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Articles 1501 - 1530 of 1761

Full-Text Articles in Mechanical Engineering

Effect Of Firing Temperature And Holding Time On Characterization Of Al/Sic Metal Matrix Composites Produced By Pressureless Infiltration., Anne Zulfia, Myrna Ariati Apr 2006

Effect Of Firing Temperature And Holding Time On Characterization Of Al/Sic Metal Matrix Composites Produced By Pressureless Infiltration., Anne Zulfia, Myrna Ariati

Makara Journal of Technology

Effect of Firing Temperature and Holding Time on Characterization of Al/SiC Metal Matrix Composites Produced by Pressureless Infiltration. The production of Al-SiC metal matrix composite can be carried out by pressureless metal infiltration processs (PRIMEX). The experiment was conducted using aluminium AC2B ingot as a matrix and 50%Vf SiC powder as a reinforcement which is mixed with 10% Mg powder for wetting agent. The variables of this experiment are holding time and firing temperature to investigate the effect of these conditions on mechanical properties of Al-SiC metal matrix composites. Holding time was conducted for 2,5,8,10,12 hours and firing temperatures was …


Modification Of Bonding Strength Test Of Wc Hvof Thermal Spray Coating On Rocket Nozzle, Bondan T. Sofyan, Haposan J. Pardede, Marizki Stefano, Edi Sofyan Apr 2006

Modification Of Bonding Strength Test Of Wc Hvof Thermal Spray Coating On Rocket Nozzle, Bondan T. Sofyan, Haposan J. Pardede, Marizki Stefano, Edi Sofyan

Makara Journal of Technology

Modification of Bonding Strength Test of WC HVOF Thermal Spray Coating on Rocket Nozzle. One way to reduce structural weight of RX-100 rocket is by modifying the nozzle material and processing. Nozzle is the main target in weight reduction due to the fact that it contributes 30 % to the total weight of the structur. An alternative for this is by substitution of massive graphite, which is currently used as thermal protector in the nozzle, with thin layer of HVOF (High Velocity Oxy-Fuel) thermal spray layer. This paper presents the characterization of nozzle base material as well as the modification …


Development Of Fiber-Optic Humidity Sensor Probe With Gelatin Cladding, Akhiruddin Maddu, Kun Modjahidin, Sar Sardy, Hamdani Zain Apr 2006

Development Of Fiber-Optic Humidity Sensor Probe With Gelatin Cladding, Akhiruddin Maddu, Kun Modjahidin, Sar Sardy, Hamdani Zain

Makara Journal of Technology

Development of Fiber-Optic Humidity Sensor Probe with Gelatin Cladding. Humidity sensor based on optical fiber with gelatin cladding has been developed. In this humidity sensor probe, the origin cladding of optical fiber is replaced by gelatin coating as humidity sensitive cladding. Testing of the optical fiber sensor probe was conducted by measuring of light intensity transmitted on the optical fiber probe for each variation of different humidity treatments. Response of the optical fiber sensor probe measured from 42%RH to 99%RH, the results show an optical transmission curve varied with relative humidity (RH). Optical transmission in the optical fiber probe increase …


On The Performance Of Imt-2000 Communication Link Based On Stratospheric Platforms, Iskandar Iskandar, Shigeru Shimamoto Apr 2006

On The Performance Of Imt-2000 Communication Link Based On Stratospheric Platforms, Iskandar Iskandar, Shigeru Shimamoto

Makara Journal of Technology

A new means for providing wireless communication has been currently proposed. It is based on aerial vehicle known as High Altitude Platform or Stratospheric Platforms (SPF). The SPF will be operated at an altitude of 17-22 km above the ground. Therefore, the channel condition may be different compared with those of the conventional terrestrial or satellite wireless channel. In this paper, the channel propagation characteristic of such a system is firstly investigated by means of ray tracing algorithm. We emphasize our investigation in a typical urban environment, in which the mobile users mostly exist. We developed building block model for …


Analysis Of Technical Energy Losses By Using Simulation, Betrianis Betrianis, Randite Herawan Apr 2006

Analysis Of Technical Energy Losses By Using Simulation, Betrianis Betrianis, Randite Herawan

Makara Journal of Technology

Model is a representation of a system. Through model, it can be easier to forecast and control the changing of each element system. Electricity distribution is also a system. Losses are general problem that exist in a distribution network system. But with the right methods, specifically technical energy losses can be reduced in order to increase the efficiency. By making model of the distribution network, the value of technical energy losses in the whole network as well as in every line can be observed. Simulation can also be used to see all losses reduction alternatives. By comparing results from each …


Modeling Of Coupled-Tank System Using Fuzzy Takagi-Sugeno Model, Aries Subiantoro Apr 2006

Modeling Of Coupled-Tank System Using Fuzzy Takagi-Sugeno Model, Aries Subiantoro

Makara Journal of Technology

Modeling of Coupled-Tank System Using Fuzzy Takagi-Sugeno Model. This paper describes modeling of coupledtank system based on data measurement using fuzzy Takagi-Sugeno model. The fuzzy clustering method of Gustafson- Kessel algorithm is used to classify input-output data into several clusters based on distance similarity of a member of input-output data from center of cluster. The formed clusters are projected orthonormally into each linguistic variables of premise part to determine membership function of fuzzy Takagi-Sugeno model. By estimating data in each cluster, the consequent parameters of fuzzy Takagi-Sugeno model are calculated using weighted least-squares method. The resulted fuzzy Takagi-Sugeno model is …


Design Of Induction Motor Drive Without Velocity Sensor Using Current Vector Controller With Full And Reduced Observer Moving To Dq Axis, Ridwan Gunawan, Feri Yusivar, Wahidin Wahab, Zuhal A. Kadir Apr 2006

Design Of Induction Motor Drive Without Velocity Sensor Using Current Vector Controller With Full And Reduced Observer Moving To Dq Axis, Ridwan Gunawan, Feri Yusivar, Wahidin Wahab, Zuhal A. Kadir

Makara Journal of Technology

Design of Induction Motor Drive Without Velocity Sensor Using Current Vector Controller with Full and Reduced Observer Moving to DQ Axis. The observer is used in estimation velocity sensor usually in α-β axis, therefore this situation will need an extra transformation when we want to add compensator because the flux model is in direct and quadrature-axis dq. Every used the transformation to make possible emerge an error. So in this simulation is used a method to estimate the velocity of induction motor drive with observer that is moved to dq-axis. The model of actual motor used is in alfa-beta axis, …


Hybrid Identification System With Arx And Fast Fourier Transform In Application Of A Quarter Of Vehicle Half Active Suspension, Noveri Lysbetti M, Antonius R. Apr 2006

Hybrid Identification System With Arx And Fast Fourier Transform In Application Of A Quarter Of Vehicle Half Active Suspension, Noveri Lysbetti M, Antonius R.

Makara Journal of Technology

Hybrid Identification System with ARX and Fast Fourier Transform in Application of a Quarter of Vehicle Half Active Suspension. In a control system problem, identification system mechanism is a absolute thing, especially in adaptation controlling to disturbance changing. For that case, is needed an identification method which can identify the changing of disturbance in that system. The aim of this research is to give an alternative in system/plant identification which is a combination (hybrid) of ARX and Fast Fourier Transform. So, it is needed an algorithm design for identification process. In this case, the designed algorithm will be implemented in …


Neural Network-Based Output Feedback Controller For Lean Operation Of Spark Ignition Engines, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier, Jonathan B. Vance, Pingan He Jan 2006

Neural Network-Based Output Feedback Controller For Lean Operation Of Spark Ignition Engines, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier, Jonathan B. Vance, Pingan He

Electrical and Computer Engineering Faculty Research & Creative Works

Spark ignition (SI) engines running at very lean conditions demonstrate significant nonlinear behavior by exhibiting cycle-to-cycle dispersion of heat release even though such operation can significantly reduce NOx emissions and improve fuel efficiency by as much as 5-10%. A suite of neural network (NN) controller without and with reinforcement learning employing output feedback has shown ability to reduce the nonlinear cyclic dispersion observed under lean operating conditions. The neural network controllers consists of three NN: a) A NN observer to estimate the states of the engine such as total fuel and air; b) a second NN for generating virtual input; …


System Identification Of A Pasteurisation Process: A Comparison Of Direct And Indirect Methods, Niel Canty Jan 2006

System Identification Of A Pasteurisation Process: A Comparison Of Direct And Indirect Methods, Niel Canty

Theses

The primary focus of this research is to identify a linear model for a direct steam injection (DSI) pasteurisation process which is a component of a large-scale pilot evaporation process widely used in the dairy industry. The pasteurisation process has been identified as a key component of the evaporation process. The author believes that no previously published work has focused on identifying models for a DSI pasteurisation process which makes this work an original contribution to the area. The pasteurisation process can be modelled as a single-input, single-output (SISO) process with a measurable disturbance. Thus two transfer functions were required …


Reducing Energy Costs By Optimizing Controller Tuning, Aidan O'Dwyer Jan 2006

Reducing Energy Costs By Optimizing Controller Tuning, Aidan O'Dwyer

Conference papers

The proportional integral derivative (PID) controller is the most dominant form of automatic controller in industrial use today. With this technique, it is necessary to adjust the controller parameters according to the nature of the process. This tailoring of controller to process is known as controller tuning. Controller tuning is easily and effectively performed using tuning rules (i.e. formulae for controller tuning, based on process information). Such tuning rules allow the easy set up of controllers to achieve optimum performance at commissioning. Importantly, they allow ease of re-commissioning if the characteristics of the process change. The paper outlines the results …


Robustness And Control Of A Magnetically Levitated Transportation System, Grzegorz Oleszczuk Jan 2006

Robustness And Control Of A Magnetically Levitated Transportation System, Grzegorz Oleszczuk

Mechanical & Aerospace Engineering Theses & Dissertations

Electromagnetic suspension of Magnetic Levitation Vehicles (Maglev) has been studied for many years as an alternative to wheel-on rail transportation systems. In this work, design and implementation of control systems for a Maglev laboratory experiment and a Maglev vehicle under development at Old Dominion University are described. Both plants are modeled and simulated with consideration of issues associated with system non-linearity, structural flexibility and electromagnetic force modeling. Discussion concerning different control strategies, namely centralized and decentralized approaches are compared and contrasted in this work. Different types of electromagnetic non-linearities are considered and described to establish a convenient method for modeling …


Using Rfid Technology In Collaborative Design Of The Assembly Systems, Stevan Stankovski, Gordana Ostojić, Vukica Jovanović, Branislav Stevanov Jan 2006

Using Rfid Technology In Collaborative Design Of The Assembly Systems, Stevan Stankovski, Gordana Ostojić, Vukica Jovanović, Branislav Stevanov

Engineering Technology Faculty Publications

Modern production conditions require the application of the concept of distributing production. This approach means coordinative production in a number of small and middle size companies. Multiplex products, consisting of a number of parts, components, and modules are assembled in one function unit in one company, but they may not be manufactured in one place. Huge factory and production complex, which existed in our country, comprised all phases of product lifecycle, from the development of a concept solution to the assembly. Technology of product manufacturing, resource logistics, quality control, product testing and verification of product function characteristics all represented activities …


Rfid Technology Use In Assembly And Disassembly Processes, Gordana Ostojić, Milovan Lazarević, Vukica Jovanović, Stevan Stankovski, Ilija Ćosić Jan 2006

Rfid Technology Use In Assembly And Disassembly Processes, Gordana Ostojić, Milovan Lazarević, Vukica Jovanović, Stevan Stankovski, Ilija Ćosić

Engineering Technology Faculty Publications

Modern production conditions demand the application of the concept of distributed production. Today companies are specialized for partial technology processes. Hundreds, sometimes even thousands, of collaborative processes depend on workers’ interaction and communication in product assembly and disassembly phases. RFID technologies can be really helpful in identifying objects in terms of sustainable development, regarding disassembly, recycling and reuse. In this paper we presented VCDE system architecture and the realization method of RFID technology as well as the data acquisition using RFID technology during the product lifecycle from the design process, production, assembly, usage, and an special example is given regard- …


College Of Engineering Senior Design Competition Fall 2005, University Of Nevada, Las Vegas Dec 2005

College Of Engineering Senior Design Competition Fall 2005, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge.

The senior design competition helps to focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects …


Synthesis Of Fuel Cell Membrane: Copolymerization Of Styrene On Etfe Film By Grafted Pre-Irradiation, Yohan Yohan, Rifai M. Nur, Lilik Hendrajaya, E. S. Siradj Nov 2005

Synthesis Of Fuel Cell Membrane: Copolymerization Of Styrene On Etfe Film By Grafted Pre-Irradiation, Yohan Yohan, Rifai M. Nur, Lilik Hendrajaya, E. S. Siradj

Makara Journal of Technology

Synthesis of Fuel Cell Membrane: Copolymerization of Styrene on ETFE Film by Grafted pre-Irradiation. Preirradiation Grafting styrene monomer on ETFE film has been prepared. Research has been performed by γ-ray radiation at various total dose from 2.5 – 12.5 kGy and various dose rate from 1.3 – 1.9 kGy/hour. Irradiated copolymer is then grafted by styrene monomer in various solvent: ethanol, 2-propanol, and toluene, various concentration from 20 – 70% volume, various temperature from 50 – 90oC, and various grafting time from 2 – 12 hours. The results showed that percent of grafting is increase with increase of total dose …


Design Of Product Placement Layout In Retail Shop Using Market Basket Analysis, Isti Surjandari, Annury Citra Seruni Nov 2005

Design Of Product Placement Layout In Retail Shop Using Market Basket Analysis, Isti Surjandari, Annury Citra Seruni

Makara Journal of Technology

Retailing is an industry with high level of competition. It is a customer-based industry which depends on how it could be aware of what the customers’ needs and requirements are. One technique most used in supermarkets is the mix merchandise. The purpose of this paper is to identify associated products, which then grouped in mix merchandise with the use of market basket analysis. This association between products then will be applied in the design layout of the product in the supermarket. The process of identifying the related products bought together in one transaction is done by using data mining technique. …


Production Hydrogen And Nanocarbon Via Methane Decomposition Using Ni-Based Catalysts. Effect Of Acidity And Catalyst Diameter, Widodo W. Purwanto, M. Nasikin, E. Saputra, L. Song Nov 2005

Production Hydrogen And Nanocarbon Via Methane Decomposition Using Ni-Based Catalysts. Effect Of Acidity And Catalyst Diameter, Widodo W. Purwanto, M. Nasikin, E. Saputra, L. Song

Makara Journal of Technology

Objectives of this research are mainly to study impacts of acidity strength (by varying amount of precipitant and loading Al-Si) and the effect of nickel particle size (by varying calcinations temperature) on decomposition reaction performances. In this research, high-nickel-loaded catalyst is prepared with two methods. Ni-Cu/Al catalysts were prepared with co-precipitation method. While the Ni-Cu/Al-Si catalyst were prepared by combined co-precipitation and sol-gel method. The direct cracking of methane was performed in 8mm quartz fixed bed reactor at atmospheric pressure and 500-700°C. The main results showed that the Al content of catalyst increases with the increasing amount of precipitant. The …


Design And Implementation Of 1-2 Ghz Stepped Frequency Gpr For Buried Metal Detection, Joko Suryana, Andriyan B. Suksmono, Tati R. Mengko Nov 2005

Design And Implementation Of 1-2 Ghz Stepped Frequency Gpr For Buried Metal Detection, Joko Suryana, Andriyan B. Suksmono, Tati R. Mengko

Makara Journal of Technology

Design and Implementation of 1-2 GHz Stepped Frequency GPR for Buried Metal Detection. In this paper, we describe the design and realization steps of 1 – 2 GHz SFGPR (Stepped Frequency Ground Penetrating Radar) transceiver for metal detection under the ground. Before using prototyped GPR for detecting the metal under the ground, several of calibration processes must be performed, namely phase calibration and monocycle pulse waveform calibration. After completing the calibrations, this prototyped GPR would be ready for detecting a hidden object such as a metal plate 5 cm under the ground in our small test range size 25 cm …


Simultaneous Treatment Of Organic (Phenol) And Heavy Metal (Cr6+ Or Pt4+) Wastes Over Tio2, Zno-Tio2 And Cds-Tio2 Photocatalysts, Slamet Slamet, R. Arbianti, Daryanto Daryanto Nov 2005

Simultaneous Treatment Of Organic (Phenol) And Heavy Metal (Cr6+ Or Pt4+) Wastes Over Tio2, Zno-Tio2 And Cds-Tio2 Photocatalysts, Slamet Slamet, R. Arbianti, Daryanto Daryanto

Makara Journal of Technology

Simultaneous Treatment of Organic (Phenol) and Heavy Metal (Cr6+ or Pt4+) Wastes over TiO2, ZnO-TiO2 and CdS-TiO2 Photocatalysts. Treatment of heavy metal (Cr6+ and Pt4+) and organic (phenol) wastes has been studied using the relatively new method, i.e. simultaneous photocatalytic process over TiO2 photocatalysts in the batch photoreactor. Following the photocatalytic reduction of the heavy metal wastes, recovery of Cr and Pt was carried out by precipitation and leaching method, respectively. The experimental results show that in the simultaneous photocatalytic system, there is a synergism effect between the photocatalytic reduction of heavy metal waste (Cr6+ or Pt4+) and the oxidation …


Design Of Generating Dual Frequency Operation For Triangular Microstrip Antenna Using Electromagnetic Coupling, Indra Surjati, Eko Tjipto Rahardjo, Djoko Hartanto Nov 2005

Design Of Generating Dual Frequency Operation For Triangular Microstrip Antenna Using Electromagnetic Coupling, Indra Surjati, Eko Tjipto Rahardjo, Djoko Hartanto

Makara Journal of Technology

Design of Generating Dual Frequency Operation for Triangular Microstrip Antenna Using Electromagnetic Coupling. A new design is proposed in this paper by applying a pair of slits using a microstrip feed line. Therefore the microstrip line feeding system is electromagnetically coupled to the patch. The antenna works at two different frequencies in the range from 2 GHz to 4 GHz (S band frequency). The results of the simulation shows that the dual frequency operation can be created when the slit width is 1 mm and the height of the slits ranges from 10 mm to 14 mm with inter slit …


Development Of Low Frequency Vibration Method Of Direct-Write Deposition Relevant To Layer Manufacturing Application, Susilo Adi Widyanto, Alva Edy Tontowi, Jamasri Jamasri, Heru Santosa Budi Rochardjo Nov 2005

Development Of Low Frequency Vibration Method Of Direct-Write Deposition Relevant To Layer Manufacturing Application, Susilo Adi Widyanto, Alva Edy Tontowi, Jamasri Jamasri, Heru Santosa Budi Rochardjo

Makara Journal of Technology

The research of deposition process is the first step in development process of multi materials selective laser sintering. The deposition process enables to settle multi materials powder in horizontal formation on one layer. In this research we use low frequency (70 - 200Hz) to vibrate a hopper nozzle in which powder is settled. The research method consists of two steps, the first step is to determine flow-ability parameters and the second is to join flow ability parameter with other parameters such that the line width can be controlled. The results show that the line width depends on uniformity of particle …


2005 Fall Engr333 Project Assignment, Matthew K. Heun Sep 2005

2005 Fall Engr333 Project Assignment, Matthew K. Heun

ENGR 333

In the Fall 2005 semester, I challenged the ENGR333 students to “develop realistic designs for the wellness center HVAC system and upgraded physical plant infrastructure.”

Customer

The customer for this project was Calvin’s VP for finance Henry DeVries.


Protein Impregnated Polymer (Pip) Film Infrared Sensor Using Suspended Microelectromechanical Systems (Mems) Pixels, Tetsuo Kaieda Sep 2005

Protein Impregnated Polymer (Pip) Film Infrared Sensor Using Suspended Microelectromechanical Systems (Mems) Pixels, Tetsuo Kaieda

Theses and Dissertations

The Air Force Research Laboratory Materials and Manufacturing Directorate have developed a novel protein impregnated polymer (PIP) suspension that changes resistivity as a function of absorbed infrared radiation. Due to this property, the PIP is a potential material for use as an uncooled bolometer, or thermal sensor. In this research, a thermally-isolated pixel design, sensor characterization methods, and sensor fabrication and processing steps were developed. To create a microbolometer, the PIP was applied to two prototype micro-electro-mechanical systems (MEMS) surface micro-machined structures. The first is a raised cantilever pixel array that uses residual stress polysilicon and metal film arms to …


Static And Dynamic Obstacle Avoidance For Miniature Air Vehicles, Jeffery Brian Saunders, Brandon Call, Andrew Curtis, Randal W. Beard, Timothy W. Mclain Sep 2005

Static And Dynamic Obstacle Avoidance For Miniature Air Vehicles, Jeffery Brian Saunders, Brandon Call, Andrew Curtis, Randal W. Beard, Timothy W. Mclain

Faculty Publications

Small unmanned air vehicles are limited in sensor weight and power such that detection and avoidance of unknown obstacles during flight is difficult. This paper presents a low power low weight method of detection using a laser range finder. In addition, a rapidly-exploring random tree algorithm to generate waypoint paths around obstacles known a priori is presented, and a dynamic geometric algorithm to generate paths around detected obstacles is derived. The algorithms are demonstrated in simulation and in flight tests on a fixed-wing miniature air vehicle (MAV).


Adaptive Control Of A Projectile Fin Using Piezoelectric Elastic Beam, Smitha Mani, Sahjendra N. Singh, Surya Kiran Parimi, Woosoon Yim, Mohamed B. Trabia Aug 2005

Adaptive Control Of A Projectile Fin Using Piezoelectric Elastic Beam, Smitha Mani, Sahjendra N. Singh, Surya Kiran Parimi, Woosoon Yim, Mohamed B. Trabia

Mechanical Engineering Faculty Research

No abstract provided.


Knowledge Representation, Organization, And Formalization For Simulation Modeling Of Discrete Manufacturing System, Jung Hung Ma Aug 2005

Knowledge Representation, Organization, And Formalization For Simulation Modeling Of Discrete Manufacturing System, Jung Hung Ma

All-Inclusive List of Electronic Theses and Dissertations

Simulation is an useful tool that helps managers making decision by designing models for real systems. It helps companies to study behaviors of real systems hy analyzing computer models and improve the systems based on the experiments' results. However, cross-domain knowledge requirement and lack of tools facilitate modeling are the main reasons that make industries hesitate to use simulation to assist making decision. This research is an attempt to develop robust knowledge representations for discrete manufacturing system and conceptual simulation model. A modeling methodology was proposed to utilize these knowledge representations (KRs) for developing conceptual simulation models from application domain …


Modeling, Fabrication, And Optimization Of Niobium Cavities Final Phase: Final Report, Robert A. Schill Jr., Mohamed Trabia, William Culbreth Aug 2005

Modeling, Fabrication, And Optimization Of Niobium Cavities Final Phase: Final Report, Robert A. Schill Jr., Mohamed Trabia, William Culbreth

Transmutation Sciences Materials (TRP)

This final report provides the activities and accomplishments of Modeling, Fabrication, and Optimization of Niobium Cavities – Final Phase. The fluid flow experiments for the etching of the superconducting cavity walls and baffle designs of phase II of the three phases has been completed leading to a MS thesis in December of 2003. Designing the experimental setup of secondary electron emission was well underway in early summer of 2003 when funding was made available for this portion of the study. By March 2004, many of the components of the experimental study reached UNLV with some assembly accomplished. The first secondary …


Insulator Charging In Rf Mems Capacitive Switches, Jay F. Kucko Jun 2005

Insulator Charging In Rf Mems Capacitive Switches, Jay F. Kucko

Theses and Dissertations

While capacitive radio frequency microelectromechanical (RF MEM) switches are poised to provide a low cost, high isolation, low power alternative to current RF switch technologies, there are still reliability issues limiting switch lifetime. Previous research identified insulator charging as a primary cause of switch failure. Changes in switch pull-in and release voltages were measured to provide insight into the mechanisms responsible for charging and switch failure. A spatial and temporal dependent model was developed to describe silicon nitride's time-dependent charging as a function of applied bias. This model was verified by applying constant biases to metal-silicon nitride-silicon capacitors and tracking …


Modeling, Fabrication, And Optimization Of Niobium Cavities: Phase Iii Fourth Quarterly Report, Robert A. Schill Jr., Mohamed Trabia, William Culbreth Apr 2005

Modeling, Fabrication, And Optimization Of Niobium Cavities: Phase Iii Fourth Quarterly Report, Robert A. Schill Jr., Mohamed Trabia, William Culbreth

Transmutation Sciences Materials (TRP)

Niobium cavities are important parts of the integrated NC/SC high-power linacs. Over the years, researchers in several countries have tested various cavity shapes. They concluded that elliptically shaped cells are the most appropriate shape for niobium superconducting cavities. The surface preparation can significantly affect the secondary electron emission yields. Such yields are used in design codes. Current codes use values obtained from niobium samples cleaned by a different means at temperatures other than the operating temperature. Secondary electron emission studies on LANL surface-cleaned niobium are conducted with preliminary data presented in this report at room temperature. Soon studies will be …