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This paper constructed a new high speed and power density servo motor design scheme based on magnetic pole eccentricity proposed according to the requirements of electrical performance parameters. The analytical formulae were deduced in view of the theory of thick-walled elastic cylinders and the actual model by analytical calculations and finite element calculations. The structure strength of permanent magnet was analyzed. Furthermore, comprehensively comparing and analyzing the calculation results of the two methods verify the accuracy of the analytical calculation method and the rationality of the permanent magnet structure design. In brief, this paper provides a reference for the design of high-speed motor magnetic pole eccentricity.

The magnificent increase in the performance of integrated circuits is made possible by semiconductor Physics. Due to very large-scale integration, scaling has approached its fundamental limits, which is the biggest challenge for the semiconductor industry. Therefore, in the recent years researchers across the globe are focusing on emerging field of spintronics. In this thrust area of spintronics research, spin field effect transistor (s-FET) is an extensively studied device. In literature, researchers have studied and optimized two main types of spin field effect transistors namely Ballistic and Non-Ballistic spin-field effect transistors. This research paper has presented the recent developments in the field of Ballistic and Non-Ballistic spin-field effect transistors. This paper has briefly explained the approach to design, development and fabrication of s-FET by taking a case study. Firstly, the spin field effect transistor was proposed by Datta–Das, which has proved to be the milestone in the area of spintronic technology. Mainly, spin transistor is prepared using a ballistic semiconductor, sandwiched between ferromagnetic metallic source and drain contacts.The magnificent increase in the performance of integrated circuits is made possible by semiconductor Physics. Due to very large-scale integration, scaling has approached its fundamental limits, which is the biggest challenge for the semiconductor industry. Therefore, in the recent years researchers across the globe are focusing on emerging field of spintronics. In this thrust area of spintronics research, spin field effect transistor (s-FET) is an extensively studied device. In literature, researchers have studied and optimized two main types of spin field effect transistors namely Ballistic and Non-Ballistic spin-field effect transistors. This research paper has presented the recent developments in the field of Ballistic and Non-Ballistic spin-field effect transistors. This paper has briefly explained the approach to design, development and fabrication of s-FET by taking a case study. Firstly, the spin field effect transistor was proposed by Datta–Das, which has proved to be the milestone in the area of ...

In this paper, we present the theoretical study of double electromagnetically induced transparency (EIT) in a four-level V-type system which is formed by two co-propagating laser fields and the Zeeman sublevels of hyperfine transitions of 87Rb D2 line. The density matrix equations for the four-level V-type system are derived from the Liouville’s equation of motion and numerically solved under steady state condition to get the EIT signals. We consider both the probe and pump transmission spectra for the observation of double EIT signals under both Doppler free and Doppler broadened conditions. In case of Doppler free medium, two EIT peaks are formed in the two Lorentzian shape dips present in the both Doppler free probe and pump transmission spectra. When the medium becomes Doppler broadened, the two EIT peaks are formed in the probe transmission spectrum having Doppler broadened background, but the pump transmission spectrum gives two EIT peaks in the Doppler free background. The effect of probe intensity variation on the two EIT peaks is studied in case of Doppler broadened probe transmission spectrum. It is found that the heights of the EIT peaks decrease as the probe intensity increases, and interestingly one EIT peak converts into EIA (electromagnetically induced absorption) dip at some strong probe intensity value. The depth of the EIA dip is significantly increased as the intensity of the probe field increases. We also present the effect of probe intensity variation on the EIT peaks in the pump transmission spectrum and found that the EIT peak heights are increased as the probe intensity increases.In this paper, we present the theoretical study of double electromagnetically induced transparency (EIT) in a four-level V-type system which is formed by two co-propagating laser fields and the Zeeman sublevels of hyperfine transitions of 87Rb D2 line. The density matrix equations for the four-level V-type system are derived from the Liouville’s equation of motion and numerically solved under steady state condition to get the EIT signals. We consider both the probe and pump transmission spectra for the observation of double EIT signals under both Doppler free and Doppler broadened conditions. In case of Doppler free medium, two EIT peaks are formed in the two Lorentzian shape dips present in the both Doppler free probe and pump transmission spectra. When the medium becomes Doppler broadened, the two EIT peaks are formed in the probe transmission spectrum having Doppler broadened background, but the pump transmission spectrum gives two EIT peaks in the Doppler free background. The effect of probe intensity...

Spherical Tokamak (ST) path to Fusion has been proposed [1] and experiments on STs demonstrated feasibility of this approach. Advances in High Temperature Superconductor technology [2] allows significant increase in the toroidal field (TF) which was found to improve confinement in STs. The combination of the high normalised plasma pressure, β, which has been achieved in STs [3], and high TF that can be produced by HTS TF magnets, opens a path to lower-volume fusion reactors, in accordance with the fusion power scaling proportional to β2Bt4V. Modular approach then becomes an alternative to high power, GW-scale Fusion reactors [4,5]. Feasibility of low-power compact ST reactor module and physics and engineering challenges of the accelerated, ST path to Fusion Power are discussed in this paper, on example of the first our prototype on this route, high-field compact spherical tokamak ST40.Spherical Tokamak (ST) path to Fusion has been proposed [1] and experiments on STs demonstrated feasibility of this approach. Advances in High Temperature Superconductor technology [2] allows significant increase in the toroidal field (TF) which was found to improve confinement in STs. The combination of the high normalised plasma pressure, β, which has been achieved in STs [3], and high TF that can be produced by HTS TF magnets, opens a path to lower-volume fusion reactors, in accordance with the fusion power scaling proportional to β2Bt4V. Modular approach then becomes an alternative to high power, GW-scale Fusion reactors [4,5]. Feasibility of low-power compact ST reactor module and physics and engineering challenges of the accelerated, ST path to Fusion Power are discussed in this paper, on example of the first our prototype on this route, high-field compact spherical tokamak ST40.

Mufflers represent devices used to reduce sound and pulsations for internal combustion engines and other equipment like volumetric compressors. Depending on application they are designed to reduce low, medium or high frequency pulsations. The main design is represented by acoustic filters which use the acoustic analogy method. Dealing with low frequency pulsations this type of filters result in bulky constructions. The use of metamaterials results in a more compact design for these type of mufflers. This paper investigates by numerical simulations the transmission loss (TL) of such muffler based on acoustic black hole (ABH) metamaterial principle. In the first part of the paper the FEM results are compared with the acoustic measurements performed on an adapted impedance tube, in order to validate the model. In the second part the influences of the geometric parameters (length of the muffler, lamellae depth and thickness) will be investigated. The comparative analysis between the FEM and the measured results indicates good agreement. The geometric parameters analysis highlighted that the acoustic attenuation can be increased by using a long muffler.

In this paper is presented a wind turbine model operating in the maximum power zone and an H∞ controller is synthesized for the system. The developed turbine model consists of: a model of the wind speed, mechanical and electrical model of the generator and a model of the tower oscillations. The controller adjusts the pitch angle of the blades so that the rotor angular velocity stays close to its nominal value and as a result the tower oscillations are decreased. Finally, the operation of the closed-loop system model is validated by simulationsIn this paper is presented a wind turbine model operating in the maximum power zone and an H∞ controller is synthesized for the system. The developed turbine model consists of: a model of the wind speed, mechanical and electrical model of the generator and a model of the tower oscillations. The controller adjusts the pitch angle of the blades so that the rotor angular velocity stays close to its nominal value and as a result the tower oscillations are decreased. Finally, the operation of the closed-loop system model is validated by simulations

The generator is one of the tools that used in power system circuit. The working system of electrical generators is converted the mechanical energy from an external source into electrical energy as output. The generator works by exploiting the electric flux generated by a magnetic field that passes through the rotation of the coil on the generator engine. Both of these are things that affect the efficiency level of the generator. If the efficiency of a generator is higher so the electrical energy generated is also greater. In this paper will be analyzed theoretically mathematically to improve the efficiency of the alternating current generator. The analytical review will be performed on magnetic field strength and coil rotation speed. With the increase of these two factors is expected to increase generator efficiency is also increasing so that the electrical energy which is the output of the generator system is also higher.The generator is one of the tools that used in power system circuit. The working system of electrical generators is converted the mechanical energy from an external source into electrical energy as output. The generator works by exploiting the electric flux generated by a magnetic field that passes through the rotation of the coil on the generator engine. Both of these are things that affect the efficiency level of the generator. If the efficiency of a generator is higher so the electrical energy generated is also greater. In this paper will be analyzed theoretically mathematically to improve the efficiency of the alternating current generator. The analytical review will be performed on magnetic field strength and coil rotation speed. With the increase of these two factors is expected to increase generator efficiency is also increasing so that the electrical energy which is the output of the generator system is also higher.

This paper reports the feasibility of measuring weak magnetic fields generated by the electrical activity of the heart using a portable tri-axial fluxgate magnetometer inside a magnetically shielded room. Measurement of Magnetocardiogram (MCG) signals could be successfully demonstrated from a healthy subject using a novel set-up involving a reference fluxgate sensor which simultaneously measures the magnetic fields associated with the ECG waveform measured on the same subject. The timing information provided by R wave peaks of ECG recorded by the reference sensor is utilized to generate trigger locked average of the sensor output of the measurement fluxgate, and extract MCG signals in all the three orthogonal directions (X, Y and Z) on the anterior thorax. It is expected that such portable room temperature measurements using fluxgate sensor could assist in validating the direction of the equivalent current dipole associated with the electrical activity of the human heart. This is somewhat difficult in conventional MCG measurements using SQUID sensors, which usually furnish only the z component of the magnetic field and its spatial derivatives.This paper reports the feasibility of measuring weak magnetic fields generated by the electrical activity of the heart using a portable tri-axial fluxgate magnetometer inside a magnetically shielded room. Measurement of Magnetocardiogram (MCG) signals could be successfully demonstrated from a healthy subject using a novel set-up involving a reference fluxgate sensor which simultaneously measures the magnetic fields associated with the ECG waveform measured on the same subject. The timing information provided by R wave peaks of ECG recorded by the reference sensor is utilized to generate trigger locked average of the sensor output of the measurement fluxgate, and extract MCG signals in all the three orthogonal directions (X, Y and Z) on the anterior thorax. It is expected that such portable room temperature measurements using fluxgate sensor could assist in validating the direction of the equivalent current dipole associated with the electrical activity of the human heart. This is somewhat difficult in con...

In the present paper, the study of electrostatic electron cyclotron parallel flow velocity shear instability in presence of perpendicular inhomogeneous DC electric field has been carried out in the magnetosphere of Saturn. Dimensionless growth rate variation of electron cyclotron waves has been observed with respect to k⊥ ρe for various plasma parameters. Effect of velocity shear scale length (Ae), inhomogeneity (P/a), the ratio of ion to electron temperature (Ti/Te) and density gradient (enρe) on the growth of electron cyclotron waves in the inner magnetosphere of Saturn has been studied and analyzed. The mathematical formulation and computation of dispersion relation and growth rate have been done by using the method of characteristic solution and kinetic approach. This theoretical analysis has been done taking the relevant data from the Cassini spacecraft in the inner magnetosphere of Saturn. We have considered ambient magnetic field data and other relevant data for this study at the radial distance of ∼4.82-5.00 Rs. In our study velocity shear and ion to electron temperature ratio have been observed to be the major sources of free energy for the electron cyclotron instability. The inhomogeneity of electric field caused a small noticeable impact on the growth rate of electrostatic electron cyclotron instability. Density gradient has been observed playing stabilizing effect on electron cyclotron instability.In the present paper, the study of electrostatic electron cyclotron parallel flow velocity shear instability in presence of perpendicular inhomogeneous DC electric field has been carried out in the magnetosphere of Saturn. Dimensionless growth rate variation of electron cyclotron waves has been observed with respect to k⊥ ρe for various plasma parameters. Effect of velocity shear scale length (Ae), inhomogeneity (P/a), the ratio of ion to electron temperature (Ti/Te) and density gradient (enρe) on the growth of electron cyclotron waves in the inner magnetosphere of Saturn has been studied and analyzed. The mathematical formulation and computation of dispersion relation and growth rate have been done by using the method of characteristic solution and kinetic approach. This theoretical analysis has been done taking the relevant data from the Cassini spacecraft in the inner magnetosphere of Saturn. We have considered ambient magnetic field data and other relevant data for this study at the radial distance of...

Steady-state operation of a fusion neutron source (FNS) requires plasma heating and current drive by means of additional power delivered by neutral beams. Six neutral beam injectors (NBI) will provide DEMO-FNS machine with additional heating power up to 30 MW, with neutral particle energy 500 keV. NBI systems developed for ITER can serve as the prototype for DEMO-FNS, as both systems have similar ion source current, with accelerated beam power in ITER NBI (1 MeV) being twice as large as in DEMO-FNS. The paper describes the NBI system with account of its integration to DEMO-FNS tokamak complex.Steady-state operation of a fusion neutron source (FNS) requires plasma heating and current drive by means of additional power delivered by neutral beams. Six neutral beam injectors (NBI) will provide DEMO-FNS machine with additional heating power up to 30 MW, with neutral particle energy 500 keV. NBI systems developed for ITER can serve as the prototype for DEMO-FNS, as both systems have similar ion source current, with accelerated beam power in ITER NBI (1 MeV) being twice as large as in DEMO-FNS. The paper describes the NBI system with account of its integration to DEMO-FNS tokamak complex.

The aim of the paper is to analyze the synchronization phenomenon of a rotating structure composed of three beams attached to a rigid hub. It is assumed in the calculations that one beam is 10% thicker comparing to the remaining ones. Furthermore, two possible variants of excitation are considered: (a) torque given by harmonic function or (b) torque produced by a chaotic oscillator. Next, the equations have been solved numerically and the resonance curves and time series have been analyzed in terms of synchronized motion of the hub and blades of the rotor. The influence of hub’s mass moment of inertia have been checked as well. For the system with chaotic Duffing oscillator Poincare maps have been obtained.The aim of the paper is to analyze the synchronization phenomenon of a rotating structure composed of three beams attached to a rigid hub. It is assumed in the calculations that one beam is 10% thicker comparing to the remaining ones. Furthermore, two possible variants of excitation are considered: (a) torque given by harmonic function or (b) torque produced by a chaotic oscillator. Next, the equations have been solved numerically and the resonance curves and time series have been analyzed in terms of synchronized motion of the hub and blades of the rotor. The influence of hub’s mass moment of inertia have been checked as well. For the system with chaotic Duffing oscillator Poincare maps have been obtained.

In this paper, we deal with the oblique electromagnetic electron cyclotron (EMEC) waves in the Uranus magnetosphere. The expression of the dispersion relation is plotted by using the method of the feature solution. After the kinetic method, the growth rate and the actual frequency of the EMEC wave are studied theoretically in the Uranian system. NASA, Voyager 2, the observed results of the space detectors show that the spin axes of the planets are abnormally oriented and that there are more particles in the high energy tail of the Uranian magnetospheric plasma. Therefore, this paper uses the Kappa distribution instead of the usual Maxwell distribution. The study extends to the tilt propagation of EMEC waves, which has a change in temperature anisotropy and propagation angle with respect to the direction of the magnetic field. These parameters were found to support the growth rate of EMEC waves. However, the response of the actual frequency of these waves is not the same as the rate of growth in all cases. These results apply to the detailed comparison of planetary studies of the space plasma environment and the magnetosphere system.

The Rim-driven Thruster (RDT) is a new type of marine electric thruster proposed in recent years. In this paper, the author proposed a new type of permanent magnet synchronous rim thrust motor (RTM). The motor uses a Halbach array permanent magnet rotor, which can improve the torque density of the propulsion motor by utilizing the unilateral magnetic field of the Halbach array. In this paper, the electromagnetic properties of the motor were measured and compared with that of the ordinary magnetic pole motor through numerical analysis. The results show that at the same power, the new motor can significantly reduce the thickness of the rotor’s permanent magnet and yoke core, and has obvious advantages in power density, moment of inertia, dynamic performance, and cost.

This paper presents the experimental results of the Cleanergy's C11S solar engine-generator tested in the KTH solar simulator. The paper focuses on the analysis of the thermal performance of the ca ...

The paper reviews the publications on low-frequency vibration in power plants. It is noted that the regulatory literature poorly defines the issues of rating and diagnosing self-excited and subharmonic vibrations. Analysis of the literature and ISO standards shows that despite the considerable experience gained by specialists in low-frequency vibration control, a number of issues, such as subharmonic resonances and nonlinear properties of complicated multi-seated rotor systems supported by journal bearings, are still understudied and require further calculations and experiments. The paper presents some results obtained in experiments of low-frequency vibrations for a rotor supported by journal bearings and having a residual deflection. The experimental results confirmed the classical hysteresis of self-excited vibrations – the difference in the boundaries of self-excited vibrations during ascent and descent is about 4 Hz. The arears of appearance and disappearance of subharmonic vibrations are shown using the spectral characteristics of vibrations and cascade spectra.

I summarize in this paper our previous works on the spin polaron theory as a mechanism for high temperature superconductivity in the finite temperature (Matsubara) Green’s function method. In this formulation, some bulk thermodynamic properties of high-Tc materials like entropy and specific heat are treated. The hole spectral function is likewise derived. Single-particle tunneling current is calculated for normal metal-superconductor and superconductor-superconductor junctions. With an effective Hamiltonian derived from this theory, the Josephson tunneling current between two high temperature superconductors is obtained. Current problems like mobility of holes, calculation of energy gap function, the triplet pairing mechanism, among others, are also discussed in this paper, all using the spin polaron formulation.

The measurement of geomagnetic field conducted by underwater robot is widely used during cruise, however, it is often influenced by the strong electromagnetic interference of the other large-scale electronic equipment on the robot itself. The leakage magnetic field of high-power brushless DC motor (BLDCM) has been identified as one of the main interference source. To obtain accurate geomagnetic data, it is necessary to analyze the magnetic field characteristics of the leakage field of BLDCM. In this paper, we build a two-dimensional BLDCM model. In addition, we present the rotor’s leakage magnetic field when the BLDCM is static, dynamic leakage magnetic field of the stator and rotor when BLDCM is working and the near-field characteristic of BLDCM’s leakage magnetic field. Finally, this paper studies the relationship between the frequency of the magnetic field change and the speed of the BLDCM, which can be used to eliminate the AC interference magnetic field. Therefore the measuring accuracy of the geomag...

A new type of power plant. i.e, Electric Power Confined Piston Engine, is invented by combining the free piston engine and the crank connecting rod mechanism of the traditional internal combustion engine. Directly using the reciprocating movement of the piston, this new engine converts the heat energy produced by fuel to electrical energy and output it. The paper expounds the working mechanism of ECPE and establishes the kinematics and dynamics equations. Furthermore, by using the analytic method, the ECPE electromagnetic force is solved at load cases. Finally, in the simulation environment of MARLAB, the universal characteristic curve is obtained in the condition of rotational speed n between 1000 r/min and 2400 r/min, throttle opening α between 30% and 100%.A new type of power plant. i.e, Electric Power Confined Piston Engine, is invented by combining the free piston engine and the crank connecting rod mechanism of the traditional internal combustion engine. Directly using the reciprocating movement of the piston, this new engine converts the heat energy produced by fuel to electrical energy and output it. The paper expounds the working mechanism of ECPE and establishes the kinematics and dynamics equations. Furthermore, by using the analytic method, the ECPE electromagnetic force is solved at load cases. Finally, in the simulation environment of MARLAB, the universal characteristic curve is obtained in the condition of rotational speed n between 1000 r/min and 2400 r/min, throttle opening α between 30% and 100%.

The paper describes an advanced gyro-based measuring system comprising a CGV-4K central vertical gyro and a G-3M gyrocompass. The advanced system provides additional functions that help measure unsprung mass rotation angles about a vertical axis, rolling angles, trim angles and movements of the unsprung masses of the front (ap and al) and rear b axes when a car wheel hits a single obstruction. The paper also describes the operation of the system, which measures movements of unsprung masses about the body of a car when it hits a single obstruction. The paper presents the dependency diagrams ap = f(t) and al = f(t) for front and rear wheels respectively, as well as b = f(t) for a rear left wheel, which were determined experimentally. Test results for a car equipped with an advanced gyro-based measuring system moving around a circle can form a basis for developing a mathematical model of the process.

Injection of high energy beams of neutral particles is a method for plasma heating in fusion devices. The ITER injector, and its prototype MITICA (Megavolt ITER Injector and Concept Advancement), are large extrapolations from existing devices. Therefore nu merical modeling is needed to set thermo - mechanical requirements for all beam - facing components. As the power and charge deposition originates from several sources (primary beam, co - accelerated electrons, and secondary production by beam - gas, beam - surface, and electron - surface interaction), the beam propagation along the beam line is simulated by comprehensive 3D models. This paper presents a comparative study between two codes: BTR has been used for several years in the design of the ITER HNB components; the SAMANTHA code was independently developed and includes additional phenomena, like secondary particles generated by collision of beam particles with the background gas. The code comparison is valuable in the perspective of the upcoming experimental oper ations, in order to prepare a reliable numerical support to the interpretation of experimental measurements in the beam test facilities. The power density maps calculated on the Electrostatic Residual Ion Dump (ERID) is chosen as the benchmark, as they dep end on the electric and magnetic fields as well as on the evolution of the beam species via interaction with the gas. Finally the paper shows additional results provided by SAMANTHA, like the power deposition onto the Cryopumps due to secondary electrons accelerated by the ERID fringe - field

The Coherent electron Cooling (CeC) Proof of Principle (PoP) experiment is proposed to be installed in the Relativistic Heavy Ion Collider (RHIC) to demonstrate proton and ion beam cooling with this new technique that may increase the beam luminosity in certain cases, by as much as tenfold. Within the scope of this project, a 112 MHz, 2MeV Superconducting Radio Frequency (SRF) electron gun and a 704 MHz 20MeV 5-cell SRF cavity will be installed at IP2 in the RHIC ring. The superconducting RF electron gun will be cooled in a liquid helium bath at 4.4 K. The 704 MHz 5-cell SRF cavity will be cooled in a super-fluid helium bath at 2.0 K. This paper discusses the cryogenic systems designed for both cavities. For the 112 MHz cavity cryogenic system, a condenser/boiler heat exchanger is used to isolate the cavity helium bath from pressure pulses and microphonics noise sources. For the 704 MHz 5-cell SRF cavity, a heat exchanger is also used to isolate the SRF cavity helium bath from noise sources in the sub-atmospheric pumping system operating at room temperature. Detailed designs, thermal analyses and discussions for both systems will be presented in this paper.

Since the early'70s AWE has focussed on indirect drive as a means of accessing high energy density regimes. We give a brief historical perspective of this work and the rationale for the construction of the ORION laser. This laser is currently in commissioning and is scheduled to commence experiments in 2012. The ORION laser is configured to provide long pulses (~ 1ns) with a high degree of pulse shape flexibility, together with synchronised short pulse (~1ps) irradiation. The paper describes how this combination should enable pressures in excess of 1 Gb and temperatures of greater than 500 eV to be achieved. The ability to access and diagnose such conditions has applications in many fields; examples are given in planetary science, astrophysics and inertial fusion energy. For these applications we first describe the approach to measuring equation of state and opacity properties in the high energy density regime. Such properties are then incorporated into integrated computer simulation codes and validated against laser experiments, some of which have been conducted recently at the OMEGA laser at the University of Rochester. The paper concludes with a discussion of inertial fusion energy and the new high energy density regimes that this would access, if successful.

Ions with energies above the plasma ion temperature (also called super thermal, hot or energetic particles - EP) are utilized in laboratory experiments as a plasma heat source to compensate for energy loss. Sources for super thermal ions are direct injection via neutral beams, RF heating and fusion reactions. Being super thermal, ions have the potential to induce instabilities of a certain class of magnetohydrodynamics (MHD) cavity modes, in particular, various Alfven and Alfvenacoustic Eigenmodes. It is an area where ideal MHD and kinetic theories can be tested with great accuracy. This paper touches upon key motivations to study the energetic ion interactions with MHD modes. One is the possibility of controlling the heating channel of present and future tokamak reactors via EP transport. In some extreme circumstances, uncontrolled instabilities led to vessel wall damages. This paper reviews some experimental and theoretical advances and the developments of the predictive tools in the area of EP wave int...

This paper describes industrial charged particle beamline technologies and design approaches. Beamlines accommodate myriad constraints in the radioisotope production, electron beam processing, and ion implantation market segments, and some very strange yet interesting solutions result. In this paper, a detailed look at a particular injection beamline solution gives some sense of the complexity of research and development required, and the sophistication of the beamline solutions that are utilized. A brief review of beamline applications in each industrial segment follows.

High intensity Accelerator is being studied all over world for numerous applications, which includes the waste transmutation, spallation neutron source and material irradiation facilities. The R/D activities of the technology of High intensity accelerator are also developed in China for some year, and have some good facilities around China. This paper will reports the status of some high intensity accelerators and neutron source in China, which including ADS/RFQ; CARR; CSNS; PKUNIFTY & CPHS. This paper will emphatically report the Compact Pulsed Hadron Source (CPHS) led by the Department of Engineering Physics of Tsinghua University in Beijing, China.

The James Webb Telescope is the successor to the Hubble Telescope and will be placed in an orbit of 1.5 million km from earth. Before launch in 2014, the telescope will be tested in NASA Johnson Space Center’s (JSC) space simulation chamber, Chamber A. The tests will be conducted at deep space conditions. Chamber A’s helium cryo‐panels are currently cooled down to 20 K by two Linde 3.5 kW helium refrigerators. The new 12.5 kW, 20‐K helium coldbox described in this paper is part of the upgrade to the chamber systems for this large test program. The Linde coldbox will provide refrigeration in several operating modes where the temperature of the chamber is being controlled with a high accuracy due to the demanding NASA test requirements. The implementation of two parallel expansion turbine strings and the Ganni cycle—Floating Pressure process results in a highly efficient and flexible process that minimizes the electrical input power. This paper will describe the collaboration and execution of the coldbox project.

This paper starts from a brief overview of theoretical studies of high‐gradient accelerating structures at the University of Maryland. The rest of the paper is devoted to the analysis of ion bombardment of small protrusions in such structures. First, this problem is studied analytically. Then, some results of particle‐in‐cell simulations performed with the use of code WARP are presented and discussed.

In this paper we present the perspectives of the development of the XUV laser sources using High‐power laser facilities. We focus our paper on the present statuts of the LASERIX facility and especially its role in the development of the XUV laser sources considering the French “Institut de la Lumiere Extreme “(ILE) and the potential European project Extreme Light Infrastructure (ELI). Finally, we present one typical experiment performed in that context with the facility. It is dedicated to the fundamental study irradiation induced damage in DNA samples.

The ‘Herschel Space Observatory’ is the fourth cornerstone mission in the ‘Horizons 2000’ program of the European Space Agency (ESA), with the objectives to study the formation of galaxies in the early universe and the creation of stars. It will observe the chemical composition of surfaces and atmospheres of comets, planets and natural satellites, and examine the molecular chemistry of the universe. Herschel was launched into an operational Lissajous orbit around the Earth‐Sun L2 point by an Ariane 5 on May 14th 2009 to perform photometer and spectrometer measurements, covering the full far infrared to sub‐millimeter wavelength range from 60 to 670 micrometers during its operational lifetime of more than four years.This paper gives a short overview of the cryogenic system and summarises the cryogenic aspects of the different phases of the acceptance test campaign, including the launch preparation phase as well as the post‐launch transient cool‐down of the system, the verification of the Passive Phase Separator performance and the evaluation of pressure drop measurements performed on the helium venting system. The impact of thermo‐acoustic oscillations within the helium subsystem is described, which were present during the initial cool‐down test phase. A comparison of measurements to numerical analysis results is shown.The ‘Herschel Space Observatory’ is the fourth cornerstone mission in the ‘Horizons 2000’ program of the European Space Agency (ESA), with the objectives to study the formation of galaxies in the early universe and the creation of stars. It will observe the chemical composition of surfaces and atmospheres of comets, planets and natural satellites, and examine the molecular chemistry of the universe. Herschel was launched into an operational Lissajous orbit around the Earth‐Sun L2 point by an Ariane 5 on May 14th 2009 to perform photometer and spectrometer measurements, covering the full far infrared to sub‐millimeter wavelength range from 60 to 670 micrometers during its operational lifetime of more than four years.This paper gives a short overview of the cryogenic system and summarises the cryogenic aspects of the different phases of the acceptance test campaign, including the launch preparation phase as well as the post‐launch transient cool‐down of the system, the verification of the Passive Phase Sepa...

This paper revisits some content in the First International Symposium on Beamed Energy Propulsion in 2002 related to the concept of propellantless in‐space propulsion utilizing an external high energy laser to provide momentum to an ultralightweight (gossamer) spacecraft. The design and construction of the NanoSail‐D solar sail demonstration spacecraft has demonstrated in space flight hardware the concept of small, very light—yet capable—spacecraft. The results of the Joint High Power Solid State Laser (JHPSSL) have also increased the effectiveness and reduced the cost of an entry level laser source. This paper identifies the impact from improved system parameters on current mission applications.

Accelerating gradient is a key parameter of the accelerating structure in large linac facilities, like future Linear Collider. In room temperature accelerating structures the gradient is limited mostly by breakdown phenomena, caused by high surface electric fields or pulse surface heating. High power processing is a necessary procedure to clean surface and improve the gradient. In the best tested X-band structures the achieved gradient is exceed 100 MV/m in of {approx}200 ns pulses for breakdown rate of {approx} 10{sup -7}. Gradient limit depends on number of factors and no one theory which can explain all sets of experimental results and predict gradient in new accelerating structure. In paper we briefly overview the recent experimental results of breakdown studies, progress in understanding of gradient limitations and scaling laws. Although superconducting rf technology has been adopted throughout the world for ILC, it has frequently been difficult to reach the predicted performance in these structures due to a number of factors: multipactoring, field emission, Q-slope, thermal breakdown. In paper we are discussing all these phenomena and the ways to increase accelerating gradient in SC cavity, which are a part of worldwide R&D program.

There have been many significant experimental and theoretical advances recently with regard to the production of relativistic electron beams using laser wakefield accelerators (LWFA) driven by high power short pulse lasers. In particular, there has been an explosion of interest in this field following the discovery of methods to generate such beams with low energy spread. In recent work by many groups around the world the energy and quality of these beams has been improved and a more complete understanding of the “bubble” regime of electron acceleration has been obtained, enabling a significant improvement in the output electron beam stability. The 2008 Advanced Accelerator Concepts workshop in Santa Cruz CA brought together the leading groups engaged in this research from around the world. This paper will summarize the major results presented at the conference. Further details on the work described here can be found in the other related papers in these proceedings.

High amplitude coherent electron‐trajectories have been seen in 3D particle‐in‐cell simulations of the colliding pulse injection scheme of laser‐wakefield accelerators in the bubble regime, and explained as a consequence of laser‐driven coherent betatron oscillation in our recent paper [K. Nemeth et al., Phys. Rev. Lett. 100, 095002 (2008)]. In the present paper we provide more details on the shape of the trajectories, their relationship to the phase velocity of the laser and indicate the dependence of the phenomenon on the accuracy of the numerical representation and choice of laser/plasma parameters.

The paper discusses the proposed improvement of a High‐Frequency Relic Gravitational Wave (HFRGW) detector designed by Li, Baker, Fang, Stephenson and Chen in order to greatly improve its sensitivity. The improved detector is inspired by the Laser Interferometer Gravitational Observatory or LIGO, but is sensitive to the high‐frequency end of the gravitational‐wave spectrum. As described in prior papers it utilizes the Gertsenshtein effect, which introduces the conversion of gravitational waves to electromagnetic (EM) waves in the presence of a static magnetic field. Such a conversion, if it leads to photons moving in a direction perpendicular to the plane of the EM waves and the magnetic field, will allow for ultra‐high sensitivity HFRGW detection. The use of sensitive microwave, single photon detectors such as a circuit QED and/or the Rydberg Atom Cavity Detector, or off‐the‐shelf detectors, could lead to such detection. When the EM‐detection photons are focused at the microwave detectors by fractal‐membrane reflectors sensitivity is also improved. Noise sources external to the HFRGW detector will be eliminated by placing a tight mosaic of superconducting tiles (e.g., YBCO) and/or fractal membranes on the interior surface of the detector's cryogenic containment vessel in order to provide a perfect Faraday cage. Internal thermal noise will be eliminated by means of a microwave absorbing (or reflecting) interior enclosure shaped to conform to a high‐intensity continuous microwave Gaussian beam (GB), will reduce any background photon flux (BPF) noise radiated normal to the GB's axis. Such BPF will be further attenuated by a series of microwave absorbing baffles forming tunnels to the sensitive microwave detectors on each side of the GB and at right angles to the static magnetic field. A HFGW detector of bandwidth of 1 KHz to 10 KHz or less in the GHz band has been selected. It is concluded that the utilization of the new ultra‐high‐sensitivity microwave detectors, together with the increased microwave power and magnet intensity will allow for a detection of high‐frequency gravitational waves (HFGWs) exhibiting amplitudes, A, of the time‐varying spacetime strains on the order of 10−30 to 10−34.

A helium cryogenic system with cooling capacity of 1 kW at 4.5 K was set up at Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing. This helium refrigeration system is dedicated for the cooling of two superconducting radio frequency (SRF) cavities, two interaction region superconducting quadrupole magnets (SCQ), the Beijing Spectrometer III (BESIII) solenoid magnet (SSM), which are the key items of the upgrade project of Beijing Electron-Positron Collider (BEPCII). Commissioning with the SSM and SCQ magnets has been carried out, which will be introduced in this paper. The cryogenic system of BESIII magnet showed very robust as SSM quenched. This paper presents the overall status and some test results of the cryogenic system.

This paper describes the characteristics of the multihole collimator gamma camera that is simulated using the combination of the Monte Carlo N‐Particles Code (MCNP) version 5 and in‐house software. The model is constructed based on the GCA‐7100A Toshiba Gamma Camera at the Royal Surrey County Hospital, Guildford, Surrey, UK. The characteristics are analyzed based on the spatial resolution of the images detected by the Sodium Iodide (NaI) detector. The result is recorded in a list‐mode file referred to as a PTRAC file within MCNP5. All pertinent nuclear reaction mechanisms, such as Compton and Rayleigh scattering and photoelectric absorption are undertaken by MCNP5 for all materials encountered by each photon. The experiments were conducted on Tl‐201, Co‐57, Tc‐99 m and Cr‐51 radio nuclides. The comparison of full width half maximum value of each datasets obtained from experimental work, simulation and literature are also reported in this paper. The relationship of the simulated data is in agreement with the experimental results and data obtained in the literature. A careful inspection at each of the data points of the spatial resolution of Tc‐99 m shows a slight discrepancy between these sets. However, the difference is very insignificant, i.e. less than 3 mm only, which corresponds to a size of less than 1 pixel only (of the segmented detector).

The present author has previously published a series of papers at STAIF exploring the interactions of very‐high frequency gravitational waves (VHFGWs, typically around 3 GHz) with superconductors. One important design concept is a novel variable‐focus lens that would be invaluable in the design of advanced GW optics for communications applications. This achieves all‐electrical focusing with no moving parts. The design was based upon the published calculations of Li and Torr (in 1992 and 1993) claiming to show that GWs propagate inside superconductors with a phase velocity reduction by a factor ng≈300× and a corresponding wavenumber increase. Successful demonstration of this lens would also serve as a confirmation of the controversial Li and Torr result. The possibility remains that the Li and Torr result is valid in principle but with a much reduced numerical value of ng arising from the linearizing assumptions made in their papers. (A much increased value of ng arising from the same reason is also possib...

Wind is regarded as the popular passive cooling resource against hot climate in summer. It can transfer heat from human bodies, when the air temperature is lower than the skin temperature. This concept works indoors as well as outdoors. The present paper refers to the numerical simulation of air velocity and temperature concerning single—sided naturally ventilated buildings and more specifically the special case in which air from the external environment is brought inside the building through openings that have the same direction. The paper draws attention to the physical procedures governing air movement during the single—sided natural ventilation. The study presents a mathematical model, implemented in a general computer code, that can provide detailed information on velocity and temperature, prevailing in three‐dimensional single—sided ventilated buildings with openings of any geometrical complexity, for given external meteorological conditions. The mathematical model involves the partial differential ...

The EM nonlinearity of the 2000–2001 Podkletnov superconductor impulse experiments was predicted (in hindsight) by Maker and the author in 2002 through the derivation of an impulse velocity equation, which was built on previously work by Maker. This paper shows that this impulse velocity equation can be written in terms of the time average nonlinear impulse thrust equation derived in a 2006 paper by the author to correlate the reported inductive capacitor experiments. The time averaged thrust for the 2000–2001 Podkletnov superconductor impulse experiments and a nonlinearity factor is then calculated. These indicate that the thrust on the superconductor could have been in the Newton range, which is much higher than the milli‐Newtons currently being seen in the inductive capacitor experiments.

The present author previously published a paper at STAIF 2006 detailing the design of a novel variable‐focus lens for use with very‐high frequency gravitational waves (VHFGWs, typically around 3GHz). Such a lens would be invaluable in the design of advanced GW optics for communications applications since focusing would be achievable electrically with no moving parts. The design was based upon the published calculations of Li and Torr (in 1992 and 1993) claiming to show that GWs propagate inside superconductors with a phase velocity reduction by a factor n ∼ 300× and a corresponding wavenumber increase. Successful demonstration of this lens would also confirm the controversial Li and Torr result. Type II superconductors do not completely expel large magnetic fields, but instead allow vortices of magnetic flux to channel the magnetic field through the material. Within these vortices, the superconductor is magnetically quenched and so has properties similar or identical to those of non‐superconductors. Varying the applied magnetic field varies the proportion of material quenched and superconducting. For GW wavelengths significantly larger than the typical vortex separation, the GW propagation through a type II superconductor is therefore dependent upon the applied magnetic field. Since a conventional optical lens may be regarded as a position‐dependent phase shifter, and the VHFGW phase‐shift depends upon the applied magnetic field, the design of a VHFGW lens therefore reduces to producing a suitable applied magnetic field variation that gives a technologically‐useful spatial variation of phase shift. Thus, in this paper, a modified method of producing the required magnetic field is introduced, as well as a more detailed discussion of the VHFGW propagation through the superconducting material with an applied field. The component described is unparalleled in conventional optics because the focal length is varied completely electrically and has no mechanical moving parts. This gives the potential of much greater reliability than could be obtained by copying equivalent optical glass lens designs, and the control can also be considerably faster (limited only by circuit design). Therefore, fast auto‐focusing, zooming, and imaging tomography of VHFGW using electronic servos may be feasible.

This paper describes a new monochromator design for a bending magnet beamline of the Swiss Light Source synchrotron facility. The beamline optics is based on a horizontally deflecting spherical grating monochromator (SGM) with two gratings at a constant deviation angle. It covers a photon energy range from 200 eV to 1000 eV. This paper concentrates on the original flexure‐based mechanisms with partially parallel kinematics invented and designed for this monochromator, as well as on the lessons learned from the assembly and testing of the system.

Future LISA and LIGO projects may require gratings for interferometry and angular sensing to accurately monitor test mass positions. This paper summarizes some techniques used to create gratings on materials that will make up the test masses of next generation gravitational‐wave detectors. As grating tip/tilt sensing will require two‐dimensional grating structures with duty cycles and unit cell shapes that are as of yet undetermined, we concentrate on approaches that allow us to readily generate complex patterns. This paper discusses e‐beam lithography for dielectric surfaces, and mechanical trans‐imprinting and focused ion‐beam writing for gold. These methods are more flexible than traditional techniques, such as the holographic exposure of photoresist with multiple laser beams. Grating patterns suitable for optical sensing have been successfully demonstrated on the surfaces of dielectric materials and gold. Their diffraction efficiencies have been measured to be sufficiently high for tip/tilt sensing.

In this paper, the overall objective is to investigate a method to calculate the so‐called equivalent surface currents, arisen from an incoming high frequency plane wave, on a long and slightly curved cylindrical conductor, such as a wire. One application for this calculation method is the study of how radar waves are affected by wires mounted near a radar antenna. The paper also includes a brief discussion on how this surface current can be used to calculate the scattered electric field from the conductor.

In light of the recent developments with the International Linear Collider (ILC), and the recommendation to utilize “Cold” technology for this future particle accelerator, this paper will present the lessons learned from the recently concluded Spallation Neutron Source (SNS) superconducting radio frequency (SRF) cryomodule production run at the Thomas Jefferson National Accelerator Facility (Jefferson Lab). Over the past twenty years Jefferson Lab has worked with industry to successfully design, manufacture, test and commission more SRF cryomodules than any other entity in the United States. The knowledge gained from the design and fabrication of the SNS prototype, eleven — 0.61 (medium) beta and the twelve — 0.81 (high) beta cryomodules, will prove to be an effective asset to the ILC project. After delivery of the final production cryomodule in March 2005, design and fabrication data will be collected, evaluated and presented to make this information beneficial for future particle accelerator projects. Recommendations with respect to these findings will also be presented as an integral part of this paper.

The paper reviews some of the recent studies of applications of weakly ionized plasmas to supersonic/hypersonic flight. Plasmas can be used simply as means of delivering energy (heating) to the flow, and also for electromagnetic flow control and magnetohydrodynamic (MHD) power generation. Plasma and MHD control can be especially effective in transient off‐design flight regimes. In cold air flow, nonequilibrium plasmas must be created, and the ionization power budget determines design, performance envelope, and the very practicality of plasma/MHD devices. The minimum power budget is provided by electron beams and repetitive high‐voltage nanosecond pulses, and the paper describes theoretical and computational modeling of plasmas created by the beams and repetitive pulses. The models include coupled equations for non‐local and unsteady electron energy distribution function (modeled in forward‐back approximation), plasma kinetics, and electric field. Recent experimental studies at Princeton University have successfully demonstrated stable diffuse plasmas sustained by repetitive nanosecond pulses in supersonic air flow, and for the first time have demonstrated the existence of MHD effects in such plasmas. Cold‐air hypersonic MHD devices are shown to permit optimization of scramjet inlets at Mach numbers higher than the design value, while operating in self‐powered regime. Plasma energy addition upstream of the inlet throat can increase the thrust by capturing more air (Virtual Cowl), or it can reduce the flow Mach number and thus eliminate the need for an isolator duct. In the latter two cases, the power that needs to be supplied to the plasma would be generated by an MHD generator downstream of the combustor, thus forming the “reverse energy bypass” scheme. MHD power generation on board reentry vehicles is also discussed.

In 1966 George Marx in his historical paper in Nature introduced the concept of interstellar ship driven by radiation pressure from terrestrial X‐ray laser. He named the new concept “laser propulsion”. Marx arrived to conclusion that maximum efficiency of such ship will be achieved at β → 1.0. One year later, J.L. Redding published a different solution, leading to maximum efficiency at β = 0.414. As it will be shown in this paper, neither was right in their assessments of optimal conditions. Correct solution will be presented in order to solve the problem of relativistic mirror.

RF breakdown is one of the major factors determining performance of high power rf components and rf sources. RF breakdown limits working power and produces irreversible surface damage. The breakdown limit depends on the rf circuit, structure geometry, and rf frequency. It is also a function of the input power, pulse width, and surface electric and magnetic fields. In this paper we discuss multi‐megawatt operation of X‐band rf structures at pulse width on the order of one microsecond. These structures are used in rf systems of high gradient accelerators. Recent experiments at Stanford Linear Accelerator Center (SLAC) have explored the functional dependence of breakdown limit on input power and pulse width. The experimental data covered accelerating structures and waveguides. Another breakdown limit of accelerating structures was associated with high magnetic fields found in waveguide‐to‐structure couplers. To understand and quantify these limits we simulated 3D structures with the electrodynamics code Ansoft HFSS and the Particle‐In‐Cell code MAGIC3D. Results of these simulations together with experimental data will be discussed in this paper.

Note: Invited paper - AIP Conference Proceedings 687, 297-304, ISBN 0-7354-0158-6 (invited paper) - part 1: 15th Topical Conference on Radio Frequency Power in Plasmas, Moran, Wyoming, USA, May 2003 (see also #3643) Reference CRPP-CONF-2003-058 Record created on 2008-05-13, modified on 2017-05-12

This paper describes the currently proposed systems for electron beam position monitoring (EBPM) and diagnostics for the DIAMOND synchrotron. Although the basic requirements have remained unaltered, the philosophy of implementation has been subject to change, influenced by the experiences of other national light sources, and the emerging availability of commercial equipment, suited to the needs of DIAMOND. This paper focuses in greatest detail on the storage ring systems, including data acquisition and control. Details of Total Current Monitor (TCM) systems, and an active, beam position based interlock system for protecting ID vessels against thermal damage, by beam mis‐steer, are also included.

This paper will review some of the recent developments in the area of high-brightness electron beams. Most of the paper will be devoted to emittance compensation concepts relating to high-brightness beam production in photoinjectors. Recent interpretation of emittance compensation and the residual emittance after compensation in terms of wave breaking has provided valuable insights into the process. Wave breaking also appears to have an influence on emittance growth and halo production in transport lines, which we will briefly discuss. There has been advances in understanding the emittance growth of bunches in circular motion, particularly related to the cancellation of longitudinal and transverse energy-independent forces. Finally, some non-intercepting bunch length and emittance diagnostic approaches will be reviewed.