Development of single crystal diamond neutron detectors and test at JET tokamak

Abstract

During the 2005–2007 JET experimental campaigns a Single Crystal Diamond (SCD) detector covered with a 2-μm thick LiF film 95% enriched in 6Li was installed at JET and operated continuously during the whole experimental campaign with the goal to measure both the total and the time-dependent neutron emission from plasmas. After reviewing the history of diamond as neutron detector for tokamak application, this paper reports on the experimental measurements performed during that time window. The results are compared with those obtained with detectors routinely working at JET (Fission Chambers and silicon diodes). In particular it was demonstrated that using an SCD detector covered with a 6LiF film it has been possible to discriminate between the total and the 14-MeV neutrons coming from triton burn-up. This allowed, for the first time using a single detector, the simultaneous measurement of both the total and 14-MeV neutron yields as well as their time dependency with very good reliability and stability.