Inversion methods for analysis of neutron brightness measurements in tokamaksFunded under: FP2-FUSION 10C
The problem of determining the neutron emissivity from neutron brightness measurements in magnetic fusion plasmas is addressed. A detailed analysis of the JET neutron brightness data was carried out. The two-dimensional features of the neutron emissivity cannot be determined with sufficient accuracy due to the experimental uncertainty of the brightness data. In cases where the neutron emissivity contours are known, the generalised Abel inversion of the neutron brightness data allows a fairly accurate determination of the radial emissivity profiles. These profiles, together with the experimental electron density profiles and the average Z(eff) values, were used to deduce the deuterium temperature profiles in plasmas with Maxwellian deuterium velocity distributions. Results of the application of this method to the analysis of neutron brightness profiles are presented, using representative JET data. In general, the accuracy of the results depends crucially on the plasma purity, so that the neutron method is applicable only in cases where Z(eff) is small (typically Z(eff)<3). It is concluded that the generalised Abel inversion of the neutron brightness data can be used for the diagnosis of JET plasmas, but with limited applicability as to plasma conditions.
Bibliographic Reference: Report: JET-R(90)03 EN (1990) 63 pp.
Availability: Available from the Publications Officer, JET Joint Undertaking, Abingdon, Oxon. OX14 3EA (GB)
Record Number: 199110096 / Last updated on: 1994-12-02
Original language: en
Available languages: en