Results 81 to 90 of about 55,721 (192)

Stringent Constraint on Galactic Positron Production

, 2006
The intense 0.511 MeV gamma-ray line emission from the Galactic Center observed by INTEGRAL requires a large annihilation rate of nonrelativistic positrons.
A. W. Strong, F. A. Agaronyan, F. A. Aharonian, F. A. Aharonian, Hasan Yüksel, I. V. Moskalenko, J. Knödlseder, John F. Beacom, M. Signore, M. S. Longair, P. A. M. Dirac, W. Heitler   +11 more
core   +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

Hadronic footprint of GeV-mass dark matter

SciPost Physics, 2020
GeV-scale dark matter is an increasingly attractive target for direct detection, indirect detection, and collider searches. Its annihilation into hadronic final states produces a challenging zoo of light hadronic resonances. We update Herwig7 to study
Tilman Plehn, Peter Reimitz, Peter Richardson
doaj   +1 more source

From polymer to SiOC glass: structure, microstructure, mechanical, and thermal properties

Journal of the American Ceramic Society, Volume 108, Issue 12, December 2025.
Abstract The transformation of a methyl‐siloxane into a SiOC glass in Ar and reactive CO2 atmosphere was studied through positron annihilation spectroscopy, infrared spectroscopy, density, and calorimetric measurements, whereas the mechanical properties were monitored by nanoindentation and the thermal diffusivity measured by the laser flash method ...
Mattia Biesuz, Adane M. Abebe, Levent Karacasulu, Sebastiano Mariazzi, Roberto S. Brusa, Daria Szewczyk, Nicola Pugno, Giacomo Sero, Maik Butterling, Maciej Oskar Liedke, Andreas Wagner, Eric Hirschmann, Michele Cassetta, Gian D. Sorarù   +13 more
wiley   +1 more source

Positron trapping and annihilation at interfaces between matrix and cylindrical or spherical precipitates modeled by diffusion-reaction theory

, 2019
The exact solution of a diffusion$-$reaction model for the trapping and annihilation of positrons at interfaces of precipitate$-$matrix composites is presented considering both cylindrical or spherical precipitates.
Klinser, Gregor, Resch, Laura, Würschum, Roland   +2 more
core   +1 more source

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

Proposition of Hyper‐Chemical Exchange Saturation Transfer Subtraction Spectroscopy to Detect Very Weak and Broad Signals Hidden Under Baseline and Widen Range of Materials Accessed by Hyperpolarized 129Xe NMR

ChemPhysChem, Volume 26, Issue 23, November 28, 2025.
A polyimide sample, for which hyperpolarized 129Xe NMR spectroscopy failed to detect 129Xe embedded in the polymer (Inset A), is found to give a very broad peak, line width 11 kHz at 206.5 ppm, by applying the stopped‐flow hyper‐chemical exchange saturation transfer subtraction spectroscopy on the continuous‐flow recirculating hyper‐polarization system
Hideaki Fujiwara, Hirohiko Imai, Atsuomi Kimura   +2 more
wiley   +1 more source

Gamma-Rays from Positron Annihilation

, 2009
SPI on INTEGRAL has provided spectra and a map of the sky in the emission from annihilations of positrons in the interstellar medium of our Galaxy.
Diehl, Roland, Leising, Mark
core   +1 more source

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

Effect of Ultra‐High‐Pressure Annealing on Defect Reactions in Ion‐Implanted GaN Studied by Positron Annihilation [PDF]

, 2022
Akira Uedono, Hideki Sakurai, Jun Uzuhashi, Tetsuo Narita, Kacper Sierakowski, Shoji Ishibashi, Shigefusa F. Chichibu, Michał Boćkowski, Jun Suda, Tadakatsu Ohkubo, Nobuyuki Ikarashi, K. Hono, Tetsu Kachi   +12 more
openalex   +1 more source