Results 81 to 90 of about 144,387 (227)

Fast high-resolution lifetime image reconstruction for positron lifetime tomography

Communications Physics
Due to the ortho-positronium formed prior to the annihilation, the lifetime of a positron is sensitive to the tissue microenvironment and can potentially provide valuable information for monitoring disease progression and treatment response. However, the
Bangyan Huang, Zipai Wang, Xinjie Zeng, Amir H. Goldan, Jinyi Qi   +4 more
doaj   +1 more source

A study of vacancy defects related to gray tracks in KTiOPO4 (KTP) using positron annihilation

AIP Advances, 2014
For the first time to our knowledge, positron annihilation spectroscopy (PAS) was used to study vacancy defects in KTiOPO4 (KTP) single crystals. Positron annihilation lifetime spectroscopy combined with dielectric measurements identified the existence ...
Yang Zhang, Jing Li, Xingzhong Cao, Jing Yang, Jiyang Wang, Huaidong Jiang   +5 more
doaj   +1 more source

Surfaces of colloidal PbSe nanocrystals probed by thin-film positron annihilation spectroscopy

APL Materials, 2013
Positron annihilation lifetime spectroscopy and positron-electron momentum density (PEMD) studies on multilayers of PbSe nanocrystals (NCs), supported by transmission electron microscopy, show that positrons are strongly trapped at NC surfaces, where ...
L. Chai, W. Al-Sawai, Y. Gao, A. J. Houtepen, P. E. Mijnarends, B. Barbiellini, H. Schut, L. C. van Schaarenburg, M. A. van Huis, L. Ravelli, W. Egger, S. Kaprzyk, A. Bansil, S. W. H. Eijt   +13 more
doaj   +1 more source

Design and Implementation of a Digital Positron Annihilation Lifetime Spectrometer for Measurements in Graphite

, 2009
A digital Positron Annihilation Lifetime Spectrometer was designed and used to perform measurements on three graphite materials, reactor grade graphite, pyrolytic graphite, and a foam graphite developed by Oak Ridge National Laboratory.
Bodnaruk, Ethan Wesley
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Positron-annihilation study of compensation defects in InP

, 2002
Positron-annihilation lifetime and positron-annihilation Doppler-broadening (PADB) spectroscopies have been employed to investigate the formation of vacancy-type compensation defects in n-type undoped liquid encapsulated Czochrolski grown InP, which ...
Zhao YW, Deng AH, Shan YY, Ling CD, Ling CC, Sun NF, Sun TN, Fung S, Shan YY,Univ Hong Kong,Dept Phys,Hong Kong,Hong Kong,Peoples R China.   +8 more
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Surface areas by positron annihilation spectroscopy [PDF]

, 1985
Positron annihilation spectroscopy (PAS) is a technique for measuring the length of time that a positron exists after being injected into a specific material. Lifetime measurements have been used for studying defects in metals. These imperfections affect
Dale, J.M., Rosseel, T.M., Fuller, E.L., Jean, Y.C., Hulett, L.D., Venkateswaran, K.   +5 more
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Positron annihilation in Ni3Al: Theory and experiment

, 2001
SCOPUS: cp.kinfo:eu-repo/semantics ...
Mondelaers, Willy, MORALES, AL, Mondelaers, WillyWE05801000965411F4D226A0-F0ED-11E1-A9DE-61C894A0A6B4, Kuriplach, Jan, Van Petegem, Steven, Hou, Marc, ETTAOUSSI, S, Segers, DannyUGent801000311972976452731707F3A9AF82-F0ED-11E1-A9DE-61C894A0A6B4, Zhurkin, Evgeny, Dauwe, Ch, KURIPLACH, J, ZHURKIN, EE, Ettaoussi, S., Mondelaers, Wim, HOU, M, Dauwe, CharlesUGent801000274889974245653321F38A953E-F0ED-11E1-A9DE-61C894A0A6B4, VAN PETEGEM, S, Dauwe, Charles, Segers, Danny, Morales, A.L.   +19 more
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Positron Annihilation Spectroscopy of Active Galactic Nuclei

Journal of Astronomy and Space Sciences, 2019
A regular and random components in the fluxes of quanta and particles from AGN is investigated. We consider the diffuse component and detect radiative feedback after the passage of cosmic rays and quanta through AGN.
Alexander V. Yushchenko, Yeuncheol Jeong   +1 more
doaj   +1 more source

Thermal isomerization of azo-benzene in PMMA probed by a pulsed low-energy positron beam

, 2004
Polymers containing the Azo-benzene group have attracted attention due to anticipated uses such as materials for data storage, membranes with controllable permeability and materials with changeable solubility [1,2].
Egger, W, Skeppstedt, V, Algers, John,, Sperr, P, Maurer, Frans,, Lund University.   +5 more
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On the annihilation radiation of positrons [PDF]

Proceedings of the Royal Society of London. Series A - Mathematical and Physical Sciences, 1935
Abstract The annihilation of positrons may occur either (1) when the positron is in motion, or (2) when it has already been stopped. In the first case, which will be discussed in this paper, either one or two quanta may be emitted. The two-quanta annihilation, which was first considered by Dirac, may occur between any free or bound ...
openaire   +2 more sources