Low-Fidelity Covariances

Neutron Cross Section Covariance Estimates for 387 Materials

Warning: Not approved by CSEWG, not part of ENDF/B-VII.0

Click on the element, then on the isotope (material) to get plots of uncertainties and correlation matrices.

Numerical values can be retrieved using the link above the plots.

1
H		 2
He
3
Li		 4
Be		 5
B		 6
C		 7
N		 8
O		 9
F		 10
Ne
11
Na		 12
Mg		 13
Al		 14
Si		 15
P		 16
S		 17
Cl		 18
Ar
19
K		 20
Ca		 21
Sc		 22
Ti		 23
V		 24
Cr		 25
Mn		 26
Fe		 27
Co		 28
Ni		 29
Cu		 30
Zn		 31
Ga		 32
Ge		 33
As		 34
Se		 35
Br		 36
Kr
37
Rb		 38
Sr		 39
Y		 40
Zr		 41
Nb		 42
Mo		 43
Tc		 44
Ru		 45
Rh		 46
Pd		 47
Ag		 48
Cd		 49
In		 50
Sn		 51
Sb		 52
Te		 53
I		 54
Xe
55
Cs		 56
Ba		 57
La		 72
Hf		 73
Ta		 74
W		 75
Re		 76
Os		 77
Ir		 78
Pt		 79
Au		 80
Hg		 81
Tl		 82
Pb		 83
Bi		 84
Po		 85
At		 86
Rn
87
Fr		 88
Ra		 89
Ac		 104
Rf		 105
Db		 106
Sg		 107
Bh		 108
Hs		 109
Mt		 110
Ds		 111
Rg		 112
Cn		 113
Nh		 114
Fl		 115
Mc		 116
Lv		 117
Ts		 118
Og
 
58
Ce		 59
Pr		 60
Nd		 61
Pm		 62
Sm		 63
Eu		 64
Gd		 65
Tb		 66
Dy		 67
Ho		 68
Er		 69
Tm		 70
Yb		 71
Lu
90
Th		 91
Pa		 92
U		 93
Np		 94
Pu		 95
Am		 96
Cm		 97
Bk		 98
Cf		 99
Es		 100
Fm		 101
Md		 102
No		 103
Lr

Contents

Covariance data are provided for radiative capture (or (n,ch.p.) for light nuclei), elastic scattering (or total for some actinides), inelastic scattering, (n,2n) reactions, fission and nubars over the energy range from 10-5 eV to 20 MeV. The library contains 387 files including almost all (383 out of 393) materials of the ENDF/B-VII.0. Absent are data for 7Li, 232Th, 233,235,238U and 239Pu as well as 223,224,225,226Ra, while natZn is replaced by 64,66,67,68,70Zn.


Reference

R.C. Little et al., "Low-Fidelity Covariance Project", Nuclear Data Sheets 109 (2008) 2828-2833; for those without full access to NDS we offer draft version of the paper.


Retrieval and plotting

The Sigma retrieval and plotting package developed by the NNDC is used to retrieve and plot uncertainties and correlation matrices. No processing is performed - Sigma directly plots MF33 data (cross section covariances) and MF31 data (nubar covariances). In some cases processing using cross sections (MF3) is required to get covariances and plots which could not be produced.


Acknowledgement

Low-Fidelity Covariance Project, conducted by ANL-BNL-LANL-ORNL cpllaboration in FY2007-FY2008, was sponsored by the US Nuclear Criticality Safety program managed by DOE-NNSA.