37-Rb- 87 JAEA EVAL-AUG09 K.Shibata, A.Ichihara, S.Kunieda
DIST-MAY10 20091118
----JENDL-4.0 MATERIAL 3731
-----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 12.46 keV
Resonance parameters of JENDL-2 were modified as follows :
Evaluation of JENDL-2 was performed on the basis of the data
measured by Ohkubo et al./1/ Among 30 levels measured in
the energy region up to 49 keV, 28 levels were assumed to be
s-wave, and remaining 2 levels at 267.1 and 376.9 eV to be
p-wave. Neutron widths were determined from the 2g*(neutron
width) measured by Ohkubo et al. However, the value of
total spin J for each resonance level was unknown except
only 6 levels assigned by Ohkubo et al. The target spin of
1.5 was adopted for these unknown levels instead of J.
Radiation width was obtained to be 166+-8 meV for only one
resonance level at 376.9 eV from the measurement by Ohkubo
et al. Average radiation width was also estimated to be
166+-30 meV by Ohkubo et al., and was adopted for the other
levels.
For JENDL-3, the total spin J of 24 resonance levels was
tentatively estimated with a random number method. Neutron
widths of these levels were modified on the basis of the
estimated J-values. Radiation width of the 2nd level at
376.9 eV and average radiation width were also modified to
115.33 and 115.0 meV, respectively, so as to reproduce the
thermal capture cross section of 120+-30 mb given
by Mughabghab et al./2/ Scattering radius was taken from
the graph (Fig. 1, part A) given by Mughabghab et al.
No modification was performed for JENDL-4.0.
Unresolved resonance region: 12.46 keV - 1 MeV
The parameters were obtained by fitting to the total and
capture cross sections calculated from POD /3/. 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 4.5049E+00
Elastic 4.3849E+00
n,gamma 1.2004E-01 2.7200E+00
----------------------------------------------------------
(*) Integrated from 0.5 eV to 10 MeV.
MF= 3 Neutron cross sections
MT= 1 Total cross section
Calculated with POD code /3/.
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 /3/.
MT= 16 (n,2n) cross section
Calculated with POD code /3/.
MT= 17 (n,3n) cross section
Calculated with POD code /3/.
MT= 22 (n,na) cross section
Calculated with POD code /3/.
MT= 28 (n,np) cross section
Calculated with POD code /3/.
MT= 32 (n,nd) cross section
Calculated with POD code /3/.
MT=102 Capture cross section
Calculated with POD code /3/.
MT=103 (n,p) cross section
Calculated with POD code /3/.
MT=104 (n,d) cross section
Calculated with POD code /3/.
MT=105 (n,t) cross section
Calculated with POD code /3/.
MT=106 (n,He3) cross section
Calculated with POD code /3/.
MT=107 (n,a) cross section
Calculated with POD code /3/.
MT=203 (n,xp) cross section
Calculated with POD code /3/.
MT=204 (n,xd) cross section
Calculated with POD code /3/.
MT=205 (n,xt) cross section
Calculated with POD code /3/.
MT=206 (n,xHe3) cross section
Calculated with POD code /3/.
MT=207 (n,xa) cross section
Calculated with POD code /3/.
MF= 4 Angular distributions of emitted neutrons
MT= 2 Elastic scattering
Calculated with POD code /3/.
MF= 6 Energy-angle distributions of emitted particles
MT= 16 (n,2n) reaction
Neutron spectra calculated with POD/3/.
MT= 17 (n,3n) reaction
Neutron spectra calculated with POD/3/.
MT= 22 (n,na) reaction
Neutron spectra calculated with POD/3/.
MT= 28 (n,np) reaction
Neutron spectra calculated with POD/3/.
MT= 32 (n,nd) reaction
Neutron spectra calculated with POD/3/.
MT= 51 (n,n') reaction
Neutron angular distributions calculated with POD/3/.
MT= 52 (n,n') reaction
Neutron angular distributions calculated with POD/3/.
MT= 53 (n,n') reaction
Neutron angular distributions calculated with POD/3/.
MT= 54 (n,n') reaction
Neutron angular distributions calculated with POD/3/.
MT= 55 (n,n') reaction
Neutron angular distributions calculated with POD/3/.
MT= 56 (n,n') reaction
Neutron angular distributions calculated with POD/3/.
MT= 57 (n,n') reaction
Neutron angular distributions calculated with POD/3/.
MT= 58 (n,n') reaction
Neutron angular distributions calculated with POD/3/.
MT= 59 (n,n') reaction
Neutron angular distributions calculated with POD/3/.
MT= 60 (n,n') reaction
Neutron angular distributions calculated with POD/3/.
MT= 61 (n,n') reaction
Neutron angular distributions calculated with POD/3/.
MT= 62 (n,n') reaction
Neutron angular distributions calculated with POD/3/.
MT= 63 (n,n') reaction
Neutron angular distributions calculated with POD/3/.
MT= 64 (n,n') reaction
Neutron angular distributions calculated with POD/3/.
MT= 65 (n,n') reaction
Neutron angular distributions calculated with POD/3/.
MT= 66 (n,n') reaction
Neutron angular distributions calculated with POD/3/.
MT= 91 (n,n') reaction
Neutron spectra calculated with POD/3/.
MT= 203 (n,xp) reaction
Proton spectra calculated with POD/3/.
MT= 204 (n,xd) reaction
Deuteron spectra calculated with POD/3/.
MT= 205 (n,xt) reaction
Triton spectra calculated with POD/3/.
MT= 206 (n,xHe3) reaction
He3 spectra calculated with POD/3/.
MT= 207 (n,xa) reaction
Alpha spectra calculated with POD/3/.
MF=12 Gamma-ray multiplicities
MT= 3 Non-elastic gamma emission
Calculated with POD code /3/.
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 /3/.
***************************************************************
* Nuclear Model Calculations with POD Code /3/ *
***************************************************************
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 /4/
Protons:
Koning and Delaroche /5/
Deuterons:
Lohr and Haeberli /6/
Tritons:
Becchetti and Greenlees /7/
He-3:
Becchetti and Greenlees /7/
Alphas:
Lemos /8/ potentials modified by Arthur and Young /9/
3. Level scheme of Rb- 87
-------------------------
No. Ex(MeV) J PI
-------------------------
0 0.00000 3/2 -
1 0.40259 5/2 -
2 0.84544 1/2 -
3 1.34938 7/2 +
4 1.38982 3/2 -
5 1.46300 1/2 -
6 1.57801 3/2 -
7 1.57810 9/2 +
8 1.74058 5/2 -
9 1.89300 1/2 -
10 1.95000 3/2 +
11 2.01300 5/2 -
12 2.28400 3/2 -
13 2.37841 5/2 +
14 2.37900 3/2 +
15 2.39700 1/2 -
16 2.41446 3/2 -
-------------------------
Levels above 2.42446 MeV are assumed to be continuous.
4. Level density parameters
Energy-dependent parameters of Mengoni-Nakajima /10/ were used
----------------------------------------------------------
Nuclei a* Pair Esh T E0 Ematch Elv_max
1/MeV MeV MeV MeV MeV MeV MeV
----------------------------------------------------------
Rb- 88 10.406 0.000 -0.431 0.771 -0.492 3.809 1.916
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- 87 12.111 1.287 -0.112 0.649 0.793 4.518 3.172
Kr- 86 11.310 2.588 -0.507 0.715 2.085 6.130 3.575
Kr- 85 11.890 1.302 0.718 0.695 0.285 5.433 2.637
Br- 85 10.720 1.302 -0.138 0.819 0.183 6.155 1.944
Br- 84 11.060 0.000 0.608 0.898 -2.409 6.862 0.408
Br- 83 10.507 1.317 1.382 0.813 -0.276 6.734 2.134
----------------------------------------------------------
5. Gamma-ray strength functions
M1, E2: Standard Lorentzian (SLO)
E1 : Generalized Lorentzian (GLO) /11/
6. Preequilibrium process
Preequilibrium is on for n, p, d, t, He-3, and alpha.
Preequilibrium capture is on.
References
1) M.Ohkubo et al, J. Nucl. Sci. Tech. 21, 254 (1984).
2) S.F.Mughabghab et al., "Neutron Cross Sections, Vol. I,
Part A", Academic Press (1981).
3) A.Ichihara et al., JAEA-Data/Code 2007-012 (2007).
4) S.Kunieda et al., J. Nucl. Sci. Technol. 44, 838 (2007).
5) A.J.Koning, J.P.Delaroche, Nucl. Phys. A713, 231 (2003).
6) J.M.Lohr, W.Haeberli, Nucl. Phys. A232, 381 (1974).
7) F.D.Becchetti,Jr., G.W.Greenlees, "Polarization
Phenomena in Nuclear Reactions," p.682, The University
of Wisconsin Press (1971).
8) O.F.Lemos, Orsay Report, Series A, No.136 (1972).
9) E.D.Arthur, P.G.Young, LA-8626-MS (1980).
10) A.Mengoni, Y.Nakajima, J. Nucl. Sci. Technol. 31, 151
(1994).
11) J.Kopecky, M.Uhl, Nucl. Sci. Eng. 41, 1941 (1990).