Energy loss of protons in W using fully relativistic calculations and mean excitation energies of W, Au, Pb, and Bi
We present a theoretical study on the energy loss of protons in wolframium by calculating target fully relativistic wave functions and binding energies. The HULLAC code is employed to obtain numerical solutions of the Dirac equation. We use the shellwise local plasma approximation (SLPA) to evaluate...
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2009
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paper:paper_10502947_v80_n1_p_Montanari2023-06-08T16:02:32Z Energy loss of protons in W using fully relativistic calculations and mean excitation energies of W, Au, Pb, and Bi Montanari, Claudia Carmen Mitnik, Dario Marcelo Archubi, Claudio Dario Miraglia, Jorge Esteban 4f-electrons Cross section Dirac equations Energy loss Energy regions Experimental data Fully relativistic calculations Impact energy Mean excitation energy Numerical solution Subshells Target electrons Theoretical study Very high energies Binding sites Electron energy loss spectroscopy Electrons Energy dissipation Excitation energy Lead Lead alloys Linear equations Nuclear energy Potential energy Protons Tungsten Wave functions Binding energy We present a theoretical study on the energy loss of protons in wolframium by calculating target fully relativistic wave functions and binding energies. The HULLAC code is employed to obtain numerical solutions of the Dirac equation. We use the shellwise local plasma approximation (SLPA) to evaluate the different moments of the energy loss. The partial contribution of each subshell of target electrons is calculated separately, including the screening among the electrons of the same binding energy. We pay special attention to the role of the outer 4f shell and the screening between electrons of near subshells (i.e., the 5p and 4f electrons). Results for stopping and straggling cross sections are compared to the experimental data available. Our calculations describe rather well the stopping measurements around the maximum and for very high energies, but overestimate the data for impact energies around 1MeV. We find that the SLPA results tend clearly to Bethe limit, but show a systematic overestimation in the energy region of 1-2 MeV. This overestimation may indicate the presence of other mechanisms included neither in the SLPA nor in Bethe formulations. We also present results for the stopping number of W, Au, Pb, and Bi which follow quite well the Lindhard scaling. A theoretical mean excitation energy I (W) =710eV is obtained, in good agreement with the suggested value of 727±30eV. Theoretical mean excitation energies for Au, Pb, and Bi are also presented, which are in good agreement with the experimental ones. © 2009 The American Physical Society. Fil:Montanari, C.C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Mitnik, D.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Archubi, C.D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Miraglia, J.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2009 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_10502947_v80_n1_p_Montanari http://hdl.handle.net/20.500.12110/paper_10502947_v80_n1_p_Montanari |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
4f-electrons Cross section Dirac equations Energy loss Energy regions Experimental data Fully relativistic calculations Impact energy Mean excitation energy Numerical solution Subshells Target electrons Theoretical study Very high energies Binding sites Electron energy loss spectroscopy Electrons Energy dissipation Excitation energy Lead Lead alloys Linear equations Nuclear energy Potential energy Protons Tungsten Wave functions Binding energy |
| spellingShingle |
4f-electrons Cross section Dirac equations Energy loss Energy regions Experimental data Fully relativistic calculations Impact energy Mean excitation energy Numerical solution Subshells Target electrons Theoretical study Very high energies Binding sites Electron energy loss spectroscopy Electrons Energy dissipation Excitation energy Lead Lead alloys Linear equations Nuclear energy Potential energy Protons Tungsten Wave functions Binding energy Montanari, Claudia Carmen Mitnik, Dario Marcelo Archubi, Claudio Dario Miraglia, Jorge Esteban Energy loss of protons in W using fully relativistic calculations and mean excitation energies of W, Au, Pb, and Bi |
| topic_facet |
4f-electrons Cross section Dirac equations Energy loss Energy regions Experimental data Fully relativistic calculations Impact energy Mean excitation energy Numerical solution Subshells Target electrons Theoretical study Very high energies Binding sites Electron energy loss spectroscopy Electrons Energy dissipation Excitation energy Lead Lead alloys Linear equations Nuclear energy Potential energy Protons Tungsten Wave functions Binding energy |
| description |
We present a theoretical study on the energy loss of protons in wolframium by calculating target fully relativistic wave functions and binding energies. The HULLAC code is employed to obtain numerical solutions of the Dirac equation. We use the shellwise local plasma approximation (SLPA) to evaluate the different moments of the energy loss. The partial contribution of each subshell of target electrons is calculated separately, including the screening among the electrons of the same binding energy. We pay special attention to the role of the outer 4f shell and the screening between electrons of near subshells (i.e., the 5p and 4f electrons). Results for stopping and straggling cross sections are compared to the experimental data available. Our calculations describe rather well the stopping measurements around the maximum and for very high energies, but overestimate the data for impact energies around 1MeV. We find that the SLPA results tend clearly to Bethe limit, but show a systematic overestimation in the energy region of 1-2 MeV. This overestimation may indicate the presence of other mechanisms included neither in the SLPA nor in Bethe formulations. We also present results for the stopping number of W, Au, Pb, and Bi which follow quite well the Lindhard scaling. A theoretical mean excitation energy I (W) =710eV is obtained, in good agreement with the suggested value of 727±30eV. Theoretical mean excitation energies for Au, Pb, and Bi are also presented, which are in good agreement with the experimental ones. © 2009 The American Physical Society. |
| author |
Montanari, Claudia Carmen Mitnik, Dario Marcelo Archubi, Claudio Dario Miraglia, Jorge Esteban |
| author_facet |
Montanari, Claudia Carmen Mitnik, Dario Marcelo Archubi, Claudio Dario Miraglia, Jorge Esteban |
| author_sort |
Montanari, Claudia Carmen |
| title |
Energy loss of protons in W using fully relativistic calculations and mean excitation energies of W, Au, Pb, and Bi |
| title_short |
Energy loss of protons in W using fully relativistic calculations and mean excitation energies of W, Au, Pb, and Bi |
| title_full |
Energy loss of protons in W using fully relativistic calculations and mean excitation energies of W, Au, Pb, and Bi |
| title_fullStr |
Energy loss of protons in W using fully relativistic calculations and mean excitation energies of W, Au, Pb, and Bi |
| title_full_unstemmed |
Energy loss of protons in W using fully relativistic calculations and mean excitation energies of W, Au, Pb, and Bi |
| title_sort |
energy loss of protons in w using fully relativistic calculations and mean excitation energies of w, au, pb, and bi |
| publishDate |
2009 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_10502947_v80_n1_p_Montanari http://hdl.handle.net/20.500.12110/paper_10502947_v80_n1_p_Montanari |
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