Definition study for photovoltaic residential prototype system

A site evaluation was performed to assess the relative merits of different regions of the country in terms of the suitability for experimental photovoltaic powered residences. Eight sites were selected based on evaluation criteria which included population, photovoltaic systems performance and the cost of electrical energy. A parametric sensitivity analysis was performed for four selected site locations. Analytical models were developed for four different power system implementation approaches. Using the model which represents a direct (or float) charge system implementation the performance sensitivity to the following parameter variations is reported: (1) solar roof slope angle; (2) ratio of the number of series cells in the solar array to the number of series cells in the lead-acid battery; and (3) battery size. For a Cleveland site location, a system with no on site energy storage and with a maximum power tracking inverter which feeds back excess power to the utility was shown to have 19 percent greater net system output than the second place system. The experiment test plan is described. The load control and data acquisition system and the data display panel for the residence are discussed

Experimentation and Modeling of Laser Radiation Scattering Through Carbon Fiber Reinforced Polymers

With the prevalence of carbon fiber reinforced polymers (CFRPs) in aerospace platforms, there is a need to better understand radiative heat transport through the material. A laboratory experiment was constructed and a computational zonal Monte Carlo (ZMC) model developed to quantify and understand the laser scattering properties of CFRPs. The ZMC model builds off of the zonal method (ZM)—developed by Hottel et al. and expanded by researchers such as Yuen et al.—by incorporating Monte Carlo techniques into the ZM. The ZMC method is superior in efficiency to the ZM and alternative ray tracing methods, which enables larger mediums of exchange to be analyzed. A laser experiment was constructed using a commercial off-the shelf 1.26 kW ytterbium fiber laser (run at 70 W in this thesis) with customized optics to focus the beam into a vacuum chamber, as well as photodiodes, thermocouples, an IR camera and pyrometer for temperature, reflection and transmissivity measurements. Transmission data were analyzed using the ZMC method to determine CFRP albedo and extinction coefficients, which can be utilized for platform-level aerospace models to predict heat transfer more accurately through CFRP structures. Specifically, these optical properties can be read into multi-physics tools such as COMSOL to better predict radiation scattering through CFRP. Matching laser radiation scattering to CFRP test data has not been done before and provides validation to optical property predictions. The effects of nodal, substrate and detector plane sizing, as well as laser beam parameters, were also studied and optimized when matching albedo and extinction coefficient predictions from the ZMC method to experimental test data. Average albedo values for IM7/977-3 CFRP using the anchored ZMC method are 0.78 and 0.81 with one-ply and two-ply samples, respectively, having standard deviations of 0.11 and 0.09. Extinction coefficient predictions are 109.4 and 93.8 cm-1 with standard deviations of 28.3 and 18.8 cm-1 for one-ply and two-ply samples. When these optical properties are incorporated into multi-physic models and scaled up to larger aerospace platforms, this increased radiation transport accuracy will lead to a better understanding of laser-material interactions and burn-through times

Evidence of world-wide submergence

At the beginning of the century geologists were discussing the idea that the glacial period was the result of enormous vertical movements of the continents. Uplifts were said to have cooled the climates, bringing on glaciation, and subsequent subm~rgence caused the glaciers to melt. This hypothesis was supported by the finding of deep canyons on the sea floor which indicated the former elevated condition of the continents...

Multiple Charge State Beam Acceleration at Atlas

A test of the acceleration of multiple charge-state uranium beams was performed at the ATLAS accelerator. A 238U+26 beam was accelerated in the ATLAS PII linac to 286 MeV (~1.2 MeV/u) and stripped in a carbon foil located 0.5 m from the entrance of the ATLAS Booster section. A 58Ni9+ 'guide' beam from the tandem injector was used to tune the Booster for 238U+38. All charge states from the stripping were injected into the booster and accelerated. Up to 94% of the beam was accelerated through the Booster linac, with losses mostly in the lower charge states. The measured beam properties of each charge state and a comparison to numerical simulations are reported in this paper.Comment: LINAC2000, MOD0

Heavy-Ion Beam Acceleration of Two-Charge States from an Ecr Ion Source

This paper describes a design for the front end of a superconducting (SC) ion linac which can accept and simultaneously accelerate two charge states of uranium from an ECR ion source. This mode of operation increases the beam current available for the heaviest ions by a factor of two. We discuss the 12 MeV/u prestripper section of the Rare Isotope Accelerator (RIA) driver linac including the LEBT, RFQ, MEBT and SC sections, with a total voltage of 112 MV. The LEBT consists of two bunchers and electrostatic quadrupoles. The fundamental frequency of both bunchers is half of the RFQ frequency. The first buncher is a multiharmonic buncher, designed to accept more than 80% of each charge state and to form bunches of extremely low longitudinal emittance (rms emittance is lower than 0.2 keV/u nsec) at the output of the RFQ. The second buncher is located directly in front of the RFQ and matches the velocity of each charge-state bunch to the design input velocity of the RFQ. We present full 3D simulations of a two-charge-state uranium beam including space charge forces in the LEBT and RFQ, realistic distributions of all electric and magnetic fields along the whole prestripper linac, and the effects of errors, evaluated for several design options for the prestripper linac. The results indicate that it is possible to accelerate two charge states while keeping emittance growth within tolerable limits.Comment: LINAC2000, MOD0