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LLFP Cross-Section Measurements

2006 Symposium on Nuclear Data

SND2006-V.01-A1

Experimental Conditions
8MW Los Alamos
Omega West Reactor
coreIrrad. Sample
93Zr enriched 114.0-mg
107Pd//
201.4-mg(CH2)n 100.0-mg〜1.5m-rays

Pb shield

Graphitethermal column
Flux 〜6×1011 n/cm2s
Cd(In) ratio 〜 2000
Maxwell distribution

2006 Symposium on Nuclear Data

Ge(Li) detector

NaI(Tl) detector

Anti-Compton mode
Pair-spectrometer mode

SND2006-V.01-A2

Isotopic Compositions of Samples
Zirconium
MassAtom(%)

Palladium
MassAtom(%)

90919293
94
96

2.29 518.61 1018.95 1019.98 1020.50 1019.67 10

104
105
106
107
1081101.61 248.50 522.90 515.54 58.77 22.68 2

2006 Symposium on Nuclear Data

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Prompt -ray Spectrum of Pd sample

2006 Symposium on Nuclear Data

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Counts

Counts

Prompt -ray Spectrum of Zr sample（Anti-Compton mode)

2006 Symposium on Nuclear Data

Channel

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Counts

Counts

Prompt -ray Spectrum of Zr sample（Pair-Spectrometer mode)

2006 Symposium on Nuclear Data

Channel

SND2006-V.01-A6

Emission Intensity:I
Intensity Ig is given by :InH H YxnxYHx

H

wherenH, nx : Ammounts of H and Samples (Zr or Pd): Efficiency for 2.2-MeVγray
H: Efficiencies forγrays from samplesx: Cross-section of 1H 332.6±0.7(mb)H
YH : Yield of 2.2-MeVγray
Yx : Yields of γrays from Samples
2006 Symposium on Nuclear Data

SND2006-V.01-A7

Level Scheme for 94Zr
mainly based on the well-known information

2006 Symposium on Nuclear Data

SND2006-V.01-A8

Level Scheme for 108Pd
mainly based on the well-known information

2006 Symposium on Nuclear Data

SND2006-V.01-A9

Intensities I g.s.for the rays feeding the g.s. of 94Zr

918.8
1671.52846.54225.2

Intensity I g.s.
(mb)
544±1853±227±15±18217.45±1

Observed E(keV)

Ig .s.

2006 Symposium on Nuclear Data

0.63 0.02 (b)(Lower Limit)

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Results
Present results for 91Zr and 93Zr cross sections
together with reported data
0 for91Zr

0 for(b)References93Zr(b)H.Pomerancea)

1952

1.52 ± 0.12

1.3 <Garrison et al.b)1962

1.2 ± 0.3

1.1 ± 0.4Claytonc)

1972

1.579

1.996

Mughabghab et al.

1981

1.24 ± 0.25

1.3 <T.O.I 8ed.

1998

1.24 ± 0.25

2.7 ± 1.4

JENDL-3.3

2002

1.247

2.239

Present Result (lower limit)

1.30 ± 0.04

0.63 ± 0.02

Present Result (estimation)

1.5 ± 0.2

0.76 ± 0.13

0 < 40 < 4a) Measurements with ORNL pile oscillatorb) Statistical Model estimates

Calculation by the resonance parameters from BNL-325c)
2006 Symposium
on Nuclear Data

SND2006-V.01-A11

Intensities I g.s.for the rays feeding the g.s. of 108Pd

434.0
931.1
1053.51441.71540.02097.62477.4

Intensity I g.s.
(mb)
7588±255
606±19488±73
214±8
104±6
83±6
72±7

I

9.16 0.27 (b)Observed E(keV)g .s.
2006 Symposium on Nuclear Data

(Lower Limit)
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Gamma-ray intensity balance for the 434 keV level

INOUTE a)

Intensity I b)

E a)

Intensity I b)

497.2 3

1940 63

1664.4 334 4614.3 32168 81

1784.3 3

117 7618.2 3454 30

1846.9 3133 6880.1 393 41956.3 345 5901.3 3713 23

1969.9 333 41007.2 3399 132044.3 3133 81105.9 3169 92106.5 3103 71189.9 3

39 52285.4 382 81554.9 442 82453.8 627 61612.6 3374 18

434.0 37588 255

I (in) =7.10±0.11 (b)a)

I (out) = 7.59±0.26 (b)In our notation,497.2 3 is 497.2 ± 0.3 keV, etc.
ray cross section in mb. In our notation, 1929 44 is 1929 ± 44, etc.

b) on Nuclear Data
2006 Symposium

SND2006-V.01-A13

Experimental and evaluated datafor 107Pd & 105Pd cross-sections
References for 107Pd0 (b)I0 (b)

Singh et al.

1978

―87

Mughabghab et al.

1981

1.8 ± 0.2

86.6

Macklin1985―

108.1 ± 4.3

T.O.I. 8ed.

1998

1.8 ± 0.2―

JENDL-3.3

2002

2.0071

112.2

9.16 ± 0.27―

Present Result

0 (b)References for 105Pd
T.O.I. 8ed.

1998

20.0 ± 3.0

JENDL-3.3

2002

20.25

Mughabghab

2003

21.0 ± 1.5

Firestone et al.

2005

21.1 ± 1.5 *Present result
2006 Symposium on Nuclear Data

19.1± 0.5 *SND2006-V.01-A14