Evaluation of reconstruction errors and identification of artefacts for JET gamma and neutron tomography

Research output: Contribution to journalArticle

Authors

  • Dmitry Terentyev
  • Teddy Craciunescu
  • Andrea Murari
  • Ivan Lupelli
  • Ana Fernandes
  • Sergei Sharapob
  • Ion Tiseanu
  • Vasile Zoita
  • JET Contibutors

Institutes & Expert groups

  • National Institute for Laser, Plasma and Radiation Physics, Magurele Bucharest
  • Consorzio RFX, ricerca formazione innovazione, association EURATOM-ENEA
  • Sapienza - Università di Roma
  • CCFE - Culham Centre for Fusion Energy
  • IST - Instituto Superior Tecnico Lisboa - Portugal

Documents & links

DOI

Abstract

The Joint European Torus (JET) neutron profile monitor ensures 2D coverage of the gamma and neutron emissive region that enables tomographic reconstruction. Due to the availability of only two projection angles and to the coarse sampling, tomographic inversion is a limited data set problem. Several techniques have been developed for tomographic reconstruction of the 2-D gamma and neutron emissivity on JET, but the problem of evaluating the errors associated with the reconstructed emissivity profile is still open. The reconstruction technique based on the maximum likelihood principle, that proved already to be a powerful tool for JET tomography, has been used to develop a method for the numerical evaluation of the statistical properties of the uncertainties in gamma and neutron emissivity reconstructions. The image covariance calculation takes into account the additional techniques introduced in the reconstruction process for tackling with the limited data set (projection resampling, smoothness regularization depending on magnetic field). The method has been validated by numerically simulations and applied to JET data. Different sources of artefacts that may significantly influence the quality of reconstructions and the accuracy of variance calculation have been identified.

Details

Original languageEnglish
Article number013502
Pages (from-to)1-9
Number of pages9
JournalReview of Scientific Instruments
Volume87
Issue number1
DOIs
StatePublished - 1 Jan 2016

Keywords

  • Image-reconstruction, Noise-propeerties, Likelihood reconstruction, Maximum-Likelihood, algorithms, resolution, emission, propagation

ID: 5647812