Etude et impact du bruit de fond corrélé pour la mesure de l'angle ...

172 LIST OF FIGURES
4.16 Trigger e ciency as function of energy. The trigger e ciency
is of about 50 % at 0.4 MeV and 100.0 0.0
0.1 % at 0.7 MeV
(prompt lower cut). Above 0.8 MeV the trigger e ciency is
100.0 ± 0.0 %. . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
4.17 Trigger e ciency uncertainty breakdown. Uncertainty on the
trigger e ciency comes mainly from statistical fluctuation,
definition of trigger release time, energy conversion and from
the method itself. . . . . . . . . . . . . . . . . . . . . . . . . 95
tel-00821629, version 1 - 11 May 2013
4.18 252 Cf neutron energy spectrum for data and MC (left). Spectral
fit function, used to estimate the fraction on neutron captured
on Gd (right). Due to the 252 Cf neutron multiplicity
(3.869 ± 0.078 neutrons per fission [53]), peaks for the simultaneous
captures of two neutrons on Gd and H (⇠ 10 MeV)
and two captures on Gd (⇠ 16 MeV) are also seen. . . . . . . 96
4.19 t cut e ciency (left) and data/MC discrepancy (right) as a
function of the 252 Cf source position along the z-axis. . . . . . 97
4.20 t cut e ciency (left) and data/MC discrepancy (right) as a
function of the 252 Cf source radial position along guide tube. 97
4.21 t cut e ciency extrapolation from the detector center to
the edges. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
4.22 E cut e ciency (left) and data/MC discrepancy (right) as
a function of the 252 Cf source radial position along z-axis. . . 98
4.23 E cut e ciency (left) and data/MC discrepancy (right) as
a function of the 252 Cf source radial position along guide tube. 98
4.24 Covariance matrixes due to statistical fluctuation and systematic
uncertainties on the reactor simulations, the detector
response and background spectral shape. The matrixes are
drown from MC simulation. . . . . . . . . . . . . . . . . . . . 103
4.25 Measured prompt energy spectrum for each integration periods
(black points) superimposed on the expected prompt energy
spectrum, including backgrounds (green region), for the
non-oscillation hypothesis (blue dotted histogram) and best
fit (red solid histogram) at sin 2 (2✓ 13 )=0.109±0.030(stat.)±
0.025(syst.) at m 2 31 = 2.32 ⇥ 10 3 eV 2 , with 2 /ndf =
42.1/35 [20]. The insert shown the backgrounds in stacked
histograms. The bottom part of the figure shows both the
di↵erence and the ratio between data and non-oscillation hypothesis
(black points), and between best fit prediction and
non-oscillation hypothesis (red solid histogram). . . . . . . . . 104