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Kallne, Jan
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Publications (10 of 84) Show all publications
Nocente, M., Källne, J., Salewski, M., Tardocchi, M. & Gorini, G. (2015). Gamma-ray emission spectrum from thermonuclear fusion reactions without intrinsic broadening. Nuclear Fusion, 55(12), Article ID 123009.
Open this publication in new window or tab >>Gamma-ray emission spectrum from thermonuclear fusion reactions without intrinsic broadening
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2015 (English)In: Nuclear Fusion, ISSN 0029-5515, E-ISSN 1741-4326, Vol. 55, no 12, article id 123009Article in journal (Refereed) Published
Abstract [en]

First principle calculations of the gamma-ray energy spectrum arising from thermonuclear reactions without intrinsic broadening in fusion plasmas are presented, extending the theoretical framework needed to interpret measurements up to the accuracy level enabled by modern high resolution instruments. An analytical formula for the spectrum from Maxwellian plasmas, which extends to higher temperatures than the results previously available in the literature, has been derived and used to discuss the assumptions and limitations of earlier models. In case of radio-frequency injection, numerical results based on a Monte Carlo method are provided, focusing in particular on improved relations between the peak shift and width from the d(p, gamma)He-3 reaction and the temperature of protons accelerated by radio-frequency heating.

The results presented in this paper significantly improve the accuracy of diagnostic information that can be extracted from the gamma-ray emission spectrum of fusion reactions without intrinsic broadening and are of relevance for applications to high performance plasmas of present and next generation devices.

National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-268860 (URN)10.1088/0029-5515/55/12/123009 (DOI)000366534500011 ()
Available from: 2015-12-10 Created: 2015-12-10 Last updated: 2017-12-01Bibliographically approved
Zhang, X., Chen, Z., Peng, X., Hu, Z., Du, T., Cui, Z., . . . Chen, J. (2014). Diagnosing NB plasmas on the EAST tokamak with new time-of-flight neutron spectrometer. Paper presented at 13th IAEA Technical Meeting on Energetic Particles in Magnetic Confinement Systems, SEP 17-20, 2013, Beijing, PEOPLES R CHINA. Nuclear Fusion, 54(10), 104008
Open this publication in new window or tab >>Diagnosing NB plasmas on the EAST tokamak with new time-of-flight neutron spectrometer
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2014 (English)In: Nuclear Fusion, ISSN 0029-5515, E-ISSN 1741-4326, Vol. 54, no 10, p. 104008-Article in journal, Meeting abstract (Refereed) Published
Abstract [en]

The new neutron spectrometer time-of-flight enhanced diagnostics (TOFED) for the EAST tokamak is presented and its characteristics are described in terms of simulation results, as well as the interface in the torus hall along with new neutral beam (NB) injectors. The use of TOFED for studies of the slowing down of NB-injected deuterons is illustrated. The implications of measuring the neutron emission on a long pulse machine are discussed together with the experimental challenges and diagnostic possibilities approaching those to be encountered in continuous operation.

Keywords
neutron spectrometer, time-of-flight technique, neutral beam plasmas, EAST
National Category
Physical Sciences Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-240021 (URN)10.1088/0029-5515/54/10/104008 (DOI)000344964200017 ()
Conference
13th IAEA Technical Meeting on Energetic Particles in Magnetic Confinement Systems, SEP 17-20, 2013, Beijing, PEOPLES R CHINA
Available from: 2015-01-05 Created: 2015-01-05 Last updated: 2017-12-05Bibliographically approved
Nocente, M., Albergante, M., Eriksson, J., Conroy, S., Ericsson, G., Farina, D., . . . Gorini, G. (2014). Neutron spectroscopy measurements of tritium beam transport at JET. Paper presented at 13th IAEA Technical Meeting on Energetic Particles in Magnetic Confinement Systems, Sep 17-20, 2013, Beijing, China. Nuclear Fusion, 54(10), 104010
Open this publication in new window or tab >>Neutron spectroscopy measurements of tritium beam transport at JET
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2014 (English)In: Nuclear Fusion, ISSN 0029-5515, E-ISSN 1741-4326, Vol. 54, no 10, p. 104010-Article in journal, Meeting abstract (Refereed) Published
Abstract [en]

A detailed description of the 14 MeV neutron emission in plasmas heated by neutral beam injection has been carried out by coupling Monte Carlo calculations of the neutron emission spectrum with TRANSP modelling of the beam ion energy distributions. The model is used to study tritium beam injection experiments of the JET trace tritium campaign for internal transport barrier (ITB) and H-mode discharges. For ITB discharges, the measured neutron emission spectrum is well described by modelling using as input the beam ion distribution calculated with TRANSP. For H mode discharges the neutron spectrum can be reproduced only if high energy tritons are lost from the plasma, suggesting the possible role of low frequency tearing modes on the beam ions. The presented results are of relevance for tritium beam transport studies in trace tritium experiments and, more generally, for deuterium and tritium transport studies in high power experiments using neutron emission spectroscopy.

National Category
Fusion, Plasma and Space Physics Engineering and Technology
Research subject
Engineering Science with specialization in Science of Electricity
Identifiers
urn:nbn:se:uu:diva-233736 (URN)10.1088/0029-5515/54/10/104010 (DOI)000344964200019 ()
Conference
13th IAEA Technical Meeting on Energetic Particles in Magnetic Confinement Systems, Sep 17-20, 2013, Beijing, China
Available from: 2014-10-09 Created: 2014-10-09 Last updated: 2018-04-23Bibliographically approved
Moiseenko, V. E., Kotenko, V. G., Chernitskiy, S. V., Nemov, V. V., Ågren, O., Noack, K., . . . Garkusha, I. E. (2014). Research on stellarator-mirror fission-fusion hybrid. Plasma Physics and Controlled Fusion, 56(9), 094008
Open this publication in new window or tab >>Research on stellarator-mirror fission-fusion hybrid
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2014 (English)In: Plasma Physics and Controlled Fusion, ISSN 0741-3335, E-ISSN 1361-6587, Vol. 56, no 9, p. 094008-Article in journal (Refereed) Published
Abstract [en]

The development of a stellarator-mirror fission-fusion hybrid concept is reviewed. The hybrid comprises of a fusion neutron source and a powerful sub-critical fast fission reactor core. The aim is the transmutation of spent nuclear fuel and safe fission energy production. In its fusion part, neutrons are generated in deuterium-tritium (D-T) plasma, confined magnetically in a stellarator-type system with an embedded magnetic mirror. Based on kinetic calculations, the energy balance for such a system is analyzed. Neutron calculations have been performed with the MCNPX code, and the principal design of the reactor part is developed. Neutron outflux at different outer parts of the reactor is calculated. Numerical simulations have been performed on the structure of a magnetic field in a model of the stellarator-mirror device, and that is achieved by switching off one or two coils of toroidal field in the Uragan-2M torsatron. The calculations predict the existence of closed magnetic surfaces under certain conditions. The confinement of fast particles in such a magnetic trap is analyzed.

Keywords
fusion reactor, fission reactor, fusion-fission hybrid, stellarator, mirror
National Category
Physical Sciences Engineering and Technology
Research subject
Engineering Science with specialization in Science of Electricity
Identifiers
urn:nbn:se:uu:diva-234179 (URN)10.1088/0741-3335/56/9/094008 (DOI)000341854100009 ()
Available from: 2014-10-15 Created: 2014-10-14 Last updated: 2017-12-05Bibliographically approved
Zhang, X., Källne, J., Gorini, G., Nocente, M., Fan, T., Yuan, X., . . . Chen, Z. (2014). Second generation fusion neutron time-of-flight spectrometer at optimized rate for fully digital data acquisition. Review of Scientific Instruments, 85(4), 043503
Open this publication in new window or tab >>Second generation fusion neutron time-of-flight spectrometer at optimized rate for fully digital data acquisition
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2014 (English)In: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 85, no 4, p. 043503-Article in journal (Refereed) Published
Abstract [en]

The progress on high-rate event recording of data is taken as starting point to revisit the design of fusion neutron spectrometers based on the TOF (time-of-flight) technique. The study performed was aimed at how such instruments for optimized rate (TOFOR) can be further developed to enhance the plasma diagnostic capabilities based on measurement of the 2.5 MeV dd neutron emission from D plasmas, especially the weak spectral components that depend on discrimination of extraneous events. This paper describes a design (TOFOR II) adapted for use with digital wave form recording of all detector pulses providing information on both amplitude (pulse height) and timing. The results of simulations are presented and the performance enhancement is assessed in comparison to the present.

National Category
Accelerator Physics and Instrumentation Engineering and Technology
Research subject
Engineering Science with specialization in Science of Electricity
Identifiers
urn:nbn:se:uu:diva-227288 (URN)10.1063/1.4869804 (DOI)000335920600017 ()
Available from: 2014-06-25 Created: 2014-06-24 Last updated: 2017-12-05Bibliographically approved
Ågren, O., Moiseenko, V. E., Noack, K., Hagnestål, A., Källne, J. & Anglart, H. (2013). Hybrid Reactor Studies Based on the Straight Field Line Mirror. Paper presented at Joint Conference of 9th International Conference on Open Magnetic Systems for Plasma Confinement (OS) and 3rd International Workshop on Plasma Material Interaction Facilities for Fusion Research (PMIF), AUG 27-31, 2012, Tsukuba, JAPAN. Fusion science and technology, 63(1T), 52-57
Open this publication in new window or tab >>Hybrid Reactor Studies Based on the Straight Field Line Mirror
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2013 (English)In: Fusion science and technology, ISSN 1536-1055, E-ISSN 1943-7641, Vol. 63, no 1T, p. 52-57Article in journal (Refereed) Published
Abstract [en]

The straight field line mirror (SFLM) hybrid reactor studies aim to identify a concept where the safety of fission power production could be enhanced. A fusion neutron source could become a mean to achieve this. The SFLM studies address critical issues such as reactor safety, natural circulation of coolants, steady state operation for a year or more and means to avoid too strong material loads by a proper geometrical arrangement of the reactor components. A key result is that power production may be possible with a fusion Q factor as low as 0.15. This possibility arises from the high power amplification by fission, which within reactor safety margins may exceed a factor of 100. The requirements on electron temperature are dramatically lower for a fusion hybrid compared to a stand-alone fusion reactor. This and several other factors are important for our choice to select a mirror machine for the fusion hybrid reactor studies.

National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-224503 (URN)000333412900011 ()
Conference
Joint Conference of 9th International Conference on Open Magnetic Systems for Plasma Confinement (OS) and 3rd International Workshop on Plasma Material Interaction Facilities for Fusion Research (PMIF), AUG 27-31, 2012, Tsukuba, JAPAN
Available from: 2014-05-14 Created: 2014-05-13 Last updated: 2017-12-05Bibliographically approved
Nocente, M., Källne, J., Grosso, G., Tardocchi, M. & Gorini, G. (2013). Reaction analysis of neutron emission from D and DT plasmas with/without 3 He. Nuclear Fusion, 53(5), Article ID 053010.
Open this publication in new window or tab >>Reaction analysis of neutron emission from D and DT plasmas with/without 3 He
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2013 (English)In: Nuclear Fusion, ISSN 0029-5515, E-ISSN 1741-4326, Vol. 53, no 5, article id 053010Article in journal (Refereed) Published
Abstract [en]

The effects of nuclear elastic scattering (knock-on) from energetic light ions on the neutron emission spectrum in fusion plasmas are studied. The knock-on spectral features in D and DT plasmas without and with radio frequency heating on a 3 He minority component are determined through Monte Carlo simulations. The neutron production magnitudes are determined relative to those due to fuel ions in the thermal bulk state (down to the level of 10 −5 ), and the interference of higher order terms in the outlying spectral regions where these dominate is evaluated. The study completes the mapping of nuclear reaction and elastic scattering effects on the neutron emission spectrum including first-, second- and third-order processes. Included are the cross-couplings between dd and dt fusion reactions as manifested in the full neutron spectrum ( E n = 0–20 MeV) for DT plasmas of varying isotopic composition. This study determines the relationship between components of the neutron emission spectra and those of the underlying ion velocity distributions, which provides a general basis for judging the plasma diagnostic information that can potentially be extracted from measurement and analysis of such neutron data.

National Category
Natural Sciences Engineering and Technology
Research subject
Engineering Science with specialization in Science of Electricity
Identifiers
urn:nbn:se:uu:diva-213005 (URN)10.1088/0029-5515/53/5/053010 (DOI)000319404700010 ()
Available from: 2013-12-17 Created: 2013-12-17 Last updated: 2017-12-06Bibliographically approved
Ågren, O., Moiseenko, V., Noack, K., Hagnestål, A., Källne, J. & Anglart, H. (2012). Hybrid reactor studies based on the straight field line mirror: Invited talk. Paper presented at International Conference on Open Magnetic Systems for Plasma Confinement (OS, Tsukuba, Japan, August (2012).
Open this publication in new window or tab >>Hybrid reactor studies based on the straight field line mirror: Invited talk
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2012 (English)Conference paper, Published paper (Refereed)
National Category
Engineering and Technology
Research subject
Engineering Science with specialization in Science of Electricity
Identifiers
urn:nbn:se:uu:diva-190436 (URN)
Conference
International Conference on Open Magnetic Systems for Plasma Confinement (OS, Tsukuba, Japan, August (2012)
Available from: 2013-01-08 Created: 2013-01-08 Last updated: 2013-03-04
Källne, J., Noack, K., Ågren, O., Gorini, G., Tardocchic, M. & Grosso, G. (2012). Neutron Diagnostics For Mirror Hybrids. In: Jan Källne, Dimitri Ryutov, Giuseppe Gorini, Carlo Sozzi, Marco Tardocchi (Ed.), Fusion for Neutrons and Subcritical Nuclear Fission: Proceedings of the International Conference. Paper presented at International Workshop on Fusion Neutrons and Subcritical Nuclear Fission (FUNFI), SEP 12-15, 2011, Varenna, ITALY (pp. 281-288).
Open this publication in new window or tab >>Neutron Diagnostics For Mirror Hybrids
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2012 (English)In: Fusion for Neutrons and Subcritical Nuclear Fission: Proceedings of the International Conference / [ed] Jan Källne, Dimitri Ryutov, Giuseppe Gorini, Carlo Sozzi, Marco Tardocchi, 2012, p. 281-288Conference paper, Published paper (Refereed)
Abstract [en]

Fusion-fission (FuFi) hybrids will need instrumentation to diagnose the deuterium-tritium plasma, whose 14-MeV neutron emission is the driver of the sub-critical fission core. While the fission neutron yield rate (Y-fi and hence power P-fi) can be monitored with standard instrumentation, fusion plasmas in hybrids require special diagnostics where the determination of Y-th (proportional to P-fu) is a challenge. Information on Y-fu is essential for assessing the fusion plasma performance which together with Y-fi allows for the validation of the neutron multiplication factor (k) of the subcritical fission core. Diagnostics for hybrid plasmas are heuristically discussed with special reference to straight field line mirror (SFLM). Relevant DT plasma experience from JET and plans for ITER in the main line of fusion research were used as input. It is shown that essential SFLM plasma information can potentially be obtained with proposed instrumentation, but the state of the hybrid plasma must be predictably robust as derived from fully diagnosed dedicated experiments without interface restrictions of the hybrid application.

Series
AIP Conference Proceedings, ISSN 0094-243X ; 1442
Keywords
Diagnostics, Fusion-fission hybrids, Mirror plasmas, Neutron monitoring
National Category
Engineering and Technology
Research subject
Engineering Science with specialization in Science of Electricity
Identifiers
urn:nbn:se:uu:diva-181212 (URN)10.1063/1.4706881 (DOI)000306895100034 ()978-0-7354-1038-1 (ISBN)
Conference
International Workshop on Fusion Neutrons and Subcritical Nuclear Fission (FUNFI), SEP 12-15, 2011, Varenna, ITALY
Available from: 2012-09-24 Created: 2012-09-19 Last updated: 2013-03-04Bibliographically approved
Noack, K., Ågren, O., Källne, J., Hagnestål, A. & Moiseenko, V. E. (2012). Safety And Power Multiplication Aspects Of Mirror Fusion-Fission Hybrids. In: Jan Källne, Dimitri Ryutov, Giuseppe Gorini, Carlo Sozzi, Marco Tardocchi (Ed.), Fusion for Neutrons and Subcritical Nuclear Fission: Proceedings of the International Conference. Paper presented at International Workshop on Fusion Neutrons and Subcritical Nuclear Fission (FUNFI), SEP 12-15, 2011, Varenna, ITALY (pp. 186-198).
Open this publication in new window or tab >>Safety And Power Multiplication Aspects Of Mirror Fusion-Fission Hybrids
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2012 (English)In: Fusion for Neutrons and Subcritical Nuclear Fission: Proceedings of the International Conference / [ed] Jan Källne, Dimitri Ryutov, Giuseppe Gorini, Carlo Sozzi, Marco Tardocchi, 2012, p. 186-198Conference paper, Published paper (Refereed)
Abstract [en]

Recently, in a research project at Uppsala University a simplified neutronic model for a straight field line mirror hybrid has been devised and its most important operation parameters have been calculated under the constraints of a fission power production of 3 GW and that the effective multiplication factor k(eff) does not exceed 0.95. The model can be considered as representative for hybrids driven by other types of mirrors too. In order to reduce the demand on the fusion power of the mirror, a modified option of the hybrid has been considered that generates a reduced fission power of 1.5 GW with an increased maximal value k(eff) = 0.97. The present paper deals with nuclear safety aspects of this type of hybrids. It presents and discusses calculation results of reactivity effects as well as of driver effects.

Series
AIP Conference Proceedings, ISSN 0094-243X ; 1442
Keywords
Fusion-fission hybrid, Mirror plasma device, Spent nuclear fuel, Nuclear safety, MCNP5 calculations
National Category
Engineering and Technology
Research subject
Engineering Science with specialization in Science of Electricity
Identifiers
urn:nbn:se:uu:diva-181209 (URN)10.1063/1.4706868 (DOI)000306895100021 ()978-0-7354-1038-1 (ISBN)
Conference
International Workshop on Fusion Neutrons and Subcritical Nuclear Fission (FUNFI), SEP 12-15, 2011, Varenna, ITALY
Available from: 2012-09-24 Created: 2012-09-19 Last updated: 2016-04-21Bibliographically approved
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