Evidence for Transient Hyperfine Fields on Fast Ions in Ferromagnetic Media

Magnetic Dipole Moments of Excited Nuclear States

“…A typical backscattered , article spectrum for a heavy target on a lighter backing is shown in Figure 3a, while Figure 13b shows a representative 0+ � 2+ �O+ angular dis ribution using a diamagnetic metal host. Other -y and particle spectra, as rell as various -y-ray angular distributions, can be seen in (87)(88)(89)(90)(91)(92)(93)(94)(95)(96)(97)(98)(99)(100) .…”

“…We note briefly that two explanations have been advanced. The first is an ad hoc phenomenological model ascribing the transient effect to the Fermi-Segre contaCt field arising from the pickUp of polarized electrons from the host as the recoil slows down (89,98) . The second is a quantitative theory (142) ascribing the transient field to the Coulomb scattering of the nearly free, polarized, host electrons by the nucleus of the recoil.…”

“…The data given in (98) were analyzed before the Ge results were obtained and one could only conclude that 7 1 <5 psec. The deduction of g factors of short-lived states then depended critically on the time dependence of HI.…”

Using magnetic moments to study the nuclear structure of I ≥ 2 states

“…The Transient Field effect was ¿rst reported in 1968, by Borchers and collaborators, in nuclear magnetic moment measurements of ions when implanted in ferromagnetic materials [9]. An anomalous precession was only observed before the ions came to a stop inside the ferromagnetic host material, that let to the name "transient".…”

Calibration of the transient field for Pt ions in gadolinium and magnetic moments of the21+states inPt

“…The discovery [1] of large magnetic fields that act on ions as they travel through iron, cobalt, nickel, and gadolinium has led to the development of techniques [2,3] for the measurement of magnetic moments of shortlived excited nuclear states. These techniques employ the detection of the hyperfine interaction between the electronic environment and the nuclear moments of excited nuclei as they traverse thin polarized ferromagnetic foils.…”