  A new method for measuring the electron temperature of the plasma in GOL-NB
facility is proposed. The proposed method is based on measuring the ratio of
intensities of spectral lines emitted by fast atoms injected into the plasma.
The beams of fast hydrogen atoms used for plasma heating or diagnostics contain
atoms with full energy as well as atoms with fractional energies (E/2, E/3,
E/18), which arise from the dissociation of molecular ions H+2, H+3, H2O+.
Spectral lines of atoms with different energies (especially Ha) can be resolved
due to Doppler shift caused by differences in atom velocities. For low-energy
atoms, excitation occurs due to collisions with thermal electrons, while for
high-energy atoms, collision processes with plasma ions are essential.
Therefore, the intensity ratio of line fractions with different energies
depends on the electronic temperature of the plasma and can be used for its
measurement. At a beam energy of 24 keV, the method can be used to measure
electronic temperatures up to 40 eV, which is of interest for experiments on
the GOL-NB facility. To measure the temperature with an accuracy of 20 eV, it
is necessary to measure the intensity ratio of lines with percentage precision
and also measure the same precision of attenuation of the neutral beam passing
through the plasma.
