Numerical simulation of mather, filippov and concentric plasma focus using Lee model

In this study, numerical simulations of concentric, Mather and Filippov dense plasma focus (DPF) devices using Lee Model have been performed to test the universality of Lee Model. It includes the configuring of the Lee Model Code to work as any DPF devices from measured current waveform to modelling for diagnostics, evolution of the diagnostics-time histories for the dynamics, energies and plasma properties computed from the measured total current waveform by the code. DPF is a potential source of neutrons. The current research focus is on computing the neutron yield,Yn, from DPF by numerical experiments. Published experimental results from these DPF are then compared and analyzed with numerical simulations results in terms of Yn at different operational parameters. The numerical simulations were executed using the 5-phase Lee Model Code version RADPFV5.15de. The computed Yn from a concentric deuterium-tritium KPU-200 DPF is 1.44 X 1013 neutrons per shot at pressure 14.25 Torr and charging voltage 47.7 kV. For the 1.4 kJ DPF, the optimum, Yn was 2.9 X 107 neutrons/shot at 5.5 Torr deuterium pressure. The optimum computed Yn for 11.2 kJDPF at 4.1 Torr was 1.447 X 10s neutrons/shot. For 28.8 kJ device, the optimum computed Yn of 1.24 X 109neutrons/shot was obtained at 2.2 Torr deuterium pressure at 20 kV. For the 480 kJ device, the optimum yield of 1.8 X 1011 neutrons/shot was obtained at pressure 7.6 Torr and charging voltage of 27 kV. Analysis of the results shows that the optimum Yn was achieved only at optimum operating conditions. For the Dena Filippov DPF with discharge energies of 5 kJ and 90 kJ at pressures ranging from 0.1 Torr to 2.5 Torr, the computed Yn is 1.5 X 109 neutrons/shot in agreement with the experimental result of 1.2 X 109 neutrons/shot using deuterium gas. The computed Yn of Iranian First Filippov Type Plasma Focus (IFFT-PF) with deuterium as working gas at pressure of 0.6 Torr is 3.4 X 106 neutrons/shot as compared to the published value o f 3 . 1 x l 0 6 neutrons/shot. These results show that the computed Yn is in good agreement with the measured Yn at charging voltage of 16 kV for Dena device and 26 kV for IFFT-PF. The modelling, results and applications of the Lee Model code are of profound interest

Research opportunities with compact accelerator-driven neutron sources

Since the discovery of the neutron in 1934 neutron beams have been used in a very broad range of applications, As an aging fleet of nuclear reactor sources is retired the use of compact accelerator–driven neutron sources (CANS) are becoming more prevalent. CANS are playing a significant and expanding role in research and development in science and engineering, as well as in education and training. In the realm of multidisciplinary applications, CANS offer opportunities over a wide range of technical utilization, from interrogation of civil structures to medical therapy to cultural heritage study. This paper aims to provide the first comprehensive overview of the history, current status of operation, and ongoing development of CANS worldwide. The basic physics and engineering regarding neutron production by accelerators, target-moderator systems, and beam line instrumentation are introduced, followed by an extensive discussion of various evolving applications currently exploited at CANS

Towards a Universal Two-Qubit Gate with Self-Assembled InAs Quantum Dot Molecules.

Recent studies in self-assembled InAs quantum dots (QDs) for applications in quantum information processing have demonstrated initialization, readout and long decoherence time of an electron spin confined in a single QD. These arguably fulfill three out of the five DiVincenzo criteria for the physical implementation of quantum computation. Based on recent developments self-assembled InAs quantum dot molecules (QDMs), several advancements in the optical manipulation of two-electron spin states have been made. As a continuation of these studies towards a full two-qubit system, this thesis addresses one of the remaining criteria concerning a universal set of quantum gates. The physical platform for two-qubit gates is provided by two electrons confined in the QDM where the Coulomb exchange interaction gives rise to the singlet and triplet manifolds. In a transverse magnetic field, an eight-level system consisting of four singlet-triplet spin states, four optical excited states and twelve dipole allowed transitions arises. Spin initialization via multi-laser optical pumping is demonstrated with near unity fidelity for three of the spin states, while the remaining one can, in principle, be achieved by coherent optical pumping using four CW lasers. The effects of dynamic nuclear spin polarization, arising from the coupling between the electrons and the surrounding nuclei, is evident in the frequency pulling and pushing lineshapes in absorption profiles. This thesis shows that the optical nuclear spin locking that was demonstrated in a single QD earlier is effective in QDMs, yielding a long spin decoherence time of about 1 microsecond. Spectroscopic evidence suggests that this is accompanied by the first evidence of a narrowing in the Overhauser field distribution. The results reveal that stabilization of nuclear spin polarization in both QDs is achieved by optical manipulations in the top QD, demonstrating the effect of non-local nuclear spin locking. Finally, it is shown theoretically that pulsed excitation results in single spin rotations and in conjunction with the Coulomb exchange interaction, provides the ingredients for a universal two-qubit gate. A feasible experimental demonstration of the two-qubit gate is proposed, along with the methodology for the population readout of individual spin states.PhDElectrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/113477/1/colinmec_1.pd

First International Conference on Laboratory Research for Planetary Atmospheres

Proceedings of the First International Conference on Laboratory Research for Planetary Atmospheres are presented. The covered areas of research include: photon spectroscopy, chemical kinetics, thermodynamics, and charged particle interactions. This report contains the 12 invited papers, 27 contributed poster papers, and 5 plenary review papers presented at the conference. A list of attendees and a reprint of the Report of the Subgroup on Strategies for Planetary Atmospheres Exploration (SPASE) are provided in two appendices

Small business innovation research. Abstracts of 1988 phase 1 awards

Non-proprietary proposal abstracts of Phase 1 Small Business Innovation Research (SBIR) projects supported by NASA are presented. Projects in the fields of aeronautical propulsion, aerodynamics, acoustics, aircraft systems, materials and structures, teleoperators and robots, computer sciences, information systems, data processing, spacecraft propulsion, bioastronautics, satellite communication, and space processing are covered

Combined cell and nanoparticle models for TOPAS to study radiation dose enhancement in cell organelles

Dose enhancement by gold nanoparticles (AuNP) increases the biological effectiveness of radiation damage in biomolecules and tissue. To apply them effectively during cancer therapy their influence on the locally delivered dose has to be determined. Hereby, the AuNP locations strongly influence the energy deposit in the nucleus, mitochondria, membrane and the cytosol of the targeted cells. To estimate these effects, particle scattering simulations are applied. In general, different approaches for modeling the AuNP and their distribution within the cell are possible. In this work, two newly developed continuous and discrete-geometric models for simulations of AuNP in cells are presented. These models are applicable to simulations of internal emitters and external radiation sources. Most of the current studies on AuNP focus on external beam therapy. In contrast, we apply the presented models in Monte-Carlo particle scattering simulations to characterize the energy deposit in cell organelles by radioactive 198AuNP. They emit beta and gamma rays and are therefore considered for applications with solid tumors. Differences in local dose enhancement between randomly distributed and nucleus targeted nanoparticles are compared. Hereby nucleus targeted nanoparticels showed a strong local dose enhancement in the radio sensitive nucleus. These results are the foundation for future experimental work which aims to obtain a mechanistic understanding of cell death induced by radioactive 198Au

Air Force Institute of Technology Research Report 2013

This report summarizes the research activities of the Air Force Institute of Technology’s Graduate School of Engineering and Management. It describes research interests and faculty expertise; lists student theses/dissertations; identifies research sponsors and contributions; and outlines the procedures for contacting the school. Included in the report are: faculty publications, conference presentations, consultations, and funded research projects. Research was conducted in the areas of Aeronautical and Astronautical Engineering, Electrical Engineering and Electro-Optics, Computer Engineering and Computer Science, Systems Engineering and Management, Operational Sciences, Mathematics, Statistics and Engineering Physics