TY - JOUR
TI - Study of Low-Lying Levels of 37Ar
AU - Ragan, C. E.
AU - Gould, C. R.
AU - Roberson, N. R.
AU - Mitchell, G. E.
AU - Tilley, D. R.
T2 - Physical Review C
AB - The mean lifetimes of the levels of $^{37}\mathrm{Ar}$ below 3.0-MeV excitation energy have been measured by applying the Doppler-shift-attenuation method to the $^{34}\mathrm{S}(\ensuremath{\alpha},n)^{37}\mathrm{Ar}$ reaction (${Q}_{0}=\ensuremath{-}4.629$ MeV). A 450-\ensuremath{\mu}g/c${\mathrm{m}}^{2}$ CdS target (enriched to 85.61% in $^{34}\mathrm{S}$) evaporated onto a 1-\ensuremath{\mu} Ni foil was bombarded with $\ensuremath{\alpha}$ particles ranging in energy from 7.6 to 8.8 MeV. $\ensuremath{\gamma}$ rays were detected at 0, 37, 45, 55, 90, and 143\ifmmode^\circ\else\textdegree\fi{} to the beam axis with a 30-cc Ge(Li) detector. The following mean lifetimes were found: $\ensuremath{\tau}(1.41\ensuremath{-}\mathrm{M}\mathrm{e}\mathrm{V}\phantom{\rule{0ex}{0ex}}\mathrm{l}\mathrm{e}\mathrm{v}\mathrm{e}\mathrm{l})={1.08}_{\ensuremath{-}0.13}^{+0.17}$ psec, $\ensuremath{\tau}(2.22)=380\ifmmode\pm\else\textpm\fi{}50$ fsec, $\ensuremath{\tau}(2.49)={775}_{\ensuremath{-}89}^{+105}$ fsec, and $\ensuremath{\tau}(2.80)=14\ifmmode\pm\else\textpm\fi{}11$ fsec. Excitation energies for the first five excited states were determined from the ground-state transitions. All five levels were found to undergo $\ensuremath{\gamma}$ decay 100% to the ground state; upper limits were set on other possible transitions. Analysis of the $\ensuremath{\gamma}$-ray angular distributions for the levels at 1.61 and 2.49 MeV gave spins in agreement with previous assignments. The angular-distribution and lifetime measurements yield a most probable spin-parity assignment of (${\frac{7}{2}}^{+}$) for the 2.22-MeV level. The experimental transition strengths for the positive-parity states are in good agreement with predictions of many-particle shell-model calculations.
DA - 1971/3/1/
PY - 1971/3/1/
DO - 10.1103/physrevc.3.1152
VL - 3
IS - 3
SP - 1152–1161
SN - 0556-2813
UR - http://dx.doi.org/10.1103/physrevc.3.1152
ER -
TY - JOUR
TI - Mean Lifetime of the 1.61-MeV Level in 37Ar
AU - Ragan, C. E.
AU - Mitchell, G. E.
AU - Tilley, D. R.
AU - Gould, C. R.
AU - Roberson, N. R.
T2 - Physical Review C
DA - 1971/5/1/
PY - 1971/5/1/
DO - 10.1103/physrevc.3.2076
VL - 3
IS - 5
SP - 2076–2078
SN - 0556-2813
UR - http://dx.doi.org/10.1103/physrevc.3.2076
ER -
TY - JOUR
TI - NUMERICAL FOURIER TRANSFORMS IN ONE, 2, AND 3 DIMENSIONS FOR LIQUID STATE CALCULATIONS
AU - LADO, F
T2 - JOURNAL OF COMPUTATIONAL PHYSICS
AB - When a Fourier transform (FT) is to be numerically computed and subsequently numerically inverted, perhaps repetitively, it is desirable that the algorithm used to accomplish this should maintain the orthogonal nature of the Fourier expansion. Algorithms with this property are derived here for the FT of central functions in one, two, and three dimensions. These rules for mechanical quadrature are similar to the trapezoidal rule, but with intervals determined by the zeros of the orthogonal basis functions. A numerical test using Gaussians shows a high accuracy in the computed transforms. The procedure can be extended to other Fourier-Bessel transforms.
DA - 1971///
PY - 1971///
DO - 10.1016/0021-9991(71)90021-0
VL - 8
IS - 3
SP - 417-&
SN - 0021-9991
ER -
TY - JOUR
TI - MONTE-CARLO CALCULATION OF NORMAL AND ABNORMAL DIFFUSION IN EHRENFESTS WIND-TREE MODEL
AU - WOOD, WW
AU - LADO, F
T2 - JOURNAL OF COMPUTATIONAL PHYSICS
AB - Numerical machine calculations combining the Monte Carlo and molecular dynamics methods are used to study the diffusion behavior in the two versions of Ehrenfest's wind-tree model recently studied by Hauge and Cohen. The mean-square displacement <Δr2> is found to be the most suitable variable for precise calculation, and its behavior as a function of time tends to confirm the findings of Hauge and Cohen: Namely, when the oriented square “trees” are allowed to overlap one another, the diffusion is “abnormal”, in that <Δr2> increases less rapidly than linearly in the time, so that the usual diffusion constant vanishes. When the oriented square “trees” are hard, i.e., non-overlapping, the diffusion appears to be normal.
DA - 1971///
PY - 1971///
DO - 10.1016/0021-9991(71)90109-4
VL - 7
IS - 3
SP - 528-&
SN - 0021-9991
ER -
TY - JOUR
TI - General approach to the lineshape problem in nuclear magnetic resonance
AU - Lado, F.
AU - Memory, J. D.
AU - Parker, G. W.
T2 - Physical Review. B, Condensed Matter and Materials Physics
DA - 1971///
PY - 1971///
VL - 4
SP - 1406-1422
ER -