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

**51-Sb-124 Review**

Drafted by ZHUANG Youxiang, CNDC, October 27, 2003

# Files

**ENDF/B-VI:** Year of origin 1974, taken from ENDF/B-V, no revisions
since then

**JEF-2:** Year of origin 1982, data taken mostly from ENDF/B-V, last
revision 1990

**JENDL-3:** Year of origin 1990, last revision 1990

# Thermal and resonance region

**ENDF/B-VI: No** resonance parameters given, except AP; scattering

radius 6.0149 fm.

**JEF-2: No** resonance parameters given, except AP; scattering

radius 6.0149 fm.

.

**JENDL-3:** No resolved resonance parameters given, scattering radius

5.7 fm, unresolved resonance region from 2.54 eV to 100 keV (Table 1).

**Recommendation/Conclusion:** **JENDL-3** recommended in thermal and
resonance

region up to 100 keV.

# Fast neutron region

·Methodology

**ENDF/B-VI, JEF-2:** Spherical OM for MT=1; capture from NCAP code;
inelastic cross sections

(MF=3, MT=4, 51-91) from COMNUC-3 code, no pre-equilibrium corrections.
MT=1, 2, 4,

51-58, 91, 102. **JEF-2** added**:** 103\~105, 107.

**JENDL-3:** Spherical OM and statistical model code CASTHY for MT=1, 4,
51-91, 102 by

taking into account competing reactions MT=16, 17, 103, 107 calculated
with the pre-equilibrium

and multi-step evaporation model code PEGASUS. Direct and semi-direct
capture estimated;

elastic calculated as (MT1 -- sum of partial cross sections); Legendre
coefficients from CASTHY

to get unisotropic angular distribution for MF=4, MT=2 in CM system.
MT=1, 2, 4, 16, 17, 22, 28, 32,33,

51, 91, 102\~105, 107.

·MT=16, 17, 22, 28, 32,33

**JENDL-3:**.has a complete data set, including MT=16, 17, 22, 28,
32,33.

**Recommendation/Conclusion:** **JENDL-3** recommended in fast energy
region

100 keV - 20 MeV. The shape of (n,inl) cross section is reasonable.

**Table 1.** Summary for Resolved and Unresolved Resonance Region:
Sb-124

+---------+-----+-------------+------+-----+-------------------------+
| Library | Y   | First       | RRR  | URR | Remarks                 |
|         | ear | Authors     |      |     |                         |
+---------+-----+-------------+------+-----+-------------------------+
| EN      | 1   | Schenter,   |      |     |                         |
| DF/B-VI | 974 |             |      |     |                         |
|         |     | Schmittroth |      |     |                         |
|         |     |             |      |     |                         |
|         |     | (NNDC)      |      |     |                         |
+---------+-----+-------------+------+-----+-------------------------+
| JEF-2   | 1   | Scientific  |      |     |                         |
|         | 982 |             |      |     |                         |
|         |     | Co          |      |     |                         |
|         |     | -ordination |      |     |                         |
|         |     |             |      |     |                         |
|         |     | Group       |      |     |                         |
|         |     |             |      |     |                         |
|         |     | (NEA)       |      |     |                         |
+---------+-----+-------------+------+-----+-------------------------+
| JENDL-3 | 1   | JNDC FP     |      | 2   | URR parameters from     |
|         | 990 |             |      | .54 | 2.54 eV to 100 keV were |
|         |     | Nuclear     |      | e   | newly evaluated.        |
|         |     | Data        |      | V\~ |                         |
|         |     |             |      |     |                         |
|         |     | Working     |      | 100 |                         |
|         |     |             |      | keV |                         |
|         |     | Group       |      |     |                         |
+---------+-----+-------------+------+-----+-------------------------+

**Table 2.** Thermal Cross Sections for Sb-124

+---------------------------+-------------+-------------+-------------+
| Library / Experiment      | Total       | Capture     | Elastic     |
+---------------------------+-------------+-------------+-------------+
| ENDF/B-VI                 | 11.046 b    | 6.5 b       | 4.546 b     |
+---------------------------+-------------+-------------+-------------+
| JEF-2                     | 11.046 b    | 6.5 b       | 4.546 b     |
+---------------------------+-------------+-------------+-------------+
| JENDL-3                   | 21.16 b     | 17.40 b     | 3.76 b      |
+---------------------------+-------------+-------------+-------------+
| BNL-325 (1981)            |             |             |             |
+---------------------------+-------------+-------------+-------------+
| S.F.Mughabghab,           |             |             |             |
| INDC(NDS)-424,            |             |             |             |
|                           |             |             |             |
| p.72 (2001)               |             |             |             |
+---------------------------+-------------+-------------+-------------+