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相关论文: Positron Annihilation Lifetime Spectroscopy Using …

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Single-shot time resolved Coherent Anti-Stokes Raman Scattering (CARS) is presented as a viable method for fast measurements of molecular spectra. The method is based on the short spatial extension of femtosecond pulses and maps time delays…

光学 · 物理学 2009-11-13 Yuri Paskover , I. Sh. Averbukh , Yehiam Prior

We present first-principles approaches based on density functional theory for calculating positron states and annihilation characteristics in condensed matter. The treatment of the electron-positron correlation effects (the enhancement of…

材料科学 · 物理学 2007-05-23 B. Barbiellini , M. Hakala , R. M. Nieminen , M. J. Puska

Density fluctuations in the ionised interstellar medium have a profound effect on radio pulsar observations, through angular scattering, intensity scintillations, and small changes in time delays from dispersion. Here we show that it is…

高能天体物理现象 · 物理学 2023-04-12 Daniel J. Reardon , William A. Coles

We make a gradient correction to a new local density approximation form of positron-electron correlation. Then the positron lifetimes and affinities are probed by using these two approximation forms based on three electronic-structure…

材料科学 · 物理学 2015-09-25 Wen-Shuai Zhang , Bing-Chuan Gu , Xiao-Xi Han , Jian-Dang Liu , Bang-Jiao Ye

Context. Interstellar scintillation (ISS) of pulsar emission can be used both as a probe of the ionised interstellar medium (IISM) and cause corruptions in pulsar timing experiments. Of particular interest are so-called scintillation arcs…

Proportional scintillation counters (PSCs), both single- and dual-phase, can measure the scintillation (S1) and ionization (S2) channels from particle interactions within the detector volume. The signal obtained from these detectors depends…

仪器与探测器 · 物理学 2016-03-23 Kareem Kazkaz , Tenzing Henry Yatish Joshi

Coincidence Doppler Broadening Spectroscopy (CDBS) of the 511 keV annihilation line reveals the elemental signature at the annihilation site in matter. For this reason, CDBS enables the analysis of foreign atoms in the host matrix,…

仪器与探测器 · 物理学 2023-03-02 Leon Chryssos , Christoph Hugenschmidt

In the context of particle therapy monitoring, we are developing a gamma-ray detector to determine the ion range in vivo from the measurement of particle time-of-flight. For this application, a beam monitor capable to tag in time the…

Introduction: Real-time dosimetry of surface doses in electron beams has not been widely established yet. Plastic scintillation detectors (PSD) promise high spatial resolution and real-time dosimetry with minimum perturbation of the…

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…

原子物理 · 物理学 2025-12-19 Lucas de Sousa Borges , Edward Thorpe-Woods , Evans Javary , Paolo Crivelli

Studies based on imaging the annihilation of the electron (e$^{-}$) and its antiparticle positron (e$^{+}$) open up several interesting applications in nuclear medicine and fundamental research. The annihilation process involves both the…

We propose a new method to detect off-pulse (unpulsed and/or continuous) emission from pulsars, using the intensity modulations associated with interstellar scintillation. Our technique involves obtaining the dynamic spectra, separately for…

高能天体物理现象 · 物理学 2018-05-23 Kumar Ravi , Avinash A. Deshpande

The objective of this work is to showcase the ortho-positronium lifetime as a probe for soft-tissue characterization. We employed positron annihilation lifetime spectroscopy to experimentally measure the three components of the positron…

Celestially, Positronium (Ps), has only been observed through gamma-ray emission produced by its annihilation. However, in its triplet state, a Ps atom has a mean lifetime long enough for electronic transitions to occur between quantum…

天体物理仪器与方法 · 物理学 2021-06-29 J. Gordon Robertson , Simon Ellis , Qingshan Yu , Joss Bland-Hawthorn , Christopher Betters , Martin Roth , Sergio Leon-Saval

Efforts are underway to magnetically confine electron--positron pair plasmas to study their unique behavior, which is characterized by significant changes in plasma time and length scales, supported waves, and unstable modes. However, use…

Incorrect choice of measuring geometry and signal discrimination thresholds for the BaF2 PAL spectrometer can lead to a significant distortion in the measured spectrum of positron lifetime. The contribution of the distorted events for…

仪器与探测器 · 物理学 2015-06-18 L. Yu. Dubov , V. I. Grafutin , Yu. V. Funtikov , Yu. V. Shtotsky , L. V. Elnikova

Accurate characterization of the asymmetry parameter g is of crucial importance for many radiative transfer and climate models. Here, we present our portable light scattering (PLS) device which is designed for in situ, real-time, and…

大气与海洋物理 · 物理学 2019-05-01 Yuli W. Heinson , Christopher M. Sorensen , Rajan K. Chakrabarty

A new experimental technique for investigating characteristics of plasma generated with plasmotrons in electrophysical installations was proposed. The technique involves a simultaneous registration of both radiation spectra and images of…

等离子体物理 · 物理学 2007-05-23 V. Yu. Khomich , I. I. Kumkova , Yu. A. Zheleznov

Lead halide perovskite nanocrystals (LHP-NCs) embedded in polymer matrices are gaining traction for next-generation radiation detectors. While progress has been made on green-emitting CsPbBr3 NCs, scant attention has been given to the…