ATOMIC PHYSICS RESEARCHES AT COOLER STORAGE RING IN LANZHOU

The commissioning of the cooler storage rings (CSR) was successful, and the facility provides new possibilities for atomic physics with highly charged ions. Bare carbon, argon ions, were successfully stored in the main ring CSRm, cooled by cold electron beam, and accelerated up to 1 GeV/u. Heavier ions as Xe44+ and Kr28+ were also successfully stored in the CSRs. Both of the rings are equipped with new generation of electron coolers which can provide different electron beam density distributions. Electron-ion interactions, high precision X-ray spectroscopy, complete kinematical measurements for relativistic ion-atom collisions will be performed at CSRs. Laser cooling of heavy ions are planned as well. The physics programs and the present status will be summarized.

Extracting single-particle information for the superheavy mass region by studying excited structure in transfermium nuclei

Recent experimental advances have made it possible to study spectroscopy in very heavy nuclei. We show that from the excited high-spin structure of transfermium isotopes, one may gain useful information on single-particle states for the superheavy mass region, which is the key to locating the anticipated 'island of stability'. In this work, we employ the Projected Shell Model for Cf, Fm, and No isotopes to study rotation alignment of the particles that occupy particular high-j intruder orbitals.

Investigation of various growth mechanisms of solid tumour growth within the linear-quadratic model for radiotherapy

The standard linear-quadratic survival model for radiotherapy is used to investigate different schedules of radiation treatment planning to study how these may be affected by different tumour repopulation kinetics between treatments.

Damage to plasmid DNA induced by low energy carbon ions

The damage induced in supercoiled plasmid DNA molecules by 1-6 keV carbon ions has been investigated as a function of ion exposure, energy and charge state. The production of short linear fragments through multiple double strand breaks has been demonstrated and exponential exposure responses for each of the topoisomers have been found. The cross section for the loss of supercoiling was calculated to be (2.2 +/- 0.5) x 10(-14) cm(2) for 2 keVC(+) ions. For singly charged carbon ions, increased damage was observed with increasing ion energy. In the case of 2 keV doubly charged ions, the damage was greater than for singly charged ions of the same energy. These observations demonstrate that ion induced damage is a function of both the kinetic and potential energies of the ion.

FDTD analysis of close-coupled 418 MHz radiating devices for human biotelemetry

This paper describes the finite-difference time-domain (FDTD) analysis of antenna-body interaction effects occurring when chest-mounted 418 MHz radio transmitters are used for medical telemetry applications. Whole-body software models (homogeneous, layered and tissue-segmented) were developed for an adult male subject. Using an electrically small (300 mm(2)) planar loop antenna, calculated radiation efficiencies ranged between 33.5% and 39.2% for a whole-body model, and between 60.7% and 66.1% for a torso; radiation patterns were found to be largely independent of model composition. The computed radiation efficiency for a 21.5 kg phantom representing a six-year-old female was within 1.1 dB of measured results (actual body mass 28 kg) and well-correlated azimuthal radiation patterns were noted.

Particle swarm optimization for two-connected networks with bounded rings

The Two-Connected Network with Bounded Ring (2CNBR) problem is a network design problem addressing the connection of servers to create a survivable network with limited redirections in the event of failures. Particle Swarm Optimization (PSO) is a stochastic population-based optimization technique modeled on the social behaviour of flocking birds or schooling fish. This thesis applies PSO to the 2CNBR problem. As PSO is originally designed to handle a continuous solution space, modification of the algorithm was necessary in order to adapt it for such a highly constrained discrete combinatorial optimization problem. Presented are an indirect transcription scheme for applying PSO to such discrete optimization problems and an oscillating mechanism for averting stagnation.

Sum rules and correlations in asymmetric nuclear matter

The neutron and proton single-particle spectral functions in asymmetric nuclear matter fulfill energy-weighted sum rules. The validity of these sum rules within the self-consistent Green's function approach is investigated. The various contributions to these sum rules and their convergence as a function of energy provide information about correlations induced by the realistic interaction between the nucleons. The study of the sum rules in asymmetric nuclear matter exhibits the isospin dependence of the nucleon-nucleon correlations.