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Absolute activity measurement and gamma-ray emission probability for decay of I-126; Medida absoluta da atividade e determinacao da taxa de emissao gama por decaimento do {sup 126} I

Abstract

The accurate knowledge of the gamma-ray emission probability per decay of radionuclides is important in several applications. In the case of {sup 126} I, its importance lies mainly in fast neutron dosimetry as well as in the production of {sup 125} I where {sup 126} I appears as an impurity. In the present work the gamma-ray emission probabilities per decay for the 388 and 666-KeV transitions of {sup 126} I have been measured. This radionuclide was obtained by means of the {sup 127} I(n, 2n){sup 126} I reaction in a fast neutron flux at the IPEN 2 MW research reactor. The methodology for the primary standardization of {sup 126} I is described. For this purpose, two different coincidence systems were used due to the complex decay scheme of this radionuclide. The {beta}branch measurement was carried out in a 4 {pi}(PC){beta}-{gamma} coincidence system consisting of a proportional counter, coupled to a pair of 3'x3' Na I (Tl) crystal. The electron capture branch was measured in a X-{gamma} coincidence system using two NaI(Tl) crystals. The gamma-ray measurements were performed in a HPGe system, previously calibrated by means of standard sources supplied by the International Atomic Energy Agency. All the uncertainties evolved were  More>>
Publication Date:
Jul 01, 1997
Product Type:
Thesis/Dissertation
Report Number:
INIS-BR-3823
Resource Relation:
Other Information: TH: Dissertacao (M.Sc.); 44 refs., 7 figs., 16 tabs., 2 graphs; PBD: 1997
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; BETA DECAY; COINCIDENCE METHODS; DATA COVARIANCES; FAST NEUTRONS; FOUR-PI COUNTING; GAMMA RADIATION; GAMMA SPECTROMETERS; HIGH-PURITY GE DETECTORS; IEAR-1 REACTOR; IODINE 126; IODINE 127 TARGET; NAI DETECTORS; NEUTRON REACTIONS
OSTI ID:
20370140
Research Organizations:
Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)
Country of Origin:
Brazil
Language:
Portuguese
Other Identifying Numbers:
TRN: BR0342810051922
Availability:
Available from INIS in electronic form
Submitting Site:
BRN
Size:
95 pages
Announcement Date:

Citation Formats

Fonseca, Katia Aparecida. Absolute activity measurement and gamma-ray emission probability for decay of I-126; Medida absoluta da atividade e determinacao da taxa de emissao gama por decaimento do {sup 126} I. Brazil: N. p., 1997. Web.
Fonseca, Katia Aparecida. Absolute activity measurement and gamma-ray emission probability for decay of I-126; Medida absoluta da atividade e determinacao da taxa de emissao gama por decaimento do {sup 126} I. Brazil.
Fonseca, Katia Aparecida. 1997. "Absolute activity measurement and gamma-ray emission probability for decay of I-126; Medida absoluta da atividade e determinacao da taxa de emissao gama por decaimento do {sup 126} I." Brazil.
@misc{etde_20370140,
title = {Absolute activity measurement and gamma-ray emission probability for decay of I-126; Medida absoluta da atividade e determinacao da taxa de emissao gama por decaimento do {sup 126} I}
author = {Fonseca, Katia Aparecida}
abstractNote = {The accurate knowledge of the gamma-ray emission probability per decay of radionuclides is important in several applications. In the case of {sup 126} I, its importance lies mainly in fast neutron dosimetry as well as in the production of {sup 125} I where {sup 126} I appears as an impurity. In the present work the gamma-ray emission probabilities per decay for the 388 and 666-KeV transitions of {sup 126} I have been measured. This radionuclide was obtained by means of the {sup 127} I(n, 2n){sup 126} I reaction in a fast neutron flux at the IPEN 2 MW research reactor. The methodology for the primary standardization of {sup 126} I is described. For this purpose, two different coincidence systems were used due to the complex decay scheme of this radionuclide. The {beta}branch measurement was carried out in a 4 {pi}(PC){beta}-{gamma} coincidence system consisting of a proportional counter, coupled to a pair of 3'x3' Na I (Tl) crystal. The electron capture branch was measured in a X-{gamma} coincidence system using two NaI(Tl) crystals. The gamma-ray measurements were performed in a HPGe system, previously calibrated by means of standard sources supplied by the International Atomic Energy Agency. All the uncertainties evolved were treated rigorously, by means of covariance analysis. (author)}
place = {Brazil}
year = {1997}
month = {Jul}
}