14 MeV calibration of JET neutron detectors-phase 1: Calibration and characterization of the neutron source
Journal article, 2018
In view of the planned DT operations at JET, a calibration of the JET neutron monitors at 14 MeV neutron energy is needed using a 14 MeV neutron generator deployed inside the vacuum vessel by the JET remote handling system. The target accuracy of this calibration is 10% as also required by ITER, where a precise neutron yield measurement is important, e.g. for tritium accountancy. To achieve this accuracy, the 14 MeV neutron generator selected as the calibration source has been fully characterised and calibrated prior to the in-vessel calibration of the JET monitors. This paper describes the measurements performed using different types of neutron detectors, spectrometers, calibrated long counters and activation foils which allowed us to obtain the neutron emission rate and the anisotropy of the neutron generator, i.e.The neutron flux and energy spectrum dependence on emission angle, and to derive the absolute emission rate in 4π sr. The use of high resolution diamond spectrometers made it possible to resolve the complex features of the neutron energy spectra resulting from the mixed D/T beam ions reacting with the D/T nuclei present in the neutron generator target. As the neutron generator is not a stable neutron source, several monitoring detectors were attached to it by means of an ad hoc mechanical structure to continuously monitor the neutron emission rate during the in-vessel calibration. These monitoring detectors, two diamond diodes and activation foils, have been calibrated in terms of neutrons/counts within ± 5% total uncertainty. A neutron source routine has been developed, able to produce the neutron spectra resulting from all possible reactions occurring with the D/T ions in the beam impinging on the Ti D/T target. The neutron energy spectra calculated by combining the source routine with a MCNP model of the neutron generator have been validated by the measurements. These numerical tools will be key in analysing the results from the in-vessel calibration and to derive the response of the JET neutron detectors to DT plasma neutrons starting from the response to the generator neutrons, and taking into account all the calibration circumstances.
Neutron generator
Neutron calibration
Fusion reactor
Author
X. Litaudon
Culham Science Centre
S. Abduallev
Forschungszentrum Jülich
M. Abhangi
Institute for Plasma Research India
P. Abreu
Instituto Superior Tecnico
M. Afzal
Culham Science Centre
K.M. Aggarwal
Queen's University Belfast
T. Ahlgren
University of Helsinki
J. H. Ahn
The French Alternative Energies and Atomic Energy Commission (CEA)
L. Aho-Mantila
Technical Research Centre of Finland (VTT)
N. Aiba
National Institutes for Quantum and Radiological Science and Technology
M. Airila
Technical Research Centre of Finland (VTT)
R. Albanese
University of Naples Federico II
V. Aldred
Culham Science Centre
D. Alegre
Universidad Nacional de Educación a Distancia
E. Alessi
Istituto Di Fisica Del Plasma Piero Caldirola, Milan
P B Aleynikov
ITER Organization
A. Alfier
Consorzio Rfx
A. Alkseev
National Research Centre "Kurchatov Institute"
M. Allinson
Culham Science Centre
B Alper
Culham Science Centre
E. Alves
Instituto Superior Tecnico
G. Ambrosino
University of Naples Federico II
R. Ambrosino
University Parthenope
L. Amicucci
ENEA
V. Amosov
Troitsk Institute for Innovation and Fusion Research
E. Andersson Sundén
Uppsala University
M. Angelone
ENEA
M. Anghel
National Research and Development Institute for Cryogenics and Isotopic Technologies
C. Angioni
Max Planck Society
L. Appel
Culham Science Centre
C. Appelbee
Culham Science Centre
P. Arena
University of Catania
M. Ariola
University Parthenope
D. Alegre
The French Alternative Energies and Atomic Energy Commission (CEA)
S. Arshad
Fusion for Energy Joint Undertaking
A. Ash
Culham Science Centre
N. Ashikawa
National Institutes of Natural Sciences
V. Aslanyan
Massachusetts Institute of Technology (MIT)
O. Asunta
Aalto University
F. Auriemma
Consorzio Rfx
Y. Austin
Culham Science Centre
L. Avotina
University of Latvia
M.D. Axton
Culham Science Centre
C. Ayres
Culham Science Centre
M. Bacharis
Imperial College London
A. Baciero
Laboratorio Nacional de Fusion
D. Baião
Instituto Superior Tecnico
S. Bailey
Culham Science Centre
A. Baker
Culham Science Centre
I. Balboa
Culham Science Centre
M. Balden
Max Planck Society
N. Balshaw
Culham Science Centre
R. Bament
Culham Science Centre
J.W. Banks
Culham Science Centre
Y.F. Baranov
Culham Science Centre
M.A. Barnard
Culham Science Centre
D. Barnes
Culham Science Centre
M. Barnes
University of Oxford
R. Barnsley
ITER Organization
A. Baron Wiechec
Culham Science Centre
L.B. Orte
EUROfusion Programme Management Unit
M. Baruzzo
Consorzio Rfx
V. Basiuk
The French Alternative Energies and Atomic Energy Commission (CEA)
M. Bassan
ITER Organization
R. Bastow
Culham Science Centre
A. Batista
Instituto Superior Tecnico
P. Batistoni
ENEA
R. Baughan
Culham Science Centre
B. Bauvir
ITER Organization
L. Baylor
Oak Ridge National Laboratory
B. Bazylev
Karlsruhe Institute of Technology (KIT)
J. Beal
University of York
P.S. Beaumont
Culham Science Centre
M. Beckers
Forschungszentrum Jülich
B. Beckett
Culham Science Centre
A. Becoulet
The French Alternative Energies and Atomic Energy Commission (CEA)
N. Bekris
Culham Science Centre
M. Beldishevski
Culham Science Centre
K. Bell
Culham Science Centre
F. Belli
ENEA
M. Bellinger
Culham Science Centre
Belonohy
Max Planck Society
N. Ben Ayed
Culham Science Centre
N.A. Benterman
Culham Science Centre
H. Bergsåker
Royal Institute of Technology (KTH)
J. Bernardo
Instituto Superior Tecnico
M. Bernert
Max Planck Society
M. Berry
Culham Science Centre
L. Bertalot
ITER Organization
C. Besliu
Culham Science Centre
M. N. A. Beurskens
Max Planck Society
B. Bieg
Maritime University of Szczecin
J. Bielecki
Polish Academy of Sciences
T. Biewer
Oak Ridge National Laboratory
M. Bigi
Consorzio Rfx
P. Bílková
Czech Academy of Sciences
F. Binda
Uppsala University
A. Bisoffi
University of Trento
J. P. S. Bizarro
Instituto Superior Tecnico
C. Björkas
University of Helsinki
Dimitriy Yadykin
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Jan Weiland
Chalmers, Physics
Nuclear Fusion
0029-5515 (ISSN) 1741-4326 (eISSN)
Vol. 58 2 026012Subject Categories
Accelerator Physics and Instrumentation
Subatomic Physics
Fusion, Plasma and Space Physics
DOI
10.1088/1741-4326/aa98f6