91-Pa-233
91-Pa-233 JAEA+ EVAL-FEB10 O.Iwamoto, T.Nakagawa, et al.
DIST-MAY10 20100318
----JENDL-4.0 MATERIAL 9137
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
History
06-07 Resonance parameters were modified.
07-10 Theoretical calculation was done with CCONE code.
Data were compiled as JENDL/AC-2008/1/.
08-12 (1,455) was modified.
09-04 (1,452), (1,455) and (1,456) 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-234 = 0.02301
Pa-233 = 0.01577
Pa-232 = 0.01083
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/.
MF= 2 Resonance parameters
MT=151
Resolved resonance parameters (MLBW: 1.0E-5 - 100 eV)
Resonance parameters evaluated by Morogovskii and Bakhanovich
/7/ were adopted. Total spin of each resonance was
assigned at random. Parameters of a negative resonance were
adjusted to the thermal cross sections.
The thermal cross sections to be reproduced:
Total = 55.0 +- 4.2 b
Simpson et al./8/
Capture = 39.4 +- 1.2 b
Smith et al./9/, Eastwood et al./10/, Halperin et
al./11/, Connor/12/, Bringer et al./13/
Unresolved resonance parameters (100 eV - 10 keV)
Cross sections were reproduced with average resonance
parameters determined by ASREP code/14/. 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 53.56
elastic 14.14
fission 2.5E-6 0.977
capture 39.42 835
-------------------------------------------------------
(*) 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./15/ with modification of the quadrupole deformation
parameter.
MT=18, 19 Fission cross section
Above 30 keV, calculated with CCONE code.
From 1 eV to 10 keV, a constant cross section of 4.0E-7 b
was assumed.
Below 1 eV, 1/v shape cross section was assumed.
The experimental data of Petit et al./16/ and Tovesson et
al./17/ 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./18/ 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 taken from Mughabghab /19/.
For the parameters without any information on uncertainty,
the following uncertainties were assumed:
Resonance energy 0.1 %
Neutron width 10 %
Capture width 50 %
Fission width 20 %
They were further modified by considering experimental data
of the capture cross section at the thermal neutron energy.
MF=33 Covariances of neutron cross sections
Covariances were given to all the cross sections by using
KALMAN code/20/ and the covariances of model parameters
used in the cross-section calculations.
Covariances of the fission cross section 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 0 - 10 %
Elastic scattering 20 %
Fission 90 %
Capture 0 - 10 %
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/21/
* Global parametrization of Koning-Duijvestijn/22/
was used.
* Gamma emission channel/23/ was added to simulate direct
and semi-direct capture reaction.
3) Hauser-Feshbach statistical model
* Moldauer width fluctuation correction/24/ 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/25/. 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/26/,/27/
was used. The prameters are shown in Table 7.
------------------------------------------------------------------
Tables
------------------------------------------------------------------
Table 1. Coupled channel calculation
--------------------------------------------------
* rigid rotor model was applied
* coupled levels = 0,1,2,3,9,12 (see Table 2)
* optical potential parameters /15/
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 = 0.19
beta_4 = 0.066
beta_6 = 0.0015
* Calculated strength function
S0= 0.73e-4 S1= 2.68e-4 R'= 9.58 fm (En=1 keV)
--------------------------------------------------
Table 2. Level Scheme of Pa-233
-------------------
No. Ex(MeV) J PI
-------------------
0 0.00000 3/2 - *
1 0.00667 1/2 - *
2 0.05710 7/2 - *
3 0.07054 5/2 - *
4 0.08647 5/2 +
5 0.09465 3/2 +
6 0.10364 7/2 +
7 0.10907 9/2 +
8 0.13320 11/2 +
9 0.16351 11/2 - *
10 0.16917 1/2 +
11 0.17300 13/2 +
12 0.17900 9/2 - *
13 0.20163 3/2 +
14 0.21234 5/2 +
15 0.23789 5/2 +
16 0.25718 5/2 -
17 0.27972 7/2 +
18 0.29600 5/2 +
19 0.30050 7/2 +
20 0.30359 9/2 +
21 0.30610 7/2 -
22 0.32380 15/2 -
23 0.33080 13/2 -
24 0.35500 3/2 +
25 0.35500 9/2 -
-------------------
*) 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-234 18.1029 0.0000 3.1132 0.2754 -0.6749 1.0000
Pa-233 18.0364 0.7861 3.1759 0.4099 -1.1882 3.4195
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
--------------------------------------------------------
Table 4. Fission barrier parameters
----------------------------------------
Nuclide V_A hw_A V_B hw_B
MeV MeV MeV MeV
----------------------------------------
Pa-234 5.800 0.800 6.300 0.400
Pa-233 5.900 0.800 6.100 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
----------------------------------------
Table 5. Level density above inner saddle
--------------------------------------------------------
Nuclide a* Pair Eshell T E0 Ematch
1/MeV MeV MeV MeV MeV MeV
--------------------------------------------------------
Pa-234 20.8184 0.0000 2.6000 0.3401 -2.6082 2.2000
Pa-233 19.8401 0.9172 2.6000 0.3346 -1.5060 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
--------------------------------------------------------
Table 6. Level density above outer saddle
--------------------------------------------------------
Nuclide a* Pair Eshell T E0 Ematch
1/MeV MeV MeV MeV MeV MeV
--------------------------------------------------------
Pa-234 20.2753 0.0000 -0.0000 0.3874 -1.8655 2.2000
Pa-233 19.8401 0.9172 -0.0400 0.3622 -0.6209 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
--------------------------------------------------------
Table 7. Gamma-ray strength function for Pa-234
--------------------------------------------------------
K0 = 1.501 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 = 6.65 (MeV) EG = 4.00 (MeV) SIG = 2.77 (mb)
* E2: ER = 10.22 (MeV) EG = 3.30 (MeV) SIG = 6.38 (mb)
--------------------------------------------------------
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