Kinetic energy of Ps formed by Ore mechanism in Ar gas

11th International Workshop on Positron and Positronium Chemistry

物理学;化学

Sano, Yosuke^1 ; Kino, Yasushi^1 ; Oka, Toshitaka^1,2 ; Sekine, Tsutomu^2

Department of Chemistry, Tohoku University, Sendai

980-8578, Japan^1

Center for the Advancement of Higher Education, Tohoku University, Sendai

980-8576, Japan^2

关键词: Age-momentum correlation;    Initial kinetics;    Momentum transfer cross sections;    Self annihilation;    Theoretical calculations;    Time dependence;    Upper limits;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/618/1/012010/pdf
DOI  :  10.1088/1742-6596/618/1/012010

来源: IOP

【 摘 要 】

In order to investigate kinetic energy of positronium(Ps) formed by Ore mechanism, we performed positron annihilation age-momentum correlation (AMOC) measurements in Argas for 5.0 MPa and 7.5 MPa at room temperature. From the time dependence of Doppler broadening of para-Ps (p-Ps) self-annihilation gramma-ray component, we observed Ps slowing down process. Using a simple slowing down model, we obtained the initial kinetic energy of Ps formed by Ore mechanism and Ps-Armomentum transfer cross section. The initial kinetic energy was 3.9 eV which was higher than the kinetic energy of Ps formed at the upper limit of Ore gap. The momentum transfer cross section was 0.019 ± 0.010 nm2in between 1 eV and 3.9 eV, and was close to the theoretical calculation.