An Introduction to Neutron Scattering - Spallation Neutron Source

Reflection of Neutrons by a Smooth Surface: Fresnel’s Law
n = 1-λ 2 ρ/2π
T
T
R
R
I
I
T
R
I
k
a
k
a
k
a
a
a
a
r
r
r
&
=
+
=
+
⇒
=
(1)
0
z
at
&
of
continuity
ψ
ψ
)
/(
)
(
/
by
given
is
e
reflectanc
so
sin
sin
sin
sin
)
(
)
(
(3)
&
(1)
cos
cos
:
Law
s
Snell'
(2)
&
(1)
(3)
sin
sin
)
(
(2)
cos
cos
cos
:
surface
the
to
parallel
and
lar
perpendicu
components
Tz
Iz
Tz
Iz
I
R
Iz
Tz
R
I
R
I
T
R
I
T
R
I
k
k
k
k
a
a
r
k
k
n
a
a
a
a
n
nk
a
k
a
a
nk
a
k
a
k
a
+
−
=
=
=
′
≈
′
=
+
−
=>
′
=
=>
′
−
=
−
−
′
=
+
α
α
α
α
α
α
α
α
α
α
α