1-H - 3 LANL EVAL-NOV01 G.M.Hale
DIST-DEC21 20211105
----JENDL-5 MATERIAL 131
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
History
21-11 JENDL-5b3 revised by N.Iwamoto
Data taken from ENDF/B-VIII.0.
21-11 revised by O.Iwamoto
(MF8/MT16) added
*** (n,2n) replaced by ENDF/B-VI.8, total adjusted (NNDC/2010/06 *
n-t scattering evaluation, based on an R-matrix analysis of p-3He
scattering that was transformed from the 4Li system to the 4H
system by moving all the eigenenergies downward by a Coulomb
energy shift of 0.86 MeV. The calculated neutron total cross
section then agreed well with new measurements [1] by Phillips et
al, and the coherent scattering length with a new measurement [2]
from Rauch, as was described in ref. [3]. The parameters of the
fit have been used to calculate total cross sections and elastic
cross sections and angular distributions in the energy range from
10^(-5) eV to 20 MeV. Some allowance was made for the (n,2n)
breakup cross section at energies above 8.4 MeV, so that the total
cross section exceeds the elastic cross section in that energy
region.
*****************************************************************
MF=1
MT=451 Nuclear mass = 3.01550116
MF=2
MT=151 Scattering length=0.36399 X 10^(-12) cm
MF=3
MT=1 Total cross sections: calculated from
R-matrix parameters after adjusting the
Coulomb energy shift to agree with the
measurements of ref [1], which disagree
significantly with earlier data [4] at
low energies.
MT=2. Elastic scattering cross sections:
calculated from the n-t R-matrix
parameters described above. Identical
with MT=1 at energies below 8.4 MeV.
MT=16 (n,2n) cross sections: non-zero cross
section obtained from allowing two-body
nn-d and nn-d0 absorption channels to
couple to the n-t states. This method
probably underestimates the amount of
(n,2n) cross section at energies above
8.4 MeV.
NOT GIVEN IN MF=3:
MT=17 (n,3n) cross section: no data given
since estimates from isospin con-
siderations give essentially zero
probabilities.
MT=102 radiative capture cross section: The
measured cross section is less than or
equal to 6.7 microbarns at thermal.
Since the Q-value is uncertain, but
either zero or negative, this cross
section assumed zero at all energies.
MF=4
MT=2 Neutron elastic angular distributions
in the center-of-mass system: given as
Legendre coefficients calculated from
the n-t R-matrix parameters.
NOT GIVEN: MF=12, 13, 14, AND 15
***************************************************************
Only radiative capture produces gamma
rays. Since the capture cross section
is assumed zero at all energies, these
files are purposely left empty.
REFERENCES
[1] T.W. Phillips, B.L. Berman and J.D. Seagrave, Phys. Rev. C 22,
384 (1980).
[2] H. Rauch, D. Tuppinger, H. Wolwitsch and T. Wroblewski, Phys.
Lett. 165B, 39 (1985).
[3] G.M. Hale, D.C. Dodder, J.D. Seagrave, B.L. Berman and T.W.
Phillips, Phys. Rev. C 42, 438 (1990).
[4] Los Alamos Physics and Cryogenics Group, Nucl. Phys. 12, 291
(1959).