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The total cross section as a function of electron energy for recombination of electrons with room temperature NO+ has been measured with a trapped ion technique. Measurements were made in the electron energy range 0.045–4 eV with an energy resolution between 0.045 and 0.120 eV, and the cross sections, which showed some structure, ranged from 1.25 × 10−14 cm² at the lowest energy to 1.7 × 10−16cm² at the highest energy. Similar measurements were made on O2+, the species used to calibrate the apparatus geometry. A Maxwellian distribution of electron velocities was used with the measured cross sections to calculate rate constants, giving values extending to electron temperatures as high as 40,000°K. Comparison with previously measured rate coefficients at lower temperatures is quite satisfactory.

The electron time decay in an afterglow following a short pulsed d.c. discharge in CO has been investigated using microwave diagnostic techniques. The gas was heated to an average temperature of 775 °K. Two-body electron-ion recombination and ambipolar diffusion were found to be the only important electron removal mechanisms present in the pressure interval [Formula: see text] Torr with the rate constants αr = 3.9 × 10−7 cm3 s−1 and Dap0 = 372 cm2 s−1 Torr respectively. If we postulate a T−γ dependence for αr, comparison with room temperature results yields γ = 0.57. The diffusion coefficient appears to increase strongly with temperature based upon an estimated zero field mobility for CO+in CO at 273 °K found in the literature.

As one of the reserches on atomic collision problems, the measurements of the ion-electron recom bination cross section are intended. The techniques used are improved crossed-beam method and mass spectrometric one. The construction of the apparatus has been finished. And some preliminary experiments were performed for testing the availability of the apparatus and the efficiency of the neutralized ion detector. In this paper, the characteristics of the apparatus, the experimental difficulties and some results so far obtained are described.

The method described in paper I for the evaluation of π (the probability that a grain be impressioned) has been applied to ~ 50 tracks, observed in Ilford G5 Plates and belonging to identifiable particles of a given range. Experimental data have been plotted versus energy loss and compared with the expression given by P. Demers. It is recognized that some modification of the theory is required to account for the results. In fact, it is shown that the discrepancies can be made to disappear if the effect of the electron recombination inside the grain is suitably taken into account.

From a comparison of ionospheric changes at F1 and F2 heights it is found that most of the variations in ƒoF2 can be attributed to variations in the incident ionizing radiation and in the rate of electron recombination. The ionizing radiation follows fairly closely the 2800 Mc/s solar radio flux. The recombination rate is affected by ionospheric storms and travelling disturbances, and it also shows a steady drift over the period studied.

We investigate ion-molecule charge exchange followed by dissociative electron recombination with molecular ions due to the presence of common impurities in a plasma-containment device. For a ${\mathrm{He}}^{+}$ plasma with ${\mathrm{N}}_{2}$ impurity, the ionic constituency of plasmas is changed from ${\mathrm{He}}^{+}$ to nitrogen ions with a time constant ${\ensuremath{\tau}}^{*}$ given by ${\ensuremath{\tau}}^{*}P({\mathrm{N}}_{2})\ensuremath{\simeq}24$ msec $\ensuremath{\mu}$ Torr. However, those ion-molecular recombination processes are not responsible for the enhanced plasma loss in the Princeton spherator at the best vacuum condition.

S>Microwave diagnostic methods were used to measure the effective electron recombination rate alpha /sub r/ in the afterglow of a pulsed dc discharge as a function of gas temperature T and pressure p in the ranges 300 to 735 deg K and 0.5 to 6.0 mm Hg, respectively. It is found that alpha /sub r/ has a value of 1.2 x 10/sup -7/ cm/sup 3/ sec/sup -1/ at T = 300 deg K and p = 1.0 mm Hg, which is considerably smaller than most previously reported values. Over this temperature range alpha /sub r/ decreased with T, by roughly one order of magnitude at p = 2.0 mm Hg, and more than two orders of magnitude at p = 6.0 mm Hg, the sharpest decrease taking place above T = 800 deg K. The increase of alpha with pressure became smaller as the temperature was raised, ultimately leading to a decrease of alpha /sub r/ with pressure at T = 735 deg K. (auth)

A possible mechanism for electron recombination with a hole trapped at an edge dislocation in Ge is considered. It is assumed that the electron transfers a part of its energy to the oscillations of the charge system along the dislocation, being itself captured in one of the vibrational states. The probability of such process is estimated by the harmonic oscillator approximation. The calculated values of the lifetime are in order-of-magnitude agreement with those observed experimentally in plastically deformed germanium. Es wird ein Rekombinationsmechanismus untersucht, bei dem ein Elektron mit einem Loch rekombiniert, das an einer Stufenversetzung im Ge angehaftet ist. Es wird angenommen, das das Elektron einen Teil seiner Energie an die Schwingungen des Ladungssystems entlang der Versetzung abgibt, da es selbst in einen der Schwingungszustande eingefangen ist. Die Wahrscheinlichkeit fur das Auftreten eines derartigen Prozesses wurde in der Naherung harmonischer Oszillatoren berechnet. Die berechneten Werte fur die Lebensdauer stimmen grosenordnungsmasig mit den an plastisch deformierten Ge gefundenen Werten uberein.

The work reported here establishes the existence of $\mathrm{He}_{3}^{}{}_{}{}^{+}$ and $\mathrm{He}_{4}^{}{}_{}{}^{+}$ at room temperature (300\ifmmode^\circ\else\textdegree\fi{}K) in a helium afterglow. The data presented in this paper indicate that the often-measured electron-ion recombination coefficient in 300\ifmmode^\circ\else\textdegree\fi{}K helium afterglows is mainly attributable to electron recombination with $\mathrm{He}_{3}^{}{}_{}{}^{+}$ rather than, as is usually assumed, with the dominant ion $\mathrm{He}_{2}^{}{}_{}{}^{+}$.

We propose a mechanism whereby electron capture by neutral donors can become significant in electron recombination in n-type semiconductors at liquid helium temperatures.