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Determination of the branching ratios of the decay of I-135 and Xe-135m
INORG.
NUCL.
CHEM. LETTERS
DETERMINATION
Vol.
12,
pp.
243-245,
1976.
BRANCHING
OF T ~
Pergamon
RATIOS
Press.
Printed
in
Great
Britain
OF THE DECAY OF
1-135 AND X e - 1 3 5 m H . F e u e r s t e i n and J.Oschinski, Gesellschaft f~r K e r n f o r s c h u n g mbH, 75 K a r l s r u h e , G e r m a n y , W e b e r s t r a B e 5 (Received 1 August 1975; in revised form 15 October 1975)
Experiments
performed with the Fission Product Loop
and 1974 (I)(2) the behavior
showed
some unexpected
of X e - 1 3 5 m
and Xe-135.
at that time on the branching and Xe-135m, Iodine
we determined
was separated
technique sample
about
ratios experimentally.
after irradiation
in the FR2 reactor.
into the aqueous phase
available
of the decay of 1-135
from fission products
Io hours
in 1973
concerning
No data were
ratios
these
results
Afterwards
by an extraction of an uranium
it was reextracted
as I-. Two kinds of experiments
were
performed. To determine xenon
the branching
isotopes
ratio of the decay of 1-135,
just produced were
by an argon stream.
This argon
detector,
attached
analyzer.
The Y-lines
Io seconds,
of the xenon Xe-135m
which
isotopes,
the transport
of the argon
the ratio
the branching
After
charcoal
trap where
5 to Io minutes
stream was less
of the production
rates
of
directly.
ratio
of the X e - 1 3 5 m
was used as the sweep gas, passing cooled
time to and
is short compared with the half lives
and X e - 1 3 5 was measured
To determine
at 527 keV and of Xe-135
Because
the delay time at the detector than
over a Ge(Li)
Data 44oo multichannel
of X e - 1 3 5 m
at 25o keV were measured.
swept out of the solution
stream passed
to a N u c l e a r
the
through
the xenon
collection
decay,
a liquid nitrogen
isotopes were
adsorbed.
time the activities
243
helium
of
244
The Decay of I-135 and Xe-135m
Xe-135m and Xe-135 in the trap were measured.
After the
decay of Xe-135m the activity of Xe-135 was measured again. From the initial values for Xe-155m and Xe-155 and the final value of Xe-135,
the branching ratio of the Xe-135m decay
was calculated. For all calculations Xe-135m
the following decay data were used (3):
: half life 15.6 m, 527 keV T-line with 8o.o % yield,
Xe-135
: half life
9.14h,
25o keV y-line with
92.o % yield.
Results
and Discussion
The decay scheme shows the results of our measurements.
\
o5
84.5± 0.5 %/"/
\
Xe- 135 x ~ ~ Cs- 135
The Decay of 1-135 and Xe-135m
245
Because of the half life relation between Xe-135m and Xe-135 and, hence, the very low increase in the counting rate of Xe-135 due to the decay of Xe-135m, the data of the branching ratio of the Xe-135m decay were scattered over a wide range. From our measurements 65 to 88 % of the Xe-135m decays forming Xe-135, the most probable value is higher than 75 %. The results of the branching ratio of the 1-135 decay are in very good agreement with the data now published. Fukuda and Omori found, that 15.o ~ o.8 % of 1-135 decays forming Xe-135m (4), while Meek and Rider list a value of 14.7 % (5). Our experimental result is 15.5 + o.5 %.
Re ference s
I.
I.FUJII, M.OHNO, K.TA/uq~HARA, H.OKANO, T.MIYAZAWA, T.ISHIZAKA, A.YOKOZAWA, H.KA21AI, N.MITSUTSUKA, M.HADA, T.NAGAMINE, J.of the British Nuclear Energy Society 13 (1974),4o3
2.
Results to be published
3.
G.ERDTMANN and W.SOYKA, J ~ - 1 o o 3 - A C
4.
T.FUKUDA and S.OMORI, J.of the Atomic Energy Society
(1973)
of Japan 17 (1975),177 5.
M.E.MEEK and B.F.RIDER, NEDO-12154 (1974)
NUCL.
CHEM. LETTERS
DETERMINATION
Vol.
12,
pp.
243-245,
1976.
BRANCHING
OF T ~
Pergamon
RATIOS
Press.
Printed
in
Great
Britain
OF THE DECAY OF
1-135 AND X e - 1 3 5 m H . F e u e r s t e i n and J.Oschinski, Gesellschaft f~r K e r n f o r s c h u n g mbH, 75 K a r l s r u h e , G e r m a n y , W e b e r s t r a B e 5 (Received 1 August 1975; in revised form 15 October 1975)
Experiments
performed with the Fission Product Loop
and 1974 (I)(2) the behavior
showed
some unexpected
of X e - 1 3 5 m
and Xe-135.
at that time on the branching and Xe-135m, Iodine
we determined
was separated
technique sample
about
ratios experimentally.
after irradiation
in the FR2 reactor.
into the aqueous phase
available
of the decay of 1-135
from fission products
Io hours
in 1973
concerning
No data were
ratios
these
results
Afterwards
by an extraction of an uranium
it was reextracted
as I-. Two kinds of experiments
were
performed. To determine xenon
the branching
isotopes
ratio of the decay of 1-135,
just produced were
by an argon stream.
This argon
detector,
attached
analyzer.
The Y-lines
Io seconds,
of the xenon Xe-135m
which
isotopes,
the transport
of the argon
the ratio
the branching
After
charcoal
trap where
5 to Io minutes
stream was less
of the production
rates
of
directly.
ratio
of the X e - 1 3 5 m
was used as the sweep gas, passing cooled
time to and
is short compared with the half lives
and X e - 1 3 5 was measured
To determine
at 527 keV and of Xe-135
Because
the delay time at the detector than
over a Ge(Li)
Data 44oo multichannel
of X e - 1 3 5 m
at 25o keV were measured.
swept out of the solution
stream passed
to a N u c l e a r
the
through
the xenon
collection
decay,
a liquid nitrogen
isotopes were
adsorbed.
time the activities
243
helium
of
244
The Decay of I-135 and Xe-135m
Xe-135m and Xe-135 in the trap were measured.
After the
decay of Xe-135m the activity of Xe-135 was measured again. From the initial values for Xe-155m and Xe-155 and the final value of Xe-135,
the branching ratio of the Xe-135m decay
was calculated. For all calculations Xe-135m
the following decay data were used (3):
: half life 15.6 m, 527 keV T-line with 8o.o % yield,
Xe-135
: half life
9.14h,
25o keV y-line with
92.o % yield.
Results
and Discussion
The decay scheme shows the results of our measurements.
\
o5
84.5± 0.5 %/"/
\
Xe- 135 x ~ ~ Cs- 135
The Decay of 1-135 and Xe-135m
245
Because of the half life relation between Xe-135m and Xe-135 and, hence, the very low increase in the counting rate of Xe-135 due to the decay of Xe-135m, the data of the branching ratio of the Xe-135m decay were scattered over a wide range. From our measurements 65 to 88 % of the Xe-135m decays forming Xe-135, the most probable value is higher than 75 %. The results of the branching ratio of the 1-135 decay are in very good agreement with the data now published. Fukuda and Omori found, that 15.o ~ o.8 % of 1-135 decays forming Xe-135m (4), while Meek and Rider list a value of 14.7 % (5). Our experimental result is 15.5 + o.5 %.
Re ference s
I.
I.FUJII, M.OHNO, K.TA/uq~HARA, H.OKANO, T.MIYAZAWA, T.ISHIZAKA, A.YOKOZAWA, H.KA21AI, N.MITSUTSUKA, M.HADA, T.NAGAMINE, J.of the British Nuclear Energy Society 13 (1974),4o3
2.
Results to be published
3.
G.ERDTMANN and W.SOYKA, J ~ - 1 o o 3 - A C
4.
T.FUKUDA and S.OMORI, J.of the Atomic Energy Society
(1973)
of Japan 17 (1975),177 5.
M.E.MEEK and B.F.RIDER, NEDO-12154 (1974)