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5-B - 10 LANL EVAL-NOV89 G.M.HALE, P.G.YOUNG
DIST-JAN09 20090105
----JEFF-311 MATERIAL 525
-----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 *************************
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** Original data taken from: JEFF-3.0 **
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DATA TAKEN FROM :- ENDF/B-VI.3 (DIST-SEP91 REV1-JUL91)
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MOD1 OF ENDF/B-VI
The following revisions were made for MOD1 of ENDF/B-VI:
1. MF=1,MT=451 - Comments were added regarding estimated
(expanded) covariance for the Standards Cross Sections.
2. MF=3,MT=55,57,62,64,65,68,70,71,73,74,76-81,83,84 - LR flags
and Q-values corrected.
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ENDF/VI EVALUATION
G. M. Hale and P. G. Young
MAJOR CHANGES FROM VERSION V OF ENDF/B ARE:
1. Inclusion of the ENDF/B-VI standard (n,alpha) and (n,alpha1)
results from the simultaneous standards analysis (Ca85) over
the standard energy range thermal to 100 keV.
2. Replacement of all major cross sections and elastic angular
distributions from 10-5 eV to 1 MeV with results from the
R-matrix analysis performed in conjunction with the
simultaneous standards analysis.
3. Replaced the total cross section 1-20 MeV with results
from a covariance analysis of available data.
4. Revised elastic and inelastic cross sections for low-lying
levels incorporating new elastic, inelastic, and (n,xgamma)
experimental data. We attempted to better reconcile the
inelastic and gamma ray data.
5. Refit all elastic angular distributions from 1-20 MeV with
Legendre expansions and incorporated results from new
measurements.
6. Fit inelastic neutron angular distributions for first 5
excited states of B10 with Legendre expansions.
7. Incorporated new (n,t2alpha) cross section data into MT113
and adjusted (n,alpha) cross sections above standard region
for better consistency with data as well as other cross
sections (esp. total and elastic) determined by data.
*****Note that covariance data will be added at a later date.
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STANDARDS COVARIANCES
Phase 1 reviewers of the ENDF/B-VI standards cross sections have
expressed the concern that the uncertainties resulting from the
combination of R-matrix and simultaneous evaluations might have
led to uncertainties that are too small. As a result, the
Standards Subcommittee produced (at the May, 1990 CSEWG meeting)
a set of expanded covariance estimates for the standard cross
section reactions. These uncertainties are estimates such that
if a modern day experiment were performed on a given standard
cross section using the best techniques, approximately 2/3 of
the results should fall within these expanded uncertainties. The
expanded uncertainties for the B-10(n,alpha0) and B-10(n,alpha1)
cross sections are given in the following tables and are
compared to values from the combined output of the standards
covariance analysis:
B-10(n,alpha0) Cross Section
Energy Range Estimated Uncertainty Combined Analysis
(keV) (percent) (percent)
1.0E-08 - 0.1 0.5 0.21
0.1 - 5.0 1.5
5.0 - 30. 3.0 0.38
30. - 90. 5.0
90. - 150 10.0 0.86
150 - 200 12.0
200 - 250 15.0 0.79
B-10(n,alpha1) Cross Section
Energy Range Estimated Uncertainty Combined Analysis
(keV) (percent) (percent)
1.0E-08 - 0.1 0.2 0.16
0.1 - 5.0 0.4
5.0 - 30. 0.6 0.20
30. - 90. 1.0
90. - 150 1.5 0.48
150 - 200 2.0
200 - 250 2.5 0.62
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mf=2 --------- resonance parameters ----------------------------
mt=151 effective scattering radius = 4.129038-13 cm
mf=3 --------- smooth cross sections ---------------------------
the 2200 m/s cross sections are as follows,
mt=1 sigma = 3842.146 barns
mt=2 sigma = 2.142435 barns
mt=102 sigma = 0.5 barns
mt=103 sigma = 0.000566 barns
mt=107 sigma = 3839.496 barns
mt=113 sigma = 0.0069993 barns
mt=600 sigma = 0.000566 barns
mt=800 sigma = 241.2677 barns
mt=801 sigma = 3598.228 barns
mt=1 total cross section
0 to 1 mev, calculated from r-matrix parameters obtained
from simultaneous standards analysis (ca85) used to
obtain the endf/b-vi standard cross sections.
1 to 20 mev, covariance analysis of measurements of di67,
ts62,fo61,co52,au79, and co54, constrained to match
r-matrix fit at 1 mev. glucs covariance analysis code
(he80) was used in the calculations.
mt=2 elastic scattering cross section
0 to 1 mev, calculated from the r-matrix parameters
described for mt=1. experimental elastic scattering data
included in the fit are those of as70 and la71.
1 to 6 mev, smooth curve through measurements of la71, po70,
sa88, and ho69, constrained to be consistent with total
and reaction cross section measurements.
6 to 14 mev, smooth curve through measurements of ho69,co69,
te62,va70, va65, sa88, and gl82. Note that the data of
sa88 above 9 MeV were discounted.
14 to 20 mev, optical model extrapolation from 14 mev data
mt=4 inelastic cross section
thres.to 20 mev, sum of mt=51-85
mt=51-61 inelastic cross sections to discrete states
mt=51 q=-0.717 mev mt=55 q=-4.774 mev mt=59 q=-5.923 mev
52 -1.740 56 -5.114 60 -6.029
53 -2.154 57 -5.166 61 -6.133
54 -3.585 58 -5.183
thres.to 20 mev, based on (n,nprime) measurements of po70,
co69,ho69,va70,sa88, and gl82, and the (n,xgam) measure-
ments of da56,da60,ne70, and di88, using a gamma-ray
decay scheme from analysis of aj88. hauser-feshbach
calculations were used to estimate shapes and relative
magnitudes where experimental data were lacking.
mt=62-85 inelastic cross sections to groups of levels in
0.5-mev wide bands centered about the q-values given
below (used in lieu of mt=91 and file 5)
mt=62 q=-6.5 mev mt=70 q=-10.5 mev mt=78 q=-14.5 mev
63 -7.0 71 -11.0 79 15.0
64 -7.5 72 -11.5 80 15.5
65 -8.0 73 -12.0 81 16.0
66 -8.5 74 -12.5 82 16.5
67 -9.0 75 -13.0 83 17.0
68 -9.5 76 -13.5 84 17.5
69 -10.0 77 -14.0 85 18.0
thres. to 20 mev, integrated cross section obtained by sub-
tracting the sum of mt=2,51-61,103,104,107,and 113 from
mt=1. cross section distributed among the bands with
an evaporation model using a nuclear temperature given
by t=0.9728*sqrt(en) in mev,taken from ir67.
mt=102 (n,gamma) cross section
0 to 1 mev, assumed 1/v dependence with thermal value of
0.5 barn.
1 to 20 mev, assumed negligable, set equal to zero.
mt=103 (n,p) cross section
thres.to 20 mev, sum of mt=600-605
mt=104 (n,d) cross section
thres. to 20 mev, based on be9(d,n)b11 measurements of si65
and ba60, and the (n,d) measurement of va65.
mt=107 (n,alpha) cross section
0 to 20 mev, sum of mt=800,801.
mt=113 (n,t2alpha) cross section
0 to 2.3 mev, based on a single-level fit to the resonance
measured at 2 mev by da61, assuming l=0 incoming neu-
trons and l=2 outgoing tritons. the thermal measure-
ment (7+-2 mb) of ka87 was included in the analysis.
2.3 to 20 mev, smooth curve through measurements of fr56,
wy58, qa88, following general shape of da61 measurement
from 4 to 9 mev. we assumed that the experimental data
of qa88 supercedes reference qa85.
mt=600-605 (n,p) cross section to discrete levels
0 to 20 mev, crudely estimated from the calculations
of po70 and the (n,xgamma) measurements of ne70. cross
section for mt=600 assumed similar to mt=113 below
1 mev. gamma-ray decay scheme for be-10 from aj88.
mt=800 (n,alpha0) cross section
0 to 1 mev, calculated from the r-matrix parameters
described for mt=1. experimental (n,alpha0) data input
to the fit were those of ma68 and da61. in addition, the
angular distributions of va72 for the inverse reaction
were included in the analysis.
1 to 20 mev, based on da61 measurements, with smooth extra-
polation from 8 to 20 mev using 14-MeV data of an69. The
da61 data above approximately 2 mev were renormalized
by a factor of approximately 1.4. Note that some of the
structure seen in da61 was expanded to give consistent
nonelastic, elastic, and total cross sections when
compared with experimental data.
mt=801 (n,alpha1) cross section
0 to 1 mev, calculated from the r-matrix parameters
described for mt=1. experimental (n,alpha1) data in-
cluded in the fit are those of sc76. in addition, the
absolute differential cross-section measurements of
se76 were included in the analysis.
1 to 20 mev, smooth curve through measurements of da61 and
ne70, with smooth extrapolation from 15 to 20 mev. the
da61 data above approximately 2 mev were renormalized
by a factor of approximately 1.4. Note that some of the
structure seen in da61 was expanded to give consistent
nonelastic, elastic, and total cross sections when
compared with experimental data.
mf=4---------- neutron angular distributions -------------------
mt=2 elastic angular distributions
0 to 1 mev, calculated from the r-matrix parameters
described for mf=1,mt=1. experimental angular distri-
butions input to the fit for both the elastic scatter-
ing cross section and polarization were obtained from
available measurements.
1 to 14 mev, smoothed representation of legendre coeffi-
cients derived from the measurements of la71, ha73,
po70, ho69, co69, va69, va65, sa88, gl82, constrained
to match the r-matrix calculations at en=1 mev.
14 to 20 mev, optical model extrapolation of 14-mev data
mt=51 inelastic angular distribution to first level
thres. to 12 mev, fit Legendre expansions to exp. data of
Po70, Gl82, and Sa88.
12 - 20 MeV, assumed similar distribution as 12 MeV.
mt=52-55 inelastic angular distribution to first level
thres. to 12 mev, fit Legendre expansions to exp. data of
Sa88.
12 - 20 MeV, assumed similar distribution as 12 MeV.
mt=56-85 inelastic angular distributions
thres. to 20 mev, assumed isotropic in center of mass
mf=12 -------- gamma ray multiplicities ------------------------
mt=102 capture gamma rays
0 to 20 mev, capture spectra and transition probabilities
derived from the thermal data of th67, after slight
changes in the probabilities and renormalization to the
energy levels of aj75. the lp flag is used to conserve
energy and to reduce significantly the amount of data
required in the file. except for the modification due
to the lp flag, the thermal spectrum is used over the
entire energy range.
mt=801 0.4776-mev photon from the (n,alpha1) reaction
0 to 20 mev, multiplicity of 1.0 at all energies
mf=13 -------- gamma-ray production cross sections -------------
mt=4 (n,ngamma) cross section
thres. to 20 mev, obtained from mt=51-60 using b-10 decay
scheme obtained from aj88.
mt=103 (n,pgamma) cross sections
thres. to 20 mev, obtained from mt=601-605 using be-10
decay scheme deduced from aj88.
mf=14 -------- gamma ray angular distributions -----------------
mt=4 (n,ngamma) angular distributions
thres. to 20 mev, assumed isotropic
mt=102 (n,gamma) angular distributions
0 to 20 mev, assumed isotropic.
mt=103 (n,pgamma) angular distributions
thres. to 20 mev, assumed isotropic
mt=801 (n,alpha1/gamma) angular distribution
0 to 20 mev, assumed isotropic
----------------------- references -----------------------------
aj75 f. ajzenberg-selove, nucl. phys. a248,6 (1975)
aj88 f. ajzenberg-selove, nucl. phys. a490,1 (1988)
an69 B. Antolkovic, Nuc.Phys.A139, 10 (1969).
as70 a. asami and m.c. moxon, j.nucl.energy 24,85 (1970)
au79 g.auchampaugh et al., nucl.sci.eng.69,30(1979)
ba60 r.bardes and g.e. owen, phys.rev.120,1369 (1960)
be56 r.l. becker and h.h. barschall, phys.rev.102,1384 (1956)
bo51 c.k.bockelman et al., phys.rev. 84,69 (1951)
bo69 d.bogart and l.l.nichols, nucl.phys.a125,463 (1969)
ca85 a.carlson et al., nuc.data for basic & applied science,
santa fe, nm (1985) p.1429.
co52 j.h.coon et al., phys.rev. 88,562 (1952)
co54 c.f.cook and t.w. bonner,phys.rev. 94,651 (1954)
co67 s.a. cox and f.r. pontet, j.nucl.energy 21,271 (1967)
co69 j.a. cookson and j.g.locke,nucl.phys.a146,417(1970)
co73 m.s. coates et al., priv. comm. to l.stewart (1973)
da56 r.b.day,phys.rev.102,767 (1956)
da60 r.b. day and m.walt,phys.rev.117,1330 (1960)
da61 e.a. davis et al., nucl.phys.27,448 (1961)
di67 k.m. diment, aere-r-5224 (1967)
di88 j.k.dickens, proc.conf. on nuc.data for sci.& tech.,mito,
japan (1988) p.213.
fo61 d.m. fossan et al., phys.rev. 123,209 (1961)
fr56 g.m. frye and j.h. gammel,phys.rev. 103,328 (1956)
gl82 s.glendinning, nuc.sci.eng.80,256(1982)
ha73 s.l.hausladen, thesis, ohio univ. coo-1717-5 (1973)
he80 d.hetrick & c.y.fu, ornl/tm-7341 (1980).
hy69 m.hyakutake, eandc(j)-13 (1969) p.29
ho69 j.c. hopkins, priv. comm. lasl (1969)
ir67 d.c.irving, ornl-tm-1872 (1967)
ka87 R.Kavanagh & R.Marcley, Phys.Rev.C36, 1194 (1987).
la71 r.o. lane et al., phys.rev.c4,380 (1971)
ma68 r.l.macklin and j.h.gibbons,phys.rev.165,1147 (1968)
mo66 f.p.mooring et al.,nucl.phys.82,16 (1966)
ne54 n.g.nereson,la-1655 (1954)
ne70 d.o.nellis et al., phys.rev. c1,847 (1970)
po70 d.porter et al., awre o 45/70 (1970)
qa85 S.Qaim et al., Santa Fe Conf. (1985)p.97.
qa88 S.Qaim et al., Mito Conf. (1988) p.225.
sa88 E.T. Sadowski, Ph.D thesis, Ohio U., (Nov.,1988).
sc76 r.a. schrack et al., proc.icinn(erda-conf-760715-p2),1345
(1976)
se76 r.m. sealock and j.c. overley, phys.rev.c13,2149 (1976)
si65 r.h.siemssen et al., nucl.phys.69,209 (1965)
sp73 r.r. spencer et al., eandc(e)147,al (1973)
te62 k.tesch, nucl.phys.37,412 (1962)
th67 g.e. thomas et al., nucl.instr.meth.56,325 (1967)
ts63 k.tsukada and o.tanaka,j.phys.soc.japan 18,610 (1963)
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va70 b.vaucher et al.,helv.phys.acta 43,237 (1970)
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wy58 m.e. wyman et al., phys.rev.112,1264 (1958)
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