Linked Life Data

19113822

Source:http://linkedlifedata.com/resource/pubmed/id/19113822

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2009-2-5
pubmed:abstractText
We study by optical absorption measurements the stability of E'(gamma) centers induced in amorphous silica at room temperature by gamma irradiation up to 79 kGy. A significant portion of the defects spontaneously decay after the end of irradiation, thus allowing the partial recovery of the transparency loss initially induced by irradiation. The decay kinetics observed after gamma irradiation with a 0.6 kGy dose closely resembles that measured after exposure to 2000 pulses of pulsed ultraviolet (4.7 eV) laser light of 40 mJ/cm(2) energy density per pulse. In this regime, annealing is ascribed to the reaction of the induced E'(gamma) centers with diffusing H(2) of radiolytic origin. At higher gamma doses, the decay kinetics becomes unexpectedly slower notwithstanding the progressive growth of the concentration of induced defects. In particular, the annealing kinetics of E'(gamma) centers after 79 kGy irradiation is inconsistent with the reaction parameters between the defect and H(2). To explain this result, on the basis of the quantitative analysis of the kinetics, we propose water-related species to be responsible for the slow room temperature annealing of E'(gamma) after irradiation with such a dose. This model is qualitatively supported by results obtained by IR absorption measurements, which show an increase of the absorption in the spectral region of Si-OH groups.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Feb
pubmed:issn
1520-5215
pubmed:author
pubmed:issnType
Electronic
pubmed:day
12
pubmed:volume
113
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1026-32
pubmed:year
2009
pubmed:articleTitle
Room temperature instability of E'gamma centers induced by gamma irradiation in amorphous SiO2.
pubmed:affiliation
Dipartimento di Scienze Fisiche ed Astronomiche, Universita di Palermo, Via Archirafi 36, 90128 Palermo, Italy.
pubmed:publicationType
Journal Article