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

**Pm-147**

Reviewed by Shen Qingbiao CIAE, February, 2003

**1. Files**

***ENDF/B-VI***: Evaluation was made in 1974 for ENDF/B-V. The revised
file for ENDF/B-VI was made by R. Q. Wright in 1989 mainly for resonance
parameters.

***JENDL-3.2***: In 1984, the evaluation was made for JENDL-2. JENDL-2
data were revised in 1990 for JENDL-3.1. JENDL-3.2 is the same as
JENDL-3.1.

***JEF-2.2***: Evaluation was made in 1983. Some revision and
modification were made in 1985 and 1988. In 1989, the charged particle
emission cross sections were adopted from REAC-ECN-4.

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

***BROND-2***: The evaluation was made in1984 and it was converted to
ENDF-6 format.

Figs: <http://www.nndc.bnl.gov/~sirakov/fp/fp21/htm/Pm147.htm#mt1>

**2. Thermal and resonance region**

\(1\) Resolved resonance parameters

***ENDF/B-VI*** (1.0e-5 eV -- 0.3 keV)

The resolved resonance region is up to 0.3 keV. The resolved resonance
parameters were taken from \[Mu84\]. Two bound levels at --22.1 and
--8.88 eV are used in this evaluation.

***JENDL-3.2*** (1.0e-5 eV -- 0.102 keV)

The resolved resonance parameters of MLBW formula were used below 102 eV
and a negative resonance was added so as to reproduce the thermal
capture and elastic scattering cross sections given by Mughabghab
\[Mu84\].

***JEF-2.2*** (1.0e-5 eV -- 0.319 keV)

The resolved resonance parameters of MLBW formula given by Mughabghab
\[Mu84\] were used below 319 eV. L=0 has been assumed for all resonance
states. A negative resonance has been assumed at --1.8 eV to fit the
value of the thermal capture cross section.

***CENDL-3*** (1.0e-5 eV -- 0.102 keV)

JENDL-3.2 was adopted.

***BROND-2*** (1.0e-5 eV -- 0.3 keV)

The resolved resonance parameters of MLBW formula were used below 300
eV. A negative resonance at --1.8 eV was added in order to fit the
experimental data.

\(2\) Unresolved resonance parameters

***ENDF/B-VI*** (0.3 -- 20 keV)

The unresolved resonance parameters are based on D0=3.6 eV and S0=3.1
\[Mu84\].

***JENDL-3.2*** (0.102 -- 100 keV)

The neutron strength function S0 was based on the compilation of
Mughabghab \[Mu84\], S1 and S2 were calculated with optical model code
CASTHY. The observed level spacing was determined to reproduce the
capture cross section calculated with CASTHY.

***JEF-2.2***(0.319 -- 50 keV)

The strength function region is up to 50 keV. Capture cross sections
were calculated with code FISPRO-ECN. Other cross sections were
calculated with code SASSI-ECN.

***CENDL-3*** (0.102 -- 100 keV)

JENDL-3.2 was adopted.

***BROND-2*** (0.3 -- 100 keV)

Energy dependent average resonance widths were taken. These widths were
calculated with EVPAR code.

\(3\) Recommendation/conclusion for resonance region

***JENDL-3.2*** (***CENDL-3***) or ***ENDF/B-VI*** is recommended. The
data of ***JEF-2.2*** and ***BROND-2*** are too old.

No experimental data of thermal elastic scattering cross section are
available. ***JENDL-3.2*** (***CENDL-3***) and ***ENDF/B-VI*** are in
the same quality.

**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 COMNUC-3 and NCAP codes. No
direct inelastic was considered. The threshold reaction cross sections
were calculated with THRESH code \[Pe73\]. .

Legendre coefficients of elastically scattered neutrons were calculated
from Moldauer potential.

Isotropic distributions were given to the inelastic scattering.

The spectra were given to the continuum inelastic scattering and some
threshold reactions. .

***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 gamma-ray strength function was determined from the
systematics. Direct and semi-direct capture cross sections were
estimated. The direct inelastic scattering contribution was not
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***

All cross sections were calculated with code SASSI-ECN. Optical model
calculations were taken from Igarasi et al.

***CENDL-3***

Calculated with SUNF code and DWUCK-4 code. The optical model parameters
were determined with APOM code. The direct inelastic scatterings of some
discrete levels were calculated by DWUCK4 code.

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

***BROND-2***

JENDL-1 was adopted in the energy region above 100 keV except the (n,2n)
and (n,3n) cross sections were taken from ENDF/B-V. Optical and
statistical models were used.

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

All libraries are in better agreement with the experimental data in
2.5-15 MeV region. But ENDF/B-VI seems too high in low energy region
where no experimental data are available.

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

No experimental data are available for Pm147 capture cross section. The
shapes of the capture cross section of ***JENDL-3.2*** and ***CENDL-3***
are better than other libraries in high energy region..

\(4\) 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 0.54625 MeV
>
> JENDL-3.2 6 levels up to 0.6858 MeV
>
> JEF-2.2 11 levels up to 0.6861 MeV
>
> CENDL-3 9 levels up to 0.6672 MeV
>
> BROND-2 6 levels up to 0.6859 MeV

No experimental data are available for Pm147 total inelastic scattering
cross section. The direct inelastic scattering was considered in CENDL-3
library only. The curve shape in high energy region is decided by (n,2n)
cross section.

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

No experimental data are available for Pm147 (n,2n) cross section. The
difference of the shapes of the different libraries is pretty large. The
experience shows that the changing of the (n,2n) cross sections with the
different closed nuclei is not very large. The following figure compares
the evaluated data with the measured (n,2n) cross sections of the closed
nucleus Gd156. Z=61 N=86, and A=161 for Pm147; Z=64, N=92, and A=156 for
Gd156. They have the closed even number neutrons. Their thresholds of
(n,2n) cross section are closed. The experimental data of (n,2n) cross
sections of the closed nucleus Gd156 show that the shape of (n,2n) cross
sections of CENDL-3 is reasonable. The curve shape of JEF-2.2 is not
good.

![](media/image1.png){width="6.490277777777778in"
height="5.5784722222222225in"}

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

No experimental data are available for Pm147 (n,p) cross section. The
difference for different libraries is 2 - 3 times. They are all in the
reasonable range compared with the closed nuclei.

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

No experimental data are available for Pm147 (n,) cross section. The
difference for different libraries is less than 2 times. They are all in
the reasonable range compared with the closed nuclei.

\(9\) 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 (n,3n), (n,n), (n,np), (n,d), (n,t), (n,He-3)
>
> BROND-2 (n,3n)

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

***CENDL-3*** or ***JENDL-3.2*** is recommended. The contribution of the
direct inelastic scattering was considered in ***CENDL-3.***

**References**

\[Bi58\] Bidinosti D. et al., C, 58GENEVA, 15, 459(201) (1958)

\[Ca70\] Cabell M. J., J, JIN, 32, 3433 (1960)

\[Fe67\] Fenner N. C. et al., J, JIN, 29, 2147 (1967)

\[Ki73\] Kirouac G. J. et al., J, NSE, 52, 310 (1973)

\[Mo71\] Mowatt R. S. et al., J, CJP, 49, 108 (1971)

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

\[Pe73\] Pearlstein, Jour. Nucl. Energy 27, 81 (19730.

\[Sc62\] Schuman R. P. et al., J, NSE, 12, 519 (1962)

\[St60\] Stoughton R. W. et al., C, 60VIENNA, 239 (1960)

Table 1. Summary for Resolved and Unresolved Resonance Region: Pm-147

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

Library RRP URP Remarks

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

ENDF/B-VI 0.3 keV MLBW 20 keV

JENDL-3.2 0.102 keV MLBW 100 keV

JEF-2.2 0.319 keV SLBW 50 keV

CENDL-3 0.102 keV MLBW 100 keV taken from JENDL 3.2

BROND-2 0.3 keV MLBW 100 keV

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

Table 2. Thermal Cross Sections and Resonance Integral: Pm-147

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

Library/Experiment Total Elastic Capture Res.Integ.

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

ENDF/B-VI 189.893 21.3127 168.580 2126.97

JENDL-3.2 188.621 20.9121 167.709 2201.37

JEF-2.2 182.526 1.95794 180.568 2130.64

CENDL-3.2 188.621 20.9121 167.709 2201.27

BROND-2 185.970 2.89895 183.071 2176.12

Mughabghab et al. \[Mu84\] 21.01.5 168.43.5 127466

Kirouac G. J. et al \[Ki73\] 1988

Mowatt R. S. et al \[Mo71\] 166.413.0\*2

Bidinosti D. et al. \[Bi58\] 20050\*1

Schuman R. P. et al. \[Sc62\] 23524\*2 3220480

Stoughton R. W. et al \[St60\] 260\*1 2100

Cabell M. J \[Ca70\] 961.8\*2\*3 127466

Fenner N. C. et al \[Fe67\] 15415\*2 1420430

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

\*1) Spectrum averaged

\*2) Maxwellian averaged

\*3) Ground state

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

Figs: <http://www.nndc.bnl.gov/~sirakov/fp/fp21/htm/Pm147.htm#mt1>