The results of the measurements of the neutron and gamma radiation produced in the 9 Be( 3 He,pγ) 11 B and 9 Be( 3 He,nγ) 11 C nuclear reaction at the 2.57 MeV energy of the 3 He ions are represented. The measurements were carried out with organic scintillation detector BC-501A and semiconductor HPGe spectrometers. Gamma-ray spectra were measured at 0°, 30°, 60°, 90° and 120° angles. The shapes of the gamma lines 6.9 MeV from the 9 Be( 3 He,nγ) 11 C reaction and 8.92 MeV from the 9 Be( 3 He,nγ) 11 C were obtained. The angular distribution of protons populating the 8.92 MeV energy level of the 11 B nucleus was reconstructed. The energy distribution of the neutrons produced in the 9 Be( 3 He,nγ) 11 C reaction was measured (obtained).

Gamma detectors measures emission from nuclear reactions with fast ions, and also bremsstrahlung radiation from runaway electrons decelerating on the bulk plasma and vacuum vessel components. Diagnostic under consideration gives data on distribution functions of these particles, which play an important and often even the crucial role in many plasma phenomena: burning, energy balance, instabilities, etc. Dedicated ITER spectrometer is under development by Ioffe Institute Cyclotron Laboratory team. Design of system will accumulate most of the experience of the analogous systems currently in use and also will have to solve new technical challenges due to the requirement to operate in fusion reactor conditions of ITER. Discussion on the last stages of design preparation, including retrospective neutronic analysis and necessary mockup tests, is given below.

Gamma-ray spectrometry on ITER can provide information both on confined fusion alpha particles for optimization of plasma heating and runaway electrons, which is important for safe reactor operations. For the purpose of deconvolution of gamma-ray spectra recorded in fusion plasma experiments the DeGaSum code has been developed. The code can be applied for processing of both spectra of monoenergetic gamma rays, which are born in nuclear reactions produced by alpha particles and other fast ions, and continuous bremsstrahlung spectra generated by runaway electrons in the MeV range in the plasma and reactor structure materials. Gamma-ray spectrometer response functions and bremsstrahlung spectra generated by electrons in the MeV energy range are calculated and used in the DeGaSum code. The deconvolution of the discrete spectra allows the identification of nuclear reactions, which give rise to gamma rays, and the calculation of their intensities. By applying the code for continuous hard x-ray spectra, the runaway electron energy distribution can be inferred. It can provide the maximal energy of runaway electrons with accuracy, which satisfies the ITER project requirements. The code has been used for processing of spectra recorded in JET experiments. An application of the deconvolution technique for gamma-ray emission measurements on ITER is discussed.

Results are presented from experimental studies of runaway electrons in the ohmic heating regime in the Globus-M tokamak. The periodical hard X-ray bursts observed with the help of two hard X-ray spectrometers with high time resolution are attributed to MHD oscillations in the plasma core and at the periphery.

The potentialities and design features of a combined diagnostic technique for studying accelerated electrons are considered, The results obtained with this technique in the FT-2 tokamak are presented. The diagnostic method is based ore simultaneous measurements of microwave synchrotron emission in the f(ce)-2f(ce) frequency range and collective emission in the f(p)-2f(p) frequency range, as well as the intensity and energy spectrum of hard X-ray emission, By using these diagnostics, a beam of accelerated electrons with energy up to 1 MeV was detected in the initial stage of the FT-2 discharge. This beam exists during the Ohmic heating stage. For N-e0 < 4 x 10(13) cm(-3), due to fairly large nonuniformity of N-e(r) and ripples of B-T, this beam continuously drives fan instability. In denser plasma, N-e0 > 4 x 10(13) cm(-3), when runaway electrons are freely accelerated up to an energy of several MeV, emission of intense microwave radiation in the frequency range f(p)-2f(p) is observed. It seems that this emission, whose power depends weakly on N-e, is not a result of conversion of plasma modes and may be the thermal-electron bremsstrahlung emission that is amplified up to saturation level by a beam of relativistic electrons moving in the rippled magnetic field B-T. In experiments On the lower hybrid current drive and ion heating, the regime of high-frequency pumping of the plasma is realized in the presence of a beam of accelerated electrons. A partial absorption of the pumping wave by accelerated electrons increases the efficiency of the current drive and leads to excitation of intense plasma oscillations. For N-e0 > 4 x 10(13) cm(-3), when the absorption region is localized near the limiter, the efficiency of lower hybrid heating can decrease.