RUPAC2012 - List of Authors (Horodek, P.)

Paper	Title	Page
WEPPC044	Positron Annihilation Spectroscopy at LEPTA Facility	532
	P. Horodek, I.N. Meshkov JINR/DLNP, Dubna, Moscow region, Russia A.G. Kobets, V.I. Lokhmatov, V. Pavlov, A.Yu. Rudakov, A.A. Sidorin, S. Yakovenko JINR, Dubna, Moscow Region, Russia
	The Low Energy Positron Toroidal Accumulator (LEPTA) at JINR proposed for generation of positronium in flight can be used for positron annihilation spectroscopy (PAS). The positron injector of the LEPTA facility can generate continuous slow positron beam of the intensity up to 1*10⁷ s⁻¹ at the energy in the range of a few eV to 100 keV and width of the spectrum 1-2 eV. The injector is based on radioactive 22Na isotope. The solid neon is used as moderator to generate monochromatic positron beam. It is known that positrons implanted into the matter can localize the defects of structure as vacancies, clusters of vacancies and pores. Observation of gamma quanta (511 keV) from annihilation process allows to obtain the information about the presence, concentration and kind of defects. Nowadays, the experiments with the use of slow positrons beam instead of standard isotopic sources are more popular. The progress in the creation of Doppler broadening of annihilation gamma line spectrometer will be presented here. In the simplest version, it is a set composed of a HpGe detector, a preampliefier, an ampliefier, a MC analyzer and a PC computer. This combination makes possible the observation of changes in 511 keV gamma line, calculation characteristics for PAS parameters and in effect to deduce about defects concentration and their chemical surrounding.

Paper

Title

Page

Positron Annihilation Spectroscopy at LEPTA Facility

532

P. Horodek, I.N. Meshkov
JINR/DLNP, Dubna, Moscow region, Russia
A.G. Kobets, V.I. Lokhmatov, V. Pavlov, A.Yu. Rudakov, A.A. Sidorin, S. Yakovenko
JINR, Dubna, Moscow Region, Russia

The Low Energy Positron Toroidal Accumulator (LEPTA) at JINR proposed for generation of positronium in flight can be used for positron annihilation spectroscopy (PAS). The positron injector of the LEPTA facility can generate continuous slow positron beam of the intensity up to 1*10⁷ s⁻¹ at the energy in the range of a few eV to 100 keV and width of the spectrum 1-2 eV. The injector is based on radioactive 22Na isotope. The solid neon is used as moderator to generate monochromatic positron beam. It is known that positrons implanted into the matter can localize the defects of structure as vacancies, clusters of vacancies and pores. Observation of gamma quanta (511 keV) from annihilation process allows to obtain the information about the presence, concentration and kind of defects. Nowadays, the experiments with the use of slow positrons beam instead of standard isotopic sources are more popular. The progress in the creation of Doppler broadening of annihilation gamma line spectrometer will be presented here. In the simplest version, it is a set composed of a HpGe detector, a preampliefier, an ampliefier, a MC analyzer and a PC computer. This combination makes possible the observation of changes in 511 keV gamma line, calculation characteristics for PAS parameters and in effect to deduce about defects concentration and their chemical surrounding.