetare står som gruppförfattare i artikeln.

Här har de affilierade vid Uppsala Universitet tagits med.

Available from: 2022-11-08 Created: 2022-11-08 Last updated: 2022-11-08Bibliographically approved
Mailloux, J., Andersson Sundén, E., Cecconello, M., Conroy, S., Ericsson, G., Eriksson, B., . . . Zychor, I. (2022). Overview of JET results for optimising ITER operation. Nuclear Fusion, 62(4), Article ID 042026.
Open this publication in new window or tab >>Overview of JET results for optimising ITER operation
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2022 (English)In: Nuclear Fusion, ISSN 0029-5515, E-ISSN 1741-4326, Vol. 62, no 4, article id 042026Article in journal (Refereed) Published
Abstract [en]

The JET 2019–2020 scientific and technological programme exploited the results of years of concerted scientific and engineering work, including the ITER-like wall (ILW: Be wall and W divertor) installed in 2010, improved diagnostic capabilities now fully available, a major neutral beam injection upgrade providing record power in 2019–2020, and tested the technical and procedural preparation for safe operation with tritium. Research along three complementary axes yielded a wealth of new results. Firstly, the JET plasma programme delivered scenarios suitable for high fusion power and alpha particle (α) physics in the coming D–T campaign (DTE2), with record sustained neutron rates, as well as plasmas for clarifying the impact of isotope mass on plasma core, edge and plasma-wall interactions, and for ITER pre-fusion power operation. The efficacy of the newly installed shattered pellet injector for mitigating disruption forces and runaway electrons was demonstrated. Secondly, research on the consequences of long-term exposure to JET-ILW plasma was completed, with emphasis on wall damage and fuel retention, and with analyses of wall materials and dust particles that will help validate assumptions and codes for design and operation of ITER and DEMO. Thirdly, the nuclear technology programme aiming to deliver maximum technological return from operations in D, T and D–T benefited from the highest D–D neutron yield in years, securing results for validating radiation transport and activation codes, and nuclear data for ITER.

Place, publisher, year, edition, pages
Institute of Physics Publishing (IOPP), 2022
Keywords
overview, D-T preparation, tritium operations, plasma facing components (PFC), nuclear technology, JET with ITER-like wall, isotope
National Category
Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:uu:diva-482515 (URN)10.1088/1741-4326/ac47b4 (DOI)000829648300001 ()
Funder
European Commission, 633053
Note

For complete list of authors see http://dx.doi.org/10.1088/1741-4326/ac47b4

Available from: 2022-08-25 Created: 2022-08-25 Last updated: 2022-09-30Bibliographically approved
Giacomelli, L., Nocente, M., Cippo, E. P., Rebai, M., Rigamonti, D., Tardocchi, M., . . . Biel, W. (2022). Overview on the progress of the conceptual studies of a gamma ray spectrometer instrument for DEMO. Paper presented at International Conference on Fusion Reactor Diagnostics, SEP 07-11, 2020, Varenna, ITALY. Journal of Instrumentation, 17(8), Article ID C08020.
Open this publication in new window or tab >>Overview on the progress of the conceptual studies of a gamma ray spectrometer instrument for DEMO
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2022 (English)In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 17, no 8, article id C08020Article in journal (Refereed) Published
Abstract [en]

The future DEMO tokamak will be equipped with a suite of diagnostics which will operate as sensors to monitor and control the position and operation parameters of DT plasmas. Among the suite of sensors, an integrated neutron and gamma-ray diagnostic system is also studied to verify its capability and performance in detecting possible DEMO plasma position variations and contribute to the feedback system in maintaining DEMO DT plasma in stable conditions. This work describes the progress of the conceptual study of the gamma-ray diagnostic for DEMO reactor performed during the first Work-Package contract 2015-2020. The reaction of interest for this Gamma-Ray Spectrometer Instrument (GRSI) consists of D(T, gamma)He-5 with the emission of 16.63 MeV gamma rays. Due to DEMO tokamak design constraints, the gamma and neutron diagnostics are integrated, both featuring multi-line of sight (camera type), viewing DEMO plasma radially with vertical (12) and horizontal (13) viewing lines to diagnose the. and neutron emission from the DT plasma poloidal section. The GRSI design is based on the investigation of the reaction cross sections, on the calculations performed with GENESIS and MCNP simulation codes and on the physics and geometry constrains of the integrated instrument. GRSI features long collimators which diameters are constrained by the neutron flux at the neutron detectors of the Radial Neutron Camera (RNC) system placed in front, which are key to control DEMO DT plasma position. For these reasons, only few GRSI parameters can be independently selected to optimize its performance. Among these, the choice of the collimator diameters at the back side of the neutron detector box up to the GRSI detector, the use of LiH neutron attenuators in front of the GRSI detectors, the GRSI detector material and shielding. The GRSI detector is based on commercial LaBr3(Ce) inorganic scintillating crystal coupled with a photomultiplier tube or a silicon photomultiplier. They are designed to operate at high count rate although GRSI geometry constraints severely impact on this feature. The GRSI can also provide an independent assessment of DEMO DT fusion power and T burning.

Place, publisher, year, edition, pages
IOP Publishing Ltd, 2022
Keywords
Detector design and construction technologies and materials, Gamma camera, SPECT, PET PET/CT, coronary CT angiography (CTA), Nuclear instruments and methods for hot plasma diagnostics, Pulsed power
National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-501981 (URN)10.1088/1748-0221/17/08/C08020 (DOI)000969780400007 ()
Conference
International Conference on Fusion Reactor Diagnostics, SEP 07-11, 2020, Varenna, ITALY
Available from: 2023-05-22 Created: 2023-05-22 Last updated: 2023-05-22Bibliographically approved
Esposito, B., Marocco, D., Gandolfo, G., Belli, F., Bertalot, L., Blocki, J., . . . Zimbal, A. (2022). Progress of Design and Development for the ITER Radial Neutron Camera. Journal of fusion energy, 41(2), Article ID 22.
Open this publication in new window or tab >>Progress of Design and Development for the ITER Radial Neutron Camera
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2022 (English)In: Journal of fusion energy, ISSN 0164-0313, E-ISSN 1572-9591, Vol. 41, no 2, article id 22Article in journal (Refereed) Published
Abstract [en]

The paper presents an overview of the design status of the Radial Neutron Camera (RNC), that, together with the Vertical Neutron Camera, will provide, through reconstruction techniques applied to the measured line-integrated neutron fluxes, the time resolved measurement of the ITER neutron and alpha-source profile (i.e. neutron emissivity, neutrons emitted per unit time and volume). The RNC is composed of two subsystems, the In-Port RNC and Ex-Port RNC located, respectively, inside and outside the Plug of Equatorial Port #01. The In-Port subsystem is in a more advanced design stage since it has recently undergone the Final Design Review in the ITER procurement process. The paper describes the diagnostic layout, the interfaces, the measurement capabilities and the main challenges in its realization. Prototyping and testing of neutron detectors and electronics components were carried out and led to the choice of the component solutions that can match the environmental and operational constraints in terms radiation hardness, high temperature and electromagnetic compatibility. The performance of the RNC in terms of neutron emissivity measurement capability was assessed through 1D and 2D reconstruction analysis. It is proven that the neutron emissivity can be reconstructed in real-time within the measurement requirements: 10% accuracy, 10 ms time resolution and a/10 (a = plasma minor radius) space resolution.

Place, publisher, year, edition, pages
Springer, 2022
Keywords
Neutron detector, Neutron camera, Tomography, ITER
National Category
Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:uu:diva-486048 (URN)10.1007/s10894-022-00333-9 (DOI)000856510900001 ()
Funder
EU, Horizon 2020EU, Horizon 2020
Available from: 2022-10-14 Created: 2022-10-14 Last updated: 2022-10-14Bibliographically approved
Spizzo, G., Gobbin, M., Agostinetti, P., Albanese, R., Ambrosino, R., Casiraghi, I., . . . Zonca, F. (2021). Collisionless losses of fast ions in the divertor tokamak test due to toroidal field ripple. Nuclear Fusion, 61(11), Article ID 116016.
Open this publication in new window or tab >>Collisionless losses of fast ions in the divertor tokamak test due to toroidal field ripple
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2021 (English)In: Nuclear Fusion, ISSN 0029-5515, E-ISSN 1741-4326, Vol. 61, no 11, article id 116016Article in journal (Refereed) Published
Abstract [en]

In this paper we analyze fast ion motion in the divertor tokamak test (DTT) device (Albanese et al 2017 Nucl. Fusion 57 016010). It is planned that DTT will be heated through a mix of 45 MW heating power, including 15 MW negative-ion-based neutral beam heating (NNBI) which is currently being developed by Consorzio RFX in Padova, Italy (Agostinetti et al 2019 Fusion Eng. Design 146 441-446). An issue for DTT is that a toroidal field (TF) ripple with a maximum value of about similar to 0.42% (with respect to the on-axis magnetic field B (0)) is expected on the low-field side, and this ripple interacts with fast ions through the rather well-known phenomena of ripple-precession resonances, in addition to prompt losses of ions which do not complete a full orbit in the poloidal plane. We will show that, with the planned geometry of NNBI, prompt losses are negligible, and ripple-precession losses amount to a maximum of 0.15%. The calculations are performed with the guiding center code Orbit using two different equilibria, and a beam with an energy of 400 keV and the injection angle alpha (inj) = 40 degrees (measured w.r.t. the first wall), which corresponds to a pitch of injected particles lambda = v (parallel to)/v approximate to sin alpha (inj) = 0.65. The main resonances are of the form omega (b) - nN omega (d) = 0, omega (b) and omega (d) being the bounce and precession frequency, respectively, N = 18 the ripple periodicity and 3 <= n <= 6 are the toroidal wavenumbers of the resonances. Although collisionless interaction with the TF ripple does not pose a serious threat to the NNBI project, an open question remains as to whether the presence of these resonances will interact with fast particles accelerated by Alfven eigenmodes, and if stochastization of the resonances is possible in DTT, as was observed in the past in TORE SUPRA.

Place, publisher, year, edition, pages
Institute of Physics Publishing (IOPP)IOP Publishing, 2021
Keywords
tokamak, energetic particles, neutral beam injection, Hamiltonian dynamics, resonances, toroidal field ripple, wave-particle interaction
National Category
Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:uu:diva-458327 (URN)10.1088/1741-4326/ac1e08 (DOI)000705944300001 ()
Funder
EU, Horizon 2020, 633053EU, Horizon 2020, WP19-ER/ENEA-05
Available from: 2021-11-09 Created: 2021-11-09 Last updated: 2024-01-15Bibliographically approved
Cecconello, M., Conroy, S., Ericsson, G., Eriksson, J., Hjalmarsson, A., Sperduti, A., . . . Villari, R. (2021). Conceptual design of a collimated neutron flux monitor and spectrometer for DTT. Fusion engineering and design, 167, Article ID 112382.
Open this publication in new window or tab >>Conceptual design of a collimated neutron flux monitor and spectrometer for DTT
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2021 (English)In: Fusion engineering and design, ISSN 0920-3796, E-ISSN 1873-7196, Vol. 167, article id 112382Article in journal (Refereed) Published
Abstract [en]

A conceptual design and performance studies for a collimated neutron flux monitor and neutron spectrometer for the Divertor Tokamak Test (DTT) facility are presented. This study is based on the single-null divertor configuration and for “Half Power” and “Full power” scenarios with 15 MW of negative-ion NBI, 29 MW of ECH and 3 MW of ICRF heating with a maximum neutron yield of 1.5 × 1017 s−1. Fast ion distributions (both from auxiliary heating systems and fusion born) have been simulated in TRANSP/NUBEAM and the corresponding neutron energy spectra have been calculated using DRESS. Synthetic diagnostics have been implemented to determine the neutron fluxes and spectra at the detector location. Neutron emissivity profiles, plasma position, core ion temperature and the ratio of thermal and non-thermal D ion populations can be obtained with good accuracy and time resolution.

Place, publisher, year, edition, pages
Elsevier, 2021
Keywords
DTT, Radial neutron camera, Neutron spectrometer, Triton burnup, TRANSP/NUBEAM, DRESS
National Category
Fusion, Plasma and Space Physics
Research subject
Physics with specialization in Applied Nuclear Physics
Identifiers
urn:nbn:se:uu:diva-439961 (URN)10.1016/j.fusengdes.2021.112382 (DOI)000670071900003 ()
Funder
Swedish Research Council, 2015-03869European Commission, 633053
Available from: 2021-04-12 Created: 2021-04-12 Last updated: 2024-01-15Bibliographically approved
Sperduti, A., Cecconello, M., Conroy, S. & Snicker, A. (2021). Neutron rate estimates in MAST based on gyro-orbit modelling of fast ions. Nuclear Fusion, 61(1), Article ID 016028.
Open this publication in new window or tab >>Neutron rate estimates in MAST based on gyro-orbit modelling of fast ions
2021 (English)In: Nuclear Fusion, ISSN 0029-5515, E-ISSN 1741-4326, Vol. 61, no 1, article id 016028Article in journal (Refereed) Published
Abstract [en]

A discrepancy between predicted and measured neutron rates on MAST using TRANSP/NUBEAM has previously been observed and a correction factor of about 0.6 was needed to match the two: this correction factor could not be accounted for by the experimental uncertainties in the plasma kinetic profiles nor in the NBI energy and power (Cecconello et al 2019 Nucl. Fusion 59 016006). Further causes of this discrepancy are here studied by means of TRANSP/NUBEAM and ASCOT/BBNBI simulations. Different equilibria, toroidal field ripples, uncertainties on the NBI divergence value and gyro-orbit effects were studied and simulations were performed with both transport codes. It was found that the first three effects accounted for only a 5% variation in the fast ion density. On the other hand, full gyro-orbit simulations of the fast ions dynamics carried out in ASCOT/BBNBI resulted in an approximately 20% reduction of the fast ion population compared to TRANSP/NUBEAM. A detailed analysis of the fast ion distributions showed how the drop occurred regardless of the energy at pitch values <=-0.4. The DRESS code was then used to calculate the neutron rate at the neutron camera detector's location showing that the discrepancy is considerably reduced when the full gyro-orbit fast ion distribution is used, with now the correction factor, used to match experimental and predicted neutron rates, being around 0.9.

Place, publisher, year, edition, pages
Institute of Physics Publishing (IOPP)IOP Publishing, 2021
Keywords
MAST, TRANSP, NUBEAM, ASCOT, BBNBI, fusion product deficit, fast ions
National Category
Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:uu:diva-430580 (URN)10.1088/1741-4326/abc433 (DOI)000598697000001 ()
Funder
EU, Horizon 2020, 633053Swedish Research CouncilAcademy of Finland, 324759
Available from: 2021-01-14 Created: 2021-01-14 Last updated: 2024-01-15Bibliographically approved
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