Help Of Microwaves Research Articles

Microwave spectrum and internal rotations of ethylene glycol. I. Glycol-O-d2

The microwave spectrum of a dideuterated form of ethylene glycol (glycol-O-d2, CH2ODCH2OD) has been investigated in the frequency range from 18 to 50 GHz. Among the many transitions observed, 64 rotational transitions could be assigned with the help of microwave—microwave double resonance experiments. All transitions occurred as doublets due to large amplitude motions in the molecule. A semirigid molecular model which features a collective concerted internal rotation of the two OD groups on the Born—Oppenheimer surface has been used for the assignment and analysis. This model allowed a satisfactory interpretation of the assigned transitions. From the centers of the doublets the following rotational constants and the dipole moment of a hypothetical rigid rotor could be determined: A = 14394.63(17) MHz, B = 5276.27(24) MHz, C = 4323.53(20) MHz, μa = 2.166(37)D, μb = 0.74(18)D, and μc = 0.75(21)D. An empirical potential function for the concerted internal rotation of the OD groups has been derived from the measured doublet splittings.

Microwave Spectrum of Mono-deuterated Acetyl Cyanide CH2DCOCN and Complete rs- and r0-structure of Acetyl Cyanide

Abstract Microwave spectra of symmetric and asymmetric forms of monodeuterated acetyl cyanide CH2DCOCN have been observed and measured. Significant differences occur between our assign­ment and those of Krisher and Wilson1. We have confirmed all our assignments with the help of microwave - microwave double resonance (MW-MW-DR) experiments. By fitting about twelve low J transition frequencies to a rigid rotator, accurate values for the rotational constants have been obtained. From the analysis of the quadrupole hyperfine splittings of some of the tran­sitions, the nuclear quadrupole coupling constants are also determined. Using the measured rotational constants for a number of molecular isotopic species of Refer­ence (1), and in addition those measured in this laboratory for the 15N, monodeuterated and normal species (determined with greater accuracy), a complete rs-and ro-structure has been calculated. The important conclusions are - i) the methyl group does not possess C3V symmetry and ii) the Ccarbonyl, - Ccyanide and C - N bonds are collinear within the accuracy of measurements.

Recombination of Impact Ionized Excess Carriers in Tellurium

AbstractThe recombination time of p‐type tellurium was measured dependent on carrier mobility and carrier density at 77 K. Excess carriers were produced by impact ionization in strong electric fields to achieve large excess carrier concentrations. The recombination of the excess carriers was observed by the help of microwaves, the rise time of the experimental apparatus was less than 5 × 10−9 s. The experimental data can be interpreted as the superposition of a slow and a fast exponential decay. The results can be explained by an extended Shockley‐Read model. The energy level and the concentration of the trapping and recombination centers can be deduced from the experimental data.

The experiment on elimination of cone losses in the magnetostatic mirror by help of microwaves

The passing of plasma bunches with the ion longitudinal energy about 1 keV and density n > 10 12 cm -3 through the combined microwave — magnetostatic barrier is experimentally studied. It is shown that cone losses can be removed providing the wave frequency “ω” equal to the upper hybrid frequency ( ω = (ω 2 c+ω 2 p) 1 2 ) .