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5-B - 11 LANL EVAL-MAY89 P.G.YOUNG
DIST-JAN09 20090105
----JEFF-311 MATERIAL 528
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
*************************** JEFF-3.1.1 *************************
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** Original data taken from: JEFF-3.1 **
** **
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***************************** JEFF-3.1 *************************
** **
** Original data taken from: ENDF/B-VI.8 **
** **
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FILE INFORMATION
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ENDF/B-VI MOD 2 Revision, July 2000, S. Frankle, J. Campbell,
R. Little (LANL)
The evaluation was modified so that the threshold for the
(n,n'continuum) reaction, MT=91, was the same for the secondary
particle production as for the cross section. The threshold for
the secondary neutrons and photons was changed from 1.050000e+7
to 1.002700e+7 eV.
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ENDF/B-VI MOD 1 Evaluation, P.G. Young (LANL) May 1989
GENERAL DESCRIPTION
This evaluation is a synthesis of experimental results and
theoretical calculations using the GNASH Hauser-Feshbach,
statistical theory code [ar88, yo77]. It replaces a pre-1970 U.K.
evaluation that was adapted for ENDF/B in 1971 [co79].
Major emphasis was placed on experimental data where possible,
usually using the calculations to estimate shapes and
experimental data to normalize the the calculations. Spherical
optical model calculations were used to obtain particle
transmission coefficients, using global potentials for protons
and alphas, and the work of Dave et al. [Da83] for the neutron
potential. Gilbert-Cameron level density parameters were used
and preequilibrium corrections from an exciton model were
included. In general, the calculations were required for the
gamma and particle emission spectra from charged-particle
reactions, as well as for inelastic neutron and gamma emission
above the third excited state of B11, and for all states above
an incident neutron energy of about 8 MeV.
MF=2 RESONANCE PARAMETERS ***************************************
MT=151 scattering radius only.
MF=3 SMOOTH NEUTRON CROSS SECTIONS ******************************
THERMAL CROSS SECTIONS
The 1981 evaluation by Mughabghab [mu81] was used for the
2200 m/s cross sections, as follows:
MT = 1 sigma = 4.8455 b
MT = 2 sigma = 4.8400 b
MT =102 sigma = 0.0055 b
MT= 1 Total Cross Section. At low energies, evaluation by Mu81a
of thermal data used. At higher energies exp. data of
Mo66, La70, Ca73, Au79, Co52 & Co54 were used. The high
resolution data of Au79 were emphasized. Optical model
calculations with the Da83 potential used to define shape
above 14 MeV.
MT= 2 Elastic Cross Section. Based on exp. data of La70,
Wi55, Po70, Ne73, Wh80, Ko82, Ho69, Gl82, Co70 & Al69.
Optical model calculations with potential of Da83
used with renormalization above 14 MeV. Thermal eval.
of Mu81a used at low energies.
MT= 4 (n,nprime)gamma+(n,nprime)continuum. sum of mt=51-60,91.
MT= 16 (n,2n) Cross Section. Based entirely on GNASH analysis.
MT= 22 (n,na) Cross Section. Based entirely on GNASH analysis.
MT= 28 (n,np) Cross Section. Based entirely on GNASH analysis.
MT=51-54 (n,n'gamma) Cross Sections. Based on exp. data of
Au86, Gl82, Ho69, Po70, Co70, Ko82, Ba85. The Au86 data
shapes were used to establish low energy behavior.
MT=55-60 (n,n'gamma) Cross Sections. Shapes of excitation
curves calculated with GNASH. Absolute magnitudes obtain-
ed by renormalizing such that sum of all partials gave
reaction, elastic, total x/s consistent with avail. data.
MT= 91 (n,n'continuum) Cross Section. Based on GNASH calculation
entirely.
MT=102 (n,gamma) Cross Section. adopted from endf/b-v.1 except
thermal cross section of Mu81a used.
MT=103 (n,p) Cross Section. Based on GNASH calculation and exp.
data of Sc70a,Fl67, St65, etc.
MT=105 (n,t) Cross Section. Similar to endf/b-v data, with a
smooth curve passing thru exp. data of Wy58 at 14.1 MeV.
MT=107 (n,alpha) Cross Section. Based on GNASH calculation and
exp. data (An79, Sc70b,Ar56).
MF=4 NEUTRON ANGULAR DISTRIBUTIONS ******************************
MT= 2 legendre coefficients obtained by drawing smooth curve
through fitted coefficients from measurements listed
under mf3/mt2. data of La60,Gl79,Wh80,Ne73,Ho69,Hy74
emphasized. optical model calculations used above 14 mev.
MT=51-54 Legendre coefficients obtained by fitting exp.data,
especially Al69, Hy74, Po70, Ho69, Gl79 & Co69. Smooth
curves then passed through fitted coefficients.
MT=55-60 Isotropy assumed.
MF=6 ENERGY-ANGLE CORRELATED DISTRIBUTIONS **********************
MT= 16 Neutron and photon distributions are given based on
GNASH calculations described above to obtain spectra
and multiplicities. Kalbach-Mann (Ka81) systematics (KMS)
used for neutron angular distributions. Photon distri-
butions taken as isotropic.
MT= 22 Neutron and alpha distributions are based on KMS.
Photon distributions assumed isotropic. Multiplicities
and spectra based on GNASH calculations.
MT= 28 Neutron and proton distributions are based on KMS.
Photon distributions assumed isotropic. Multiplicities
and spectra based on GNASH calculations.
MT= 91 Neutron distributions based on KMS and isotropic photon
distributions given. Multiplicities and spectra obtained
from GNASH analysis.
MT=103 Proton distributions based on KMS and isotropic photon
distributions given. Multiplicities and spectra obtained
from GNASH analysis.
MT=107 Alpha distributions based on KMS and isotropic photon
distributions given. Multiplicities and spectra obtained
from GNASH analysis.
MF=12 PHOTON MULTIPLICITIES *************************************
MT=102 Radiative Capture Photon Yields obtained from theoretical
calculations (Mu81) based on Lane-Lynn Theory of Direct
Capture.
MF=13 PHOTON CROSS SECTIONS *************************************
MT= 4 gamma ray production cross sections from inelastic scat.
Obtained using discrete data (MF=3, MT=51-60) and photon
branching ratios (Aj85).
MF=14 PHOTON ANGULAR DISTRIBUTIONS ******************************
MT= 51 isotropy assumed at all energies.
MT=102 isotropy assumed for all gammas at all energies.
MF=33 NEUTRON CROSS SECTION COVARIANCES *************************
To be provided in the future.
REFERENCES ******************************************************
[Aj85] F.Ajzenberg-Selove, Nucl.Phys. A433, 1 (1985).
[Al69] J.Alder et al., Nuc.Phys. 147, 657 (1969).
[An79] B.Antolkovic et al., Nuc.Phys. A235, 189 (1979).
[Ar56] A.Armstrong et al., Phys.Rev. 103, 335 (1956).
[Ar88] E.Arthur, ICTP Workshop, Trieste (1988) [LA-UR 88-1753].
[Au79] G.Auchampaugh et al., Nucl.Sci.Eng. 69, 30 (1979).
[Au86] G.Auchampaugh & S.Wender, personal communcation (1986).
[Ba85] M.Baba et al., Santa Fe Nuc.Data Conf. (1985) p.223.
[Ca73] J.Cabe et al., report CEA-R-4524 (1973).
[Co52] J.Coon, Phys.Rev. 88, 562 (1952).
[Co54] C.Cook & T.Bonner, Phys.Rev. 94, 651 (1954).
[Co70] J.Cookson et al., Nucl.Phys. A146, 417 (1970).
[Co79] C.Cowan, Summary Documentation ENDF/B-V, ENDF-201 (1979).
[Da83] J.Dave & C.Gould, Phys.Rev. C28, 2212 (1983).
[Fl67] F.Flesch et al., Oest.Acad.Wiss. 176, 45 (1967).
[Gl82] S.Glendinning et al., Nucl.Sci.Eng. 80, 256 (1982).
[Ho69] J.Hopkins et al., Nucl.Sci.Eng. 36, 275 (1969).
[Hy74] M.Hyakutake et al., J.Nuc.Sci.Tech. 11, 407 (1974).
[Ka81] C.Kalbach & F.Mann, Phys.Rev. C23, 112 (1981).
[Ko83] P.Koehler et al., Nucl.Phys. A294, 221 (1983).
[La70] R.Lane et al., Phys.Rev.C 2, 2097 (1970).
[Mo66] F.Mooring et al., Nucl.Phys. 82, 16 (1966).
[Mu81a] S.F.Mughabghab et al., Neutron Res.Parameters and
Thermal Cross Sect., Vol.1, Academic Press (1981).
[Mu81b] S.F.Mughabghab, Proc.Conf.on Nuc.Data Eval.Meth. & Proc.
BNL-NCS-51363 (1981),V1,p.339.
[Ne73] C.Nelson et al., report COO-1717-8 (1973).
[Po70] D.Porter et al., report AWRE-O-45-70 (1970).
[Sc70a] Schantl, personal communication to NNDC (1970).
[Sc70b] W.Scobel et al., Z.Nat. A25, 1406 (1970).
[St65] J.Strain et al., Oak Ridge report ORNL-3672 (1965).
[Wh80] R.M.White et al., Nucl.Phys. A340, 13 (1980).
[Wi55] H.Willard et al., Phys.Rev. 98, 669 (1955).
[Wy58] M.Wyman, Phys.Rev. 112, 1264 (1958).
[Yo77] P.Young, E.Arthur, Los Alamos report LA-6947 (1977).
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***************** PROGRAM LINEAR (VERSION 89-1) *****************
DATA LINEARIZED TO WITHIN AN ACCURACY OF 0.300 PER-CENT
***************** PROGRAM FIXUP (VERSION 89-2) ******************
*RECONSTRUCTED MT NUMBERS
4 =+( 50, 91)
103 =+(600,649)
104 =+(650,699)
105 =+(700,749)
106 =+(750,799)
107 =+(800,849)
101 =+( 18, 18)+(102,116)
27 =+(101,101)
3 =+( 4, 5)+( 16, 17)+( 22, 37)+( 41, 42)
19 =+( 18, 18)-( 20, 21)-( 38, 38)
1 =+( 2, 3)
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