33-As- 75
33-AS- 75 JNDC EVAL-MAR90 JNDC FP NUCLEAR DATA W.G.
DIST-MAR02 REV3-JUL01 20010713
----JENDL-3.3 MATERIAL 3325
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
HISTORY
90-03 New evaluation for JENDL-3 was completed by JNDC FPND
W.G./1/
94-02 JENDL-3.2
JENDL-3.1 was replaced with JENDL fusion file
Compiled by T.Nakagawa
***** Modified parts for JENDL-3.2 ********************
All cross sections except (3,102).
(3,32), (3,33), (3,105) and (3,106) were deleted.
All angular distributions except for (4,2).
All energy distributions.
***********************************************************
-------------------------------------------------------------
JENDL fusion file /2/ (as of Feb. 1994)
Evaluated by K.Kosako (nedac) and S. Chiba (ndc/JAERI)
Compiled by K.Kosako.
- The inelastic scattering cross sections and angular
distributions of inelastically scattered neutrons (except
continuum inelastic) were calculated with casthy2y and
dwucky in sincros-ii system/3/.
- The (n,2n), (n,3n), (n,na), (n,np), (n,p), (n,d) and
(n,a) reaction cross sections (mt=16, 17, 22, 28, 103,
104, 107) were calculated by egnash2 in the sincros-II.
- The capture cross section, resonance parameters and ang.
distributions of elastically scattered neutrons were
taken from JENDL-3.1.
- Energy distributions of secondary neutrons were calcu-
lated by egnash2. The ddx's of the continuum neutrons
were obtained from Kumabe's systematics /4/ using
f15tob/2/. The precompound to compound ratio was
calculated by the sincros- II code system.
- Optical-model, level density and other parameters used in
the sincros-II calculation are described in ref./3/.
Level schemes were determined on the basis of ENSDF/5/.
-------------------------------------------------------------
00-10 JENDL-3.3
Compile by K.Shibata (jaeri).
***** Modified parts for JENDL-3.3 ************************
(1,451) Updated.
(3,203-207) Calculated.
(3,251) Deleted.
(4,2) Transformation matrix deleted.
(4,16-91) Deleted.
(5,16-91) Deleted.
(6,16-91) Taken from JENDL fusion file
************************************************************
mf = 1 General information
mt=451 Comments and dictionary
mf = 2 Resonance parameters (same as JENDL-3.1)
mt=151 Resolved and unresolved resonance parameters
Resolved resonance region (MLBW formula) : Below 9.7 keV
resonance parameters for the 39 levels from 47.0 to 2616 eV
were evaluated on the basis of the data given by Mughabghab et
al./6/ Resonance energies for the 210 levels from 2676 to
11960 eV were based on the measurement by Macklin/7/. Neutron
and radiation widths for the 210 levels were determined by
different methods according to the following three conditions,
respectively.
1) In cases where total width and neutron capture area
measured by macklin are given for a resonance level, the
neutron and radiation widths were simultaneously obtained by
solving a quadratic equation.
2) In cases where neutron capture area measured by Macklin and
2g*(neutron width) given by Mughabghab et al. are available
for a resonance level, the radiation widths were derived from
the both data.
3) In cases where only neutron capture area by Macklin is
available, or g*(neutron width) by Mughabghab et al. is
smaller than neutron capture area by Macklin for a resonance
level, the average radiation width of 318 meV given by macklin
was adopted for the level. The neutron width was derived from
this average radiation width and the neutron capture area.
Neutron orbital angular momentum l of some resonances was
estimated with a method of Bollinger and Thomas/8/. Total
spin j of some resonances was tentatively estimated with a
random number method. Scattering radius was taken from
Mughabghab et al. Two negative resonances were added so as to
reproduce the thermal capture and scattering cross sections
given by Mughabghab et al.
Unresolved resonance region : 9.7 keV - 100 keV
The neutron strength function s0 was based on the compilation
of Mughabghab et al., and S1 was based on the systematics of
Mughabghab et al., and S2 was calculated with optical model
code casthy/9/. The radiation width Gg was based on the
compilation of Mughabghab et al. 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.
Typical values of the parameters at 70 keV:
S0 = 1.700e-4, S1 = 1.100e-4, S2 = 0.773e-4, Sg = 43.3e-4,
Gg = 0.300 ev, R = 7.248 fm.
calculated 2200-m/s cross sections and res. integrals (barns)
2200 m/s res. integ.
total 9.930 -
elastic 5.430 -
capture 4.500 63.9
mf = 3 Neutron cross sections
Below 100 keV, resonance parameters were given.
For JENDL-3.1, above 100 keV, 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/10/ 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 r0, rs and rso of
Iijima-Kawai potential/11/. The omp's for charged particles are
as follows:
proton = Perey/12/
alpha = Huizenga and Igo/13/
deuteron = Lohr and Haeberli/14/
helium-3 and triton = Becchetti and Greenlees/15/
Parameters for the composite level density formula of Gilbert
and Cameron/16/ were evaluated by Iijima et al./17/ 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
/18/.
For JENDL-3.2, all cross section data except for the elastic
scattering and capture were adopted from JENDL fusion file. The
calculation was made with sincros-II system/3/ by adopting
Walter-Guss omp modified by Yamamuro/3/ for neutron, Perey omp
/19/ for proton, Lemos omp modified by Arthur and Young/20/ for
alpha, Lohr-Haeberli omp/21/ for deuteron, Becchettii-Greenlees
omp/15/ for triton and he-3, and standard level density
parameters of sincros-II system.
mt = 1 Total
Taken from JENDL fusio file. Spherical optical model calcula-
on with casthy and modified Walter-Guss potential was adopted.
mt = 2 Elastic scattering
Calculated as (total - sum of partial cross sections).
mt = 4, 51 - 91 Inelastic scattering
Taken from JENDL fusion file. The level scheme was based on
ref./5/ contributions of the direct process were calculated
for the levels marked with '*'.
no. energy(MeV) spin-parity (direct process)
gr. 0.0 3/2 -
1 0.1986 1/2 - *
2 0.2647 3/2 - *
3 0.2795 5/2 - *
4 0.3039 9/2 + *
5 0.4007 5/2 + *
6 0.4686 1/2 - *
7 0.5722 5/2 - *
8 0.5850 1/2 -
9 0.6177 1/2 - *
10 0.8216 7/2 - *
Levels above 0.823 MeV were assumed to be overlapping.
mt = 102 Capture (same as JENDL-3.1)
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/22/ and normalized to 1 milli-barn at 14 mev.
The gamma-ray strength function (3.84e-03) was adjusted to
reproduce the capture cross section of 350 milli-barns at 50
keV measured by Macklin/7/.
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 =103 (n,p) cross section
mt =104 (n,d) cross section
mt =107 (n,alpha) cross section
Adopted from JENDL fusion file. Theoretical calculation was
made with sincros-II. The results were normalized to
(n,2n) 0.804-0.991 b in 13.34-14.93 MeV by Konno+/23/,
(n,d)+(n,np) 0.0111 b at 14.5 MeV (systematics of Forrest/24/),
(n,p) 0.0198-0.0172b in 13.33-14.92 MeV by Konno+/23/,
(n,a) 0.01007 b at 13.98 MeV by Konno+/23/.
mt = 203 Total proton production
Sum of mt=28 and 103.
mt = 204 Total deuteron production
Equal to mt=104.
mt = 207 Total alpha production
Sum of mt=22 and 107.
mf = 4 Angular distributions of secondary neutrons
mt=2 (same as JENDL-3.1)
Calculated with the casthy code/9/.
mt=51-60
Taken from JENDL fusion file.
mf = 6 Energy-angle distributions of secondary particles
mt=16, 17, 22, 28, 91, 203, 204, 207
Taken from JENDL fusion file.
<< The parameters used in the casthy and pegasus calculations. >>
Table 1 Neutron optical potential parameters
depth (MeV) radius(fm) diffuseness(fm)
---------------------- ------------ ---------------
V = 46.0-0.25E r0 = 5.7 a0 = 0.62
Ws = 7.0 rs = 6.2 as = 0.35
Vso= 7.0 rso= 5.7 aso= 0.62
The form of surface absorption part is der. Woods-Saxon type.
Table 2 Level density parameters
nuclide syst a(1/MeV) t(MeV) c(1/MeV) Ex(MeV) pairing
---------------------------------------------------------------
31-Ga- 71 * 1.332e+01 9.155e-01 1.399e+01 9.613e+00 1.430e+00
31-Ga- 72 * 1.390e+01 9.028e-01 9.003e+01 8.399e+00 0.0
31-Ga- 73 1.269e+01 8.264e-01 1.933e+00 7.808e+00 1.880e+00
31-Ga- 74 * 1.350e+01 8.784e-01 5.236e+01 7.551e+00 0.0
32-Ge- 72 * 1.350e+01 9.028e-01 3.062e+00 1.086e+01 2.790e+00
32-Ge- 73 * 1.409e+01 8.904e-01 1.973e+01 9.644e+00 1.360e+00
32-Ge- 74 * 1.384e+01 8.784e-01 1.667e+00 1.106e+01 3.240e+00
32-Ge- 75 * 1.368e+01 8.667e-01 1.100e+01 8.810e+00 1.360e+00
33-As- 73 * 1.369e+01 8.904e-01 1.364e+01 9.389e+00 1.430e+00
33-As- 74 1.132e+01 9.475e-01 1.967e+01 7.033e+00 0.0
33-As- 75 1.250e+01 9.510e-01 6.830e+00 1.008e+01 1.880e+00
33-As- 76 1.330e+01 7.860e-01 1.900e+01 5.611e+00 0.0
---------------------------------------------------------------
syst: * = ldp's were determined from systematics.
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 3.5 for As- 75 and 5.0 for As- 76.
References
1) Kawai, M. et al.: To be publisehd.
2) Chiba, S. et al.: JAERI-M 92-027, p.35 (1992).
3) Yamamuro, N.: JAERI-M 90-006 (1990).
4) Kumabe, I. et al.: Nucl. Sci. Eng., 104, 280 (1990).
5) ENSDF: Evaluated Nuclear Structure Data File, BNL/NNDC.
6) Kawai, M. et al.: J. Nucl. Sci. Technol., 29, 195 (1992).
7) Macklin, R.L.: Nucl. Sci. Eng. 99, 133 (1988).
8) Bollinger, L.M. and Thomas, G.E.: Phys. Rev., 171,1293(1968).
9) Igarasi, S. and Fukahori, T.: JAERI 1321 (1991).
10) Iijima, S. et al.: JAERI-M 87-025, p. 337 (1987).
11) Iijima, S. and Kawai, M.: J. Nucl. Sci. Technol., 20, 77
(1983).
12) Perey, F.G: Phys. Rev. 131, 745 (1963).
13) Huizenga, J.R. and Igo, G.: Nucl. Phys. 29, 462 (1962).
14) Lohr, J.M. and Haeberli, W.: Nucl. Phys. A232, 381 (1974).
15) 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).
16) Gilbert, A. and Cameron, A.G.W.: Can. J. Phys., 43, 1446
(1965).
17) Iijima, S., et al.: J. Nucl. Sci. Technol. 21, 10 (1984).
18) Gruppelaar, H.: ECN-13 (1977).
19) Perey, F.G.: Phys. Rev., 131, 745 (1963).
20) Arthur, E.D. and Young, P.G.: LA-8626-MS (1980).
21) Lohr, J.M. and Haeberli W.: Nucl. Phys., A232, 381 (1974).
22) Benzi, V. and Reffo, G.: CCDN-NW/10 (1969).
23) Konno, C. et al.: JAERI 1329 (1993).
24) Forrest, R.A.: AERE-R 12419 (1986).