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Warianty tytułu
Konferencja
Polish Seminar on Positron Annihilation (42 nd ; 29.06-01.07.2016 ; Lublin, Poland)
Języki publikacji
Abstrakty
The Low Energy Positron Toroidal Accumulator (LEPTA) at the Joint Institute for Nuclear Research (JINR) proposed for generation of positronium in flight has been adopted for positron annihilation spectroscopy (PAS). The positron injector generates continuous slow positron beam with positron energy range between 50 eV and 35 keV. The radioactive 22Na isotope is used. In distinction to popular tungsten foil, here the solid neon is used as moderator. It allows to obtain the beam intensity of about 105 e+/s width energy spectrum characterized by full width at half maximum (FWHM) of 3.4 eV and a tail to lower energies of about 30 eV. The paper covers the characteristic of variable energy positron beam at the LEPTA facility: parameters, the rule of moderation, scheme of injector, and transportation of positrons into the sample chamber. Recent status of the project and its development in the field of PAS is discussed. As an example, the measurement of the positron diffusion length in pure iron is demonstrated.
Słowa kluczowe
Czasopismo
Rocznik
Strony
725--728
Opis fizyczny
Bibliogr. 12 poz., rys.
Twórcy
autor
- Joint Institute for Nuclear Research, 6 Joliot Curie Str., 141980 Dubna, Moscow region, Russian Federation
- Institute of Nuclear Physics of the Polish Academy of Sciences, 152 Radzikowskiego Str., 31-342 Kraków, Poland
autor
- Joint Institute for Nuclear Research, 6 Joliot Curie Str., 141980 Dubna, Moscow region, Russian Federation
- Institute of Electrophysics and Radiation Technologies NAS of Ukraine, 28 Chernyshevsky Str., 61002 Kharkov, Ukraine
autor
- Joint Institute for Nuclear Research, 6 Joliot Curie Str., 141980 Dubna, Moscow region, Russian Federation
autor
- Joint Institute for Nuclear Research, 6 Joliot Curie Str., 141980 Dubna, Moscow region, Russian Federation
autor
- Joint Institute for Nuclear Research, 6 Joliot Curie Str., 141980 Dubna, Moscow region, Russian Federation
Bibliografia
- 1. Sidorin, A., Meshkov, I., Akhmanova, E., Eseev, M., Kobets, A., Lokhmatov, V., Pavlov, V., Rudakov, A., & Yakovenko, S. (2013). The LEPTA facility for fundamental studies of positronium physics and positron spectroscopy. Mater. Sci. Forum, 733, 291–296. DOI: 10.4028/www.scientific.net/MSF.733.291.
- 2. Murphy, T. J., & Surko, C. M. (1992). Positron trapping in an electrostatic well by inelastic collisions with nitrogen molecules. Phys. Rev. A, 46, 5696–5705. DOI: 10.1103/PhysRevA.46.5696.
- 3. Puska, M. J., & Nieminen, R. M. (1994). Theory of positrons in solids and on solid surfaces. Rev. Mod. Phys., 66, 841–899. DOI: 10.1103/RevMod-Phys.66.841.
- 4. Krause-Rehberg, R., & Leipner, S. H. (1999). Positron annihilation in semiconductors: Defect studies. Berlin: Springer.
- 5. Dryzek, J. (2002). The solution of the time dependent positron diffusion equation valid for pulsed beam experiments. Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms, 196, 186–193. DOI: 10.1016/S0168-583X(02)01253-3.
- 6. Dryzek, J., & Horodek, P. (2008). GEANT4 simulation of slow positron beam implantation profiles. Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms, 266(18), 4000–4009. DOI: 10.1016/j.nimb.2008.06.033.
- 7. Schultz, P. J., & Lynn, K. G. (1988). Interaction of positron beams with surfaces, thin films and interfaces. Rev. Mod. Phys., 60, 701–779. DOI: 10.1103/RevModPhys.60.701.
- 8. Iwai, T., Schut, H., Ito, Y., & Koshimizu, M. (2004). Vacancy-type defect production in iron under ion beam irradiation investigated with positron beam Doppler broadening technique. J. Nucl. Mater., 329/333, 963–966. DOI: 10.1016/j.jnucmat.2004.04.064.
- 9. He, C. W., Dawi, K., Platteau, C., Barthe, M. F., Desgardin, P., & Akhmadaliev, S. (2014). Vacancy type defect formation in irradiated α-iron investigated by positron beam Doppler broadening technique. J. Phys. Conf. Ser., 505, 012018. DOI: 10.1088/1742-6596/505/1/012018.
- 10. Van Veen, A., Schut, H., Clement, M., Kruseman, A., Ijpma, M. R., & De Nijs, J. M. M. (1995). VEPFIT applied to depth profiling problems. Appl. Surf. Sci., 85, 216–224. DOI: 10.1016/0169-4332(94)00334-3.
- 11. Paulin, R., Ripon, R., & Brandt, W. (1974). Diffusion constant and surface states of positrons in metals. Appl. Phys., 4, 343–347. DOI: 10.1007/BF00928390.
- 12. Lukáč, F., Čižek, J., Procházka, I., Jirásková, Y., Janičkovič, D., Anwand, W., & Brauer, G. (2013).Vacancy-induced hardening in Fe-Al alloys. J. Phys. Conf. Ser., 443, 012025. DOI: 10.1088/1742-6596/443/1/012025.
Typ dokumentu
Bibliografia
Identyfikator YADDA
bwmeta1.element.baztech-f2a7308a-cc13-43d0-9cb8-393ca2925c9d