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

**Dy-160**

Reviewed by Shen Qingbiao CIAE, February, 2003

**1. Files**

***ENDF/B-VI***: Evaluation was made in 1974 for ENDF/B-V. It was
converted to ENDF/B-VI in 1990. The new/modified ENDF/B-VI evaluation
was made in 1998 in which the resonance parameters and the smooth cross
sections for MF=3, MT=1,2,102 were modified.

***JEF-2.2***: ENDF/B-V was adopted. The resonance parameters were
changed from SLBW to MLBW in 1988.. The data were compiled in 1992.

Figs: <http://www.nndc.bnl.gov/~sirakov/fp/fp21/htm/Dy160.htm#mt1>

**2. Thermal and resonance region**

\(1\) Resolved resonance parameters

***ENDF/B-VI*** (1.0e-5 eV -- 1.69 keV)

The number of resolved resonances is 66. The resonance parameters are
taken from Mughabghab \[Mu84\].

***JEF-2.2*** (1.0e-5 eV -- 0.024441 keV)

The multi level Breit-Wigner resonance parameters were used.

\(2\) Unresolved resonance parameters

***ENDF/B-VI*** (1.69 -- 20 keV)

The unresolved resonance parameters are based on Mughabghab \[Mu84\] and
\[RIPL98\].

***JEF-2.2***

No unresolved resonance parameters are given.

\(3\) Recommendation/conclusion for resonance region

***ENDF/B-VI*** is recommended.

**3. Fast neutron region**

\(1\) Methodology

***ENDF/B-VI***

Theoretical calculation was widely used. The optical potential of
Moldauer was adopted.

Inelastic scattering was calculated with COMNUC-3 code, and the capture
cross section with

NCAP code. No direct inelastic was considered. No threshold reaction
cross sections are given.

Isotropic distributions were given to the elastic and inelastic
scattering.

Evaporation spectra were given to the continuum inelastic scattering.

***JEF-2.2***

ENDF/B-V data were adopted.

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

The total cross sections of ENDF/B-VI pass through the only experimental
data at around 14 MeV. The shape of the total CS of JEF2.2 is not good
compared with the experimental data of natural element (see 66-Dy 164
review).

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

The values of ENDF/B-VI are basically agreement with the experimental
data. The values of JEF2.2 are too high.

\(4\) 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 13 levels up to 1.59 MeV
>
> JEF-2.2 13 levels up to 1.59 MeV

No experimental data of total inelastic scattering cross section are
available. Only ENDF/B-VI (JEF2.2) can be chosen. Its shape in low
energy region is not smooth and the shape in high energy region is wrong
since no (n,2n) cross sections are given..

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

No (n,2n) cross sections are given for ENDF/B-VI (JEF2.2).

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

No (n,p) cross sections are given for ENDF/B-VI (JEF2.2).

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

No (n, ) cross sections are given for ENDF/B-VI (JEF2.2).

\(9\) Other reactions

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

> JEF-2.2 no
>
> ENDF/B-VI no

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

***ENDF/B-VI*** is recommended. But it has no threshold reaction cross
sections and some reaction cross sections are not good. It needs to be
improved evidently.

**References**

\[Lu77\] Lucas M. et al., C, 77Paris, 1, 431 (1977), IAEA-Publ., 475

\[Mu84\] Mughabghab S.F. et al.: "Neutron Cross Sections, Vol.1, Part
B," Academic Press (1984)

\[RIPL98\]. 'Reference Input Parameter Library', IAEA-TECDOC-1034, 1998.

\[Sc66\] Scoville J. J., J, NSE, 25, 12 (1966).

Table 1. Summary for Resolved and Unresolved Resonance Region: Dy-160

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

Library RRP URP Remarks

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

ENDF/B-VI 1.69 keV 20 keV

JEF-2.2 0.024441 keV No URP

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

Table 2. Thermal Cross Sections and Resonance Integral: Dy-160

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

Library/Experiment Total Elastic Capture Res.Integ.

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

ENDF/B-VI 63.3217 2.30867 61.0130 1674.4

JEF-2.2 63.3217 2.30867 61.0130 1674.4

Mughabghab et al. \[Mu84\] 5.60.7 565 1160130

Scoville et al. \[Sc66\] 559\*1 1160130

Lucas et al. \[Lu77\] 95 1350

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

\*1) Maxwellian averaged

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

Figs: <http://www.nndc.bnl.gov/~sirakov/fp/fp21/htm/Dy160.htm#mt1>