Neutron Emission Profile And Neutron Spectrum Measurements At JET: Status And Plans

Journal Article · Wed Mar 12 00:00:00 EDT 2008 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2905080· OSTI ID:21136781

Popovichev, S; Kiptily, V; Syme, B ^[1]; Bertalot, L ^[2]; Belli, F; Esposito, B; Marocco, D; Riva, M ^[3]; Bonheure, G ^[4]; Conroy, S; Hjalmarsson, A; Ericsson, G; Kaellne, J; Weiszflog, M ^[5]; Murari, A ^[6]; Tsalas, M ^[7]

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1. EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon (United Kingdom)
2. ITER-JWS, Cadarache, 13108, St Paul lez Durance (France)
3. Associazione EURATOM/ENEA sulla Fusione, Frascati, Rome (Italy)
4. Association Euratom-Belgian state, Partners in the TEC, ERM-KMS, Brussels (Belgium)
5. INF, Uppsala University, EURATOM-VR Association, Uppsala (Sweden)
6. Consorzio RFX-Associazione EURATOM-ENEA per la Fusione, 1-35127 Padova (Italy)
7. Association EURATOM-Hellenic Republic, NCSR 'Demokritos', Agia Paraskevi Attica (Greece)

In large tokamak devices, such as JET, TFTR, JT-60U and ITER, a neutron emission profile monitor is considered as one of the principal diagnostic tools, firstly in providing information to characterize the fusion source in terms of its location, shape, intensity and secondly in developing an understanding of fast ion physics in tokamak plasmas. The JET neutron profile monitor is one of the most advanced such instruments currently operating. It enables 2-D imaging of the non-circular plasma neutron source through a tomographic deconvolution of line-integrated measurements. Historically it was usually assumed that the fusion neutron source is a function of the magnetic flux surfaces (MFS), but recent JET results have clearly demonstrated the influence of non-uniform fast particle populations on the neutron emission profile.Neutron energy spectroscopy also carries valuable information about fast ion behaviour and the fusion and nuclear reactions taking place in the plasma. Spectrum measurements of neutrons will be particularly important for the up-coming JET experiments with a Be wall. The neutron spectroscopy capabilities at JET were recently enhanced by several instruments: a new time-of-flight spectrometer optimized for high count rates (TOFOR), compact neutron spectrometers based on organic scintillator (NE213) and an upgrade of the Magnetic Proton Recoil system (MPRu). In recent JET campaigns, a prototype digital pulse shape discriminator (DPSD) has been successfully tested on one central chord of the JET neutron profile monitor and spectral information has also been obtained. Neutron spectrometry results obtained during the last JET experimental campaigns illustrate the measurement capabilities and indicate their potential use on ITER. Several projects are in progress to further develop such diagnostic capabilities and these are briefly summarized.

• OSTI ID: 21136781
• Journal Information: AIP Conference Proceedings, Vol. 988, Issue 1; Conference: International conference on burning plasma diagnostics, Varenna (Italy), 24-28 Sep 2007; Other Information: DOI: 10.1063/1.2905080; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA). JET EFDA Contributors; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
COUNTING RATES
IONS
ITER TOKAMAK
JET TOKAMAK
JT-60U TOKAMAK
MAGNETIC FLUX
NEUTRON DETECTION
NEUTRON SOURCES
NEUTRON SPECTRA
NEUTRON SPECTROSCOPY
NEUTRONS
PLASMA
PLASMA DIAGNOSTICS
PROTONS
TIME-OF-FLIGHT SPECTROMETERS