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Excited state measurements in Ta-181 and Dy-161

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Title Excited state measurements in Ta-181 and Dy-161
Names Blackburn, Wildon Charles (creator)
Easterday, Harry T. (advisor)
Date Issued 1966-05-12 (iso8601)
Note Graduation date: 1966
Abstract The g-factor of the 482 Key (Kiloelectron volt) state in Ta¹⁸¹
and the half-lives of the 25.6 Key and 74.5 Key states in Dy¹⁶¹ have
been measured by the delayed coincidence method. The g-factor of
the 482 Key state in Ta¹⁸¹ was determined by observing the effects
of an external magnetic field on the angular correlation of the 133-482 Key gamma-ray cascade. A liquid source known to exhibit the
unperturbed angular correlation was used. The source was prepared
by dissolving neutron irradiated hafnium metal in 27N hydrofluoric
acid. There have been a number of determinations of the g-factor
for this level by the differential-delay and integral methods; while
giving information of a more detailed nature than the integral method,
the main advantage of the differential method is that it yields the interaction
strength directly, independent of the lifetime of the state.
The value of 1.32 + 0.04 obtained for the g-factor in this investigation
is consistent with previous determinations.
The Dy¹⁶¹ source was polycrystalline in the form of the oxide
and was formed by the chain decay of neutron irradiated Gd₂O₃. A
measurement of the anisotropy revealed that during the interval of
interest, and within the limits of statistical fluctuations, there were
no time-dependent interactions tending to reorient the nuclei. The
slope of the delayed coincidence curve sufficiently far removed from
zero time yielded the value of 27.78 + 0.28 ns (Nanoseconds) for the
half-life of the state intermediate to the 48.9 - 25.6 Key transition
and agrees well with the results of previous determinations. The
evaluation of data by a method of numerical integration was required
for the determination of the lifetime of the state intermediate to the
57.2 - 74.5 Key transition due to the effects of finite time resolution.
This yielded a value of 2.91 + 0.26 ns, which also was consistent with
the results of measurements by other methods.
Genre Thesis/Dissertation
Topic Tantalum
Identifier http://hdl.handle.net/1957/47777

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