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Characterization of the 4oxo2,2,6,6tetramethylpiperidinooxy dosimeter for
in situ radiolysis electron spin resonance studies.
Keith P. Madden
Radiat. Res. 147, 335341 (1997)
NDRL 3935
The stable free radical 4oxo2,2,6,6tetramethylpiperidinooxy (2,2,6,6tetram
ethylpiperidoneNoxyl, TEMPONE) in nitrous oxidesaturated aqueous formate
solution has been shown to be a quantitative dosimeter for in situ radiolysis
electron spin resonance (ESR) studies. The bleach of the TEMPONE ESR signal
is proportional to the absorbed dose in steadystate
radiolysis/field-modulation and in pulse radiolysis/timeresolved studies.
The G value for consumption of TEMPONE in nitrogendeoxygenated solution is
5.3 (molecules per 100 eV), while the value in nitrous oxidesaturated
solution is 6.0. Measurement of the radiolytically produced yield of carbon
dioxide shows that the product of reaction of carbon dioxide radical anion
with TEMPONE gives the corresponding hydroxylamine. The stability of the
integrated intensity of the TEMPONE ESR bleach has been evaluated in the
presence and absence of oxygen and found to be stable for hours. The ESR
linewidth of TEMPONE solutions irradiated under anoxic conditions was
constant in the postirradiation period. However, when oxygen was added
postirradiation, the oxygenbroadened ESR linewidth decreased slowly toward
the width observed in anoxic media, indicating consumption of dioxygen by,
with concomitant production of, diamagnetic species in solution.
Characterization of the 4oxo2,2,6,6tetramethylpiperidinooxy dosimeter for
in situ radiolysis electron spin resonance studies.
Keith P. Madden
Radiat. Res. 147, 335341 (1997)
NDRL 3935
The stable free radical 4oxo2,2,6,6tetramethylpiperidinooxy
(2,2,6,6tetramethylpiperidoneNoxyl, TEMPONE) in nitrous oxidesaturated
aqueous formate solution has been shown to be a quantitative dosimeter for in
situ radiolysis electron spin resonance (ESR) studies. The bleach of the
TEMPONE ESR signal is proportional to the absorbed dose in steadystate
radiolysis/field-modulation and in pulse radiolysis/timeresolved studies.
The G value for consumption of TEMPONE in nitrogendeoxygenated solution is
5.3 (molecules per 100 eV), while the value in nitrous oxidesaturated
solution is 6.0. Measurement of the radiolytically produced yield of carbon
dioxide shows that the product of reaction of carbon dioxide radical anion
with TEMPONE gives the corresponding hydroxylamine. The stability of the
integrated intensity of the TEMPONE ESR bleach has been evaluated in the
presence and absence of oxygen and found to be stable for hours. The ESR
linewidth of TEMPONE solutions irradiated under anoxic conditions was
constant in the postirradiation period. However, when oxygen was added
postirradiation, the oxygenbroadened ESR linewidth decreased slowly toward
the width observed in anoxic media, indicating consumption of dioxygen by,
with concomitant production of, diamagnetic species in solution.
in situ radiolysis electron spin resonance studies.
Keith P. Madden
Radiat. Res. 147, 335341 (1997)
NDRL 3935
The stable free radical 4oxo2,2,6,6tetramethylpiperidinooxy (2,2,6,6tetram
ethylpiperidoneNoxyl, TEMPONE) in nitrous oxidesaturated aqueous formate
solution has been shown to be a quantitative dosimeter for in situ radiolysis
electron spin resonance (ESR) studies. The bleach of the TEMPONE ESR signal
is proportional to the absorbed dose in steadystate
radiolysis/field-modulation and in pulse radiolysis/timeresolved studies.
The G value for consumption of TEMPONE in nitrogendeoxygenated solution is
5.3 (molecules per 100 eV), while the value in nitrous oxidesaturated
solution is 6.0. Measurement of the radiolytically produced yield of carbon
dioxide shows that the product of reaction of carbon dioxide radical anion
with TEMPONE gives the corresponding hydroxylamine. The stability of the
integrated intensity of the TEMPONE ESR bleach has been evaluated in the
presence and absence of oxygen and found to be stable for hours. The ESR
linewidth of TEMPONE solutions irradiated under anoxic conditions was
constant in the postirradiation period. However, when oxygen was added
postirradiation, the oxygenbroadened ESR linewidth decreased slowly toward
the width observed in anoxic media, indicating consumption of dioxygen by,
with concomitant production of, diamagnetic species in solution.
Characterization of the 4oxo2,2,6,6tetramethylpiperidinooxy dosimeter for
in situ radiolysis electron spin resonance studies.
Keith P. Madden
Radiat. Res. 147, 335341 (1997)
NDRL 3935
The stable free radical 4oxo2,2,6,6tetramethylpiperidinooxy
(2,2,6,6tetramethylpiperidoneNoxyl, TEMPONE) in nitrous oxidesaturated
aqueous formate solution has been shown to be a quantitative dosimeter for in
situ radiolysis electron spin resonance (ESR) studies. The bleach of the
TEMPONE ESR signal is proportional to the absorbed dose in steadystate
radiolysis/field-modulation and in pulse radiolysis/timeresolved studies.
The G value for consumption of TEMPONE in nitrogendeoxygenated solution is
5.3 (molecules per 100 eV), while the value in nitrous oxidesaturated
solution is 6.0. Measurement of the radiolytically produced yield of carbon
dioxide shows that the product of reaction of carbon dioxide radical anion
with TEMPONE gives the corresponding hydroxylamine. The stability of the
integrated intensity of the TEMPONE ESR bleach has been evaluated in the
presence and absence of oxygen and found to be stable for hours. The ESR
linewidth of TEMPONE solutions irradiated under anoxic conditions was
constant in the postirradiation period. However, when oxygen was added
postirradiation, the oxygenbroadened ESR linewidth decreased slowly toward
the width observed in anoxic media, indicating consumption of dioxygen by,
with concomitant production of, diamagnetic species in solution.