Total cross sections for electron scattering from molecules of applied interest

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1 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

2 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 ~ students

3 Electron scattering physics in Gdańsk Carl Ramsauer Ernst Brüche

4 FacultyofAppliedPhysicsand Mathematics

5 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

6 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

7 Experimental apparatus

8 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

9 Total cross section measurements experimental apparatus filament current 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 ev electron beam intensity pa energy resolution ~ 50 mev

10 TCS for electron scattering from biologically relevant molecules Total cross section [10 - m 2 ] 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)

11 TetrahydrofuranC 4 H 8 O Cross section [10 - m 2 ] Experiment: P. Możejko, E. Ptasińska-Denga, A. Domaracka and Cz. Szmytkowski Phys. Rev. A 74 (06) 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) S. Tonzani and Ch. Greene J. Chem. Phys. 125 (06)

12 α-tetrahydrofurfurylalcohol Cross section [10 - m 2 ] 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

13 TCS for molecules of environmental interest NO 2 15 NO H 2 O Cross section [10 - m 2 ] 10 0 H 2 O Total cross section [10 - m 2 ] a) b) Szmytkowski and Możejko Optica App. 36(06) 542

14 TrimethylamineN(CH 3 ) Total cross section [10 - m 2 ] elastic total experimental ionization ionization+elastic N(CH 3 ) Szmytkowski, Domaracka, Możejko, Ptasińska-Denga Phys. Rev. A 75(07)

15 Tetraherdralcompoundsofsilicon and germanium 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) 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) 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) XF 4 (X = C, Si, F) XH 4 (X = C, Si, F)

16 Fluorination effect CF 4 45 C 3 H 6 C 3 F 6 SiF 4 GeF 4 Total cross section [10 - m 2 ] 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) SF 6 C 2 F 4 C 2 F 6 C 4 F 6 C 6 F 6 NF PF 3 SF 4

17 Fluorination effect Total cross section [10 - m 2 ] 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

18 Isomeric effect C 4 F 6 Total cross section [10 - m 2 ] hexafluoro-2-butyne 1-3-butadiene Szmytkowski and Kwitnewski J. Phys. B 36 (03) 2129 J. Phys. B 36 (03)

19 Simple model calculations Total cross section [10 - m 2 ] P. Możejko, A. Domaracka, E. Patsińska-Denga and Cz. Szmytkowski Chem. Phys. Lett. 429 (06) 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 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

20 Simple model calculations 60 Total cross section [10 - m 2 ] Szmytkowski, Możejko, Krzysztofowicz 15 Radiat. Phys. Chem. 68 (03) 307 Szmytkowski, Możejko, Kwitnewski, Ptasińska-Denga, 10 A. Domaracka J. Phys. B 38 (06) Szmytkowski, Możejko, Kwitnewski, Domaracka, Ptasińska-Denga J. Phys. B 39 (06) SO 2 Cl 2 : exp. cal. SO 2 F 2 : cal. SO 2 FCl: exp. cal. SO 2 : exp. cal.

21 The Future electron collisions with condensed targets or the another object form our Guggenheim s collection credits Elżbieta Ptasińska-Denga

22 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)

23 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

24 Thank you!!!