[en] The EOS TPC was constructed for complete event measurement of heavy ion collisions at the Bevalac. We report here on the TPC design and some preliminary measurements of conserved event quantities such as total invariant mass, total momentum, total A and Z

[en] The energy spectra of deuterons emitted by nuclei (²⁷Al, ⁶³Cu, ⁹⁰Zr, /sup nat/Ta, ¹⁹⁷Au, and ²⁰⁸Pb) when bombarded by 45 MeV deuterons have been measured at a number of angles. Measurements have also been made for deuterons emitted from nuclei (⁶⁶Zn, ⁸⁹Y, ¹⁰²Pd and ¹⁰⁷Ag) when bombarded by 22 MeV deuterons. Deuterons with a range of energies from the Coulomb barrier of the heavier targets to the elastic energy were detected and identified with dE/dx-E semi-conductor telescopes. Sparse angular distributions and total inelastic cross sections were extracted. The double differential cross sections are forward peaked as a result of predominantly direct inelastic scattering. The total inelastic cross sections have little dependence on target mass. Attempts have been made to explain the smooth spectra in terms of a sum of collective multipole excitations in which the amplitudes have been determined with the help of energy weighted sum rules. The predicted cross sections using this approach qualitatively reproduce a number of features of the data but numerical comparisons are often off as much as a factor of two

[en] A large TPC is a main element in the STAR detector system to be used at RHIC. The TPC will provide dE/dx and tracking for the expected 4000 charged particles emitted in the pseudo rapidity window of -1 < η < +1. Much of the design work has been completed on this detector and prototyping is underway. We will report on the design of this TPC and present results of prototype tests of the pad plane structure that reads out the TPC. We are investigating the use of alternative gases to improved two track resolution and momentum resolution. A new method for providing spatial calibrations with fixed photoelectric sources in the TPC is also being developed. Results of these studies will be reported

[en] The reaction ¹⁴C(³He,n)¹⁶O has been measured at a ³He bombarding energy of 25.4 MeV. The zero-degree differential cross section for the excitation of the three low lying 0⁺ T = 0 states, at energies 0.0, 6.05 and 12.05 MeV are, respectively, 1.33 +- 0.10, 0.49 +- 0.10, and 0.50 +- 0.10 mb/sr. These measured cross sections are in rough agreement with single-step zero-range DWBA calculations using an empirically determined ¹⁴C ground state wave function and in which the Brown and Green coexistence-model wave functions are used to describe the ¹⁶O 0⁺ states. The angular distribution of the transition to the ground state is measured between 0⁺ and 32⁰. (orig.)

[en] A high-voltage beam deflector driven at a sub-multiple of the cyclotron frequency has been developed to reduce the beam repetition rate of the University of Colorado cyclotron to allow long flight path time of flight measurements. The design uses readily available semiconductor components for control and drive and an Eimac 4CX1000A power amplifier. Accepted beam bursts pass through the deflection plates at a time when the voltage difference and its first derivative are zero so that voltage and phase stability requirements are relaxed and beamline retuning is not needed. (Auth.)

No abstract available

[en] Low energy nuclear fragments (12< or =A< or =140) from the bombardment of Au by high energy protons, ⁴He, and ²⁰Ne projectiles are measured to yield information on the breakup of the target nucleus. We discuss the shapes of the fragment energy spectra across this broad range of fragment mass and pick out the fission component by its binary breakup. Multiplicities of coincident fast charged particles are presented as a measure of the degree of violence of the initial stage of the collision. Angular distributions of light fragments (8< or =Z< or =11) give the average velocities imparted to the residue in central collisions, and these values are compared to the results of cascade calculations. Measurements of slow fragment multiplicities from central events reveal a many-fragment final state. In the light of this finding we develop a simple calculation of the Coulomb features of the observed spectra. The applicability of a statistical breakup model is discussed

[en] There is an awakening of theoretical interest in the mechanisms by which nuclear fragments (4 less than or equal to A less than or equal to 150) are produced in violent collisions of heavy ions. With this in mind we review some aspects of the available experimental data and point out some challenging features against which to test the models. The concept of evaporation is tremendously powerful when applied to pieces of nuclei of low excitation (1 or 2 MeV/u). Current interest focuses on higher excitations, at the point where the binding energy of the system vanishes. This is the transition from liquid nuclei to a gas of nucleons, and it may be that the critical phenomena that certainly exist in infinite nuclear matter will be manifest in finite nuclei under these conditions

[en] A typical spectrum from the reaction ¹⁶O + Be → ⁹Be + X is shown. Angular distributions for the production of N and Be isotopes in the ¹⁶O + Al reaction are presented; there is a more rapid fall-off with angle for the heavier isotopes. Widths of fragment momentum spectra are plotted as a function of fragment mass in the projectile frame for ¹⁶O + Au, Be; these results show sharp disagreement with the systematics of momentum widths observed at other energies. 3 figures

[en] This paper reports on an expert system for generating control rod patterns that has been developed. The knowledge is transformed into IF-THEN rules. The inference engine uses the Rete pattern matching algorithm to match facts, and rule premises and conflict resolution strategies to make the system function intelligently. A forward-chaining mechanism is adopted in the inference engine. The system is implemented in the Common Lisp programming language. The three-dimensional core simulation model performs the core status and burnup calculations. The system is successfully demonstrated by generating control rod programming for the 2894-MW (thermal) Kuosheng nuclear power plant in Taiwan. The computing time is tremendously reduced compared to programs using mathematical methods