38-Sr- 87 JAEA EVAL-AUG09 K.Shibata, A.Ichihara, S.Kunieda
DIST-MAY10 20091127
----JENDL-4.0 MATERIAL 3834
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
History
09-08 Evaluated by K. Shibata, A. Ichihara and S. Kunieda.
09-10 Compiled by K. Shibata.
MF= 1 General information
MT=451 Descriptive data and directory
MF= 2 Resonance parameters
MT=151 Resolved and unresolved resonance parameters
Resolved resonance region (MLBW formula) : below 14.08 keV
Evaluation of JENDL-2 was performed on the basis of the
measurements by Camarda et al./1/ and Musgrove et al./2/
Neutron widths were derived from the data of 2g*(neutron
width) and neutron capture areas. Neutron orbital angular
momentum L was assumed to be 0 for all resonance levels
except the 2nd level (L=1) at 35.27 eV. However, the values
of total spin J were unknown for all resonance levels. Thus,
target spin of 4.5 was adopted as J value. Average
radiation width of 180.4 meV was obtained by averaging the
given radiation widths. hHwever, this value was reduced to
110.72 meV so as to reproduce the neutron capture resonance
integral of 118+-30 barns given by Mughabghab et al./3/
A negative resonance was also added at -50 eV, and the
parameters were adjusted so as to reproduce the thermal
capture cross section of 16+-3 barns given by Mughabghab et
al.
For JENDL-3, the values of total spin J were tentatively
estimated with a random number method. Neutron widths were
modified on the basis of the estimated J-values. Radiation
width of the negative level was slightly adjusted so as to
reproduce the thermal capture cross section according to the
modification of the positive levels. Scattering radius was
taken from the graph (fig. 1, Part A) given by Mughabghab et
al.
In JENDL-4, the radiation width of the negative resonance
was changed to 145 meV.
Unresolved resonance region: 14.08 keV - 1 MeV
The parameters were obtained by fitting to the total and
capture cross sections calculated from POD /4/. The
unresolved parameters should be used only for self-shielding
calculation.
Thermal cross sections and resonance integrals at 300 K
----------------------------------------------------------
0.0253 eV res. integ. (*)
(barns) (barns)
----------------------------------------------------------
Total 2.3975E+01
Elastic 6.9382E+00
n,gamma 1.7037E+01 1.2139E+02
----------------------------------------------------------
(*) Integrated from 0.5 eV to 10 MeV.
MF= 3 Neutron cross sections
MT= 1 Total cross section
Calculated with POD code /4/.
MT= 2 Elastic scattering cross section
Obtained by subtracting non-elastic cross sections from total
cross sections.
MT= 3 Non-elastic cross section
Sum of partial non-elastic cross sections.
MT= 4,51-91 (n,n') cross section
Calculated with POD code /4/.
MT= 16 (n,2n) cross section
Calculated with POD code /4/.
MT= 22 (n,na) cross section
Calculated with POD code /4/.
MT= 28 (n,np) cross section
Calculated with POD code /4/.
MT= 32 (n,nd) cross section
Calculated with POD code /4/.
MT=102 Capture cross section
Calculated with POD code /4/.
MT=103 (n,p) cross section
Calculated with POD code /4/.
MT=104 (n,d) cross section
Calculated with POD code /4/.
MT=105 (n,t) cross section
Calculated with POD code /4/.
MT=106 (n,He3) cross section
Calculated with POD code /4/.
MT=107 (n,a) cross section
Calculated with POD code /4/.
MT=203 (n,xp) cross section
Calculated with POD code /4/.
MT=204 (n,xd) cross section
Calculated with POD code /4/.
MT=205 (n,xt) cross section
Calculated with POD code /4/.
MT=206 (n,xHe3) cross section
Calculated with POD code /4/.
MT=207 (n,xa) cross section
Calculated with POD code /4/.
MF= 4 Angular distributions of emitted neutrons
MT= 2 Elastic scattering
Calculated with POD code /4/.
MF= 6 Energy-angle distributions of emitted particles
MT= 16 (n,2n) reaction
Neutron spectra calculated with POD/4/.
MT= 22 (n,na) reaction
Neutron spectra calculated with POD/4/.
MT= 28 (n,np) reaction
Neutron spectra calculated with POD/4/.
MT= 32 (n,nd) reaction
Neutron spectra calculated with POD/4/.
MT= 51 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 52 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 53 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 54 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 55 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 56 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 57 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 58 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 59 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 60 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 61 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 62 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 63 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 64 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 65 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 66 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 67 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 68 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 69 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 70 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 71 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 72 (n,n') reaction
Neutron angular distributions calculated with POD/4/.
MT= 91 (n,n') reaction
Neutron spectra calculated with POD/4/.
MT= 203 (n,xp) reaction
Proton spectra calculated with POD/4/.
MT= 204 (n,xd) reaction
Deuteron spectra calculated with POD/4/.
MT= 205 (n,xt) reaction
Triton spectra calculated with POD/4/.
MT= 206 (n,xHe3) reaction
He3 spectra calculated with POD/4/.
MT= 207 (n,xa) reaction
Alpha spectra calculated with POD/4/.
MF=12 Gamma-ray multiplicities
MT= 3 Non-elastic gamma emission
Calculated with POD code /4/.
MF=14 Gamma-ray angular distributions
MT= 3 Non-elastic gamma emission
Assumed to be isotropic.
MF=15 Gamma-ray spectra
MT= 3 Non-elastic gamma emission
Calculated with POD code /4/.
***************************************************************
* Nuclear Model Calculations with POD Code /4/ *
***************************************************************
1. Theoretical models
The POD code is based on the spherical optical model, the
distorted-wave Born approximaiton (DWBA), one-component exciton
preequilibrium model, and the Hauser-Feshbach-Moldauer statis-
tical model. With the preequilibrim model, semi-empirical
pickup and knockout process can be taken into account for
composite-particle emission. The gamma-ray emission from the
compound nucleus can be calculated within the framework of the
exciton model. The code is capable of reading in particle
transmission coefficients calculated by separate spherical or
coupled-channel optical model code.
2. Optical model parameters
Neutrons:
Coupled-channel optical model parameters /5/
Protons:
Koning and Delaroche /6/
Deuterons:
Lohr and Haeberli /7/
Tritons:
Becchetti and Greenlees /8/
He-3:
Becchetti and Greenlees /8/
Alphas:
Lemos /9/ potentials modified by Arthur and Young /10/
3. Level scheme of Sr- 87
-------------------------
No. Ex(MeV) J PI
-------------------------
0 0.00000 9/2 +
1 0.38853 1/2 -
2 0.87334 3/2 -
3 1.22842 5/2 +
4 1.25395 5/2 -
5 1.74000 13/2 +
6 1.74200 3/2 +
7 1.77047 5/2 +
8 1.92049 7/2 +
9 2.11006 3/2 -
10 2.15350 11/2 +
11 2.16941 1/2 +
12 2.23570 7/2 +
13 2.26200 3/2 -
14 2.41452 3/2 -
15 2.42040 7/2 -
16 2.48800 7/2 -
17 2.53280 9/2 +
18 2.53630 11/2 -
19 2.53900 7/2 -
20 2.55000 7/2 +
21 2.55500 9/2 -
22 2.59600 13/2 -
-------------------------
Levels above 2.60600 MeV are assumed to be continuous.
4. Level density parameters
Energy-dependent parameters of Mengoni-Nakajima /11/ were used
----------------------------------------------------------
Nuclei a* Pair Esh T E0 Ematch Elv_max
1/MeV MeV MeV MeV MeV MeV MeV
----------------------------------------------------------
Sr- 88 11.476 2.558 -1.509 0.753 2.134 6.189 4.515
Sr- 87 12.367 1.287 -0.021 0.633 0.786 4.453 2.596
Sr- 86 11.310 2.588 0.767 0.818 0.770 8.345 3.056
Sr- 85 11.114 1.302 1.863 0.862 -1.338 8.278 1.794
Rb- 87 10.932 1.287 -0.777 0.871 -0.070 6.722 2.414
Rb- 86 9.932 0.000 0.007 0.898 -1.348 5.547 1.738
Rb- 85 10.720 1.302 1.529 0.855 -0.855 7.650 2.088
Kr- 85 11.890 1.302 0.718 0.695 0.285 5.433 2.637
Kr- 84 11.089 2.619 1.235 0.745 1.364 7.286 3.951
Kr- 83 11.668 1.317 2.381 0.710 -0.316 6.290 1.889
----------------------------------------------------------
5. Gamma-ray strength functions
M1, E2: Standard Lorentzian (SLO)
E1 : Generalized Lorentzian (GLO) /12/
6. Preequilibrium process
Preequilibrium is on for n, p, d, t, He-3, and alpha.
Preequilibrium capture is on.
References
1) H.Camarda et al., NCSAC-31, 40 (1970).
2) A.R.de L.Musgrove et al., Proc. Int. Conf. on Neutron
Physics and Nucl. Data for Reactors, Harwell 1978, 449.
3) S.F.Mughabghab et al., "Neutron Cross Sections, Vol. I,
Part A", Academic Press (1981).
4) A.Ichihara et al., JAEA-Data/Code 2007-012 (2007).
5) S.Kunieda et al., J. Nucl. Sci. Technol. 44, 838 (2007).
6) A.J.Koning, J.P.Delaroche, Nucl. Phys. A713, 231 (2003).
7) J.M.Lohr, W.Haeberli, Nucl. Phys. A232, 381 (1974).
8) F.D.Becchetti,Jr., G.W.Greenlees, "Polarization
Phenomena in Nuclear Reactions," p.682, The University
of Wisconsin Press (1971).
9) O.F.Lemos, Orsay Report, Series A, No.136 (1972).
10) E.D.Arthur, P.G.Young, LA-8626-MS (1980).
11) A.Mengoni, Y.Nakajima, J. Nucl. Sci. Technol. 31, 151
(1994).
12) J.Kopecky, M.Uhl, Nucl. Sci. Eng. 41, 1941 (1990).