A5100769202- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Magnetic confinement fusion research
- Nuclear Physics and Applications
- Particle Accelerators and Free-Electron Lasers
- Spacecraft and Cryogenic Technologies
- Plasma Diagnostics and Applications
- Nuclear reactor physics and engineering
- Engineering Applied Research
- Aluminum Alloy Microstructure Properties
- Gyrotron and Vacuum Electronics Research
- Metal Forming Simulation Techniques
- Spacecraft Design and Technology
- Metal and Thin Film Mechanics
- Physics of Superconductivity and Magnetism
- Aluminum Alloys Composites Properties
- Aerodynamics and Fluid Dynamics Research
- Electromagnetic Launch and Propulsion Technology
- Internet of Things and Social Network Interactions
- Fusion materials and technologies
- Air Traffic Management and Optimization
- Manufacturing Process and Optimization
- Advanced Aircraft Design and Technologies
- Traditional Chinese Medicine Studies
- Simulation and Modeling Applications
Thomas Jefferson National Accelerator Facility
2011-2024
Oak Ridge National Laboratory
2014-2024
China Spallation Neutron Source
2024
Spallation Neutron Source
2002-2024
Hanyang University
2019
Seoul National University
1999-2018
Korea University of Technology and Education
2018
Korea Automotive Technology Institute
2013
Pukyong National University
2011
Konkuk University
2008-2009
The Spallation Neutron Source project includes a superconducting linac section in the energy range from 186 MeV to 1000 MeV. For this two types of cavities are needed with geometrical /spl beta/ values beta/=0.61 and beta/=0.81. An aggressive cavity prototyping program is being pursued at Jefferson Lab, which calls for fabricating testing four beta/=0.81 cavities. Both consist six cells made high purity niobium feature one HOM coupler TESLA type on each beam pipe port power coaxial input...
The corrosion resistance of homogenized Al-Mg (6.5%) alloy—adding Si, Zn, Mn, and Fe (0.2%) to improve various properties—was observed. Differential scanning calorimetry (DSC) a JMatPro simulation revealed that the optimal homogenization temperature was 450 °C. carried out at °C for 3, 6, 12, 18, 24, 30 h in order view change. Corrosion analyzed by polarization test 3.5 wt % NaCl solution. improved with increasing time up 24 h, but there no change longer periods. To observe reason...
High pressure chemistry has traditionally involved applying and increasing temperature until conditions become thermodynamically favorable for phase transitions or reactions to occur. Here, high alone is used as a starting point carrying out rapid, self-propagating metathesis reactions. By initiating chemical under pressure, crystalline phases, such gallium nitride, can be synthesized which are inaccessible when initiated from ambient conditions. The single-phase nitride made by displays...
The Oak Ridge Spallation Neutron Source comprises a 1 GeV, 1.5 MW linear accelerator followed by an accumulator ring and liquid mercury target. To manage the beam loss caused ${H}^{0}$ excited states created during ${H}^{\ensuremath{-}}$ charge-exchange injection into ring, stripper foil is located inside one of chicane dipoles. This has some interesting consequences that were not fully appreciated until power reached about 840 kW. One consequence was sudden failure system due to convoy...
The Spallation Neutron Source (SNS) radio-frequency quadrupole (RFQ) had resonance control instabilities at duty factors higher than approximately 4%. Systematic investigations have been carried out to understand the cause of instability and ensure operational stability RFQ. most critical source is revealed be an interaction between hydrogen released by beam bombardments RFQ rf field resulting in a discharge, which consumes additional power could operate unstable region. This paper reports...
A 1 MVA single phase high temperature superconducting (HTS) transformer was fabricated and a part of experimental test for characteristics the performed. The rated voltages primary secondary HTS are 22.9 kV 6.6 respectively. BSCCO-2223 wire used windings whose shapes double pancake arranged reciprocally. Single 4 wires were considering current transformer. Four in transposed at connection between pancakes 3 times. electrical insulation transport performed 77 K using liquid nitrogen. rest is progress.
The baseline Spallation Neutron Source (SNS) accelerator will provide a 1-GeV, 1.4-MW proton beam to mercury target for the production of neutrons. main acceleration H-beam is provided by 81 superconducting cavities installed in 23 cryomodules operating at 805 MHz. design linac includes 2.1-K, 2.5-kW cryogenic plant maintain below helium lambda point efficient operation high accelerating gradients. In this paper conditions are analyzed rather than ones, which still guarantees gradient...
This paper presents the configuration design method for a parameter-based geometry representation and aircraft complex configurations generation using component-based approach. The algorithm is based on shape functions to keep modified smooth represent curve shapes with small number of control variables. can be especially effective efficient when changes in local are required. Controlling becomes also much easier because these represented non-dimensional space polynomials. Representation...
인공위성의 열제어는 인공위성이 운용궤도상에서 겪는 고진공, 극한의 온도변화 환경에서 위성 구성품의 온도변화를 허용한계 온도 범위 내에서 유지하는데 목적이 있다. 본 연구에서는 저궤도 관측위성(LEO)의 광학탑재체에 대한 열해석 과정으로 열진공 시험 조건, 챔버의 형상, 탑재체 내부의 열적 환경을 고려하여 모델을 구성하고 궤도 조건에 따른 열해석을 수행하였다. 또한 광학탑재체의 지상 수행하여 시험을 위한 시험조건을 정립하였다. The purpose of satellite thermal control design is to maintain all the elements a spacecraft system within their temperature limits for mission phases. analysis model Low Earth Orbit payload level simulation established by considering vacuum test...
Based on the Higher Order Mode (HOM) field properties, Spallation Neutron Source (SNS) HOM damping requirements have been determined by bunch tracking simulations. Transverse instabilities are found to be absent and transverse error magnifications acceptable if loaded cavity Q for each mode is less than 10/sup 8/ expected cavity-to-cavity frequency variation due manufacturing tolerances present. Longitudinal 8/, non-pi fundamental has value, Each of two types three longitudinal modes that...
The Superconducting Linac at SNS has been operating with beam for almost two years. As the first operational pulsed superconducting linac, many of aspects its performance were unknown and unpredictable. A lot experience gathered during commissioning components, turn on operation increasingly higher power. Some cryomodules have cold well over years extensively tested. consistently conducted 4.4 K 10 15 pulses per second, some tested 30 60 Hz tests performed 2 K. Careful balance between safe...
Recently, the performances of speed and accuracy are enhanced in machine tools. The high tools usually causes harmful thermal displacements on objects. To reduce displacements, generally adopt oil coolers with precise temperature control function. This study aims at outlet hot-gas bypass manner based PI logic. system was designed for obtaining steady state error within <TEX>${\pm}0.1^{\circ}C$</TEX> maximum overshoot 0.8% even though abrupt disturbances added to system. We showed that gains...
Elliptical SRF cavities operated in pulsed mode experience dynamic Lorentz detuning because of the time varying radiation pressure. Due to narrow electromagnetic bandwidth these resonators, induced can severely affect their matching conditions RF feeding system. The active compensation scheme using piezoelectric tuners has proven be a viable and attractive method minimize effects detuning. To optimize this compensation, mechanical parameters are extracted for action forces tuner from both...
A 2.0-in VGA TFT-LCD with the pixel density of 403 ppi has been developed using LTPS technology. It is possible to produce a compact module by embedding driving circuits in peripheral area. In addition, high brightness over 200cd/cm2 and wide viewing angles have achieved IPS mode p-type transistors. believed that this development fulfills various requirements for ubiquitous mobile devices.