The Transient Magnetic Field and its Application to the Measurement of Nuclear Magnetic Moments.
The velocity dependence of the transient hyperfine magnetic field at swift Sm ions traversing thin iron foils has been determined over the velocity range 0.014 < v/c < 0.027. The transient field has been shown to increase with velocity but the dependence is not linear. The field at ('16)O ions stopping in thick iron foils has been measured and exhibits a non-linear velocity dependence. The results are consistent with recent measurements of K-vacancies that are produced inside the moving ion, and thus support a model of transient hyperfine fields based on the existence of bound, polarized unpaired electrons in the moving ion. All available data on transient field measurements at ions with 8 < Z < 78, traversing thin iron foils were compiled and simultaneously fitted to a general parametrization of the field. The scaling of the field strength with host magnetization was reconfirmed with the results showing no detectable preferential electron loss mechanism to be present. The "thin foil" technique was applied towards the measurement of the g-factors of pi-cosecond lifetime states of even-even nuclei, using the derived general parametrization to represent the field. The following g-factors have been measured:. g(('46)Ti,2(,1)('+)) = 0.49 (+OR-) 0.12. g(('48)Ti,2(,1)('+)) = 0.43 (+OR-) 0.19. g(('120)Te,2(,1)('+)) = 0.29 (+OR-) 0.03. g(('122)Te,2(,1)('+)) = 0.33 (+OR-) 0.03. g(('124)Te,2(,1)('+)) = 0.26 (+OR-) 0.03. g(('126)Te,2(,1)('+)) = 0.19 (+OR-) 0.03. g(('128)Te,2(,1)('+)) = 0.31 (+OR-) 0.04. g(('130)Te,2(,1)('+)) = 0.29 (+OR-) 0.06. g(('130)Ba,2(,1)('+)) = 0.35 (+OR-) 0.03. g(('132)Ba,2(,1)('+)) = 0.34 (+OR-) 0.03. g(('134)Ba,2(,1)('+)) = 0.43 (+OR-) 0.05. g(('136)Ba,2(,1)('+)) = 0.34 (+OR-) 0.05. g(('186)Os,2(,1)('+)) = 0.262 (+OR-) 0.013. g(('188)Os,2(,1)('+)) = 0.300 (+OR-) 0.012. g(('194)Pt,2(,1)('+)) = 0.160 (+OR-) 0.014. The g-factors of the Ti isotopes are consistent with shell model caculations which cannot be distinguished from collective model estimates. The g-factors of the Te isotopes are in good agreement with quasiparticle calculations but are in disagreement with first order Interacting Boson Approximation Model predictions. The g-factors of the Ba isotopes have been found to be consistent with collective model estimates. The g-factors of the Os isotopes have been measured to provide a calibration of the transient field at ('194)Pt whose g-factor appears to be anomalously lower than reported values.
- Pub Date:
- Physics: Nuclear