Dissociable Contributions Research Articles

Dissociative recombination contributions to I(5577) and I(6300) [OI] and NmF2 enhancements resulting from moderate proton PCA events

We investigate the dissociative recombination contribution to I(5577) and I(6300) of [OI] as a function of low energy cutoff for two measured solar proton spectra. The volume ionization rate profiles used in the calculation are obtained using a detailed atomic cross section approach in the continuous slowing down approximation. The ratio of the dissociative recombination contribution to the direct impact contribution for both the 5577 Å and 6300 Å [OI] emissions is found to be dependent upon the low energy cutoff. This ratio has a nominal value of ∼2.0 for the 5577 Å [OI] emission and ∼0.25 for the 6300 Å [OI] emission. The I(5577)/I(3914) and I(6300)/I(3914) ratios including the direct and dissociative recombination contributions are strongly dependent upon the low energy cutoff of the spectrum. We have also investigated F-layer enhancements resulting from the low energy spectrum component. For the Mizera et al. (1972) spectrum with a low energy cutoff of 12.4 keV, we find an N m F2 of ∼4.5 × 10 3 electrons/cm 3 or about 10 per cent of the ionization required to maintain the dip pole at a value of 5 × 10 4 electrons/cm 3. Extension of the cutoff to 1 keV results in ∼1 × 10 4 electrons/cm 3, or about 20 per cent of the required maintenance ionization.

Asymptotic behaviour of a dual two-pomeron graph in the missing-mass resonance region

The diffraction dissociation contribution to the inclusive cross-section is studied on the basis of a nonplanar dual two-loop amplitude. The discussion is restricted to the resonance region in missing mass. Pomeron form factors describing coupling to a scalar particle and a resonance of spinj are defined. In the fixed-angle limit a universal exponential behaviour dominating the treeB 6-contribution has been found.

On determining the major SAR arc properties from a few measurable parameters

The stable auroral red (SAR) arc is excited primarily by the conduction of heat from the magnetosphere into the ionosphere. The energy heats the ambient F region electrons that in turn excite the atomic oxygen emission at 6300 A within the arc. The major SAR arc properties are controlled by only a few ionospheric and atmospheric parameters, i.e., the topside heat flow rate in the electron gas from the magnetosphere to the ionosphere, the electron number density at the F2 peak, and the exospheric temperature of a model atmosphere. Figures are presented that relate major SAR arc properties to measurable parameters and enable an observer to determine the gross SAR arc characteristics from either ground-based measurements of the (O I) 6300-A emission rate and number density of the F2 peak or satellite measurements of the electron temperature and F2 peak number density. A relationship that approximates the background dissociative recombination contribution to the (O I) 6300-A emission rate is also given.

The absorptive regge model and features of πN scattering at high energy

The absorptive Regge cut associated with ϱ exchange is calculated in detail as a function of the ϱ, P and P′ Regge poles in the Fourier-Bessel representation. The ϱ ′chooses nonsense′ at α ϱ = 0 and has no built-in crossover zero. The vacuum pole amplitudes are constrained to satisfy the relation νB (+) A′ (+) = N . Good fits to πN charge exchange and elastic data are obtained for N = −1 and −2. The elastic crossover is well reproduced and is explained as a co-operation between the effect of the cut and having N negative. The effect of diffractive dissociation contributions to the Regge cut is considered. Their inclusion tends to worsen the fits.

Correction in the laboratory measurement of the rate constant for N 2+ + O 2 → N 2 + O 2+ at 300°K

We investigate the dissociative recombination contribution to I(5577) and I(6300) of [OI] as a function of low energy cutoff for two measured solar proton spectra. The volume ionization rate profiles used in the calculation are obtained using a detailed atomic cross section approach in the continuous slowing down approximation. The ratio of the dissociative recombination contribution to the direct impact contribution for both the 5577 Å and 6300 Å [OI] emissions is found to be dependent upon the low energy cutoff. This ratio has a nominal value of ∼2.0 for the 5577 Å [OI] emission and ∼0.25 for the 6300 Å [OI] emission. The I(5577)/I(3914) and I(6300)/I(3914) ratios including the direct and dissociative recombination contributions are strongly dependent upon the low energy cutoff of the spectrum. We have also investigated F-layer enhancements resulting from the low energy spectrum component. For the Mizera et al. (1972) spectrum with a low energy cutoff of 12.4 keV, we find an NmF2 of ∼4.5 × 103 electrons/cm3 or about 10 per cent of the ionization required to maintain the dip pole at a value of 5 × 104 electrons/cm3. Extension of the cutoff to 1 keV results in ∼1 × 104 electrons/cm3, or about 20 per cent of the required maintenance ionization.