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

**Cs-134**

Reviewed by Shen Qingbiao CIAE, February, 2004

**1. Files**

***ENDF/B-VI***: Evaluation was made in 1974. It was converted to new
ENDF/B-VI in 1998.

***JENDL-3.2***: Evaluation was made for JENDL-3 in 1990. It was
converted to JENDL-3.2 in 1994.

***JEF-2.2***: ENDF/B-V was adopted in 1982. The charged particle
production cross sections were added from REAC-ECN-4 library in 1989.
The data were compiled in 1992.

***CENDL-3***: Evaluation was performed in 1999. It was compiled in
2001.

Figs: <http://www.nndc.bnl.gov/sg21/fp21/index.html>

**2. Thermal and resonance region**

\(1\) Resolved resonance parameters

***ENDF/B-VI*** (1.0e-5 eV -- 0.18 keV)

The resolved MLBW resonance parameters were taken from Mughabghab S.
F.\[Mu81\]

***JENDL-3.2*** (1.0e-5 eV --0.179 keV)

The resolved MLBW resonance parameters were taken based on Mughabghab S.
F.\[Mu81\]

***JEF-2.2*** (1.0e-5 eV -- 0.187 keV)

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

***CENDL-3*** (1.0e-5 eV -- 0.179 keV)

JENDL-3.2 was adopted.

\(2\) Unresolved resonance parameters

***ENDF/B-VI*** (0.18 - 100 keV)

The unresolved resonance parameters were revised in 1998.

***JENDL-3.2*** (0.179 - 100 keV)

The neutron strength function S0, S1, and S2 were calculated with
optical model code CASTHY \[Ig75\],

***JEF-2.2***

No unresolved resonance parameters are given.

***CENDL-3*** (0.179 -- 100 keV)

JENDL-3.2 was adopted.

\(3\) Recommendation/conclusion for resonance region

***JENDL-3.2*** (***CENDL-3***) is recommended.

**3. Fast neutron region**

\(1\) Methodology

***ENDF/B-VI***

Theoretical calculation was widely used.

The isotropic distributions were given.

The evaporation energy spectra were given

***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. 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. The charged particle production cross
sections were added from REAC-ECN-4 library.

***CENDL-3***

Calculated with SUNF code. The optical model parameters were determined
with APOM code. The direct inelastic scattering data were calculated by
DWUCK4 code.

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

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

The value and shape of curve of cross sections are reasonable and
acceptable for ***CENDL-3*** and ***JENDL-3.2***. And they are better
than ***ENDF/B-VI*** and ***JEF-2.2.***

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

The value and shape of curve of cross sections are reasonable and
acceptable and closed each other for ***CENDL-3***, ***JENDL-3.2,*** and
***ENDF/B-VI*** . They are better than ***JEF-2.2.***

\(4\) 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 5 levels up to 0.193 MeV
>
> JENDL-3.2 29 levels up to 0.6345 MeV
>
> JEF-2.2 5 levels up to 0.193 MeV
>
> CENDL-3 15 levels up to 0.291 MeV

The shape and value of curve of total inelastic scattering cross
sections of ***CENDL-3*** and ***JENDL-3.2*** are reasonable and
acceptable. And the direct inelastic scattering contribution is
considered for ***CENDL-3***. The shape of curve of total inelastic
scattering cross sections of ***ENDF/B-VI*** and ***JEF-2.2*** is wrong
since no (n,2n) cross sections are given.

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

The shape and value of (n,2n) cross sections of ***CENDL-3*** and
***JENDL-3.2*** are closed each other. Considered the experimental data
of (n,2n) cross sections of Cs-133, they are acceptable. No this file
for ***ENDF/B-VI*** and ***JEF-2.2***.

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

The value of (n,p) cross sections of Cs-134 should be lower than that of
Cs-133. The next Figure shows that the values of ***JENDL-3.2*** and
***JEF-2.2*** are reasonable and the value of ***CENDL-3*** is too
large. The shape of (n,p) cross sections of ***JENDL-3.2*** is better
than ***JEF-2.2***.

![](media/image1.png){width="6.490277777777778in"
height="4.465277777777778in"}

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

The value of (n,) cross sections of Cs-134 should be lower than that of
Cs-133. The next Figure shows that the values of ***JENDL-3.2*** and
***JEF-2.2*** are reasonable and the value of ***CENDL-3*** is too
large. The shape of (n,) cross sections of ***JENDL-3.2*** is better
than ***JEF-2.2***.

![](media/image2.png){width="6.490277777777778in"
height="4.636805555555555in"}

\(9\) Other reactions

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

> JENDL-3.2 (n,3n), (n,n), (n,np), (n,nd), (n,nt), (n,d), (n,t),
> (n,He-3)
>
> CENDL-3 (n,3n), (n,n), (n,np), (n,d), (n,t), (n,He-3)
>
> JEF-2.2 (n,d), (n,t), (n,He-3),(n,2p)
>
> ENDF/B-VI No

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

***JENDL-3.2*** is recommended.

**References**

\[Ba58\] Bayly J. et al., J, JIN, 5, 259, 1958.

\[Ig75\] IGARASI, S.: J. NUCL. SCI. TECHNOL., 12, 67, 1975.

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

Table 1. Summary for Resolved and Unresolved Resonance Region: Cs-134

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

Library RRP URP Remarks

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

ENDF/B-VI 0.18 keV MLBW 10 keV

JENDL-3.2 0.179 keV MLBW 100 keV

JEF-2.2 0.187 keV MLBW No URP

CENDL-3 0.179 keV MLBW 100 keV taken from JENDL-3.2

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

Table 2. Thermal Cross Sections and Resonance Integral: Cs-134

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

Library/Experiment Total Elastic Capture Res.Integ.

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

ENDF/B-VI 162.3 22.7 139.6 102

JENDL-3.2 162.3 22.64 139.7 106

JEF-2.2 162.013 22.3446 139.668 78.8103

CENDL-3 162.314 22.6428 139.671 105.167

Mughabghab et al. \[Mu81\] 14012 54.2

Bayly et al. \[Ba58\] 13412

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