Evolution Of Cascades Research Articles

Ion-beam mixing in pure and in immiscible copper bilayer systems

Ion-beam mixing was measured in immiscible Cu bilayer systems after Kr irradiation at 6 K and at 295 K. It was observed that for the systems which form miscible liquids but which have limited solid solubility, Cu-Nb and Cu-Bi, mixing occurs at 6 but not at 295 K. For a system which is not miscible in either the solid or liquid state, mixing does not occur at either 6 or 295 K. Mixing was also measured in pure Cu isotope bilayer specimens,63Cu–65Cu, to provide a standard for the other measurements. The results are interpreted on the basis of an atomistic model of ion beam mixing. The model assumes that point defects are created in the initial phases of the cascade evolution, and that these defects migrate during the later ‘thermal spike’ phase.

Comparison of Monte Carlo and analytical calculations in QCD

We compare two approaches to calculate the angular energy-energy correlation function in QCD. One uses an analytical calculation and the other a Monte Carlo simulation of a parton cascade evolution. Good agreement is found also when extrapolating to the TeV energy region.

Pacific Northwest AGU Meeting

The 30th AGU Pacific Northwest Regional Meeting was held September 29 to October 1, 1983, on the campus of Western Washington University, Bellingham, Wash. Approximately 125 attended the meeting, and 36 papers were presented. The meeting included two fields trips, five special symposia, and a banquet where keynote speaker Don Swanson presented “Dome building on Mt. St. Helens.”The meeting highlights included a symposium on Tertiary sedimentary basins of Washington and Oregon which revealed the importance of sedimentological studies for deciphering the timing and nature of accretionary processes in tectonically active areas. Geological and geophysical studies on the recent tectonics of the Juan de Fuca plate and nearby continent were presented by workers from the United States and Canada as well as ongoing studies for the evolution and character of the crystalline North Cascades of Washington and British Columbia.

A computer simulation of high energy density cascades

Multiple interaction computer simulations of bombardment cascades have been used to study the surface damage created by an ion. Qualitative information on the temporal evolution of the dynamic cascade is obtained from an animated movie of the process. A comparison is made between the final damage states of high energy-density trajectories. A number of ion-atom potential functions have been investigated over a wide range of ion energies. Only superficial differences are found.

Cascade evolution of spherically symmetric pulsons in multivacuum field theory models

Spherically symmetric oscillating solitons of a new type have been observed; their stability and instability regions have been found to be defined by the “potential relief” structure.

Radiation Damage and Hyperfine Interactions

This paper presents a partial review of radiation damage effects on hyperfine interaction (HFI) experiments, based on the Discussion Meeting on Radiation Damage and Hyperfine Interactions held at Dieppe (France) prior to the Uppsala Conference. This presentation is complementary to that of H. de Waard's contribution to this volume. The emphasis here is on the relevance of information obtained from heavy-ion stopping theory and standard radiation damage annealing studies to the understanding of recent HFI experiments. Damage cascade evolution, annealing behaviour, dose effects and impurity evolution are discussed.

Time dependence of radiation damage cascades

Abstract Equations describing the time-dependent evolution of heavy-ion radiation damage cascades are derived, and some numerical calculations are presented. The derivation is more rigorous than the usual time-independent one.