Positron Annihilation with Electrons of Admixture Atoms in Some Binary Nickel Alloys

Weighted difference curves have been shortly presented as a proper tool allowing to analyze in another way two-detector Doppler spectra regarding positron annihilation with admixture electrons in some nickel alloys. The analysis of low and middle momentum parts of Doppler spectra for investigated alloys reflects the annihilation of positrons with admixture electrons. There is no distinct signal of annihilations with admixture electrons from the positron lifetime data for well-annealed samples.

A two-detector spectrometer for measurements of Doppler broadened positron annihilation spectra

Abstract A two-detector spectrometer for measurements of Doppler broadened positron annihilation spectra has been constructed and tested. The energy difference of the annihilation quanta is measured in the analogue, not in the digital manner. The peak to background ratio in the measured spectra is of the order of 10 6 , the FWHM representing the energy resolution, equals to 1.1 keV , thus enabling the very subtle physical effects to be revealed. Some information on electronic structure of the investigated 3-d metals (Ti, V, Cr, Fe, Ni, Cu and Zn) has been determined using this spectrometer. It has been shown that the apparatus permits to detect the impurity-vacancy pairs in dilute nickel al…

Test Measurements of Modernized Version of Two-Detector Doppler Spectrometer

The quality of the annihilation quanta energy measurements (Doppler effect) has greatly increased when experimenters have begun to introduce Doppler apparatus modifications. In the basic version, the experimental set-up consisted of high energy resolution Ge(Li) detector, amplifier and multichannel analyser. A simple construction and short time of data acquisition were the main advantages of that version of the apparatus. Competitive, angular correlation of annihilation radiation (ACAR) method was better from the resolution point of view and not worse when considering the range of momentum distribution, but the ACAR method required high activity positron sources and data acquisition time wa…

Studying of Nickel Alloys with 1 at.% of Ge, Zn, In, Zr and Pb by Positron Annihilation Methods