WPEC SG 21: Assessment of Neutron Cross-Section Evaluations for the Bulk
of Fission Products

**Y-89**

Reviewed by Shen Qingbiao CIAE, February, 2003

**1. Files**

***ENDF/B-VI***: Evaluation was made in 1986 for ENDF/B-V. The thermal
values were added in 1996 for ENDF/B-VI.

***JENDL-3.2***: In 1984, the evaluation was made for JENDL-2. JENDL-2
data were revised in 1990 for JENDL-3.1. The resolved resonance
parameters were modified in 1993 for JENDL-3.2 .

***JEF-2.2***: ENDF/B-V was adopted. In 1990, the resonance parameters
were added from Mughabghab S. F.\[Mu81\].

***CENDL-3***: Evaluation was performed in 1999. The data were compiled
in 2001.

Figs: <http://www.nndc.bnl.gov/~sirakov/fp/fp21/htm/Y89.htm#mt1>

**2. Thermal and resonance region**

\(1\) Resolved resonance parameters

***ENDF/B-VI*** (1.0e-5 eV -- 150 keV)

The resolved resonance region is up to 150 keV. The background cross
sections in resonance region were given.

***JENDL-3.2*** (1.0e-5 eV -- 48 keV)

The evaluation for JENDL-2 was based on the data of Boldeman \[Bo77\]
and Camarda\[Ca77\]. A negative resonance at --251 eV was added for
JENDL-3.

***JEF-2.2*** (1.0e-5 eV -- 150 keV)

Taken from ENDF/B-V. Some resonance parameters were added from
Mughabghab S. F.\[Mu81\].

***CENDL-3*** (1.0e-5 eV -- 150 keV)

ENDF/B-VI was adopted.

\(2\) Unresolved resonance parameters

***ENDF/B-VI***

No unresolved resonance parameters are given.

***JENDL-3.2*** (48 - 100 keV)

The neutron strength function S0 and S1 were adopted from Mughabghab
S.F.\[Mu73\] and were calculated with CASTHY code \[Ig91\].

***JEF-2.2***

No unresolved resonance parameters are given.

***CENDL-3***

No unresolved resonance parameters are given.

\(3\) Recommendation/conclusion for resonance region

***JENDL-3.2*** and ***ENDF/B-VI*** (***CENDL-3, JEF-2***) as well as
its background cross sections are in the same quality.

**3. Fast neutron region**

\(1\) Methodology

***ENDF/B-VI***

Theoretical calculation was widely used.

Legendre coefficients of elastically scattered neutrons were given and
the isotropic distributions were given to the inelastic scattering.

The energy distributions were given

The covariance files (MF=33) were given too.

***JENDL-3.2***

The total, elastic and inelastic scattering, and capture cross sections
were calculated with the

spherical optical model and statistical model code CASTHY. The 12 levels
up to 3.1380 MeV were considered for the inelastic scattering. No direct
inelastic was considered. Other reaction cross sections were calculated
with a preequilibrium and multi-step evaporation code PEGASUS. Sum of
the threshold reaction cross sections were considered as a competing
reaction cross sections in the CASTHY calculation.

Angular distributions of elastic and inelastic scattering were
calculated with CASTHY code. Isotropic distributions were assumed to the
other reactions.

The energy distributions were calculated with PEGUSUS code.

***JEF-2.2***

ENDF/B-V data were adopted.

***CENDL-3***

Calculated with SUNF code and DWUCK4 code \[Ku94\]. The optical model
parameters were determined with APOM code. The 13 levels up to 3.1389
MeV were considered for the inelastic scattering. The direct inelastic
scatterings of 6 levels were calculated by DWUCK4 code.

Angular and energy distributions of neutrons were also calculated with
SUNF code.

\(2\) Total cross section (MT=1)

The total cross sections in 0.15-0.6 MeV region of ***JENDL-3.2*** is
larger than the experimental data and can not reproduce the resonance
structure and its values in 8-20 MeV region are also larger evidently.
The values of ***CENDL-3, ENDF/B-VI,*** ***JEF-2.2*** reproduce well the
experimental data..

\(3\) Capture cross section (MT=102)

***BROND-2*** is less and ***ENDF/B-VI*** is larger than the
experimental data in 0.15-0.6 MeV region and they are larger around 8
MeV and too little above 14 MeV. ***JENDL-3.2*** is better except larger
around 8 MeV. ***CENDL-3*** is better than others compared with the
experimental data..

\(4\) Elastic scattering cross section (MT=2)

This cross section was obtained as (total cross section) -- (sum of
partial cross sections) in the all

libraries.

\(5\) Inelastic scattering cross section (MT=4, 51 -- 91)

Excited levels considered in the files.

> ENDF/B-VI 12 levels up to 3.1350 MeV
>
> JENDL-3.2 12 levels up to 3.1380 MeV
>
> JEF-2.2 12 levels up to 3.1350 MeV
>
> CENDL-3 13 levels up to 3.1389 MeV

The shapes and values of total inelastic scattering cross section of
***CENDL-3*** and ***ENDF/B-VI*** (***JEF-2.2***) are reasonable and
acceptable compared with the experimental data. The value of total
inelastic scattering cross section of ***JENDL-3.2*** is too little
compared with the experimental data.

\(6\) (n,2n) reaction cross section (MT=16)

The shapes and values of (n,2n) cross sections of ***CENDL-3***,
***JENDL-3.2,*** and ***ENDF/B-VI*** (***JEF-2.2***) are all reasonable
and acceptable compared with the experimental data.

\(7\) (n,p) reaction cross section (MT=103)

The shapes and values of (n,p) cross section of ***CENDL-3*** and
***ENDF/B-VI*** (***JEF-2.2***) are reasonable and acceptable compared
with the experimental data. The value of (n,p) cross section of
***JENDL-3.2*** is too larger in 10-14 MeV region compared with the
experimental data.

\(8\) (n,) reaction cross section (MT=107)

The shapes and values of (n,) cross sections of ***CENDL-3***,
***JENDL-3.2,*** and ***ENDF/B-VI*** (***JEF-2.2***) are all reasonable
and acceptable compared with the experimental data.

\(9\) Other reactions

The following other reaction cross sections are given in the files.

> JENDL-3.2 (n,n), (n,np), (n,nd),(n,d), (n,t), (n,He-3)
>
> CENDL-3 (n,n), (n,np), (n,d), (n,t), (n,He-3)
>
> JEF-2.2 (n,n), (n,np), (n,d), (n,t), (n,He-3)
>
> ENDF/B-VI (n,n), (n,np), (n,d), (n,t), (n,He-3)

\(10\) Recommendation/conclusions for fast neutron region

***CENDL-3*** is recommended. The capture cross section of ***CENDL-3***
is better than ***ENDF/B-VI*** and ***JEF-2.2***.The total, total
inelastic, (n,p) cross sections of ***JENDL-3.2*** are not good.

**References**

\[Be51\] Benoist et al. J.,JPR, 12, 584 (1951)

\[Bo77\] Boldeman J.W. et al., Nucl. Sci. Eng., 64, 744 (1977).

\[Ca77\] Camarda H. S., Phys. Rev., C16, 1803 (1977).

\[Ig91\] Igarasi S. and Fukahori, T., JAERI 1321 (1991).

\[Ku94\] Kunz, P. D., 'Distorted Wave Code DWUCK4', University of
Colorado, 1994.

\[Ly56\] Lyon W. S. et al., W., LYON, 1956, USAORL

\[Mu73\] Mughabghab S.F. et al.: "Neutron Cross Sections, Vol.1,
BNL-325, 3^rd^ ed." (1973).

\[Mu81\] Mughabghab S.F. et al.: "Neutron Cross Sections, Vol.1, Part
A," Academic Press (1981).

\[Mu01\] Mughabghab S.F.: *INDC(NDS)*-424, p.69 (2001)

\[Po51\] Pomerance H., J. Phys. Rev., 83, 641 (1951).

\[Ru66\] Rustad B. M. et al., P., NYO-72-28, 92 (1966)

\[Ry71\] Ryves T. B. et al., J. JNE, 25, 129 (1971)

\[Sc60\] Schmunk et al., J, NSE, 7, 193 (1960)

\[Se47\] Seren L. et al., J. Phys. Rev., 72, 888 (1947).

\[Ta78\] Takiue M. J. NIM, 148 (1), 157 (1978)

Table 1. Summary for Resolved and Unresolved Resonance Region: Y-89

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Library RRP URP Remarks

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

ENDF/B-VI 150 keV MLBW No URP

JENDL-3.2 48 keV MLBW 100 keV

JEF-2.2 150 keV MLBW No URP taken from ENDF/B-V

CENDL-3 150 keV MLBW No URP taken from ENDF/B-VI

based on the recommendation of

> Mughabghab et al. \[Mu81\]

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Table 2. Thermal Cross Sections and Resonance Integral: Y-89

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Library/Experiment Total Elastic Capture Res.Integ.

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

ENDF/B-VI 8.992 7.707 1.285 0.917

JENDL-3.2 8.9900 7.7127 1.2773 0.870

JEF-2.2 8.99177 7.70677 1.28500 0.91933

CENDL-3 9.00389 7.72271 1.28118 0.747621

Mughabghab et al. \[Mu81\] 7.670.06 1.280.02 1.00.1

Mughabghab \[Mu01\] 1.280.02

Pomerance \[Po51\] 1.3810%\*1

Seren et al \[Se47\] 1.2420%\*2

Lyon et al \[Ly56\] 1.260.08\*2

Ryves et al \[Ry71\] 1.210.05

Takiue et al \[Ta78\] 1.310.04\*1

Benoist et al \[Be51\] 1.250.2

Rustad et al. \[Ru66\] 7.460.02

Schmunk et al. \[Sc60\] 8.526

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

\*1) Maxwellian averaged

\*2) Spectrum averaged

**[Attachment 2]{.underline}**

Figs: <http://www.nndc.bnl.gov/~sirakov/fp/fp21/htm/Y89.htm#mt1>