L
$_{3}$
-subshell alignment of Th and U ionized by
59.5 keV photons has been investigated by evaluating the angular dependence of
L
$_{i}$
(i=l, α, η, β and γ) X-ray lines.
The angular dependence measurements were performed by measuring the
fluorescence cross section, σ
$_{Li}$
(i=1, η,
α, β and γ) and
σ
$_{Ll}$
/σ
$_{Lγ}$
,
σ
$_{Lη}$
/σ
$_{Lγ }$
,
σ
$_{Lα}$
/σ
$_{Lγ }$
and σ
$_{Lβ}$
/σ
$_{Lγ}$
ratios at different angles. It was observed from the measurements that
L
$_{i}$
(i=l and α) X rays for the
L
$_{3}$
-subshell depended on the emission angle and had an
anisotropic spatial distribution. On the other hand, there was no dependence of
emission angle and any significant anisotropy for other L X rays. The both Ll
and Lα X-rays originate from the filling of vacancies in states
L
$_{3}$
-subshell with J =3/2. The results of measurements
indicate that the L
$_{3}$
-subshell vacancy states with J = 3/2
are aligned, whereas L
$_{1}$
, and L
$_{2}$
vacancy states with J =1/2 are non-aligned. Integral cross-sections for the
L
$_{i}$
(i=l, η, α, β and γ) X-rays and L
subshell fluorescence yields ω
$_{i}$
(i= 1, 2 and 3)
were also determined and results were compared with theoretically calculated
values and results of others and fairly good correspondence was observed.
