Browsing by Subject "accelerators"
Now showing 1 - 7 of 7
- Results Per Page
- Sort Options
Item The CEM-UT Rapid-Fire Compulsator Test Results and Performance Evaluation(IEEE, 1989-06) Perkins, D. E.; Pratap, S. B; Spann, M. L; Thelen, R. F; Werst, M. D.Since its inception in 1978, much attention has focused on compulsators as an alternative to capacitors and homopolar generators as a pulsed power supply. In addition to high voltage, high peak power, and large power densities, compulsators offer the advantage of supplying repetitive pulses without the need for external power conditioning. These repetitive power pulses are well suited for driving laser flashlamps, electromagnetic and electrothermal launchers, and particle beam accelerators. In April of 1986, fabrication and installation of a 1 megajoule (MJ) per pulse, rapid-fire compulsator was completed at the Center for Electromechanics at The University of Texas at Austin (CEM-UT). A test program was initiated and, since then, a substantial volume of machine performance data has been collected. This paper presents the mechanical and electrical performance data of the compulsator. Included are measurements of rotor critical frequency and bearing performance. Also shown are open circuit voltage characteristics and current waveform characteristics during discharge into low impedance loads.Item High Pressure Acceleration of an Arc-Driven Metal Slug in a Railgun(IEEE, 1985-06) Peterson, D.R.; Fowler, C.M.; Kerrisk, J.F.The successful acceleration in a railgun of an intact, arc-driven metal slug subjected to a peak pressure of - 0.7 GPa is described. The techniques and principles of accelerating metal slugs at very high pressures are reviewed. High pressure operation is required for applications requiring maximum velocity in guns of limited length. The development of metal projectiles is useful because of the availability of a wide range of properties such as strength, density, ductility, hardness and melting point. For example, high tensile strength and ductility make metal projectiles resistant to damage resulting from high-pressure demuzzling in comparison to ceramic projectiles which are characterized by enormous compressive strength, but low tensile strength and ductility. The electrical conductivity of metals necessitates the protection of metal projectiles from erosion by the armature current during acceleration. The problem of designing protective sabots of minimum mass and capable of operating at very high pressure is discussed.Item Hypervelocity Macroparticle Accelerator Experiments at CEM-UT(IEEE, 1991-01) Weeks, D. A.; Weldon, W. F.; Zowarka, Jr, R. C.Several railgun experiments designed to accelerate projectile masses of 2 to 5 g to velocities greater than 6 km/s were performed. Two parallel rail-type accelerators with 12.7 mm square bores were used for the experiments. One gun is 2 m long, has molybdenum rails and alumina ceramic insulators. The other is 1 m long, has molybdenum rails and granite insulators. The greatest velocity achieved to date during the experiments was 5.1 km/s. During the test program, the following ideas to enhance launcher performance were tested: stiff-gun structures to reduce plasma leakage and rail movement, refactory bore materials to reduce ablation and frictional losses, and prefilling the gun bore with gases which will eliminate precursor arcs. After three experiments utilizing the 2 m long launcher, with peak currents ranging from 660 to 780 kA, a gun barrel comprised of 96% pure alumina ceramic insulators and 99.9% pure molybdenum rails has survived with minimal damage and no degradation of sealsItem Linked but desynched: An OODA analysis of associated entrepreneurship accelerator programs(Journal of Business and Technical Communication, 2022) Spinuzzi, Clay; Cochran, Robert; Pogue, Gregory P.Accelerators support fledgling ventures with a set curriculum, moving them through a cycle of venture development, culminating in a Demo Day pitch in which the ventures argue for their viability. Yet firms are often involved in multiple programs with conflicting objectives and cycles. No research has addressed such conflicts. In this article, we examine an accelerator program partially linked to others to share resources. Drawing on the OODA framework, we identify disjunctures among cycles, anchoring this analysis at the final pitch. Working back from this Decide point, we examine interference among the associated programs.Item Linked but Desynched: An OODA Analysis of Associated Entrepreneurship Accelerator Programs(Sage, 2023) Spinuzzi, Clay; Cochran, Robert; Pogue, Gregory P.Accelerators are programs that support fledgling ventures with a set curric- ulum, moving them through a cycle of venture development that culmi- nates in a Demo Day pitch in which the ventures argue for their viability. Yet firms are often involved in multiple programs with conflicting objectives and cycles. No research has addressed such conflicts. This article examines an accelerator program that is partially linked to others in order to share resources. Drawing on the OODA (observe, orient, decide, act) framework, the authors identify disjunctures between cycles, anchoring this analysis at the final pitch. Working back from this deciding point, they examine interference between the associated programs.Item Parametric Approach to Linear Induction Accelerator Design(IEEE, 1991-01) Bresie, D. A.; Andrews, J. A.; Ingram, M. W.A parametric approach to defining effective accelerator designs is described. This method uses a computer optimization routine to iteratively seek out effective designs. The optimization routine is forced to search within a parameter space restricted to interesting and realistic parameters such as size, weight, voltage, and temperature rises. A filament model is used as the filter for the optimizer. Several linear induction accelerators have been designed using this method. The designed accelerators all used a switched capacitor power supply. While the run time of this code is moderately long, the resulting designs have good predicted performance. With realistic power supplies and materials, accelerator efficiencies in the 20 and 40% range were obtained. The effect of armature diameter, length-to-diameter ratio, and weight (as well as other parameters) on the optimum accelerator designed are describedItem Value creation in start-up discourse: linking pitch and venture through logics of justification(International Journal of Business Communication, 2023-01) Varas, Germán; Sabaj, Omar; Spinuzzi, Clay; Fuentes, Miguel; Gerard, Valentin; Cabezas, PaulaHow do start-ups create value through the language of their business pitches? In this article, we investigate that question by identifying the logics of justification they use, traditionally conceptualised as orders of worth. In this study of short written pitches in a six-month Chilean accelerator program, we describe how we detected logics of justification through pitch language, and we identify (a) co-occurrence patterns among logics of justification, (b) associations between logics of justification and industry sectors, and (c) associations between logics and a firm's customer segment (B2B, B2C). This study provides unique insights into how start-ups sometimes justify innovations by using specific patterns of language depending on a venture's features.