e - Jonathan Tennyson University College London EMOL task group: electron-water collision data Recommendation Outer region Inner region IAEA May 2013

Transcription

1 e - EMOL task group: electron-water collision data Recommendation Jonathan Tennyson University College London Outer region Inner region IAEA May 2013

2 Asked to consider Rotational excitation: Y Itikawa J Tennyson and N J Mason Vibrational excitation: J Tennyson B Marinkovic and N J Mason Inelastic processes: J Tennyson G Garcia and Y Itikawa Total cross sections: N J Mason J Tennyson G Garcia

3 Rotational excitation: previous recommendation A.Faure, J.D. Gorfinkiel and J. Tennyson J. Phys. B 37, 801 (2004). Goes up to 5 ev for DJ up to 3. 7 Transport coefficients and cross sections for electrons in water vapour: Comparison of cross section sets using an improved Boltzmann equation solution PDF file J. Chem. Phys. 136, (2012); doi: / K. F. Ness, R. E. Robson, M. J. Brunger, and R. D. White This paper revisits the issues surrounding computation of electron transport properties in water vapour as a function of E/n0 in the range Td (1 Td = 1 townsend = 10 21Vm2). Various cross sections are incorporated into the Boltzmann equation rotational cross sections, total momentumtransfer cross sections, rotational differential cross Sections, vibrational processes, Five electronic-state excitation cross sections, dissociative attachment and ionization processes, electronic-state and ionization cross sections Uses Faure et al data. No explicit comment on rotational excitation 18 Rotational excitation of molecules by electron collisions PDF file Physics Reports 414 (2005) 1 41 Nigel to comment Yukikazu Itikawa, Nigel Mason reviewed electron induced rotational excitation. Detailed results of theoretical and experimental studies are presented cross sections ro tational

4 Rotational Excitation of H2O by Cold Electron Boltzmann equation analysis of electron molecule collision cross sections in water vapor and ammonia Electron-impact rotational excitation of water PDF file PRL 97, (2006) PDF file J. Appl. Phys. 80, 6619 (1996); doi: / PDF file Mon. Not. R. Astron. Soc. 347, (2004) R. Curık, J. P. Ziesel, N. C. Jones, T. A. Field, and D. Field M. Yousfi and M. D. Benabdes sadok Alexandre Faure,1 Jimena D. Gorfinkiel Experimental data are presented for the scattering of electrons by H2O between 17 and 250 mev impact energy. These results are used in conjunction with a generally applicable method, based on a quantum defect theory approach to electron-polar molecule collisions, to derive the first set of data for state-to-state rotationally inelastic scattering cross sections based on experimental values. Sets of electron-molecule collision cross sections for H2O and NH3 have been determined from a classical technique of electron swarm parameter unfolding. Rotational excitation of H2O, HDO and D2O by thermal rotationally inelastic scattering limited low-energy study, results consistent with Faure et al data. Rotational and vibrational excitation, Ionization and attachment cross sections, Elastic momentum transfer and total cross section Rather crude fit to Born (presumably Delta J =+/- 1) data Rotational, elastic Faure et al data, uses full asymmetric top selection rules, electron impact is studied using the molecular R-matrix method. considers DJ up to 4, HDO 2 and and D Jonathan 2 O. Available before last review. Use this instead? Tennyson 2

5 Elastic and rotational excitation crosssections for electronwater collisions in the lowand intermediateenergy ranges PDF file Eur. Phys. J. D 33, (2005) L.E. Machado, L.M. Brescansi n, I. Iga, and M.-T. calculated elastic differential, integral and momentum transfer cross-sections as well as rotational excitation cross- Goes to high energy (200 ev) sections in the (2 500)-eV range Reproduces Faure et al at low energy (I think) Lee Strongly peaked at about 15 ev, physical? Can be used for high energy extension if required Recommendation: Elastic, rotational Faure et al data seems reliable and should be updated to include full quantum numbers Include isotopologue data (HDO, D 2 O) Can use calculations of Machado et al to extend to higher energies if desired.

6 Vibrational excitation: previous recommendation (100)+(001) and (010) up to 5 ev only. Source various. Request for new experiment. 7 Transport coefficients and cross sections for electrons in water vapour: Comparison of cross section sets using an improved Boltzmann equation solution PDF file J. Chem. Phys. 136, (2012); doi: / K. F. Ness, R. E. Robson, M. J. Brunger, and R. D. White This paper revisits the issues surrounding computation of electron transport properties in water vapour as a function of E/n0 in the range Td (1 Td = 1 townsend = 10 21Vm2). Various cross sections are incorporated into the Boltzmann equation No explicit comment on vibrational excitation rotational cross sections, total momentumtransfer cross sections, rotational differential cross Sections, vibrational processes, Five electronic-state excitation cross sections, dissociative attachment and ionization processes, electronic-state and ionization cross sections T

7 12 37 Single electron tracks in water vapour for energies below 100 ev PDF file International Journal of Mass Spectrometry 277 (2008) Gustavo to comment Boltzmann equation analysis of electron molecule collision cross sections in water vapor and ammonia PDF file J. Appl. Phys. 80, 6619 (1996); doi: / A. Munoza, F. Blancob, G. Garcia, P.A. Thorn, M.J. Brunger, J.P. Sullivan, S.J. Buckman M. Yousfi and M. D. Benabdes sadok Electron cross sections in water experimental and theoretical electron interaction cross sections Sets of electron-molecule collision cross sections for H2O and NH3 have been determined from a classical technique of electron swarm parameter unfolding. Total electron scattering cross sections; Ionization cross sections; Electronic excitation cross sections; Vibrational excitation and electron attachment; inelastic scattering; inelastic cross sections both vibrational excitation and electron attachment Rotational and vibrational excitation, Ionization and attachment cross sections, Elastic momentum transfer and total cross section Reprocessing of old data available before last review Exp, theo ry theo ry

8 43 44 Vibrational excitation of water by lowenergy electron scattering: Calculations and experiments Individual fundamental mode dependence of H2O vibrational excitation in the 6 8 ev resonance region by electron impact PDF file Europhys. Lett., 65 (2), pp (2004) PDF file J. Chem. Phys. 122, (2005); doi: / T. Nishimura ( ) and F. A. Gianturco C. Makochek anwa, R. Kajita, H. Kato, M. Kitajima, H. Cho et al. Vibrationally inelastic crosssections of the water molecule by low-energy electron collisions are computed by solving the rigorous vibrational Fundamentals up coupled to channel 15 ev (VCC)equations within a body-fixed (BF)form Uses theory to separate (100) and (001) ulation. Should be considered Resonance phenomena in the bending ~010!, symmetric ~100!, and asymmetric ~001! stretching vibrational modes in water (H2O) molecules have been investigated by measuring differential cross sections ~DCSs! at fixed energy losses of 0.43, 0.46, 0.49, and 0.51 ev while sweeping the impact energies from 1.6 to 10 ev, at angles 60 and 90, using a crossed-beam method. Vibrational excitation theory Vibrational excitation Theory and exp Fixed angle study with full DCS at 7.5 ev 7.5 ev data may be useful

9 45 65 Collisional excitation of water in warm astrophysical media EPOTRAN: A fulldifferential Monte Carlo code for electron and positron transport in liquid and gaseous water PDF file A&A 492, (2008) A. Faure and E. Josselin new collisional rate coefficients for the (de)excitation of the lowest 824 ro-vibrational levels of water Use data from Gianturco and Nishimura PDF file International Journal of Radiation Biology, January February 2012; 88(1 2): Christoph e Champion, Cindy Le Loirec & Borko Stosic theoretical cross sections used in a special purpose Monte Carlo simulation suitable for electron and positron transport in gaseous and liquid water. Vibrational excitation theory Elastic scattering, Ionization, Excitation theory Recommendation: Update using Gianturco and Nishimura Requirement for new experiment remains

10 Inelastic: no papers not considered elsewhere (rotational, vibrational or electronic excitation) Recommendation: remove this heading from consideration Excitation of the a 3B1 and A 1B1 states of H2O by lowenergy electron impact PDF file J. Phys. B: At. Mol. Opt. Phys. 45 (2012) (6pp) L Hargreaves, K Ralphs, G Serna, M A Khakoo, CWinstead and V McKoy measured and calculated differential cross-sections for inelastic scattering of low-energy electrons by water leading to excitation of the dissociative (1b1 4a1) 1,3B1 states. The measurements were taken using conventional energy-loss spectroscopy at incident energies of 9, 10, 12, 15, and 20 ev for scattering angles from 10 to 130. The calculations were carried out using the Schwinger multichannel method, with a Borndipole correction applied in the singlet excitation channel. Integral excitation cross sections for the a 3B1 and A 1B1 states are also derived from the differential cross section results. inelastic Exp and theory scatterin g; excitation Single electron PDF file International A. Munoza, F. Electron cross sections in water Total Exp, theory

11 Electronscattering cross sections and stopping powers in H2O PDF file PHYSICAL REVIEW A 76, A. Muñoz, J. C. Oller, F. Blanco, J. D. Gorfinkiel, P. Limão- Vieira, and G. García Total electron-h2o scattering cross sections have been measured from 50 to 5000 ev with experimental errors of about 5%. ionization cross sections; total electron scatterin g cross section Integral elastic and inelastic cross sections Exp and theory

12 Total cross sections: this is really an experimental issue My recommendation: follow recommendations of Nigel and Gustavo! Other comments: I sent round a recent electron impact electronic excitation paper (expt and theory) I received from Morty Khakoo. The theoretical work by Haxton, Rescigno, McCurdy et al on DEA is state-of-the art and should be seriously considered for inclusion