1.4 The Resonance Fluorescence Method for Hydrogen Plasma …
35
out with the help of the monochromator with the prism (4) made of MgF 2 . Exciting
light passed in the monochromator was absorbed by the filter (5). The third harmonic
generation radiation was registered with the help of the electron multiplier IB (6),
long-wave sensitivity limit of which is ≈200 nm.
Figure 1.23b shows the dependence of the third harmonic intensity on the pressure. Experimental curve (the third harmonic wavelength λ = 123.2 nm) has strong
maximum under the pressure of 25–30 Torr (Fig. 1.23b). By preliminary estimation,
generating energy on the wavelength of 123.2 nm is not less than 1 kJ. Near resonance line, λ = 123.6 nm krypton was the medium with anomalous dispersion. The
maximum on the curve corresponds to the condition of phase matching of interacting
waves. For generating power increasing, it is possible to make larger krypton pressure and to reconstruct phase matching condition by means of adding buffer gas with
positive dispersion, for example, argon.
It is possible to assume that generating power increase due to adding of buffer
gas and also the changes of some settings makes it possible to get generation on the
wavelength of 121.6 nm.
Fig. 1.23 a Scheme of the experimental setup for producing coherence radiation in vacuum spectral
range (123.2 nm); b dependence of radiation third harmonic intensity generating near resonance
krypton line on the pressure. Reprinted from [54] with permission
35
out with the help of the monochromator with the prism (4) made of MgF 2 . Exciting
light passed in the monochromator was absorbed by the filter (5). The third harmonic
generation radiation was registered with the help of the electron multiplier IB (6),
long-wave sensitivity limit of which is ≈200 nm.
Figure 1.23b shows the dependence of the third harmonic intensity on the pressure. Experimental curve (the third harmonic wavelength λ = 123.2 nm) has strong
maximum under the pressure of 25–30 Torr (Fig. 1.23b). By preliminary estimation,
generating energy on the wavelength of 123.2 nm is not less than 1 kJ. Near resonance line, λ = 123.6 nm krypton was the medium with anomalous dispersion. The
maximum on the curve corresponds to the condition of phase matching of interacting
waves. For generating power increasing, it is possible to make larger krypton pressure and to reconstruct phase matching condition by means of adding buffer gas with
positive dispersion, for example, argon.
It is possible to assume that generating power increase due to adding of buffer
gas and also the changes of some settings makes it possible to get generation on the
wavelength of 121.6 nm.
Fig. 1.23 a Scheme of the experimental setup for producing coherence radiation in vacuum spectral
range (123.2 nm); b dependence of radiation third harmonic intensity generating near resonance
krypton line on the pressure. Reprinted from [54] with permission