TAILIEUCHUNG - Positron annihilation spectroscopy in material studies

Positron annihilation spectroscopy (PAS) is a method dedicated to detection of openvolume type of defects. Nowadays, this technique is of a great interest due to the practical character of obtained results. New devices using monoenergetic positron beams are built. The paper presents the basics of PAS, a description of common experimental techniques and two examples of applications. | Communications in Physics Vol. 29 No. 4 2019 pp. 501-510 DOI 0868-3166 29 4 14282 POSITRON ANNIHILATION SPECTROSCOPY IN MATERIAL STUDIES P. HORODEKa b f L. H. KHIEMc K. SIEMEKa b L. A. TUYENa d AND A. G. KOBETSa e a Joint Institute for Nuclear Research Joliot-Curie 6 141980 Dubna Moscow region Russia b Institute of Nuclear Physics PAN Radzikowskiego 152 31-342 Krakow Poland cInstitute of Physics VAST 18B Hoang Quoc Viet Street Cau Giay District Hanoi Vietnam d Center for Nuclear Techniques Vietnam Atomic Energy Institute 217 Nguyen Trai Ho Chi Minh City Vietnam eInstitute of Electrophysics and Radiation Technologies NAS of Ukraine 28 Chernyshevsky Str. 61002 Kharkov Ukraine E-mail Received 20 August 2019 Accepted for publication 11 September 2019 Published 23 October 2019 Abstract. Positron annihilation spectroscopy PAS is a method dedicated to detection of openvolume type of defects. Nowadays this technique is of a great interest due to the practical character of obtained results. New devices using monoenergetic positron beams are built. The paper presents the basics of PAS a description of common experimental techniques and two examples of applications. Keywords slow positron beam positron annihilation Doppler broadening of annihilation line positron lifetime. Classification numbers . z . 2019 Vietnam Academy of Science and Technology 502 POSITRON ANNIHILATION SPECTROSCOPY IN MATERIAL STUDIES I. INTRODUCTION One direction of material technology development is the study of nature of defects created in the materials. Theoretically a perfect structure in real world is never free from many kinds of imperfections which influence the material properties. Usually depending on size these defects are divided into points linears and planars. Linear defects dislocations and planar grain boundaries can be relatively easy to observe by means of electron microscopy. The method sensitive to the presence of point defects is .

• Vật lý
• Positron annihilation spectroscopy in material studies
• Positron annihilation spectroscopy
• Slow positron beam
• Doppler broadening of annihilation line
• Description of common experimental techniques
• The basics of PAS