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Related papers: Positronium Imaging: History, Current Status, and …

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We present a calculation of the branching ratio of orthopositronium decay into an invisible mode, which is done in the context of Mirror World models, where ordinary positronium can disappear from our world due to oscillation into its…

High Energy Physics - Phenomenology · Physics 2013-05-30 S. V. Demidov , D. S. Gorbunov , A. A. Tokareva

We report a 4.9\,ppb measurement of the positronium $\text{1}^\text{3}\text{S}_\text{1} \to \text{2}^\text{3}\text{S}_\text{1}$ interval using continuous-wave two-photon laser spectroscopy. The transition is detected via photoionization by…

Atomic Physics · Physics 2025-12-19 Lucas de Sousa Borges , Edward Thorpe-Woods , Evans Javary , Paolo Crivelli

Current tomographic imaging systems need major improvements, especially when multi-dimensional, multi-scale, multi-temporal and multi-parametric phenomena are under investigation. Both preclinical and clinical imaging now depend on in vivo…

Omni-tomography is enabled by interior tomography that has been developed over the past five years. By omni-tomography, we envision that the next stage of biomedical imaging will be the grand fusion of many tomographic modalities into a…

Medical Physics · Physics 2012-12-24 Ge Wang , Yue Wang , Michael W. Vannier

Para positronium composed by an electron-antielectron pair is an unstable system decaying into two high energetic gamma photons via self annihilation process, due to the conservation of the charge conjugation parity in electromagnetically…

Quantum Physics · Physics 2019-08-23 Abdullah Guvendi , Yusuf Sucu

The integration of positron emission tomography (PET) and magnetic resonance imaging (MRI) has been an ongoing research topic for the last 20 years. This paper gives an overview of the different developments and the technical problems…

Medical Physics · Physics 2015-10-19 Stefaan Vandenberghe , Paul Marsden

Positron emission tomography (PET) is a medical imaging method based on the measurement of concentrations of positron-emitting radionuclides in a living body. In the PET imaging system, glucose is labeled with a positron-emitting…

Signal Processing · Electrical Eng. & Systems 2022-09-27 Mehmet Akif Ozdemir , Ali Tangel

Proton therapy is nowadays becoming a wide spread clinical practice in cancer therapy and sophisticated treatment planning systems are routinely used to exploit at best the ballistic properties of charged particles. The information on the…

Medical Physics · Physics 2015-05-14 S. Braccini , A. Ereditato , I. Kreslo , U. Moser , C. Pistillo , P. Scampoli , S. Studer

The positronium molecule (Ps$_2$) has not been experimentally observed yet because its tiny (4.5 eV) binding energy cannot be detected when the molecule annihilates by emitting two photons with energy of 0.51 MeV each. It is shown in this…

Atomic Physics · Physics 2009-10-31 J. Usukura , K. Varga , Y. Suzuki

This work reports on a new reconstruction algorithm allowing to reconstruct the decays of ortho-positronium atoms into three photons using the places and times of photons recorded in the detector. The method is based on trilateration and…

Carbon ion therapy have the ability to overcome the limitation of convertional radiotherapy due to its most energy deposition in selective depth, usually called Bragg peak, which results in increased biological effectiness. During carbon…

Here we describe an advanced multi functional, variable-energy positron beam system capable of measuring the energies of multiple positron-induced electrons in coincidence with the Doppler-shifted gamma photon resulting from the…

Rates of the two-, three-, four- and five-photon annihilations of the electron-positron pairs are determined numerically for the three-body positronium ion Ps$^-$ ($e^- e^+ e^-$) and four-body bi-positronium `molecule' Ps$_2$ ($e^- e^+ e^-…

High Energy Physics - Phenomenology · Physics 2015-05-13 Alexei M. Frolov

Positron scattering and annihilation on noble gas atoms below the positronium formation threshold is studied ab initio using many-body theory methods. The many-body theory provides a near-complete understanding of the…

Atomic Physics · Physics 2014-09-12 D. G. Green , J. A. Ludlow , G. F. Gribakin

In state-of-the-art Positron Emission Tomography (PET), information about annihilation photon polarization is unavailable. Here, we present a PET scanner built from plastic scintillators, where annihilation photons primarily interact via…

Currently, the experimental uncertainty for the determination of the ortho-positronium (o-Ps) decay rate is at 150 ppm precision; this is two orders of magnitude lower than the theoretical one, at 1 ppm level. Here we propose a new proof of…

Atomic Physics · Physics 2022-01-26 C. Vigo , M. Raajimakers , L. Gerchow , B. Radics , A. Rubbia , P. Crivelli

Particle beams focused to micrometer-sized spots play a crucial role in forefront research using low-energy positrons. Their expedient and wide application, however, requires highly-resolved, fast beam diagnostics. We have developed two…

In this article, we present an up-to-date overview of the potential biomedical applications of sodium MRI in vivo. Sodium MRI is a subject of increasing interest in translational research as it can give some direct and quantitative…

Medical Physics · Physics 2012-12-21 Guillaume Madelin

We discuss the possibility to perform the experimental searches of invisible decays in the ortho-positronium system with the J-PET detector

Instrumentation and Detectors · Physics 2020-01-20 W. Krzemien , E. Perez del Rio , Krzysztof Kacprzak

Novel Positron Emission Tomography system, based on plastic scintillators, is developed by the J-PET collaboration. In order to optimize geometrical configuration of built device, advanced computer simulations are performed. Detailed study…

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