Slow positron beam at the JINR, Dubna

Abstract

Na isotope is used. In distinction to popular tungsten foil, here the solid neon is used as moderator. It allows to obtain the beam intensity of about 10 5 e + /s width energy spectrum characterized by full width at half maximum (FWHM) of 3.4 eV and a tail to lower energies of about 30 eV. The paper covers the characteristic of variable energy positron beam at the LEPTA facility: parameters, the rule of moderation, scheme of injector, and transportation of positrons into the sample chamber. Recent status of the project and its development in the fi eld of PAS is discussed. As an example, the measurement of the positron diffusion length in pure iron is demonstrated.

Effect of Proton Irradiation on the Defect Evolution of Zr/Nb Nanoscale Multilayers

“…The defect-free reference, as well as the irradiated samples, were studied using the PAS method, Doppler broadening of the annihilation line (DBAL) using the variable positron energy at the JINR DLNP in Dubna, Russia [36,37]. A monoenergetic flux of positrons with a diameter of 5 mm with an intensity of 10 6 e + /s was used.…”

Positron Annihilation and Complementary Studies of Stainless Steel Exposed to Sandblasting at Different Angles

“…source. In the first case, slow positron beam working at Joint Institute for Nuclear Research in Dubna (Russia) was used [13]. The intensity of the flux was 10 6 e ?…”

Positron Beam Studies of Radiation Damage Induced by Various Energy Heavy Ions of Xe26+ in Iron

“…5, 6, and 8 µm for 45.5, 77, and 122.5 MeV Xe 26+ ions, respectively. The Doppler broadening (DB) spectra of studied samples were measured at room temperature using VEP at JINR [14]. The positrons formed in the 3 mm diameter flux with the intensity of 10 6 e + /s were implanted with incident energy range between 50 eV and 36 keV.…”