SU1368659A1 - Method of producing radiation of impurities in gases at low temperatures - Google Patents

Abstract

The invention relates to the optics of emitting media and can be used for pumping lazergaps of media and analytical spectroscopy purposes. The goal is to increase the intensity of radiation and increase the efficiency of use of the excitation energy. A constant stream of gas mixture is fed to the cooled surface. Above the surface, the pressure is maintained less than the gas pressure at the triple point. The surface temperature is maintained at the sublimation temperature of the feed gas in a solidified state. 1 il.

Description

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. The invention relates to optics of emitting media, in particular, methods for obtaining emission spectra of various substances in a mixture, for example, with inert gases, nitrogen, hydrogen, and can be used to pump laser media, to obtain three-dimensional and axial-plex molecules for an entire analytical spectroscopy, etc.

The purpose of the invention is to increase the intensity of radiation spectra of a wide class of impurity atoms and molecules (including dissociative population of terms), as well as to increase the efficiency of using the energy invested in the excitation without significantly limiting the excitation powers.

The implementation of the method is possible by simultaneously meeting the following conditions: the existence of a constant mixture flow to the surface and maintaining this surface temperature near critical values close to the sublimation temperature of the solidified feed gas, and maintaining a surface pressure lower than the gas pressure at the triple point. Near the sublimation temperature of the solid phase, condensation is accompanied by a multiple exchange of particles between the gas and the solid phase, i.e. there is a consistent change of sorption and desorption of particles. If the electron beam is initially excited by a solid phase, then the dissociative radiation of the impurity molecule can already occur in the gas phase after desorption. This is all the more possible since the characteristic desorption times are 10 s, and the flash time is much longer (A-10 8-10 s). The existence of a constant flow of particles onto the surface maintains a dynamic equilibrium between sorption and desorption. At the same time, it is known that the highest initial excitation densities of atomic and p-type molecules, which are then intercepted by the impurity, are achieved in the solid and in the gas phase. Therefore, for example, the coefficient of conversion of the electron beam energy into the density of natural excitations of cryo-matrices (of the Xej type) reaches 30%, and in the gas does not exceed 15%. However, dissociation processes are much easier in gas and weakened.

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nonradiative loss. Thus, the excitation of simultaneously existing gas and solid phases in the proposed method leads to an increase in the utilization rate of the excitation energy, a decrease in radiation losses, and an increase in the probability of dissociative population of terms. As a consequence, there is a giant increase in the intensity of the radiation. This effect is maximum at a temperature equal to the temperature of sublimation of the solid phase of the gas. In the proposed method, there are no significant restrictions on the amount of energy invested, because an increase in the excitation power only shifts down the critical area of the sublimation mode down in temperature.

The drawing shows a device with which the proposed method can be implemented.

The device contains a cryostat 1 with 25 adjustable temperature, an electron gun 2, a gas inlet tube 3, a heated Knudsen cell 4 containing an impurity substance, a sapphire or copper substrate 5.

The method is carried out in the following manner.

The substrate 5 is cooled to the temperature of sublimation of the phase of the feed gas, known for each gas from the (P – T) solid-gas equilibrium curves. For example, for neon, the temperature of sublimation at a pressure of 10 - 10 mm Hg. is 9-11 K. A flow of inert gas to the substrate 5 is created through the inlet pipe 3. At the same time, a stream of impurity molecules, for example Hgl / i, is created from the Knudsen cell 4. In this case, both streams are mixed on the substrate. The pressure P in the cryostat with the gas flow remains constant during the measurements due to the freezing of a part of the particles not condensed on the substrate on other components cooled to 5 K. The electron beam from the gun 2 is directed to the substrate 5 and then the received radiation is recorded. The substrate temperature is maintained at all times during the measurements.

The measurement data and their analysis suggest that the proposed method gives an increase in the intensity of luminescence not less than 100 times using the example of Hgl in neon, which gives a higher

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Claims (1)

Claim These features confirm that the spectrum is formed under conditions of partial gas condensation with subsequent desorption. Thus, when using the proposed method, the efficiency of using the energy invested in the excitation is increased, and the radiation intensity is greatly increased. Intense glow can even be obtained from dissociating molecules. This is especially important, since it allows us to talk about the possibility of a noticeable increase in the efficiency of laser systems on such molecules. The proposed method does not require large gas consumption. Intense A method of producing radiation of an impurity in gases at low temperatures by condensing a mixture on a cooled surface and exciting the resulting solid sample with an electron beam, characterized in that, in order to increase the radiation intensity and increase the efficiency of use of excitation energy, a constant mixture flow to the cooled surface over which maintain a pressure lower than the gas pressure at the triple point, and its temperature is kept equal to the sublimation temperature of the feed gas in the hardened state ii.