73-Ta-181 NAIG EVAL-MAR87 N.YAMAMURO
DIST-JAN09 20090105
----JEFF-311 MATERIAL 7328
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
*************************** JEFF-3.1.1 *************************
** **
** Original data taken from: JEFF-3.1 **
** **
******************************************************************
***************************** JEFF-3.1 *************************
** **
** Original data taken from: JENDL-3.3 **
** **
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HISTORY
76-03 The evaluation for JENDL-1 /1/ was made by H.Yamakoshi
(ship research institute) and JENDL-1 compilation group.
83-03 JENDL-1 data were adopted for JENDL-2 and extended to 20
mev. mf=5 was revised, and unresolved resonance parameters
were added by Y.Kikuchi (jaeri) /2/.
83-11 Comment data were added.
87-03 The evaluation for JENDL-3 was made by N.Yamamuro (naig).
Resonance parameters were added by new experimental data.
Neutron cross sections, except total and elastic scattering
cross sections, and energy distributions of secondary
neutrons and photons were calculated with gnash /3/ and
casthy /4/ codes.
94-02 JENDL-3.2.
Compiled by T.Nakagawa (ndc/jaeri)
***** Modified parts for JENDL-3.2 ********************
(12,102)
Data were determined from energy balance.
***********************************************************
02-02 JENDL-3.3
Compiled by K.Shibata (jaeri)
***** Modified parts for JENDL-3.3 ********************
(1,451) Updated
(3,1),(3,2) Re-calculated
(3,107) Revised below 500 keV
(3,251) Deleted
(4,2) Transformation matrix deleted.
(5,16-91) Distributions at threshold were changed.
**********************************************************
mf=1 General information
mt=451 Descriptive data and dictionary
mf=2 Resonance parameters
mt=151 Resolved and unresolved resonance parameters
Resolved parameters for MLBW formula
The energy region from 1.0e-5eV to 1.0 keV. Parameters were
taken from refs./5,6,7/ for positive resonances, and from
ENDF/B-IV for a negative resonance. The radiative width of
0.059ev was assumed for the resonance whose radiative width
was unknown.
Unresolved parameters
In the energy range from 1 to 100keV, parameters were
determined to reproduce the measured capture cross sections
/6,8/. The parameters are as follows,
R= 7.8 fm , Dobs= 4.2 eV , radiative width= 0.065 eV,
So= 1.7e-04 S1= 2.0e-05 S2= 2.3e-04 nl= 3
calculated 2200-m/sec cross sections and resonance integrals
2200-m/sec res. integ
elastic 5.65 b -
capture 20.67 b 660.43 b
total 26.32 b -
mf=3 Neutron cross sections
mt=1 Total
Evaluated from experimental data.
mt=2 Elastic scattering
(total cross section) - (reaction cross section)
mt=4,51-64,91 Inelastic scattering
Below 3 MeV,calculated with optical and statistical model
code casthy/4/, and above 3 MeV calculated with statistical
and preequilibrium model code gnash/3/. Wilmore-Hodgson's
optical-model potential parameters/9/ were used, which
reproduced the experimental nonelastic cross sections up to
15 MeV.
V=47.01-0.267E-0.00118E**2(MeV)
Ws=9.52-0.053E (MeV)
ro=1.268, as=0.66 (fm)
rs=1.241, as=0.48 (fm)
The level scheme was adopted from ref./10/.
no. energy (MeV) spin-parity
g.s. 0.0 7/2+
1 0.0062 9/2-
2 0.136 9/2+
3 0.159 11/2-
4 0.301 11/2+
5 0.338 13/2-
6 0.482 5/2+
7 0.495 13/2+
8 0.543 15/2-
9 0.615 1/2+
10 0.619 3/2+
11 0.717 15/2+
12 0.773 17/2-
13 0.965 17/2+
14 1.028 19/2-
Levels above 1.03MeV were assumed to overlapping.
Level density parameters used were as follows,
1/MeV pair-E T(MeV) E (MeV) spin-cutoff
Ta-178 22.5 0.0 0.54 4.2 13.0
Ta-179 22.0 0.4 0.53 4.2 18.0
Ta-180 22.5 0.0 0.54 4.2 13.0
Ta-181 22.0 0.73 0.52 4.3 29.0
Ta-182 21.8 0.0 0.56 4.3 13.0
mt=16 (n,2n) cross section
Calculated with gnash/3/.
mt=17 (n,3n) cross section
Calculated with gnash/3/.
mt=28 (n,n p) cross section
Calculated with gnash /3/.
mt=102 Radiative capture cross section
Calculated with casthy/4/.
mt=103 (n.p) cross section
Calculated with gnash/3/.
mf=4 Angular distributions of secondary neutrons
mt=2 Calculated with casthy/4/.
mt=16,17,28
Isotropic in the laboratory system was assumed.
mt=51-64,91
Calculated with casthy/4/.
mf=5 Energy distributions of secondary neutrons
mt=16,17,28,91
Calculated with gnash/3/.
mf=12 Photon production multiplicities (option1)
mt=51-64.91,16,17,28,103
Calculated with gnash/3/.
mt=102
Rrom energy balance.
mf=14 Photon angular distributions
Isotropic in the center-of-mass system was assumed.
mf=15 Continuous photon energy spectra
mt=91,16,17,28,102,103
Calculated with gnash/3/.
References
1) Igarasi,S. et al.: JAERI 1261 (1979)
2) (Ed.) Nakagawa,T.: JAERI-M 84-103 (1984)
3) Young,P.G. and Arthur,E.D.: "GNASH, A Preequilibrium
Statistical Nuclear-Model Code for Calculation of Cross
Sections and Emission Spectra", LA-6974 (1977).
4) Igarasi,S. and Fukahori,T.: JAERI 1321 (1991).
5) Mughabghab,S.F, and Garder,D.I.: BNL325, 3rd ed. (1973).
6) Macklin,R,L,: Nucl,Sci,Eng., 86,362 (1984).
7) Tsubone,I., Nakajima,Y. and Kanda,Y.: Private communication
8) Yamamuro,N., Saito,K., Emoto,T., Wada,t., Fujita,Y. and
Kobayashi,K.: J.Nucl.Sci.Technol., 17, 582 (1980).
9) Wilmore,D. and Hodgson,P.E.: Nucl, Phys., 55, 673 (1964).
10) Firestone,R.B.: Nucl, Data Sheets 43, 289 (1984).
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