Journal article
Improved Slow-Positron Yield using a Single Crystal Tungsten Moderator
Nano-Microstructures in Materials, Materials Research Division, Risø National Laboratory for Sustainable Energy, Technical University of Denmark1
Materials Research Division, Risø National Laboratory for Sustainable Energy, Technical University of Denmark2
Risø National Laboratory for Sustainable Energy, Technical University of Denmark3
A well-annealed W(110) single crystal was used as a fast-to-slow positron moderator. The measured moderator efficiency at room temperature using a58Co positron source in the backscattering geometry isɛ =(3.2±0.4)×10−3, roughly a factor of three better thanɛ for the best previously reported Cu(111)+S moderator.
We find a stable positron moderation efficiency over a period of several weeks when maintained at pressures around 10−9 Torr and an energy spreadΔE = 0.7 eV of the emitted slow positrons. An initial attempt was made to fabricate a hybrid Cu on W(110) moderator, which yieldedɛ of about 1.2×10−3 after annealing.
Language: | English |
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Publisher: | Springer-Verlag |
Year: | 1983 |
Pages: | 163-167 |
Journal subtitle: | Materials Science and Processing |
ISSN: | 14320630 , 09478396 and 07217250 |
Types: | Journal article |
DOI: | 10.1007/BF00616613 |
ORCIDs: | Eldrup, Morten Mostgaard |