94-Pu-242 AITEL+ Eval-Mar00 T.Murata,T.Kawano
DIST-MAR02 Rev4-May00 20000518
----JENDL-3.3 MATERIAL 9446
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
HISTORY
87-05 Evaluation was made by
T.Murata (NAIG): Cross sections above resonance region and
other quantities,
M.Kawai (NAIG): Resonance parameters.
89-02 FP Yields were added.
Compilation was made by T. Nakagawa (JAERI).
94-06 JENDL-3.2.
nu-p, nu-d and nu-total were modified.
Compiled by T.Nakagawa (NDC/JAERI)
00-02 JENDL-3.3. Evaluation was made by T. Murata (AITEL)
and T.Kawano(Kyushu Univ.) and compiled by O.Iwamoto
(NDC/JAERI).
***** Modified parts for JENDL-3.3 ********************
(2,151)
(3,2), (3,4), (3,16), (3,17), (3,37), (3,51-91)
(4,51-90)
(5,16), (5,17), (5,91), (5,455)
***********************************************************
MF=2 Resonance Parametres
MT=151 Resolved and unresolved resonance parameters
1) Resolved resonances(1.0E-05eV to 1.891keV)
Fourteen resonances were added to the high energy region of
JENDL-3.2 resonances.These resonance pareameters were obtained
from Mughabghab's book/1/ for resonance energy and neutron
width,capture width determined by a systematic study/2/ and
fission width to reproduce fission area data/3/. Some other
parameters in JENDL-3.2 were revised,such as capture width and
fission width by the same method described above.
2) Unresolved resonances(1.90 to 40keV)
Energy region of unresolved resonances were changed.
3) Thermal cross section and resonance integral
Calculated 2200-m/sec cross sections and resonance integrals
are shown in the following Table.
2200-m/sec(b) Res.Integ.(b)
Total 27.06 -
Elastic 8.30 -
Fission 0.00210 5.56
Capture 18.76 1130
MF=3 Neutron cross section
MT=2 Elastic scattering
Obtained by subtructing other cross sections from total cross
section.
MT=4 Total inelastic scattering
Sum of partial inelastic cross sections (MT=51 to MT=91).
MT=51-77,91 Partial inelastic scattering
The results of ECIS-88 calculation with the parameters of
Lagrange et al./4/ and the level scheme given in the following
Table were modified to include the competition with the fission
,caputure and other neutron emission;(n,2n),(n,3n) and (n,3n)
reactions. The cross section shape of the final continuum
inelastic scattering of JENDL-3.2 was revised in the higher
energy region.
Pu-242 Level Scheme/5/
(High spin levels are neglected)
------------------------------------------------
No. Energy(MeV) Spin-Parity Coupling
------------------------------------------------
G.S. 0.0 0+ yes
1 0.0445 2+ yes
2 0.1473 4+ yes
3 0.3064 6+ yes
4 0.5181 8+ no
5 0.7805 1- yes
6 0.8323 3- yes
7 0.927 5- yes
8 0.956 0+ no
9 0.9925 2+ no
10 1.0194 3- no
11 1.0392 1+ no
12 1.064 4- no
13 1.092 6+ no
14 1.102 2+ no
15 1.122 5- no
16 1.150 2- no
17 1.155 3- no
18 1.182 2+ no
19 1.357 5- no
20 1.401 0+ no
------------------------------------------------
Levels above 1.410MeV were assumed to be continuum.
MT=16,17,37 (n,2n),(n,3n)and (n,4n)
Calculated from neutron emission cross section and branching
ratios of these reaction channels. The neutron emission cross
section was obtained by subtructing the fission and capture
cross sections from compound nucleus formation cross sction
calculated with ECIS-88 code.The branching ratios were obtained
from the consistent calculation made by Konshin/6/.
MF=4 Angular Distributions of Secondary Neutrons
MT=51-77
For the coupled levels,calxculated results with ECIS-88 code
were adopted. For other levels, JENDL-3.2 evaluation adopted.
MF=5 Energy Distributions of Secondary Neutrons
MT=16,17,91
Calculated with pre-compound and multi-step evaporation
theory code EGNASH /7,8/.
MT=455 Delayed neutron spectrum.
Summation calculation made by Brady and England /9/ was
adopted.
REFERENCES
1) Mughabghab,S.F. "Neutron Cross Sections, vol.1,part B",
Academic Press(1984)
2) Murata,T. JAERI-Conf 99-002, p.138
3) Auchampaugh,G.F. et al. Nucl.Phys.A171(1971)31
Weigmann,J.A. et al. Nucl.Phys.A438(1985)333
4) Lagrange,CH. and Jary,J. NEANDC(E) 198"L" (1978).
5) Shurshikov,M.L. et al. Nucl.Data Sheets 45,509(1985)
6) Konshin,V.A.: JAERI-Research 95-010
7) Yamamuro N.: JAERI-M 90-006 (1990).
8) Young P.G. and Arthur E.D.: LA-6947 (1977).
9) Brady M.C. and England T.R.: Nucl. Sci. Eng., 103, 129(1989).
******************** JEDL-3.2 ************************************
94-Pu-242 NAIG Eval-Mar87 T.Murata, M.Kawai
Dist-Sep89 Rev2-Jun94
History
87-05 Evaluation was made by
T.Murata (NAIG): Cross sections above resonance region and
other quantities,
M.Kawai (NAIG): Resonance parameters.
89-02 FP Yields were added.
Compilation was made by T. Nakagawa (JAERI).
94-06 JENDL-3.2.
nu-p, nu-d and nu-total were modified.
Compiled by T.Nakagawa (NDC/JAERI)
***** Modified parts for JENDL-3.2 ********************
(1,452), (1,455), (1,456)
***********************************************************
MF=1 General Information
MT=451 Comment and dictionary
MT=452 Number of neutrons per fission
Sum of Nu-p nad Nu-d.
MT=455 Delayed neutrons per fission
Based on the experimental data by Evans et al./1/, and
systematics by Tuttle/2/, Benedetti et al./3/ and Waldo et
al./4/ Decay constants were evaluated by Brady and
England/5/.
MT=456 Prompt neutrons per fission
Based on systematics by Manero and Konshin/6/, and by
Howerton/7/.
MF=2 Resonance Parameters
MT=151 Resonance parameters
Resolved resonance parameters for MLBW ( 1.0E-5 eV to 1.15 keV)
Evaluation for JENDL-2 was modified on the basis of fission
cross section measurements by Weigmann et al. /8/
Res. Energies = BNL 325 (3rd) /9/
Neutron and capture widths = Poortmans et al. /10/,
Auchampaugh et al./11/
Fission widths = Weigmann et al. /8/
R = 9.9 fm
Average capture width = 0.0242 eV
Two negative resonances were added to reproduce 2200-m/s
cross sections recommended by Mughabghab /12/
Unresolved resonance parameters ( 1.15 to 40 keV)
Parameters were determined to reproduce cross sections
evaluated as described below.
Calculated 2200-m/s cross sections and resonance integrals
2200-m/s(b) res. integ.(b)
total 27.11 ----
elastic 8.32 ----
fission 0.00256 5.58
capture 18.79 1130
MF=3 Neutron Cross Sections
Below 40 keV, represented with resonance parameters.
MT=1 SIG-TOT
Below 6 keV : Experimental data of Young and Reeder /13/
were averaged over some keV energy interval.
Above 6 keV : Spline fitting to experimental data of
Kaeppeler et al. /14/ and Moore et al. /15/
MT=2 SIG-EL
Obtained by subtracting other cross sections from total.
MT=4 SIG-INEL
Sum of partial inelastic cross sections
MT=51-91 Partial SIG-INEL
Below 3 MeV : The results of statistical and coupled channel
calculation of Lagrange et al./16/ were adopted.
Above 3 MeV : Extrapolation of the values was made based
on DWBA calculation.
Level Scheme
No. Energy(MeV) Spin-Parity
G.S. 0.0 0 +
1 0.04285 2 +
2 0.141685 4 +
3 0.294314 6 +
4 0.4976 8 +
5 0.59736 1 -
6 0.64889 3 -
7 0.74232 5 -
8 0.8607 0 +
9 0.90032 2 +
10 0.93807 1 -
11 0.95887 2 -
12 0.9924 4 +
13 1.0018 3 -
14 1.0306 3 +
15 1.0375 4 -
16 1.0764 4 +
17 1.0895 0 +
18 1.1155 5 -
19 1.1370 2 +
20 1.1615 6 -
21 1.1778 3 +
22 1.223 2 +
23 1.2325 4 +
24 1.2408 1 -
25 1.2621 3 +
26 1.2820 3 -
27 1.30873 5 -
28 1.41079 0 +
Levels above 1.41079 MeV were assumed to be continuum.
MT=16,17,37 Sigmas of (n,2n), (n,3n) and (n,4n)
Given by multiplication of neutron emission cross section
and branching ratio to each reaction. The neutron emission
cross section was obtained by subtracting fission and
capture cross sections from reaction cross section
calculated with spherical optical model. The branching
ratio was calculated with the formalism given by Segev et
al./17/
MT=18 SIG-FISS
Below 100 keV : Shape of SIG-FISS determined on the fission
area data of Auchampaugh et al./18/ Then normalized to
the value of higher energy region.
Above 100 keV : Fisson ratio to U-235 was determined on the
experimental data of Behrens et al./19/ and multiplied by
U-235 fission cross section /20/.
MT=102 SIG-CAP
Energy region of 6 keV to 210 keV : Determined on the basis of
experimental data of Hochenbury et al./21/ and Wisshak and
Kaeppeler /22/.
Other energy region : Statistical calculation result with
CASTHY code /23/ was normalized to SIG-CAP in the region of
6 to 210 keV. Direct and collective capture processes were
included in high energy region using the value of U-238
given by Kitazawa et al./24/
** Parameters for the CASTHY code calculation
Spherical optical potential parameters
V=40. 1-0.05En , Ws=6.5+0.15En , Vso=7.0 (MeV)
r=1.32 , rs=1.38 , rso=1.32 (fm)
a=as=aso=0.47 (fm)
Level density parameters were determined to reproduce the
resonance level spacings and level scheme sum staircases.
MT=251 Mu-L
Assumed to be the same as that of Pu-240.
MF=4 Angular Distributions
The same distributions as Pu-240 were assumed, which were
determined as follows.
MT=2 DSIG-El
Spherical optical model calculation
MT=51 to 91 DSIG-Inel
For the 1st and 2nd levels the results of calculation of
Lagrange et al./16/ are available and their results were
adopted. For other levels, statistical plus DWBA calcu-
lations were made.
MF=5 Energy Distributions of Secondary Neutrons
MT=16,17 and 91
Distributions were calculated with PEGASUS/25/
MT=37
Evaporation spectrum was taken from JENDL-2
MT=18
Taken from JENDL-2. Temperature was estimated from Z**2/A
systematics by Smith et al. /26/
References
1) Evans,A.E. et al.: Nucl. Sci. Eng., 50, 80 (1973).
2) Tuttle,R.J.: INDC(NDS)-107/G+special, p.29 (1979),
3) Benedetti,G. et al.: Nucl. Sci. Eng., 80, 379 (1982).
4) Waldo,R. et al.: Phys. Rev., C23, 1113 (1981).
5) Brady,M.C. and England,T.R.: Nucl. Sci. Eng., 103, 129 (1989).
6) Manero,F. and Konshin,V.A.: At. Energy Rev.,10, 637 (1972).
7) Howerton,R.J.: Nucl. Sci. Eng., 62, 438 (1977).
8) Weigmann,H., Wartena,J.A. and Burkholz,C. : Nucl. Phys.,
A438, 333 (1985).
9) Mughabghab,S.F. and Garber,D.I. : BNL 325, 3rd Ed., vol. 1
(1973)
10) Poortmans,F. et al. : Nucl. Phys., A207, 342 (1973).
11) Auchmpaugh,G.F. and Bowman,C.D. : Phys. Rev., C7, 2085 (1973).
12) Mughabghab,S.F. : "Neutron Cross Sections", Vol. 1, part B,
Academic Press (1984).
13) Young,T.E. and Reeder,S.D. : Nucl. Sci. Eng., 40, 389 (1970).
14) Kaeppeler,F. et al. : Proc. of Meeting on Nuclear Data of
Higher Pu and Am Isotopeps For Reactor Application, p.49
(1978, BNL).
15) Moore,M.S. et al. : Proc. of Nuclear cross sections for
Technology, p.703 (1979, Knoxville).
16) Lagrange,Ch. and Jary,J. : NEANDC(E) 198"L" (1978).
17) Segev,M. et al. : Annals of Nucl. Energy, 5, 239 (1978).
18) Auchampaugh,G.F. et al. : Nucl. Phys., A171, 31 (1971).
19) Behrens,J.W. et al. : Nucl. Sci. Eng., 66, 433 (1978).
20) Matsunobu,H. et al. : Evaluation for JENDL-3 (1987).
21) Hockenbury,R.W. et al. : NBS Special Publication 425, Vol. 2,
p.584 (1975).
22) Wisshak,K. and Kaeppeler,F. : Nucl. Sci. Eng., 66, 363 (1978),
Nucl. Sci. Eng., 69, 39 (1979).
23) Igarasi,S. and Fukahori,T.: JAERI 1321 (1991).
24) Kitazawa,H. et al. : Nucl. Phys., A307, 1 (1978).
25) Iijima,S. et al. : JAERI-M 87-025, p.337 (1987).
26) Smith,A.B. et al.: ANL/NDM-50 (1979).
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