A Method for the Estimation of the Relative Intensities of Microwave Absorption Lines

Abstract

Articles you may be interested in Line shape and intensity considerations in microwave optical magnetic resonance induced by electrons and related experimentsAn examination of the theoretical relationship between absorption and crystal response in a Stark-effect microwave spectrograph indicates that a direct proportionality exists between the absorption coefficient and the component of crystal current at the modulation frequency, provided that certain reasonable conditions are fulfilled.An experimental method is described which utilizes this principle to obtain measurements of the ratio of one absorption coefficient to another. This method involves a matching of the modulation frequency component of crystal current against an adjustable reference signal. These measurements may be used to determine the energy separation of the lower states of the lines observed, thus yielding microwave data on vibrational or torsional energy levels. Line breadth and saturation can be measured equally well with minor modifications in method.This experimental method was tested by measuring the known ratios of absorption coefficients of the carbonyl sulfide lines near 24000 mc which are assigned to various isotopic species. The range of deviation of measured ratio from known ratio was 25 percent, and this discrepancy is attributed to reflections in the microwave transmission line, particularly at the ends of the Stark electrode. The determination of molecular vibrational or torsional energy levels is discussed.

Energy Losses of Electrons Passing through an MgO Foil

“…The energy separation, 13.6 ev, of the third peak from the second peak in Table I T HE saturation of the microwave transition 7=0->l of CH 3 S1 35 has been measured by the method of Baird and Bird. 1 The results constitute the first measurement on saturation of a rotational absorption line, all other microwave saturation measurements having been made on the J =3, K-3 line of the ammonia inversion spectrum. 2 ' 3 As in the case of the ammonia line, the experimental results are described by the formula derived by Karplus and Schwinger.…”

“…This AEo is in reasonable agreement with that predicted by Burstein. 1 The discrepancies between theory and experiment are the observed AE 0 below n-10 18 cm" 3 and the form of the dependence of Eo on n. Explanation of the shift of the absorption edge below n= 10 18 cm" 3 requires the assumption that m n is even smaller than the calculated value. 1 This implies that the effective hole mass and the thermal energy gap are also somewhat lower than previously reported.…”

“…1 The discrepancies between theory and experiment are the observed AE 0 below n-10 18 cm" 3 and the form of the dependence of Eo on n. Explanation of the shift of the absorption edge below n= 10 18 cm" 3 requires the assumption that m n is even smaller than the calculated value. 1 This implies that the effective hole mass and the thermal energy gap are also somewhat lower than previously reported. 1 ' 3 Agreement between the slopes of the theoretical and experimental curves can be obtained by assuming that the effective electron mass increases linearly with the height of the Fermi level above the bottom of the conduction band.…”

“…However, the effect is not large and the maximum observed shift amounts to only 0.7 fx. 1 I T is well known that in the case of an insulator or a semiconductor there is a forbidden band above the valence band, and the width of this forbidden band is not known very accurately. Its measurement is regarded as an important problem for various reasons.…”

“…1 Table I. Though the positions of the feeble or broad peaks cannot be determined very accurately, those of the sharp peaks such as the second peak at 11.4 ev, can be measured with sufficient accuracy, in this case, for example, with an accuracy of ca ±0.1 ev.…”