Data processing in the data acquisition system of the vertical neutron camera plasma diagnostics at the ITER tokamak

Data acquisition system for a neutron spectrometer with a remote diamond detector

“…This result is determined by two components: the relative energy resolution of the spectrometer in the region of the peak (3.25%) and the spread of the alpha particles energy (5%), caused by their scattering in the air gap between the 238 Pu source and the diamond detector. The figure 11 shows the response function to 14 MeV neutrons of the spectrometric path prototype of the data acquisition system of the ITER VNC [9,17], which has the data processing unit identical to the spectrometer considered in this paper. The counting rate during the formation of the specified distribution was ∼1.5 × 10 6 events per second, and the duration of the data collection interval was equal to 20 milliseconds.…”

“…Due to this, for example, according to the Doppler broadening of the line with 8. 4 MeV energy, corresponding to the nuclear reaction 12 C(n, 𝛼) 9 Be, the deuterons and tritons temperature can be determined in the plasma. In experiments with deuterium plasma, the 12 C(n, n ) 12 C channel with 4.4 MeV reaction energy is of particular interest also.…”

“…The latter factors significantly complicate the event processing procedures aimed at generating measurements results of the plasma ionic components temperature and the intensity of thermonuclear reactions. This is especially true for real time mode, the implementation of which is necessary to fix the nature of these parameters behavior in time, or when the outputs are included in the set of parameters used by the discharge control system [9]. This work is devoted to development of the neutron spectrometer prototype for ITER Vertical Neutron Chamber (VNC) data acquisition system, operating in real time.…”