Ion Transport and Ion-Molecule Reactions of Negative Ions in Sf6

Author(s):  
Yoshiharu Nakamura
1968 ◽  
Vol 48 (5) ◽  
pp. 2349-2352 ◽  
Author(s):  
John G. Dillard ◽  
J. L. Franklin

2016 ◽  
Author(s):  
Tamás Kovács ◽  
John M. C. Plane ◽  
Wuhu Feng ◽  
Tibor Nagy ◽  
Martyn P. Chipperfield ◽  
...  

Abstract. This study presents a new ion-neutral chemical model coupled into the Whole Atmosphere Community Climate Model (WACCM). The ionospheric D region (altitudes ~ 50–90 km) chemistry is based on the Sodankylä Ion and Neutral Chemistry (SIC) model, a 1-dimensional model containing 306 ion-neutral and ionrecombination reactions of neutral species, positive and negative ions, and electrons. The SIC mechanism was reduced using the Simulation Error Minimization Connectivity Method (SEM-CM) to produce a reaction scheme of 181 ion-molecule reactions. This scheme describes the concentration profiles at altitudes between 20 km and 120 km of a set of major neutral species (HNO3, O3, H2O2, NO, NO2, HO2, OH, N2O5) and ions (O2+, O4+, NO+, NO+(H2O), O2+(H2O), H+(H2O), H+(H2O)2, H+(H2O)3, H+(H2O)4, O3−, NO2−, O−, O2, OH−, O2−(H2O), O2−(H2O)2, O4−, CO3−, CO3−(H2O), CO4−, HCO3−, NO2−, NO3−, NO3−(H2O), NO3(H2O)2, NO3−(HNO3), NO3−(HNO3)2, Cl−, ClO−), which agree with the full SIC mechanism within a 5 % tolerance. Four 3D model simulations were then performed, using the impact of the January 2005 Solar Proton Event (SPE) on D region HOx and NOx chemistry as a test case of four different model versions: the standard WACCM (no negative ions and a very limited set of positive ions); WACCM-SIC (standard WACCM with the full SIC chemistry of positive and negative ions); WACCM-D (standard WACCM with a heuristic reduction of the SIC chemistry, recently used to examine HNO3 formation following an SPE); and WACCM-rSIC (standard WACCM with a reduction of SIC chemistry using the SEM-CM Method). Standard WACCM misses the HNO3 enhancement during the SPE, while the full and reduced model versions predict significant NOx, HOx and HNO3 enhancements in the mesosphere during solar proton events. The SEM-CM reduction also identifies the important ion-molecule reactions that affect the partitioning of odd nitrogen (NOx), odd hydrogen (HOx), and O3 in the stratosphere and mesosphere.


1967 ◽  
Vol 22 (5) ◽  
pp. 700-704
Author(s):  
K. Jäger ◽  
A. Henglein

Negative ion formation by electron impact has been studied in nitromethane, nitroethane, nitrobenzene, tetranitromethane, ethylnitrite and ethylnitrate. Appearance potentials, ionization efficiency curves and kinetic energies of negative ions were measured by using a Fox ion source. The electron affinities of C2H5O and of C (NO2)3 are discussed as well as the energetics of processes which yield NO2-. The electron capture in nitrobenzene and tetranitromethane leads to molecular ions [C6H5NO2~ in high, C (NO2)4 in very low intensity] besides many fragment ions. A number of product ions from negative ion-molecule reactions has also been found.


2016 ◽  
Vol 9 (9) ◽  
pp. 3123-3136 ◽  
Author(s):  
Tamás Kovács ◽  
John M. C. Plane ◽  
Wuhu Feng ◽  
Tibor Nagy ◽  
Martyn P. Chipperfield ◽  
...  

Abstract. This study presents a new ion–neutral chemical model coupled into the Whole Atmosphere Community Climate Model (WACCM). The ionospheric D-region (altitudes ∼  50–90 km) chemistry is based on the Sodankylä Ion Chemistry (SIC) model, a one-dimensional model containing 307 ion–neutral and ion recombination, 16 photodissociation and 7 photoionization reactions of neutral species, positive and negative ions, and electrons. The SIC mechanism was reduced using the simulation error minimization connectivity method (SEM-CM) to produce a reaction scheme of 181 ion–molecule reactions of 181 ion–molecule reactions of 27 positive and 18 negative ions. This scheme describes the concentration profiles at altitudes between 20 km and 120 km of a set of major neutral species (HNO3, O3, H2O2, NO, NO2, HO2, OH, N2O5) and ions (O2+, O4+, NO+, NO+(H2O), O2+(H2O), H+(H2O), H+(H2O)2, H+(H2O)3, H+(H2O)4, O3−, NO2−, O−, O2, OH−, O2−(H2O), O2−(H2O)2, O4−, CO3−, CO3−(H2O), CO4−, HCO3−, NO2−, NO3−, NO3−(H2O), NO3−(H2O)2, NO3−(HNO3), NO3−(HNO3)2, Cl−, ClO−), which agree with the full SIC mechanism within a 5 % tolerance. Four 3-D model simulations were then performed, using the impact of the January 2005 solar proton event (SPE) on D-region HOx and NOx chemistry as a test case of four different model versions: the standard WACCM (no negative ions and a very limited set of positive ions); WACCM-SIC (standard WACCM with the full SIC chemistry of positive and negative ions); WACCM-D (standard WACCM with a heuristic reduction of the SIC chemistry, recently used to examine HNO3 formation following an SPE); and WACCM-rSIC (standard WACCM with a reduction of SIC chemistry using the SEM-CM method). The standard WACCM misses the HNO3 enhancement during the SPE, while the full and reduced model versions predict significant NOx, HOx and HNO3 enhancements in the mesosphere during solar proton events. The SEM-CM reduction also identifies the important ion–molecule reactions that affect the partitioning of odd nitrogen (NOx), odd hydrogen (HOx) and O3 in the stratosphere and mesosphere.


1976 ◽  
Vol 9 (1) ◽  
pp. 38-40 ◽  
Author(s):  
D Vogt ◽  
J Mischke ◽  
W Dreves

Sign in / Sign up

Export Citation Format

Share Document