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Your search keyword '"Sundén Erik A."' showing total 4 results
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4 results on '"Sundén Erik A."'

1. Impact of the JET ITER-like wall on H-mode plasma fueling

Author

Wiesen, S., Andersson Sundén, Erik, Binda, Federico, Cecconello, Marco, Conroy, Sean, Dzysiuk, Nataliia, Ericsson, Göran, Eriksson, Jacob, Hellesen, Carl, Hjalmarsson, Anders, Possnert, Göran, Sjöstrand, Henrik, Skiba, Mateusz, Weiszflog, Matthias, and Zychor, I.

Subjects
H-mode, Fusion, plasma och rymdfysik, JET, ITER-like wall, integrated modelling, plasma-wall interaction, Fusion, Plasma and Space Physics, pedestal fuelling
Abstract

JET ITER-like wall (ILW) experiments show that the edge density evolution is strongly linked with the poloidal distribution of the ionization source. The fueling profile in the JET-ILW is more delocalized as compared to JET-C (JET with carbon-based plasma-facing components PFCs). Compared to JET-C the H-mode pedestal fueling cycle is dynamically influenced by a combination of plasma-wall interaction features, in particular: (1) edge-localized modes (ELMs) induced energetic particles are kinetically reflected on W divertor PFCs leading to distributed refueling away from the divertor depending on the divertor plasma configuration, (2) delayed molecular re-emission and outgassing of particles being trapped in W PFCs (bulk-W at the high field side and W-coated CFCs at the low field side) with different fuel content and (3) outgassing from Be co-deposits located on top of the high-field side baffle region shortly after the ELM. In view of the results of a set of well diagnosed series of JET-ILW type-I ELMy H-mode discharges with good statistics, the aforementioned effects are discussed in view of H-mode pedestal fueling capacity. The ongoing modelling activities with the focus on coupled core-edge plasma simulations and plasma-wall interaction are described and discussed also in view of possible code improvements required. For complete list of authors see http://dx.doi.org/10.1088/1741-4326/aa69dd

Published
2017

2. Energy balance in JET

Author

Matthews, G. F., Andersson Sundén, Erik, Asp, E., Binda, Federico, Cecconello, Marco, Conroy, Sean, Dzysiuk, Nataliia, Ericsson, Göran, Eriksson, Jacob, Hellesen, Carl, Hjalmarsson, Anders, Possnert, Göran, Sjöstrand, Henrik, Skiba, Mateusz, Weiszflog, Matthias, Zychor, I., and JET Contributors

Subjects
Physics, Nuclear and High Energy Physics, Jet (fluid), Materials Science (miscellaneous), Energy balance, Calorimetry, lcsh:TK9001-9401, 7. Clean energy, 01 natural sciences, 010305 fluids & plasmas, ILW, Nuclear physics, Subatomär fysik, Nuclear Energy and Engineering, JET, visual_art, 0103 physical sciences, Subatomic Physics, visual_art.visual_art_medium, lcsh:Nuclear engineering. Atomic power, Tile, 010306 general physics, Energy (signal processing)
Abstract

In this paper we discuss results from the study of the energy balance in JET based on calculated heating energies, radiated energy from bolometry and tile calorimetry. Recent data enables us to be more confident in the numbers used and to exclude certain possibilities but the overall energy imbalance which typically amounts to 25% of total input remains unexplained. This shows that caution is required in interpreting fractional radiated powers which are commonly used to measure the effectiveness of impurity seeded scenarios at reducing divertor heat load. For complete list of authors see http://dx.doi.org/10.1016/j.nme.2016.12.012

Published
2017

3. Kinematic background discrimination methods using a fully digital data acquisition system for TOFOR.

Author

Skiba, Mateusz, Ericsson, Göran, Hjalmarsson, Anders, Hellesen, Carl, Conroy, Sean, Andersson-Sundén, Erik, Eriksson, Jacob, and JET Contributors, null

Subjects
*DATA transmission systems, *TIME-of-flight mass spectrometers, *FUSION reactors, *SCINTILLATORS, *DIGITIZATION
Abstract

A fully digital, prototype data acquisition system upgrade for the TOFOR neutron time-of-flight neutron spectrometer at the JET experimental fusion reactor in Culham, England, has been constructed. This upgrade, TOFu (Time-of-Flight upgrade), enables digitization of associated time and energy deposition information from the TOFOR scintillator detectors, facilitating discrimination of spectral background due to unrelated neutron events based on kinematic considerations. In this publication, a kinematic background discrimination method is presented using synthetic data and validated with experimental results. It is found that an improvement in signal-to-background ratio of 500% in certain spectral regions is possible with the new DAQ system. [ABSTRACT FROM AUTHOR]

Published
2016
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4. A prototype fully digital data acquisition system upgrade for the TOFOR neutron spectrometer at JET.

Author

Skiba, Mateusz, Ericsson, Göran, Hjalmarsson, Anders, Hellesen, Carl, Conroy, Sean, Andersson-Sundén, Erik, Eriksson, Jacob, and JET Contributors, null

Subjects
*DATA acquisition systems, *NEUTRON spectrometers, *JETS (Nuclear physics), *NEUTRON spectroscopy, *TIME-of-flight spectroscopy
Abstract

A prototype of a fully digital data acquisition system upgrade for the TOFOR time-of-flight fusion neutron spectrometer at JET has been implemented and evaluated. The core of the system is composed of five fast PXIe waveform digitisers (1 GSPS, 12 bits) with large internal fast memory (1 GB). Due to the complexity and high requirements on timing precision of the spectrometer, the design and implementation of such a system poses numerous technical challenges, in particular regarding time alignment and synchronisation of signal paths and digitiser modules. These issues and their solutions, as pertaining to the TOFOR spectrometer, are presented in detail in the present paper. As a final assessment of the ability of the new data acquisition system to reproduce the capabilities of the original TOFOR system, a thorough comparison of results produced using both systems is presented. The comparison with TOFOR has been performed with satisfying results. Two immediate advantages of the new data acquisition system are significantly improved triggering dead time (from about 70 ns to 10 ns) and the ability to adjust the triggering thresholds as needed during the analysis step. The enhanced spectroscopic capabilities of the new data acquisition system will be reported on in future publications. [ABSTRACT FROM AUTHOR]

Published
2016
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