guest ::
| Home > Publications database > High-Statistics CDBS Measurements and Ab-Initio Calculations |
| Home > Publications database > High-Statistics CDBS Measurements and Ab-Initio Calculations |
| Journal Article | IMPULSE-2026-00024 |
;
2025
IOP Publ.
Bristol
Please use a persistent id in citations: doi:10.1088/1742-6596/3149/1/012006
Abstract: Coincidence Doppler Broadening Spectroscopy (CDBS) is a positron annihilation technique that allows the measurement of electron momenta within a sample. In CDBS both of the electron-positron annihilation gamma quanta are measured in coincidence. As a result, the Doppler broadened 511 keV photo peak can be measured with much lower background contribution as compared to conventional DBS. Compared to DBS, CDBS not only allows the analysis of open volume defects, but also the chemical surroundings of the positron annihilation site. Recent upgrades of the CDB Spectrometer at the NEutron induced POsitron source MUniCh (NEPOMUC) allow high-statistics bulk measurements in between reactor cycles, using a 22Na positron source. Accurate projections of the material specific electron momentum distribution can be obtained in this way. Using un-moderated positrons from a 22Na source, the implantation depth of the positrons is high enough for bulk measurements. Several reference samples, including metals and semiconductors like Al, Cu, Si and more, as well as, AlCu alloys in various states were measured with high statistics, i.e. at least 107 counts in the coincidence spectrum. The data is analyzed using in house developed software [1] to project the momentum distribution without distorting the data. The projections are subsequently compared to ab-initio calculations using ratio-curves.
Keyword(s): Instrument and Method Development (1st) ; Instrument and Method Development (2nd)
; Nationallizenz
; SCOPUS
|
The record appears in these collections: |
PDF
PDF (PDFA)