6533b824fe1ef96bd128084b
RESEARCH PRODUCT
The slowing down times of positrons emitted from selected β+ isotopes into metals
Krzysztof SiemekP. HorodekJerzy Dryzeksubject
Nuclear and High Energy PhysicsEnd pointPositronIsotopeChemistryMonte Carlo methodAtomic numberAtomic physicsInstrumentationPositron annihilation spectroscopydescription
Abstract We report the GEANT4 Monte Carlo simulations and the approximated calculations of the slowing down time (SDT) for positrons emitted from three β+ isotopes, i.e., 22Na, 68Ge/68Ga and 48V. The first two isotopes are commonly used in the positron annihilation spectroscopy. The results revealed that the SDT exhibits the nonsymmetrical distribution and its average value depends on the end point energy of the isotope, the density and atomic number of the implanted material. For metals the average SDT varies from 0.4 ps to a few ps. We argue that this can affect the analysis of the measured positron lifetime and should be considered in theoretical calculations. The SDT in selected gases was simulated as well and in this case its average values are about four orders higher than in metals.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2012-11-01 | Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms |