Total cross sections for electron scattering from molecules of applied interest PawełMożejko Atomic Physics Group Faculty of Applied Physics and Mathematics Gdańsk University of Technology Gdańsk, Poland
GdańskUniversity of Technology 1904 Köngliche Technische Hochschule zu Danzig ~0 students 1921 Technische Hochschule der Freien Stadt Danzig ~1600 students From 1945 Gdańsk Technical University Gdańsk University of Technology ~18 000 students
Electron scattering physics in Gdańsk Carl Ramsauer Ernst Brüche
FacultyofAppliedPhysicsand Mathematics
Atomic Physics Group at GUT Experiment: Prof. Czesław Szmytkowski Alicja Domaracka Grzegorz Kasperski Andrzej Krzysztofowicz Stanisław Kwitnewski Paweł Możejko Elżbieta Ptasińska-Denga Theory: Prof. Radosław Szmytkowski Sebastian Bielski Bożena Żywicka-Możejko Aleksander Miśta
Research activity Experiment: Total cross section measurements for electron scattering from atoms and molecules TCSs for almost 70 molecular targets have been measured He, Ne, Ar, Kr, Xe, H 2, N 2, O 2, CO, NO, CO 2, CS 2, H 2 O, D 2 O, NO 2, N 2 O, H 2 S, OCS, CH 3 Br, CH 3 Cl, CH 3 F, CH 3 I, CH 3 NH 2, CH 3 OH, CH 3 SH, C 2 H 4, C 2 H 6, C 3 H 4 (allene), C 3 H 4 (propyne) C 3 H 6, c-c 3 H 6, 1,3-C 4 H 6, 2-C 4 H 6, C 3 H 8, C 2 F 4, C 2 F 6, C 3 F 6, 1,3-C 4 F 6, 2-C 4 F 6, C 6 H 6, C 6 F 6, CH 4, CF 4, CCl 4, SiH 4, SiF 4, SiCl 4, GeH 4, GeF 4, GeCl 4, NH 3, NF 3, PH 3, PF 3, SF 4, SF 6, SO 2, SO 2 ClF, SO 2 Cl 2, Si 2 H 6, WF 6, BF 3, BCl 3, B(CD 3 ) 3, N(CH 3 ) 3, P(CH 3 ) 3, C 4 H 8 O, C 5 H 10 O 2 Simple model calculations Theory: Formal scattering theory Special functions in atomic physics
Experimental apparatus
Total cross section measurements experimental principles I0 IG P T I G (E)=I 0 (E)exp[ σ(e)nl] the projectile beam is monoenergetic, parallel and very narrow the concentration of target molecules, n, is low enough for interactions with projectiles to be single only only those projectiles are registered which have not interacted with target molecule the solid angle subtended by the detector is very near zero
Total cross section measurements experimental apparatus filament current 1-1.3 A magnetic field less than 0.1 µt background pressure 10 µpa pressure of the sample in the scattering volume 100 mpa electron beam energy 0.3-370 ev electron beam intensity 1-100 pa energy resolution ~ 50 mev
TCS for electron scattering from biologically relevant molecules 70 60 Total cross section [10 - m 2 ] 50 30 C 5 H 10 O 2 P. Możejko, A. Domaracka, E. Patsińska-Denga and Cz. Szmytkowski Chem. Phys. Lett. 429 (06) 378 C 4 H 8 O P. Możejko, E. Patsińska-Denga, A. Domaracka, Cz. Szmytkowski Phys. Rev. A 74 (06) 012708 1 10 100 600
TetrahydrofuranC 4 H 8 O Cross section [10 - m 2 ] 100 80 60 Experiment: P. Możejko, E. Ptasińska-Denga, A. Domaracka and Cz. Szmytkowski Phys. Rev. A 74 (06) 012708 A. Zecca, Ch. Perazzolli and M.J. Brugner J. Phys. B 38 (05) 79 Calculations: D. Bouchiha, J.D. Gornfinkiel, L. G. Caron and L. Sanche J. Phys. B 39 (06) 975 Total (elastic+inelastic), Total (elastic+inelastic) P. Możejko and L. Sanche. Radiat. Phys. Chem. 73 (05) 77 ionization, elastic, elastic+ionization Elastic: C. Winstead and V. McKoy J. Chem. Phys. 125 (06) 074302 S. Tonzani and Ch. Greene J. Chem. Phys. 125 (06) 094504 0 1 10 100 1000 00
α-tetrahydrofurfurylalcohol 70 60 Cross section [10 - m 2 ] 50 30 10 0 Experiment: P. Możejko, A. Domaracka, E. Ptasińska-Denga and Cz. Szmytkowski Chem. Phys. Lett. 429 (06) 378 Calculations: P. Możejko and L. Sanche. Radiat. Phys. Chem. 73 (05) 77 elastic ionization ionization + elastic A.R. Milosavljevic, F. Blanco, D. Sevic, G. Garcia and B.P. Marinkovic Eur. Phys. J. D (06) 107 elastic inelastic total 1 10 100 1000
TCS for molecules of environmental interest NO 2 15 NO 2 70 60 H 2 O Cross section [10 - m 2 ] 10 0 H 2 O Total cross section [10 - m 2 ] 10 5 0 a) 1 10 100 1000 50 30 10 0 b) 1 10 100 1000 10 0 10 100 1000 Szmytkowski and Możejko Optica App. 36(06) 542
TrimethylamineN(CH 3 ) 3 70 60 Total cross section [10 - m 2 ] 50 30 10 elastic total experimental ionization ionization+elastic N(CH 3 ) 3 0 1 10 100 1000 Szmytkowski, Domaracka, Możejko, Ptasińska-Denga Phys. Rev. A 75(07) 052721
Tetraherdralcompoundsofsilicon and germanium 80 70 60 50 30 10 0 GeCl 4 Szmytkowski, Możejko, Kasperski J. Phys. B 30 (1997) 4363 SiCl 4 Możejko, Kasperski, Szmytkowski, Zecca, Karwasz, Del Longo, Brusa Eur. Phys. J. D 6 (1999) 481 CCl 4 Szmytkowski, Krzysztofowicz, Janicki, Rosenthal Chem. Phys. Lett. 199 (1992) 191 1 10 100 XCl 4 (X = C, Si, F) Total cross section [10 - m 2 ] 80 GeH 4 Możejko, Kasperski, Szmytkowski J. Phys. B 29 (1996) L571 SiH 4 70 Szmytkowski, Możejko, Kasperski J. Phys. B 30 (1997) 4363 CH 4 Zecca, Karwasz, Brusa, Szmytkowski J. Phys. B 24 (1991) 2747 60 80 70 60 50 30 10 0 GeF 4 Szmytkowski, Możejko, Kasperski J. Phys. B 31 (1998) 3917 SiF 4 Karwasz, Brusa, Piazza, Zecca, Możejko, Szmytkowski Chem. Phys. Lett. 284 (1998) 128 CF 4 Szmytkowski, Krzysztofowicz, Janicki, Rosenthal Chem. Phys. Lett. 199 (1992) 191 1 10 100 XF 4 (X = C, Si, F) 50 30 10 0 1 10 100 XH 4 (X = C, Si, F)
Fluorination effect CF 4 45 C 3 H 6 C 3 F 6 SiF 4 GeF 4 Total cross section [10 - m 2 ] 35 30 25 15 10 C 3 H 6 Szmytkowski and Kwitnewski J. Phys. B 35 (02) 2613 C 3 F 6 Szmytkowski, Możejko, Kwitnewski J. Phys. B 35 (02) 1267 Szmytkowski, Kwitnewski, Możejko, Ptasińska-Denga Phys. Rev A 66 (02) 014701 SF 6 C 2 F 4 C 2 F 6 C 4 F 6 C 6 F 6 NF 3 1 10 100 PF 3 SF 4
Fluorination effect Total cross section [10 - m 2 ] 60 50 30 SF 6 Kasperski, Możejko, Szmytkowski Z. Phys. D 42 (1997) 187 WF 6 Szmytkowski, Możejko, Kasperski, Ptasińska-Denga J. Phys. B 33 (00) 15 C 2 F 6 Szmytkowski, Możejko, Kasperski, Ptasińska-Denga J. Phys. B 33 (00) 15 C 6 F 6 Kasperski, Możejko, Szmytkowski Z. Phys. D 42 (1997) 187 SF 6 WF 6 C 2 F 6 C 6 F 6 1 10 100
Isomeric effect 50 45 C 4 F 6 Total cross section [10 - m 2 ] 35 30 25 15 hexafluoro-2-butyne 1-3-butadiene Szmytkowski and Kwitnewski J. Phys. B 36 (03) 2129 J. Phys. B 36 (03) 4865 1 10 100
Simple model calculations Total cross section [10 - m 2 ] 80 70 60 50 30 10 0 50 P. Możejko, A. Domaracka, E. Patsińska-Denga and Cz. Szmytkowski Chem. Phys. Lett. 429 (06) 378 100 500 1000 Experiment: α-tetrahydrofurfuryl alcohol (C 5 H 10 O 2 ) Tetrahyfrofuran (C 4 H 8 O) Theoretical evaluation: Guanine Adenine Thymine Cytosine α-tetrahydrofurfuryl alcohol Uracil Tetrahyfrofuran σ BEB = σ tot σ elastic +σ ion σ elastic (E)= N σ i (E). i=1 S lnt 1 1t +1 1 t+u+1 2 2 t lnt, t+1 where,s=4πa 2 0NR 2 /B 2,u=U/B,t=T/B,a 0 =0.5292Å,R=13.61eV
Simple model calculations 60 Total cross section [10 - m 2 ] 55 50 45 35 30 25 Szmytkowski, Możejko, Krzysztofowicz 15 Radiat. Phys. Chem. 68 (03) 307 Szmytkowski, Możejko, Kwitnewski, Ptasińska-Denga, 10 A. Domaracka J. Phys. B 38 (06) 2945 5 Szmytkowski, Możejko, Kwitnewski, Domaracka, Ptasińska-Denga J. Phys. B 39 (06) 2571 0 8 1 10 100 1000 3000 SO 2 Cl 2 : exp. cal. SO 2 F 2 : cal. SO 2 FCl: exp. cal. SO 2 : exp. cal.
The Future electron collisions with condensed targets or the another object form our Guggenheim s collection credits Elżbieta Ptasińska-Denga
ESD from pure films of deutereted hydrocarbons Formation of the D - occurs via dissociative electron attachment and dipolar dissociation processes A single resonant maximum core excited resonances No desorbing heavier polyatomic ions were observed due to partitioning of the kinetic energy and isotope effects in production of negative ions. P. Możejko, L. Parenteau, A. D. Bass and L. Sanche, Radiat. Phys. Chem. 68, 215 (03)
Acknowledgments Czesław Szmytkowski Elżbieta Ptasińska-Denga Alicja Domaracka Grzegorz Kasperski Stanisław Kwitnewski This work is supported by the Polish Ministry of Science and Higher Education
Thank you!!!