Published May 1976 | Version v1
Journal article Metadata-only

Positron annihilation study of voids in a neutron irradiated aluminium single crystal

Creators

  • 1. Danmarks Tekniske Hoejskole, Lyngby. Applied Physics Lab. 2
  • 2. Oak Ridge National Lab., Tenn. (USA). Metals and Ceramics Div.

Description

We have measured the lifetimes of positrons in an aluminum single crystal which was irradiated to afast neutron fluence of 1.5 x 1021 n/cm2 (> 0.18 MeV) at 500C. These irradiation conditions produced 4.2 x 1014 voids/cm3 with a mean diameter of 330A, as determined by both small-angle X-ray scattering and transmission electron microscopy. The positron lifetime spectra were resolved into three lifetime components of 100, 300, and 500 ps. The short lifetime component is a result of fast trapping of positrons by the voids; the long lifetime components result from annihilations within the voids. The positron diffusion coefficient appears to have a Tsup(1/2)-dependence. (orig.)

Abstract (German)

Wir haben die Lebensdauer von Positronen in einem Aluminium Einkristall gemessen, der vorher bei 500C mit einem Fluss von 1.5 x 1021 n/cm2 schneller Neutronen (> 0.18 MeV) bestrahlt wurde. Diese Bestrahlung erzeugte 4.2 x 1014 Leerstellen/cm3 mit einem mittleren Durchmesser von 330A, was durch Roentgenbeugung bei kleinen Winkeln und durch Elektronenmikroskopie in Durchstrahlung bestimmt wurde. Die Positronen Lebensdauerspektren wurden in drei Lebensdauerkomponenten aufgeloest: 100, 300 und 500 ps. Die kurze Lebensdauerkomponente resultiert aus dem Positroneneinfang durch die Leerstellen; die langen Lebensdauerkomponenten entstehen durch Vernichtung in den Leerstellen. Der Positronen Diffusionskoeffizient hat eine Tsup(1/2)-Abhaengigkeit. (orig./WBU)

Additional details

Identifiers

DOI
10.1007/bf00929532;

Publishing Information

Journal Title
Applied Physics
Journal Volume
10
Journal Issue
1
Series
Appl. Phys.
Journal Page Range
85-90
ISSN
0340-3793

INIS

Country of Publication
Germany
Country of Input or Organization
Germany
INIS RN
7258418
Subject category
S75: CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY;
Descriptors DEI
ALUMINIUM; ANNEALING; ANNIHILATION; DIFFUSION; IRRADIATION; LIFETIME; MONOCRYSTALS; NEUTRON BEAMS; PHYSICAL RADIATION EFFECTS; POSITRONS; SPATIAL DISTRIBUTION; TEMPERATURE DEPENDENCE; VOIDS
Descriptors DEC
ANTILEPTONS; ANTIMATTER; ANTIPARTICLES; BEAMS; CRYSTALS; DISTRIBUTION; ELEMENTARY PARTICLES; ELEMENTS; FERMIONS; HEAT TREATMENTS; INTERACTIONS; LEPTONS; MATTER; METALS; NUCLEON BEAMS; PARTICLE BEAMS; PARTICLE INTERACTIONS; RADIATION EFFECTS

Optional Information

Notes
4 figs.; 17 refs.; Updated automatically by Metadata and Full-Text Enrichment Agent