Rotational Excitation and Momentum Transfer Cross Sections for Electrons inH2andN2from Transport Coefficients

1962 ◽  
Vol 127 (5) ◽  
pp. 1621-1633 ◽  
Author(s):  
L. S. Frost ◽  
A. V. Phelps
RSC Advances ◽  
2014 ◽  
Vol 4 (109) ◽  
pp. 63817-63823 ◽  
Author(s):  
Biplab Goswami ◽  
Rahla Naghma ◽  
Bobby Antony

R-matrix and SCOP methods are used at low and high energies respectively to find e-GeF4 TCS. Electronic and rotational excitation, momentum transfer and elastic differential cross sections are also calculated. A shape resonance is observed at 5.7 eV.


2018 ◽  
Vol 29 (1) ◽  
pp. 174
Author(s):  
Jasim Mohammed salih Ali

Abstract: In this work, we were calculate the electron diffusion coefficients, such as, the drift velocity, characteristic energy, and collision frequencies using the cross sections of the momentum transfer and inelastic for electrons in CO2 from figure(1) after solving the Boltzmann transport equation numerically using the Finite-Difference Method in gas medium through applied electric field at 300 oK. The theoretical predictions were obtained in agreement with the experimental values was publishered. Keyword: CO2 lasers, Boltzmann Transport Equation, RF Discharges, Transport coefficients, Plasma discharge, Drift velocity. الخلاصة: في هذا العمل ، تم حساب معاملات انتشار الالكترونات مثل سرعة الانجراف، الطاقة الميزة و ترددات التصادم باستعمال المقاطع العرضية المرنة وغير مرنة للالكترونات في غاز ثاني أوكسيد الكاربون CO2 من شكل (1) خلال حل معادلة الانتقال لبولتزمان عددياً باستخدام طريقة التفريق المحدد في وسط غازي بعد تسليط مجال كهربائي عليه عند درجة حرارة 300 كلفن . النتائج التي تم الحصول عليها تنبأ بأنها متوافقة مع النتائج العملية المنشورة. الكلمات المفتاحية : ليزرات CO2 ، معادلة الانتقال لبولتزمان ، نموذج التفريغ ، معاملات الانتقال ، تفريغ البلازما ، سرعة الانجراف.


1987 ◽  
Vol 40 (3) ◽  
pp. 347 ◽  
Author(s):  
ZLj Petrovic ◽  
RW Crompton

Measurements of electron drift velocities have been made in pure helium and in a helium-hydrogen mixture in order to check the available inelastic cross sections for hydrogen. Although drift velocities in mixtures with helium as the buffer gas are less,sensitive to inelastic scattering by hydrogen than those with argon, the accuracy with which the momentum transfer cross section for helium is known enables the check to be made with virtually no error arising from uncertainty in the momentum transfer cross section for the buffer gas, in contrast to the situation when argon is used. A difference techrtique has been used to minimise the effect of systematic errors in the measurements. The results support the rotational and vibrational cross sections derived from the transport coefficients measured in pure hydrogen.


1993 ◽  
Vol 46 (2) ◽  
pp. 249 ◽  
Author(s):  
MJ Brennan ◽  
KF Ness

The momentum transfer cross section for electrons in krypton has been derived over the energy range Q-4 eV from an analysis of drift velocity and DT/I-' data for hydrogen-krypton mixtures. At energies in the vicinity of the Ramsauer-Townsend minimum, the present work differs significantly from derivations based on analyses of drift velocity data alone. The overall uncertainty in the derived cross section reflects the experimental errors in the transport coefficients, the uncertainty in the cross sections used to represent the hydrogen component in the mixtures, and the uncertainty associated with the X2 minimisation. The present cross section is compared with recent theoretical calculations and other experimental derivations.


Particles ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 178-192 ◽  
Author(s):  
O. Soloveva ◽  
P. Moreau ◽  
L. Oliva ◽  
V. Voronyuk ◽  
V. Kireyeu ◽  
...  

We study the influence of the baryon chemical potential μ B on the properties of the Quark–Gluon–Plasma (QGP) in and out-of equilibrium. The description of the QGP in equilibrium is based on the effective propagators and couplings from the Dynamical QuasiParticle Model (DQPM) that is matched to reproduce the equation-of-state of the partonic system above the deconfinement temperature T c from lattice Quantum Chromodynamics (QCD). We study the transport coefficients such as the ratio of shear viscosity η and bulk viscosity ζ over entropy density s, i.e., η / s and ζ / s in the ( T , μ ) plane and compare to other model results available at μ B = 0 . The out-of equilibrium study of the QGP is performed within the Parton–Hadron–String Dynamics (PHSD) transport approach extended in the partonic sector by explicitly calculating the total and differential partonic scattering cross sections based on the DQPM and the evaluated at actual temperature T and baryon chemical potential μ B in each individual space-time cell where partonic scattering takes place. The traces of their μ B dependences are investigated in different observables for symmetric Au + Au and asymmetric Cu + Au collisions such as rapidity and m T -distributions and directed and elliptic flow coefficients v 1 , v 2 in the energy range 7.7 GeV ≤ s N N ≤ 200 GeV.


1969 ◽  
Vol 22 (6) ◽  
pp. 715 ◽  
Author(s):  
RW Crompton ◽  
DK Gibson ◽  
AI McIntosh

The results of electron drift and diffusion measurements in parahydrogen have been analysed to determine the cross sections for momentum transfer and for rotational and vibrational excitation. The limited number of possible excitation processes in parahydrogen and the wide separation of the thresholds for these processes make it possible to determine uniquely the J = 0 → 2 rotational cross section from threshold to 0.3 eV. In addition, the momentum transfer cross section has been determined for energies less than 2 eV and it is shown that, near threshold, a vibrational cross section compatible with the data must lie within relatively narrow limits. The problems of uniqueness and accuracy inherent in the swarm method of cross section analysis are discussed. The present results are compared with other recent theoretical and experimental determinations; the agreement with the most recent calculations of Henry and Lane is excellent.


1990 ◽  
Vol 68 (1) ◽  
pp. 104-110 ◽  
Author(s):  
B. Plenkiewicz ◽  
P. Plenkiewicz ◽  
J.-P. Jay-Gerin

Our earlier pseudopotential calculations on electrons colliding with argon and krypton are extended to consider the elastic electron–helium scattering system. In this paper, we present detailed results for phase shifts, differential, total, and momentum-transfer cross sections for this system for incident electron energies in the range from 0 to 20 eV. These agree very well with existing experimental data and with other theoretical calculations.


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