91-Pa-232 JAEA+ EVAL-FEB10 O.Iwamoto, T.Nakagawa, et al.
DIST-MAY10 20100323
----JENDL-4.0 MATERIAL 9134
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
History
03-02 Resolved resonance parameters and cross sections below 30
keV were updated.
07-08 Resolved resonance parameters were modified.
07-10 Theoretical calculation was carried out with CCONE code.
Data were compiled as JENDL/AC-2008/1/.
09-04 Numbers of prompt and delayed neutrons were revised.
10-02 Data of prompt gamma rays due to fission were given.
10-03 Covariance data were given.
MF=1 General information
MT=452 Number of Neutrons per fission
Sum of MT's=455 and 456.
MT=455 Delayed neutron data
Determined from nu-d of the following three fissioning
nuclides and partial fission cross sections calculated with
CCONE code/2/.
Pa-233 = 0.01577
Pa-232 = 0.01083
Pa-231 = 0.007461
They are averages of systematics by Tuttle/3/,
Benedetti et al./4/ and Waldo et al./5/
MT=456 Number of prompt neutrons per fission
Estimated from Ohsawa's systematics/6/.
nup = 2.0860 + 0.13668*E(MeV)
MF=2 Resonance parameters
MT=151 Resonance parameters
Resolved resonance parameters (1.0E-5 to 21 eV, MLBW)
Parameters evaluated by Bakhanovich et al./7/ were adopted
after modifying parameters of a negative resonance and adding
one at -0.3 eV so as to reproduce thermal cross sections.
The data of Danon et al./8/ were used for the evaluation by
Bakhanovich et al.
Thermal cross sections to be reproduced:
capture = 589+-56 /9,10/
fission = 1488+-14 /8,11/
Unresolved resonance parameters (21 eV - 10 keV)
Cross sections were reproduced with average resonance
parameters determined by ASREP code/12/. These parameters
are used only for self-shielding effects.
Thermal cross sections and resonance integrals (at 300K)
-------------------------------------------------------
0.0253 eV reson. integ.(*)
(barns) (barns)
-------------------------------------------------------
total 2100.3
elastic 23.91
fission 1487.4 931
capture 589.0 165
-------------------------------------------------------
(*) In the energy range from 0.5 eV to 10 MeV.
MF=3 Neutron cross sections
Cross sections above the resolved resonance region were
calculated with CCONE code/2/.
MT= 1 Total cross section
The cross section was calculated with CC OMP of Soukhovitskii
et al./13/.
MT=18 Fission cross section
The experimental data of Danon et al./8/ and the simulated
(n,f) cross sections of Britt and Wilhelmy/14/ were used to
determine the parameters in the CCONE calculation.
MF= 4 Angular distributions of secondary neutrons
MT=2 Elastic scattering
Calculated with CCONE code/2/.
MT=18 Fission
Isotropic distributions in the laboratory system were assumed.
MF= 5 Energy distributions of secondary neutrons
MT=18 Prompt neutrons
Calculated with CCONE code/2/.
MF= 6 Energy-angle distributions
Calculated with CCONE code/2/.
Distributions from fission (MT=18) are not included.
MF=12 Photon production multiplicities
MT=18 Fission
Calculated from the total energy released by the prompt
gamma-rays due to fission which was estimated from its
systematics, and the average energy of gamma-rays.
MF=14 Photon angular distributions
MT=18 Fission
Isotoropic distributions were assumed.
MF=15 Continuous photon energy spectra
MT=18 Fission
Experimental data measured by Verbinski et al./15/ for
U-235 thermal fission were adopted.
MF=31 Covariances of average number of neutrons per fission
MT=452 Number of neutrons per fission
Sum of covariances for MT=455 and MT=456.
MT=455
Error of 15% was assumed.
MT=456
Covariance was obtained by fitting a linear function to the
data at 0.0 and 5.0 MeV with an uncertainty of 5%.
MF=32 Covariances of resonance parameters
MT=151 Resolved resonance parameterss
Format of LCOMP=0 was adopted.
Uncertainties of parameters were assumed as follows:
Resonance energy 0.1 %
Neutron width 10 %
Capture width 50 %
Fission width 20 %
They were further modified by considering experimental data
of the fission and capture cross sections at the thermal
neutron energy.
MF=33 Covariances of neutron cross sections
Covariances were given to all the cross sections by using
KALMAN code/16/ and the covariances of model parameters
used in the cross-section calculations.
Covariances of the total, elastic-scattering, fission and
capture cross sections were determined by considering the
experimental data (see MF=3).
In the resolved resonance region, the following standard
deviations were added to the contributions from resonance
parameters:
Total 2 b
Elastic scattering 20 %
MF=34 Covariances for Angular Distributions
MT=2 Elastic scattering
Covariances were given only to P1 components.
MF=35 Covariances for Energy Distributions
MT=18 Fission spectra
Estimated with CCONE and KALMAN codes.
*****************************************************************
Calculation with CCONE code
*****************************************************************
Models and parameters used in the CCONE/2/ calculation
1) Coupled channel optical model
Levels in the rotational band were included. Optical model
potential and coupled levels are shown in Table 1.
2) Two-component exciton model/17/
* Global parametrization of Koning-Duijvestijn/18/
was used.
* Gamma emission channel/19/ was added to simulate direct
and semi-direct capture reaction.
3) Hauser-Feshbach statistical model
* Moldauer width fluctuation correction/20/ was included.
* Neutron, gamma and fission decay channel were included.
* Transmission coefficients of neutrons were taken from
coupled channel calculation in Table 1.
* The level scheme of the target is shown in Table 2.
* Level density formula of constant temperature and Fermi-gas
model were used with shell energy correction and collective
enhancement factor. Parameters are shown in Table 3.
* Fission channel:
Double humped fission barriers were assumed.
Fission barrier penetrabilities were calculated with
Hill-Wheler formula/21/. Fission barrier parameters were
shown in Table 4. Transition state model was used and
continuum levels are assumed above the saddles. The level
density parameters for inner and outer saddles are shown in
Tables 5 and 6, respectively.
* Gamma-ray strength function of Kopecky et al/22/,/23/
was used. The prameters are shown in Table 7.
------------------------------------------------------------------
Tables
------------------------------------------------------------------
Table 1. Coupled channel calculation
--------------------------------------------------
* rigid rotor model was applied
* coupled levels = 0,1,2,3 (see Table 2)
* optical potential parameters /13/
Volume:
V_0 = 49.97 MeV
lambda_HF = 0.01004 1/MeV
C_viso = 15.9 MeV
A_v = 12.04 MeV
B_v = 81.36 MeV
E_a = 385 MeV
r_v = 1.2568 fm
a_v = 0.633 fm
Surface:
W_0 = 17.2 MeV
B_s = 11.19 MeV
C_s = 0.01361 1/MeV
C_wiso = 23.5 MeV
r_s = 1.1803 fm
a_s = 0.601 fm
Spin-orbit:
V_so = 5.75 MeV
lambda_so = 0.005 1/MeV
W_so = -3.1 MeV
B_so = 160 MeV
r_so = 1.1214 fm
a_so = 0.59 fm
Coulomb:
C_coul = 1.3
r_c = 1.2452 fm
a_c = 0.545 fm
Deformation:
beta_2 = 0.213
beta_4 = 0.066
beta_6 = 0.0015
* Calculated strength function
S0= 0.90e-4 S1= 1.92e-4 R'= 9.70 fm (En=1 keV)
--------------------------------------------------
Table 2. Level Scheme of Pa-232
-------------------
No. Ex(MeV) J PI
-------------------
0 0.00000 2 - *
1 0.06000 3 - *
-------------------
*) Coupled levels in CC calculation
Table 3. Level density parameters
--------------------------------------------------------
Nuclide a* Pair Eshell T E0 Ematch
1/MeV MeV MeV MeV MeV MeV
--------------------------------------------------------
Pa-233 16.7739 0.7861 3.1759 0.4375 -1.3104 3.5616
Pa-232 17.9699 0.0000 2.9784 0.2779 -0.6740 1.0000
Pa-231 17.9034 0.7895 3.1164 0.4176 -1.2470 3.5007
Pa-230 17.8368 0.0000 2.9470 0.2794 -0.6728 1.0000
Pa-229 17.7702 0.7930 3.0707 0.3881 -0.8689 3.0597
--------------------------------------------------------
Table 4. Fission barrier parameters
----------------------------------------
Nuclide V_A hw_A V_B hw_B
MeV MeV MeV MeV
----------------------------------------
Pa-233 5.800 0.800 6.000 0.520
Pa-232 5.800 0.800 6.180 0.400
Pa-231 6.000 0.800 5.750 0.520
Pa-230 5.800 0.800 6.180 0.400
Pa-229 6.000 0.800 5.800 0.520
----------------------------------------
Table 5. Level density above inner saddle
--------------------------------------------------------
Nuclide a* Pair Eshell T E0 Ematch
1/MeV MeV MeV MeV MeV MeV
--------------------------------------------------------
Pa-233 21.6437 0.9172 2.6000 0.3187 -1.4511 2.9172
Pa-232 20.6654 0.0000 2.6000 0.3415 -2.6081 2.2000
Pa-231 20.5889 0.9211 2.6000 0.3276 -1.4734 2.9211
Pa-230 20.5123 0.0000 2.6000 0.3428 -2.6080 2.2000
Pa-229 20.4357 0.9251 2.6000 0.3435 -1.6829 3.1251
--------------------------------------------------------
Table 6. Level density above outer saddle
--------------------------------------------------------
Nuclide a* Pair Eshell T E0 Ematch
1/MeV MeV MeV MeV MeV MeV
--------------------------------------------------------
Pa-233 21.6437 0.9172 -0.0400 0.3439 -0.6013 2.7172
Pa-232 20.6654 0.0000 -0.0800 0.4050 -2.1087 2.5000
Pa-231 20.5889 0.9211 -0.1200 0.3706 -0.7702 2.9211
Pa-230 20.5123 0.0000 -0.1600 0.3867 -1.8562 2.2000
Pa-229 20.4357 0.9251 -0.2000 0.3880 -0.9302 3.1251
--------------------------------------------------------
Table 7. Gamma-ray strength function for Pa-233
--------------------------------------------------------
K0 = 0.800 E0 = 4.500 (MeV)
* E1: ER = 11.03 (MeV) EG = 2.71 (MeV) SIG = 302.00 (mb)
ER = 13.87 (MeV) EG = 4.77 (MeV) SIG = 449.00 (mb)
* M1: ER = 6.66 (MeV) EG = 4.00 (MeV) SIG = 1.82 (mb)
* E2: ER = 10.24 (MeV) EG = 3.31 (MeV) SIG = 6.38 (mb)
--------------------------------------------------------
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