A slow positron facility is being built in Israel, at the Hebrew University, for basic and applied research. It consists of a slow positron beam and a compact Positrons Annihilation Lifetime (PAL) spectrometer. The slow positron beam follows a traditional design, using a 22Na source, of about 40mCi, a Tungsten moderator and a unique grounded target cell, with positrons energy that can vary between 0.03 keV and 30 keV. The detection system will be comprised of High Purity Germanium and BaF2 detectors, facing each other, for low background Doppler Broadening (DB) measurements. The target cell is designed to allow a combined measurement of sample conductivity and DB, with the flexibility to add more detection options in the future. The compact PAL spectrometer includes two fast scintillation detectors read by a fast digitizer (DRS4), with a sampling rate of 5.12 GS/s. A dedicated software package was developed to emulate analogue data acquisition. Lifetime measurements were performed using a ∼25 μCi 22Na source. The time resolution was defined using a 60Co source, to be 180-200ps. First positron lifetime validation measurements of Ti resulted in positrons lifetime of 157 ± 4 ps, consistent with previously published values.
|Original language||American English|
|Title of host publication||18th International Conference on Positron Annihilation, ICPA 2018|
|Subtitle of host publication||Positron Annihilation Spectroscopy-Fundamentals, Techniques ad Applications|
|Publisher||American Institute of Physics Inc.|
|State||Published - 27 Dec 2019|
|Event||18th International Conference on Positron Annihilation: Positron Annihilation Spectroscopy-Fundamentals, Techniques ad Applications, ICPA 2018 - Orlando, United States|
Duration: 19 Aug 2018 → 24 Aug 2018
|Name||AIP Conference Proceedings|
|Conference||18th International Conference on Positron Annihilation: Positron Annihilation Spectroscopy-Fundamentals, Techniques ad Applications, ICPA 2018|
|Period||19/08/18 → 24/08/18|
Bibliographical noteFunding Information:
This project is supported by the Ministry of Economy under the KAMIN program and by the Pazy grant of the IAEC. We wish to thank the SPONSOR group at HZDR, Germany, for sharing their knowledge and for guiding and supporting us in all aspects of the source and beam design. Special thanks to Wolfgang Anwand from HZDR, who was always available and willingly devoted his time to teach and help us.
© 2019 Author(s).