Types Of Launchers Research Articles

A Leaky-Wave Analysis of Resonant Bessel-Beam Launchers: Design Criteria, Practical Examples, and Potential Applicationsat Microwave and Millimeter-Wave Frequencies.

Resonant Bessel-beam launchers are low-cost, planar, miniaturized devices capable of focusing electromagnetic radiation in a very efficient way in various frequency ranges, with recent increasing interest for microwave and millimeter-wave applications (i.e., 3-300 GHz). In recent years, various kinds of launchers have appeared, with different feeding mechanisms (e.g., coaxial probes, resonant slots, or loop antennas), field polarization (radial, azimuthal, and longitudinal), and manufacturing technology (axicon lenses, radial waveguides, or diffraction gratings). In this paper, we review the various features of these launchers both from a general electromagnetic background and a more specific leaky-wave interpretation. The latter allows for deriving a useful set of design rules that we here show to be applicable to any type of launcher, regardless its specific realization. Practical examples are discussed, showing a typical application of the proposed design workflow, along with a possible use of the launchers in a modern context, such as that of wireless power transfer at 90 GHz.

Optimized Launch of a Rocket Launcher Type, From La Guajira - Colombia

The initial process for introducing the respective input variables to the mathematical models depends on the flight mission to define; keeping in mind the simplifications that are taking place are also established; as well as input data relevant to mention such as for example are the speed, the height, the cut-off, data concerning the orbit perigee, apogee, period and flat trajectory of the orbit. It is defined in the same simplified manner, the orbital elements and the inclination to consider. Additionally, the energy requirement is established and a specific impulse not defined, specific current pulses propellants either solid or liquid. Specific impulses of current propellants either solid or liquid must not exceed the limits established in technologically optimum mass distribution and the number of stages. At that point the main problem to observe will be associated with the number one phase in which we must find the path from the launch point to the injection of the payload, minimizing the loss of thrust required for acceleration, gravitational effects and drag. This requires a path to minimize these losses and minimize the overall fuel consumption of the vehicle. as part of the origin of the proposed research problem, was noted the work developed in the research hotbed SE-AST (Hotbed of astronautically studies) that have been developed academic work order relating to conceptual designs rocket dimensioning of motors and calculating orbits within the projects undertaken there labor and courses, but has been developed from work pending that address the dynamic of powered flight path.

Progress in the ITER electron cyclotron heating and current drive system design

An electron cyclotron system is one of the four auxiliary plasma heating systems to be installed on the ITER tokamak. The ITER EC system consists of 24 gyrotrons with associated 12 high voltage power supplies, a set of evacuated transmission lines and two types of launchers. The whole system is designed to inject 20MW of microwave power at 170GHz into the plasma. The primary functions of the system include plasma start-up, central heating and current drive, and magneto-hydrodynamic instabilities control. The design takes present day technology and extends towards high power CW operation, which represents a large step forward as compared to the present state of the art. The ITER EC system will be a stepping stone to future EC systems for DEMO and beyond.The EC system is faced with significant challenges, which not only includes an advanced microwave system for plasma heating and current drive applications but also has to comply with stringent requirements associated with nuclear safety as ITER became the first fusion device licensed as basic nuclear installations as of 9 November 2012.Since conceptual design of the EC system established in 2007, the EC system has progressed to a preliminary design stage in 2012, and is now moving forward towards a final design. The majority of the subsystems have completed the detailed design and now advancing towards the final design completion.

Development of a large-area planar surface-wave plasma source with a cavity launcher driven by a 915 MHz UHF wave

A large-area planar surface-wave plasma (SWP) source driven by a 915 MHz ultrahigh frequency (UHF) wave was developed. To avoid using large, thick dielectric plates as vacuum windows, we propose a cavity launcher consisting of a cylindrical cavity with several small quartz discs at the bottom. Three types of launchers with quartz discs located at different positions were tested to compare their plasma production efficiencies and spatial distributions of electron density. With the optimum launcher, large-area plasma discharges with a radial uniformity within ±10% were obtained in a radius of about 25–30 cm in Ar gas at 8 Pa for incident power in the range 0.5–2.5 kW. The maximum electron density and temperature were approximately (0.95–1.1) × 1011 cm−3 and 1.9–2.0 eV, respectively, as measured by a Langmuir probe located 24 cm below the bottom of the cavity launcher. Using an Ar/NH3 SWP with the optimum launcher, we demonstrated large-area amino-group surface modification of polyurethane sheets. Experimental results indicated that a uniform amino-group modification was achieved over a radius of approximately 40 cm, which is slightly larger than the radial uniformity of the electron density distribution.

Beam current enhancement of microwave plasma ion source utilizing double-port rectangular cavity resonator

Microwave plasma ion source with rectangular cavity resonator has been examined to improve ion beam current by changing wave launcher type from single-port to double-port. The cavity resonators with double-port and single-port wave launchers are designed to get resonance effect at TE-103 mode and TE-102 mode, respectively. In order to confirm that the cavities are acting as resonator, the microwave power for breakdown is measured and compared with the E-field strength estimated from the HFSS (High Frequency Structure Simulator) simulation. Langmuir probe measurements show that double-port cavity enhances central density of plasma ion source by modifying non-uniform plasma density profile of the single-port cavity. Correspondingly, beam current from the plasma ion source utilizing the double-port resonator is measured to be higher than that utilizing single-port resonator. Moreover, the enhancement in plasma density and ion beam current utilizing the double-port resonator is more pronounced as higher microwave power applied to the plasma ion source. Therefore, the rectangular cavity resonator utilizing the double-port is expected to enhance the performance of plasma ion source in terms of ion beam extraction.

Comparison of Electromagnetic and Conventional Launchers Based on Mauser 30-mm MK 30-2 Barrels

Electromagnetic railguns are similar to conventional guns in that both provide an accelerative force to the projectile while containing the loads on the bore. Each is subjected to extreme thermal and erosive environments. However, there are also fundamental differences due to the propulsion mechanisms. This paper compares these two types of launchers with emphasis on structural and material aspects.

A Novel Magnetic-Levitation System: Design, Implementation, and Nonlinear Control

This paper concerns the design, implementation, and nonlinear velocity-tracking control of a novel magnetic-levitation (maglev) system for magnetically levitated trains. The proposed system uses only one tubular linear induction motor to produce three forces required in a maglev system: propulsion, levitation, and guidance. Classical maglev systems, on the other hand, contain a separate force-generating system to build each of these three forces. Another benefit that the proposed system offers is that there is no need to control the guidance, and particularly, the levitation forces, one of the most challenging tasks in maglev systems. The system always centers the moving part during operation and eliminates the necessity for control of the levitation and guidance forces. However, the propulsion force strongly requires some control efforts because a linear induction motor has nonlinear system dynamics. This paper gives a condensed design guideline based on the mature theory of electromagnetic launchers, particularly the linear induction launcher type. It explains the implementation process, shows experimental test results, and finally, presents a nonlinear partial state-feedback controller for the proposed system.

Status of next generation expendable launchers concepts within the FLPP program

In the framework of the preparation of the next generation of launchers to be developed in Europe, the European Space Agency (ESA) has contracted NGL Prime and its industrial team to conduct a first slice of launch system and stage design activities and programmatic analyses for two types of launchers: • A new expendable mid-term launch system relying on elements or “Building Blocks” from Ariane and Vega to be operational by 2015. • A new long-term launch system called the Next Generation Launcher (NGL) to be operational by 2020–2025. The design reference missions include a 5 metric tons performance requirement into a Geostationary Transfer Orbit (GTO), to meet the European institutional need, with the increased capability to 8 metric tons into GTO by the addition of solid boosters, to meet the commercial market needs. In a first step, a series of trade-offs were conducted to select the concepts that best fit the requirements of the NGL and “Building Block” launcher options, in terms of propulsion (thrust level, engine characteristics), propellant choice (hydrogen, methane or solid propellants), launcher architecture (with or without strap-on boosters, bi or three stages architecture). In a second step, more detailed analyses were carried out in term of thermo-mechanical design, functional architecture, as well as in term of versatility capacity, i.e. the capability of the launcher to perform different missions than the reference ones. Consistently with this technical activity, a programmatic evaluation was consolidated by the industrial team. This paper details the outcomes of the activity carried out during this second step targeting at selecting one or two concepts. The paper will also give an overview and first results of the follow-on contract in which selected NGL concepts are being further investigated, in the prospect of creating a new European launcher family encompassing versions dedicated to the institutional needs and the commercial market (reference missions), as well as some versions dedicated to more demanding institutional missions (heavy low orbit payload insertions or escape missions) based on a Common Core Booster approach.

Critical interface issues associated with the ITER EC system

The ITER ECH system is an in-kind procurement consisting of four different types of gyrotrons (from EU, IN, JA and RF), transmission lines (from US) and two types of launchers (from EU and JA). Each subsystem must interface not only with the other but also with the auxiliary systems control and data acquisition computer and with the plasma (in the case of the launchers). The definition and management of interfaces is therefore essential for the system to guarantee performance, availability and reliability. The proper description of each interface boundary is essential for assembly and operation of the entire system as a single unit. In addition, progress has been made in the development of high power, long pulse systems and associated components that have not been integrated into the ITER EC design since the present ITER EC system was essentially specified prior to 2000. The ultimate physics performance and operational reliability in some situations is limited by this old design, which has not taken advantage of the knowledge and experience gained in operating the multi-megawatt ECH systems on present tokamaks and stellarators.The objective of this paper is to review the present ITER ECH system, which includes the power supplies, gyrotrons, transmission lines and launchers. Modifications are proposed which are performance driven and are engineered for reliability and maintainability, whilst reducing complexity and cost. Potential operating scenarios are discussed which require an intelligent and automatic decision making process, for example, directing the EC power to either of the two EC launchers, based on the immediate physics requirements. The interfaces between the subsystems are described and when possible improvements to each interface are proposed.

A fast switch, combiner and narrow-band filter for high-power millimetre wave beams

A fast directional switch (FADIS) is described, which allows controlled switching of high-power microwaves between two outputs. A possible application could be synchronous stabilization of neoclassical tearing modes (NTMs). Generally, the device can be used to share the installed EC power between different types of launchers or different applications (e.g. in ITER, midplane/upper launcher). The switching is performed electronically without moving parts by a small frequency-shift keying of the gyrotron (some tens of megahertz), and a narrow-band diplexer. The device can be operated as a beam combiner also, which offers attractive transmission perspectives in multi-megawatt ECRH systems. In addition, these diplexers are useful for plasma diagnostic systems employing high-power sources due to their filter characteristics.The principle and the design of a four-port quasi-optical resonator diplexer is presented. Low-power measurements of switching contrast, mode purity and efficiency show good agreement with theory. Preliminary frequency modulation characteristics of gyrotrons are shown, and first results from high-power switching experiments using the ECRH system for W7-X are presented.

Development and Evaluation of a TSLGG— Application of an ETC Gun System to its First Stage

A new type of launcher, ETC-TSLGG, is a two-stage light gas gun (TSLGG) using the technology of electrothermal-chemical (ETC) gun for its first stage. ETC-TSLGG is an improved version of the ETC gun which we had researched previously. It is developed to speed up the projectile velocity and control of variation of delay time from the ignition signal to the projectile launch. It will be used as a projectile launcher in a counter impact. Therefore, launch timing of the projectile is very important. Adjusting charge voltage and inductance of coils in a 10-kJ condenser bank so that variation of delay time is as small as possible, we depressed jitter of launch timing within a microsecond order in ETC-TSLGG. In this study, we investigated the delay time generation process. In order to clarify the operational state, pressure sensors were mounted in the ignition chamber and the pump tube. We measured projectile velocity, delay time, discharge voltage profile, current profile, and pressure profiles at different charge voltage and inductance. It can be said from these profiles that the delay time jitter was stabilized at high charge voltage and low inductance. Moreover, we have demonstrated that the delay time jitter of ETC-TSLGG was 1/100 smaller than that of the conventional TSLGG

Application of melt-textured YBCO to electromagnetic launchers

Melt-textured YBCO superconductors are capable of carrying higher current densities thancomparable copper conductors, and can therefore be used in electromechanical devicesrequiring high power densities. The advantage of textured YBCO superconductors is mostpronounced in large systems such as electromagnetic launchers for aircraft carriers. Ingeneral, an electromagnetic launcher consists of a series of stationary pulsed electromagnets(the primary), which attract and/or repel a carriage carrying one or more magnets (thesecondary). Several possibilities exist for the incorporation of HTSs into EM launchers,with the most direct being upgrading the magnets in the secondary to melt-texturedYBCO. A system was developed to study propulsive force in a coaxial-type launcher.Results from this study are presented and their implications for launcher developmentdiscussed. A second type of launcher was also studied, with a power supply integrated intothe launcher primary, so that the primary serves as a superconducting magnetic energystorage system. A method of optimizing energy conversion in a system of this type hasbeen found. The time dependence of the magnetic field in this type of launcher ispresented.

Radical-Enhanced Atomic Layer Deposition of Metallic Copper Thin Films

Radical-enhanced atomic layer deposition (REALD) of metallic copper films from copper(II)acetylacetonate and hydrogen radicals was studied. For this work, a new kind of REALD reactor was developed by adding a surface-wave launcher type of microwave plasma source to an inert gas-valved flow-type ALD reactor. The copper films, grown at 140°C, were polycrystalline, exhibited low resistivity, 15 μΩ cm for a 25 nm thick film, and had relatively low impurity levels. The films had excellent adhesion, and they grew conformally. The successful incorporation of the radical source to the ALD reactor encourages the study of other challenging ALD processes. © 2004 The Electrochemical Society. All rights reserved.

Spectrum broadening and fluctuations of lower hybrid waves observed in the CASTOR tokamak

Strong fluctuations of lower hybrid waves (LHW) amplitudes inside the plasma have been observed in experiments with different types of launchers. The fluctuation frequency is much higher than the frequency of plasma density fluctuations. This effect is explained by the presence of plasma fluctuations along the whole ray path. LHW spectrum broadening has been found by means of a double radiofrequency probe. This experimental result supports the assumption of spectral gap filling between the electron velocity distribution function and the spectrum launched into the plasma.

A demonstrator for the SSTO launcher with combined cycle propulsion

Restricted accessMoreSectionsView PDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmail Cite this article Czysz Paul A. 1999A demonstrator for the SSTO launcher with combined cycle propulsionPhil. Trans. R. Soc. A.3572285–2316http://doi.org/10.1098/rsta.1999.0432SectionRestricted accessA demonstrator for the SSTO launcher with combined cycle propulsion Paul A. Czysz Paul A. Czysz Department of Aerospace and Mechanical Engineering, Parks College of Engineering and Aviation, Saint Louis University, St Louis, MO 63103, USA Google Scholar Find this author on PubMed Search for more papers by this author Paul A. Czysz Paul A. Czysz Department of Aerospace and Mechanical Engineering, Parks College of Engineering and Aviation, Saint Louis University, St Louis, MO 63103, USA Google Scholar Find this author on PubMed Search for more papers by this author Published:01 August 1999https://doi.org/10.1098/rsta.1999.0432AbstractSpace launch systems of the 20th century are still regarded as both costly and unsafe. They have never acquired the reliability of commercial aircraft and they cannot abort from lift–off to mid–mission without massive losses. Most types of launchers are sacrificed after launch, and both hardware and environmental costs are significant. The cost of the launcher itself dominates this operation as it is the first, last and only time it flies. The user pays for the entire vehicle. For commercial aircraft operations, the frequency of flight and the lifespan of the aircraft means that the individual passenger pays about 6 for the cost of the aircraft per flight and the remainder is for fuel and operations. For commercial space launch to become both routine and economic, the need is to achieve the reliability, the sustained operation over a long lifespan, and the easy refurbishment of commercial aircraft. In seeking this solution, design studies have accepted that the ballistic missile launch may give way to either vertical or horizontal take–off aircraft using airbreathing propulsion up to a high flight Mach number and rockets thereafter. This paper examines the factors that shape the choice of airbreathing engines and airframe characteristics for SSTO space launchers, transatmospheric vehicles, boost–glide intercontinental range vehicles, and an associated demonstrator vehicle. Previous ArticleNext Article VIEW FULL TEXT DOWNLOAD PDF FiguresRelatedReferencesDetailsCited by Verstraete D, Bizzarri D and Hendrick P (2014) Demonstration of Compact Air Separation Technology for In-Flight Oxygen Collection Space Launchers, Journal of Propulsion and Power, 10.2514/1.B34958, 30:1, (62-69), Online publication date: 1-Jan-2014. Czysz P, Bruno C and Kato K (2001) Interactions between propulsion systems and the configuration concepts defines the design space 10th AIAA/NAL-NASDA-ISAS International Space Planes and Hypersonic Systems and Technologies Conference, 10.2514/6.2001-1924, , Online publication date: 24-Apr-2001. This Issue01 August 1999Volume 357Issue 1759Theme Issue ‘Hypersonic aircraft: lifting re–entry and launch’ compiled by L. H. Townend Article InformationDOI:https://doi.org/10.1098/rsta.1999.0432Published by:Royal SocietyPrint ISSN:1364-503XOnline ISSN:1471-2962History: Published online01/08/1999Published in print01/08/1999 License: Citations and impact Keywordsairbreathing propulsioncombined cycle propulsionavailable energy analysisspace launcherconfiguration geometrydemonstration aircraft

Pulsed discharges produced by surface waves

This paper presents a description of several efficient and easy-to-operate launchers intended for the pulsed regime. Two novel types of launchers which allow the use of high microwave power and high wave frequency are suggested. Using one of this launcher for the first time, high power SWs were excited in the 8-mm wavelength band. The paper also reviews the mechanisms of advance of the ionization front along the plasma column.

A rectangular large ECR plasma source

Large-area ECR processing plasmas have been developed. Magnetic fields are composed of permanent magnets located along closed lines, inverting the polarity line by line. At first a new type of microwave launching system which consists of a dielectric plate and metal bars was tested, by using a discharge chamber of circular geometry in a diameter of 30 cm. It was verified that the launcher was useful in the production of a large-area plasma in a wide range of gas pressures. By using this type of launcher, a plasma in a rectangular geometry with dimensions of 40 × 50 cm was generated. Basic data which lead to the solution used to obtain a large rectangular uniform plasma (uniformity better than ±5%) were obtained.

Pulsed discharges produced by high-power surface waves

The mechanisms of the ionization front advance in surface-wave-produced discharges are investigated using two experimental set-ups. The high-power surface waves are excited in a 3 cm wavelength band by a surfaguide and a novel type of launcher (an E-plane junction). The ionization front velocity of the surface wave is measured for a wide range of gas pressures, incident microwave power and initial pre-ionization. The experimental results are compared with theoretical ones based on three different models. The comparison between theory and experiment allows one to suggest a new interpretation of the ionization front's advance. The ionization front velocity is determined by a breakdown wave or an ionization wave in the electric field of a high-power surface wave in the zone near the ionization front.

Detonability limits of methane‐oxygen mixtures at elevated initial pressures

AbstractStudies and researches are conducted at ISL on the aero‐thermochemical launcher based on the RAM effect and entitled RAMAC. This type of launcher involves reactive gas mixtures which are chosen, in the thermally choked subsonic combustion mode, for their nondetonative properties. This paper gives the description of a new experimental facility at ISL, which involves a 90‐mm caliber detonation tube to carry out studies on reactive mixtures at initial pressures up to 5 MPa. First results for methane‐oxygen mixtures at 2.5 MPa and ambient temperature are given. Accordingly the upper detonability limits for these mixtures have been experimentally determined in 90 mm caliber. The experimental detonation velocities are compared with calculations by the Quartet thermochemical code.

New Microwave Launcher for Producing ECR Plasmas without Window Contamination I. Excitation of Electron Cyclotron Wave

A new microwave launcher with a reflector plate is experimentally examined. The reflector plate covers the microwave window and prevents particles from depositing onto the window surface. Two types of launchers are tested in terms of achieved density, excited wave mode and microwave reflection. It is found that the Type-II launcher is capable of exciting an electron cyclotron wave and produces dense plasmas of 1012 cm-3 density.