44-Ru- 99
44-Ru- 99 JNDC EVAL-Mar90 JNDC FP Nuclear Data W.G.
DIST-MAY10 20091217
----JENDL-4.0 MATERIAL 4434
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
HISTORY
90-03 New evaluation for JENDL-3 was completed by JNDC FPND
W.G./1/
93-10 JENDL-3.2 was made by JNDC FPND W.G.
01-04 Res. params were modified for JENDL-3.3.
09-12 Compiled by A.Ichihara.
***** Modified parts for JENDL-3.3 ********************
(2,151) Resolved resonance parameters (J-values)
***********************************************************
***** Modified parts for JENDL-4.0 ********************
(2,151) Unresolved resonance parameters were updated.
***********************************************************
MF = 1 General information
MT=451 Comments and dictionary
MF = 2 Resonance parameters
MT=151 Resolved and unresolved resonance parameters
Resolved resonance region (MLBW; below 1 keV)
The data of JENDL-3.3 was adopted. JENDL-3.3 is the same as
JENDL-3.2.
** comments to JENDL-3.3 **
Resonance parameters were evaluated as follows: Resonance
energies, neutron and radiation widths were taken from the
measurement of Popov et al./2/ As for lowest two levels, the
parameters were taken from the compilation of Mughabghab et
al./3/ Total spin J for resonances measured by Popov et al.
was tentatively estimated with a random number method.
Neutron orbital angular momentum l was estimated with a method
of Bollinger and Thomas/4/. Average radiation width of 199
meV was deduced and adopted to the levels whose radiation
width was unknown. Scattering radius of 6.1 fm was assumed
from the systematics of measured values for neighboring
nuclides.
For JENDL-3.2, total spin J was determined based on the
measurements of Coceva et al./5/ and with a randum number
method.
Unresolved resonance region : 1 keV - 200 keV
The neutron strength functions, S0, S1 and S2 were calculated
with optical model code CASTHY/6/. The observed level
spacing was determined to reproduce the capture cross section
calculated with CASTHY. The effective scattering radius was
obtained from fitting to the calculated total cross section at
100 keV. The radiation width GG was based on the compilation
of Mughabghab et al./3/
Typical values of the parameters at 70 keV:
S0 = 0.440E-4, S1 = 4.200E-4, S2 = 0.600E-4, SG = 79.2E-4,
GG = 0.195 eV, R = 6.224 fm.
The unresolved resonance parameters were calculated using
the ASREP code/7/.
The parameters should be used only for self-shielding
calculation.
Thermal cross sections and resonance integrals at 300K (b)
-------------------------------------------------------
0.0253 eV reson. integ.(*)
-------------------------------------------------------
total 11.016
elastic 3.705
capture 7.312 171
-------------------------------------------------------
(*) In the energy range from 0.5 eV to 10 MeV.
MF = 3 Neutron cross sections
Below 1 keV, resolved resonance parameters were given.
The spherical optical and statistical model
calculation was performed with CASTHY, by taking account of
competing reactions, of which cross sections were calculated
with PEGASUS/8/ standing on a preequilibrium and multi-step
evaporation model. The OMP's for neutron given in Table 1 were
determined to reproduce a systematic trend of the total cross
section by changing Rso of Iijima-Kawai potential/9/. The
OMP's for charged particles are as follows:
Proton = Perey/10/
Alpha = Huizenga and Igo/11/
Deuteron = Lohr and Haeberli/12/
Helium-3 and triton = Becchetti and Greenlees/13/
Parameters for the composite level density formula of Gilbert
and Cameron/14/ were evaluated by Iijima et al./15/ More
extensive determination and modification were made in the
present work. Table 2 shows the level density parameters used
in the present calculation. Energy dependence of spin cut-off
parameter in the energy range below E-joint is due to Gruppelaar
/16/.
MT = 1 Total
Spherical optical model calculation was adopted.
MT = 2 Elastic scattering
Calculated as (total - sum of partial cross sections).
MT = 4, 51 - 91 Inelastic scattering
Spherical optical and statistical model calculation was
adopted. The level scheme was taken from Ref./17/.
No. Energy(MeV) Spin-parity
GR. 0.0 5/2 +
1 0.0894 3/2 +
2 0.3221 5/2 +
3 0.3404 7/2 +
4 0.4420 3/2 +
5 0.5755 5/2 +
6 0.6180 7/2 +
7 0.7192 9/2 +
8 1.0480 11/2 +
9 1.0700 11/2 -
10 1.3130 11/2 +
11 1.4960 13/2 +
12 1.5720 15/2 -
Levels above 1.7 MeV were assumed to be overlapping.
MT = 102 Capture
Spherical optical and statistical model calculation with
CASTHY was adopted. Direct and semi-direct capture cross
sections were estimated according to the procedure of Benzi
and Reffo/18/ and normalized to 1 milli-barn at 14 MeV.
The gamma-ray strength function (7.80E-03) was determined from
the radiation width (0.195+-0.020 eV) and average s-wave
resonance level spacing (25+-2 eV/3/).
MT = 16 (n,2n) Cross Section
MT = 17 (n,3n) Cross Section
MT = 22 (n,n'a) Cross Section
MT = 28 (n,n'p) Cross Section
MT = 32 (n,n'd) Cross Section
MT =103 (n,p) Cross Section
MT =104 (n,d) Cross Section
MT =105 (n,t) Cross Section
MT =106 (n,He3) Cross Section
MT =107 (n,alpha) Cross Section
These reaction cross sections were calculated with the
preequilibrium and multi-step evaporation model code PEGASUS.
The Kalbach's constant K (= 126.7) was estimated by the
formula derived from Kikuchi-Kawai's formalism/19/ and level
density parameters.
Finally, the (n,p) and (n,alpha) cross sections were
normalized to the following values at 14.5 MeV:
(n,p) 49.40 mb (systematics of Forrest/20/)
(n,alpha) 12.30 mb (systematics of Forrest)
MT = 251 Mu-bar
Calculated with CASTHY.
MF = 4 Angular Distributions of Secondary Neutrons
Legendre polynomial coefficients for angular distributions are
given in the center-of-mass system for MT=2 and discrete inelas-
tic levels, and in the laboratory system for MT=91. They were
calculated with CASTHY/6/.
MF = 5 Energy Distributions of Secondary Neutrons
Energy distributions of secondary neutrons were calculated with
PEGASUS for inelastic scattering to overlapping levels and for
other neutron emitting reactions.
Table 1 Neutron Optical Potential Parameters
Depth (MeV) Radius(fm) Diffuseness(fm)
---------------------- ------------ ---------------
V = 47.5 R0 = 5.972 a0 = 0.62
Ws = 9.74 Rs = 6.594 as = 0.35
Vso= 7.0 Rso= 5.97 aso= 0.62
The form of surface absorption part is der. Woods-Saxon type.
Table 2 Level Density Parameters
Nuclide a(1/MeV) T(MeV) C(1/MeV) EX(MeV) Pairing
---------------------------------------------------------------
42-Mo- 95 1.360E+01 7.150E-01 1.847E+00 5.835E+00 1.280E+00
42-Mo- 96 1.403E+01 7.410E-01 6.991E-01 7.645E+00 2.400E+00
42-Mo- 97 1.517E+01 6.800E-01 2.769E+00 6.036E+00 1.280E+00
42-Mo- 98 1.594E+01 6.900E-01 7.358E-01 7.888E+00 2.570E+00
43-Tc- 96 1.741E+01 5.640E-01 1.503E+01 3.650E+00 0.0
43-Tc- 97 1.600E+01 6.700E-01 4.756E+00 6.089E+00 1.120E+00
43-Tc- 98 1.659E+01 6.120E-01 1.776E+01 4.176E+00 0.0
43-Tc- 99 1.600E+01 6.550E-01 2.973E+00 5.984E+00 1.290E+00
44-Ru- 97 1.510E+01 6.390E-01 1.567E+00 5.300E+00 1.280E+00
44-Ru- 98 1.382E+01 7.400E-01 6.070E-01 7.507E+00 2.400E+00
44-Ru- 99 1.650E+01 6.570E-01 4.016E+00 6.235E+00 1.280E+00
44-Ru-100 1.520E+01 7.200E-01 7.835E-01 8.078E+00 2.570E+00
---------------------------------------------------------------
Spin cutoff parameters were calculated as 0.146*SQRT(a)*A**(2/3).
In the CASTHY calculation, spin cutoff factors at 0 MeV were
assumed to be 12.66 for Ru- 99 and 4.062 for Ru-100.
References
1) Kawai, M. et al.: J. Nucl. Sci. Technol., 29, 195 (1992).
2) Ju.P.Popov et al.: Yad. Fiz., 29, 561 (1979).
3) S.F.Mughabghab et al.: "Neutron Cross Sections, Vol. I,
Part A", Academic Press (1981).
4) L.M.Bollinger, G.E.Thomas: Phys. Rev., 171,1293(1968).
5) C.Coceva et al.: Nucl. Phys., A 117, 586 (1968).
6) Igarasi, S. and Fukahori, T.: JAERI 1321 (1991).
7) Y.Kikuchi et al., JAERI-Data/Code 99-025 (1999)
[in Japanese].
8) Iijima, S. et al.: JAERI-M 87-025, p. 337 (1987).
9) Iijima, S. and Kawai, M.: J. Nucl. Sci. Technol., 20, 77
(1983).
10) Perey, F.G: Phys. Rev. 131, 745 (1963).
11) Huizenga, J.R. and Igo, G.: Nucl. Phys. 29, 462 (1962).
12) Lohr, J.M. and Haeberli, W.: Nucl. Phys. A232, 381 (1974).
13) Becchetti, F.D., Jr. and Greenlees, G.W.: Polarization
Phenomena in Nuclear Reactions ((eds) H.H. Barshall and
W. Haeberli), p. 682, The university of Wisconsin Press.
(1971).
14) Gilbert, A. and Cameron, A.G.W.: Can. J. Phys., 43, 1446
(1965).
15) Iijima, S., et al.: J. Nucl. Sci. Technol. 21, 10 (1984).
16) Gruppelaar, H.: ECN-13 (1977).
17) Lederer, C.M., et al.: "Table of Isotopes, 7th Ed.", Wiley-
Interscience Publication (1978).
18) Benzi, V. and Reffo, G.: CCDN-NW/10 (1969).
19) Kikuchi, K. and Kawai, M.: "Nuclear Matter and Nuclear
Reactions", North Holland (1968).
20) Forrest, R.A.: AERE-R 12419 (1986).