The SPOT-IL Positron Beam Construction and Its Use for Doppler Broadening Measurement of Titanium Thin Films

TL;DR

This paper reports the construction and initial testing of a slow positron beam at Hebrew University, used for Doppler broadening measurements of titanium thin films, demonstrating consistent results with prior studies.

Contribution

It introduces a new positron beam setup with flexible detection options and demonstrates its application in characterizing titanium thin films.

Findings

Successful construction and operation of the positron beam.

Consistent Doppler broadening measurements of titanium films.

Flexible design allowing future detection enhancements.

Abstract

The construction and first operation of the slow positron beam built at the Hebrew University is reported here. The beam follows a traditional design, using a 22Na source, a Tungsten moderator, and a target cell equipped with a load-lock system for easy sample insertion. The beam energy varies between 0.03 keV and 30 keV. The detection system consists of two high purity Germanium detectors, facing each other, allowing low-background Doppler-Broadening (DB) measurements. Event readout is done using a state-of-the-art compact desktop system. The target cell is designed to allow a combined measurement of DB and sample conductivity, with the flexibility to add more detection options in the future. The beam has been successfully tested by using it to charecterize Titanium (Ti) films. Two 1.2 {\mu}m Ti films -- as produced, and after annealing, were measured at various energies (2 keV - 25 keV), and the results show consistent behavior with previous measurements.