Accuracy of the activation energy calculated from a thermoluminescence glow‐peak using a method that uses three points on the peak
- Ogundare, F O, Chithambo, Makaiko L
- Authors: Ogundare, F O , Chithambo, Makaiko L
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123016 , vital:35397 , https://doi:10.1002/pssc.200521077
- Description: The utility of thermoluminescence (TL) in detecting changes in defect concentration in insulators is well established [1–3]. The underlying premise leading to the emission of TL is that exposure of a material to ionizing radiation causes a redistribution of charge in defect centres within the material. When the material is heated at a controlled linear rate, the thermoluminescence is emitted as a temperature-dependent set of peaks collectively known as a glow-curve. The shape and intensity of each of the glow-peaks may be characterized by a set of parameters consisting of the activation energy E, the frequency factors, the number of electrons n0 trapped in defect centres at the start of the heating, and the order of kinetics b. The order of kinetics b is an indication of the retrapping probability i.e. the probability that a free electron from the conduction band will be retrapped rather than recombine with a hole at a recombination centre to produce thermoluminescence. Retrapping of electrons reduces the TL intensity at any particular temperature during the heating process. The physical mechanisms of TL associated with a given glow curve are unique and may be characterized by analysis of the glow-curve for the said kinetic parameters.
- Full Text:
- Date Issued: 2006
- Authors: Ogundare, F O , Chithambo, Makaiko L
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123016 , vital:35397 , https://doi:10.1002/pssc.200521077
- Description: The utility of thermoluminescence (TL) in detecting changes in defect concentration in insulators is well established [1–3]. The underlying premise leading to the emission of TL is that exposure of a material to ionizing radiation causes a redistribution of charge in defect centres within the material. When the material is heated at a controlled linear rate, the thermoluminescence is emitted as a temperature-dependent set of peaks collectively known as a glow-curve. The shape and intensity of each of the glow-peaks may be characterized by a set of parameters consisting of the activation energy E, the frequency factors, the number of electrons n0 trapped in defect centres at the start of the heating, and the order of kinetics b. The order of kinetics b is an indication of the retrapping probability i.e. the probability that a free electron from the conduction band will be retrapped rather than recombine with a hole at a recombination centre to produce thermoluminescence. Retrapping of electrons reduces the TL intensity at any particular temperature during the heating process. The physical mechanisms of TL associated with a given glow curve are unique and may be characterized by analysis of the glow-curve for the said kinetic parameters.
- Full Text:
- Date Issued: 2006
Anomalous behaviour of thermoluminescence from quartz: a case of glow peaks from a Nigerian quartz
- Ogundare, F O, Chithambo, Makaiko L, Oniya, E O
- Authors: Ogundare, F O , Chithambo, Makaiko L , Oniya, E O
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6796 , http://hdl.handle.net/10962/d1003922
- Description: Anomalous behaviour displayed by a thermoluminescence (TL) glow peak as radiation dose increases in a Nigerian quartz is presented. The glow curves of the phosphor have four clear glow peaks. The peak temperatures of the first three glow peaks were found to be constant with change in radiation dose at 82, 148 and 200ºC for the sample readout at a heating rate of 1ºCs[superscript (-1)]. The peak temperature of the fourth peak, which is at around 320ºC for a sample irradiated to a dose of 63 Gy and heated at 1ºCs[superscript (-1)], displays anomalous behaviour with increase in dose relative to the first three peaks. The temperature at which this peak occurs increases with dose to about 335ºC for 177 Gy and then decreases thereafter as dose is further increased. The change is explained on the assumption that the peak may be complex consisting of several overlapping first-order glow peaks each with different TL behaviour.
- Full Text:
- Date Issued: 2006
- Authors: Ogundare, F O , Chithambo, Makaiko L , Oniya, E O
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6796 , http://hdl.handle.net/10962/d1003922
- Description: Anomalous behaviour displayed by a thermoluminescence (TL) glow peak as radiation dose increases in a Nigerian quartz is presented. The glow curves of the phosphor have four clear glow peaks. The peak temperatures of the first three glow peaks were found to be constant with change in radiation dose at 82, 148 and 200ºC for the sample readout at a heating rate of 1ºCs[superscript (-1)]. The peak temperature of the fourth peak, which is at around 320ºC for a sample irradiated to a dose of 63 Gy and heated at 1ºCs[superscript (-1)], displays anomalous behaviour with increase in dose relative to the first three peaks. The temperature at which this peak occurs increases with dose to about 335ºC for 177 Gy and then decreases thereafter as dose is further increased. The change is explained on the assumption that the peak may be complex consisting of several overlapping first-order glow peaks each with different TL behaviour.
- Full Text:
- Date Issued: 2006
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