Publications by authors named "Arnold J Sierk"

To determine which nuclei may exhibit shape isomerism, we use a well-benchmarked macroscopic-microscopic model to calculate potential-energy surfaces as functions of spheroidal (epsilon{2}), hexadecapole (epsilon{4}), and axial-asymmetry (gamma) shape coordinates for 7206 nuclei from A=31 to A=290. We analyze these and identify the deformations and energies of all minima deeper than 0.2 MeV.

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The developmental version of MCNP5 has recently been extended to provide for continuous-energy transport of high-energy protons. This enhancement involves the incorporation of several significant new physics models into the code. Multiple Coulomb scattering is treated with an advanced model that takes account of projectile and nuclear target form factors.

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We present fission-barrier-height calculations for nuclei throughout the periodic table based on a realistic macroscopic-microscopic model. Compared to other calculations (i) we use a deformation space of a sufficiently high dimension, sampled densely enough to describe the relevant topography of the fission potential, (ii) we unambiguously find the physically relevant saddle points in this space, and (iii) we formulate our model so that we obtain continuity of the potential energy at the division point between a single system and separated fission fragments or colliding nuclei, allowing us to (iv) describe both fission-barrier heights and ground-state masses throughout the periodic table.

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