Determination of the g-factor for several short-lived nuclear states
The g-factors of nine excited nuclear states have been measured by observing the rotation of the angular correlation of a γ-γ cascade in a magnetic field whose direction was alternately switched up and down with respect to the plane of the measurement. The results are: 280-kev state of As^(75) (τ...
| Summary: | The g-factors of nine excited nuclear states have been measured
by observing the rotation of the angular correlation of a γ-γ cascade in a magnetic field whose direction was alternately switched
up and down with respect to the plane of the measurement. The results
are: 280-kev state of As^(75) (τ = 4 x 10^(-10) sec) g = (0.39 ±
0.12); 9l-kev state of pm^(147) (τ = 3.4 x 10^(-9) sec) g = (0.93 ± 0.20)/
G_2 where G_2 is between 0.5 and 1.0 ; 118-kev state of Tm^(169)
(τ = 9.0 x 10^(-11) sec) g = (0.21 ± 0.07) ; 114-kev state of Lu^(175) (τ = 9.4 x 10^(-11) sec) g = (0.65 ± 0.25); 113-kev state of Hf^(177) (τ =
7 x 10^(-10) sec) g = (0.20 ± 0.06) ; l22-kev state of Sm^(152) (τ = 2.0 x 10^(-9) sec) g = (0.28 ± 0.07); 123-kev state of Gd^(154) (τ = 1.7 x 10^(-9)
sec) g = (0.4 ± 0.5); 87-kev state of Dy^(160) (τ = 2.6 x 10^(- 9) sec) g =
(0.28 ± 0.08) ; 8l-kev state of Er^(166) (τ = 2.4x 10 ^(-9) sec) g = (0.31 ±
0.06). The measurements have been compared to theoretical predictions.
On the basis of the shell model, the probable value of the
spin for the 9l-kev level of Pm^(147) is 5/2+. The results for Tm^(169),
Lu^(175), and Hf^(177) have been interpreted using the Nilsson model.
The results found are in qualitative agreement with theory, but some
deviations, especially in Hf^(177), are noted. The measurements for
the 2+ states 0f Sm^(152), Dy^(160), and Er^(166) provide a direct eva1uation
of the rotational g-factor, g_R, of the collective model. The
values found are about 3/4 of the value g_R = Z/A predicted for uniform
nuclear flow. The effects of electronic paramagnetism in rare
earths on these measurements are treated in an appendix. The assumptions
necessary to interpret the observed rotation in terms of
the g-factor are discussed.
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