Abstract
Measurements of the conversion electron spectrum from the
167Er(n, e
−)
168Er reaction show
L
I
L
III
= 0.0859(6)
,
L
II
L
III
= 0.963(4)
,
M
I
M
III
= 0.696(7)
, and
M
II
M
III
= 0.934(5)
for the 79.804 keV, 2
+ → 0
+, E2 transition and
L
I
L
III
= 0.663(4)
,
L
II
L
III
= 1.270(6)
for the 184.285 keV, 4
+ →
+, E2 transition in
168Er. For the 79.8 keV transition the
L
II
L
III
ratio is (5.7 ± 0.7)% higher and the
M
I
M
III
ratio (7.0 ± 1.1)% lower than predicted by theory. The
L
II
L
III
and
M
II
M
III
ratios for this transiton and the
L-subshell ratios of the 184 keV transition agree with the theory. An explanation of the observed discrepancies is sought in the sensitivity of the calculated
L
I and
M
I conversion coefficients on the lower energy region to a partical cancellation in the leading matrix element for E2 conversion.