skip to main content

SciTech ConnectSciTech Connect

Title: Phillips-Tikhonov regularization with a priori information for neutron emission tomographic reconstruction on Joint European Torus

A method of tomographic reconstruction of the neutron emissivity in the poloidal cross section of the Joint European Torus (JET, Culham, UK) tokamak was developed. Due to very limited data set (two projection angles, 19 lines of sight only) provided by the neutron emission profile monitor (KN3 neutron camera), the reconstruction is an ill-posed inverse problem. The aim of this work consists in making a contribution to the development of reliable plasma tomography reconstruction methods that could be routinely used at JET tokamak. The proposed method is based on Phillips-Tikhonov regularization and incorporates a priori knowledge of the shape of normalized neutron emissivity profile. For the purpose of the optimal selection of the regularization parameters, the shape of normalized neutron emissivity profile is approximated by the shape of normalized electron density profile measured by LIDAR or high resolution Thomson scattering JET diagnostics. In contrast with some previously developed methods of ill-posed plasma tomography reconstruction problem, the developed algorithms do not include any post-processing of the obtained solution and the physical constrains on the solution are imposed during the regularization process. The accuracy of the method is at first evaluated by several tests with synthetic data based on various plasma neutronmore » emissivity models (phantoms). Then, the method is applied to the neutron emissivity reconstruction for JET D plasma discharge #85100. It is demonstrated that this method shows good performance and reliability and it can be routinely used for plasma neutron emissivity reconstruction on JET.« less
Authors:
; ;  [1] ;  [2] ;  [3] ; ;  [2] ;  [2] ;  [4] ;  [5] ;  [6]
  1. Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Krakow (Poland)
  2. CCFE, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)
  3. (Italy)
  4. (Sweden)
  5. IAP, National Institute for Laser Plasma and Radiation Physics, Bucharest (Romania)
  6. (United Kingdom)
Publication Date:
OSTI Identifier:
22482780
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 86; Journal Issue: 9; Other Information: (c) 2015 EURATOM; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; EMISSIVITY; JET TOKAMAK; NEUTRON EMISSION; NEUTRONS; OPTICAL RADAR; PLASMA; THOMSON SCATTERING