WorldWideScience

Sample records for external rf power

  1. Negative ion source with external RF antenna

    Science.gov (United States)

    Leung, Ka-Ngo; Hahto, Sami K.; Hahto, Sari T.

    2007-02-13

    A radio frequency (RF) driven plasma ion source has an external RF antenna, i.e. the RF antenna is positioned outside the plasma generating chamber rather than inside. The RF antenna is typically formed of a small diameter metal tube coated with an insulator. An external RF antenna assembly is used to mount the external RF antenna to the ion source. The RF antenna tubing is wound around the external RF antenna assembly to form a coil. The external RF antenna assembly is formed of a material, e.g. quartz, which is essentially transparent to the RF waves. The external RF antenna assembly is attached to and forms a part of the plasma source chamber so that the RF waves emitted by the RF antenna enter into the inside of the plasma chamber and ionize a gas contained therein. The plasma ion source is typically a multi-cusp ion source. A converter can be included in the ion source to produce negative ions.

  2. RF Power Amplifier Analysis

    Directory of Open Access Journals (Sweden)

    M. Lokay

    1993-04-01

    Full Text Available The special program is presented for the demonstration of RF power transistor amplifiers for the purposes of the high-school education in courses of radio transmitters. The program is written in Turbo Pascal 6. 0 and enables to study the waveforms in selected points of the amplifier and to draw the trajectories of the working point in a plot of output transistor characteristics.

  3. RF power generation

    CERN Document Server

    Carter, R G

    2011-01-01

    This paper reviews the main types of r.f. power amplifiers which are, or may be, used for particle accelerators. It covers solid-state devices, tetrodes, inductive output tubes, klystrons, magnetrons, and gyrotrons with power outputs greater than 10 kW c.w. or 100 kW pulsed at frequencies from 50 MHz to 30 GHz. Factors affecting the satisfactory operation of amplifiers include cooling, matching and protection circuits are discussed. The paper concludes with a summary of the state of the art for the different technologies.

  4. Externally RF Power Supply Control Technology for Fuze%引信体外射频电源供电控制方法

    Institute of Scientific and Technical Information of China (English)

    常悦; 李杰; 周晓东

    2016-01-01

    To control the power supply of the externally RF power for fuze,the supply control method of the externally RF power for fuze based on the launch recoil overload sensor was proposed.The launch recoil over-load sensor could distinguish the difference environment between ammunition service and ammunition launch, and generated the control signal to switch on the circuit of power supply of the externally RF power,when the cutter cut off the wire by the pull of recoil,which was hold upper by spring.To avoid false detonation,the state of wire was checked during fuze setting,and the control and detonate circuit of fuze became short-circuit if the wire was broken before launch.The prototype test results showed that the externally RF power was discharged and the control and detonate circuit of fuze begins to start-up just during muzzle with the supply control method. The sensor and control circuit had advantages of simple and easily miniaturization.%针对引信体外射频电源的供电控制问题,提出了基于发射后坐过载传感器的引信体外射频电源供电控制方法。该方法采用后坐过载传感器,通过弹簧约束切刀并在后坐过载作用下切断导体的方式识别发射环境,并控制供电电路通断,实现引信体外射频电源在出炮口附近对发火控制与起爆电路供电;在引信装定时检测传感器导体的通断,提高引信体外射频电源供电安全性。原理样机验证试验结果表明,该方法能够控制引信体外射频电源仅在出炮口附近对发火控制与起爆电路供电,发射过载传感器与上电控制电路简单、易于小型化。

  5. Other RF power sources

    Energy Technology Data Exchange (ETDEWEB)

    Kurkin, G.Ya. [Budker Inst. of Nuclear Physics, Novosibirsk (Russian Federation)

    1999-09-01

    The main subjects discussed in this paper are as follows. Triode tube; main characteristics of the equivalent schematic of the amplifying stage. Requirements for operation of a triode stage loaded with an accelerating cavity. Influence of parameters of the output stage and transmission line length on the output impedance of RF system for the beam. Typical design of the power output stage. Magnetron, travelling-wave tube, principles of operation, main parameters. Magnetron loaded with a microtron cavity, methods of coupling, requirements for stable operation. Magnicon - BHF generator with a circular deflection of the electron beam, principle of operation, results of development. (author)

  6. Automatic calorimetry system monitors RF power

    Science.gov (United States)

    Harness, B. W.; Heiberger, E. C.

    1969-01-01

    Calorimetry system monitors the average power dissipated in a high power RF transmitter. Sensors measure the change in temperature and the flow rate of the coolant, while a multiplier computes the power dissipated in the RF load.

  7. Linearisation of RF Power Amplifiers

    DEFF Research Database (Denmark)

    Nielsen, Per Asbeck

    2001-01-01

    This thesis deals with linearisation techniques of RF power amplifiers (PA), PA design techniques and integration of the necessary building blocks in a CMOS technology. The opening chapters introduces the theory of transmitter architectures, RF-signal representation and the principles of digital...... modulation. Furthermore different types of power amplifiers, models and measures of non-linearities are presented. A chapter is also devoted to different types of linearisation systems. The work carried out and described in this thesis can be divided into a more theoretical and system oriented treatment...... the polar loop architecture and it’s suitability to modern digital transmitters is discussed. A proposal of an architecture that is suitable for digital transmitters, which means that it has an interface to the digital back-end, defined by low-pass signals in polar form, is presented. Simulation guidelines...

  8. RF power coupling for the CSNS DTL

    Science.gov (United States)

    Liu, Hua-Chang; Peng, Jun; Yin, Xue-Jun; Ouyang, Hua-Fu; Fu, Shi-Nian

    2011-01-01

    The China Spallation Neutron Source (CSNS) drift tube linac (DTL) consists of four tanks and each tank is fed by a 2.5 MW klystron. Accurate predication of RF coupling between the RF cavity and ports is very important for DTL RF coupler design. An iris-type coupler is chosen to couple the RF power to the DTL accelerating cavity. The physical design of the DTL coupler and the calculations of RF coupling between the cavity and coupler are carried out. The results from the numerical simulations are in excellent agreement with the analytical results.

  9. RF power coupling for the CSNS DTL

    Institute of Scientific and Technical Information of China (English)

    LIU Hua-Chang; PENG Jun; YIN Xue-Jun; OUYANG Hua-Fu; FU Shi-Nian

    2011-01-01

    The China Spallation Neutron Source(CSNS)drift tube linac(DTL)consists of four tanks and each tank is fed by a 2.5 MW klystron.Accurate predication of RF coupling between the RF cavity and ports is very important for DTL RF coupler design.An iris-type coupler is chosen to couple the RF power to the DTL accelerating cavity.The physical design of the DTL coupler and the calculations of RF coupling between the cavity and coupler are carried out.The results from the numerical simulations are in excellent agreement with the analytical results.

  10. LTE RF subsystem power consumption modeling

    DEFF Research Database (Denmark)

    Musiige, Deogratius; Vincent, Laulagnet; Anton, François;

    2012-01-01

    This paper presents a new power consumption emulation model, for all possible scenarios of the RF subsystem, when transmitting a LTE signal. The model takes the logical interface parameters, Tx power, carrier frequency and bandwidth between the baseband and RF subsystem as inputs to compute the p...

  11. Design of RF Power System for CPHS

    Science.gov (United States)

    Cheng, Cheng; Du, Taibin; Guan, Xialing

    The Compact Pulsed Hadron Source (CPHS) system has been proposed and designed by the Department of Engineering Physics of Tsinghua University in Beijing, China. It consists of an accelerator front-end-a highintensity ion source, a 3 MeV radiofrequency quadrupole linac (RFQ), and a 13 MeV drift-tube linac (DTL), a neutron target station, and some experimental stations. In design of our RF power supply, both RFQ and DTL share a single klystron which is capable of 2.5 MW peak RF power and a 3.33% duty factor. The 325 MHz klystron contains a modulating anode and has a 100 kW average output power. Portions of the RF power system, such as pulsed high voltage power supply, modulator, crowbar protection and RF power transmission are all presented in details in this paper.

  12. RF waveguide phase-directed power combiners

    Energy Technology Data Exchange (ETDEWEB)

    Nantista, Christopher D.; Dolgashev, Valery A.; Tantawi, Sami G.

    2017-05-02

    High power RF phase-directed power combiners include magic H hybrid and/or superhybrid circuits oriented in orthogonal H-planes and connected using E-plane bends and/or twists to produce compact 3D waveguide circuits, including 8.times.8 and 16.times.16 combiners. Using phase control at the input ports, RF power can be directed to a single output port, enabling fast switching between output ports for applications such as multi-angle radiation therapy.

  13. RF Power and HOM Coupler Tutorial

    Energy Technology Data Exchange (ETDEWEB)

    Rusnak, B

    2003-10-28

    Radio frequency (RF) couplers are used on superconducting cavities to deliver RF power for creating accelerating fields and to remove unwanted higher-order mode power for reducing emittance growth and cryogenic load. RF couplers in superconducting applications present a number of interdisciplinary design challenges that need to be addressed, since poor performance in these devices can profoundly impact accelerator operations and the overall success of a major facility. This paper will focus on critical design issues for fundamental and higher order mode (HOM) power couplers, highlight a sampling of reliability-related problems observed in couplers, and discuss some design strategies for improving performance.

  14. RF power generation for future linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Fowkes, W.R.; Allen, M.A.; Callin, R.S.; Caryotakis, G.; Eppley, K.R.; Fant, K.S.; Farkas, Z.D.; Feinstein, J.; Ko, K.; Koontz, R.F.; Kroll, N.; Lavine, T.L.; Lee, T.G.; Miller, R.H.; Pearson, C.; Spalek, G.; Vlieks, A.E.; Wilson, P.B.

    1990-06-01

    The next linear collider will require 200 MW of rf power per meter of linac structure at relatively high frequency to produce an accelerating gradient of about 100 MV/m. The higher frequencies result in a higher breakdown threshold in the accelerating structure hence permit higher accelerating gradients per meter of linac. The lower frequencies have the advantage that high peak power rf sources can be realized. 11.42 GHz appears to be a good compromise and the effort at the Stanford Linear Accelerator Center (SLAC) is being concentrated on rf sources operating at this frequency. The filling time of the accelerating structure for each rf feed is expected to be about 80 ns. Under serious consideration at SLAC is a conventional klystron followed by a multistage rf pulse compression system, and the Crossed-Field Amplifier. These are discussed in this paper.

  15. Multicusp ion source with external rf antenna for production of protons

    Science.gov (United States)

    Hahto, S. K.; Hahto, S. T.; Ji, Q.; Leung, K. N.; Wilde, S.; Foley, E. L.; Grisham, L. R.; Levinton, F. M.

    2004-02-01

    Proton beams are needed in neutral-beam injection for diagnostic development of an internal magnetic field measurement. High proton fraction, low axial energy spread, current density in excess of 30 mA/cm2, and a parallel ion beam with cw operation are the requirements for the ion source/extraction system. A multicusp-type ion source with an external rf antenna was constructed at Lawrence Berkeley National Laboratory. A proton fraction of 85% and proton current density of 32 mA/cm2 were achieved at 1.8 kW of rf power. Plasma parameters were measured with a rf compensated Langmuir probe.

  16. An RF-input outphasing power amplifier with RF signal decomposition network

    OpenAIRE

    Barton, Taylor W.; Perreault, David J.

    2015-01-01

    This work presents an outphasing power amplifier that directly amplifies a modulated RF input. The approach eliminates the need for multiple costly IQ modulators and baseband signal component separation found in conventional outphasing power amplifier systems, which have previously required both an RF carrier input and a separate baseband input to synthesize a modulated RF output. A novel RF signal decomposition network enables direct RF-input / RF-output outphasing by directly synthesizing t...

  17. Computer simulations for rf design of a Spallation Neutron Source external antenna H ion source

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sung-Woo [ORNL; Goulding, Richard Howell [ORNL; Kang, Yoon W [ORNL; Shin, Ki [ORNL; Welton, Robert F [ORNL

    2010-01-01

    Electromagnetic modeling of the multicusp external antenna H ion source for the Spallation Neutron Source SNS has been performed in order to optimize high-power performance. During development of the SNS external antenna ion source, antenna failures due to high voltage and multicusp magnet holder rf heating concerns under stressful operating conditions led to rf characteristics analysis. In rf simulations, the plasma was modeled as an equivalent lossy metal by defining conductivity as . Insulation designs along with material selections such as ferrite and Teflon could be included in the computer simulations to compare antenna gap potentials, surface power dissipations, and input impedance at the operating frequencies, 2 and 13.56 MHz. Further modeling and design improvements are outlined in the conclusion.

  18. Low reflectance high power RF load

    Energy Technology Data Exchange (ETDEWEB)

    Ives, R. Lawrence; Mizuhara, Yosuke M.

    2016-02-02

    A load for traveling microwave energy has an absorptive volume defined by cylindrical body enclosed by a first end cap and a second end cap. The first end cap has an aperture for the passage of an input waveguide with a rotating part that is coupled to a reflective mirror. The inner surfaces of the absorptive volume consist of a resistive material or are coated with a coating which absorbs a fraction of incident RF energy, and the remainder of the RF energy reflects. The angle of the reflector and end caps is selected such that reflected RF energy dissipates an increasing percentage of the remaining RF energy at each reflection, and the reflected RF energy which returns to the rotating mirror is directed to the back surface of the rotating reflector, and is not coupled to the input waveguide. Additionally, the reflector may have a surface which generates a more uniform power distribution function axially and laterally, to increase the power handling capability of the RF load. The input waveguide may be corrugated for HE11 mode input energy.

  19. Multicusp ion source with external RF antenna for production of H- ions

    Science.gov (United States)

    Kalvas, T.; Hahto, S. K.; Vainionpää, J. H.; Leung, K. N.; Wilde, S. B.; Mandrillon, P.

    2007-08-01

    A multicusp ion source with modular design was developed at LBNL for production of H- ions. The source consists of a front plate, two multicusp front chambers, a quartz flange with external 3-loop RF antenna and a rear multicusp chamber. The source has LaB6 sputtering target at the rear chamber to lower the work function of the surfaces by coating them with LaB6 and an external cesium oven on the front plate. The front plate also has an integrated collar and filter magnets to cool plasma near the extraction. The collar also enables the use of cesium and LaB6 surface effects. The rear chamber is equipped with three vacuum feed-throughs for operation with two gases and a pressure measurement. Current density of over 10 mA/cm2 of H- has been measured with e/I- ratio being ˜100 when the source was operated with only 1000 W of cw RF power. Negative ion production was enhanced using cesium, Xe gas mixing and LaB6 deposition to the source surfaces. When the front plate with filter magnets is removed, the source produces large amounts of H+. Current density of 110 mA/cm2 with 1800 W RF power at 2.3 Pa source pressure was measured with over 90 % atomic species. A long operation lifetime is excepted as the external RF antenna is not exposed to plasma.

  20. Overview of High Power Vacuum Dry RF Load Designs

    Energy Technology Data Exchange (ETDEWEB)

    Krasnykh, Anatoly [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-27

    A specific feature of RF linacs based on the pulsed traveling wave (TW) mode of operation is that only a portion of the RF energy is used for the beam acceleration. The residual RF energy has to be terminated into an RF load. Higher accelerating gradients require higher RF sources and RF loads, which can stably terminate the residual RF power. RF feeders (from the RF source though the accelerating section to the load) are vacuumed to transmit multi-megawatt high power RF. This overview will outline vacuumed RF loads only. A common method to terminate multi-MW RF power is to use circulated water (or other liquid) as an absorbing medium. A solid dielectric interface (a high quality ceramic) is required to separate vacuum and liquid RF absorber mediums. Using such RF load approaches in TW linacs is troubling because there is a fragile ceramic window barrier and a failure could become catastrophic for linac vacuum and RF systems. Traditional loads comprising of a ceramic disk have limited peak and average power handling capability and are therefore not suitable for high gradient TW linacs. This overview will focus on ''vacuum dry'' or ''all-metal'' loads that do not employ any dielectric interface between vacuum and absorber. The first prototype is an original design of RF loads for the Stanford Two-Mile Accelerator.

  1. Conceptual SPL RF Main Power Coupler design

    CERN Document Server

    Montesinos, Eric

    2011-01-01

    While the upgrade plans of the LHC injectors had to be reduced in scope in 2010, the Superconducting Proton Linac (SPL) remains a fundamental element of plans for a possible future neutrino facility. Prototyping work is therefore continuing at CERN and the current focus is on the test of a first four cavity SPL-like cryomodule with full power. This report summarizes the parameters for the Main Power Coupler design as discussed and approved within the ‘Review of SPL RF power couplers’, held at CERN in March 2010.

  2. Rf power sources for linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Allen, M.A.; Callin, R.S.; Caryotakis, G.; Deruyter, H.; Eppley, K.R.; Fant, K.S.; Farkas, Z.D.; Fowkes, W.R.; Hoag, H.A.; Feinstein, J.; Ko, K.; Koontz, R.F.; Kroll, N.M.; Lavine, T.L.; Lee, T.G.; Loew, G.A.; Miller, R.H.; Nelson, E.M.; Ruth, R.D.; Vlieks, A.E.; Wang, J.W.; Wilson, P.B. (Stanford Linear Accelerator Center, Menlo Park, CA (USA)); Boyd, J.K.; Houk, T.; Ryne, R.D.; Westenskow, G.A.; Yu, S.S. (Lawrence Live

    1990-06-01

    The next generation of linear colliders requires peak power sources of over 200 MW per meter at frequencies above 10 GHz at pulse widths of less than 100 nsec. Several power sources are under active development, including a conventional klystron with rf pulse compression, a relativistic klystron (RK) and a crossed-field amplifier. Power from one of these has energized a 0.5 meter two- section High Gradient Accelerator (HGA) and accelerated a beam at over 80 MeV meter. Results of tests with these experimental devices are presented here.

  3. Rf-to-dc power converters for wireless powering

    KAUST Repository

    Ouda, Mahmoud Hamdy

    2016-12-01

    Various examples are provided related to radio frequency (RF) to direct current (DC) power conversion. In one example, a RF-to-DC converter includes a fully cross-coupled rectification circuit including a pair of forward rectifying transistors and a feedback circuit configured to provide feedback bias signals to gates of the pair of forward rectifying transistors via feedback branch elements. In another example, a method includes receiving a radio frequency (RF) signal; rectifying the RF signal via a fully cross-coupled rectification circuit including a pair of forward rectifying transistors; and providing a DC output voltage from an output connection of the fully cross-coupled rectification circuit, where gating of the pair of forward rectifying transistors is controlled by feedback bias signals provided to gates of the pair of forward rectifying transistors via feedback branch elements.

  4. New Driver For The Powerful Output Rf Amplifier Of Mmf Dtl Rf System

    CERN Document Server

    Kvasha, A I; Vassilyev, A G

    2004-01-01

    More than 30 years ago a few powerful vacuum tubes were specially designed and produced in the former design office Swetlana for the Moscow meson factory DTL RF system. Among them was tetrode GI-51A with output pulse RF power up to 300 kW at frequency 198.2 MHz, which was used as driver for RF power amplifier with output RF pulse power (2-3) MW. In connection with well-known events in our country manufacture of these tubes, including GI-51A was finished about 10 years ago. In "SED-SPb" (successor of the design office Swetlana) triode GI-57A was offered instead of GI-51A. In this paper results of calculations and design of RF amplifier with new triode are presented. Preliminary results of RF amplifier tests, also presented in the paper, showed that triode GI-57A will be able successfully used in the DTL RF system channels.

  5. VERSE-Guided Numerical RF Pulse Design: A Fast Method for Peak RF Power Control

    Science.gov (United States)

    Lee, Daeho; Grissom, William A.; Lustig, Michael; Kerr, Adam B.; Stang, Pascal P.; Pauly, John M.

    2013-01-01

    In parallel excitation, the computational speed of numerical radiofrequency (RF) pulse design methods is critical when subject dependencies and system nonidealities need to be incorporated on-the-fly. One important concern with optimization-based methods is high peak RF power exceeding hardware or safety limits. Hence, online controllability of the peak RF power is essential. Variable-rate selective excitation pulse reshaping is ideally suited to this problem due to its simplicity and low computational cost. In this work, we first improve the fidelity of variable-rate selective excitation implementation for discrete-time waveforms through waveform oversampling such that variable-rate selective excitation can be robustly applied to numerically designed RF pulses. Then, a variable-rate selective excitation-guided numerical RF pulse design is suggested as an online RF pulse design framework, aiming to simultaneously control peak RF power and compensate for off-resonance. PMID:22135085

  6. Electromagnetic Design of New RF Power Couplers for the S-DALINAC

    CERN Document Server

    Kunze, Marco; Brunken, M; Gräf, H D; Richter, Achim

    2004-01-01

    New rf power couplers for the Superconducting Darmstadt Linear Accelerator (S-DALINAC) injector have to be designed to transfer rf power of up to 2 kW to the electron beam. This allows injector operation at beam currents from 0.15 mA to 0.2 mA and electron energies up to 14 MeV. The new couplers should possibly provide a external Q of 5·106

  7. High power solid state rf amplifier for proton accelerator.

    Science.gov (United States)

    Jain, Akhilesh; Sharma, Deepak Kumar; Gupta, Alok Kumar; Hannurkar, P R

    2008-01-01

    A 1.5 kW solid state rf amplifier at 352 MHz has been developed and tested at RRCAT. This rf source for cw operation will be used as a part of rf system of 100 MeV proton linear accelerator. A rf power of 1.5 kW has been achieved by combining output power from eight 220 W rf amplifier modules. Amplifier modules, eight-way power combiner and divider, and directional coupler were designed indigenously for this development. High efficiency, ease of fabrication, and low cost are the main features of this design.

  8. Low power smartdust receiver with novel applications and improvements of an RF power harvesting circuit

    Science.gov (United States)

    Salter, Thomas Steven, Jr.

    Smartdust is the evolution of wireless sensor networks to cubic centimeter dimensions or less. Smartdust systems have advantages in cost, flexibility, and rapid deployment that make them ideal for many military, medical, and industrial applications. This work addresses the limitations of prior works of research to provide sufficient lifetime and performance for Smartdust sensor networks through the design, fabrication and testing of a novel low power receiver for use in a Smartdust transceiver. Through the novel optimization of a multi-stage LNA design and novel application of a power matched Villard voltage doubler circuit, a 1.0 V, 1.6 mW low power On-Off Key (OOK) receiver operating at 2.2 GHz is fabricated using 0.13 um CMOS technology. To facilitate data transfer in adverse RF propagation environments (1/r3 loss), the chip receives a 1 Mbps data signal with a sensitivity of -90 dBm while consuming just 1.6 nJ/bit. The receiver operates without the addition of any external passives facilitating its application in Smartdust scale (cm 3) wireless sensor networks. This represents an order of magnitude decrease in power consumption over receiver designs of comparable sensitivity. In an effort to further extend the lifetime of the Smartdust transceiver, RF power harvesting is explored as a power source. The small scale of Smartdust sensor networks poses unique challenges in the design of RF power scavenging systems. To meet these challenges, novel design improvements to an RF power scavenging circuit integrated directly onto CMOS are presented. These improvements include a reduction in the threshold voltage of diode connected MOSFET and sources of circuit parasitics that are unique to integrated circuits. Utilizing these improvements, the voltage necessary to drive Smartdust circuitry (1 V) with a greater than 20% RF to DC conversion efficiency was generated from RF energy levels measured in the environment (66 uW). This represents better than double the RF to DC

  9. Series-Tuned High Efficiency RF-Power Amplifiers

    DEFF Research Database (Denmark)

    Vidkjær, Jens

    2008-01-01

    An approach to high efficiency RF-power amplifier design is presented. It addresses simultaneously efficiency optimization and peak voltage limitations when transistors are pushed towards their power limits.......An approach to high efficiency RF-power amplifier design is presented. It addresses simultaneously efficiency optimization and peak voltage limitations when transistors are pushed towards their power limits....

  10. RF power coupling for the CSNS DTL

    Institute of Scientific and Technical Information of China (English)

    刘华昌; 彭军; 殷学军; 欧阳华甫; 傅世年

    2011-01-01

    The China Spallation Neutron Source (CSNS) drift tube linac (DTL) consists of four tanks and each tank is fed by a 2.5 MW klystron. Accurate predication of RF coupling between the RF cavity and ports is very important for DTL RF coupler design. An iris-ty

  11. A prototype RF power source for CSNS/RCS

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    A prototype RF power source has been built to supply high RF power to a ferrite-loaded cavity, which is a part of R&D of the Rapid Cycling Synchrotron of China Spallation Neutron Source (CSNS/RCS). A direct fast RF feedback amplifier, a 4:1 impedance transformer and auto tuning grid were locally located to compensate the heavy beam loading of CSNS/RCS. Design and commissioning of the RF power source is discussed here, also with some advice on system improvement.

  12. RF characterization and testing of ridge waveguide transitions for RF power couplers

    Science.gov (United States)

    Kumar, Rajesh; Jose, Mentes; Singh, G. N.; Kumar, Girish; Bhagwat, P. V.

    2016-12-01

    RF characterization of rectangular to ridge waveguide transitions for RF power couplers has been carried out by connecting them back to back. Rectangular waveguide to N type adapters are first calibrated by TRL method and then used for RF measurements. Detailed information is obtained about their RF behavior by measurements and full wave simulations. It is shown that the two transitions can be characterized and tuned for required return loss at design frequency of 352.2 MHz. This opens the possibility of testing and conditioning two transitions together on a test bench. Finally, a RF coupler based on these transitions is coupled to an accelerator cavity. The power coupler is successfully tested up to 200 kW, 352.2 MHz with 0.2% duty cycle.

  13. Power outages, power externalities, and baby booms.

    Science.gov (United States)

    Burlando, Alfredo

    2014-08-01

    Determining whether power outages have significant fertility effects is an important policy question in developing countries, where blackouts are common and modern forms of family planning are scarce. Using birth records from Zanzibar, this study shows that a month-long blackout in 2008 caused a significant increase in the number of births 8 to 10 months later. The increase was similar across villages that had electricity, regardless of the level of electrification; villages with no electricity connections saw no changes in birth numbers. The large fertility increase in communities with very low levels of electricity suggests that the outage affected the fertility of households not connected to the grid through some spillover effect. Whether the baby boom is likely to translate to a permanent increase in the population remains unclear, but this article highlights an important hidden consequence of power instability in developing countries. It also suggests that electricity imposes significant externality effects on rural populations that have little exposure to it.

  14. Design of an L-band normally conducting RF gun cavity for high peak and average RF power

    Science.gov (United States)

    Paramonov, V.; Philipp, S.; Rybakov, I.; Skassyrskaya, A.; Stephan, F.

    2017-05-01

    To provide high quality electron bunches for linear accelerators used in free electron lasers and particle colliders, RF gun cavities operate with extreme electric fields, resulting in a high pulsed RF power. The main L-band superconducting linacs of such facilities also require a long RF pulse length, resulting in a high average dissipated RF power in the gun cavity. The newly developed cavity based on the proven advantages of the existing DESY RF gun cavities, underwent significant changes. The shape of the cells is optimized to reduce the maximal surface electric field and RF loss power. Furthermore, the cavity is equipped with an RF probe to measure the field amplitude and phase. The elaborated cooling circuit design results in a lower temperature rise on the cavity RF surface and permits higher dissipated RF power. The paper presents the main solutions and results of the cavity design.

  15. Indoor Wireless RF Energy Transfer for Powering Wireless Sensors

    Directory of Open Access Journals (Sweden)

    H. Visser

    2012-12-01

    Full Text Available For powering wireless sensors in buildings, rechargeable batteries may be used. These batteries will be recharged remotely by dedicated RF sources. Far-field RF energy transport is known to suffer from path loss and therefore the RF power available on the rectifying antenna or rectenna will be very low. As a consequence, the RF-to-DC conversion efficiency of the rectenna will also be very low. By optimizing not only the subsystems of a rectenna but also taking the propagation channel into account and using the channel information for adapting the transmit antenna radiation pattern, the RF energy transport efficiency will be improved. The rectenna optimization, channel modeling and design of a transmit antenna are discussed.

  16. High power RF systems for the BNL ERL project

    Energy Technology Data Exchange (ETDEWEB)

    Zaltsman, A.; Lambiase, R.

    2011-03-28

    The Energy Recovery Linac (ERL) project, now under construction at Brookhaven National Laboratory, requires two high power RF systems. The first RF system is for the 703.75 MHz superconducting electron gun. The RF power from this system is used to drive nearly half an Ampere of beam current to 2 MeV. There is no provision to recover any of this energy so the minimum amplifier power is 1 MW. It consists of 1 MW CW klystron, transmitter and power supplies, 1 MW circulator, 1 MW dummy load and a two-way power splitter. The second RF system is for the 703.75 MHz superconducting cavity. The system accelerates the beam to 54.7 MeV and recovers this energy. It will provide up to 50 kW of CW RF power to the cavity. It consists of 50 kW transmitter, circulator, and dummy load. This paper describes the two high power RF systems and presents the test data for both.

  17. Fabrication and low-power RF test of C-band RF gun

    Energy Technology Data Exchange (ETDEWEB)

    Taira, Y., E-mail: yoshitaka-taira@aist.go.jp; Kuroda, R.; Tanaka, M.; Kato, H.; Suzuki, R.; Toyokawa, H.

    2014-07-15

    A C-band RF gun for compact radiation sources such as high-energy X-ray and terahertz radiation sources is developed at AIST and is designed to work at a frequency of 5.3 GHz. The total length of this equipment is about 1.5 m. An electron beam with a maximum energy of 0.9 MeV can be generated when the peak electric field is 85 MV/m, corresponding to an RF peak power of 600 kW. A coniferous-tree-type carbon nanostructure is used for the field emission cathode. We present the structural design and fabrication of the C-band RF cavity and a low-power RF test of it.

  18. RF-MEMS Switched Varactors for Medium Power Applications

    CERN Document Server

    Maury, F; Crunteanu, A; Conseil, F; Blondy, P

    2008-01-01

    In RF (Radio Frequency) domain, one of the limitations of using MEMS (Micro Electromechanical Systems) switching devices for medium power applications is RF power. Failure phenomena appear even for 500 mW. A design of MEMS switched capacitors with an enhanced topology is presented in this paper to prevent it. This kind of device and its promising performances will serve to fabricate a MEMS based phase shifter able to work under several watts.

  19. Effects of Various RF Powers on CdTe Thin Film Growth Using RF Magnetron Sputtering

    Science.gov (United States)

    Alibakhshi, Mohammad; Ghorannevis, Zohreh

    2016-09-01

    Cadmium telluride (CdTe) film was deposited using the magnetron sputtering system onto a glass substrate at various deposition times and radio frequency (RF) powers. Ar gas was used to generate plasma to sputter the CdTe atoms from CdTe target. Effects of two experimental parameters of deposition time and RF power were investigated on the physical properties of the CdTe films. X-ray Diffraction (XRD) analysis showed that the films exhibited polycrystalline nature of CdTe structure with the (111) orientation as the most prominent peak. Optimum condition to grow the CdTe film was obtained and it was found that increasing the deposition time and RF power increases the crystallinity of the films. From the profilometer and XRD data's, the thicknesses and crystal sizes of the CdTe films increased at the higher RF power and the longer deposition time, which results in affecting the band gap as well. From atomic force microscopy (AFM) analysis we found that roughnesses of the films depend on the deposition time and is independent of the RF power.

  20. Electrodeless lighting RF power source development. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-30

    An efficient, solid state RF power source has been developed on this NICE project for exciting low power electrodeless lamp bulbs. This project takes full advantage of concurrent advances in electrodeless lamp technology. Electrodeless lamp lighting systems utilizing the sulfur based bulb type developed by Fusion Lighting, Inc., is an emerging technology which is based on generating light in a confined plasma created and sustained by RF excitation. The bulb for such a lamp is filled with a particular element and inert gas at low pressure when cold. RF power from the RF source creates a plasma within the bulb which reaches temperatures approaching those of high pressure discharge lamp plasmas. At these temperatures the plasma radiates substantial visible light with a spectrum similar to sunlight.

  1. A capacitive RF power sensor based on MEMS technology

    NARCIS (Netherlands)

    Fernandez, Luis Jose

    2005-01-01

    Existing power sensors for RF signals are based on thermistors, diodes and thermocouples. These power sensors are used as terminating devices and therefore they dissipate the complete incoming signal. Furthermore, new telecommunication systems require low weight, volume and power consumption and a h

  2. A capacitive rf power sensor based on mems technology

    NARCIS (Netherlands)

    Fernandez, L.J.

    2005-01-01

    Existing power sensors for RF signals are based on thermistors, diodes and thermocouples. These power sensors are used as terminating devices and therefore they dissipate the complete incoming signal. Furthermore, new telecommunication systems require low weight, volume and power consumption and a

  3. Low power RF amplifier circuit for ion trap applications

    Science.gov (United States)

    Noriega, J. R.; García-Delgado, L. A.; Gómez-Fuentes, R.; García-Juárez, A.

    2016-09-01

    A low power RF amplifier circuit for ion trap applications is presented and described. The amplifier is based on a class-D half-bridge amplifier with a voltage mirror driver. The RF amplifier is composed of an RF class-D amplifier, an envelope modulator to ramp up the RF voltage during the ion analysis stage, a detector or amplitude demodulation circuit for sensing the output signal amplitude, and a feedback amplifier that linearizes the steady state output of the amplifier. The RF frequency is set by a crystal oscillator and the series resonant circuit is tuned to the oscillator frequency. The resonant circuit components have been chosen, in this case, to operate at 1 MHz. In testings, the class-D stage operated at a maximum of 78 mW at 1.1356 MHz producing 225 V peak.

  4. RF power consumption emulation optimized with interval valued homotopies

    DEFF Research Database (Denmark)

    Musiige, Deogratius; Anton, François; Yatskevich, Vital

    2011-01-01

    the baseband and the RF system as inputs to compute the emulated power dissipation of the RF device. The emulated power, in between the measured points corresponding to the discrete values of the logical interface parameters is computed as a polynomial interpolation using polynomial basis functions......This paper presents a methodology towards the emulation of the electrical power consumption of the RF device during the cellular phone/handset transmission mode using the LTE technology. The emulation methodology takes the physical environmental variables and the logical interface between....... The evaluation of polynomial and spline curve fitting models showed a respective divergence (test error) of 8% and 0.02% from the physically measured power consumption. The precisions of the instruments used for the physical measurements have been modeled as intervals. We have been able to model the power...

  5. Development of a 500 MHz high power RF test stand

    Institute of Scientific and Technical Information of China (English)

    PAN Wei-Min; SHA Peng; HUANG Tong-Ming; MA Qiang; WANG Guang-Wei; LIN Hai-Ying; ZHAO Guang-Yuan; SUN Yi; XU Bo; WANG Qun-Yao

    2012-01-01

    A flexible high power RF test stand has been designed and constructed at IHEP to test a variety of 500 MHz superconducting RF components for the upgrade project of the Beijing Electron Positron Collider (BEPC Ⅱ ),such as the input coupler,the higher order modes (HOMs) absorber and so on.A high power input coupler has been conditioned and tested with the RF power up to 250 kW in continuous wave (CW),traveling wave (TW) mode and 150 kW CW in standing wave (SW) mode.A prototype of the HOMs absorber has been tested to absorb power of 4.4 kW.An introduction of the test stand design,construction and high power tests is presented in this paper.

  6. A HIGH POWER RF COUPLER DESIGN FOR MUON COOLING RF CAVITIES.

    Energy Technology Data Exchange (ETDEWEB)

    CORLETT,J.; LI,DERUN; RIMMER,R.; HOLTKAMP,N.; MORETTI,A.; KIRK,H.G.

    1999-03-29

    We present a high power RF coupler design for an interleaved {pi}/2 805 MHz standing wave accelerating structure proposed for an muon cooling experiment at FNAL. The coupler, in its simplest form, is a rectangular waveguide directly connected to an accelerating Cell through an open slot on the cavity side-wall or end-plates. Two of such couplers are needed to feed the interleaved cavities. Current high power RF test requires the coupler to be at critical coupling. Numerical simulations on the coupler designs using MAFIA will be presented.

  7. High power RF window deposition apparatus, method, and device

    Energy Technology Data Exchange (ETDEWEB)

    Ives, Lawrence R.; Lucovsky, Gerald; Zeller, Daniel

    2017-07-04

    A process for forming a coating for an RF window which has improved secondary electron emission and reduced multipactor for high power RF waveguides is formed from a substrate with low loss tangent and desirable mechanical characteristics. The substrate has an RPAO deposition layer applied which oxygenates the surface of the substrate to remove carbon impurities, thereafter has an RPAN deposition layer applied to nitrogen activate the surface of the substrate, after which a TiN deposition layer is applied using Titanium tert-butoxide. The TiN deposition layer is capped with a final RPAN deposition layer of nitridation to reduce the bound oxygen in the TiN deposition layer. The resulting RF window has greatly improved titanium layer adhesion, reduced multipactor, and is able to withstand greater RF power levels than provided by the prior art.

  8. High Power RF Test Facility at the SNS

    CERN Document Server

    Kang, Yoon W; Campisi, Isidoro E; Champion, Mark; Crofford, Mark; Davis, Kirk; Drury, Michael A; Fuja, Ray E; Gurd, Pamela; Kasemir, Kay-Uwe; McCarthy, Michael P; Powers, Tom; Shajedul Hasan, S M; Stirbet, Mircea; Stout, Daniel; Tang, Johnny Y; Vassioutchenko, Alexandre V; Wezensky, Mark

    2005-01-01

    RF Test Facility has been completed in the SNS project at ORNL to support test and conditioning operation of RF subsystems and components. The system consists of two transmitters for two klystrons powered by a common high voltage pulsed converter modulator that can provide power to two independent RF systems. The waveguides are configured with WR2100 and WR1150 sizes for presently used frequencies: 402.5 MHz and 805 MHz. Both 402.5 MHz and 805 MHz systems have circulator protected klystrons that can be powered by the modulator capable of delivering 11 MW peak and 1 MW average power. The facility has been equipped with computer control for various RF processing and complete dual frequency operation. More than forty 805 MHz fundamental power couplers for the SNS superconducting linac (SCL) cavitites have been RF conditioned in this facility. The facility provides more than 1000 ft2 floor area for various test setups. The facility also has a shielded cave area that can support high power tests of normal conducti...

  9. X-band RF power sources for accelerator applications

    Energy Technology Data Exchange (ETDEWEB)

    Kirshner, Mark F.; Kowalczyk, Richard D.; Wilsen, Craig B.; True, Richard B.; Simpson, Ian T.; Wray, John T., E-mail: mark.kirshner@L-3com.com [L-3 Communications Electron Devices, San Carlos, CA (United States)

    2011-07-01

    The majority of medical and industrial linear accelerators (LINACs) in use today operate at S-band. To reduce size and weight, these systems are gradually migrating toward X-band. The new LINACs will require suitable RF components to power them. In anticipation of this market, L-3 Communications Electron Devices Division (EDD) has recently developed a suite of RF sources operating at 9.3 GHz to complement our existing S-band product line. (author)

  10. Design and manufacture of the RF power supply and RF transmission line for SANAEM project Prometheus

    Science.gov (United States)

    Turemen, G.; Ogur, S.; Ahiska, F.; Yasatekin, B.; Cicek, E.; Ozbey, A.; Kilic, I.; Unel, G.; Alacakir, A.

    2017-08-01

    A 1-5 MeV proton beamline is being built by the Turkish Atomic Energy Authority in collaboration with a number of graduate students from different universities. The primary goal of the project, is to acquire the design ability and manufacturing capability of all the components locally. SPP will be an accelerator and beam diagnostics test facility and it will also serve the detector development community with its low beam current. This paper discusses the design and construction of the RF power supply and the RF transmission line components such as its waveguide converters and its circulator. Additionally low and high power RF test results are presented to compare the performances of the locally produced components to the commercially available ones.

  11. Eighth CW and High Average Power RF Workshop

    CERN Document Server

    2014-01-01

    We are pleased to announce the next Continuous Wave and High Average RF Power Workshop, CWRF2014, to take place at Hotel NH Trieste, Trieste, Italy from 13 to 16 May, 2014. This is the eighth in the CWRF workshop series and will be hosted by Elettra - Sincrotrone Trieste S.C.p.A. (www.elettra.eu). CWRF2014 will provide an opportunity for designers and users of CW and high average power RF systems to meet and interact in a convivial environment to share experiences and ideas on applications which utilize high-power klystrons, gridded tubes, combined solid-state architectures, high-voltage power supplies, high-voltage modulators, high-power combiners, circulators, cavities, power couplers and tuners. New ideas for high-power RF system upgrades and novel ways of RF power generation and distribution will also be discussed. CWRF2014 sessions will start on Tuesday morning and will conclude on Friday lunchtime. A visit to Elettra and FERMI will be organized during the workshop. ORGANIZING COMMITTEE (OC): Al...

  12. High-power MUTC photodetectors for RF photonic links

    Science.gov (United States)

    Estrella, Steven; Johansson, Leif A.; Mashanovitch, Milan L.; Beling, Andreas

    2016-02-01

    High power photodiodes are needed for a range of applications. The high available power conversion efficiency makes these ideal for antenna remoting applications, including high power, low duty-cycle RF pulse generation. The compact footprint and fiber optic input allow densely packed RF aperture arrays with low cross-talk for phased high directionality emitters. Other applications include linear RF photonic links and other high dynamic range optical systems. Freedom Photonics has developed packaged modified uni-traveling carrier (MUTC) photodetectors for high-power applications. Both single and balanced photodetector pairs are mounted on a ceramic carrier, and packaged in a compact module optimized for high power operation. Representative results include greater than 100 mA photocurrent, >100m W generated RF power and >20 GHz bandwidth. In this paper, we evaluate the saturation and bandwidth of these single ended and balanced photodetectors for detector diameter in the 16 μm to 34 μm range. Packaged performance is compared to chip performance. Further new development towards the realization of <100GHz packaged photodetector modules with optimized high power performance is described. Finally, incorporation of these photodetector structures in novel photonic integrated circuits (PICs) for high optical power application areas is outlined.

  13. LTE modem power consumption, SAR and RF signal strength emulation

    DEFF Research Database (Denmark)

    Musiige, Deogratius; Vincent, Laulagnet; Anton, François

    2012-01-01

    This paper presents a new methodology for emulating the LTE modem power consumption, emitted SAR and RF signal strength when transmitting an LTE signal. The inputs of the methodology are: modem logical/protocol commands, time advance, near-field specifier, and antenna characteristics. The power...

  14. A 12 GHZ RF Power source for the CLIC study

    CERN Document Server

    Peauger, F; Curt, S; Doebert, S; McMonagle, G; Rossat, G; Schirm, KM; Syratchev, I; Timeo, L; Kuzikhov, S; Vikharev, AA; Haase, A; Sprehn, D; Jensen, A; Jongewaard, EN; Nantista, CD; Vlieks, A

    2010-01-01

    The CLIC RF frequency has been changed in 2008 from the initial 30 GHz to the European X-band 11.9942 GHz permitting beam independent power production using klystrons for CLIC accelerating structure testing. A design and fabrication contract for five klystrons at that frequency has been signed by different parties with SLAC. France (IRFU, CEA Saclay) is contributing a solid state modulator purchased in industry and specific 12 GHz RF network components to the CLIC study. RF pulses over 120 MW peak at 230 ns length will be obtained by using a novel SLED-I type pulse compression scheme designed and fabricated by IAP, Nizhny Novgorod, Russia. The X-band power test stand is being installed in the CLIC Test Facility CTF3 for independent structure and component testing in a bunker, but allowing, in a later stage, for powering RF components in the CTF3 beam lines. The design of the facility, results from commissioning of the RF power source and the expected performance of the Test Facility are reported.

  15. A 12 GHz RF Power Source for the CLIC Study

    Energy Technology Data Exchange (ETDEWEB)

    Schirm, Karl; /CERN; Curt, Stephane; /CERN; Dobert, Steffen; /CERN; McMonagle, Gerard; /CERN; Rossat, Ghislain; /CERN; Syratchev, Igor; /CERN; Timeo, Luca; /CERN; Haase, Andrew /SLAC; Jensen, Aaron; /SLAC; Jongewaard, Erik; /SLAC; Nantista, Christopher; /SLAC; Sprehn, Daryl; /SLAC; Vlieks, Arnold; /SLAC; Hamdi, Abdallah; /Saclay; Peauger, Franck; /Saclay; Kuzikov, Sergey; /Nizhnii Novgorod, IAP; Vikharev, Alexandr; /Nizhnii Novgorod, IAP

    2012-07-03

    The CLIC RF frequency has been changed in 2008 from the initial 30 GHz to the European X-band 11.9942 GHz permitting beam independent power production using klystrons for CLIC accelerating structure testing. A design and fabrication contract for five klystrons at that frequency has been signed by different parties with SLAC. France (IRFU, CEA Saclay) is contributing a solid state modulator purchased in industry and specific 12 GHz RF network components to the CLIC study. RF pulses over 120 MW peak at 230 ns length will be obtained by using a novel SLED-I type pulse compression scheme designed and fabricated by IAP, Nizhny Novgorod, Russia. The X-band power test stand is being installed in the CLIC Test Facility CTF3 for independent structure and component testing in a bunker, but allowing, in a later stage, for powering RF components in the CTF3 beam lines. The design of the facility, results from commissioning of the RF power source and the expected performance of the Test Facility are reported.

  16. Design and Manufacture of the RF Power Supply and RF Transmission Line for SANAEM Project Prometheus

    CERN Document Server

    Turemen, G; Unel, G; Alacakir, A

    2015-01-01

    A 1-5 MeV proton beamline is being built by the Turkish Atomic Energy Authority in collaboration with a number of graduate students from different universities. The most important aspect of the project, is to acquire the design ability and manufacturing capability of all the components locally. SPP will be an accelerator and beam diagnostics test facility and it will also serve the detector development community with its low beam current. This paper discusses the design and construction of the RF power supply and the RF transmission line components such as its waveguide converters and its circulator.

  17. High power RF test of an 805 MHz RF cavity for a muon cooling channel

    Science.gov (United States)

    Li, D.; Corlett, J.; MacGill, R.; Rimmer, R.; Wallig, J.

    2002-05-01

    We present recent high power RF test results on an 805 MHz cavity for a muon cooling experiment at Lab G in Fermilab. In order to achieve high accelerating gradient for large transverse emittance muon beams, the cavity design has adopted a pillbox like shape with 16 cm diameter beam iris covered by thin Be windows, which are demountable to allow for RF tests of different windows. The cavity body is made from copper with stiff stainless steel rings brazed to the cavity body for window attachments. View ports and RF probes are available for visual inspections of the surface of windows and cavity and measurement of the field gradient. Maximum of three thermo-couples can be attached to the windows for monitoring the temperature gradient on the windows caused by RF heating. The cavity was measured to have Q0 of about 15,000 with copper windows and coupling constant of 1.3 before final assembling. A 12 MW peak power klystron is available at Lab G in Fermilab for the high power test. The cavity and coupler designs were performed using the MAFIA code in the frequency and the time domain. Numerical simulation results and cold test measurements on the cavity and coupler will be presented for comparisons.

  18. High power RF test of an 805 MHz RF cavity for a muon cooling channel

    Energy Technology Data Exchange (ETDEWEB)

    Li, Derun; Corlett, J.; MacGill, R.; Rimmer, R.; Wallig, J.; Zisman, M.; Moretti, A.; Qian, Z.; Wu, V.; Summers, D.; Norem, J.

    2002-05-30

    We present recent high power RF test results on an 805 MHz cavity for a muon cooling experiment at Lab G in Fermilab. In order to achieve high accelerating gradient for large transverse emittance muon beams, the cavity design has adopted a pillbox like shape with 16 cm diameter beam iris covered by thin Be windows, which are demountable to allow for RF tests of different windows. The cavity body is made from copper with stiff stainless steel rings brazed to the cavity body for window attachments. View ports and RF probes are available for visual inspections of the surface of windows and cavity and measurement of the field gradient. Maximum of three thermo-couples can be attached to the windows for monitoring the temperature gradient on the windows caused by RF heating. The cavity was measured to have Q{sub 0} of about 15,000 with copper windows and coupling constant of 1.3 before final assembling. A 12 MW peak power klystron is available at Lab G in Fermilab for the high power test. The cavity and coupler designs were performed using the MAFIA code in the frequency and the time domain. Numerical simulation results and cold test measurements on the cavity and coupler will be presented for comparisons.

  19. Introduction to RF power amplifier design and simulation

    CERN Document Server

    Eroglu, Abdullah

    2015-01-01

    Introduction to RF Power Amplifier Design and Simulation fills a gap in the existing literature by providing step-by-step guidance for the design of radio frequency (RF) power amplifiers, from analytical formulation to simulation, implementation, and measurement. Featuring numerous illustrations and examples of real-world engineering applications, this book:Gives an overview of intermodulation and elaborates on the difference between linear and nonlinear amplifiersDescribes the high-frequency model and transient characteristics of metal-oxide-semiconductor field-effect transistorsDetails activ

  20. Glycol-Substitute for High Power RF Water Loads

    CERN Document Server

    Ebert, Michael

    2005-01-01

    In water loads for high power rf applications, power is dissipated directly into the coolant. Loads for frequencies below approx. 1GHz are ordinarily using an ethylene glycol-water mixture as coolant. The rf systems at DESY utilize about 100 glycol water loads with powers ranging up to 600kW. Due to the increased ecological awareness, the use of glycol is now considered to be problematic. In EU it is forbidden to discharge glycol into the waste water system. In case of cooling system leakages one has to make sure that no glycol is lost. Since it is nearly impossible to avoid any glycol loss in large rf systems, a glycol-substitute was searched for and found. The found sodium-molybdate based substitute is actually a additive for corrosion protection in water systems. Sodium-molybdate is ecologically harmless; for instance, it is also used as fertilizer in agriculture. A homoeopathic dose of 0.4% mixed into deionised water gives better rf absorption characteristics than a 30% glycol mixture. The rf coolant feat...

  1. Modeling and design techniques for RF power amplifiers

    CERN Document Server

    Raghavan, Arvind; Laskar, Joy

    2008-01-01

    The book covers RF power amplifier design, from device and modeling considerations to advanced circuit design architectures and techniques. It focuses on recent developments and advanced topics in this area, including numerous practical designs to back the theoretical considerations. It presents the challenges in designing power amplifiers in silicon and helps the reader improve the efficiency of linear power amplifiers, and design more accurate compact device models, with faster extraction routines, to create cost effective and reliable circuits.

  2. High Power Combiner/Divider Design for Dual Band RF Power Amplifiers

    OpenAIRE

    Flattery, Kyle; Amin, Shoaib; Rönnow, Daniel; Mahamat, Yaya; Eroglu, Abdullah

    2015-01-01

    Design of low loss with an enhanced thermal profile power divider/combiner for high power dual-band Radio Frequency (RF) power amplifier applications is given. The practical implementation, low loss and substrate characteristics make this type of combiner ideal for high power microwave applications.  The combiner operational frequencies are chosen to operate at 900 MHz and 2.14 GHz, which are common frequencies for concurrent dual band RF power amplifiers. The analytical results are verified ...

  3. Low power RF circuit design in standard CMOS technology

    CERN Document Server

    Alvarado, Unai; Adín, Iñigo

    2012-01-01

    Low Power Consumption is one of the critical issues in the performance of small battery-powered handheld devices. Mobile terminals feature an ever increasing number of wireless communication alternatives including GPS, Bluetooth, GSM, 3G, WiFi or DVB-H. Considering that the total power available for each terminal is limited by the relatively slow increase in battery performance expected in the near future, the need for efficient circuits is now critical. This book presents the basic techniques available to design low power RF CMOS analogue circuits. It gives circuit designers a complete guide of alternatives to optimize power consumption and explains the application of these rules in the most common RF building blocks: LNA, mixers and PLLs. It is set out using practical examples and offers a unique perspective as it targets designers working within the standard CMOS process and all the limitations inherent in these technologies.

  4. RF Power Upgrade for CEBAF at Jefferson Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Andrew Kimber,Richard Nelson

    2011-03-01

    Jefferson Laboratory (JLab) is currently upgrading the 6GeV Continuous Electron Beam Accelerator Facility (CEBAF) to 12GeV. As part of the upgrade, RF systems will be added, bringing the total from 340 to 420. Existing RF systems can provide up to 6.5 kW of CW RF at 1497 MHZ. The 80 new systems will provide increased RF power of up to 13 kW CW each. Built around a newly designed and higher efficiency 13 kW klystron developed for JLab by L-3 Communications, each new RF chain is a completely revamped system using hardware different than our present installations. This paper will discuss the main components of the new systems including the 13 kW klystron, waveguide isolator, and HV power supply using switch-mode technology. Methodology for selection of the various components and results of initial testing will also be addressed. Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.

  5. An RF (R) MS Power Detector in Standard CMOS

    NARCIS (Netherlands)

    Aa, van der F.H.J.

    2006-01-01

    This Master thesis describes the research towards the integration of RF power detectors for 3G cellular phones and base stations in CMOS technology1. It is a feasibility study with the emphasis on the identification of fundamental limitations of CMOS (particularly CMOS9) and of a number of squaring

  6. Publications of Proceedings for the RF 2005 7th Workshop on High Energy Density and High Power RF

    Energy Technology Data Exchange (ETDEWEB)

    Luhmann, Jr, N C

    2006-01-01

    The University of California, Davis hosted the High Energy Density and High Power RF 7th Workshop on High Energy Density and High Power RF in Kalamata, Greece, 13-17 June, 2005. The Proceedings cost was supported by these funds from the U.S. Department of Energy. The Proceedings was published through the American Institute of Physics.

  7. Toward High-Power Klystrons With RF Power Conversion Efficiency on the Order of 90%

    CERN Document Server

    Baikov, Andrey Yu; Syratchev, Igor

    2015-01-01

    The increase in efficiency of RF power generation for future large accelerators is considered a high priority issue. The vast majority of the existing commercial high-power RF klystrons operates in the electronic efficiency range between 40% and 55%. Only a few klystrons available on the market are capable of operating with 65% efficiency or above. In this paper, a new method to achieve 90% RF power conversion efficiency in a klystron amplifier is presented. The essential part of this method is a new bunching technique - bunching with bunch core oscillations. Computer simulations confirm that the RF production efficiency above 90% can be reached with this new bunching method. The results of a preliminary study of an L-band, 20-MW peak RF power multibeam klystron for Compact Linear Collider with the efficiency above 85% are presented.

  8. Lower Power Design for UHF RF CMOS Circuits Based on the Power Consumption Acuity

    Directory of Open Access Journals (Sweden)

    Niu Xiang-jie

    2014-01-01

    Full Text Available Excessive energy consumption of UHF tag is the bottleneck of energy saving in its wide range of applications. To address this issue, a lower power design for UHF RF CMOS circuits based on power consumption acuity is proposed in this paper. Through in-depth analysis of the static and dynamic power generation principle of UHF RF circuits in the work, the power consumption acuity can be calculated by using the correlation of circuit power and input vector. Subsequently, under the guide of this acuity, the UHF RF CMOS circuits with better energy saving can be designed. Furthermore, according to the performance indicators of EPC CIG2 UHF RFID in UHF identification, the corresponding circuit is designed and implemented. The test results show that the design of UHF RF circuit based on the acuity of power consumption can reduce 35%–40% power consumption.

  9. Photoinjector RF cavity design for high power CW FEL

    Energy Technology Data Exchange (ETDEWEB)

    Kurennoy, S. (Sergey); Schrage, D. L. (Dale L.); Wood R. L. (Richard L.); Young, L. M. (Lloyd M.); Schultheiss, T. (Thomas); Christina, V.; Rathke, J.

    2003-01-01

    The project is under way to develop a key enabling technology for highpower CW FEL: an RF photoinjector capable of producing continuous average current greater than 100 mA. The specific aim is a n-mode, normalconducting IW photoinjector, 3 nC of bunch charge, 100 mA of current (at 33.3-MHz bunch repetition rate) and emittance less than 10 mm-mad. This level of performance will enable robust 100-kW-class FEL operation with electron beam energy <100 MeV, thereby reducing the size and cost of the FEL. This design is scalable to the MW power level by increasing the electron bunch repetition rate to a higher value. The major challenges are emittance control and high heat flux within the CW 700-MHz RF cavities. Results of RF cavity design and cooling schemes are presented, including both high-velocity water and liquid-nitrogen cooling options.

  10. Systematic Approach for Design of Broadband, High Efficiency, High Power RF Amplifiers

    National Research Council Canada - National Science Library

    Mohadeskasaei, Seyed Alireza; An, Jianwei; Chen, Yueyun; Li, Zhi; Abdullahi, Sani Umar; Sun, Tie

    2017-01-01

    ...‐AB RF amplifiers with high gain flatness. It is usually difficult to simultaneously achieve a high gain flatness and high efficiency in a broadband RF power amplifier, especially in a high power design...

  11. RF coupler for high-power CW FEL photoinjector

    Energy Technology Data Exchange (ETDEWEB)

    Kurennoy, S. (Sergey); Young, L. M. (Lloyd M.)

    2003-01-01

    A high-current emittance-compensated RF photoinjector is a key enabling technology for a high-power CW FEL. The design presently under way is a 100-mA 2.5-cell {pi}-mode, 700-MHz, normal conducting demonstration CW RF photoinjector. This photoinjector will be capable of accelerating 3 nC per bunch with an emittance at the wiggler less than 10 mm-mrad. The paper presents results for the RF coupling from ridged wave guides to hte photoinjector RF cavity. The LEDA and SNS couplers inspired this 'dog-bone' design. Electromagnetic modeling of the coupler-cavity system has been performed using both 2-D and 3-D frequency-domain calculations, and a novel time-domain approach with MicroWave Studio. These simulations were used to adjust the coupling coefficient and calculate the power-loss distribution on the coupling slot. The cooling of this slot is a rather challenging thermal management project.

  12. Photoinjector RF cavity design for high power CW FEL

    Energy Technology Data Exchange (ETDEWEB)

    Kurennoy, S. (Sergey); Schrage, D. L. (Dale L.); Wood R. L. (Richard L.); Young, L. M. (Lloyd M.); Schultheiss, T. (Thomas); Christina, V.; Rathke, J. (John)

    2002-01-01

    The project is under way to develop a key enabling technology for high-power CW FEL: an RF photoinjector capable of producing continuous average current greater than 100 mA. The specific aim is a 700 MHz pi-mode, normal-conducting RF photoinjector, 3 nC of bunch charge, 100 mA of current (at 33.3-MHz bunch repetition rate) and emittance less than 10 mm-mrad. This level of performance will enable robust 100-kW-class FEL operation with electron beam energy 400 MeV, thereby reducing the size and cost of the FEL. This design is scalable to the MW power level by increasing the electron bunch repetition rate from 33.3 MHz to a higher value. The major challenges are emittance control and high heat flux within the CW 700-MHz RF cavities. Results of RF cavity design and cooling schemes are presented, including both high-velocity water and liquid nitrogen cooling options.

  13. The design of high power, external antennas for radio frequency multicusp ion sources

    Science.gov (United States)

    Welton, R. F.; Stockli, M. P.; Roseberry, R. T.; Kang, Y.; Keller, R.

    2004-05-01

    The ion source for the Spallation Neutron Source (SNS) is a radio-frequency, multicusp source designed to deliver H- beam pulses of 45 mA to the SNS accelerator, with a pulse length of 1 ms and a repetition rate of 60 Hz. In order to achieve this performance the source must operate with both high peak rf power, ˜45 kW, and high average rf power, ˜3 kW, over an operational run period of 3 weeks. The most critical source component in this respect is the plasma-immersed, porcelain coated rf antenna which can be susceptible to damage during high power operation. The DESY group has developed an external antenna configuration utilizing an Al2O3 plasma chamber which has demonstrated a very long operational period exceeding 25 000 h. Their source operates with peak rf powers comparable to the SNS source but with greatly reduced average rf powers, ˜50 W. In order to explore the applicability of this external antenna concept to high average power ion sources like the SNS source, we have performed thermal, mechanical, and electromagnetic analyses of the Al2O3 plasma chamber. This article discusses the final design which has resulted from these studies as well as estimates of the power limitations of such devices.

  14. Development of a large proton accelerator for innovative researches; development of high power RF source

    Energy Technology Data Exchange (ETDEWEB)

    Chung, K. H.; Lee, K. O.; Shin, H. M.; Chung, I. Y. [KAPRA, Seoul (Korea); Kim, D. I. [Inha University, Incheon (Korea); Noh, S. J. [Dankook University, Seoul (Korea); Ko, S. K. [Ulsan University, Ulsan (Korea); Lee, H. J. [Cheju National University, Cheju (Korea); Choi, W. H. [Korea Advanced Institute of Science and Technology, Taejeon (Korea)

    2002-05-01

    This study was performed with objective to design and develop the KOMAC proton accelerator RF system. For the development of the high power RF source for CCDTL(coupled cavity drift tube linac), the medium power RF system using the UHF klystron for broadcasting was integrated and with this RF system we obtained the basic design data, operation experience and code-validity test data. Based on the medium power RF system experimental data, the high power RF system for CCDTL was designed and its performed was analyzed. 16 refs., 64 figs., 27 tabs. (Author)

  15. The Development of the Electrically Controlled High Power RF Switch and Its Application to Active RF Pulse Compression Systems

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Jiquan [Stanford Univ., CA (United States)

    2008-12-01

    In the past decades, there has been increasing interest in pulsed high power RF sources for building high-gradient high-energy particle accelerators. Passive RF pulse compression systems have been used in many applications to match the available RF sources to the loads requiring higher RF power but a shorter pulse. Theoretically, an active RF pulse compression system has the advantage of higher efficiency and compactness over the passive system. However, the key component for such a system an element capable of switching hundreds of megawatts of RF power in a short time compared to the compressed pulse width is still an open problem. In this dissertation, we present a switch module composed of an active window based on the bulk effects in semiconductor, a circular waveguide three-port network and a movable short plane, with the capability to adjust the S-parameters before and after switching. The RF properties of the switch module were analyzed. We give the scaling laws of the multiple-element switch systems, which allow the expansion of the system to a higher power level. We present a novel overmoded design for the circular waveguide three-port network and the associated circular-to-rectangular mode-converter. We also detail the design and synthesis process of this novel mode-converter. We demonstrate an electrically controlled ultra-fast high power X-band RF active window built with PIN diodes on high resistivity silicon. The window is capable of handling multi-megawatt RF power and can switch in 2-300ns with a 1000A current driver. A low power active pulse compression experiment was carried out with the switch module and a 375ns resonant delay line, obtaining 8 times compression gain with a compression ratio of 20.

  16. SIMULATIVE ANALYSIS OF OSNR AND RECEIVED ELECTRIC RF POWER OF A ROF SYSTEM HAVING VARIABLE FIBER LENGTH, USING DIFFERENT MODULATION TECHNIQUES AND OPTICAL AMPLIFIERS

    Directory of Open Access Journals (Sweden)

    KARANBIR SINGH,

    2011-05-01

    Full Text Available In this paper, we analyzed OSNR and received electric RF power of a RoF communication system having variable fiber length, using direct and external modulation techniques and different optical amplifiers. In this work, we have compared and measured the OSNR and received optical power of the RoF system for different modulation techniques, i.e. direct and external modulation. Further, we also compared the received electric RF power for variable fiber lengths for direct and external modulation using different optical amplifiers, i.e. EDFAand SOA. We observe an increase of –11 dB (approx. in the received RF power for External modulation compared to direct modulation with EDFA.

  17. Digitally Controlled Envelope Tracking Power Supply for an RF Power Amplifier

    DEFF Research Database (Denmark)

    Jakobsen, Lars Tønnes; Andersen, Michael Andreas E.

    2007-01-01

    due to clock frequency quantization. An envelope tracking power supply for an RF Power Amplifier (RFPA) can help improve system efficiency by reducing the power consumption of the RFPA. To show the advantage of the DiSOM over traditional counter based Digital PWM modulators two designs were compared...

  18. RF power amplifier: pushing the boundaries of performance versus cost

    Science.gov (United States)

    De Souza, M. M.; Chevaux, N.; Rasheduzzaman, M.

    2012-10-01

    The Radio Frequency Power Amplifier lies at the heart of all modern day communication systems ranging from the cellular infrastructure market to broadcast, radar, medical, automotive and military to name a few. Transmission systems not only require substantial power at high frequencies, but they are also one of the most demanding of semiconductor applications on account of their requirements for efficiency and linearity, which inherently introduces a tradeoff during design. Three types of device technologies have been in typical use for RF power amplification: the VDMOS (at frequencies upto 1 GHz), the LDMOS (at frequencies upto 3.5 GHz), and more recently the Gallium Nitride HEMT, which extends the frequency range upto 5-7 GHz. As an emerging technology, GaN has huge potential, but its widespread use is still currently limited by the level of experience, absence of reliable device models and prices which are roughly (6-10 times that of silicon). This overview highlights the distinct features of the RF Power devices and touches upon the performance metrics of the above technologies (in silicon and GaN).

  19. LCLS-II high power RF system overview and progress

    Energy Technology Data Exchange (ETDEWEB)

    Yeremian, Anahid Dian

    2015-10-07

    A second X-ray free electron laser facility, LCLS-II, will be constructed at SLAC. LCLS-II is based on a 1.3 GHz, 4 GeV, continuous-wave (CW) superconducting linear accelerator, to be installed in the first kilometer of the SLAC tunnel. Multiple types of high power RF (HPRF) sources will be used to power different systems on LCLS-II. The main 1.3 GHz linac will be powered by 280 1.3 GHz, 3.8 kW solid state amplifier (SSA) sources. The normal conducting buncher in the injector will use four more SSAs identical to the linac SSAs but run at 2 kW. Two 185.7 MHz, 60 kW sources will power the photocathode dual-feed RF gun. A third harmonic linac section, included for linearizing the bunch energy spread before the first bunch compressor, will require sixteen 3.9 GHz sources at about 1 kW CW. A description and an update on all the HPRF sources of LCLS-II and their implementation is the subject of this paper.

  20. Spallation Neutron Source High Power RF Installation and Commissioning Progress

    CERN Document Server

    McCarthy, Michael P; Bradley, Joseph T; Fuja, Ray E; Gurd, Pamela; Hardek, Thomas; Kang, Yoon W; Rees, Daniel; Roybal, William; Young, Karen A

    2005-01-01

    The Spallation Neutron Source (SNS) linac will provide a 1 GeV proton beam for injection into the accumulator ring. In the normal conducting (NC) section of this linac, the Radio Frequency Quadupole (RFQ) and six drift tube linac (DTL) tanks are powered by seven 2.5 MW, 402.5 MHz klystrons and the four coupled cavity linac (CCL) cavities are powered by four 5.0 MW, 805 MHz klystrons. Eighty-one 550 kW, 805 MHz klystrons each drive a single cavity in the superconducting (SC) section of the linac. The high power radio frequency (HPRF) equipment was specified and procured by LANL and tested before delivery to ensure a smooth transition from installation to commissioning. Installation of RF equipment to support klystron operation in the 350-meter long klystron gallery started in June 2002. The final klystron was set in place in September 2004. Presently, all RF stations have been installed and high power testing has been completed. This paper reviews the progression of the installation and testing of the HPRF Sys...

  1. External costs related to power production technologies. ExternE national implementation for Denmark

    Energy Technology Data Exchange (ETDEWEB)

    Schleisner, L.; Sieverts Nielsen, P.

    1997-12-01

    The objective of the ExternE National Implementation project has been to establish a comprehensive and comparable set of data on externalities of power generation for all EU member states and Norway. The tasks include the application of the ExternE methodology to the most important fuel cycles for each country as well as to update the already existing results; to aggregate these site- and technology-specific results to more general figures. The current report covers the results of the national implementation for Denmark. Three different fuel cycles have been chosen as case studies. These are fuel cycles for an offshore wind farm and a wind farm on land, a decentralised CHP plant based on natural gas and a decentralised CHP plant based on biogas. The report covers all the details of the application of the methodology to these fuel cycles aggregation to a national level. (au) EU-JOULE 3. 59 tabs., 25 ills., 61 refs.

  2. NONLINEAR CHARACTERIZATION OF CONCURRENT DUAL-BAND RF POWER AMPLIFIERS

    Institute of Scientific and Technical Information of China (English)

    Hui Ming; Liu Taijun; Ye Yan; Zhang Haili; Shen Dongya; Li Liang

    2012-01-01

    In this paper,the synchronous concurrent dual-band RF signal is used to drive the RF Power Amplifier (PA).The nonlinear characterization of a concurrent dual-band RF PA is discussed while two band signals in the dual-band are modulated by CDMA2000 and WCDMA signals.When the two band signals in the dual-band of the PA are modulated with the same signals,it is found that the nonlinearity of the PA can be expressed by any of the two corresponding baseband data.On the other hand,when the two band signals in the dual-band of the PA are modulated with two different signals,the PA nonlinearity cannot be characterized by any of the two corresponding baseband data.In this case,its nonlinearity has to be denoted by a composite signals consisting of the two baseband signals.Consequently,the requirements for the speed of the A/D converter can be largely reduced.The experimental results with CDMA2000 and WCDMA signals demonstrate the speed of the A/D converter required is only 30 M Sample Per Second (SaPS),but it will be at least 70 M SaPS for the conventional method.

  3. High Power, Solid-State RF Generation for Plasma Heating

    Science.gov (United States)

    Prager, James; Ziemba, Timothy; Miller, Kenneth; Pierren, Chris

    2016-10-01

    Radio Frequency heating systems are rarely used by the small-scale validation platform experiments due to the high cost and complexity of these systems. Eagle Harbor Technologies (EHT), Inc. is developing an all-solid-state RF plasma heating system that uses EHT's nanosecond pulser technology in an inductive adder configuration to drive nonlinear transmission lines (NLTL). The system under development does not require the use of vacuum tube technology, is inherently lower cost, and is more robust than traditional high power RF heating schemes. The inductive adder can produce 0 to20 kV pulses into 50 Ohms with sub-10 ns rise times. The inductive adder has been used to drive NLTLs near 2 GHz with other frequencies to be tested in the future. EHT will present experimental results, including RF measurements with D-dot probes and capacitve voltage probes. During this program, EHT will test the system on Helicity Injected Torus at the University of Washington and the High Beta Tokamak at Columbia University.

  4. Effect of RF power on an Al-doped ZnO thin film deposited by RF magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong-Wook; Kim, Hong-Bae [Cheongju University, Cheongju (Korea, Republic of); Kim, Deok-Kyu [Samsung LED Co. Ltd., Suwon (Korea, Republic of)

    2011-09-15

    Transparent and conductive Al-doped ZnO thin films (thickness: 200 nm) were prepared on glass substrates via RF magnetron sputtering at room temperature by using a disk of ZnO mixed with 2-wt% Al{sub 2}O{sub 3} as a target (diameter: 3 in). We investigated the effects of RF power (20 - 100 W in steps of 20 W) on the structural, optical, and electrical properties of the fabricated thin films. The preferred orientation was observed on the (002) plane of all the Al-doped ZnO thin films deposited on the glass substrates. Moreover, good crystallinity was obtained in the RF power range of 40 - 80 W. All the Al-doped ZnO thin films exhibited more than 80% transmittance, regardless of the RF power; the optical band gap increased with the RF power. The best electrical properties were obtained at 80 W as follows: electrical resistivity = 1.76 x 10{sup -3} {Omega}cm, carrier concentration = 6.35 x 10{sup 20} cm{sup -3}, and mobility = 5.57 cm{sup 2} V{sup -1} s{sup -1}. The results of X-ray photoelectron spectroscopy (XPS) analysis showed that the number of O vacancies and Al atoms depended on the RF power and that they were maximum at 80 W.

  5. First Results with a Fast Phase and Amplitude Modulator for High Power RF Application

    CERN Document Server

    Frischholz, Hans; Valuch, D; Weil, C

    2004-01-01

    In a high energy and high power superconducting proton linac, it is more economical to drive several cavities with a single high power transmitter rather than to use one transmitter per cavity. However, this option has the disadvantage of not permitting individual control for each cavity, which potentially leads to instabilities. Provided that it can be built at a reasonable cost, a fast phase and amplitude modulator inserted into each cavity feeder line can provide the necessary control capability. A prototype of such a device has been built, based on two fast and compact high power RF phase-shifters, magnetically biased by external coils. The design is described, together with the results obtained at high and low power levels.

  6. High power RF solid state power amplifier system

    Science.gov (United States)

    Sims, III, William Herbert (Inventor); Chavers, Donald Gregory (Inventor); Richeson, James J. (Inventor)

    2011-01-01

    A high power, high frequency, solid state power amplifier system includes a plurality of input multiple port splitters for receiving a high-frequency input and for dividing the input into a plurality of outputs and a plurality of solid state amplifier units. Each amplifier unit includes a plurality of amplifiers, and each amplifier is individually connected to one of the outputs of multiport splitters and produces a corresponding amplified output. A plurality of multiport combiners combine the amplified outputs of the amplifiers of each of the amplifier units to a combined output. Automatic level control protection circuitry protects the amplifiers and maintains a substantial constant amplifier power output.

  7. Effect of rf power on the properties of rf magnetron sputtered ZnO:Al thin films

    Energy Technology Data Exchange (ETDEWEB)

    Saad, M., E-mail: pscientific@aec.org.sy [Atomic Energy Commission of Syria, P.O. Box 6091, Damascus (Syrian Arab Republic); Kassis, A. [Atomic Energy Commission of Syria, P.O. Box 6091, Damascus (Syrian Arab Republic)

    2012-09-14

    Aluminum doped zinc oxide ZnO:Al thin films were prepared using rf magnetron sputtering. The preparation was performed at room temperature and low pressure with varying rf power between P = 50 W and P = 500 W. Structural, electrical and optical film properties were studied depending on rf power. Special attention was paid to correlations among film structure, sheet resistance and optical transmission. Films with largest crystallite size exhibited highest optical transmission, but not lowest electrical resistivity. An explanation for this finding was sought in terms of the amount of Al atoms incorporated in the films and the places they occupy, parameters which are in turn related to rf power. -- Highlights: Black-Right-Pointing-Pointer Al-doped ZnO thin films were prepared by rf sputtering depending on rf power. Black-Right-Pointing-Pointer Films with largest crystallite size exhibited highest optical transmission. Black-Right-Pointing-Pointer These films did not exhibit lowest electrical resistivity! Black-Right-Pointing-Pointer Resistivity was more correlated with interplanar spacing than with crystallite size. Black-Right-Pointing-Pointer The incorporation of Al atoms and the places they occupy may explain this behavior.

  8. Progress at SLAC on high-power rf pulse compression

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, P.B.; Farkas, Z.D.; Lavine, T.L.; Menegat, A.; Nantista, C.; Ruth, R.D. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Kroll, N.M. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)]|[California Univ., San Diego, La Jolla, CA (United States). Dept. of Physics

    1992-06-01

    Rf pulse compression is a technique for augmenting the peak power output of a klystron (typically 50--100 MW) to obtain the high peak power required to drive a linear collider at a high accelerating gradient (typically 200 MW/m is required for a gradient of 100 MV/m). The SLED pulse compression system, with a power gain of about 2.6, has been operational on the SLAC linac for more than a decade. Recently, a binary pulse-compression system with a power gain of about 5.2 has been tested up to an output power of 120 MW. Further high-power tests are in progress. Our current effort is focused on prototyping a so-called SLED-II pulse-compression system with a power gain of four. Over-moded TE{sub 01}-mode circular waveguide components, some with novel technical features, are used to reduce losses at the 11.4-GHz operating frequency.

  9. Progress at SLAC on high-power rf pulse compression

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, P.B.; Farkas, Z.D.; Lavine, T.L.; Menegat, A.; Nantista, C.; Ruth, R.D. (Stanford Linear Accelerator Center, Menlo Park, CA (United States)); Kroll, N.M. (Stanford Linear Accelerator Center, Menlo Park, CA (United States) California Univ., San Diego, La Jolla, CA (United States). Dept. of Physics)

    1992-06-01

    Rf pulse compression is a technique for augmenting the peak power output of a klystron (typically 50--100 MW) to obtain the high peak power required to drive a linear collider at a high accelerating gradient (typically 200 MW/m is required for a gradient of 100 MV/m). The SLED pulse compression system, with a power gain of about 2.6, has been operational on the SLAC linac for more than a decade. Recently, a binary pulse-compression system with a power gain of about 5.2 has been tested up to an output power of 120 MW. Further high-power tests are in progress. Our current effort is focused on prototyping a so-called SLED-II pulse-compression system with a power gain of four. Over-moded TE[sub 01]-mode circular waveguide components, some with novel technical features, are used to reduce losses at the 11.4-GHz operating frequency.

  10. Development of new S-band RF window for stable high-power operation in linear accelerator RF system

    Science.gov (United States)

    Joo, Youngdo; Lee, Byung-Joon; Kim, Seung-Hwan; Kong, Hyung-Sup; Hwang, Woonha; Roh, Sungjoo; Ryu, Jiwan

    2017-09-01

    For stable high-power operation, a new RF window is developed in the S-band linear accelerator (Linac) RF systems of the Pohang Light Source-II (PLS-II) and the Pohang Accelerator Laboratory X-ray Free-Electron Laser (PAL-XFEL). The new RF window is designed to mitigate the strength of the electric field at the ceramic disk and also at the waveguide-cavity coupling structure of the conventional RF window. By replacing the pill-box type cavity in the conventional RF window with an overmoded cavity, the electric field component perpendicular to the ceramic disk that caused most of the multipacting breakdowns in the ceramic disk was reduced by an order of magnitude. The reduced electric field at the ceramic disk eliminated the Ti-N coating process on the ceramic surface in the fabrication procedure of the new RF window, preventing the incomplete coating from spoiling the RF transmission and lowering the fabrication cost. The overmoded cavity was coupled with input and output waveguides through dual side-wall coupling irises to reduce the electric field strength at the waveguide-cavity coupling structure and the possibility of mode competitions in the overmoded cavity. A prototype of the new RF window was fabricated and fully tested with the Klystron peak input power, pulse duration and pulse repetition rate of 75 MW, 4.5 μs and 10 Hz, respectively, at the high-power test stand. The first mass-produced new RF window installed in the PLS-II Linac is running in normal operation mode. No fault is reported to date. Plans are being made to install the new RF window to all S-band accelerator RF modules of the PLS-II and PAL-XFEL Linacs. This new RF window may be applied to the output windows of S-band power sources like Klystron as wells as the waveguide windows of accelerator facilities which operate in S-band.

  11. External costs related to power production technologies. ExternE national implementation for Denmark

    Energy Technology Data Exchange (ETDEWEB)

    Schleisner, L.; Sieverts Nielsen, P. [eds.

    1997-12-01

    The objective of the ExternE National Implementation project has been to establish a comprehensive and comparable set of data on externalities of power generation for all EU member states and Norway. The tasks include the application of the ExternE methodology to the most important fuel cycles for each country as well as to update the already existing results, to aggregate these site- and technology-specific results to more general figures. The current report covers the detailed information concerning the ExternE methodology. Importance is attached to the computer system used in the project and the assessment of air pollution effects on health, materials and ecological effects. Also the assessment of global warming damages are described. Finally the report covers the detailed information concerning the national implementation for Denmark for an offshore wind farm and a wind farm on land, a decentralised CHP plant based on natural gas and a decentralised CHP plant base on biogas. (au) EU-JOULE 3. 79 tabs., 11 ills., 201 refs.

  12. Neutral particle dynamics in a high-power RF source

    Energy Technology Data Exchange (ETDEWEB)

    Todorov, D., E-mail: dimitar-tdrv@phys.uni-sofia.bg; Paunska, Ts.; Shivarova, A. [Faculty of Physics, Sofia University, 5, J. Bourchier Blvd., Sofia BG-1164 (Bulgaria); Tarnev, Kh. [Department of Applied Physics, Technical University-Sofia, 8, Kl.Ohridski Blvd., Sofia BG-1000 (Bulgaria)

    2015-04-08

    Previous studies on the spatial discharge structure in the SPIDER source of negative hydrogen/deuterium ions carried out at low applied power are extended towards description of the discharge maintenance under the conditions of the actual rf power deposition of 100 kW planned for a single driver of the source. In addition to the expected higher electron density, the results show strong increase of the electron temperature and of the temperatures of the neutral species (hydrogen atoms and molecules). In the discussions, not only the spatial distribution of the plasma parameters but also that of the fluxes in the discharge (particle and energy fluxes) is involved. The obtained results come in confirmation of basic concepts for low-pressure discharge maintenance: (i) mutually related electron density and temperature as a display of the generalized Schottky condition, (ii) discharge behavior governed by the fluxes, i.e. strong nonlocality in the discharge, and (iii) a non-ambipolarity in the discharge regime, which originates from shifted maxima of the electron density and temperature and shows evidence in a vortex electron flux and in a dc current in a rf discharge, the latter resulting from a shift in the positions of the maxima of the electron density and plasma potential.

  13. RF sputtered CdS/CdTe solar cells: Effects of magnetic field, RF power, target morphology, and substrate temperature

    Energy Technology Data Exchange (ETDEWEB)

    Compaan, A.D.; Shao, M.; Tabory, C.N.; Feng, Z.; Fischer, A.; Matulionis, I.; Bohn, R.G. [Univ. of Toledo, OH (United States). Dept. of Physics and Astronomy

    1994-12-31

    In this paper the authors present a study of the influence of substrate temperature, RF power, target erosion, and magnetic field configuration on RF sputtering of CdTe and CdS. These sputtering parameters are shown to affect deposition rate, film morphology, photoluminescence efficiency, and cell performance. The magnetic field shape and strength affects the charged particle flux on the growing film and appears to have a strong influence on the final cell performance.

  14. Low power microwave tests on RF gun prototype of the Iranian Light Source Facility

    Directory of Open Access Journals (Sweden)

    A Sadeghipanah

    2017-08-01

    Full Text Available In this paper, we introduce RF electron gun of Iranian Light Source Facility (ILSF pre-injection system. Design, fabrication and low-power microwave tests results of the prototype RF electron gun have been described in detail. This paper also explains the tuning procedure of the prototype RF electron gun to the desired resonant frequency. The outcomes of this project brighten the path to the fabrication of the RF electron gun by the local industries  

  15. A describing function approach to bipolar RF-power amplifier simulation

    DEFF Research Database (Denmark)

    Vidkjær, Jens

    1981-01-01

    A method for fast and accurate computations of the primary performance parameters such as gain, efficiency, output power, and bandwidth in class-C biased RF-power amplifier stages is presented. The method is based on a describing function characterization of the RF-power transistor where the term...

  16. Outage Performance of Hybrid FSO/RF System with Low-Complexity Power Adaptation

    KAUST Repository

    Rakia, Tamer

    2016-02-26

    Hybrid free-space optical (FSO) / radio-frequency (RF) systems have emerged as a promising solution for high data- rate wireless communication systems. We consider truncated channel inversion based power adaptation strategy for coherent and non- coherent hybrid FSO/RF systems, employing an adaptive combining scheme. Specifically, we activate the RF link along with the FSO link when FSO link quality is unacceptable, and adaptively set RF transmission power to ensure constant combined signal-to-noise ratio at receiver terminal. Analytical expressions for the outage probability of the hybrid system with and without power adaptation are derived. Numerical examples show that, the hybrid FSO/RF systems with power adaptation achieve considerable outage performance improvement over conventional hybrid FSO/RF systems without power adaptation. © 2015 IEEE.

  17. Physics and technology of silicon RF power devices

    CERN Document Server

    Cao, G

    2000-01-01

    can be increased by optimising the drift and epi-layer design, higher power can be delivered without increasing the input capacitance and feedback capacitance. first time, it is identified that the intrinsic MOSFET is the dominant component in the RF LDMOSFET, which ensures the saturation property in forward I-V characteristics. Detailed results are presented on the transconductance performance of the device. It is clarified that the fall-off of transconductance of a RF LDMOSFET is caused jointly by the high resistance of this region and the reduction in channel resistance at a high gate voltage. Because of these two factors, most of the potential is dropped across the drift region at a high gate bias. As a result, the intrinsic MOSFET is forced into its linear region of operation, which results in a fall-off of the transconductance. To increase the range of gate voltages for a constant transconductance, higher drift doping concentration is preferred. This can be achieved by incorporating a grounded field pla...

  18. Swift Heavy Ion Irradiation Effects on NPN rf Power Transistors

    Science.gov (United States)

    Pushpa, N.; Prakash, A. P. Gnana; Gupta, S. K.; Revannasiddaiah, D.

    2011-07-01

    The dc characteristics of NPN rf power transistors were studied systematically before and after irradiation by 50 MeV Li3+ ions, 100 MeV F8+ ions and 140 MeV Si10+ ions in the dose range of 100 krad to 100 Mrad. The transistor parameters such as excess base current (ΔIB = IBpost-IBpre), dc current gain (hFE), and collector-saturation current (ICSat) were determined before and after irradiation. The base current (IB) was found to increase significantly after ion irradiation and this in turn decreases the hFE of the transistors. Further, the output characteristics of the irradiated devices exhibit the decrease in the collector current at the saturation region (ICSat) with increase of ion dose.

  19. CERN LINAC4 H- Source and SPL plasma generator RF systems, RF power coupling and impedance measurements

    CERN Document Server

    Paoluzzi, M; Marques-Balula, J; Nisbet, D

    2010-01-01

    In the LINAC4 H- source and the SPL plasma generator at CERN, the plasma is heated by a 100 kW, 2 MHz RF system. Matching of the load impedance to the final amplifier is achieved with a resonant network. The system implements a servo loop for power stabilization and frequency hopping to cope with the detuning effects induced by the plasma. This paper provides a detailed description of the system, including the pulse rate increase to 50 Hz for use in the SPL plasma generator. The performances, measurements of RF power coupling, contribution of the plasma to the impedance as well as first operation are reported.

  20. External Costs Related to Power Production Technologies

    DEFF Research Database (Denmark)

    Ibsen, Liselotte Schleisner; Nielsen, Per Sieverts

    1997-01-01

    The European Commission has launched a major study project, ExternE, to develop a methodology to quantify externalities. A “National Implementation Phase”, was started under the Joule II programme with the purpose of implementing the ExternE methodology in all member states. The main objective...

  1. External Costs Related to Power Production Technologies

    DEFF Research Database (Denmark)

    Ibsen, Liselotte Schleisner; Nielsen, Per Sieverts

    1997-01-01

    The European Commission has launched a major study project, ExternE, to develop a methodology to quantify externalities. A “National Implementation Phase”, was started under the Joule II programme with the purpose of implementing the ExternE methodology in all member states. The main objective of...

  2. Combining Cavity for RF Power Sources Higher Power Testing and Further Simulation

    CERN Document Server

    Wooldridge, Emma; Rogers, James H P

    2005-01-01

    A combining cavity for RF power sources has been investigated previously reported in EPAC'04 using computer simulations in CSTs' Microwave Studio© and by building a low power model out of aluminium. The model has now been tested at higher power in a number different configurations and compared with earlier results. This paper discusses the results of the higher power test and options for a combiner that can be used at the high power required for particle accelerators. It discusses further design and future modelling.

  3. Vibration Powered RF-Transponder for Sensing Low Frequency Motion Events

    Science.gov (United States)

    Gupta, S. K.; Pinrod, V.; Nadig, S.; Davaji, B.; Lal, A.

    2016-11-01

    Vibration energy harvesting offers a pathway to developing battery-less sensing solutions to be deployed in wireless sensor network nodes. The integration of the energy harvesters require regulation by power conditioning and control circuitry that consume some of the energy generated, reducing the effective energy available for node function. By designing a unique 3D-printed plastic structure for low frequency sensitivity and mechanical switching, and a lateral PZT bimorph for capturing energy from environmental vibrations, we report a zero-power consumption RF-transponder capable of detecting and reporting motion events without a battery. We have successfully picked up wireless transmissions on an external receiver placed ∼25cm away from the transponder, shaken at 0.75 g and 20 Hz. We have additionally demonstrated the ability to harvest energy from 5 Hz vibrations up to just under 150 Hz. When placed on an oil-based electric generator, which vibrates when operating, the RF-transponder has successfully picked up the differing harmonics to identify the mode of operation as the economy or regular power setting.

  4. Development of 3 kW at 325 MHz solid-state RF power amplifier using four power amplifier modules

    Science.gov (United States)

    Ramarao, B. V.; Sonal, S.; Mishra, J. K.; Pande, M.; Singh, P.; Kumar, G.; Mukherjee, J.

    2014-01-01

    A high power solid-state RF power amplifier of 3 kW at 325 MHz has been developed using only four RF power amplifier modules of 850 W power output each. The design and characterization of RF power modules have been presented. A four way Wilkinson power combiner adds the output of four power amplifier modules with a total transmission loss of less than 6%. The combined power amplifier has a power gain of 20.2 dB at 1-dB compression point, and the corresponding output power is 2.8 kW at 325 MHz. The drain efficiency of the power amplifier is 65.3% at 3 kW. All the harmonics of this amplifier are below -40 dBc. The amplifier has better characteristics like fewer numbers of active devices per kilo watt, high efficiency, high gain, and ruggedness etc for RF accelerator applications.

  5. The effect of deposition RF power on the SiC passivation layer synthesized by an RF magnetron sputtering method

    Science.gov (United States)

    Keun Seo, Jae; Ko, Ki-han; Seok Choi, Won; Park, Mungi; Hwan Lee, Jong; Yi, Jun-Sin

    2011-07-01

    In this paper, we investigated the amorphous silicon carbide (a-SiC) film as an alternative material to silicon nitride (SiN) and silicon oxide (SiO 2) for the passivation layer of solar cells. The a-SiC films were deposited on the p-type silicon (1 0 0) and glass substrates by a RF magnetron sputtering method using a-SiC (99%) target. We investigated the properties according to the deposition RF power (150, 200, 250 and 300 W). The optical properties were investigated by UV-visible spectroscopy and an ellipsometer. The performance of SiC passivation layer was investigated by carrier lifetime measurement. We could obtain the lowest refractive index of 3.22 and the carrier lifetime was the highest, 7 μs at the deposition RF power of 150 W.

  6. Mapping the MMPI-2-RF Substantive Scales Onto Internalizing, Externalizing, and Thought Dysfunction Dimensions in a Forensic Inpatient Setting.

    Science.gov (United States)

    Romero, Isabella E; Toorabally, Nasreen; Burchett, Danielle; Tarescavage, Anthony M; Glassmire, David M

    2017-01-01

    Contemporary models of psychopathology-encompassing internalizing, externalizing, and thought dysfunction factors-have gained significant support. Although research indicates the Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF; Ben-Porath & Tellegen, 2008 /2011) measures these domains of psychopathology, this study addresses extant limitations in MMPI-2-RF diagnostic validity research by examining associations between all MMPI-2-RF substantive scales and broad dichotomous indicators of internalizing, externalizing, and thought dysfunction diagnoses in a sample of 1,110 forensic inpatients. Comparing those with and without internalizing diagnoses, notable effects were observed for Negative Emotionality/Neuroticism-Revised (NEGE-r), Emotional/Internalizing Dysfunction (EID), Dysfunctional Negative Emotions (RC7), Demoralization (RCd), and several other internalizing and somatic/cognitive scales. Comparing those with and without thought dysfunction diagnoses, the largest hypothesized differences occurred for Thought Dysfunction (THD), Aberrant Experiences (RC8), and Psychoticism-Revised (PSYC-r), although unanticipated differences were observed on internalizing and interpersonal scales, likely reflecting the high prevalence of internalizing dysfunction in forensic inpatients not experiencing thought dysfunction. Comparing those with and without externalizing diagnoses, the largest effects were for Substance Abuse (SUB), Antisocial Behavior (RC4), Behavioral/Externalizing Dysfunction (BXD), Juvenile Conduct Problems (JCP), and Disconstraint-Revised (DISC-r). Multivariate models evidenced similar results. Findings support the construct validity of MMPI-2-RF scales as measures of internalizing, thought, and externalizing dysfunction.

  7. Analysis of Passive RF-DC Power Rectification and Harvesting Wireless RF Energy for Micro-watt Sensors

    Directory of Open Access Journals (Sweden)

    Antwi Nimo

    2015-04-01

    Full Text Available In this paper, analytical modeling of passive rectifying circuits and the harvesting of electromagnetic (EM power from intentionally generated as well as from ubiquitous sources are presented. The presented model is based on the linearization of rectifying circuits. The model provides an accurate method of determining the output characteristics of rectifying circuits. The model was verified with Advance Design System (ADS Harmonic balance (HB simulations and measurements. The results from the presented model were in agreement with simulations and measurements. Consequently design considerations and trade-off of radio frequency (RF harvesters are discussed. To verify the exploitation of ambient RF power sources for operation of sensors, a dual-band antenna with a size of ~λ/4 at 900MHz and a passive dual-band rectifier that is able to power a commercial Thermo-Hygrometer requiring ~1.3V and 0.5MΩ from a global system for mobile communications (GSM base station is demonstrated. The RF power delivered by the receiving dual-band antenna at a distance of about 110 m from the GSM base station ranges from -27 dBm to -50 dBm from the various GSM frequency bands. Additionally, wireless range measurements of the RF harvesters in the industrial, scientific and medical (ISM band 868MHz is presented at indoor conditions.

  8. IOT RF Power Sources for Pulsed and CW Linacs

    CERN Document Server

    Bohlen, H P

    2004-01-01

    For many years, klystrons have been the preferred RF power amplifiers for both pulsed and CW linacs at UHF and higher frequencies. Their properties have earned them that position. But in recent years in UHF terrestrial television transmitters the earlier predominant klystron has been replaced the Inductive Output Tube (IOT) because the IOT provides higher efficiency and, due to its excellent linearity, can handle the simultaneous amplification of both the vision and the sound signal. Its robustness and life expectancy equals that of a klystron, and it more than compensates its lower gain by a lower price and a smaller size. For linac operation, derivates of UHF TV IOTs, capable of up to 80 kW CW output power, are already available and operating. In L-Band, they are presently joined by recently developed 15 to 30 kW CW IOTs. HOM-IOTs are expected to extend the CW range in UHF to 1 MW and beyond. Pulsed operation of an IOT can be achieved without a high-voltage modulator. Since the beam current is grid-controll...

  9. Simulation of RF power and multi-cusp magnetic field requirement for H- ion sources

    Science.gov (United States)

    Pathak, Manish; Senecha, V. K.; Kumar, Rajnish; Ghodke, Dharmraj. V.

    2016-12-01

    A computer simulation study for multi-cusp RF based H- ion source has been carried out using energy and particle balance equation for inductively coupled uniformly dense plasma considering sheath formation near the boundary wall of the plasma chamber for RF ion source used as high current injector for 1 Gev H- Linac project for SNS applications. The average reaction rates for different reactions responsible for H- ion production and destruction have been considered in the simulation model. The RF power requirement for the caesium free H- ion source for a maximum possible H- ion beam current has been derived by evaluating the required current and RF voltage fed to the coil antenna using transformer model for Inductively Coupled Plasma (ICP). Different parameters of RF based H- ion source like excited hydrogen molecular density, H- ion density, RF voltage and current of RF antenna have been calculated through simulations in the presence and absence of multicusp magnetic field to distinctly observe the effect of multicusp field. The RF power evaluated for different H- ion current values have been compared with the experimental reported results showing reasonably good agreement considering the fact that some RF power will be reflected from the plasma medium. The results obtained have helped in understanding the optimum field strength and field free regions suitable for volume emission based H- ion sources. The compact RF ion source exhibits nearly 6 times better efficiency compare to large diameter ion source.

  10. Power Adaptation Based on Truncated Channel Inversion for Hybrid FSO/RF Transmission With Adaptive Combining

    KAUST Repository

    Rakia, Tamer

    2015-07-23

    Hybrid free-space optical (FSO)/radio-frequency (RF) systems have emerged as a promising solution for high-data-rate wireless communications. In this paper, we consider power adaptation strategies based on truncated channel inversion for the hybrid FSO/RF system employing adaptive combining. Specifically, we adaptively set the RF link transmission power when FSO link quality is unacceptable to ensure constant combined signal-to-noise ratio (SNR) at the receiver. Two adaptation strategies are proposed. One strategy depends on the received RF SNR, whereas the other one depends on the combined SNR of both links. Analytical expressions for the outage probability of the hybrid system with and without power adaptation are obtained. Numerical examples show that the hybrid FSO/RF system with power adaptation achieves a considerable outage performance improvement over the conventional system.

  11. Study on the RF power necessary to ignite plasma for the ICP test facility at HUST

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Haikun [School of Electronic Information and Communications, Huazhong University of Science and Technology, Wuhan (China); State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan (China); Li, Dong; Wang, Chenre; Li, Xiaofei; Chen, Dezhi; Liu, Kaifeng; Zhou, Chi; Pan, Ruimin [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan (China)

    2015-10-15

    An Radio-Frequency (RF) Inductively Coupled Plasma (ICP) ion source test facility has been successfully developed at Huazhong University of Science and Technology (HUST). As part of a study on hydrogen plasma, the influence of three main operation parameters on the RF power necessary to ignite plasma was investigated. At 6 Pa, the RF power necessary to ignite plasma influenced little by the filament heating current from 5 A to 9 A. The RF power necessary to ignite plasma increased rapidly with the operation pressure decreasing from 8 Pa to 4 Pa. The RF power necessary to ignite plasma decreased with the number of coil turns from 6 to 10. During the experiments, plasma was produced with the electron density of the order of 10{sup 16}m{sup -3} and the electron temperature of around 4 eV. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Evaluation of a new method of RF power coupling to acceleration cavity of charged particles accelerators

    Directory of Open Access Journals (Sweden)

    A M Poursaleh

    2017-08-01

    Full Text Available In this paper, the feasibility studty of a new method of RF power coupling to acceleration cavity of charged particles accelerator will be evaluated. In this method a slit is created around the accelerator cavity, and RF power amplifier modules is connected directly to the acceleration cavity. In fact, in this design, the cavity in addition to acting as an acceleration cavity, acts as a RF power combiner. The benefits of this method are avoiding the use of RF vacuum tubes, transmission lines, high power combiner and coupler. In this research, cylindrical and coaxial cavities were studied, and a small sample coaxial cavity is build by this method. The results of the resarch showed that compact, economical and safe RF accelerators can be achieved by the proposed method

  13. Life problems of dc and RF-excited low-power CW CO2 waveguide lasers

    Science.gov (United States)

    Hochuli, U. E.; Haldemann, P. R.

    1986-01-01

    A number of different, RF-excited 3-W CW CO2 waveguide lasers have been built. Four of these lasers, after continuously working for 15,000-30,000 h, still yield about 70 percent of their original power output. The design variations cover N2and CO-bearing gas mixtures, as well as internal- and external-capacitively coupled excitation electrodes. A similar laser survived 50,000 5-min-ON/5-min-OFF cycles without significant mirror damage. It was not possible to find suitable cold cathodes that allow the building of longitudinally dc-excited CW CO2 waveguide lasers that work for such extended periods of time.

  14. Exploring the limits of broadband excitation and inversion: II. Rf-power optimized pulses

    Science.gov (United States)

    Kobzar, Kyryl; Skinner, Thomas E.; Khaneja, Navin; Glaser, Steffen J.; Luy, Burkhard

    2008-09-01

    In [K. Kobzar, T.E. Skinner, N. Khaneja, S.J. Glaser, B. Luy, Exploring the limits of broadband excitation and inversion, J. Magn. Reson. 170 (2004) 236-243], optimal control theory was employed in a systematic study to establish physical limits for the minimum rf-amplitudes required in broadband excitation and inversion pulses. In a number of cases, however, experimental schemes are not limited by rf-amplitudes, but by the overall rf-power applied to a sample. We therefore conducted a second systematic study of excitation and inversion pulses of varying pulse durations with respect to bandwidth and rf-tolerances, but this time using a modified algorithm involving restricted rf-power. The resulting pulses display a variety of pulse shapes with highly modulated rf-amplitudes and generally show better performance than corresponding pulses with identical pulse length and rf-power, but limited rf-amplitude. A detailed description of pulse shapes and their performance is given for the so-called power-BEBOP and power-BIBOP pulses.

  15. Environmental external effects from wind power based on the EU ExternE methodology

    DEFF Research Database (Denmark)

    Ibsen, Liselotte Schleisner; Nielsen, Per Sieverts

    1998-01-01

    The European Commission has launched a major study project, ExternE, to develop a methodology to quantify externalities. A “National Implementation Phase”, was started under the Joule II programme with the purpose of implementing the ExternE methodology in all member states. The main objective...

  16. Power resource management and low-power remote wireless RF electronics

    Science.gov (United States)

    Jannson, Tomasz; Forrester, Thomas; Degrood, Kevin; Lee, Kang; Gans, Eric; Walter, Kevin

    2009-05-01

    Battery power resource management becomes a critical issue in the case of self-powered remote wireless RF electronics, where the basic parameter is time of system operation before battery recharging or battery replacement. In such cases, very often related to physical protection against antitampering (AT), proper theoretical modeling of a battery driven power supply in the context of a given digital electronic system is of utmost importance. Such modeling should include various types of batteries (primary and secondary), various self-discharge processes in different temperatures, and even energy harvesting, the latter to supply power for long-term content, low-power electronic subsystems. In this paper we analyze simple modeling of resource power management, including variations of all of these parameters and energy harvesting.

  17. ADX: a high field, high power density, advanced divertor and RF tokamak

    Science.gov (United States)

    LaBombard, B.; Marmar, E.; Irby, J.; Terry, J. L.; Vieira, R.; Wallace, G.; Whyte, D. G.; Wolfe, S.; Wukitch, S.; Baek, S.; Beck, W.; Bonoli, P.; Brunner, D.; Doody, J.; Ellis, R.; Ernst, D.; Fiore, C.; Freidberg, J. P.; Golfinopoulos, T.; Granetz, R.; Greenwald, M.; Hartwig, Z. S.; Hubbard, A.; Hughes, J. W.; Hutchinson, I. H.; Kessel, C.; Kotschenreuther, M.; Leccacorvi, R.; Lin, Y.; Lipschultz, B.; Mahajan, S.; Minervini, J.; Mumgaard, R.; Nygren, R.; Parker, R.; Poli, F.; Porkolab, M.; Reinke, M. L.; Rice, J.; Rognlien, T.; Rowan, W.; Shiraiwa, S.; Terry, D.; Theiler, C.; Titus, P.; Umansky, M.; Valanju, P.; Walk, J.; White, A.; Wilson, J. R.; Wright, G.; Zweben, S. J.

    2015-05-01

    The MIT Plasma Science and Fusion Center and collaborators are proposing a high-performance Advanced Divertor and RF tokamak eXperiment (ADX)—a tokamak specifically designed to address critical gaps in the world fusion research programme on the pathway to next-step devices: fusion nuclear science facility (FNSF), fusion pilot plant (FPP) and/or demonstration power plant (DEMO). This high-field (⩾6.5 T, 1.5 MA), high power density facility (P/S ˜ 1.5 MW m-2) will test innovative divertor ideas, including an ‘X-point target divertor’ concept, at the required performance parameters—reactor-level boundary plasma pressures, magnetic field strengths and parallel heat flux densities entering into the divertor region—while simultaneously producing high-performance core plasma conditions that are prototypical of a reactor: equilibrated and strongly coupled electrons and ions, regimes with low or no torque, and no fuelling from external heating and current drive systems. Equally important, the experimental platform will test innovative concepts for lower hybrid current drive and ion cyclotron range of frequency actuators with the unprecedented ability to deploy launch structures both on the low-magnetic-field side and the high-magnetic-field side—the latter being a location where energetic plasma-material interactions can be controlled and favourable RF wave physics leads to efficient current drive, current profile control, heating and flow drive. This triple combination—advanced divertors, advanced RF actuators, reactor-prototypical core plasma conditions—will enable ADX to explore enhanced core confinement physics, such as made possible by reversed central shear, using only the types of external drive systems that are considered viable for a fusion power plant. Such an integrated demonstration of high-performance core-divertor operation with steady-state sustainment would pave the way towards an attractive pilot plant, as envisioned in the ARC concept

  18. Dependence of nuclear spin singlet lifetimes on RF spin-locking power

    CERN Document Server

    DeVience, Stephen J; Rosen, Matthew S

    2012-01-01

    We measure the lifetime of long-lived nuclear spin singlet states as a function of the strength of the RF spin-locking field and present a simple theoretical model that agrees well with our measurements, including the low-RF-power regime. We also measure the lifetime of a long-lived coherence between singlet and triplet states that does not require a spin-locking field for preservation. Our results indicate that for many molecules, singlet states can be created using weak RF spin-locking fields: more than two orders of magnitude lower RF power than in previous studies. Our findings suggest that in many biomolecules, singlets and related states with enhanced lifetimes might be achievable in vivo with safe levels of RF power.

  19. RF electric field penetration and power deposition into nonequilibrium planar-type inductively coupled plasmas

    Institute of Scientific and Technical Information of China (English)

    Mao Ming; Wang Shuai; Dai Zhong-Ling; Wang You-Nian

    2007-01-01

    The RF electric field penetration and the power deposition into planar-type inductively coupled plasmas in lowpressure discharges have been studied by means of a self-consistent model which consists of Maxwell equations combined with the kinetic equation of electrons. The Maxwell equations are solved based on the expansion of the Fourier-Bessel series for determining the RF electric field. Numerical results show the influence of a non-Maxwellian electron energy distribution on the RF electric field penetration and the power deposition for different coil currents. Moreover, the two-dimensional spatial profiles of RF electric field and power density are also shown for different numbers of RF coil turns.

  20. Solid state RF power: The route to 1W per euro cent

    Energy Technology Data Exchange (ETDEWEB)

    Heid, Oliver [Siemens AG, Mozartstrasse 57, Erlangen (Germany)

    2013-04-19

    In most particle accelerators RF power is a decisive design constraint due to high costs and relative inflexibility of current electron beam based RF sources, i.e. Klystrons, Magnetrons, Tetrodes etc. At VHF/UHF frequencies the transition to solid state devices promises to fundamentally change the situation. Recent progress brings 1 Watt per Euro cent installed cost within reach. We present a Silicon Carbide semiconductor solution utilising the Solid State Direct Drive technology at unprecedented efficiency, power levels and power densities. The proposed solution allows retrofitting of existing RF accelerators and opens the route to novel particle accelerator concepts.

  1. Plasma characteristics in inductively and capacitively coupled hybrid source using single RF power

    Science.gov (United States)

    Kim, Kwan-Yong; Lee, Moo-Young; Kim, Tae-Woo; Kim, Ju-Ho; Chung, Chin-Wook

    2016-09-01

    Parallel combined inductively coupled plasma (ICP) and capacitively coupled plasma (CCP) using single RF generator was proposed to linear control of the plasma density with RF power. In the case of ICP, linear control of the plasma density is difficult because there is a density jump up due to E to H transition. Although the plasma density of CCP changes linearly with power, the density is lower than that of ICP due to high ion energy loss at the substrate. In our hybrid source, the single RF power generator was connected to electrode and antenna, and the variable capacitor was installed between the antenna and the power generator to control the current flowing through the antenna and the electrode. By adjusting the current ratio between the antenna and the electrode, linear characteristic of plasma density with RF power is achieved.

  2. RF power source for the compact linear collider test facility (CTF3)

    CERN Document Server

    McMonagle, G; Brown, Peter; Carron, G; Hanni, R; Mourier, J; Rossat, G; Syratchev, I V; Tanner, L; Thorndahl, L

    2004-01-01

    The CERN CTF3 facility will test and demonstrate many vital components of CLIC (Compact Linear Collider). This paper describes the pulsed RF power source at 2998.55 MHz for the drive-beam accelerator (DBA), which produces a beam with an energy of 150 MeV and a current of 3.5 Amps. Where possible, existing equipment from the LEP preinjector, especially the modulators and klystrons, is being used and upgraded to achieve this goal. A high power RF pulse compression system is used at the output of each klystron, which requires sophisticated RF phase programming on the low level side to achieve the required RF pulse. In addition to the 3 GHz system two pulsed RF sources operating at 1.5 GHz are being built. The first is a wide-band, low power, travelling wave tube (TWT) for the subharmonic buncher (SHB) system that produces a train of "phase coded" subpulses as part of the injector scheme. The second is a high power narrow band system to produce 20 MW RF power to the 1.5 GHz RF deflectors in the delay loop situate...

  3. Overview on thermal and mechanical challenges of high power RF electronic packaging

    NARCIS (Netherlands)

    Yuan, C.A.; Kregting, R.; Driel, W. van; Gielen, A.W.J.; Xiao, A.; Zhang, G.Q.

    2011-01-01

    High Power RF electronics is one of the essential parts for wireless communication, including the personal communication, broadcasting, microwave radar, etc. Moreover, high efficient high power electronics has entered the ISM market, such as the power generator of microwave oven. Power electronics r

  4. Overview on thermal and mechanical challenges of high power RF electronic packaging

    NARCIS (Netherlands)

    Yuan, C.A.; Kregting, R.; Driel, W. van; Gielen, A.W.J.; Xiao, A.; Zhang, G.Q.

    2011-01-01

    High Power RF electronics is one of the essential parts for wireless communication, including the personal communication, broadcasting, microwave radar, etc. Moreover, high efficient high power electronics has entered the ISM market, such as the power generator of microwave oven. Power electronics

  5. External effects related to biogas and wind power

    DEFF Research Database (Denmark)

    Ibsen, Liselotte Schleisner; Nielsen, Per Sieverts

    1998-01-01

    Energy produced by wind power and biogas is today more expensive than energy produced by fossil fuels. However, by including external costs related to the technologies, the renewable technologies are expected to result in social benefits compared to the conventional power technologies. The paper...... will focus on estimates of externalities related to wind and biogas energy supplies using the ExternE methodology developed in a major study launched by the European Comission. External costs are the costs imporsed on society that are not included in the market price (e.g. effects of air pollution on health...

  6. New developments in RF power and polarization measurements on the ECH System on DIII-D

    Science.gov (United States)

    Cengher, M.; Lohr, J.; Gorelov, Y.; Moeller, C. P.; Ponce, D.; Torrezan, A.

    2016-10-01

    The rf power injected at the tokamak by the electron cyclotron heating (ECH) system is measured and calibrated on a shot to shot basis for the six 110 GHz, 1 MW class gyrotrons. A new technique for ECH power measurement at the tokamak using a 4-port rf monitor was tested. Polarization scans for each system show H-plane and E-plane rf waveforms can be combined to provide a reliable calibrated power signal at the closest access point near the tokamak. Previous attempts to calibrate the power at this end were limited by the pickup of only one polarization angle at the last miter bend. Calorimetric measurements in the relevant gyrotron cooling circuits in conjunction with the 4-port RF monitors with orthomode transducers can be used to calibrate the rf power. Other alternative approaches showing proportionality with the input power like the inline power monitor and in-vessel measurements are discussed. Future plans include mode content measurements at the tokamak end of the transmission line using the 4-port RF monitors and mode sensitive directional couplers. Work supported by the US DOE under DE-FC02-04ER54698.

  7. Effect of insulating layer material on RF-induced heating for external fixation system in 1.5 T MRI system.

    Science.gov (United States)

    Liu, Yan; Kainz, Wolfgang; Qian, Songsong; Wu, Wen; Chen, Ji

    2014-09-01

    The radio frequency (RF)-induced heating is a major concern when patients with medical devices are placed inside a magnetic resonance imaging (MRI) system. In this article, numerical studies are applied to investigate the potentials of using insulated materials to reduce the RF heating for external fixation devices. It is found that by changing the dielectric constant of the insulation material, the RF-induced heating at the tips of devices can be altered. This study indicates a potential technique of developing external fixation device with low MRI RF heating.

  8. Linearization and efficiency enhancement techniques for silicon power amplifiers from RF to mmW

    CERN Document Server

    Kerhervé, Eric

    2015-01-01

    This book provides an overview of current efficiency enhancement and linearization techniques for silicon power amplifier designs. It examines the latest state of the art technologies and design techniques to address challenges for RF cellular mobile, base stations, and RF and mmW WLAN applications. Coverage includes material on current silicon (CMOS, SiGe) RF and mmW power amplifier designs, focusing on advantages and disadvantages compared with traditional GaAs implementations. With this book you will learn: The principles of linearization and efficiency improvement techniquesThe arch

  9. Determination of RF source power in WPSN using modulated backscattering

    CERN Document Server

    Sreedhar, K

    2012-01-01

    A wireless sensor network (WSN) is a wireless network consisting of spatially distributed autonomous devices using sensors to cooperatively monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants, at different locations. During RF transmission energy consumed by critically energy-constrained sensor nodes in a WSN is related to the life time system, but the life time of the system is inversely proportional to the energy consumed by sensor nodes. In that regard, modulated backscattering (MB) is a promising design choice, in which sensor nodes send their data just by switching their antenna impedance and reflecting the incident signal coming from an RF source. Hence wireless passive sensor networks (WPSN) designed to operate using MB do not have the lifetime constraints. In this we are going to investigate the system analytically. To obtain interference-free communication connectivity with the WPSN nodes number of RF sources is determined and analyzed i...

  10. Design and Implementation of a RF Powering Circuit for RFID Tags or Other Batteryless Embedded Devices

    Science.gov (United States)

    Liu, Dongsheng; Wang, Rencai; Yao, Ke; Zou, Xuecheng; Guo, Liang

    2014-01-01

    A RF powering circuit used in radio-frequency identification (RFID) tags and other batteryless embedded devices is presented in this paper. The RF powering circuit harvests energy from electromagnetic waves and converts the RF energy to a stable voltage source. Analysis of a NMOS gate-cross connected bridge rectifier is conducted to demonstrate relationship between device sizes and power conversion efficiency (PCE) of the rectifier. A rectifier with 38.54% PCE under normal working conditions is designed. Moreover, a stable voltage regulator with a temperature and voltage optimizing strategy including adoption of a combination resistor is developed, which is able to accommodate a large input range of 4 V to 12 V and be immune to temperature variations. Latch-up prevention and noise isolation methods in layout design are also presented. Designed with the HJTC 0.25 μm process, this regulator achieves 0.04 mV/°C temperature rejection ratio (TRR) and 2.5 mV/V voltage rejection ratio (VRR). The RF powering circuit is also fabricated in the HJTC 0.25 μm process. The area of the RF powering circuit is 0.23 × 0.24 mm2. The RF powering circuit is successfully integrated with ISO/IEC 15693-compatible and ISO/IEC 14443-compatible RFID tag chips. PMID:25123466

  11. Effects of rf power on chemical composition and surface roughness of glow discharge polymer films

    Science.gov (United States)

    Zhang, Ling; He, Xiaoshan; Chen, Guo; Wang, Tao; Tang, Yongjian; He, Zhibing

    2016-03-01

    The glow discharge polymer (GDP) films for laser fusion targets were successfully fabricated by plasma enhanced chemical vapor deposition (PECVD) at different radio frequency (rf) powers. The films were deposited using trans-2-butene (T2B) mixed with hydrogen as gas sources. The composition and state of plasma were diagnosed by quadrupole mass spectrometer (QMS) and Langmuir probe during the deposition process. The composition, surface morphology and roughness were investigated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and white-light interferometer (WLI), respectively. Based on these observation and analyses, the growth mechanism of defects in GDP films were studied. The results show that, at low rf power, there is a larger probability for secondary polymerization and formation of multi-carbon C-H species in the plasma. In this case, the surface of GDP film turns to be cauliflower-like. With the increase of rf power, the degree of ionization is high, the relative concentration of smaller-mass hydrocarbon species increases, while the relative concentration of larger-mass hydrocarbon species decreases. At higher rf power, the energy of smaller-mass species are high and the etching effects are strong correspondingly. The GDP film's surface roughness shows a trend of decrease firstly and then increase with the increasing rf power. At rf power of 30 W, the surface root-mean-square roughness (Rq) drops to the lowest value of 12.8 nm, and no "void" defect was observed.

  12. Powering Future Mobile Phones Through RF Energy Harvesting

    OpenAIRE

    Jolly, Ankush; Peer, Mansi; Bohara, Vivek Ashok

    2017-01-01

    In this paper we present the preliminary measurement results of harvesting radio frequency(RF) energy from the mobile phones. The aim is to revolutionize the way mobile phones are being charged and paving a way of charging the future mobile phones through RF energy harvesting. In order to measure the amount of energy that can be harvested, mobile phones from two different manufactures namely Asus and Samsung have been used. It was shown that depending on the manufacturer it is possible to har...

  13. Space-charge impedance of rf-shielding wires with external ceramic and conducting pipes

    Science.gov (United States)

    Wang, Tai-Sen F.; Kurennoy, Sergey S.; Gluckstern, Robert L.

    2001-10-01

    We studied the electrostatic field due to a charged-particle beam with uniform particle density propagating inside an rf-shielding cage (rf cage) constructed from evenly spaced conducting wires. The beam and the rf cage are surrounded by a ceramic beam pipe positioned inside a conducting pipe concentric with the beam and the rf cage. The space-charge impedances in the long wavelength regime are investigated by considering the electrostatic fields due to the longitudinal and transverse perturbations on the density of the charged-particle beam. Shielding effects due to the rf cage are discussed and simple formulas are derived for estimating the space-charge impedances. Numerical examples are given for illustration. Comparisons between analytical estimates and the results produced by the field-solver computer program MAFIA show good agreement.

  14. Development of 3 kW at 325 MHz solid-state RF power amplifier using four power amplifier modules

    Energy Technology Data Exchange (ETDEWEB)

    Ramarao, B.V., E-mail: bvram@barc.gov.in [Ion Accelerator Development Division, Bhabha Atomic Research Center, Mumbai 400085 (India); Sonal, S.; Mishra, J.K.; Pande, M.; Singh, P. [Ion Accelerator Development Division, Bhabha Atomic Research Center, Mumbai 400085 (India); Kumar, G.; Mukherjee, J. [Indian Institute of Technology, Powai, Mumbai 400076 (India)

    2014-01-21

    A high power solid-state RF power amplifier of 3 kW at 325 MHz has been developed using only four RF power amplifier modules of 850 W power output each. The design and characterization of RF power modules have been presented. A four way Wilkinson power combiner adds the output of four power amplifier modules with a total transmission loss of less than 6%. The combined power amplifier has a power gain of 20.2 dB at 1-dB compression point, and the corresponding output power is 2.8 kW at 325 MHz. The drain efficiency of the power amplifier is 65.3% at 3 kW. All the harmonics of this amplifier are below −40 dBc. The amplifier has better characteristics like fewer numbers of active devices per kilo watt, high efficiency, high gain, and ruggedness etc for RF accelerator applications. -- Highlights: • High gain power amplifier, power gain at 20 dB. • High efficiency amplifier, efficiency >65%. • Minimum number of modules per kilo watt power output. • Heat sink with modules on both side, high density.

  15. High power RF system for transverse deflecting structure XFEL TDS INJ

    Science.gov (United States)

    Volobuev, E. N.; Zavadtsev, A. A.; Zavadtsev, D. A.; Smirnov, A. J.; Sobenin, N. P.; Churanov, D. V.

    2016-09-01

    The high power RF system (HPRF) is designed for RF feeding of the transverse deflecting structure of the transverse deflecting system XFEL TDS System INJ of the European X-ray Free Electron Laser. The HPRF system includes klystron, waveguide ceramic windows, directional couplers, waveguide vacuum units, spark detector and waveguide line. Operating frequency is 2997.2 MHz. Peak input power is up to 3 MW. The HPRF system has been developed, manufactured and assembled in the XFEL Injector building. The total length of the waveguide line is 55 m from the klystron at the -5 floor to the transverse deflecting structure at the -7 floor. All designed RF parameters have been obtained experimentally at low RF power level.

  16. An RF powering system with adaptive impedance matching for individual health monitoring applications.

    Science.gov (United States)

    Zemin Liu; Yu-Pin Hsu; Hella, Mona M

    2016-08-01

    This paper presents a high-efficiency RF powering system, suitable for individual health monitoring applications. The system is composed of an antenna, an impedance matching network, and a two-stage full-wave RF-DC rectifier. A novel tuning mechanism is proposed to automatically adjust the impedance of the matching network. This mechanism can effectively improve the power efficiency of the system by 47% compared to the case without tuning. For the adaptive impedance, only a 5-bits binary weighted capacitor bank is required in the matching network. The complete system, designed in a standard 0.13μm CMOS technology, converts a -6dBm 915MHz RF signal to a 1.7V DC voltage with an output current of 85μA. The simulated maximum power efficiency of the complete RF harvester is 66%.

  17. High-Power Multimode X-Band RF Pulse Compression System for Future Linear Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Tantawi, S.G.; Nantista, C.D.; Dolgashev, V.A.; Pearson, C.; Nelson, J.; Jobe, K.; Chan, J.; Fant, K.; Frisch, J.; /SLAC; Atkinson, D.; /LLNL, Livermore

    2005-08-10

    We present a multimode X-band rf pulse compression system suitable for a TeV-scale electron-positron linear collider such as the Next Linear Collider (NLC). The NLC main linac operating frequency is 11.424 GHz. A single NLC rf unit is required to produce 400 ns pulses with 475 MW of peak power. Each rf unit should power approximately 5 m of accelerator structures. The rf unit design consists of two 75 MW klystrons and a dual-moded resonant-delay-line pulse compression system that produces a flat output pulse. The pulse compression system components are all overmoded, and most components are designed to operate with two modes. This approach allows high-power-handling capability while maintaining a compact, inexpensive system. We detail the design of this system and present experimental cold test results. We describe the design and performance of various components. The high-power testing of the system is verified using four 50 MW solenoid-focused klystrons run off a common 400 kV solid-state modulator. The system has produced 400 ns rf pulses of greater than 500 MW. We present the layout of our system, which includes a dual-moded transmission waveguide system and a dual-moded resonant line (SLED-II) pulse compression system. We also present data on the processing and operation of this system, which has set high-power records in coherent and phase controlled pulsed rf.

  18. RF power transfer efficiency of inductively coupled low pressure H2 and D2 discharges

    Science.gov (United States)

    Rauner, D.; Briefi, S.; Fantz, U.

    2017-09-01

    The RF power transfer efficiency and the relevant power absorption mechanisms of inductively heated hydrogen and deuterium plasmas are investigated in the low-pressure region between 0.25 and 10 Pa. The discharges are generated in a cylindrical vessel via a helical coil applying a frequency of 1 MHz and delivered RF powers up to 800 W. The power transfer efficiency η is quantified by a subtractive method that relies on the measurement of the delivered RF power and of the RF current through the plasma coil both with and without discharge operation. By means of optical emission spectroscopy and electrical probe measurements, the key plasma parameters are obtained. For both H2 and D2, the relative behavior of the power transfer efficiency is well comparable, which increases with increasing delivered RF power and describes a maximum at pressures between 1 and 3 Pa where more than 90 % of the provided power are absorbed by the plasma. The observed relative dependencies of η on the operational parameters are found to be well explained by an analytical approach that considers the power absorption by the plasma via evaluating the RF plasma conductivity based on the measured plasma parameters. At the parameters present, non-collisional stochastic heating of electrons has to be considered for pressures p≤slant 1 {Pa}, while collisional heating dominates at higher pressure. Molecular dissociation is found to have a significant influence on the power transfer efficiency of light molecular discharges. The direct comparison of H2 and D2 identifies the higher atomic density in deuterium to cause a systematically increased power transfer efficiency due to an increased ionization rate in the present electron temperature region.

  19. Plasma Outages in Pulsed, High-Power RF Hydrogen Ion Sources

    Science.gov (United States)

    Stockli, Martin; Han, Baoxi; Murray, Syd; Pennisi, Terry; Piller, Chip; Santana, Manuel; Welton, Robert

    2011-04-01

    Pulsed, high-power RF ion sources are needed to produce copious amounts of negative H-ions for high-power accelerators with charge-changing injection schemes. When increasing the RF power, the plasma inductance changes the RF resonance, which drifts away from the low-power resonance. When the RF circuit is tuned to maximize the (pulsed) plasma power, the (off-resonance) power at the beginning of the pulse is reduced. If the induced electric fields fall below the breakdown strength of the hydrogen gas, the plasma fails to develop. This can be avoided with a compromise tune and/or by increasing the inductance of the resonant circuit. However, the breakdown strength of the hydrogen gas increases with time due to the gradual decrease of the electron-rich plasma impurities, which causes plasma outages after weeks of reliable operation. In this paper we discuss the success of different mitigations that were tested and implemented to overcome this fundamental problem of pulsed, high-power RF hydrogen ion sources.

  20. An RF energy harvesting power management circuit for appropriate duty-cycled operation

    Science.gov (United States)

    Shirane, Atsushi; Ito, Hiroyuki; Ishihara, Noboru; Masu, Kazuya

    2015-04-01

    In this study, we present an RF energy harvesting power management unit (PMU) for battery-less wireless sensor devices (WSDs). The proposed PMU realizes a duty-cycled operation that is divided into the energy charging time and discharging time. The proposed PMU detects two types of timing, thus, the appropriate timing for the activation can be recognized. The activation of WSDs at the proper timing leads to energy efficient operation and stable wireless communication. The proposed PMU includes a hysteresis comparator (H-CMP) and an RF signal detector (RF-SD) to detect the timings. The proposed RF-SD can operate without the degradation of charge efficiency by reusing the RF energy harvester (RF-EH) and H-CMP. The PMU fabricated in a 180 nm Si CMOS demonstrated the charge operation using the RF signal at 915 MHz and the two types of timing detection with less than 124 nW in the charge phase. Furthermore, in the active phase, the PMU generates a 0.5 V regulated power supply from the charged energy.

  1. Effects of rf power on chemical composition and surface roughness of glow discharge polymer films

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ling; He, Xiaoshan; Chen, Guo; Wang, Tao; Tang, Yongjian; He, Zhibing, E-mail: hezhibing802@163.com

    2016-03-15

    Graphical abstract: - Highlights: • The growth mechanism of defects in GDP films was studied upon plasma diagnosis. • Increasing rf power enhanced the etching effects of smaller-mass species. • The “void” defect was caused by high energy hydrocarbons bombardment on the surface. • The surface roughness was only 12.76 nm, and no “void” defect was observed at 30 W. - Abstract: The glow discharge polymer (GDP) films for laser fusion targets were successfully fabricated by plasma enhanced chemical vapor deposition (PECVD) at different radio frequency (rf) powers. The films were deposited using trans-2-butene (T{sub 2}B) mixed with hydrogen as gas sources. The composition and state of plasma were diagnosed by quadrupole mass spectrometer (QMS) and Langmuir probe during the deposition process. The composition, surface morphology and roughness were investigated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and white-light interferometer (WLI), respectively. Based on these observation and analyses, the growth mechanism of defects in GDP films were studied. The results show that, at low rf power, there is a larger probability for secondary polymerization and formation of multi-carbon C-H species in the plasma. In this case, the surface of GDP film turns to be cauliflower-like. With the increase of rf power, the degree of ionization is high, the relative concentration of smaller-mass hydrocarbon species increases, while the relative concentration of larger-mass hydrocarbon species decreases. At higher rf power, the energy of smaller-mass species are high and the etching effects are strong correspondingly. The GDP film's surface roughness shows a trend of decrease firstly and then increase with the increasing rf power. At rf power of 30 W, the surface root-mean-square roughness (Rq) drops to the lowest value of 12.8 nm, and no “void” defect was observed.

  2. Traveling wave linear accelerator with RF power flow outside of accelerating cavities

    Science.gov (United States)

    Dolgashev, Valery A.

    2016-06-28

    A high power RF traveling wave accelerator structure includes a symmetric RF feed, an input matching cell coupled to the symmetric RF feed, a sequence of regular accelerating cavities coupled to the input matching cell at an input beam pipe end of the sequence, one or more waveguides parallel to and coupled to the sequence of regular accelerating cavities, an output matching cell coupled to the sequence of regular accelerating cavities at an output beam pipe end of the sequence, and output waveguide circuit or RF loads coupled to the output matching cell. Each of the regular accelerating cavities has a nose cone that cuts off field propagating into the beam pipe and therefore all power flows in a traveling wave along the structure in the waveguide.

  3. Very long pulse high-RF power test of a lower hybrid frequency antenna module

    Energy Technology Data Exchange (ETDEWEB)

    Goniche, M.; Brossaud, J.; Barral, C.; Berger-By, G.; Bibet, Ph.; Poli, S.; Rey, G.; Tonon, G. [Association Euratom-CEA, Centre d`Etudes Nucleaires de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee; Seki, M.; Obara, K. [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment] [and others

    1994-03-01

    Outgassing, induced by very long RF waves injection at high power density was studied in a module, able to be used for a lower hybrid frequency antenna. Good RF properties of the module are reported, however, resonance phenomena with strong absorption of RF power (15%) was observed at high temperature (T>400 deg C). A large outgassing data base is provided by the 75 shots cumulating 27 hours of RF injection. The comparison with previous experiments (Tore Supra and TdV prototype modules) confirm the effect of baking and results are consistent. Outgassing increases exponentially with -1/T, and a desorption model with an activation energy Ed {approx} 0.35 eV fits the data up to 400 deg C. In order to design vacuum pumping system for large lower hybrid frequency antenna, outgassing rates are given for different working temperatures. (author). 11 refs., 55 figs.

  4. Preferred external power supplies; Fuentes electricas preferentes exteriores

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Anton, L.

    2010-07-01

    In June 2008 ANAV and ENDESA DISTRIBUCION (EDE) undertook a joint study of Asco NPP Preferred External Power Supplies (PEPSs) to check the number of lines or power supplies to the 110 kV substation at Asco that met the criteria defined in the power supply regulations applicable to Asco NPP and primarily to confirm compliance with IEEE 765-2006 standard. (Author).

  5. High Power Diode Lasers with External Feedback: Overview and Prospects

    DEFF Research Database (Denmark)

    Chi, Mingjun; Petersen, Paul Michael

    2012-01-01

    In summary, different external-cavity feedback techniques to improve the spatial beam quality and narrow the linewidth of the output beam from both BALs and TDLs are presented. Broad-area diode laser system with external-cavity feedback around 800 nm can produce several Watts of output power...

  6. Assessment of Environmental External Effects in Power Generation

    DEFF Research Database (Denmark)

    Meyer, Henrik Jacob; Morthorst, Poul Erik; Ibsen, Liselotte Schleisner

    1996-01-01

    to the production of electricity based on a coal fired conventional plant. In the second case heat/power generation by means of a combined heat and power plant based on biomass-generated gas is compared to that of a combined heat and power plant fuelled by natural gas.In the report the individual externalities from...... technologies. The report compares environmental externalities in the production of energy using renewable and non-renewable energy sources, respectively. The comparison is demonstrated on two specific case studies. The first case is the production of electricity based on wind power plants compared...

  7. Review on studies for external cost of nuclear power generation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Byung Heung [Korea National University of Transportation, Chungju (Korea, Republic of); Ko, Won Il [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-12-15

    External cost is cost imposed on a third party when producing or consuming a good or service. Since the 1990s, the external costs of nuclear powered electricity production have been studied. Costs are a very important factor in policy decision and the external cost is considered for cost comparison on electricity production. As for nuclear fuel cycle, a chosen technology will determine the external cost. However, there has been little research on this issue. For this study, methods for external cost on nuclear power production have been surveyed and analyzed to develop an approach for evaluating external cost on nuclear fuel cycles. Before the Fukushima accident, external cost research had focused on damage costs during normal operation of a fuel cycle. However, accident cost becomes a major concern after the accident. Various considerations for external cost including accident cost have been used to different studies, and different methods have been applied corresponding to the considerations. In this study, the results of the evaluation were compared and analyzed to identify methodological applicability to the external cost estimation with nuclear fuel cycles.

  8. A coaxial HOM coupler for a superconducting RF cavity and its low-power measurement results

    Institute of Scientific and Technical Information of China (English)

    SUN An; TANG Ya-Zhe; ZHANG Li-Ping; LI Ying-Min; Han-Sung Kim

    2011-01-01

    A resonant buildup of beam-induced fields in a superconducting radio frequency(RF)cavity may make a beam unstable or a superconducting RF cavity quench. Higher-order mode(HOM)couplers are used for damping higher-order modes to avoid such a resonant buildup. A coaxial HOM coupler based on the TTF (TESLA Test Facility)HOM coupler has been designed for the superconducting RF cavities at the Proton Engineering Frontier Project(PEFP)in order to overcome notch frequency shift and feed-through tip melting issues. In order to confirm the HOM coupler design and finalize its structural dimensions, two prototype HOM couplers have been fabricated and tested. Low-power testing and measurement of the HOM couplers has shown that the HOM coupler has good filter properties and can fully meet the damping requirements of the PEFP low-beta superconducting RF linac.

  9. External costs of material recycling strategies for fusion power plants

    Energy Technology Data Exchange (ETDEWEB)

    Hallberg, B. E-mail: bengt.hallberg@studsvik.se; Aquilonius, K.; Lechon, Y.; Cabal, H.; Saez, R.M.; Schneider, T.; Lepicard, S.; Ward, D.; Hamacher, T.; Korhonen, R

    2003-09-01

    This paper is based on studies performed within the framework of the project Socio-Economic Research on Fusion (SERF3). Several fusion power plant designs (SEAFP Models 1-6) were compared focusing on part of the plant's life cycle: environmental impact of recycling the materials. Recycling was considered for materials replaced during normal operation, as well as materials from decommissioning of the plant. Environmental impact was assessed and expressed as external cost normalised with the total electrical energy output during plant operation. The methodology used for this study has been developed by the Commission of the European Union within the frame of the ExternE project. External costs for recycling, normalised with the energy production during plant operation, are very low compared with those for other energy sources. Results indicate that a high degree of recycling is preferable, at least when considering external costs, because external costs of manufacturing of new materials and disposal costs are higher.

  10. Development and simulation of RF components for high power millimeter wave gyrotrons

    Energy Technology Data Exchange (ETDEWEB)

    Pereyaslavets, M.; Sato, M.; Shimozuma, T.; Takita, Y.; Idei, H.; Kubo, S.; Ohkubo, K.; Hayashi, K.

    1996-11-01

    To test gyrotron RF components, efficient low-power generators for rotating high-order modes of high purity are necessary. Designs of generators for the TE{sub 15,3} mode at 84 GHz and for the TE{sub 31,8} mode at 168 GHz are presented and some preliminary test results are discussed. In addition, Toshiba gyrotron cavities at 168 GHz were analyzed for leakage of RF power in the beam tunnel. To decrease RF power leakage, the declination angle of the cut-off cavity cross section has to be decreased. A TE{sub 15,3} waveguide nonlinear uptaper is analyzed at 84 GHz as well as 168 GHz uptapers. Since the calculated conversion losses are slightly higher than designed value, an optimization of those uptapers may be required. (author)

  11. Variable power combiner for RF mode shimming in 7-T MR imaging.

    Science.gov (United States)

    Yazdanbakhsh, Pedram; Solbach, Klaus; Bitz, Andreas K

    2012-09-01

    This contribution discusses the utilization of RF power in an MRI system with RF mode shimming which enables the superposition of circularly polarized modes of a transmit RF coil array driven by a Butler matrix. Since the required power for the individual modes can vary widely, mode-shimming can result in a significant underutilization of the total available RF power. A variable power combiner (VPC) is proposed to improve the power utilization: it can be realized as a reconfiguration of the MRI transmit system by the inclusion of one additional matrix network which receives the power from all transmit amplifiers at its input ports and provides any desired (combined) power distribution at its output ports by controlling the phase and amplitude of the amplifiers' input signals. The power distribution at the output ports of the VPC is then fed into the "mode" ports of the coil array Butler matrix in order to superimpose the spatial modes at the highest achievable power utilization. The VPC configuration is compared to the standard configuration of the transmit chain of our MRI system with 8 transmit channels and 16 coils. In realistic scenarios, improved power utilization was achieved from 17% to 60% and from 14% to 55% for an elliptical phantom and a region of interest in the abdomen, respectively, and an increase of the power utilization of 1 dB for a region of interest in the upper leg. In general, it is found that the VPC allows significant improvement in power utilization when the shimming solution demands only a few modes to be energized, while the technique can yield loss in power utilization in cases with many modes required at high power level.

  12. Interplay of the influence of oxygen partial pressure and rf power on the properties of rf-magnetron-sputtered AZO thin films

    Indian Academy of Sciences (India)

    A KASSIS; M SAAD; F NOUNOU

    2017-08-01

    The complex interplay between the influence of oxygen partial pressure and that of rf power on the structural,electrical and optical properties of rf-magnetron-sputtered aluminium-doped zinc oxide, AZO, thin films is illustrated. Thedependence of film electrical resistance and interplanar spacing of film crystallites on rf power seems to be different athigher oxygen partial pressure values than at lower ones. Film preparation was performed at room temperature (withoutextra heating) and low pressure $p = 0.5$ mTorr, varying the rf power density between $P = 0.57$ and 2.83 W cm$^{−2}$ at different relative oxygen partial pressure values. An explanation of film properties has been sought in terms of changes in the chemical properties of the films due to the bombardment of the films during film formation with negative oxygen ions.

  13. Design and Implementation of RF Energy Harvesting System for Low-Power Electronic Devices

    Science.gov (United States)

    Uzun, Yunus

    2016-08-01

    Radio frequency (RF) energy harvester systems are a good alternative for energizing of low-power electronics devices. In this work, an RF energy harvester is presented to obtain energy from Global System for Mobile Communications (GSM) 900 MHz signals. The energy harvester, consisting of a two-stage Dickson voltage multiplier circuit and L-type impedance matching circuits, was designed, simulated, fabricated and tested experimentally in terms of its performance. Simulation and experimental works were carried out for various input power levels, load resistances and input frequencies. Both simulation and experimental works have been carried out for this frequency band. An efficiency of 45% is obtained from the system at 0 dBm input power level using the impedance matching circuit. This corresponds to the power of 450 μW and this value is sufficient for many low-power devices. The most important parameters affecting the efficiency of the RF energy harvester are the input power level, frequency band, impedance matching and voltage multiplier circuits, load resistance and the selection of diodes. RF energy harvester designs should be optimized in terms of these parameters.

  14. Power, muscular work, and external forces in cycling.

    Science.gov (United States)

    de Groot, G; Welbergen, E; Clijsen, L; Clarijs, J; Cabri, J; Antonis, J

    1994-01-01

    Cycling performance is affected by the interaction of a number of variables, including environment, mechanical, and human factors. Engineers have focused on the development of more efficient bicycles. Kinesiologists have examined cycling performance from a human perspective. This paper summarizes only certain aspects of human ergonomics of cycling, especially those which are important for the recent current research in our departments. Power is a key to performance of physical work. During locomotion an imaginary flow of energy takes place from the metabolism to the environment, with some efficiency. The 'useful' mechanical muscle power output might be used to perform movements and to do work against the environment. The external power is defined as the sum of joint powers, each calculated as the product of the joint (net) moment and angular velocity. This definition of external power is closely related to the mean external power as applied to exercise physiology: the sum of joint powers reflects all mechanical power which in principle can be used to fulfil a certain task. In this paper, the flow of energy for cycling is traced quantitatively as far as possible. Studies on the total lower limb can give insight into the contribution of individual muscles to external power. The muscle velocity (positive or negative) is obtained from the positions and orientations of body segments and a bar linkage model of the lower limb. The muscle activity can be measured by electromyography. In this way, positive and negative work regions in individual muscles are identified. Synergy between active agonistic/antagonistic muscle groups occurs in order to deliver external power. Maximum power is influenced by body position, geometry of the bicycle and pedalling rate. This has to be interpreted in terms of the length-tension and force-velocity-power relationships of the involved muscles. Flat road and uphill cycling at different saddle-tube angles is simulated on an ergometer. The

  15. Powering Autonomous Sensors An Integral Approach with Focus on Solar and RF Energy Harvesting

    CERN Document Server

    Penella-López, María Teresa

    2011-01-01

    Autonomous sensors transmit data and power their electronics without using cables. They can be found in e.g. wireless sensor networks (WSNs) or remote acquisition systems. Although primary batteries provide a simple design for powering autonomous sensors, they present several limitations such as limited capacity and power density, and difficulty in predicting their condition and state of charge. An alternative is to extract energy from the ambient (energy harvesting). However, the reduced dimensions of most autonomous sensors lead to a low level of available power from the energy transducer. Thus, efficient methods and circuits to manage and gather the energy are a must. An integral approach for powering autonomous sensors by considering both primary batteries and energy harvesters is presented. Two rather different forms of energy harvesting are also dealt with: optical (or solar) and radiofrequency (RF). Optical energy provides high energy density, especially outdoors, whereas RF remote powering is possibly...

  16. Imaging AOTFs with Low RF Power in Deep-UV and Mid-IR

    Science.gov (United States)

    Valle, S.; Ward, J.; Pannell, C.; Johnson, N.

    Acousto-Optic Tunable Filters (AOTFs) are commonly used for applications where high speed tuning and narrow spectral resolu- tion are required. The RF drive power for peak diffraction efficiency increases as λ2 and depends on the acousto-optic figure of merit (M2), which is material dependent. In the VIS-IR region between 450 nm and 4.5 μm tellurium dioxide (TeO2) is the common material of choice due to the high M2. At longer wavelengths (up to about 12 μm) the mercurous halides and single crystal tellurium show promise. In both cases the λ2 dependency dominates the RF power consumption and for wavelengths beyond 3.5 μm the RF power consumption is above the practical limit (>5W) for larger aperture AOTF(> 10 mm × 10 mm). In the UV range (200 nm - 400 nm) the λ2 dependency is no longer dominant and the power consumption depends mainly on the M2,however, for most materials transparent in the UV the M2 is poor and thus the drive power will again be excessive (>5W). In order to reduce the RF power requirement to reach peak diffraction efficiency, a resonant configuration in crystal quartz shows promise, especially in the UV range due to its low acoustic attenuation. We describe an AOTF operating in resonance made of crystal quartz, where the reduction of RF power consumption will be reduced by a factor between 15 and 20 compared to a conventional AOTF, thus reducing the power consumption to be within the practical limit (<5W).

  17. High-power multimode X-band rf pulse compression system for future linear colliders

    Directory of Open Access Journals (Sweden)

    Sami G. Tantawi

    2005-04-01

    Full Text Available We present a multimode X-band rf pulse compression system suitable for a TeV-scale electron-positron linear collider such as the Next Linear Collider (NLC. The NLC main linac operating frequency is 11.424 GHz. A single NLC rf unit is required to produce 400 ns pulses with 475 MW of peak power. Each rf unit should power approximately 5 m of accelerator structures. The rf unit design consists of two 75 MW klystrons and a dual-moded resonant-delay-line pulse compression system that produces a flat output pulse. The pulse compression system components are all overmoded, and most components are designed to operate with two modes. This approach allows high-power-handling capability while maintaining a compact, inexpensive system. We detail the design of this system and present experimental cold test results. We describe the design and performance of various components. The high-power testing of the system is verified using four 50 MW solenoid-focused klystrons run off a common 400 kV solid-state modulator. The system has produced 400 ns rf pulses of greater than 500 MW. We present the layout of our system, which includes a dual-moded transmission waveguide system and a dual-moded resonant line (SLED-II pulse compression system. We also present data on the processing and operation of this system, which has set high-power records in coherent and phase controlled pulsed rf.

  18. A Long-Distance RF-Powered Sensor Node with Adaptive Power Management for IoT Applications.

    Science.gov (United States)

    Pizzotti, Matteo; Perilli, Luca; Del Prete, Massimo; Fabbri, Davide; Canegallo, Roberto; Dini, Michele; Masotti, Diego; Costanzo, Alessandra; Franchi Scarselli, Eleonora; Romani, Aldo

    2017-07-28

    We present a self-sustained battery-less multi-sensor platform with RF harvesting capability down to -17 dBm and implementing a standard DASH7 wireless communication interface. The node operates at distances up to 17 m from a 2 W UHF carrier. RF power transfer allows operation when common energy scavenging sources (e.g., sun, heat, etc.) are not available, while the DASH7 communication protocol makes it fully compatible with a standard IoT infrastructure. An optimized energy-harvesting module has been designed, including a rectifying antenna (rectenna) and an integrated nano-power DC/DC converter performing maximum-power-point-tracking (MPPT). A nonlinear/electromagnetic co-design procedure is adopted to design the rectenna, which is optimized to operate at ultra-low power levels. An ultra-low power microcontroller controls on-board sensors and wireless protocol, to adapt the power consumption to the available detected power by changing wake-up policies. As a result, adaptive behavior can be observed in the designed platform, to the extent that the transmission data rate is dynamically determined by RF power. Among the novel features of the system, we highlight the use of nano-power energy harvesting, the implementation of specific hardware/software wake-up policies, optimized algorithms for best sampling rate implementation, and adaptive behavior by the node based on the power received.

  19. A Long-Distance RF-Powered Sensor Node with Adaptive Power Management for IoT Applications

    Directory of Open Access Journals (Sweden)

    Matteo Pizzotti

    2017-07-01

    Full Text Available We present a self-sustained battery-less multi-sensor platform with RF harvesting capability down to −17 dBm and implementing a standard DASH7 wireless communication interface. The node operates at distances up to 17 m from a 2 W UHF carrier. RF power transfer allows operation when common energy scavenging sources (e.g., sun, heat, etc. are not available, while the DASH7 communication protocol makes it fully compatible with a standard IoT infrastructure. An optimized energy-harvesting module has been designed, including a rectifying antenna (rectenna and an integrated nano-power DC/DC converter performing maximum-power-point-tracking (MPPT. A nonlinear/electromagnetic co-design procedure is adopted to design the rectenna, which is optimized to operate at ultra-low power levels. An ultra-low power microcontroller controls on-board sensors and wireless protocol, to adapt the power consumption to the available detected power by changing wake-up policies. As a result, adaptive behavior can be observed in the designed platform, to the extent that the transmission data rate is dynamically determined by RF power. Among the novel features of the system, we highlight the use of nano-power energy harvesting, the implementation of specific hardware/software wake-up policies, optimized algorithms for best sampling rate implementation, and adaptive behavior by the node based on the power received.

  20. CORPORATE FEED WITH DUAL SEGMENT CIRCULAR POLARIZED ARRAY RECTENNA FOR LOW POWER RF ENERGY HARVESTING

    Directory of Open Access Journals (Sweden)

    CHIA CHAO KANG

    2016-06-01

    Full Text Available This paper focuses on the investigation of the level powers that can be scavenged from the ambient environment by using corporate feed with dual segment circular polarized antenna array . It will converts the received power to direct current (DC. Being a circular polarized antenna, it has higher inductance per unit area, a good Q-factor and compact capability. The design of corporate-series feed rectenna array is to achieve a high gain antenna and maximize the RF energy received by the rectenna system at ultra low power levels. The entire structure was investigated using a combination of harmonic balance nonlinear analysis and full wave electromagnetic field analysis. The results show that 5.0 dBi gain for circular polarized antenna array can be achieved at frequency 956 MHz. When the input power of 20 dBm fed into the transmitting antenna, the maximum distance for radio frequency (RF harvesting is 5.32m. The output DC voltage for various values of incident RF power is also presented. There are noticed reasonable agreements between the simulated and measured result and the works concludes that the investigation of RF energy harvesting system was successful.

  1. An autonomous battery-less sensor module powered by piezoelectric energy harvesting with RF transmission of multiple measurement signals

    Science.gov (United States)

    Ferrari, Marco; Ferrari, Vittorio; Guizzetti, Michele; Marioli, Daniele

    2009-08-01

    An energy-autonomous battery-less sensor module is presented, entirely powered by a piezoelectric energy converter driven by mechanical vibrations from the environment. The module manages and stores the converted energy, interfaces to one or more passive sensors and periodically sends the corresponding measurement signals over a radio-frequency (RF) link. As an additional variant, the module can send a programmable identification (ID) code on the RF carrier, in order to enable module tagging and tracking by the external receiver unit. The module's general architecture is presented and the strategy used for sensor signal conditioning and transmission is illustrated. The architecture and principle have been experimentally validated on a fabricated prototype including a piezoelectric bimorph converter, two passive sensors made by a resistive-capacitive sensor pair and purposely designed electronic circuitry based on low-power off-the-shelf components. In the tested experimental conditions, the prototype features a typical time interval between measurement-and-transmission events of a few tens of seconds, with event durations of the order of tens of milliseconds, corresponding to an operation duty cycle of the order of 0.1%. Peak power consumption during transmission is of the order of 20 mW and operative range is of the order of meters in a laboratory environment. The obtained results show that the proposed approach has attractive characteristics because of the total absence of batteries and, despite the inherent intermittent operation, provides significant measurement performances in terms of achievable sensitivity and resolution.

  2. An RF Power Amplifier in a Digital CMOS Process

    DEFF Research Database (Denmark)

    Nielsen, Per Asbeck; Fallesen, Carsten

    2002-01-01

    A two stage class B power amplifier for 1.9 GHz is presented. The amplifier is fabricated in a standard digital EPI-CMOS process with low resistivity substrate. The measured output power is 29 dBm in a 50 Omega load. A design method to find the large signal parameters of the output transistor...

  3. Sublimation TiN Coating of RF Power Components

    Science.gov (United States)

    Lorkiewicz, J.; Kula, J.; Pszona, S.; Sobczak, J.; Bilinski, A.

    2008-03-01

    Titanium evaporation in a reactive atmosphere of ammonia has been chosen to deposit thin (up to 10 nm) protective surface layers containing titanium nitride and titanium oxinitrides which suppress secondary electron emission. The coating procedure, applied by the author in DESY (Hamburg) for TESLA couplers anti-multipactor protection, has been recently implemented in The Andrzej Soltan Institute for Nuclear Studies (IPJ) where a new coating device is used, equipped with a special titanium sublimation setup in a 100 1 vacuum chamber. Several arrays of cylindrical and coaxial RF coupler windows have been coated so far after optimizing the processing parameters. A check of the obtained surface layers ability to attenuate secondary electron emission has been performed; measurements of the secondary electron yield from TiN layers deposited on alumina samples were done in IPJ on as-delivered coated samples, then after vacuum bake-out and finally after additional electron bombardment of their surfaces. Also chemical composition of the surface layers has been studied using XPS in the Institute of Physical Chemistry (IChF).

  4. Experiments with an rf dusty plasma and an external plasma jet

    Science.gov (United States)

    Ticoş, C. M.

    2010-12-01

    A plasma jet produced in a coaxial plasma gun was aimed at a cloud of dust particles levitated in the sheath of a radio-frequency (rf) plasma produced between two parallel-plate electrodes. A high-speed camera with a side-view on the dust cloud was used to track the dust particles. Several cases of dust motion could be observed. When the jet was parallel with the horizontal electrodes of the rf plasma the dust particles were either pushed out of the trapping region by the plasma jet or were only perturbed from their equilibrium position, oscillating with a frequency of the order of a few kHz. In the first case the trajectory of the dust particles followed the curvature of the sheath. In the second case, when the jet was fired at a small angle with the horizontal electrodes the dust particles hit the bottom electrode and ricocheted back into the sheath. Finally, another situation was observed when the jet perturbed the rf plasma and its sheath and the whole dust crystal fell to the electrode.

  5. Assessment of environmental external effects in power generation

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, H.; Morthorst, P.E.; Schleisner, L. [Risoe National Lab. (Denmark); Meyer, N.I.; Nielsen, P.S.; Nielsen, V. [The Technical Univ. of Denmark (Denmark)

    1996-12-01

    This report summarises some of the results achieved in a project carried out in Denmark in 1994 concerning externalities. The main objective was to identify, quantify and - if possible - monetize the external effects in the production of energy, especially in relation to renewable technologies. The report compares environmental externalities in the production of energy using renewable and non-renewable energy sources, respectively. The comparison is demonstrated on two specific case studies. The first case is the production of electricity based on wind power plants compared to the production of electricity based on a coal-fired conventional plant. In the second case heat/power generation by means of a combined heat and power plant based on biomass-generated gas is compared to that of a combined heat and power plant fuelled by natural gas. In the report the individual externalities from the different ways of producing energy are identified, the stress caused by the effect is assessed, and finally the monetary value of the damage is estimated. The method is applied to the local as well as the regional and global externalities. (au) 8 tabs., 7 ills., 4 refs.

  6. Design of a new VHF RF power amplifier system for LANSCE

    Energy Technology Data Exchange (ETDEWEB)

    Lyles, John T M [Los Alamos National Laboratory

    2010-01-01

    A major upgrade is replacing much of the 40 year-old proton drift tube linac RF system with new components at the Los Alamos Neutron Science Center (LANSCE). When installed, the new system will reduce the total number of electron power tubes from twenty-four to eight in the RF powerplant. A new 200 MHz high power cavity amplifier has being developed at LANSCE. This 3.2 MW final power amplifier (FPA) uses a Thales TH628 Diacrode{reg_sign}, a state-of-the-art tetrode that eliminates the large anode modulator of the triode-based FPA that has been in use for four decades. Drive power for the FPA is provided by a new tetrode intermediate power amplifier (and a solid-state driver stage). The new system has sufficient duty-factor capability to allow LANSCE to return to 1 MW beam operation. Prototype RF power amplifiers have been designed, fabricated, and assembled, and are being tested. High voltage DC power became available through innovative re-engineering of an installed system. Details of the electrical and mechanical design of the FPA and ancillary systems are discussed.

  7. State of the Art Power Couplers for Superconducting RF Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Isidoro Campisi

    2002-08-01

    Simulations are now routinely performed that allow the prediction of electromagnetic, multipacting, thermal, and mechanical properties of couplers. From these studies, better designs have been conceived which can minimize potential problems ahead of construction. Judicious use of materials and the implementation of clean practices and of careful conditioning have gradually increased the power levels at which couplers can safely operate. Machine operation at hundreds of kilowatts has been achieved in CW at KEK and Cornell, and in a pulsed mode at the TESLA Test Facility (TTF). Test stand operations in CW at the megawatt level (Accelerator for the Production of Tritium) and in pulse mode at a peak power of 2 MW (Spallation Neutron Source, TTF version II) have been achieved. The recent progress indicates that the understanding of the behavior of fundamental power couplers is rapidly increasing and that optimal designs are being developed which will allow in the future to attain routine attainment of the megawatt power levels necessary for high-beam-power machines under construction and under study.

  8. Design of RF energy harvesting platforms for power management unit with start-up circuits

    Science.gov (United States)

    Costanzo, Alessandra; Masotti, Diego

    2013-12-01

    In this contribution we discuss an unconventional rectifier design dedicated to RF energy harvesting from ultra-low sources, such as ambient RF sources which are typically of the order of few to few tens of μW. In such conditions unsuccessful results may occur if the rectenna is directly connected to its actual load since either the minimum power or the minimum activation voltage may not be simultaneously available. For this reason a double-branch rectifier topology is considered for the power management unit (PMU), instead of traditional single-branch one. The new PMU, interposed between the rectenna and application circuits, allows the system to operate with significantly lower input power with respect to the traditional solution, while preserving efficiency during steady-state power conversion.

  9. Metode RF Filter untuk Perbaikan Kinerja Received Total Wideband Power pada Sistem UMTS

    Directory of Open Access Journals (Sweden)

    adi surya antara

    2016-06-01

    Full Text Available Cellular communication system with multiple network operators operate on a co-located area (heterogeneus network causing effect of radio frequency interference. RTWP (received total wideband power value emerges as indicator radio frequency interference on UMTS system, which is primary contribution of degraded QoS cellular communication system. RF filter butterworth circuit two half section resulted as optimal design to reach the goal compare to the other circuit section. By implemented RF filter has showed improvement indicator perform RTWP on UMTS network operator.

  10. Estimation of surface charges on dielectric materials for high power rf windows

    Energy Technology Data Exchange (ETDEWEB)

    Michizono, Shinichiro, E-mail: shinichiro.michizono@kek.jp [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Saito, Yoshio [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Suharyanto [Faculty of Engineering, Gadjah Mada University, Yogyakarta 55284 (Indonesia); Yamano, Yasushi; Kobayashi, Shinichi [Faculty of Engineering, Saitama University, Saitama 338-8570 (Japan)

    2009-11-30

    The surface discharges observed at rf windows and vacuum circuit breakers (VCBs) are one of the difficulties faced when developing high-power rf windows or compact VCBs. The surface discharge is considered to take place due to the release of the surface charges. Despite the importance of the surface charging/discharging, these phenomena have not been well evaluated. In this paper, the surface charges are estimated using the multipulse method, where electron beam irradiates a sample up to the saturation condition of surface charges. The amount of surface charges on alumina and TiN coated alumina are compared and the charging mechanism is discussed.

  11. Multisine Decomposition Algorithm for RF Power Amplifier Characterization

    DEFF Research Database (Denmark)

    Palmisano, Davide; Galasso, Andrea; Tafuri, Felice Francesco;

    2015-01-01

    This paper presents an algorithm for the generation of a multisine signal capable of accurately mimicking bandwidth and first order statistics such as the probability density function and the peak-to-average power ratio (PAPR) of an arbitrary digitally modulated signal. The implemented algorithm...... outperforms state-of-the-art multisine design procedures by proposing a solution capable of achieving an arbitrarily low PAPR error with respect to the digital signal being decomposed. This innovative step enables a fast multisine-based power amplifier characterization with results that closely match...... that obtained using the actual digital signal....

  12. Linear CMOS RF power amplifiers a complete design workflow

    CERN Document Server

    Ruiz, Hector Solar

    2013-01-01

    The work establishes the design flow for the optimization of linear CMOS power amplifiers from the first steps of the design to the final IC implementation and tests. The authors also focuses on design guidelines of the inductor's geometrical characteristics for power applications and covers their measurement and characterization. Additionally, a model is proposed which would facilitate designs in terms of transistor sizing, required inductor quality factors or minimum supply voltage. The model considers limitations that CMOS processes can impose on implementation. The book also provides diffe

  13. Continuous-wave high specific output power Ar-He-Xe laser with transverse RF excitation

    NARCIS (Netherlands)

    Udalov, Yu.B.; Peters, P.J.M.; Heeman-Ilieva, M.B.; Witteman, W.J.; Ochkin, V.N.

    1994-01-01

    A transverse RF excited gas discharge has been successfully used to produce a CW Ar-He-Xe laser. A maximum output power of 330 mW has been obtained from an experimental device with 37 cm active length and a 2.25 (DOT) 2.25 cm2 cross-section. This corresponds to a specific output power of about 175 m

  14. Time-reversal duality of high-efficiency RF power amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Reveyrand, T; Ramos, I; Popovic, Z

    2012-12-06

    The similarity between RF power amplifiers and rectifiers is discussed. It is shown that the same high-efficiency harmonically-terminated power amplifier can be operated in a dual rectifier mode. Nonlinear simulations with a GaN HEMT transistor model show the time-reversal intrinsic voltage and current waveform relationship between a class-F amplifier and rectifier. Measurements on a class-F-1 amplifier and rectifier at 2.14 GHz demonstrate over 80% efficiency in both cases.

  15. Energy Efficient and Compact RF High-Power Amplifiers

    NARCIS (Netherlands)

    Calvillo Cortés, D.A.

    2014-01-01

    The main objectives of this thesis are to improve the energy efficiency and physical form-factor of high-power amplifiers in base station applications. As such, the focus of this dissertation is placed on the outphasing amplifier concept, which can offer high-efficiency, good linearity and excellent

  16. RF Couplers for Normal-Conducting Photoinjector of High-Power CW FEL

    CERN Document Server

    Kurennoy, Sergey; Wood, Richard L; Schultheiss, T J; Rathke, John; Young, Lloyd

    2004-01-01

    A high-current emittance-compensated RF photoinjector is a key enabling technology for a high-power CW FEL. A preliminary design of a normal-conducting, 2.5-cell pi-mode, 700-MHz CW RF photoinjector that will be built for demonstration purposes, is completed. This photoinjector will be capable of accelerating a 100-mA electron beam (3 nC per bunch at 35 MHz bunch repetition rate) to 2.7 MeV while providing an emittance below 7 mm-mrad at the wiggler. More than 1 MW of RF power will be fed into the photoinjector cavity through two ridge-loaded tapered waveguides. The waveguides are coupled to the cavity by "dog-bone" irises cut in a thick wall. Due to CW operation of the photoinjector, the cooling of the coupler irises is a rather challenging thermal management project. This paper presents results of a detailed electromagnetic modeling of the coupler-cavity system, which has been performed to select the coupler design that minimizes the iris heating due to RF power loss in its walls.

  17. RF Couplers for Normal-Conducting Photoinjector of High-Power CW FEL

    Science.gov (United States)

    Kurennoy, Sergey; Schrage, Dale; Wood, Richard; Schultheiss, Tom; Rathke, John; Young, Lloyd

    2004-05-01

    A high-current emittance-compensated RF photoinjector is a key enabling technology for a high-power CW FEL. A preliminary design of a normal-conducting, 2.5-cell pi-mode, 700-MHz CW RF photoinjector that will be build for demonstration purposes, is completed. This photoinjector will be capable of accelerating a 100-mA electron beam (3 nC per bunch at 35 MHz bunch repetition rate) to 2.7 MeV while providing an emittance below 7 mm-mrad at the wiggler. More than 1 MW of RF power will be fed into the photoinjector cavity through two ridge-loaded tapered waveguides. The waveguides are coupled to the cavity by "dog-bone" irises cut in a thick wall. Due to CW operation of the photoinjector, the cooling of the coupler irises is a rather challenging thermal management project. This paper presents results of a detailed electromagnetic modeling of the coupler-cavity system, which has been performed to select the coupler design that minimizes the iris heating due to RF power loss in its walls.

  18. RF couplers for normal-conducting photoinjector of high-power CW FEL

    Energy Technology Data Exchange (ETDEWEB)

    Kurennoy, S. (Sergey)

    2004-01-01

    A high-current emittance-compensated RF photoinjector is a key enabling technology for a high-power CW FEL. A preliminary design of a normal-conducting, 2.5-cell pi-mode, 700-MHz CW RF photoinjector that will be built for demonstration purposes, is completed. This photoinjector will be capable of accelerating a 100-mA electron beam (3 nC per bunch at 35 MHz bunch repetition rate) to 2.7 MeV while providing an emittance below 7 mm-mrad at the wiggler. More than 1 MW of RF power will be fed into the photoinjector cavity through two ridge-loaded tapered waveguides. The waveguides are coupled to the cavity by 'dog-bone' irises cut in a thick wall. Due to CW operation of the photoinjector, the cooling of the coupler irises is a rather challenging thermal management project. This paper presents results of a detailed electromagnetic modeling of the coupler-cavity system, which has been performed to select the coupler design that minimizes the iris heating due to RF power loss in its walls.

  19. AZO thin film-based UV sensors: effects of RF power on the films

    Science.gov (United States)

    Akin, Nihan; Ceren Baskose, U.; Kinaci, Baris; Cakmak, Mehmet; Ozcelik, Suleyman

    2015-06-01

    Al-doped zinc oxide (AZO) thin films of thickness 150 nm were deposited on polyethylene terephthalate (PET) substrates by radio frequency (RF) magnetron sputtering method under various RF powers in the range of 25-100 W. Structural, morphological, optical and electrical properties of the films were investigated by X-ray diffractometer, atomic force microscope, UV-Vis spectrometer and Hall effect measurement system. All the obtained films had a highly preferred orientation along [002] direction of the c-axis perpendicular to the flexible PET substrate and had a high-quality surface. The energy band gap ( E g) values of the films varied in the range of 3.30-3.43 eV. The minimum resistivity of 1.84 × 10-4 Ω cm was obtained at a 50 W RF power. The small changes in the RF power had a critical important role on the structural, optical and electrical properties of the sputtered AZO thin films on flexible PET substrate. In addition, UV sensing of the fabricated AZO thin film-based sensors was explored by using current-voltage (I-V) characteristics. The sensors were sensitive in the UV region of the electromagnetic spectrum.

  20. Volterra series based predistortion for broadband RF power amplifiers with memory effects

    Institute of Scientific and Technical Information of China (English)

    Jin Zhe; Song Zhihuan; He Jiaming

    2008-01-01

    RF power amplifiers(PAs)are usually considered as memoryless devices in most existing predistortion techniques.However,in broadband communication systems,such as WCDMA,the PA memory effects are significant,and memoryless predistortion cannot linearize the PAs effectively.After analyzing the PA memory effects,a novel predistortion method based on the simplified Volterra series is proposed to linearize broadband RF PAs with memory effects.The indirect learning architecture is adopted to design the predistortion scheme and the recursive least squares algorithm with forgetting factor is applied to identify the parameters of the predistorter.Simulation results show that the proposed predistortion method can compensate the nonlinear distortion and memory effects of broadband RF PAs effectively.

  1. Quality electricity lines of external power systems electric traction DC

    Directory of Open Access Journals (Sweden)

    A.V. Petrov

    2012-08-01

    Full Text Available The results of studies that compare and analyze the numerical values of some key indicators quality electricity in the lines of the external power supply system the electric traction DC. As a supplement are additional and fundamental values of energy losses in them.

  2. Environmental Externalities Related to Power Production Technologies in Denmark

    DEFF Research Database (Denmark)

    Ibsen, Liselotte Schleisner; Nielsen, Per Sieverts

    1997-01-01

    of the Danish part of the project is to implement the framework for externality evaluation, for three different power plants located in Denmark. The paper will focus on the assessment of the impacts of the whole fuel cycles for wind, natural gas and biogas. Priority areas for environmental impact assessment...

  3. Suppressing RF breakdown of powerful backward wave oscillator by field redistribution

    Directory of Open Access Journals (Sweden)

    W. Song

    2012-03-01

    Full Text Available An over mode method for suppressing the RF breakdown on metal surface of resonant reflector cavity in powerful backward wave oscillator is investigated. It is found that the electric field is redistributed and electron emission is restrained with an over longitudinal mode cavity. Compared with the general device, a frequency band of about 5 times wider and a power capacity of at least 1.7 times greater are obtained. The results were verified in an X-band high power microwave generation experiment with the output power near 4 gigawatt.

  4. Wide-Range Adaptive RF-to-DC Power Converter for UHF RFIDs

    KAUST Repository

    Ouda, Mahmoud H.

    2016-07-27

    A wide-range, differential, cross-coupled rectifier is proposed with an extended dynamic range of input RF power that enables wireless powering from varying distances. The proposed architecture mitigates the reverse-leakage problem in conven- tional, cross-coupled rectifiers without degrading sensitivity. A prototype is designed for UHF RFID applications, and is imple- mented using 0.18 μ m CMOS technology. On-chip measurements demonstrate a sensitivity of − 18 dBm for 1 V output over a 100 k Ω load and a peak RF-to-DC power conversion efficiency of 65%. A conventional, fully cross-coupled rectifier is fabricated along- side for comparison and the proposed rectifier shows more than 2 × increase in dynamic range and a 25% boosting in output voltage than the conventional rectifier

  5. Normal-conducting RF cavity of high current photoinjector for high power CW FEL.

    Energy Technology Data Exchange (ETDEWEB)

    Kurennoy, S. (Sergey); Schrage, D. L. (Dale L.); Wood R. L. (Richard L.); Schultheiss, T. (Thomas); Rathke, J. (John); Young, L. M. (Lloyd M.)

    2004-01-01

    An RF photoinjector capable of producing high continuous average current with low emittance and energy spread is a key enabling technology for high power CW FEL. The design of a 2.5-cell, {pi}-mode, 700-MHz normal-conducting RF photoinjector cavity with magnetic emittance compensation is completed. With the electric field gradients of 7.7, and 5 MV/m in the three cells, the photoinjector will produce a 2.5-MeV electron beam with 3-nC charge per bunch and the transverse rms emittance 7 mm-mrad. Electromagnetic modeling was used extensively to optimize ridge-loaded tapered waveguides and RF couplers, which led to a new, improved coupler iris design. The results, combined with a thermal and stress analysis, show that the challenging problem of cavity cooling can be successfully solved. The manufacturing of a demo 100-mA (at 35 MHz bunch repetition rate) photoinjector is underway. The design is scalable to higher power levels by increasing the electron bunch repetition rate, and provides a path to a MW-class amplifier FEL. This paper presents the cavity design and details of RF coupler modeling.

  6. Normal conducting RF cavity of high current photoinjector for high power CW FEL.

    Energy Technology Data Exchange (ETDEWEB)

    Kurennoy, S. (Sergey); Schrage, D. L. (Dale L.); Wood R. L. (Richard L.); Schultheiss, T. (Thomas); Rathke, J. (John); Christina, V.; Young, L. M. (Lloyd M.)

    2004-01-01

    An RF photoinjector capable of producing high continuous average current with low emittance and energy spread is a key enabling technology for high power CW FEL. The design of a 2.5-cell {pi}-mode 700-MHz normal-conducting RF photoinjector cavity with magnetic emittance compensation is completed. With the electric field gradients of 7, 7, and 5 MV/m in the three cells, the photoinjector will produce a 2.5-MeV electron beam with 3-nC charge per bunch and 7 mm-mrad transverse rms emittance. Electromagnetic modeling was used extensively to optimize ridge-loaded tapered waveguides and RF couplers, which led to a new improved coupler-iris design. The results, combined with a thermal/stress analysis, show that the challenging problem of cavity cooling can be successfully solved. A demo 100-mA (at 35-MHz bunch-repetition rate) photoinjector is being manufactured. The design is scalable to higher power levels by increasing the bunch repetition rate, and provides a path to a MW-class amplifier FEL. The cavity design and details of RF coupler modeling are presented.

  7. Progress of the ELISE test facility: results of caesium operation with low RF power

    Science.gov (United States)

    Franzen, P.; Fantz, U.; Wünderlich, D.; Heinemann, B.; Riedl, R.; Kraus, W.; Fröschle, M.; Ruf, B.; Nocentini, R.; the NNBI Team

    2015-05-01

    The Max-Planck-Institut für Plasmaphysik test facility ELISE is an important intermediate step towards the in-time realization of the ITER neutral beam injection system (NBI). ELISE is equipped with a large radio-frequency (RF) driven negative hydrogen ion source (1 × 0.9 m2) of half the size of the ITER NBI source. The paper reports on the main results of the very first operation of the source with caesium, but with low RF power, both for hydrogen and deuterium, with pulse lengths of up to 500 s. The results are rather encouraging for the achievement of the required ITER NBI parameters, especially in hydrogen, where large current densities with respect to the low RF power could be achieved at a ratio of co-extracted electrons to extracted ions of 0.5-0.6 at the relevant source pressure of 0.3 Pa. The required magnetic filter field was significantly lower than expected from the experience with the prototype RF source. Similar large extracted ion currents could be achieved also in deuterium, but with larger amounts of co-extracted electrons. Here, the required ratio of co-extracted electrons to extracted ions of one could be achieved only in short pulses.

  8. Optimization of RF power absorption by optimization techniques using the lower hybrid current drive of FTU

    Energy Technology Data Exchange (ETDEWEB)

    Centioli, C. [Associazione Euratom/ENEA Sulla Fusione, Centro Ricerche Frascati, Via E. Fermi 45, CP 65, 00044 Frascati, Rome (Italy); Iannone, F. [Associazione Euratom/ENEA Sulla Fusione, Centro Ricerche Frascati, Via E. Fermi 45, CP 65, 00044 Frascati, Rome (Italy); Mazza, G. [Associazione Euratom/ENEA Sulla Fusione, Centro Ricerche Frascati, Via E. Fermi 45, CP 65, 00044 Frascati, Rome (Italy); Panella, M. [Associazione Euratom/ENEA Sulla Fusione, Centro Ricerche Frascati, Via E. Fermi 45, CP 65, 00044 Frascati, Rome (Italy); Pangione, L. [Dipartimento di Informatica, Sistemi e Produzione, Universita di Roma, Tor Vergata, Via del Politecnico 1, 00133 Rome (Italy)]. E-mail: pangione@frascati.enea.it; Podda, S. [Associazione Euratom/ENEA Sulla Fusione, Centro Ricerche Frascati, Via E. Fermi 45, CP 65, 00044 Frascati, Rome (Italy); Tuccillo, A. [Associazione Euratom/ENEA Sulla Fusione, Centro Ricerche Frascati, Via E. Fermi 45, CP 65, 00044 Frascati, Rome (Italy); Vitale, V. [Associazione Euratom/ENEA Sulla Fusione, Centro Ricerche Frascati, Via E. Fermi 45, CP 65, 00044 Frascati, Rome (Italy); Zaccarian, L. [Dipartimento di Informatica, Sistemi e Produzione, Universita di Roma, Tor Vergata, Via del Politecnico 1, 00133 Rome (Italy)

    2005-11-15

    In this paper, we will report on the experimental results arising from the implementation of optimization techniques to maximize the RF power coupling versus the plasma conditions in the FTU experimental facility. These experiments are carried out by employing the open-source Linux-RTAI control system currently running on the FTU digital feedback loop. The RF power source under consideration is a lower hybrid system (LH) based on six gyrotrons with a nominal power output capability of 1.1 MW each. The optimization of the coupling level between the plasma and the emitting antenna reduces the reflected power, thus maximizing the heating effects in addition to avoiding danger to the emitter (equivalently, annoying safety shutdowns of the system). To this aim, the plasma displacement is modified by suitably adjusting the reference input to the stabilizing feedback, according to a steepest descent algorithm. It will be shown in the paper how this algorithm achieves a satisfactory level of robustness with respect to measurement errors and well performs both in simulation and in experimental tests, thus leading to an improved effectiveness of the RF heating system.

  9. Rectifier Design Challenges for RF Wireless Power Transfer and Energy Harvesting Systems

    Directory of Open Access Journals (Sweden)

    A. Collado

    2017-06-01

    Full Text Available The design of wireless power transfer (WPT and energy harvesting (EH solutions poses different challenges towards achieving maximum RF-DC conversion efficiency in these systems. This paper covers several selected challenges when developing WPT and electromagnetic EH solutions, such as the design of multiband and broadband rectifiers, the minimization of the effect that load and input power variations may have on the system performance and finally the most optimum power combining mechanisms that can be used when dealing with multi-element rectifiers.

  10. Reliability studies on NPN RF power transistors under swift heavy ion irradiation

    Science.gov (United States)

    Pushpa, N.; Praveen, K. C.; Gnana Prakash, A. P.; Naik, P. S.; Cressler, John D.; Gupta, S. K.; Revannasiddaiah, D.

    2012-02-01

    NPN RF power transistors were irradiated with 140 MeV Si 10+ ions, 100 MeV F 8+ ions, 50 MeV Li 3+ ions and Co-60 gamma radiation in the dose range from 100 krad to 100 Mrad. The transistor characteristics are studied before and after irradiation from which the parameters such as Gummel characteristics, excess base current (Δ IB = IBpost - IBpre), dc current gain ( hFE), transconductance ( gm) and collector-saturation current ( ICSat) are determined. The degradation observed in the electrical characteristics is almost the same for different types of ion irradiated NPN RF power transistors with similar total doses although there is a large difference in the linear energy transfer (LET) of the ions. Further, it was observed more degradation in DC I- V characteristics of ion irradiated devices than the Co-60 gamma irradiated devices for higher doses.

  11. Wavelet network based predistortion method for wideband RF power amplifiers exhibiting memory effects

    Institute of Scientific and Technical Information of China (English)

    JIN Zhe; SONG Zhi-huan; HE Jia-ming

    2007-01-01

    RF power amplifiers (PAs) are usually considered as memoryless devices in most existing predistortion techniques.Nevertheless, in wideband communication systems, PA memory effects can no longer be ignored and memoryless predistortion cannot linearize PAs effectively. After analyzing PA memory effects, a novel predistortion method based on wavelet networks (WNs) is proposed to linearize wideband RF power amplifiers. A complex wavelet network with tapped delay lines is applied to construct the predistorter and then a complex backpropagation algorithm is developed to train the predistorter parameters. The simulation results show that compared with the previously published feed-forward neural network predistortion method, the proposed method provides faster convergence rate and better performance in reducing out-of-band spectral regrowth.

  12. Electron beam gun with kinematic coupling for high power RF vacuum devices

    Energy Technology Data Exchange (ETDEWEB)

    Borchard, Philipp

    2016-11-22

    An electron beam gun for a high power RF vacuum device has components joined by a fixed kinematic coupling to provide both precise alignment and high voltage electrical insulation of the components. The kinematic coupling has high strength ceramic elements directly bonded to one or more non-ductile rigid metal components using a high temperature active metal brazing alloy. The ceramic elements have a convex surface that mates with concave grooves in another one of the components. The kinematic coupling, for example, may join a cathode assembly and/or a beam shaping focus electrode to a gun stem, which is preferably composed of ceramic. The electron beam gun may be part of a high power RF vacuum device such as, for example, a gyrotron, klystron, or magnetron.

  13. Electron beam gun with kinematic coupling for high power RF vacuum devices

    Science.gov (United States)

    Borchard, Philipp

    2016-11-22

    An electron beam gun for a high power RF vacuum device has components joined by a fixed kinematic coupling to provide both precise alignment and high voltage electrical insulation of the components. The kinematic coupling has high strength ceramic elements directly bonded to one or more non-ductile rigid metal components using a high temperature active metal brazing alloy. The ceramic elements have a convex surface that mates with concave grooves in another one of the components. The kinematic coupling, for example, may join a cathode assembly and/or a beam shaping focus electrode to a gun stem, which is preferably composed of ceramic. The electron beam gun may be part of a high power RF vacuum device such as, for example, a gyrotron, klystron, or magnetron.

  14. High voltage power supplies for ITER RF heating and current drive systems

    Energy Technology Data Exchange (ETDEWEB)

    Gassmann, T., E-mail: thibault.gassmann@iter.org [ITER Organization, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Arambhadiya, B.; Beaumont, B. [ITER Organization, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Baruah, U.K. [Institute for Plasma Research, Near Indira Bridge, Bhat, Gandhinagar 382428 (India); Bonicelli, T. [Fusion For Energy, C/3 Josep Pla 2, Torres Diagonal Litoral-B3, E-08019 Barcelona (Spain); Darbos, C.; Purohit, D.; Decamps, H. [ITER Organization, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Albajar, F. [Fusion For Energy, C/3 Josep Pla 2, Torres Diagonal Litoral-B3, E-08019 Barcelona (Spain); Gandini, F.; Henderson, M.; Kazarian, F.; Lamalle, P.U.; Omori, T. [ITER Organization, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Parmar, D.; Patel, A. [Institute for Plasma Research, Near Indira Bridge, Bhat, Gandhinagar 382428 (India); Rathi, D. [ITER Organization, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Singh, N.P. [Institute for Plasma Research, Near Indira Bridge, Bhat, Gandhinagar 382428 (India)

    2011-10-15

    The RF heating and current drive (H and CD) systems to be installed for the ITER fusion machine are the electron cyclotron (EC), ion cyclotron (IC) and, although not in the first phase of the project, lower hybrid (LH). These systems require high voltage, high current power supplies (HVPS) in CW operation. These HVPS should deliver around 50 MW electrical power to each of the RF H and CD systems with stringent requirements in terms of accuracy, voltage ripple, response time, turn off time and fault energy. The PSM (Pulse Step Modulation) technology has demonstrated over the past 20 years its ability to fulfill these requirements in many industrial facilities and other fusion reactors and has therefore been chosen as reference design for the IC and EC HVPS systems. This paper describes the technical specifications, including interfaces, the resulting constraints on the design, the conceptual design proposed for ITER EC and IC HVPS systems and the current status.

  15. High total dose proton irradiation effects on silicon NPN rf power transistors

    Science.gov (United States)

    Bharathi, M. N.; Praveen, K. C.; Pushpa, N.; Prakash, A. P. Gnana

    2014-04-01

    The effects of 3 MeV proton irradiation on the I-V characteristics of NPN rf power transistors were studied in the dose range of 100 Krad to 100 Mrad. The different electrical characteristics like Gummel, current gain and output characteristics were systematically studied before and after irradiation. The recovery in the I-V characteristics of irradiated NPN BJTs were studied by isochronal and isothermal annealing methods.

  16. High RF power test of a CFC antenna module for lower hybrid current drive

    Energy Technology Data Exchange (ETDEWEB)

    Maebara, S.; Seki, M.; Ikeda, Y.; Kiyono, K.; Suganuma, K.; Imai, T. [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Goniche, M.; Bibet, Ph.; Brossaud, J.; Cano, V.; Kazarian-Vibert, F.; Froissard, P.; Rey, G. [Association Euratom-CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

    1998-07-01

    A mock-up of a 3.7 GHz Lower Hybrid Current Drive (LHCD) antenna module was fabricated from Carbon Fibre Composite (CFC) for the development of heat resistive low Z front facing the plasma. This 2 divided waveguide module is made from CFC plates and rods which are Cu-plated to reduce the RF losses. The withstand-voltage, the RF properties and the outgassing rates for long pulses and high RF power were tested at the Lower Hybrid test bed facility of Cadarache. A reference module made from Dispersion Strengthened Copper (DSC) was also fabricated. After the short pulse conditioning, long pulses with a power density ranging between 50 and 150 MW/m{sup 2} were performed with no breakdowns on the CFC module. It was also checked that the highest power density, up to 150 MW/m{sup 2}, could be transmitted when the waveguides are filled with H2 at a pressure of 5 x 10{sup -2} Pa. During a long pulse, the power reflection coefficient remains low in the 0.8-1.3 % range and no significant change in the reflection coefficient is measured after the thermal cycling provided by the long pulse operation. From thermocouple measurements, RF losses of the copper coated CFC and the DSC modules were compared. No significant differences were measured. From pressure measurements, it was found that the outgassing rate of Cu-plated CFC is about 6-7 times larger than of DSC at 300 deg.C. It is concluded that a CFC module is an attractive candidate for the hardening of the tip of the LHCD antenna. (author)

  17. Environmental external effects for wind power and coal

    Energy Technology Data Exchange (ETDEWEB)

    Schleisner, L.; Meyer, H.J.; Morthorst, P.E. [Risoe National Lab., Roskilde (Denmark). Systems Analysis Dept.

    1995-12-31

    This article summarises some of the results achieved in a project carried out in Denmark with the purpose to assess the environmental damages and the external costs in the production of energy. The project has especially handled renewable energy versus energy based on fossil fuels. The project has been a collaboration between the Technical University of Denmark and Riso National Laboratory. The research institutions have considered different energy production technologies in the project. The energy production technologies that have been considered by Risoe National Laboratory and will be reported and compared in this article are the following: (1) Wind power, (2) A coal-fired condensing plant. In the project the environmental damages are thus compared, and externalities in the production of energy using renewable energy and fossil fuels are identified, estimated and monetized. The following result applies in general to the applied technologies. Only the environmental externalities have been assessed in the project. Social and economical externalities, e.g. related to changes in employment or depletion of resources, are not included in the project. The cost concept is based on marginal damage cost, in principle taking as starting point the level of pollution that exists today. The methodology, which has been used in order to find and monetize the environmental externalities, consists of the different processes like Identification, quantification, Dose-response and Valuation

  18. Design and fabrication of the high-power RF transmission line into the PEFP linac tunnel

    Science.gov (United States)

    Seol, Kyung-Tae; Kwon, Hyeok-Jung; Kim, Han-Sung; Cho, Yong-Sub

    2012-07-01

    The 100-MeV proton linear accelerator (linac) for the Proton Engineering Frontier Project (PEFP) has been developed and will be installed at the Gyeong-ju site. For the linac, a total of 11 sets of RF systems are required, and the waveguide layout was fixed to install high-power RF (HPRF) systems. One of the important interfaces with the building construction is the high-power radio-frequency (HPRF) transmission line embedded in the tunnel, which is used to transmit 1-MW RF power to each cavity in the tunnel. The waveguide section penetrating into the linac tunnel was designed with a bending structure for radiation shielding, and the dependence of its voltage standing-wave ratio (VSWR) on the chamfer length of the bending was calculated. The HPRF transmission line was fabricated into a piece of waveguide to prevent moisture and any foreign debris inside the 2.5-m thick concrete block. Air leakage was checked with a pressure of 0.25 psig of nitrogen gas, and a maximum VSWR of 1.196 was obtained by measuring the vector reflection coefficients with the quarter-wave transmission section. In this paper, the design and the fabrication of the HPRF transmission line into the PEFP linac tunnel are presented.

  19. An ultra-low-power RF transceiver for WBANs in medical applications

    Science.gov (United States)

    Qi, Zhang; Xiaofei, Kuang; Nanjian, Wu

    2011-06-01

    A 2.4 GHz ultra-low-power RF transceiver with a 900 MHz auxiliary wake-up link for wireless body area networks (WBANs) in medical applications is presented. The RF transceiver with an asymmetric architecture is proposed to achieve high energy efficiency according to the asymmetric communication in WBANs. The transceiver consists of a main receiver (RX) with an ultra-low-power free-running ring oscillator and a high speed main transmitter (TX) with fast lock-in PLL. A passive wake-up receiver (WuRx) for wake-up function with a high power conversion efficiency (PCE) CMOS rectifier is designed to offer the sensor node the capability of work-on-demand with zero standby power. The chip is implemented in a 0.18 μm CMOS process. Its core area is 1.6 mm2. The main RX achieves a sensitivity of -55 dBm at a 100 kbps OOK data rate while consuming just 210 μA current from the 1 V power supply. The main TX achieves +3 dBm output power with a 4 Mbps/500 kbps/200 kbps data rate for OOK/4 FSK/2 FSK modulation and dissipates 3.25 mA/6.5 mA/6.5 mA current from a 1.8 V power supply. The minimum detectable RF input energy for the wake-up RX is -15 dBm and the PCE is more than 25%.

  20. An ultra-low-power RF transceiver for WBANs in medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Qi; Wu Nanjian [State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Kuang Xiaofei, E-mail: nanjian@semi.ac.cn [College of Electronic Information, Hangzhou Dianzi University, Hangzhou 310018 (China)

    2011-06-15

    A 2.4 GHz ultra-low-power RF transceiver with a 900 MHz auxiliary wake-up link for wireless body area networks (WBANs) in medical applications is presented. The RF transceiver with an asymmetric architecture is proposed to achieve high energy efficiency according to the asymmetric communication in WBANs. The transceiver consists of a main receiver (RX) with an ultra-low-power free-running ring oscillator and a high speed main transmitter (TX) with fast lock-in PLL. A passive wake-up receiver (WuRx) for wake-up function with a high power conversion efficiency (PCE) CMOS rectifier is designed to offer the sensor node the capability of work-on-demand with zero standby power. The chip is implemented in a 0.18 {mu}m CMOS process. Its core area is 1.6 mm{sup 2}. The main RX achieves a sensitivity of -55 dBm at a 100 kbps OOK data rate while consuming just 210 {mu}A current from the 1 V power supply. The main TX achieves +3 dBm output power with a 4 Mbps/500 kbps/200 kbps data rate for OOK/4 FSK/2 FSK modulation and dissipates 3.25 mA/6.5 mA/6.5 mA current from a 1.8 V power supply. The minimum detectable RF input energy for the wake-up RX is -15 dBm and the PCE is more than 25%. (semiconductor integrated circuits)

  1. High-power rf pulse compression with SLED-II at SLAC

    Energy Technology Data Exchange (ETDEWEB)

    Nantista, C. [California Univ., Los Angeles, CA (United States). Dept. of Physics; Kroll, N.M. [California Univ., San Diego, La Jolla, CA (United States). Dept. of Physics; Farkas, Z.D.; Lavine, T.L.; Menegat, A.; Ruth, R.D.; Tantawi, S.G.; Vlieks, A.E.; Wilson, P.B. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)

    1993-04-01

    Increasing the peak rf power available from X-band microwave tubes by means of rf pulse compression is envisioned as a way of achieving the few-hundred-megawatt power levels needed to drive a next-generation linear collider with 50--100 MW klystrons. SLED-II is a method of pulse compression similar in principal to the SLED method currently in use on the SLC and the LEP injector linac. It utilizes low-los resonant delay lines in place of the storage cavities of the latter. This produces the added benefit of a flat-topped output pulse. At SLAC, we have designed and constructed a prototype SLED-II pulse-compression system which operates in the circular TE{sub 01} mode. It includes a circular-guide 3-dB coupler and other novel components. Low-power and initial high-power tests have been made, yielding a peak power multiplication of 4.8 at an efficiency of 40%. The system will be used in providing power for structure tests in the ASTA (Accelerator Structures Test Area) bunker. An upgraded second prototype will have improved efficiency and will serve as a model for the pulse compression system of the NLCTA (Next Linear Collider Test Accelerator).

  2. High-power rf pulse compression with SLED-II at SLAC

    Energy Technology Data Exchange (ETDEWEB)

    Nantista, C. [California Univ., Los Angeles, CA (United States). Dept. of Physics; Kroll, N.M. [California Univ., San Diego, La Jolla, CA (United States). Dept. of Physics; Farkas, Z.D.; Lavine, T.L.; Menegat, A.; Ruth, R.D.; Tantawi, S.G.; Vlieks, A.E.; Wilson, P.B. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)

    1993-04-01

    Increasing the peak rf power available from X-band microwave tubes by means of rf pulse compression is envisioned as a way of achieving the few-hundred-megawatt power levels needed to drive a next-generation linear collider with 50--100 MW klystrons. SLED-II is a method of pulse compression similar in principal to the SLED method currently in use on the SLC and the LEP injector linac. It utilizes low-los resonant delay lines in place of the storage cavities of the latter. This produces the added benefit of a flat-topped output pulse. At SLAC, we have designed and constructed a prototype SLED-II pulse-compression system which operates in the circular TE{sub 01} mode. It includes a circular-guide 3-dB coupler and other novel components. Low-power and initial high-power tests have been made, yielding a peak power multiplication of 4.8 at an efficiency of 40%. The system will be used in providing power for structure tests in the ASTA (Accelerator Structures Test Area) bunker. An upgraded second prototype will have improved efficiency and will serve as a model for the pulse compression system of the NLCTA (Next Linear Collider Test Accelerator).

  3. A digitally calibrated CMOS RMS power detector for RF automatic gain control

    Institute of Scientific and Technical Information of China (English)

    Yan Taotao; Wang Hui; Li Jinbo; Zhou Jianjun

    2013-01-01

    This paper presents the design and implementation of a digitally calibrated CMOS wideband radio frequency (RF) root-mean-square (RMS) power detector for high accuracy RF automatic gain control (AGC).The proposed RMS power detector demonstrates accurate power detection in the presence of process,supply voltage,and temperature (PVT) variations by employing a digital calibration scheme.It also consumes low power and occupies a small chip area.The measurement results show that the scheme improves the accuracy of the detector to better than 0.3 dB over the PVT variations and wide operating frequency range from 0.2 to 0.8 GHz.Implemented in a 0.18 μm CMOS process and occupying a small die area of 263 × 214 μm2,the proposed digitally calibrated CMOS RMS power detector only consumes 1.6 mA in power detection mode and 2.1 mA in digital calibration mode from a 1.8 V supply voltage.

  4. Investigations of DC power supplies with optoelectronic transducers and RF energy converters

    Science.gov (United States)

    Guzowski, B.; Gozdur, R.; Bernacki, L.; Lakomski, M.

    2016-04-01

    Fiber Distribution Cabinets (FDC) monitoring systems are increasingly popular. However it is difficult to realize such system in passive FDC, due to lack of source of power supply. In this paper investigation of four different DC power supplies with optoelectronic transducers is described. Two converters: photovoltaic power converter and PIN photodiode can convert the light transmitted through the optical fiber to electric energy. Solar cell and antenna RF-PCB are also tested. Results presented in this paper clearly demonstrate that it is possible to build monitoring system in passive FDC. During the tests maximum obtained output power was 11 mW. However all converters provided enough power to excite 32-bit microcontroller with ARM-cores and digital thermometer.

  5. Flexible low-power RF nanoelectronics in the GHz regime using CVD MoS2

    Science.gov (United States)

    Yogeesh, Maruthi

    Two-dimensional (2D) materials have attracted substantial interest for flexible nanoelectronics due to the overall device mechanical flexibility and thickness scalability for high mechanical performance and low operating power. In this work, we demonstrate the first MoS2 RF transistors on flexible substrates based on CVD-grown monolayers, featuring record GHz cutoff frequency (5.6 GHz) and saturation velocity (~1.8×106 cm/s), which is significantly superior to contemporary organic and metal oxide thin-film transistors. Furthermore, multicycle three-point bending results demonstrated the electrical robustness of our flexible MoS2 transistors after 10,000 cycles of mechanical bending. Additionally, basic RF communication circuit blocks such as amplifier, mixer and wireless AM receiver have been demonstrated. These collective results indicate that MoS2 is an ideal advanced semiconducting material for low-power, RF devices for large-area flexible nanoelectronics and smart nanosystems owing to its unique combination of large bandgap, high saturation velocity and high mechanical strength.

  6. Suppression of multipacting in high power RF couplers operating with superconducting cavities

    Science.gov (United States)

    Ostroumov, P. N.; Kazakov, S.; Morris, D.; Larter, T.; Plastun, A. S.; Popielarski, J.; Wei, J.; Xu, T.

    2017-06-01

    Capacitive input couplers based on a 50 Ω coaxial transmission line are frequently used to transmit RF power to superconducting (SC) resonators operating in CW mode. It is well known that coaxial transmission lines are prone to multipacting phenomenon in a wide range of RF power level and operating frequency. The Facility for Rare Isotope Beams (FRIB) being constructed at Michigan State University includes two types of quarter wave SC resonators (QWR) operating at 80.5 MHz and two types of half wave SC resonators (HWR) operating at 322 MHz. As was reported in ref. [1] a capacitive input coupler used with HWRs was experiencing strong multipacting that resulted in a long conditioning time prior the cavity testing at design levels of accelerating fields. We have developed an insert into 50 Ω coaxial transmission line that provides opportunity to bias the RF coupler antenna and protect the amplifier from the bias potential in the case of breakdown in DC isolation. Two of such devices have been built and are currently used for the off-line testing of 8 HWRs installed in the cryomodule.

  7. Study on Volterra-Laguerre behavioral model for RF power amplifier

    Institute of Scientific and Technical Information of China (English)

    Nan Jingchang; Liu Yuanan; Tang Bihua

    2007-01-01

    Volterra series behavioral model for radio frequency(RF)power amplifier(PA)has been widely used in system-level simulation,however,high computational complexity makes this kind of model limited to"weak"nonlinearity.In order to reduce the computational complexity and the number of coefficients of Volterra series kernels,a Volterra series improved behavioral model based on Lasuerre orthogonal polynomials function,namely Volterra-Laguerre behavioral model,is proposed.Mathematical expressions of Volterra-Laguerre behavioral model is derived.and accuracy of the model is verified through comparison of measured and simulation output data from a freescale PA using MRF21030 transistor.Mathematical analysis and simulation results show that Volterra-Laguerre behavioral model has a simple structure,much less coefficients and better modeling performance than general Volterra series model.The model can be used more correctly for system-level simulation of RF PA with wideband signal.

  8. Electronically Tunable Impedance-Matching Networks for Intelligent RF Power Amplifiers

    Directory of Open Access Journals (Sweden)

    Liang Li

    2013-11-01

    Full Text Available This paper presents the simulation and optimization design of the electronically tunable impedance-matching networks for intelligent RF power amplifiers in a cognitive radio system. Reconfigurable elements, such as varactors and RF switches are utilized to achieve the dynamic impedance matching both in the input and output matching circuit, providing coarse and fine tuning of the target impedances with low loss and excellent impedance coverage from 500MHz to 800MHz. The topology of varactor model is illustrated to ensure the precision of simulation. In addition, high-precision bias voltage controlling system is designed to improve the nonlinear problem caused by the varactor. The simulation results demonstrate the excellent performance of the tunable networks, satisfying the requirement of the cognitive radio systems.  

  9. Effect of the RF sputtering power on microstructural, optical and electrical properties of Al doped ZnO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Spadoni, A.; Addonizio, M.L., E-mail: marialuisa.addonizio@enea.it

    2015-08-31

    ZnO:Al (AZO) thin films have been deposited by radio frequency (RF) magnetron sputtering and RF power applied to the target has been varied in the range 600–1200 W. RF power effect on structural, electrical and optical properties was investigated and the relationship existing between these properties and the film lattice defect distribution was discussed. At the increasing of the RF power it was found that AZO films, having a preferential growth orientation along (002) direction, showed a decrease of the lattice distance indicating a less defected structure. Furthermore, at the increase of the RF power a higher optical absorption by free carriers, coupled with an increase of the band gap value, was observed. Resistivity varied from 1.1 × 10{sup −3} Ω cm at 600 W down to a minimum value of 5.6 × 10{sup −4} Ω cm at 1200 W, whereas the carrier density increased up to 1 × 10{sup 21} cm{sup −3}. Lattice defect variation of AZO films was analyzed by photoluminescence (PL) measurements. Presence and amount of different lattice defects were evaluated for AZO films deposited at different RF powers. At 600 W the film structure was dominated by zinc vacancies (V{sub Zn}), whereas for higher RF power the PL band associated with V{sub Zn} decreased and interstitial oxygen (O{sub i}) band remarkably increased. PL analysis revealed that extrinsic Al doping is the dominant effect on the conductivity enhancement. It was hypothesized that at higher RF power a more effective diffusion phenomenon can give more effective Al doping and less amount of zinc vacancies. As a consequence, Al atoms are more effectively trapped into the structure. - Highlights: • ZnO:Al thin films have been deposited by RF sputtering technique. • The effect of the sputtering power on film properties has been investigated. • Electrical, optical and structural characterization has been carried out. • PL analysis revealed lattice defect chemistry variation at the increase of RF power.

  10. High RF power test of a lower hybrid module mock-up in carbon fiber composite

    Energy Technology Data Exchange (ETDEWEB)

    Goniche, M.; Bibet, P.; Brossaud, J.; Cano, V.; Froissard, P.; Kazarian, F.; Rey, G. [Association Euratom-CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee; Maebara, S.; Kiyono, K.; Seki, M.; Suganuma, K.; Ikeda, Y.; Imai, T. [Japan Atomic Energy Research Inst., Tokyo (Japan). Dept. of Fusion Facility

    1999-02-01

    A mock-up module of a Lower Hybrid Current Drive antenna module of a Carbon Fiber Composite (CFC) was fabricated for the development of heat resistive front facing the plasma. This module is made from CFC plates and rods which are copper coated to reduce the RF losses. The withstand-voltage, the RF properties and outgassing rates for long pulses and high RF power were tested at the Lower Hybrid test bed facility of Cadarache. After the short pulse conditioning, long pulses with a power density ranging between 50 and 150 MW/m{sup 2} were performed with no breakdowns. During these tests, the module temperaturewas increasing from 100-200 deg. C to 400-500 deg. C. It was also checked that high power density, up to 150 MW/m{sup 2}, could be transmitted when the waveguides are filled with H{sub 2} at a pressure of 5 x 10{sup -2} Pa. No significant change in the reflection coefficient is measured after the long pulse operation. During a long pulse, the power reflection increases during the pulse typically from 0.8% to 1.3%. It is concluded that the outgassing rate of Cu-plated CFC is about 6 times larger than of Dispersion Strengthened Copper (DSC) module at the module temperature of 300 deg. C. No significant increase of the global outgassing of the CFC module was measured after hydrogen pre-filling. After the test, visual inspection revealed that peeling of the copper coating occurred at one end of the module only on a very small area (0.2 cm{sup 2}). It is assessed that a CFC module is an attractive candidate for the hardening of the tip of the LHCD antenna. (authors)

  11. High-Power Hybrid Mode-Locked External Cavity Semiconductor Laser Using Tapered Amplifier with Large Tunability

    Directory of Open Access Journals (Sweden)

    Andreas Schmitt-Sody

    2008-01-01

    Full Text Available We report on hybrid mode-locked laser operation of a tapered semiconductor amplifier in an external ring cavity, generating pulses as short as 0.5 ps at 88.1 MHz with an average power of 60 mW. The mode locking is achieved through a combination of a multiple quantum well saturable absorber (>10% modulation depth and an RF current modulation. This designed laser has 20 nm tuning bandwidth in continuous wave and 10 nm tuning bandwidth in mode locking around 786 nm center wavelength at constant temperature.

  12. A Self-Powered Hybrid Energy Scavenging System Utilizing RF and Vibration Based Electromagnetic Harvesters

    Science.gov (United States)

    Uluşan, H.; Gharehbaghi, K.; Zorlu, Ö.; Muhtaroğlu, A.; Külah, H.

    2015-12-01

    This study presents a novel hybrid system that combines the power generated simultaneously by a vibration-based Electromagnetic (EM) harvester and a UHF band RF harvester. The novel hybrid scavenger interface uses a power management circuit in 180 nm CMOS technology to step-up and to regulate the combined output. At the first stage of the system, the RF harvester generates positive DC output with a 7-stage threshold compensated rectifier, while the EM harvester generates negative DC output with a self-powered AC/DC negative doubler circuit. At the second stage, the generated voltages are serially added, stepped-up with an on-chip charge pump circuit, and regulated to a typical battery voltage of 3 V. Test results indicate that the hybrid operation enables generation of 9 μW at 3 V output for a wide range of input stimulations, which could not be attained with either harvesting mode by itself. Moreover the hybrid system behaves as a typical battery, and keeps the output voltage stable at 3 V up to 18 μW of output power. The presented system is the first battery-like harvester to our knowledge that generates energy from two independent sources and regulates the output to a stable DC voltage.

  13. Low Power Universal Direct Conversion Transmit and Receive (UTR) RF Module for Software Defined Radios Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Conventional software defined radio (SDR) backend signal processors are limited by apriori system definitions and respectively chosen RF hardware. Ideally, the RF...

  14. 76 FR 57897 - Energy Conservation Program: Energy Conservation Standards for Certain External Power Supplies

    Science.gov (United States)

    2011-09-19

    ... RIN 1904-AB57 Energy Conservation Program: Energy Conservation Standards for Certain External Power... exclude external power supplies used in specific applications from certain energy conservation standards prescribed under the Energy Policy and Conservation Act (EPCA). Congress enacted this exclusion,...

  15. Normal-Conducting High Current RF Photoinjector for High Power CW FEL

    CERN Document Server

    Kurennoy, Sergey; Nguyen, Dinh C; Rathke, John; Schrage, Dale L; Schultheiss, Tom; Wood, Richard L; Young, Lloyd M

    2005-01-01

    An RF photoinjector capable of producing high average current with low emittance and energy spread is a key enabling technology for high power CW FEL. The design of a 2.5-cell, pi-mode, 700-MHz normal-conducting RF photoinjector cavity with magnetic emittance compensation is completed. With average gradients of 7, 7, and 5 MV/m in its three accelerating cells, the photoinjector will produce a 2.5-MeV electron beam with 3-nC charge per bunch and transverse rms emittance below 7 mm-mrad. Electromagnetic modeling has been used extensively to optimize ridge-loaded tapered waveguides and RF couplers, and led to a new, improved coupler iris design. The results, combined with a thermal and stress analysis, show that the challenging problem of cavity cooling can be successfully solved. Fabrication of a demo 100-mA (at 35 MHz bunch repetition rate) photoinjector is underway. The design is scalable to higher average currents by increasing the electron bunch repetition rate, and provides a path to a MW-class FEL. This p...

  16. Systematic Observation of Time-Dependent Phenomena in the RF Output Spectrum of High Power Gyrotrons

    Directory of Open Access Journals (Sweden)

    Kern Stefan

    2012-09-01

    Full Text Available At IHM/KIT, high power gyrotrons with conventional cavity (e.g. 1 MW CW at 140 GHz for the stellarator Wendelstein 7-X and coaxial cavity (2 MW shortpulse at 170 GHz for ITER for fusion applications are being developed and verified experimentally. Especially with respect to the problem of parasitic RF oscillations in the beam tunnel of some W7-X tubes, investigations of the gyrotron RF output spectrum have proved to be a valuable source of diagnostic information. Signs of transient effects in millisecond pulses, like frequency switching or intermittent low-frequency modulation, have indicated that truly time-dependent measurements with high frequency resolution and dynamic range could give deeper insight into these phenomena. In this paper, an improved measurement system is presented, which employs a fast oscilloscope as receiver. Shorttime Fourier transform (STFT is applied to the time-domain signal, yielding time-variant spectra with frequency resolutions only limited by acquisition length and STFT segmentation choice. Typical reasonable resolutions are in the range of 100 kHz to 10 MHz with a currently memory-limited maximum acquisition length of 4 ms. A key feature of the system consists in the unambiguity of frequency measurement: The system receives through two parallel channels, each using a harmonic mixer (h = 9 – 12 to convert the signal from RF millimeter wave frequencies (full D-Band, 110 – 170 GHz to IF (0 – 3 GHz. For each IF output signal of each individual mixer, injection side and receiving harmonic are initially not known. Using accordingly determined LO frequencies, this information is retrieved from the redundancy of the channels, yielding unambiguously reconstructed RF spectra with a total span of twice the usable receiver IF bandwidth, up to ≈ 6 GHz in our case. Using the system, which is still being improved continuously, various transient effects like cavity mode switching, parasitic oscillation frequency variation

  17. Comparative electromagnetic analysis of ridge waveguide transitions for RF power couplers

    Science.gov (United States)

    Kumar, Rajesh; Singh, P.; Mathur, Pratigya; Kumar, Girish

    2014-02-01

    Ridge waveguide transitions have been used in the high power couplers of many ongoing high intensity proton accelerator projects worldwide. Because of their smaller size and high energy densities, they require strict dimensional tolerances during fabrication and operating conditions. In order to study their electromagnetic characteristics, two different types of transitions with a straight ridge and a tapered ridge are compared using full wave simulations. Apart from the return loss and resonant frequency variation with dimensions, comparative studies on the phase shift, insertion losses, electric and magnetic field distributions and multipacting are also reported. This analysis will be useful in selecting the appropriate ridge waveguide transition for the RF couplers of accelerator cavities.

  18. Magnet-free uniform sputtering of dielectric film by RF and microwave power superposition

    Science.gov (United States)

    Sasai, Kensuke; Hagihara, Toshiya; Noda, Tomonori; Suzuki, Haruka; Toyoda, Hirotaka

    2016-08-01

    A novel sputtering device that is free of magnets (magnet-free surface wave sputtering plasma: MF-SSP) is developed by combining a surface wave plasma and RF bias power. Low-pressure (<0.5 Pa) plasma sustainment is demonstrated by MF-SSP with a uniform sputter deposition rate with a deviation of less than 5% within an area of 10 × 10 cm2. Highly oriented MgO films are deposited at a substrate temperature of 200 °C.

  19. RF power fading mitigation for an IMDD multicarrier LR-PON.

    Science.gov (United States)

    Chen, You-Wei; Lai, Tsan-Ning; Chang, Mu-Fan; Feng, Kai-Ming

    2016-08-22

    In an intensity-modulation direct-detection (IMDD) orthogonal frequency division multiplexing (OFDM) signal format, radio frequency (RF) power fading produces non-uniform receiving performance among the subcarriers due to chromatic dispersion. Hence each subscriber experiences distinct quality of service (QoS) in conventional frequency division multiple access (FDMA). In this paper, a multicarrier code division multiple access (MC-CDMA) signal along with multicode interference (MCI) cancellation process is proposed and experimentally demonstrated to enhance the receiving performance in an IMDD long reach passive optical network (LR-PON). With the proposed scheme, the receiving performance of each subcarrier can be equalized so that a universal transmitter design at central office (CO) can support all the subscribers with their locations ranging from back-to-back to 100 km. Our experimental results also reveal that, even under 20 dB RF power fading, the proposed scheme can still provide over 21.7 dB power budget and only approximately 2 dB sensitivity deviation is observed in an IMDD LR-PON system.

  20. AN ALTERNATIVE APPROACH TO LOW FREQUENCY RF ACCELERATORS AND POWER SOURCES.

    Energy Technology Data Exchange (ETDEWEB)

    ZHAO, Y.

    2001-06-18

    The Muon Collider and Neutrino Factory projects require low frequency rf cavities because the size and emittance of the muon beam is much larger than is usual for electron or proton beams. The range of 30 MHz to 200 MHz is of special interest. However, the size of an accelerator with low frequency will be impractically large if it is simply scaled up from usual designs. In addition, to get very high peak power in this range is difficult. Presented in this paper is an alternative structure that employs a quasi-lumped inductance that can significantly reduce the transverse size while keeping high gradient. Also addressed is a power compression scheme with a thyratron. This gives a possible solution to provide very high peak power.

  1. A compact 10 kW solid-state RF power amplifier at 352 MHz

    Science.gov (United States)

    Dancila, Dragos; Hoang Duc, Long; Jobs, Magnus; Holmberg, Måns; Hjort, Adam; Rydberg, Anders; Ruber, Roger

    2017-07-01

    A compact 10 kW RF power amplifier at 352 MHz was developed at FREIA for the European Spallation Source, ESS. The specifications of ESS for the conception of amplifiers are related to its pulsed operation: 3.5 ms pulse length and a duty cycle of 5%. The realized amplifier is composed of eight kilowatt level modules, combined using a planar Gysel 8-way combiner. The combiner has a low insertion loss of only 0.2 dB, measured at 10 kW peak power. Each module is built around a commercially available LDMOS transistor in a singleended architecture. During the final tests, a total output peak power of 10.5 kW was measured.

  2. High Powered Tests of Dielectric Loaded High Pressure RF Cavities for Use in Muon Cooling Channels

    Energy Technology Data Exchange (ETDEWEB)

    Freemire, Ben [IIT, Chicago; Bowring, Daniel [Fermilab; Kochemirovskiy, Alexey [Chicago U.; Moretti, Alfred [Fermilab; Peterson, David [Fermilab; Tollestrup, Alvin [Fermilab; Torun, Yagmur [IIT, Chicago; Yonehara, Katsuya [Fermilab

    2016-06-01

    Bright muon sources require six dimensional cooling to achieve acceptable luminosities. Ionization cooling is the only known method able to do so within the muon lifetime. One proposed cooling channel, the Helical Cooling Channel, utilizes gas filled radio frequency cavities to both mitigate RF breakdown in the presence of strong, external magnetic fields, and provide the cooling medium. Engineering constraints on the diameter of the magnets within which these cavities operate dictate the radius of the cavities be decreased at their nominal operating frequency. To accomplish this, one may load the cavities with a larger dielectric material. Alumina of purities ranging from 96 to 99.8% was tested in a high pressure RF test cell at the MuCool Test Area at Fermilab. The results of breakdown studies with pure nitrogen gas, and oxygen-doped nitrogen gas indicate the peak surface electric field on the alumina ranges between 10 and 15 MV/m. How these results affect the design of a prototype cooling channel cavity will be discussed.

  3. Effect of RF Interference on the Security-Reliability Trade-off Analysis of Multiuser Mixed RF/FSO Relay Networks with Power Allocation

    KAUST Repository

    Abd El-Malek, Ahmed

    2017-03-27

    In this paper, the impact of radio frequency (RF) cochannel interference (CCI) on the performance of multiuser mixed RF/free-space optical (FSO) relay network with opportunistic user scheduling under eavesdropping attack is studied. The considered system includes multiple users, one decode-and-forward relay, one destination, and an eavesdropper. In the analysis, the RF/FSO channels follow Nakagami-m/Gamma-Gamma fading models, respectively, with pointing errors on the FSO link. Exact closed-form expression for the system outage probability is derived. Then, an asymptotic expression for the outage probability is obtained at the high signal-to-interference-plus-noise ratio regime to get more insights on the system performance. Moreover, the obtained results are used to find the optimal transmission power in different turbulence conditions. The secrecy performance is studied in the presence of CCI at both the authorized relay and eavesdropper, where closed-form expressions are derived for the intercept probability. The physical layer security performance is enhanced using cooperative jamming models, where new closed-form expressions are derived for the intercept probability. Another power allocation optimization problem is formulated to find the optimal transmission and jamming powers. The derived analytical formulas are supported by numerical results to clarify the main contributions of this paper.

  4. Operational Performance and Improvements to the RF Power Sources for the Compact Linear Collider Test Facility (CTF3) at CERN

    CERN Document Server

    McMonagle, Gerard

    2006-01-01

    The CERN CTF3 facility is being used to test and demonstrate key technical issues for the CLIC (Compact Linear Collider) study. Pulsed RF power sources are essential elements in this test facility. Klystrons at S-band (29998.55 GHz), in conjunction with pulse compression systems, are used to power the Drive Beam Accelerator (DBA) to achieve an electron beam energy of 150 MeV. The L-Band RF system, includes broadband Travelling Wave Tubes (TWTs) for beam bunching with 'phase coded' sub pulses in the injector and a narrow band high power L-Band klystron powering the transverse 1.5GHz RF deflector in the Delay Loop immediately after the DBA. This paper describes these different systems and discusses their operational performance.

  5. Operational performance and improvements to the rf power sources for the Compact Linear Collider Test Facility (CTF3) at CERN

    CERN Document Server

    McMonagle, Gerard

    2006-01-01

    The CERN CTF3 facility is being used to test and demonstrate key technical issues for the CLIC (Compact Linear Collider) study. Pulsed RF power sources are essential elements in this test facility. Klystrons at S-band (29998.55 GHz), in conjunction with pulse compression systems, are used to power the Drive Beam Accelerator (DBA) to achieve an electron beam energy of 150 MeV. The L-Band RF system, includes broadband Travelling Wave Tubes (TWTs) for beam bunching with 'phase coded' sub pulses in the injector and a narrow band high power L-Band klystron powering the transverse 1.5 GHz RF deflector in the Delay Loop immediately after the DBA. This paper describes these different systems and discusses their operational performance.

  6. 外注入式独立调谐微波电子枪的概念设计%Conceptual design of independently tunable cells RF gun with external injecting structure

    Institute of Scientific and Technical Information of China (English)

    梁军军; 冯光耀; 裴元吉; 庞健

    2012-01-01

    为得到微脉冲束团长度在百fs量级且高重复频率,设计了一种紧凑型的强流电子枪结构——独立调谐微波热发射电子枪.该电子腔具有双驻波加速腔,两个驻波加速腔之间相互没有耦合,可以分别独立地馈入功率、调节相位.通过优化功率与相位,可以得到较优的束流品质,同时避免了α磁铁和激光系统的使用,使得结构更加紧凑.并采用外注入式结构增大流强、降低能散度,同时消除电子反轰对阴极的负面影响.对不同结构参数的腔体进行1维和3维束流动力学计算,可以得到较为理想的腔体参数.通过调节预注入器的馈入功率和粒子入射相位,可以进一步的压缩束团长度.%To obtain the micro-pulse bunch with the order of hundred femtoseconds length and high repetition rate, the paper proposes the independently tunable cells (ITC) RF gun. Which has a double-cell structure with the cells being power fed independently. By choosing appropriate feeding power and phase of the two cells, this ITC-RF gun can achieve bunches of excellent characteristics. Additionally, the application of α-magnet and laser system can be avoided, which leads to more compact layout. An external injecting ITC-RF gun (DC-ITC-RF gun) structure is designed accordingly. The external injecting structure can increase beam current, decrease energy spread, and cancel the back-bombardment effect almost completely. By means of 1-D and 3-D beam dynamics calculation with different structure parameters, a group of RF parameters are obtained for better beam characteristics. Then the paper designs a pre-injector so that particles can be accelerated to 10 MeV. By choosing appropriate feeding power and incident particle phase for the pre-injector, the bunch length can be further compressed.

  7. Reliability studies on NPN RF power transistors under swift heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Pushpa, N.; Praveen, K.C. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India); Gnana Prakash, A.P., E-mail: gnanaprakash@physics.uni-mysore.ac.in [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India); Naik, P.S. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India); Cressler, John D. [School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta 30308 (United States); Gupta, S.K. [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Revannasiddaiah, D. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India)

    2012-02-15

    NPN RF power transistors were irradiated with 140 MeV Si{sup 10+} ions, 100 MeV F{sup 8+} ions, 50 MeV Li{sup 3+} ions and Co-60 gamma radiation in the dose range from 100 krad to 100 Mrad. The transistor characteristics are studied before and after irradiation from which the parameters such as Gummel characteristics, excess base current ({Delta}I{sub B} = I{sub Bpost} - I{sub Bpre}), dc current gain (h{sub FE}), transconductance (g{sub m}) and collector-saturation current (I{sub CSat}) are determined. The degradation observed in the electrical characteristics is almost the same for different types of ion irradiated NPN RF power transistors with similar total doses although there is a large difference in the linear energy transfer (LET) of the ions. Further, it was observed more degradation in DC I-V characteristics of ion irradiated devices than the Co-60 gamma irradiated devices for higher doses.

  8. Development of photoinjector RF cavity for high-power CW FEL

    Science.gov (United States)

    Kurennoy, S. S.; Schrage, D. L.; Wood, R. L.; Young, L. M.; Schultheiss, T.; Christina, V.; Rathke, J.

    2004-08-01

    An RF photoinjector capable of producing high continuous average current with low emittance and energy spread is a key enabling technology for high-power CW FEL. A preliminary design of the first, and the most challenging, section of a 700-MHz CW RF normal-conducting photoinjector—a 2.5-cell, pi-mode cavity with solenoidal magnetic field for emittance compensation—is completed. Beam dynamics simulations demonstrate that this cavity with an electric field gradient of 7 MV/m will produce an electron beam at 2.7 MeV with the transverse rms emittance 7 mm mrad at 3 nC of charge per bunch. Electromagnetic field computations combined with a thermal and stress analysis show that the challenging problem of cavity cooling can be successfully resolved. We are in the process of building a 100-mA (3 nC of bunch charge at 33.3 MHz bunch repetition rate) photoinjector for demonstration purposes. Its performance parameters will enable a robust 100-kW-class FEL operation with electron beam energy below 100 MeV. The design is scalable to higher power levels by increasing the electron bunch repetition rate and provides a path to a MW-class amplifier FEL.

  9. Development of photoinjector RF cavity for high-power CW FEL

    Energy Technology Data Exchange (ETDEWEB)

    Kurennoy, S.S. E-mail: kurennoy@lanl.gov; Schrage, D.L.; Wood, R.L.; Young, L.M.; Schultheiss, T.; Christina, V.; Rathke, J

    2004-08-01

    An RF photoinjector capable of producing high continuous average current with low emittance and energy spread is a key enabling technology for high-power CW FEL. A preliminary design of the first, and the most challenging, section of a 700-MHz CW RF normal-conducting photoinjector - a 2.5-cell, pi-mode cavity with solenoidal magnetic field for emittance compensation - is completed. Beam dynamics simulations demonstrate that this cavity with an electric field gradient of 7 MV/m will produce an electron beam at 2.7 MeV with the transverse rms emittance 7 mm mrad at 3 nC of charge per bunch. Electromagnetic field computations combined with a thermal and stress analysis show that the challenging problem of cavity cooling can be successfully resolved. We are in the process of building a 100-mA (3 nC of bunch charge at 33.3 MHz bunch repetition rate) photoinjector for demonstration purposes. Its performance parameters will enable a robust 100-kW-class FEL operation with electron beam energy below 100 MeV. The design is scalable to higher power levels by increasing the electron bunch repetition rate and provides a path to a MW-class amplifier FEL.

  10. Can we estimate the cellular phone RF peak output power with a simple experiment?

    Science.gov (United States)

    Fioreze, Maycon; dos Santos Junior, Sauli; Goncalves Hönnicke, Marcelo

    2016-07-01

    Cellular phones are becoming increasingly useful tools for students. Since cell phones operate in the microwave bandwidth, they can be used to motivate students to demonstrate and better understand the properties of electromagnetic waves. However, since these waves operate at higher frequencies (L-band, from 800 MHz to 2 GHz) it is not simple to detect them. Usually, expensive real-time high frequency oscilloscopes are required. Indirect measurements are also possible through heat-based and diode-detector-based radio-frequency (RF) power sensors. Another didactic and intuitive way is to explore a simple and inexpensive detection system, based on the interference effect caused in the electronic circuit of TV and PC soundspeakers, and to try to investigate different properties of the cell phones’ RF electromagnetic waves, such as its power and modulated frequency. This manuscript proposes a trial to quantify these measurements, based on a simple Friis equation model and the time constant of the circuit used in the detection system, in order to show it didactically to the students and even allow them also to explore such a simple detection system at home.

  11. The drive beam pulse compression system for the CLIC RF power source

    CERN Document Server

    Corsini, R

    1999-01-01

    The Compact LInear Collider (CLIC) is a high energy (0.5 to 5 TeV) e ± linear collider that uses a high- current electron beam (the drive beam) for 30 GHz RF power production by the Two-Beam Acceleration (TBA) method. Recently, a new cost­effective and efficient generation scheme for the drive beam has been developed. A fully­loaded normal­conducting linac operating at lower frequency (937 MHz) generates and accelerates the drive beam bunches, and a compression system composed of a delay­line and two combiner rings produces the proper drive beam time structure for RF power generation in the drive beam decelerator. In this paper, a preliminary design of the whole compression system is presented. In particular, the fundamental issue of preserving the bunch quality along the complex is studied and its impact on the beam parameters and on the various system components is assessed. A first design of the rings and delay­line lattice, including path length tuning chicanes, injection and extraction regions is a...

  12. Tunable high-power blue external cavity semiconductor laser

    Science.gov (United States)

    Ding, Ding; Lv, Xueqin; Chen, Xinyi; Wang, Fei; Zhang, Jiangyong; Che, Kaijun

    2017-09-01

    A commercially available high-power GaN-based blue laser diode has been operated in a simple Littrow-type external cavity (EC). Two kinds of EC configurations with the grating lines perpendicular (A configuration) and parallel (B configuration) to the p-n junction are evaluated. Good performance has been demonstrated for the EC laser with B configuration due to the better mode selection effect induced by the narrow feedback wavelength range from the grating. Under an injection current of 1100 mA, the spectral linewidth is narrowed significantly down to ∼0.1 nm from ∼1 nm (the free-running width), with a good wavelength-locking behavior and a higher than 35 dB-amplified spontaneous emission suppression ratio. Moreover, a tuning bandwidth of 3.6 nm from 443.9 nm to 447.5 nm is realized with output power of 1.24 W and EC coupling efficiency of 80% at the central wavelength. The grating-coupled blue EC laser with narrow spectral linewidth, flexible wavelength tunability, and high output power shows potential applications in atom cooling and trapping, high-resolution spectroscopy, second harmonic generation, and high-capacity holographic data storage.

  13. Nonlinear plasma experiments in geospace with gigawatts of RF power at HAARP

    Science.gov (United States)

    Sheerin, J. P.; Cohen, Morris B.

    2015-12-01

    The ionosphere is the ionized uppermost layer of our atmosphere (from 70 - 500 km altitude) where free electron densities yield peak critical frequencies in the HF (3 - 30 MHz) range. The ionosphere thus provides a quiescent plasma target, stable on timescales of minutes, for a whole host of active plasma experiments. High power RF experiments on ionospheric plasma conducted in the U.S. have been reported since 1970. The largest HF transmitter built to date is the HAARP phased-array HF transmitter near Gakona, Alaska which can deliver up to 3.6 Gigawatts (ERP) of CW RF power in the range of 2.8 - 10 MHz to the ionosphere with microsecond pointing, power modulation, and frequency agility. With an ionospheric background thermal energy in the range of only 0.1 eV, this amount of power gives access to the highest regimes of the nonlinearity (RF intensity to thermal pressure) ratio. HAARP's unique features have enabled the conduct of a number of unique nonlinear plasma experiments in the interaction region of overdense ionospheric plasma including generation of artificial aurorae, artificial ionization layers, VLF wave-particle interactions in the magnetosphere, parametric instabilities, stimulated electromagnetic emissions (SEE), strong Langmuir turbulence (SLT) and suprathermal electron acceleration. Diagnostics include the Modular UHF Ionospheric Radar (MUIR) sited at HAARP, the SuperDARN-Kodiak HF radar, spacecraft radio beacons, HF receivers to record stimulated electromagnetic emissions (SEE) and telescopes and cameras for optical emissions. We report on short timescale ponderomotive overshoot effects, artificial field-aligned irregularities (AFAI), the aspect angle dependence of the intensity of the HF-enhanced plasma line, and production of suprathermal electrons. One of the primary missions of HAARP, has been the generation of ELF (300 - 3000 Hz) and VLF (3 - 30 kHz) radio waves which are guided to global distances in the Earth-ionosphere waveguide. We review

  14. Nonlinear plasma experiments in geospace with gigawatts of RF power at HAARP

    Energy Technology Data Exchange (ETDEWEB)

    Sheerin, J. P., E-mail: jsheerin@emich.edu [Physics and Astronomy, Eastern Michigan Univ., Ypsilanti, MI 48197 (United States); Cohen, Morris B., E-mail: mcohen@gatech.edu [Electrical and Computer Engineering, Georgia Tech, Atlanta, GA 30332-0250 (United States)

    2015-12-10

    The ionosphere is the ionized uppermost layer of our atmosphere (from 70 – 500 km altitude) where free electron densities yield peak critical frequencies in the HF (3 – 30 MHz) range. The ionosphere thus provides a quiescent plasma target, stable on timescales of minutes, for a whole host of active plasma experiments. High power RF experiments on ionospheric plasma conducted in the U.S. have been reported since 1970. The largest HF transmitter built to date is the HAARP phased-array HF transmitter near Gakona, Alaska which can deliver up to 3.6 Gigawatts (ERP) of CW RF power in the range of 2.8 – 10 MHz to the ionosphere with microsecond pointing, power modulation, and frequency agility. With an ionospheric background thermal energy in the range of only 0.1 eV, this amount of power gives access to the highest regimes of the nonlinearity (RF intensity to thermal pressure) ratio. HAARP’s unique features have enabled the conduct of a number of unique nonlinear plasma experiments in the interaction region of overdense ionospheric plasma including generation of artificial aurorae, artificial ionization layers, VLF wave-particle interactions in the magnetosphere, parametric instabilities, stimulated electromagnetic emissions (SEE), strong Langmuir turbulence (SLT) and suprathermal electron acceleration. Diagnostics include the Modular UHF Ionospheric Radar (MUIR) sited at HAARP, the SuperDARN-Kodiak HF radar, spacecraft radio beacons, HF receivers to record stimulated electromagnetic emissions (SEE) and telescopes and cameras for optical emissions. We report on short timescale ponderomotive overshoot effects, artificial field-aligned irregularities (AFAI), the aspect angle dependence of the intensity of the HF-enhanced plasma line, and production of suprathermal electrons. One of the primary missions of HAARP, has been the generation of ELF (300 – 3000 Hz) and VLF (3 – 30 kHz) radio waves which are guided to global distances in the Earth

  15. RF-DC converter for HF RFID sensing applications powered by a near-field loop antenna

    Science.gov (United States)

    Colella, R.; Pasca, M.; Catarinucci, L.; Tarricone, L.; D'Amico, S.

    2016-07-01

    In this paper, an RF-DC converter operating at 13.56 MHz (HF radio frequency identification (RFID) frequency band) is presented. Its architecture provides RF to load isolation, reducing the losses due to the reverse saturation current and improving the sensitivity. Fed by a loop antenna, the RF-DC converter is made by a Dickson's RF-DC rectifier and an additional Pelliconi's charge pump driven by a fully integrated 50 kHz ring oscillator realized using an application-specific integrated circuit (ASIC). The input RF signal from the reader is converted to DC supply voltage and stored on a 1 μF capacitor. Mathematical model of the converter is developed and verified through measurements. Silicon prototypes of the ASIC have been realized in 350 nm complementary metal-oxide semiconductor technology. Measurements have been done on 10 different samples showing an output voltage in the range of 0.5 V-3.11 V in correspondence of an RF input signal power in the range of -19 dBm-0 dBm. These output voltage levels are suitable to power HF RFID sensing platforms and sensor nodes of body sensor networks.

  16. RF power upgrade at the superconducting 1.3 GHz CW LINAC “ELBE” with solid state amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Büttig, Hartmut, E-mail: buettig@hzdr.de [Radiation Source ELBE, Helmholtz Zentrum Dresden-Rossendorf (Germany); Arnold, A.; Büchner, A.; Justus, M.; Kuntsch, M.; Lehnert, U.; Michel, P.; Schurig, R.; Staats, G.; Teichert, J. [Radiation Source ELBE, Helmholtz Zentrum Dresden-Rossendorf (Germany)

    2013-03-11

    The RF power for the superconducting 1.3 GHz CW LINAC “ELBE” has been doubled from less than 10 kW to 20 kW per cavity. In January 2012 the four 10 kW klystrons used to drive the four superconducting cavities of the LINAC have been replaced by pairs of 10 kW solid state power amplifiers (SSPA). ELBE is now worldwide the first 1.3 GHz CW LINAC equipped with solid state RF power amplifiers. This technical note details on this project. -- Highlights: ► We report the first installation of 10 kW solid state RF-amplifiers at 1.3 GHz CW LINAC. ► The sc. cavities of “ELBE” are now driven by a pair of 10 kW solid state amplifiers (SSPA). ► The RF-power upgrade allows doubling the electron beam current (CW). ► Advantages of the new RF system are high reliability, easy service and lower costs.

  17. Effects of various deposition times and RF powers on CdTe thin film growth using magnetron sputtering

    Science.gov (United States)

    Ghorannevis, Z.; Akbarnejad, E.; Ghoranneviss, M.

    2016-09-01

    Cadmium telluride (CdTe) is a p-type II-VI compound semiconductor, which is an active component for producing photovoltaic solar cells in the form of thin films, due to its desirable physical properties. In this study, CdTe film was deposited using the radio frequency (RF) magnetron sputtering system onto a glass substrate. To improve the properties of the CdTe film, effects of two experimental parameters of deposition time and RF power were investigated on the physical properties of the CdTe films. X-ray Diffraction (XRD), atomic force microscopy (AFM) and spectrophotometer were used to study the structural, morphological and optical properties of the CdTe samples grown at different experimental conditions, respectively. Our results suggest that film properties strongly depend on the experimental parameters and by optimizing these parameters, it is possible to tune the desired structural, morphological and optical properties. From XRD data, it is found that increasing the deposition time and RF power leads to increasing the crystallinity as well as the crystal sizes of the grown film, and all the films represent zinc blende cubic structure. Roughness values given from AFM images suggest increasing the roughness of the CdTe films by increasing the RF power and deposition times. Finally, optical investigations reveal increasing the film band gaps by increasing the RF power and the deposition time.

  18. 77 FR 22472 - Energy Conservation Program: Energy Conservation Standards for Certain External Power Supplies...

    Science.gov (United States)

    2012-04-16

    ... Part 430 RIN 1904-AB57 Energy Conservation Program: Energy Conservation Standards for Certain External... energy conservation standards for certain external power supplies to re-insert a table that had been... statutorily-prescribed energy conservation standards for all Class A external power supplies to meet....

  19. Active experiments in geospace plasmas with gigawatts of RF power at HAARP

    Science.gov (United States)

    Sheerin, James

    2016-07-01

    The ionosphere provides a relatively quiescent plasma target, stable on timescales of minutes, for a whole host of active plasma experiments. The largest HF transmitter built to date is the HAARP phased-array HF transmitter near Gakona, Alaska which can deliver up to 3.6 Gigawatts (ERP) of CW RF power in the range of 2.8 - 10 MHz to the ionosphere with millisecond pointing, power modulation, and frequency agility. With an ionospheric background thermal energy in the range of only 0.1 eV, this amount of power gives access to the highest regimes of the nonlinearity (RF intensity to thermal pressure) ratio. HAARP's unique features have enabled the conduct of a number of nonlinear plasma experiments in the inter¬action region of overdense ionospheric plasma including generation of artificial aurorae, artificial ionization layers, VLF wave-particle interactions in the magnetosphere, parametric instabilities, stimulated electromagnetic emissions (SEE), strong Langmuir turbulence (SLT) and suprathermal electron acceleration. Diagnostics include the Modular UHF Ionospheric Radar (MUIR) sited at HAARP, the SuperDARN-Kodiak HF radar, spacecraft radio beacons, HF receivers to record stimulated electromagnetic emissions (SEE) and optics for optical emissions. We report on short timescale ponderomotive overshoot effects, artificial field-aligned irregularities (AFAI), the aspect angle dependence of the intensity of the HF-enhanced plasma line, and production of suprathermal electrons. Applications are made to the controlled study of fundamental nonlinear plasma processes of relevance to laboratory plasmas, ionospheric irregularities affecting spacecraft communication and navigation systems, artificial ionization mirrors, wave-particle interactions in the magnetosphere, active global magnetospheric experiments, and many more.

  20. Optimization of caesium dynamics in large and powerful RF sources for negative hydrogen ions

    Energy Technology Data Exchange (ETDEWEB)

    Mimo, Alessandro; Wimmer, Christian; Wuenderlich, Dirk; Fantz, Ursel [Max-Planck-Institut fuer Plasmaphysik, 85748 Garching (Germany)

    2015-05-01

    The development of large and powerful RF sources for negative hydrogen and deuterium ions is mandatory for the realization of the Neutral Beam Injection system at ITER. Caesium seeding into negative ion sources is necessary to obtain the required ion current with a tolerable level of co-extracted electrons. The caesium dynamics, during both plasma and vacuum phases, was investigated by means of the Monte Carlo transport code CsFlow3D, which is used to simulate the time evolution of the distribution of neutral and ionic caesium in the IPP prototype RF ion source. Simulations were performed for different durations of plasma-on and plasma-off phases, with the purpose of understanding how the duty cycle influences the caesium distribution and hence the source performance. In order to investigate asymmetry effects in the caesium distribution, caused by the positioning of caesium evaporator, the caesium coverage on the top and on the bottom part of the plasma grid was simulated and data were compared to the caesium density measured by laser absorption in the prototype source. The next step will be to introduce in the code the simulation of diagnostics such as laser absorption spectroscopy and optical emission spectroscopy, in order to achieve a direct benchmark of the code with experimental data.

  1. Asymmetric focusing study from twin input power couplers using realistic rf cavity field maps

    Directory of Open Access Journals (Sweden)

    Colwyn Gulliford

    2011-03-01

    Full Text Available Advanced simulation codes now exist that can self-consistently solve Maxwell’s equations for the combined system of an rf cavity and a beam bunch. While these simulations are important for a complete understanding of the beam dynamics in rf cavities, they require significant time and computing power. These techniques are therefore not readily included in real time simulations useful to the beam physicist during beam operations. Thus, there exists a need for a simplified algorithm which simulates realistic cavity fields significantly faster than self-consistent codes, while still incorporating enough of the necessary physics to ensure accurate beam dynamics computation. To this end, we establish a procedure for producing realistic field maps using lossless cavity eigenmode field solvers. This algorithm incorporates all relevant cavity design and operating parameters, including beam loading from a nonrelativistic beam. The algorithm is then used to investigate the asymmetric quadrupolelike focusing produced by the input couplers of the Cornell ERL injector cavity for a variety of beam and operating parameters.

  2. Performance of the arc detectors of LHC high power RF system

    CERN Document Server

    Valuch, D; Brunner, O

    2011-01-01

    During operation, the LHC high power RF equipment, such as klystrons, circulators, waveguides and couplers have to be protected from damage caused by electromagnetic discharges. Once ignited these arcs grow over the full height of the waveguide and travel towards the RF source. The burning plasma can cause serious damage to the metal surfaces or ferrite materials. The LHC arc detector system is based on the optical detection of the discharge through small apertures in the waveguide walls. The light is guided by means of an opti-cal fibre from the viewing port to a photo diode. Experience shows that some of the currently used optical fibres suffer from x-ray induced opacity. The sensors are also exposed to the radiation produced by secondary showers coming from the high intensity beams which, if not treated properly, can cause frequent spurious trips. In the second half of the paper we present a number of improvements to the design, measurements with optical parameters from real arcs and a fibre-less version o...

  3. Low Power Universal Direct Conversion Transmit and Receive (UTR) RF Module for Software Defined Radios Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Conventional software defined radio (SDR) backend signal processors are limited by a priori system definition and RF hardware. Ideally, advanced SDR RF front-end...

  4. Optimized Envelope Tracking Power Supply for Tetra2 Base Station RF Power Amplifier

    DEFF Research Database (Denmark)

    Høyerby, Mikkel Christian Wendelboe; Andersen, Michael Andreas E.

    2008-01-01

    An ultra-fast tracking power supply (UFTPS) for envelope tracking in a 50kHz 64-QAM Tetra2 base station power amplification system is demonstrated. A simple method for optimizing the step response of the PID+PD sliding-mode control system is presented and demonstrated, along with a PLL-based scheme...

  5. A low power dual-band multi-mode RF front-end for GNSS applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Hao; Li Zhiqun; Wang Zhigong, E-mail: zhhseu@gmail.com [Institute of RF- and OE- ICs, Southeast University, Nanjing 210096 (China)

    2010-11-15

    A CMOS dual-band multi-mode RF front-end for the global navigation satellite system receivers of all GPS, Bei-Dou, Galileo and Glonass systems is presented. It consists of a reconfigurable low noise amplifier (LNA), a broadband active balun, a high linearity mixer and a bandgap reference (BGR) circuit. The effect of the input parasitic capacitance on the input impedance of the inductively degenerated common source LNA is analyzed in detail. By using two different LC networks at the input port and the switched capacitor at the output port, the LNA can work at two different frequency bands (1.2 GHz and 1.5 GHz) under low power consumption. The active balun uses a hybrid-connection structure to achieve high bandwidth. The mixer uses the multiple gated transistors technique to acquire a high linearity under low power consumption but does not deteriorate other performances. The measurement results of the proposed front-end achieve a noise figure of 2.1/2.0 dB, again of 33.9/33.8 dB and an input 1-dB compression point of 0/1 dBm at 1227.6/1575.42 MHz. The power consumption is about 16 mW under a 1.8 V power supply.

  6. 3D simulations on output power fluctuation in a short bunch rf-linac FEL

    Science.gov (United States)

    Sentoku, Y.; Furukawa, H.; Mima, K.; Taguchi, T.; Kuruma, S.; Yasuda, H.; Yamanaka, C.; Nakai, S.

    1995-04-01

    A space-time dependent 3D simulation code has been developed in order to analyze the RF-linac FEL oscillator dynamics. Our simulation code employed both the transverse mode spectral method and the longitudinal finite difference method. The electron beam is modeled by a group of super particles which have a density profile in the time domain. In this model the electron beam is able to determine the energy spread and the finite emittance. This simulation code enables us to describe the transverse mode competition and the slippage effects in the resonator cavity. In this paper, a high power infrared FEL with a short bunch electron beam is investigated. The output power fluctuation with cavity desynchronism is simulated with this code. Especially, we investigated the effects of the transverse mode competition, energy spread, and the finite emittance of the electron beam on the output fluctuation. Using FELIX parameters, the FEL oscillator is simulated for 300 passes. The output power oscillates periodically in the case of single transverse mode and not in the case of multi-transverse modes. In a warm beam with multi-transverse modes, the emission is higher than that with a single mode, and the optical pulse shape is almost the after 100 passes. Furthermore, the phase space motion of the laser field is periodic and stable. As a result of the simulation, we recommend that high power infrared FEL operation should include multi-transverse modes in order to get higher emission and a more stable optical pulse.

  7. Self-heating and memory effects in RF power amplifiers explained through electro-thermal

    DEFF Research Database (Denmark)

    Wei, Wei; Jensen, Ole Kiel; Mikkelsen, Jan H.

    2013-01-01

    a simple electro-thermal model and shows how self-heating can generate different types of memory effects, such as bandwidth dependent intermodulation components and hysteresis loops. In addition, it is shown that self-heating can result in generation of new spectral components even in an otherwise linear......Self-heating has already been proven to be one of the key sources to memory effects in RF power amplifiers (PAs). However, mechanisms behind the generation of memory effects, as caused by self-heating have not been well documented. On basis of transistor physical properties this paper proposes...... PA. A time domain modeling framework is implemented to investigate memory effects generated by self-heating and simulation results are shown to agree with theoretical analysis....

  8. Adaptive Digital Predistortion Schemes to Linearize RF Power Amplifiers with Memory Effects

    Institute of Scientific and Technical Information of China (English)

    ZHANG Peng; WU Si-liang; ZHANG Qin

    2008-01-01

    To compensate for nonlinear distortion introduced by RF power amplifiers (PAs) with memory effects, two correlated models, namely an extended memory polynomial (EMP) model and a memory lookup table (LUT) model, are proposed for predistorter design. Two adaptive digital predistortion (ADPD) schemes with indirect learning architecture are presented. One adopts the EMP model and the recursive least square (RLS) algorithm, and the other utilizes the memory LUT model and the least mean square (LMS) algorithm. Simulation results demonstrate that the EMP-based ADPD yields the best linearization performance in terms of suppressing spectral regrowth. It is also shown that the ADPD based on memory LUT makes optimum tradeoff between performance and computational complexity.

  9. High-Bandwidth, High-Efficiency Envelope Tracking Power Supply for 40W RF Power Amplifier Using Paralleled Bandpass Current Sources

    DEFF Research Database (Denmark)

    Høyerby, Mikkel Christian Wendelboe; Andersen, Michael Andreas E.

    2005-01-01

    This paper presents a high-performance power conversion scheme for power supply applications that require very high output voltage slew rates (dV/dt). The concept is to parallel 2 switching bandpass current sources, each optimized for its passband frequency space and the expected load current....... The principle is demonstrated with a power supply, designed for supplying a 40 W linear RF power amplifier for efficient amplification of a 16-QAM modulated data stream...

  10. Environmental externalities related to power production on biogas and natural gas based on the EU ExternE methodology

    DEFF Research Database (Denmark)

    Nielsen, Per Sieverts; Ibsen, Liselotte Schleisner

    1998-01-01

    This paper assesses the environmental impacts and external costs from selected electricity generation systems in Denmark. The assessment is carried out as part of the ExternE National Implementation, which is the second phase of the ExternE project and involves case studies from all Western Europ...... show that estimated damages due to the greenhouse effect are predominant, however, the uncertainty is high. The predominant damage at the local and regional level is related to emission of NOx, which results in effects on public health....... European countries. The project use a “bottom-up” methodology to evaluate the external costs associated with a wide range of different fuel cycles. The project has identified priority impacts, where most are impacts from air emissions. Externalities due to atmospheric emissions are calculated through...... the use of a software package, EcoSence, having an environmental database at both a local and regional level including population, crops, building materials and forest. The system also incorporates two air transport models, allowing local and regional scale modelling. The results of the Danish case study...

  11. High-power magnetron transmitter as an RF source for superconducting linear accelerators

    CERN Document Server

    Kazakevich, Grigory; Flanagan, Gene; Marhauser, Frank; Yakovlev, Vyacheslav; Chase, Brian; Lebedev, Valeri; Nagaitsev, Sergei; Pasquinelli, Ralph; Solyak, Nikolay; Quinn, Kenneth; Wolff, Daniel; Pavlov, Viatcheslav

    2014-01-01

    A concept of a high-power magnetron transmitter for operation within a wideband control feedback loop in phase and amplitude is presented. This transmitter is proposed to drive Superconducting RF (SRF) cavities for intensity-frontier GeV-scale proton/ion linacs. The transmitter performance at the dynamic control was verified in experiments with CW, S-Band, 1 kW magnetrons. The wideband control of magnetrons, required for the superconducting linacs, was realized using the magnetrons, injection-locked by the phase-modulated signals. The capabilities of the magnetrons injection-locked by the phase-modulated signals and adequateness for feeding of SRF cavities were verified by measurements of the transfer function magnitude characteristics of single and 2-cascade magnetrons, by measurements the magnetrons phase performance and by measurements of spectra of the carrier frequency. At the ratio of power of locking signal to output power less than -13 dB (in 2-cascade scheme per magnetron, respectively) we demonstrat...

  12. IEEE-802.15.4-based low-power body sensor node with RF energy harvester.

    Science.gov (United States)

    Tran, Thang Viet; Chung, Wan-Young

    2014-01-01

    This paper proposes the design and implementation of a low-voltage and low-power body sensor node based on the IEEE 802.15.4 standard to collect electrocardiography (ECG) and photoplethysmography (PPG) signals. To achieve compact size, low supply voltage, and low power consumption, the proposed platform is integrated into a ZigBee mote, which contains a DC-DC booster, a PPG sensor interface module, and an ECG front-end circuit that has ultra-low current consumption. The input voltage of the proposed node is very low and has a wide range, from 0.65 V to 3.3 V. An RF energy harvester is also designed to charge the battery during the working mode or standby mode of the node. The power consumption of the proposed node reaches 14 mW in working mode to prolong the battery lifetime. The software is supported by the nesC language under the TinyOS environment, which enables the proposed node to be easily configured to function as an individual health monitoring node or a node in a wireless body sensor network (BSN). The proposed node is used to set up a wireless BSN that can simultaneously collect ECG and PPG signals and monitor the results on the personal computer.

  13. Simple coil-powering techniques for generating 10KA/m alternating magnetic field at multiple frequencies using 0.5KW RF power for magnetic nanoparticle hyperthermia

    Science.gov (United States)

    Piao, Daqing; Sun, Tengfei; Ranjan, Ashish

    2017-02-01

    Alternating magnetic field (AMF) configurable at a range of frequencies is a critical need for optimization of magnetic nanoparticle based hyperthermia, and for their application in targeted drug delivery. Currently, most commercial AMF devices including induction heaters operate at one factory-fixed frequency, thereby limiting customized frequency configuration required for triggered drug release at mild hyperthermia (40-42°C) and ablations (>55°C). Most AMF devices run as an inductor-capacitor resonance network that could allow AMF frequencies to be changed by changing the capacitor bank or the coil looped with it. When developing AMF inhouse, the most expensive component is usually the RF power amplifier, and arguably the most critical step of building a strong AMF field is impedance-matched coupling of RF power to the coolant-cooled AMF coil. AMF devices running at 10KA/m strength are quite common, but generating AMF at that level of field strength using RF power less than 1KW has remained challenging. We practiced a few techniques for building 10KA/m AMFs at different frequencies, by utilizing a 0.5KW 80-800KHz RF power amplifier. Among the techniques indispensable to the functioning of these AMFs, a simple cost-effective technique was the tapping methods for discretely or continuously adjusting the position of an RF-input-tap on a single-layer or the outer-layer of a multi-layer AMF coil for maximum power coupling into the AMF coil. These in-house techniques when combined facilitated 10KA/m AMF at frequencies of 88.8 KHz and higher as allowed by the inventory of capacitors using 0.5KW RF power, for testing heating of 10-15nm size magnetic particles and on-going evaluation of drug-release by low-level temperature-sensitive liposomes loaded with 15nm magnetic nanoparticles.

  14. Discharge Characteristics of Large-Area High-Power RF Ion Source for Positive and Negative Neutral Beam Injectors

    Science.gov (United States)

    Doo-Hee, Chang; Seung, Ho Jeong; Min, Park; Tae-Seong, Kim; Bong-Ki, Jung; Kwang, Won Lee; Sang Ryul, In

    2016-12-01

    A large-area high-power radio-frequency (RF) driven ion source was developed for positive and negative neutral beam injectors at the Korea Atomic Energy Research Institute (KAERI). The RF ion source consists of a driver region, including a helical antenna and a discharge chamber, and an expansion region. RF power can be transferred at up to 10 kW with a fixed frequency of 2 MHz through an optimized RF matching system. An actively water-cooled Faraday shield is located inside the driver region of the ion source for the stable and steady-state operations of high-power RF discharge. Plasma ignition of the ion source is initiated by the injection of argon-gas without a starter-filament heating, and the argon-gas is then slowly exchanged by the injection of hydrogen-gas to produce pure hydrogen plasmas. The uniformities of the plasma parameter, such as a plasma density and an electron temperature, are measured at the lowest area of the driver region using two RF-compensated electrostatic probes along the direction of the short-and long-dimensions of the driver region. The plasma parameters will be compared with those obtained at the lowest area of the expansion bucket to analyze the plasma expansion properties from the driver region to the expansion region. supported by the Ministry of Science, ICT and Future Planning of the Republic of Korea under the ITER Technology R&D Program, and National R&D Program Through the National Research Foundation of Korea (NRF) Funded by the Ministry of Science, ICT & Future Planning (NRF-2014M1A7A1A03045372)

  15. External Benefit Evaluation of Renewable Energy Power in China for Sustainability

    Directory of Open Access Journals (Sweden)

    Huiru Zhao

    2015-04-01

    Full Text Available China’s renewable energy power has developed rapidly in recent years. Evaluating the external benefits of renewable energy power can provide a reference for the Chinese government to set diverse development goals and to implement differentiated supporting policies for different renewable energy power types, which can promote their sustainable development. In this paper, a hybrid MCDM method was applied to evaluate the external benefits of China’s renewable energy power. Firstly, the impacts of renewable energy power accessing the power grid for multiple stakeholders in the electric power system were analyzed. Secondly, the external benefit evaluation index system for renewable energy power was built from the economic, social and environmental factors, based on the concept of sustainability. Then, the basic theory of the hybrid MCDM method employed in this paper was introduced in two parts: the superiority linguistic ratings and entropy weighting method for index weight determination and the fuzzy grey relation analysis for ranking alternatives. Finally, the external benefits of wind power, solar PV power and biomass power were evaluated. Taking a regional electric power system as an example, the results show that PV power has the greatest external benefit, followed by wind power and biomass power. Therefore, more policies supporting PV power should be put in place to promote the harmonious and sustainable development of the whole renewable energy power industry.

  16. RF power control for fabricating amorphous silicon nitride without Si-nanocrystals and its effect on defects and luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Seunghun [Department of Physics, University of Seoul, Seoul 130-743 (Korea, Republic of); Advanced Materials Division, Korea Research Institute of Chemical Technology (KRICT), Daejeon 305-600 (Korea, Republic of); Han, Moonsup, E-mail: mhan@uos.ac.kr [Department of Physics, University of Seoul, Seoul 130-743 (Korea, Republic of)

    2014-11-25

    Highlights: • We fabricated a-SiN{sub x} without Si-nanocrystals by using PECVD. • We investigated comprehensively the defects in a-SiN{sub x} and the relation between their defects and PL by providing energy-level diagram. • We succeeded to tune efficiently the whole range of visible luminescence with one system based material. • We conclude that RF power-control provides an efficient way to tune the color. - Abstract: We studied defect and luminescence properties of amorphous silicon nitride (a-SiN{sub x}) without silicon nanocrystals (Si-NC) fabricated by plasma-enhanced chemical vapor deposition under a controlled radio-frequency (RF) power with subsequent post-annealing. The photoluminescence (PL) intensity became stronger and the central PL peak position shifted from 2.85 eV to 1.35 eV as the applied RF power decreased from 100 W to 60 W. Through the analyses of the PL and the photoluminescence excitation (PLE) spectra we classified different kinds of defect states that each sample contains. On the basis of a further analysis of the chemical states of the Si 2p and the N 1s core-levels by X-ray photoelectron spectroscopy, we discuss the reason that the 60 W sample contains more defect states than other samples and clarify the origin of the strong luminescence observed in the 60 W sample without Si-NC fabricated at relatively low RF power. In addition, this work shows also that the RF power control could provide an efficient way to select a color or all colors for the display devices by tuning the various kinds of defects in a-SiN{sub x} thin films.

  17. A.c. Power Measurement Using Power Analyzer Associated with External Transducers. Accuracy and Uncertainty Evaluation

    Directory of Open Access Journals (Sweden)

    Marinel Popescu

    2014-09-01

    Full Text Available The development of the digital signal processors and their implementation in measuring technique has led to the manufacturing of power analyzers used as multifunction meters in industry, automation, tests and laboratory activities, monitoring and control of processes, etc. The parameters of a three-phase system can be known if the phase currents, the phase voltages and the phase difference between them can be known.A power analyzer has six inputs for currents and voltages measuring signals. The paper presents a method of determination of errors and uncertainties of electrical quantities measurement using a power analyzer associated with external transducers. The best estimation of measured quantity and uncertainty of measurement are used to report the result of measurement process.

  18. Novel Radio on Fiber Access Eliminating External Electric Power Supply at Base Station

    Institute of Scientific and Technical Information of China (English)

    Tetsuya; Miki; Katsuyasu; Kawano; Nobuo; Nakajima; Naoto; Kishi; Masaru; Miyamoto; Tetsu; Aoki

    2003-01-01

    A novel Radio On Fiber(ROF) access is proposed and demonstrated which enables the pico-cell Base Station (BS) for high-speed wireless communications to eliminate external electric power supply facilities. We demonstrated 2.4-GHz band radio signal transmission through the BS without external electric power supply. The electrical power used for BS circuit is feeded by optical power over optical fiber from central station.

  19. Power unit impedance and distance protection functions during faults in the external power grid

    Directory of Open Access Journals (Sweden)

    Marcin Lizer

    2012-12-01

    Full Text Available This paper presents the problem of the risk of an unnecessary tripping of a generation unit’s underimpedance protection functions in circumstances of generator power swings following elimination of long-lasting fault in the external power grid. The fi rst part describes typical solutions of a generator impedance protection function (21e and unit distance protection function (21s. Starting characteristics of these protection functions are shown, as well as their typical operating logics and ways of calculating their settings. Then exemplary (the most common solutions of unit under-impedance relays power swing blocking functions are described. Following this introduction, the issues of the threat of unnecessary operation of fast-tripping protection zones of 21e and 21s protection functions are described, which arises in the circumstances of generator asynchronous power swings occurring after elimination of long-lasting faults in the grid supplied by the power unit. The paper also shows that the available power swing blocking functions may not be able to correctly detect the described conditions, thus allowing the unnecessary operation of under-impedance relays. How an impedance calculation algorithm affects the impedance trajectory seen by a protection relay is also resented.

  20. 75 FR 56021 - Energy Conservation Standards for Battery Chargers and External Power Supplies: Public Meeting...

    Science.gov (United States)

    2010-09-15

    ..., and preliminary results. II. History of Standards Rulemaking for Battery Chargers and External Power... Part 430 RIN 1904-AB57 Energy Conservation Standards for Battery Chargers and External Power Supplies... establishing energy conservation standards for battery chargers (BCs) and non-Class A EPSs; the...

  1. RF rectifiers for EM power harvesting in a Deep Brain Stimulating device.

    Science.gov (United States)

    Hosain, Md Kamal; Kouzani, Abbas Z; Tye, Susannah; Kaynak, Akif; Berk, Michael

    2015-03-01

    A passive deep brain stimulation (DBS) device can be equipped with a rectenna, consisting of an antenna and a rectifier, to harvest energy from electromagnetic fields for its operation. This paper presents optimization of radio frequency rectifier circuits for wireless energy harvesting in a passive head-mountable DBS device. The aim is to achieve a compact size, high conversion efficiency, and high output voltage rectifier. Four different rectifiers based on the Delon doubler, Greinacher voltage tripler, Delon voltage quadrupler, and 2-stage charge pumped architectures are designed, simulated, fabricated, and evaluated. The design and simulation are conducted using Agilent Genesys at operating frequency of 915 MHz. A dielectric substrate of FR-4 with thickness of 1.6 mm, and surface mount devices (SMD) components are used to fabricate the designed rectifiers. The performance of the fabricated rectifiers is evaluated using a 915 MHz radio frequency (RF) energy source. The maximum measured conversion efficiency of the Delon doubler, Greinacher tripler, Delon quadrupler, and 2-stage charge pumped rectifiers are 78, 75, 73, and 76 % at -5 dBm input power and for load resistances of 5-15 kΩ. The conversion efficiency of the rectifiers decreases significantly with the increase in the input power level. The Delon doubler rectifier provides the highest efficiency at both -5 and 5 dBm input power levels, whereas the Delon quadrupler rectifier gives the lowest efficiency for the same inputs. By considering both efficiency and DC output voltage, the charge pump rectifier outperforms the other three rectifiers. Accordingly, the optimised 2-stage charge pumped rectifier is used together with an antenna to harvest energy in our DBS device.

  2. A new slip stacking RF system for a twofold power upgrade of Fermilab's Accelerator Complex

    Energy Technology Data Exchange (ETDEWEB)

    Madrak, Robyn

    2014-09-11

    Fermilab@?s Accelerator Complex has been recently upgraded, in order to increase the 120GeV proton beam power on target from about 400kW to over 700kW for NO@nA and other future intensity frontier experiments. One of the key ingredients of the upgrade is the offloading of some Main Injector synchrotron operations - beam injection and RF manipulation called ''slip stacking'' - to the 8GeV Recycler Ring, which had until recently been used only for low-intensity antiproton storage and cooling. This required construction of two new 53MHz RF systems for the slip-stacking manipulations. The cavities operate simultaneously at V_p_e_a_k@?150kV, but at slightly different frequencies (@Df=1260Hz). Their installation was completed in September 2013. This paper describes the novel solutions used in the design of the new cavities, their tuning system, and the associated high power RF system. First results showing effective operation of the RF system, beam capture and successful slip-stacking in the Recycler Ring are presented.

  3. A new slip stacking RF system for a twofold power upgrade of Fermilab's Accelerator Complex

    Energy Technology Data Exchange (ETDEWEB)

    Madrak, Robyn [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2014-05-15

    Fermilab's Accelerator Complex has been recently upgraded, in order to increase the 120 GeV proton beam power on target from about 400 kW to over 700 kW for NOvA and other future intensity frontier experiments. One of the key ingredients of the upgrade is the offloading of some Main Injector synchrotron operations - beam injection and RF manipulation called ''slip stacking'' - to the 8GeV Recycler Ring, which had until recently been used only for low-intensity antiproton storage and cooling. This required construction of two new 53 MHz RF systems for the slip-stacking manipulations. The cavities operate simultaneously at Vpeak ≲150 kV, but at slightly different frequencies (Δf=1260 Hz). Their installation was completed in September 2013. This article describes the novel solutions used in the design of the new cavities, their tuning system, and the associated high power RF system. First results showing effective operation of the RF system, beam capture and successful slip-stacking in the Recycler Ring are presented.

  4. RF Power Detector/Monitor Upgrade for the 500MHz Systems at the ALS

    Energy Technology Data Exchange (ETDEWEB)

    Baptiste, K.

    2003-05-08

    Several systems rely on the accurate and linear detection of 500 MHz signals, (the fundamental frequency of both the Booster Ring and Storage Ring) over a dynamic range in excess of 25dB. Prior to this upgrade, the detector/monitor was diode based and though this type of detector could handle the dynamic range requirement it could not do so in an accurate and linear manner. In order to meet the requirements (dynamic range greater than or equal to 25dB, accurate and linear to +-0.25dB over the range, and additional circuitry to interface to the legacy control system and interlocks), a new RF Power Detector/Monitor has been developed using two AD8361, Analog Devices Tru RMS Detectors and a fuzzy comparator, which extends the overall detector's range to twice that of the AD8361. Further information is available [www.analogedevices.com/]. Details of the design requirements and the detector/monitor's circuit as well as the performance of the detector will be presented.

  5. Thermal management of space-based, high-power solid-state RF amplifiers. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Rose, M.F.; Chow, L.C.; Johnson, J.H.

    1990-08-01

    The advanced weapons concepts envisioned by the SDIO employed a wide array of highly energetic devices, which due to inefficiencies, generate large quantities of waste heat. Power and thermal management are integrally related. In the vacuum of space, disposing of waste energy is a major problem which can contribute as much as 50% to the overall spacecraft mass and volume. The problem becomes more acute as the temperature at which the energy must be rejected is lowered. In an earlier study, thermal management issues associated with megawatt class RF microwave tubes were explored to determine if there were simple, approximately mass neutral schemes which might be adapted to dispose of the waste energy generated within a tube collector operating in space. The assumptions for that study were: (1) Tubes were in the megawatt class-70% efficient for single simple collector and 90% efficient for depressed collectors, (2) On-board, super critical hydrogen was available at a pressure of 35 bars and a temperature of 35 K. (3) The largest single event run time was 500 seconds. (4) The device would be dormant for long periods of time, be required to become active in tens of seconds followed by long periods of dormancy. (5) The only allowable effluent is hydrogen. (6) System impact must be minimal.

  6. Study on the L–H transition power threshold with RF heating and lithium-wall coating on EAST

    DEFF Research Database (Denmark)

    Chen, Leifeng; Xu, G.S.; Nielsen, Anders Henry

    2016-01-01

    The power threshold for low (L) to high (H) confinement mode transition achieved by radio-frequency (RF) heating and lithium-wall coating is investigated experimentally on EAST for two sets of walls: an all carbon wall (C) and molybdenum chamber and a carbon divertor (Mo/C). For both sets of walls......, a minimum power threshold Pthr of ~0.6 MW was found when the EAST operates in a double null (DN) divertor configuration with intensive lithium-wall coating. When operating in upper single null (USN) or lower single null (LSN), the power threshold depends on the ion ∇B drift direction. The low density...

  7. Continuous emission of keV x-rays from low-pressure, low-field, low-power-RF plasma columns and significance to mirror confinement

    Science.gov (United States)

    Jandovitz, P.; Swanson, C.; Glasser, A.; Cohen, S. A.

    2016-10-01

    We report on observations of a continuous stream of 0.8-6.0 keV x-rays emitted from cool (bulk Te 4 eV), tenuous (ne 1010 cm-3), 4-cm-diameter hydrogen or argon plasma columns generated in an axisymmetric, high-mirror-ratio, tandem mirror machine heated in one end cell by an external RF (27 MHz) antenna operating at low power, 20-600 W. The continuous emission of x-rays is evidence of the steady production of energetic electrons. The source appears to be ion-induced secondary electron emission from a floating carbon cup in the vacuum system about 2 cm from the RF antenna. The cup is charged to a high negative potential, perhaps by other secondary electrons emitted from the self-biased Pyrex vessel under the antenna. X-ray emission in the central cell increases as the mirror ratio increases, an effect we attribute to increased trapping of passing particles due to non-adiabatic scattering at the midplane of the central cell. This work was supported, in part, by DOE Contract Number DE-AC02-09CH11466.

  8. Dual-Functional On-Chip AlGaAs/GaAs Schottky Diode for RF Power Detection and Low-Power Rectenna Applications

    Directory of Open Access Journals (Sweden)

    Abdul Manaf Hashim

    2011-08-01

    Full Text Available A Schottky diode has been designed and fabricated on an n-AlGaAs/GaAs high-electron-mobility-transistor (HEMT structure. Current-voltage (I-V measurements show good device rectification, with a Schottky barrier height of 0.4349 eV for Ni/Au metallization. The differences between the Schottky barrier height and the theoretical value (1.443 eV are due to the fabrication process and smaller contact area. The RF signals up to 1 GHz are rectified well by the fabricated Schottky diode and a stable DC output voltage is obtained. The increment ratio of output voltage vs input power is 0.2 V/dBm for all tested frequencies, which is considered good enough for RF power detection. Power conversion efficiency up to 50% is obtained at frequency of 1 GHz and input power of 20 dBm with series connection between diode and load, which also shows the device’s good potential as a rectenna device with further improvement. The fabricated n-AlGaAs/GaAs Schottky diode thus provides a conduit for breakthrough designs for RF power detectors, as well as ultra-low power on-chip rectenna device technology to be integrated in nanosystems.

  9. Computation of External Quality Factors for RF Structures by Means of Model Order Reduction and a Perturbation Approach

    CERN Document Server

    Flisgen, Thomas; van Rienen, Ursula

    2016-01-01

    External quality factors are significant quantities to describe losses via waveguide ports in radio frequency resonators. The current contribution presents a novel approach to determine external quality factors by means of a two-step procedure: First, a state-space model for the lossless radio frequency structure is generated and its model order is reduced. Subsequently, a perturbation method is applied on the reduced model so that external losses are accounted for. The advantage of this approach results from the fact that the challenges in dealing with lossy systems are shifted to the reduced order model. This significantly saves computational costs. The present paper provides a short overview on existing methods to compute external quality factors. Then, the novel approach is introduced and validated in terms of accuracy and computational time by means of commercial software.

  10. A 5.2GHz, 0.5mW RF powered wireless sensor with dual on-chip antennas for implantable intraocular pressure monitoring

    KAUST Repository

    Arsalan, Muhammad

    2013-06-01

    For the first time a single chip implantable wireless sensor system for Intraocular Pressure Monitoring (IOPM) is presented. This system-on-chip (SoC) is battery-free and harvests energy from incoming RF signals. The chip is self-contained and does not require external components or bond wires to function. This 1.4mm3 SoC has separate 2.4GHz-transmit and 5.2GHz-receive antennas, an energy harvesting module, a temperature sensor, a 7-bit TIQ Flash ADC, a 4-bit RFID, a power management and control unit, and a VCO transmitter. The chip is fabricated in a standard 6-metal 0.18μm CMOS process and is designed to work with a post-processed MEMS pressure sensor. It consumes 513μW of peak power and when implanted inside the eye, it is designed to communicate with an external reader using on-off keying (OOK). © 2013 IEEE.

  11. Design of a 0.18 {mu}m CMOS multi-band compatible low power GNSS receiver RF frontend

    Energy Technology Data Exchange (ETDEWEB)

    Li Bing; Zhuang Yiqi; Long Qiang; Jin Zhao; Li Zhenrong; Jin Gang, E-mail: waxmax@126.com [Key Laboratory of the Ministry of Education for Wide Bandgap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi' an 710071 (China)

    2011-03-15

    This paper presents the design and implementation of a fully integrated multi-band RF receiver frontend for GNSS applications on L-band. A single RF signal channel with a low-IF architecture is adopted for multi-band operation on the RF section, which mainly consists of a low noise amplifier (LNA), a down-converter, polyphase filters and summing circuits. An improved cascode source degenerated LNA with a multi-band shared off-chip matching network and band switches is implemented in the first amplifying stage. Also, a re-designed wideband double balance mixer is implemented in the down conversion stage, which provides better gain, noise figure and linearity performances. Using a TSMC 0.18 {mu}m 1P4M RF CMOS process, a compact 1.27 GHz/1.575 GHz dual-band GNSS frontend is realized in the proposed low-IF topology. The measurements exhibit the gains of 45 dB and 43 dB, and noise figures are controlled at 3.35 dB and 3.9 dB of the two frequency bands, respectively. The frontend model consumes about 11.8-13.5 mA current on a 1.8 V power supply. The core occupies 1.91 x 0.53 mm{sup 2} while the total die area with ESD is 2.45 x 2.36 mm{sup 2}. (semiconductor integrated circuits)

  12. RF-MEMS for future mobile applications: experimental verification of a reconfigurable 8-bit power attenuator up to 110 GHz

    Science.gov (United States)

    Iannacci, J.; Tschoban, C.

    2017-04-01

    RF-MEMS technology is proposed as a key enabling solution for realising the high-performance and highly reconfigurable passive components that future communication standards will demand. In this work, we present, test and discuss a novel design concept for an 8-bit reconfigurable power attenuator, manufactured using the RF-MEMS technology available at the CMM-FBK, in Italy. The device features electrostatically controlled MEMS ohmic switches in order to select/deselect the resistive loads (both in series and shunt configuration) that attenuate the RF signal, and comprises eight cascaded stages (i.e. 8-bit), thus implementing 256 different network configurations. The fabricated samples are measured (S-parameters) from 10 MHz to 110 GHz in a wide range of different configurations, and modelled/simulated with Ansys HFSS. The device exhibits attenuation levels (S21) in the range from  ‑10 dB to  ‑60 dB, up to 110 GHz. In particular, S21 shows flatness from 15 dB down to 3–5 dB and from 10 MHz to 50 GHz, as well as fewer linear traces up to 110 GHz. A comprehensive discussion is developed regarding the voltage standing wave ratio, which is employed as a quality indicator for the attenuation levels. The margins of improvement at design level which are needed to overcome the limitations of the presented RF-MEMS device are also discussed.

  13. The EU as a Normative Power and the Research on External Perceptions: the Missing Link

    DEFF Research Database (Denmark)

    Larsen, Henrik

    2014-01-01

    perception offer some findings that are central for the NPE debate. This article’s argument is that the external perceptions literature points to a limited (if still identifiable) perception of the EU as a normative power depending on the geographical area. By comparison, the image of a powerful economic......In research on European foreign policy two important axes of debate have been running relatively independently of each other for more than a decade: the study of the European Union as a normative power (NPE) and the study of external perceptions of the EU. However, the studies of external...

  14. Theoretical analysis and an improvement method of the bias effect on the linearity of RF linear power amplifiers

    Institute of Scientific and Technical Information of China (English)

    Wu Tuo; Chen Hongyi; Qian Dahong

    2009-01-01

    Based on the Gummel-Poon model of BJT, the change of the DC bias as a function of the AC input signal in RF linear power amplifiers is theoretically derived, so that the linearity of different DC bias circuits can be interpreted and compared. According to the analysis results, a quantitative adaptive DC bias circuit is proposed,which can improve the linearity and efficiency. From the simulation and test results, we draw conclusions on how to improve the design of linear power amplifier.

  15. A Simulation Tool for Steady State Thermal Performance Applied to the SPL Double-Walled Tube RF Power Coupler

    CERN Document Server

    Bonomi, R

    2014-01-01

    This note reports on the study carried out to design a tool for steady-state thermal performance of the RF power coupler inside the SPL cryostat. To reduce the amount of heat penetrating into the helium bath where the cavity is placed, the main coupler is actively cooled by means of an adequate flow rate of helium gas. The knowledge of the temperature profiles and the overall thermal performance of the power coupler are fundamental for the estimation of the total heat load budget of the cryostat.

  16. 47 CFR 15.204 - External radio frequency power amplifiers and antenna modifications.

    Science.gov (United States)

    2010-10-01

    ... person shall use, manufacture, sell or lease, offer for sale or lease (including advertising for sale or lease), or import, ship, or distribute for the purpose of selling or leasing, any external radio... separate product. (1) An external radio frequency power amplifier may be marketed for individual...

  17. Low pressure and high power rf sources for negative hydrogen ions for fusion applications (ITER neutral beam injection).

    Science.gov (United States)

    Fantz, U; Franzen, P; Kraus, W; Falter, H D; Berger, M; Christ-Koch, S; Fröschle, M; Gutser, R; Heinemann, B; Martens, C; McNeely, P; Riedl, R; Speth, E; Wünderlich, D

    2008-02-01

    The international fusion experiment ITER requires for the plasma heating and current drive a neutral beam injection system based on negative hydrogen ion sources at 0.3 Pa. The ion source must deliver a current of 40 A D(-) for up to 1 h with an accelerated current density of 200 Am/(2) and a ratio of coextracted electrons to ions below 1. The extraction area is 0.2 m(2) from an aperture array with an envelope of 1.5 x 0.6 m(2). A high power rf-driven negative ion source has been successfully developed at the Max-Planck Institute for Plasma Physics (IPP) at three test facilities in parallel. Current densities of 330 and 230 Am/(2) have been achieved for hydrogen and deuterium, respectively, at a pressure of 0.3 Pa and an electron/ion ratio below 1 for a small extraction area (0.007 m(2)) and short pulses (ITER source but without extraction system, is intended to demonstrate the size scaling and plasma homogeneity of rf ion sources. The source operates routinely now. First results on plasma homogeneity obtained from optical emission spectroscopy and Langmuir probes are very promising. Based on the success of the IPP development program, the high power rf-driven negative ion source has been chosen recently for the ITER beam systems in the ITER design review process.

  18. An RF power amplifier with inter-metal-shuffled capacitor for inter-stage matching in a digital CMOS process

    Institute of Scientific and Technical Information of China (English)

    Feng Xiaoxing; Zhang Xing; Ge Binjie; Wang Xin'an

    2009-01-01

    One challenge of the implementation of fully-integrated RF power amplifiers into a deep submicro digital CMOS process is that no capacitor is available, especially no high density capacitor. To address this problem, a twostage class-AB power amplifier with inter-stage matching realized by an inter-metal coupling capacitor is designed in a 180-nm digital CMOS process. This paper compares three structures of inter-metal coupling capacitors with metal-insulator-metal (MIM) capacitor regarding their capacitor density. Detailed simulations are carried out for the leakage, the voltage dependency, the temperature dependency, and the quality factor between an inter-metal shuffled (IMS) capacitor and an MIM capacitor. Finally, an IMS capacitor is chosen to perform the inter-stage matching.The techniques are validated via the design and implement of a two-stage class-AB RF power amplifier for an UHF RFID application. The PA occupies 370 X 200 μm2 without pads in the 180-nm digital CMOS process and outputs 21.1 dBm with 40% drain efficiency and 28.1 dB power gain at 915 MHz from a single 3.3 V power supply.

  19. Secure optionally passive RFID tag or sensor with external power source and data logging

    Energy Technology Data Exchange (ETDEWEB)

    Nekoogar, Faranak; Reynolds, Matthew; Lefton, Scott; Dowla, Farid; Twogood, Richard

    2016-05-31

    A secure optionally passive RFID tag or sensor system comprises a passive RFID tag having means for receiving radio signals from at least one base station and for transmitting radio signals to at least one base station, where the tag is capable of being powered exclusively by received radio energy, and an external power and data logging device having at least one battery and electronic circuitry including a digital memory configured for storing and recalling data. The external power and data logging device has a means for powering the tag, and also has a means.

  20. Effect of Radio Frequency Power on the Physicochemical Properties of MoS{sub 2} Films Obtained by RF Magnetron Sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Park, Juyun; Kang, Yong-Cheol [Pukyong National University, Busan (Korea, Republic of)

    2016-08-15

    This paper presents the results of the fabrication and characterization of MoS{sub 2} thin films obtained at different radio frequency (RF) power using a surface profiler, a 4-point probe, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and distilled water and ethylene glycol contact angle measurements. The thickness of MoS{sub 2} thin films increased from 100 to 240 nm as the RF power increased from 100 to 200 W. The surface resistance increased with increasing RF power. The high-resolution XPS spectra indicated that Mo species with lower oxidation states formed in the MoS{sub 2} thin films at higher RF power. The ratio of Mo/S was independent of the RF power. The total surface-free energy (SFE) varied by changing the RF power. The contribution of polar SFE was greater than dispersive SFE to the total SFE for all MoS{sub 2} films. The changing propensity of polar SFE was similar to the total SFE.

  1. Detecting Low-Power RF Signals Using a Multimode Optoelectronic Oscillator and Integrated Optical Filter

    Science.gov (United States)

    2010-02-01

    output is connected to an erbium-doped fiber amplifier ( EDFA ) and the amplified signal is sent to a photodetector. Part of the detected electrical...1 dB below threshold at 1 GHz with a photocurrent of 20.2 mA. The mode spacing is 5.2 MHz, limited by the long length of fiber in the EDFA . We inject...insertion loss. The optical signal after the filter is then amplified by an EDFA and measured at an ESA. The RF gain of the different RF tones was measured

  2. An on-chip temperature compensation circuit for an InGaP/GaAs HBT RF power amplifier

    Science.gov (United States)

    Chengzhan, Li; Zhijian, Chen; Jiwei, Huang; Yongping, Wang; Chuanhui, Ma; Hanbing, Yang; Yinghao, Liao; Yong, Zhou; Bin, Liu

    2011-03-01

    A new on-chip temperature compensation circuit for a GaAs-based HBT RF amplifier applied to wireless communication is presented. The simple compensation circuit is composed of one GaAs HBT and five resistors with various values, which allow the power amplifier to achieve better thermal characteristics with a little degradation in performance. It effectively compensates for the temperature variation of the gain and the output power of the power amplifier by regulating the base quiescent bias current. The temperature compensation circuit is applied to a 3-stage integrated power amplifier for wireless communication applications, which results in an improvement in the gain variation from 4.0 to 1.1 dB in the temperature range between -20 and +80 °C.

  3. An on-chip temperature compensation circuit for an InGaP/GaAs HBT RF power amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Li Chengzhan; Chen Zhijian; Huang Jiwei; Wang Yongping; Ma Chuanhui; Yang Hanbing; Liao Yinghao; Zhou Yong; Liu Bin, E-mail: lichzh@runxinic.com [Guangzhou Runxin Information Technology Co., Ltd, Guangzhou 510663 (China)

    2011-03-15

    A new on-chip temperature compensation circuit for a GaAs-based HBT RF amplifier applied to wireless communication is presented. The simple compensation circuit is composed of one GaAs HBT and five resistors with various values, which allow the power amplifier to achieve better thermal characteristics with a little degradation in performance. It effectively compensates for the temperature variation of the gain and the output power of the power amplifier by regulating the base quiescent bias current. The temperature compensation circuit is applied to a 3-stage integrated power amplifier for wireless communication applications, which results in an improvement in the gain variation from 4.0 to 1.1 dB in the temperature range between -20 and +80 {sup 0}C. (semiconductor integrated circuits)

  4. High-power magnetron transmitter as an RF source for the electron collider ring of the MEIC facility

    CERN Document Server

    Kazakevich, G

    2014-01-01

    A novel concept of high-power transmitters utilizing the Continuous Wave (CW) magnetrons, frequency-locked by phase-modulated signals has been proposed to compensate energy losses caused by Synchrotron Radiation (SR) in the electron ring of the MEIC facility. At operating frequency of about 750 MHz the SR losses are ~2 MW. They can be compensated by some number of Superconducting RF (SRF) cavities at the feeding power of about 100-200 kW per cavity. A high-power CW transmitters, based on magnetrons, frequency-locked by phase-modulated signal, allowing a wide-band control in phase and power, and associated with a wide-band closed feedback loop are proposed to feed the SRF cavities to compensate the SR losses of the electron beam in the MEIC collider electron ring.

  5. An on-chip temperature compensation circuit for an InGaP/GaAs HBT RF power amplifier

    Institute of Scientific and Technical Information of China (English)

    Li Chengzhan; Chen Zhijian; Huang Jiwei; Wang Yongping; Ma Chuanhui; Yang Hanbing; Liao Yinghao; Zhou Yong; Liu Bin

    2011-01-01

    A new on-chip temperature compensation circuit for a GaAs-based HBT RF amplifier applied to wireless communication is presented.The simple compensation circuit is composed of one GaAs HBT and five resistors with various values,which allow the power amplifier to achieve better thermal characteristics with a little degradation in performance.It effectively compensates for the temperature variation of the gain and the output power of the power amplifier by regulating the base quiescent bias current.The temperature compensation circuit is applied to a 3-stage integrated power amplifier for wireless communication applications,which results in an improvement in the gain variation from 4.0 to 1.1 dB in the temperature range between -20 and +80 ℃.

  6. Reliability of high power laser diodes with external optical feedback

    Science.gov (United States)

    Bonsendorf, Dennis; Schneider, Stephan; Meinschien, Jens; Tomm, Jens W.

    2016-03-01

    Direct diode laser systems gain importance in the fields of material processing and solid-state laser pumping. With increased output power, also the influence of strong optical feedback has to be considered. Uncontrolled optical feedback is known for its spectral and power fluctuation effects, as well as potential emitter damage. We found that even intended feedback by use of volume Bragg gratings (VBG) for spectral stabilization may result in emitter lifetime reduction. To provide stable and reliable laser systems design, guidelines and maximum feedback ratings have to be found. We present a model to estimate the optical feedback power coupled back into the laser diode waveguide. It includes several origins of optical feedback and wide range of optical elements. The failure thresholds of InGaAs and AlGaAs bars have been determined not only at standard operation mode but at various working points. The influence of several feedback levels to laser diode lifetime is investigated up to 4000h. The analysis of the semiconductor itself leads to a better understanding of the degradation process by defect spread. Facet microscopy, LBIC- and electroluminescence measurements deliver detailed information about semiconductor defects before and after aging tests. Laser diode protection systems can monitor optical feedback. With this improved understanding, the emergency shutdown threshold can be set low enough to ensure laser diode reliability but also high enough to provide better machine usability avoiding false alarms.

  7. Traveling Wave Tube (TVT) RF Power Combining Demonstration for use in the Jupiter Icy Moons Orbiter (JIMO)

    Science.gov (United States)

    Downey, Joseph A.

    2004-01-01

    The Jupiter Icy Moons Orbiter (JIMO) is set to launch between the years 2012 and 2015. It will possibly utilize a nuclear reactor power source and ion engines as it travels to the moons of Jupiter. The nuclear reactor will produce hundreds of kilowatts of power for propulsion, communication and various scientific instruments. Hence, the RF amplification devices aboard will be able to operate at a higher power level and data rate. The initial plan for the communications system is for an output of 1000 watts of RF power, a data rate of at least 10 megabits a second, and a frequency of 32 GHz. A higher data rate would be ideal to fully utilize the instruments aboard JIMO. At NASA Glenn, one of our roles in the JIMO project is to demonstrate RF power combining using multiple traveling wave tubes (TWT). In order for the power of separate TWT s to be combined, the RF output waves from each must be in-phase and have the same amplitude. Since different tubes act differently, we had to characterize each tube using a Network Analyzer. We took frequency sweeps and power sweeps to characterize each tube to ensure that they will behave similarly under the same conditions. The 200 watt Dornier tubes had been optimized to run at a lower power level (120 watts) for their extensive use in the ACTS program, so we also had to experiment with adjusting the voltage settings on several internal components (helix, anode, collector) of the tubes to reach the full 200 watt potential. from the ACTS program. Phase shifters and power attenuators were placed in the waveguide circuit at the inputs to the tubes so that adjustments could be made individually to match them exactly. A magic tee was used to route and combine the amplified electromagnetic RF waves on the tube output side. The demonstration of 200 watts of combined power was successful with efficiencies greater than 90% over a 500 MHz bandwidth. The next step will be to demonstrate the use of three amplifiers using two magic tees by

  8. Comparison of External Cost of Nuclear Power Chain and Coal Power Chain in China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>The use of energy causes damage to a wide range of receptors, including human health, crops, forests, materials and natural ecosystems. Such damages are referred to as external costs or externalities, which

  9. Single-Stage Low-Power Quadrature RF Receiver Front-End: The LMV Cell

    DEFF Research Database (Denmark)

    Liscidini, Antonio; Mazzanti, Andrea; Tonietto, Riccardo;

    2006-01-01

    This paper presents the first quadrature RF receiver front-end where, in a single stage, low-noise amplifier (LNA), mixer and voltage-controlled oscillator (VCO) share the same bias current. The new structure exploits the intrinsic mixing functionality of a classical LC-tank oscillator providing...

  10. Towards low power N-Path filters for flexible RF-Channel selection

    NARCIS (Netherlands)

    Klumperink, Eric A.M.; Soer, Michiel C.M.; Struiksma, Remko E.; Vliet, van Frank E.; Nauta, Bram

    2015-01-01

    N-path filters can offer high-linearity high-Q channel selection filtering at a flexibly programmable RF center frequency, which is highly wanted for Software Defined Radio. Relying on capacitors and MOSFET switches, driven by digital non-overlapping clocks, N-path filters fit well to CMOS and benef

  11. Implementation of external hazards in Probabilistic Safety Assessment for nuclear power plants

    Science.gov (United States)

    Kumar, Manorma; Klug, Joakim; Raimond, Emmanuel

    2015-04-01

    The paper will focus on the discussion on implementation of external hazards in the probabilistic safety assessment (PSA) methods for the extreme external hazards mainly focused on Seismic, Flooding, Meteorological Hazards (e.g. Storm, Extreme temperature, snow pack), Biological infestation, Lightening hazards, Accidental Aircraft crash and man- made hazards including natural external fire and external explosion. This will include discussion on identification of some good practices on the implementation of external hazards in Level 1 PSA, with a perspective of development of extended PSA and introduction of relevant modelling for external hazards in an existing Level 1 PSA. This paper is associated to the European project ASAMPSAE (www.asampsa.eu) which gathers more than 30 organizations (industry, research, safety control) from Europe, US and Japan and which aims at identifying some meaningful practices to extend the scope and the quality of the existing probabilistic safety analysis developed for nuclear power plants.

  12. Modular externally-powered system for limb prostheses

    Energy Technology Data Exchange (ETDEWEB)

    Seamone, W.; Hoshall, C.H.; Schmeisser, G.

    Many upper limb amputees especially those who have sustained high level amputations of injury to remaining portions of the body, are unable to use conventional prosthetic devices effectively. In an effort to help the more severely handicapped amputees and those who may for other reasons require capabilities that standard prostheses cannot provide, the Applied Physics Laboratory, in conjunction with the Johns Hopkins Medical Institutions, has developed a prosthetic system which is powered by rechargeable batteries. The amputee need supply only a control signal. This article describes the concept which is now being evaluated with the aid of amputee subjects, and discusses results obtained to data in field tests.

  13. Social responsible communication of nuclear power plant with external stakeholders

    Energy Technology Data Exchange (ETDEWEB)

    Simoncic, Milan [Nuclear Power Plant Krsko (Slovenia); Zurga, Gordana [Faculty of Organisation Studies in Novo Mesto (Slovenia)

    2016-11-15

    Implications that nuclear technology brings to common physical and social environment, are on daily lists of questions that stakeholders address to owners and operators of nuclear power plants. In this respect, stakeholders expect and demand narrow and explicit answers to concrete questions set. We claim that the acceptability of the NPP in the society can be achieved and maintained also through active communication and trust building between NPP and its stakeholders. A research in this respect was conducted on case of the Krsko NPP, Slovenia. Some institutional and international implications are presented, as well as possible areas for further investigation and research.

  14. Optimum Heart Rate to Minimize Pulsatile External Cardiac Power

    Science.gov (United States)

    Pahlevan, Niema; Gharib, Morteza

    2011-11-01

    The workload on the left ventricle is composed of steady and pulsatile components. Clinical investigations have confirmed that an abnormal pulsatile load plays an important role in the pathogenesis of left ventricular hypertrophy (LVH) and progression of LVH to congestive heart failure (CHF). The pulsatile load is the result of the complex dynamics of wave propagation and reflection in the compliant arterial vasculature. We hypothesize that aortic waves can be optimized to reduce the left ventricular (LV) pulsatile load. We used an in-vitro experimental approach to investigate our hypothesis. A unique hydraulic model was used for in-vitro experiments. This model has physical and dynamical properties similar to the heart-aorta system. Different compliant models of the artificial aorta were used to test the hypothesis under various aortic rigidities. Our results indicate that: i) there is an optimum heart rate that minimizes LV pulsatile power (this is in agreement with our previous computational study); ii) introducing an extra reflection site at the specific location along the aorta creates constructive wave conditions that reduce the LV pulsatile power.

  15. Multiple external hazards compound level 3 PSA methods research of nuclear power plant

    Science.gov (United States)

    Wang, Handing; Liang, Xiaoyu; Zhang, Xiaoming; Yang, Jianfeng; Liu, Weidong; Lei, Dina

    2017-01-01

    2011 Fukushima nuclear power plant severe accident was caused by both earthquake and tsunami, which results in large amount of radioactive nuclides release. That accident has caused the radioactive contamination on the surrounding environment. Although this accident probability is extremely small, once such an accident happens that is likely to release a lot of radioactive materials into the environment, and cause radiation contamination. Therefore, studying accidents consequences is important and essential to improve nuclear power plant design and management. Level 3 PSA methods of nuclear power plant can be used to analyze radiological consequences, and quantify risk to the public health effects around nuclear power plants. Based on multiple external hazards compound level 3 PSA methods studies of nuclear power plant, and the description of the multiple external hazards compound level 3 PSA technology roadmap and important technical elements, as well as taking a coastal nuclear power plant as the reference site, we analyzed the impact of off-site consequences of nuclear power plant severe accidents caused by multiple external hazards. At last we discussed the impact of off-site consequences probabilistic risk studies and its applications under multiple external hazards compound conditions, and explained feasibility and reasonableness of emergency plans implementation.

  16. External costs of silicon carbide fusion power plants compared to other advanced generation technologies

    Energy Technology Data Exchange (ETDEWEB)

    Lechon, Y. E-mail: yolanda.lechon@ciemat.es; Cabal, H.; Saez, R.M.; Hallberg, B.; Aquilonius, K.; Schneider, T.; Lepicard, S.; Ward, D.; Hamacher, T.; Korhonen, R

    2003-09-01

    This study was performed in the framework of the Socio-Economic Research on Fusion (SERF3), which is jointly conducted by Euratom and the fusion associations. Assessments of monetarized external impacts of the fusion fuel-cycle were previously performed (SERF1 and SERF2). Three different power plant designs were studied, with the main difference being the structural materials and cooling system used. In this third phase of the SERF project the external costs of three additional fusion power plant models using silicon carbide as structural material have been analysed. A comparison with other advanced generation technologies expected to be in use around 2050, when the first fusion power plant would be operative, has also been performed. These technologies include advanced fossil technologies, such as Natural Gas Combined Cycle, Pressurised Fluidised Bed Combustion and Integrated Gasification Combined Cycle with carbon sequestration technologies; fuel cells and renewable technologies including geothermal energy, wind energy and photovoltaic systems with energy storage devices. Fusion power plants using silicon carbide as structural material have higher efficiencies than plants using steel and this fact has a very positive effect on the external costs per kW h. These external costs are in the lowest range of the external costs of advanced generation technologies indicating the outstanding environmental performance of fusion power.

  17. Savings Potential of ENERGY STAR(R) External Power Adapters andBattery Chargers

    Energy Technology Data Exchange (ETDEWEB)

    Webber, Carrie; Korn, David; Sanchez, Marla

    2007-02-28

    External power adapters may lose 10 to 70 percent of theenergy they consume, dissipated as heat rather than converted into usefulenergy. Battery charging systems have more avenues for losses: inaddition to power conversion losses, power is consumed by the chargingcircuitry, and additional power may be needed after the battery is fullcharged to balance self-discharge. In 2005, the Environmental ProtectionAgency launched a new ENERGY STAR(R) label for external power supplies(EPSs) that convert line-voltage AC electricity into low-voltage DCelectricity for certain electronic devices. The specification includedpower supplies for products with battery charging functions (e.g. laptopsand cell phones), but excluded others. In January 2006, a separatespecification was issued for battery charging systems contained primarilyin small household appliances and power tools. In addition to the ENERGYSTAR(R) label, the state of California will implement minimum energyperformance standards for EPSs in 2007, and similar standards for EPSsand battery chargers are in development at the national level.Many of theproducts covered by these policies use relatively little power and havemodest per-unit savings potential compared to conventional energyefficiency targets. But with an estimated 1.5 billion adapters and 230million battery charging systems in use in the United States, theaggregate savings potential is quite high. This paper presents estimatesof the savings potential for external power adapters and battery chargingsystems through 2025.

  18. MINIMIZATION OF IMPACTS PERTAINING TO EXTERNAL AND INTERNAL ENERGY SECURITY THREATS OF THERMAL POWER PLANTS

    Directory of Open Access Journals (Sweden)

    V. Nagornov

    2012-01-01

    Full Text Available The paper contains a classification of internal and external threats for thermal power plants and recommendations on minimization of these risks. A set of concrete measures aimed at ensuring TPP energy security has been presented in the paper. The system comprises preventive measures aimed at reducing the possibilities of emergence and implementation of internal and external threats. The system also presupposes to decrease susceptibility of fuel- and energy supply systems to the threats, and application of liquidation measures that ensure elimination of emergency situation consequences and restoration of the conditions concerning fuel- and power supply to consumers.

  19. Design and High Power Testing of 52.809 MHz RF Cavities for Slip Stacking in the Fermilab Recycler

    CERN Document Server

    Madrak, R

    2014-01-01

    For NOvA and future experiments requiring high intensity proton beams, Fermilab is in the process of upgrading the existing accelerator complex for increased proton production. One such improvement is to reduce the Main Injector cycle time, by performing slip stacking, previously done in the Main Injector, in the now repurposed Recycler Ring. Recycler slip stacking requires two new RF cavities operating at slightly different frequencies (df = 1260Hz). These are copper, coaxial, quarter wave cavities with R/Q =13 ohms. They operate at a peak gap voltage of 150 kV with 150 kW peak drive power (60% duty factor), and are resonant at 52.809 MHz with a 10 kHz tuning range. Two have been completed and installed. The design, high power test results, and status of the cavities are presented.

  20. Amorphous silicon carbon films prepared by hybrid plasma enhanced chemical vapor/sputtering deposition system: Effects of r.f. power

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Nur Maisarah Abdul, E-mail: nurmaisarahrashid@gmail.com [Low Dimensional Materials Research Centre, Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Ritikos, Richard; Othman, Maisara; Khanis, Noor Hamizah; Gani, Siti Meriam Ab. [Low Dimensional Materials Research Centre, Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Muhamad, Muhamad Rasat [Chancellery Office, Multimedia University, Jalan Multimedia, 63100 Cyberjaya, Selangor (Malaysia); Rahman, Saadah Abdul, E-mail: saadah@um.edu.my [Low Dimensional Materials Research Centre, Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Chancellery Office, Multimedia University, Jalan Multimedia, 63100 Cyberjaya, Selangor (Malaysia)

    2013-02-01

    Silicon carbon films were deposited using a hybrid radio frequency (r.f.) plasma enhanced chemical vapor deposition (PECVD)/sputtering deposition system at different r.f. powers. This deposition system combines the advantages of r.f. PECVD and sputtering techniques for the deposition of silicon carbon films with the added advantage of eliminating the use of highly toxic silane gas in the deposition process. Silicon (Si) atoms were sputtered from a pure amorphous silicon (a-Si) target by argon (Ar) ions and carbon (C) atoms were incorporated into the film from C based growth radicals generated through the discharge of methane (CH{sub 4}) gas. The effects of r.f. powers of 60, 80, 100, 120 and 150 W applied during the deposition process on the structural and optical properties of the films were investigated. Raman spectroscopic studies showed that the silicon carbon films contain amorphous silicon carbide (SiC) and amorphous carbon (a-C) phases. The r.f. power showed significant influence on the C incorporation in the film structure. The a-C phases became more ordered in films with high C incorporation in the film structure. These films also produced high photoluminescence emission intensity at around 600 nm wavelength as a result of quantum confinement effects from the presence of sp{sup 2} C clusters embedded in the a-SiC and a-C phases in the films. - Highlights: ► Effects of radio frequency (r.f.) power on silicon carbon (SiC) films were studied. ► Hybrid plasma enhanced chemical vapor deposition/sputtering technique was used. ► r.f. power influences C incorporation in the film structure. ► High C incorporation results in higher ordering of the amorphous C phase. ► These films produced high photoluminescence emission intensity.

  1. Adaptation to high current using low external resistances eliminates power overshoot in microbial fuel cells

    KAUST Repository

    Hong, Yiying

    2011-10-01

    One form of power overshoot commonly observed with mixed culture microbial fuel cells (MFCs) is doubling back of the power density curve at higher current densities, but the reasons for this type of overshoot have not been well explored. To investigate this, MFCs were acclimated to different external resistances, producing a range of anode potentials and current densities. Power overshoot was observed for reactors acclimated to higher (500 and 5000. Ω) but not lower (5 and 50. Ω) resistances. Acclimation of the high external resistance reactors for a few cycles to low external resistance (5. Ω), and therefore higher current densities, eliminated power overshoot. MFCs initially acclimated to low external resistances exhibited both higher current in cyclic voltammograms (CVs) and higher levels of redox activity over a broader range of anode potentials (-0.4 to 0. V; vs. a Ag/AgCl electrode) based on first derivative cyclic voltammetry (DCV) plots. Reactors acclimated to higher external resistances produced lower current in CVs, exhibited lower redox activity over a narrower anode potential range (-0.4 to -0.2. V vs. Ag/AgCl), and failed to produce higher currents above ∼-0.3. V (vs. Ag/AgCl). After the higher resistance reactors were acclimated to the lowest resistance they also exhibited similar CV and DCV profiles. Our findings show that to avoid overshoot, prior to the polarization and power density tests the anode biofilm must adapt to low external resistances to be capable of higher currents. © 2011 Elsevier B.V.

  2. Design, construction and operational results of the IGBT controlled solid state modulator high voltage power supply used in the high power RF systems of the Low Energy Demonstration Accelerator of the accelerator production of tritium (APT) project

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, J.T. III; Rees, D.; Przeklasa, R.S. [Los Alamos National Lab., NM (United States); Scott, M.C. [Continental Electronics Corp., Dallas, TX (United States)

    1998-12-31

    The 1700 MeV, 100 mA Accelerator Production of Tritium (APT) Proton Linac will require 244 1 MW, continuous wave RF systems. 1 MW continuous wave klystrons are used as the RF source and each klystron requires 95 kV, 17 A of beam voltage and current. The cost of the DC power supplies is the single largest percentage of the total RF system cost. Power supply reliability is crucial to overall RF system availability and AC to DC conversion efficiency affects the operating cost. The Low Energy Demonstration Accelerator (LEDA) being constructed at Los Alamos National Laboratory (LANL) will serve as the prototype and test bed for APT. The design of the RF systems used in LEDA is driven by the need to field test high efficiency systems with extremely high reliability before APT is built. The authors present a detailed description and test results of one type of advanced high voltage power supply system using Insulated Gate Bipolar Transistors (IGBTs) that has been used with the LEDA High Power RF systems. The authors also present some of the distinctive features offered by this power supply topology, including crowbarless tube protection and modular construction which allows graceful degradation of power supply operation.

  3. Internal and external spatial attention examined with lateralized EEG power spectra.

    Science.gov (United States)

    Van der Lubbe, Rob H J; Bundt, Carsten; Abrahamse, Elger L

    2014-10-02

    Several authors argued that retrieval of an item from visual short term memory (internal spatial attention) and focusing attention on an externally presented item (external spatial attention) are similar. Part of the neuroimaging support for this view may be due to the employed experimental procedures. Furthermore, as internal spatial attention may have a more induced than evoked nature some effects may not have been visible in event related analyses of the electroencephalogram (EEG), which limits the possibility to demonstrate differences. In the current study, a colored frame cued which stimulus, one out of four presented in separate quadrants, required a response, which depended on the form of the cued stimulus (circle or square). Importantly, the frame occurred either before (precue), simultaneously with (simultaneous cue), or after the stimuli (postcue). The precue and simultaneous cue condition both concern external attention, while the postcue condition implies the involvement of internal spatial attention. Event-related lateralizations (ERLs), reflecting evoked effects, and lateralized power spectra (LPS), reflecting both evoked and induced effects, were determined. ERLs revealed a posterior contralateral negativity (PCN) only in the precue condition. LPS analyses on the raw EEG showed early increased contralateral theta power at posterior sites and later increased ipsilateral alpha power at occipito-temporal sites in all cue conditions. Responses were faster when the internally or externally attended location corresponded with the required response side than when not. These findings provide further support for the view that internal and external spatial attention share their underlying mechanism.

  4. Power-efficient III-V/silicon external cavity DBR lasers.

    Science.gov (United States)

    Zilkie, A J; Seddighian, P; Bijlani, B J; Qian, W; Lee, D C; Fathololoumi, S; Fong, J; Shafiiha, R; Feng, D; Luff, B J; Zheng, X; Cunningham, J E; Krishnamoorthy, A V; Asghari, M

    2012-10-08

    We report the design and characterization of external-cavity DBR lasers built with a III-V-semiconductor reflective-SOA with spot-size converter edge-coupled to SOI waveguides containing Bragg grating mirrors. The un-cooled lasers have wall-plug-efficiencies of up to 9.5% at powers of 6 mW. The lasers are suitable for making power efficient, hybrid WDM transmitters in a CMOS-compatible SOI optical platform.

  5. The potential impact of externalities considerations on the market for biomass power technologies

    Energy Technology Data Exchange (ETDEWEB)

    Swezey, B.G.; Porter, K.L.; Feher, J.S.

    1994-02-01

    This study assesses the current status of externalities considerations--nonmarket costs and benefits--in state and utility electricity resource planning processes and determines how externalities considerations might help or hinder the development of biomass power plants. It provides an overview of biomass resources and technologies, including their market status and environmental impacts; reviews the current treatment of externalities in the states; and documents the perspectives of key utility, regulatory, and industry representatives concerning externalities considerations. The authors make the following recommendations to the biomass industry: (1) the wood and agricultural waste industries should work toward having states and utilities recognize that wood and agricultural waste are greenhouse gas neutral resources because of carbon sequestration during growth; (2) the biomass industry should emphasize nonenvironmental benefits such as economic development and job creation; and (3) the biomass industry should pursue and support efforts to establish renewable energy set-asides or ``green`` requests for proposals.

  6. The potential impact of externalities considerations on the market for biomass power technologies

    Science.gov (United States)

    Swezey, B. G.; Porter, K. L.; Feher, J. S.

    1994-02-01

    This study assesses the current status of externalities considerations--nonmarket costs and benefits--in state and utility electricity resource planning processes and determines how externalities considerations might help or hinder the development of biomass power plants. It provides an overview of biomass resources and technologies, including their market status and environmental impacts; reviews the current treatment of externalities in the states; and documents the perspectives of key utility, regulatory, and industry representatives concerning externalities considerations. The authors make the following recommendations to the biomass industry: (1) the wood and agricultural waste industries should work toward having states and utilities recognize that wood and agricultural waste are greenhouse gas neutral resources because of carbon sequestration during growth; (2) the biomass industry should emphasize nonenvironmental benefits such as economic development and job creation; and (3) the biomass industry should pursue and support efforts to establish renewable energy set-asides or 'green' requests for proposals.

  7. The impact of external optical feedback on the degradation behavior of high-power diode lasers

    DEFF Research Database (Denmark)

    Hempel, Martin; Chi, Mingjun; Petersen, Paul Michael;

    2013-01-01

    The impact of external feedback on high-power diode laser degradation is studied. For this purpose early stages of gradual degradation are prepared by accelerated aging of 808-nm-emitting AlGaAs-based devices. While the quantum well that actually experiences the highest total optical load remains...... unaffected, severe impact is observed to the cladding layers and the waveguide. Consequently hardening of diode lasers for operation under external optical feedback must necessarily involve claddings and waveguide, into which the quantum well is embedded.......The impact of external feedback on high-power diode laser degradation is studied. For this purpose early stages of gradual degradation are prepared by accelerated aging of 808-nm-emitting AlGaAs-based devices. While the quantum well that actually experiences the highest total optical load remains...

  8. Use of two-axis joystick for control of externally powered shoulder disarticulation prostheses

    Directory of Open Access Journals (Sweden)

    Robert D. Lipschutz, BSME, CP

    2011-07-01

    Full Text Available We explored a new method for simple and accurate control of shoulder movement for externally powered shoulder disarticulation prostheses with a two-axis joystick. We tested 10 subjects with intact shoulders and arms to determine the average amount of shoulder motion and force available to control an electronic input device. We then applied this information to two different input strategies to examine their effectiveness: (1 a traditional rocker potentiometer and a pair of force-sensing resistors and (2 a two-axis joystick. Three nondisabled subjects and two subjects with shoulder disarticulation amputations attempted to control an experimental externally powered shoulder using both control strategies. Two powered arms were tested, one with powered flexion/extension and humeral rotation and one with powered flexion/extension and adduction/abduction. Overwhelmingly, the subjects preferred the joystick control, because it was more intuitively linked with their shoulder movement. Additionally, two motions (one in each axis could be controlled simultaneously. This pilot study provides valuable insight into an effective means of controlling high-level, externally powered prostheses with a two-axis joystick.

  9. Collective Evidence for Inverse Compton Emission from External Photons in High-Power Blazars

    Science.gov (United States)

    Meyer, Eileen T.; Fossati, Giovanni; Georganopoulos, Markos; Lister, Matthew L.

    2012-01-01

    We present the first collective evidence that Fermi-detected jets of high kinetic power (L(sub kin)) are dominated by inverse Compton emission from upscattered external photons. Using a sample with a broad range in orientation angle, including radio galaxies and blazars, we find that very high power sources (L(sub kin) > 10(exp 45.5) erg/s) show a significant increase in the ratio of inverse Compton to synchrotron power (Compton dominance) with decreasing orientation angle, as measured by the radio core dominance and confirmed by the distribution of superluminal speeds. This increase is consistent with beaming expectations for external Compton (EC) emission, but not for synchrotron self Compton (SSC) emission. For the lowest power jets (L(sub kin) photon fields. Coupled with the evidence that jet power is linked to the jet speed, this finding suggests that external photon fields become the dominant source of seed photons in the jet comoving frame only for the faster and therefore more powerful jets.

  10. Use of two-axis joystick for control of externally powered shoulder disarticulation prostheses.

    Science.gov (United States)

    Lipschutz, Robert D; Lock, Blair; Sensinger, Jonathon; Schultz, Aimee E; Kuiken, Todd A

    2011-01-01

    We explored a new method for simple and accurate control of shoulder movement for externally powered shoulder disarticulation prostheses with a two-axis joystick. We tested 10 subjects with intact shoulders and arms to determine the average amount of shoulder motion and force available to control an electronic input device. We then applied this information to two different input strategies to examine their effectiveness: (1) a traditional rocker potentiometer and a pair of force-sensing resistors and (2) a two-axis joystick. Three nondisabled subjects and two subjects with shoulder disarticulation amputations attempted to control an experimental externally powered shoulder using both control strategies. Two powered arms were tested, one with powered flexion/extension and humeral rotation and one with powered flexion/extension and adduction/abduction. Overwhelmingly, the subjects preferred the joystick control, because it was more intuitively linked with their shoulder movement. Additionally, two motions (one in each axis) could be controlled simultaneously. This pilot study provides valuable insight into an effective means of controlling high-level, externally powered prostheses with a two-axis joystick.

  11. Degradation Processes in High-Power Diode Lasers under External Optical Feedback

    DEFF Research Database (Denmark)

    Tomm, Jens. W.; Hempel, Martin; Petersen, Paul Michael;

    2013-01-01

    The effect of moderate external feedback on the gradual degradation of 808 nm emitting AlGaAs-based high-power broad-area diode lasers is analyzed. Eventually the quantum well that actually experiences the highest total optical load remains unaffected by the aging, while severe impact...

  12. High Power RF Induced Thermal Fatigue in the High Gradient CLIC Accelerating Structures

    CERN Document Server

    Arnau-Izquierdo, G; Heikkinen, S; Neupert, N; Wuensch, W

    2007-01-01

    The need for high accelerating gradients for the CLIC (Compact Linear Collider) imposes considerable constraints on the materials of the accelerating structures. The surfaces exposed to high pulsed RF (Radio Frequency) currents are subjected to cyclic thermal stresses possibly resulting in surface break up by fatigue. Various high strength alloys from the group of high conductivity copper alloys have been selected and have been tested in different states, with different surface treatments and in different stress ratios. Low to medium cycle fatigue data (up to 108 cycles) of fully compressive surface thermal stresses has been collected by means of a pulsed laser surface heating apparatus. The surface damage has been characterized by SEM observations and roughness measurements. High cycle fatigue data, up to 7x1010 cycles, of varying stress ratio has been collected in high frequency bulk fatigue tests using an ultrasonic apparatus. Up-to-date results from these experiments are presented.

  13. A Fully Integrated RF-Powered Contact Lens With a Single Element Display.

    Science.gov (United States)

    Pandey, J; Yu-Te Liao; Lingley, Andrew; Mirjalili, R; Parviz, B; Otis, B

    2010-12-01

    We present progress toward a wirelessly-powered active contact lens comprised of a transparent polymer substrate, loop antenna, power harvesting IC, and micro-LED. The fully integrated radio power harvesting and power management system was fabricated in a 0.13 μm CMOS process with a total die area of 0.2 mm(2). It utilizes a small on-chip capacitor for energy storage to light up a micro-LED pixel. We have demonstrated wireless power transfer at 10 cm distance using the custom IC and on-lens antenna.

  14. 2.5 GHz integrated graphene RF power amplifier on SiC substrate

    Science.gov (United States)

    Hanna, T.; Deltimple, N.; Khenissa, M. S.; Pallecchi, E.; Happy, H.; Frégonèse, S.

    2017-01-01

    In this work, we report the design of 2.5 GHz integrated power amplifier based on a graphene FET fabricated with thermal deposition on SiC. In this first large signal study of graphene radiofrequency power amplifiers, a power gain of 8.9 dB is achieved, the maximum reported output power and power added efficiency are 5.1 dBm and 2.2% respectively. Furthermore, graphene and Si CMOS amplifiers are compared; conclusions are drawn towards the technology enhancements to optimize the amplifiers figures of merit.

  15. Effects of discharge power on the structural and optical properties of TGZO thin films prepared by RF magnetron sputtering technique

    Science.gov (United States)

    Gu, Jin-hua; Lu, Zhou; Zhong, Zhi-you; Long, Lu; Long, Hao

    2016-05-01

    The transparent semiconductors of Ti and Ga-incorporated ZnO (TGZO) thin films were prepared by radio frequency (RF) magnetron sputtering onto glass substrates. The effects of discharge power on the physical properties of thin films are studied. Experimental results show that all nanocrystalline TGZO thin films possess preferential orientation along the (002) plane. The discharge power significantly affects the crystal structure and optical properties of thin films. When the discharge power is 200 W, the TGZO thin film has the optimal crystalline quality and optical properties, with the narrowest full width at half-maximum ( FWHM) of 1.76×10-3 rad, the largest average grain size of 82.4 nm and the highest average transmittance of 84.3% in the visible range. The optical gaps of thin films are estimated by the Tauc's relation and observed to increase firstly and then decrease with the increase of the discharge power. In addition, the optical parameters, including refractive index, extinction coefficient, dielectric function and dissipation factor of the thin films, are determined by optical characterization methods. The dispersion behavior of the refractive index is also analyzed using the Sellmeier's dispersion model.

  16. A high-efficiency, low-noise power solution for a dual-channel GNSS RF receiver

    Science.gov (United States)

    Jian, Shi; Taishan, Mo; Jianlian, Le; Yebing, Gan; Chengyan, Ma; Tianchun, Ye

    2012-08-01

    A high-efficiency low-noise power solution for a dual-channel GNSS RF receiver is presented. The power solution involves a DC—DC buck converter and a followed low-dropout regulator (LDO). The pulse-width-modulation (PWM) control method is adopted for better noise performance. An improved low-power high-frequency PWM control circuit is proposed, which halves the average quiescent current of the buck converter to 80 μA by periodically shutting down the OTA. The size of the output stage has also been optimized to achieve high efficiency under a light load condition. In addition, a novel soft-start circuit based on a current limiter has been implemented to avoid inrush current. Fabricated with commercial 180-nm CMOS technology, the DC—DC converter achieves a peak efficiency of 93.1% under a 2 MHz working frequency. The whole receiver consumes only 20.2 mA from a 3.3 V power supply and has a noise figure of 2.5 dB.

  17. Study on the L-H transition power threshold with RF heating and lithium-wall coating on EAST

    Science.gov (United States)

    Chen, L.; Xu, G. S.; Nielsen, A. H.; Gao, W.; Duan, Y. M.; Liu, H. Q.; Wang, L.; Li, M. H.; Wang, M.; Zhang, X. J.; Chen, R.; Wang, H. Q.; Sun, Z.; Ding, S. Y.; Yan, N.; Liu, S. C.; Shao, L. M.; Zhang, W.; Hu, G. H.; Li, J.; Zhang, L.; Wan, B. N.; the EAST Team

    2016-05-01

    The power threshold for low (L) to high (H) confinement mode transition achieved by radio-frequency (RF) heating and lithium-wall coating is investigated experimentally on EAST for two sets of walls: an all carbon wall (C) and molybdenum chamber and a carbon divertor (Mo/C). For both sets of walls, a minimum power threshold P thr of ~0.6 MW was found when the EAST operates in a double null (DN) divertor configuration with intensive lithium-wall coating. When operating in upper single null (USN) or lower single null (LSN), the power threshold depends on the ion  ∇B drift direction. The low density dependence of the L-H power threshold, namely an increase below a minimum density, was identified in the Mo/C wall for the first time. For the C wall only the single-step L-H transition with limited injection power is observed whereas also the so-called dithering L-H transition is observed in the Mo/C wall. The dithering behaves distinctively in a USN, DN and LSN configuration, suggesting the divertor pumping capability is an important ingredient in this transition since the internal cryopump is located underneath the lower divertor. Depending on the chosen divertor configuration, the power across the separatrix P loss increases with neutral density near the lower X-point in EAST with the Mo/C wall, consistent with previous results in the C wall (Xu et al 2011 Nucl. Fusion 51 072001). These findings suggest that the edge neutral density, the ion  ∇B drift as well as the divertor pumping capability play important roles in the L-H power threshold and transition behaviour.

  18. An analytical model for the drain-source breakdown voltage of RF LDMOS power transistors with a Faraday shield

    Institute of Scientific and Technical Information of China (English)

    Zhang Wenmin; Zhang Wei; Fu Jun; Wang Yudong

    2012-01-01

    An analytical model for the drain-source breakdown voltage of an RF LDMOS power transistor with a Faraday shield is derived on the basis of the solution of the 2D Poisson equation in a p-type epitaxial layer,as well as an n-type drift region by means of parabolic approximation of electrostatic potential.The model captures the influence of the p-type epitaxial layer doping concentration on the breakdown voltage,compared with the previously reported model,as well as the effect of the other device parameters.The analytical model is validated by comparing with a numerical device simulation and the measured characteristics of LDMOS transistors.Based on the model,optimization of LDMOS device parameters to achieve proper trade-off between the breakdown voltage and other characteristic parameters such as on-resistance and feedback capacitance is analyzed.

  19. Technology development of RF MEMS switches on printed circuit boards

    Science.gov (United States)

    Chang, Hung-Pin

    Today, some engineers have shifted their focus on the micro-electro-mechanical system (MEMS) to pursue better technological advancements. Recent development in RF MEMS technologies have lead to superior switch characteristics, i.e., very low insertion loss, very low power requirements, and high isolation comparing to the conventional semiconductor devices. This success has promised the potential of MEMS to revolutionize RF and microwave system implementation for the next generation of communication applications. However, RF MEMS switches integrated monolithically with various RF functional components on the same substrate to create multifunctional and reconfigurable complete communication systems remains to be a challenge research topic due to the concerns of the high cost of packaging process and the high cost of RF matching requirements in module board implementation. Furthermore, the fabrication of most RF MEMS switches requires thickness control and surface planarization of wide metal lines prior to deposition of a metal membrane bridge, which poses a major challenge to manufacturability. To ease the fabrication of RF MEMS switches and to facilitate their integration with other RF components such as antennas, phase delay lines, tunable filters, it is imperative to develop a manufacturable RF MEMS switch technology on a common substrate housing all essential RF components. Development of a novel RF MEMS technology to build a RF MEMS switch and provide a system-level packaging on microwave laminated printed circuit boards (PCBs) are proposed in this dissertation. Two key processes, high-density inductively coupled plasma chemical vapor deposition (HDICP CVD) for low temperature dielectric deposition, and compressive molding planarization (COMP) for the temporary sacrificial polymer planarization have been developed for fabricating RF MEMS switches on PCBs. Several membrane-type capacitive switches have been fabricated showing excellent RF performance and dynamic

  20. Wideband high efficiency CMOS envelope amplifiers for 4G LTE handset envelope tracking RF power amplifiers

    OpenAIRE

    Hassan, Muhammad

    2012-01-01

    Fourth generation cellular networks offer performance similar to cable modems while allowing wide mobility. Although the use of orthogonal frequency division multiplexing in fourth generation increases its spectral efficiency but it also increases the peak-to-average power ratio of the transmitted signal. If a conventional power amplifier is used to transmit a high peak-to-average power ratio signal, then to meet the stringent linearity requirements, it will be operating 6 to 10 dB back-off f...

  1. Damage costs produced by electric power plants: an externality valuation in the Mexico City Metropolitan Area.

    Science.gov (United States)

    Macías, P; Islas, J

    2010-09-15

    This paper presents an estimate of the externalities produced in the Mexico City Metropolitan Area (MCMA) through the impacts on health caused by secondary pollutants attributed to seven electric power plants located outside this area. An original method was developed to make possible a simplified application of the impact pathway approach to estimate the damage costs in the specified area. Our estimate shows that the annual costs attributed to secondary pollutants total 71 million USD (min/max 20/258 million USD). Finally, this paper discusses basic ideas on the implications for energy policy arising from this exercise in externality valuation.

  2. The CLIC RF power source a novel scheme of two-beam acceleration for electron-positron linear colliders

    CERN Document Server

    Braun, Hans Heinrich; D'Amico, Tommaso Eric; Delahaye, Jean Pierre; Guignard, Gilbert; Johnson, C D; Millich, Antonio; Pearce, Peter; Riche, A J; Rinolfi, Louis; Ruth, Ronald D; Schulte, Daniel; Thorndahl, Lars; Valentini, M; Wilson, Ian H; Wuensch, Walter; CERN. Geneva

    1998-01-01

    We discuss a new approach to two-beam acceleration. The energy for RF production is initially stored in a long-pulse electron beam which is efficiently accelerated to about 1.2 GeV by a fully loaded conventional, low-frequency (approx. 1 GHz) linac. The beam pulse length is twice the length of the high-gradient linac. Segments of this long pulse beam are compressed using combiner rings to create a sequence of higher peak power drive-beams with gaps between. This train of drive beams is distributed from the end of the linac in the opposite direction to the main beam down a common transport line so that each drive beam can power a section of the main linac. After a 180-degree turn, each high-current, low-energy drive beam is decelerated in low-impedance decelerator structures, and the resulting power is used to accelerate the low-current, high-energy beam in the main linac. The method discussed here seems relatively inexpensive, is very flexible, and can be used to accelerate beams for linear colliders over the...

  3. High-power microwave amplifier based on overcritical relativistic electron beam without external magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Kurkin, S. A., E-mail: KurkinSA@gmail.com; Koronovskii, A. A. [Saratov State University, Astrakhanskaja 83, Saratov 410012 (Russian Federation); Saratov State Technical University, Politechnicheskaja 77, Saratov 410028 (Russian Federation); Frolov, N. S.; Hramov, A. E. [Saratov State Technical University, Politechnicheskaja 77, Saratov 410028 (Russian Federation); Saratov State University, Astrakhanskaja 83, Saratov 410012 (Russian Federation); Rak, A. O. [Belarusian State University of Informatics and Radioelectronics, Minsk (Belarus); Saratov State Technical University, Politechnicheskaja 77, Saratov 410028 (Russian Federation); Kuraev, A. A. [Belarusian State University of Informatics and Radioelectronics, Minsk (Belarus)

    2015-04-13

    The high-power scheme for the amplification of powerful microwave signals based on the overcritical electron beam with a virtual cathode (virtual cathode amplifier) has been proposed and investigated numerically. General output characteristics of the virtual cathode amplifier including the dependencies of the power gain on the input signal frequency and amplitude have been obtained and analyzed. The possibility of the geometrical working frequency tuning over the range about 8%–10% has been shown. The obtained results demonstrate that the proposed virtual cathode amplifier scheme may be considered as the perspective high-power microwave amplifier with gain up to 18 dB, and with the following important advantages: the absence of external magnetic field, the simplicity of construction, the possibility of geometrical frequency tuning, and the amplification of relatively powerful microwave signals.

  4. Transmission Power and Antenna Allocation for Energy-Efficient RF Energy Harvesting Networks with Massive MIMO

    Directory of Open Access Journals (Sweden)

    Yu Min Hwang

    2017-06-01

    Full Text Available The optimum transmission strategy for maximizing energy efficiency (EE of a multi-user massive multiple-input multiple-output (MIMO system in radio frequency energy harvesting networks is investigated. We focus on dynamic time-switching (TS antennas, to avoid the practical problems of power-splitting antennas, such as complex architectures, power loss and signal distortion when splitting the power of the received signal into power for information decoding (ID and energy harvesting (EH. However, since a single TS antenna cannot serve ID and EH simultaneously, the MIMO system is considered in this paper. We thus formulate an EE optimization problem and propose an iterative algorithm as a tractable solution, including an antenna selection strategy to optimally switch each TS antenna between ID mode and EH mode using nonlinear fractional programming and the Lagrange dual method. Further, the problem is solved under practical constraints of maximum transmission power and outage probabilities for a minimum amount of harvested power and rate capacity for each user. Simulation results show that the proposed algorithm is more energy-efficient than that of baseline schemes, and demonstrates the trade-off between the required amount of harvested power and energy efficiency.

  5. Use of a Two-Axis Joystick for Control of Externally Powered, Shoulder Disarticulation Prostheses

    Science.gov (United States)

    Lipschutz, Robert D.; Lock, Blair; Sensinger, Jonathon; Schultz, Aimee E.; Kuiken, Todd A.

    2015-01-01

    We explored a new method for simple and accurate control of shoulder movement for externally powered shoulder disarticulation prostheses using a two-axis joystick. Ten subjects with intact shoulders and arms were tested to determine the average amount of shoulder motion and force available for control of an electronic input device. This information was then applied to two different input strategies in order to examine their effectiveness: (1) a traditional strategy implemented with a rocker potentiometer and a pair of force-sensing resistors (FSRs), and (2) a strategy implemented with a two-axis joystick. Three able-bodied subjects and two subjects with shoulder disarticulation amputations attempted to control an experimental powered shoulder using both control strategies. Two powered arms were tested, one with powered flexion/extension and humeral rotation, and one with powered flexion/extension and adduction/abduction. Overwhelmingly, the subjects preferred the joystick control, as it was more intuitively linked with their shoulder movement. Additionally, two motions (one in each axis) could be controlled simultaneously. This pilot study provides valuable insight into an effective means of controlling high-level, externally powered prostheses via a two-axis joystick. PMID:21938653

  6. Spectrally narrowed external-cavity high-power stack of laser diode arrays.

    Science.gov (United States)

    Zhu, H; Ruset, I C; Hersman, F W

    2005-06-01

    We describe an effective external cavity for narrowing the spectral linewidth of a multiarray stack of laser diode arrays. For a commercially available 279-W free-running five-array laser diode array operating at 60 A, we narrow the spectral linewidth to 0.40 nm at FWHM with 115 W of cw power output. This technique leads to the possibility of higher-efficiency, lower-cost production of hyperpolarized noble gases for magnetic resonance imaging.

  7. Versatile Low Level RF System For Linear Accelerators

    Science.gov (United States)

    Potter, James M.

    2011-06-01

    The Low Level RF (LLRF) system is the source of all of the rf signals required for an rf linear accelerator. These signals are amplified to drive accelerator and buncher cavities. It can even provide the synchronizing signal for the rf power for a synchrotron. The use of Direct Digital Synthesis (DDS) techniques results in a versatile system that can provide multiple coherent signals at the same or different frequencies with adjustable amplitudes and phase relations. Pulsing the DDS allows rf switching with an essentially infinite on/off ratio. The LLRF system includes a versatile phase detector that allows phase-locking the rf frequency to a cavity at any phase angle over the full 360° range. With the use of stepper motor driven slug tuners multiple cavity resonant frequencies can be phase locked to the rf source frequency. No external phase shifters are required and there is no feedback loop phase setup required. All that is needed is to turn the frequency feedback on. The use of Digital Signal Processing (DSP) allows amplitude and phase control over the entire rf pulse. This paper describes the basic principles of a LLRF system that has been used for both proton accelerators and electron accelerators, including multiple tank accelerators, sub-harmonic and fundamental bunchers, and synchrotrons.

  8. Design of Digital Predistortion Technique for RF Power Amplifier using Memory Polynomial

    Directory of Open Access Journals (Sweden)

    Er. Sweety Badhwar

    2014-09-01

    Full Text Available Linearization of power amplifier has been an area of intense research from the last many years. The various types of linearization techniques are available for linearising PA but Digital Predistortion technique has been observed as one of the most common and effective method. But due to the issues like memory effects and exact characterization of non-linear behaviour of power amplifier, the implementation of existing predistortion technique suffers. So in this paper, a digital predistorter based on memory polynomial has been proposed that takes care of above mentioned issues. The presented technique is easy to implement and simple.

  9. Spectral Analysis of Polynomial Nonlinearity with Applications to RF Power Amplifiers

    Directory of Open Access Journals (Sweden)

    G. Tong Zhou

    2004-09-01

    Full Text Available The majority of the nonlinearity in a communication system is attributed to the power amplifier (PA present at the final stage of the transmitter chain. In this paper, we consider Gaussian distributed input signals (such as OFDM, and PAs that can be modeled by memoryless or memory polynomials. We derive closed-form expressions of the PA output power spectral density, for an arbitrary nonlinear order, based on the so-called Leonov-Shiryaev formula. We then apply these results to answer practical questions such as the contribution of AM/PM conversion to spectral regrowth and the relationship between memory effects and spectral asymmetry.

  10. Strong relationships exist between muscle volume, joint power and whole-body external mechanical power in adults and children.

    Science.gov (United States)

    O'Brien, Thomas D; Reeves, Neil D; Baltzopoulos, Vasilios; Jones, David A; Maganaris, Constantinos N

    2009-06-01

    The present study investigated whether differences between adults and children in mechanical power during single-joint knee extension tasks and the complex multijoint task of jumping could be explained by differences in the quadriceps femoris muscle volume. Peak power was calculated during squat jumps, from the integral of the vertical force measured by a force plate, and during concentric knee extensions at 30, 90, 120, 180 and 240 deg s(-1), and muscle volume was measured from magnetic resonance images for 10 men, 10 women, 10 prepubertal boys and 10 prepubertal girls. Peak power during jumping and isokinetic knee extension was significantly higher in men than in women, and in both adult groups compared with children (P power was normalized to muscle volume, the intergroup differences ceased to exist for both tasks. Peak power correlated significantly with quadriceps volume (P power that occurs with maturation in the two genders not only in kinematically constrained knee extensions but also in multijoint tasks. Future studies should examine the role of other factors relating to the generation and transmission of contractile power, such as muscle architecture, tendon stiffness and external mechanical leverage.

  11. Integral electrical characteristics and local plasma parameters of a RF ion thruster

    Energy Technology Data Exchange (ETDEWEB)

    Masherov, P. E.; Riaby, V. A., E-mail: riaby2001@yahoo.com [Research Institute of Applied Mechanics and Electrodynamics of the Moscow Aviation Institute (National Research University), Moscow (Russian Federation); Godyak, V. A. [Electrical Engineering and Computer Science Department, University of Michigan, Ann Arbor, Michigan 48109, USA and RF Plasma Consulting, Brookline, Massachusetts 02446 (United States)

    2016-02-15

    Comprehensive diagnostics has been carried out for a RF ion thruster based on inductively coupled plasma (ICP) source with an external flat antenna coil enhanced by ferrite core. The ICP was confined within a cylindrical chamber with low aspect ratio to minimize plasma loss to the chamber wall. Integral diagnostics of the ICP electrical parameters (RF power balance and coil current) allowed for evaluation of the antenna coils, matching networks, and eddy current loss and the true RF power deposited to plasma. Spatially resolved electron energy distribution functions, plasma density, electron temperatures, and plasma potentials were measured with movable Langmuir probes.

  12. Development of a Hybrid Power Supply and RF Transmission Line for SANAEM RFQ Accelerator

    CERN Document Server

    Ogur, S; Unel, G; Alacakir, A

    2015-01-01

    SANAEM Project Prometheus (SPP) has been building a proton beamline at MeV range. Its proton source, two solenoids, and a low energy diagnostic box have been already manufactured and installed. These are going to be followed by a 4-vane RFQ to be powered by two stage PSU. The first stage is a custom-built solid state amplifier providing 6 kW at 352.2 MHz operating frequency. The second stage, employing TH 595 tetrodes from Thales, will amplify this input to 160 kW in a short pulsed mode. The power transfer to the RFQ will be achieved by the means of a number of WR2300 full and half height waveguides, 3 1/8" rigid coaxial cables, joined by appropriate adapters and converters and by a custom design circulator. This paper summarizes the experience acquired during the design and the production of these components.

  13. An overview on recent developments in RF and microwave power H-terminated diamond MESFET technology

    OpenAIRE

    Ghione, Giovanni; Camarchia, Vittorio; Pirola, Marco; Cappelluti, Federica

    2014-01-01

    Thanks to its wide bandgap, exceptionally high thermal conductivity and relatively high carrier velocities, diamond exhibits attractive semiconductor properties that make it an interesting candidate for high power, high frequency and high temperature solid-state microelectronic devices, able to withstand harsh environmental conditions (in terms of temperature and/or radiation). The development of a diamond transistor technology has been restricted for many years due to the difficulty in imple...

  14. An Implantable Cardiovascular Pressure Monitoring System with On-Chip Antenna and RF Energy Harvesting

    Directory of Open Access Journals (Sweden)

    Yu-Chun Liu

    2015-08-01

    Full Text Available An implantable wireless system with on-chip antenna for cardiovascular pressure monitor is studied. The implantable device is operated in a batteryless manner, powered by an external radio frequency (RF power source. The received RF power level can be sensed and wirelessly transmitted along with blood pressure signal for feedback control of the external RF power. The integrated electronic system, consisting of a capacitance-to-voltage converter, an adaptive RF powering system, an RF transmitter and digital control circuitry, is simulated using a TSMC 0.18 μm CMOS technology. The implanted RF transmitter circuit is combined with a low power voltage-controlled oscillator resonating at 5.8 GHz and a power amplifier. For the design, the simulation model is setup using ADS and HFSS software. The dimension of the antenna is 1 × 0.6 × 4.8 mm3 with a 1 × 0.6 mm2 on-chip circuit which is small enough to place in human carotid artery.

  15. Microfluidic stretchable RF electronics.

    Science.gov (United States)

    Cheng, Shi; Wu, Zhigang

    2010-12-07

    Stretchable electronics is a revolutionary technology that will potentially create a world of radically different electronic devices and systems that open up an entirely new spectrum of possibilities. This article proposes a microfluidic based solution for stretchable radio frequency (RF) electronics, using hybrid integration of active circuits assembled on flex foils and liquid alloy passive structures embedded in elastic substrates, e.g. polydimethylsiloxane (PDMS). This concept was employed to implement a 900 MHz stretchable RF radiation sensor, consisting of a large area elastic antenna and a cluster of conventional rigid components for RF power detection. The integrated radiation sensor except the power supply was fully embedded in a thin elastomeric substrate. Good electrical performance of the standalone stretchable antenna as well as the RF power detection sub-module was verified by experiments. The sensor successfully detected the RF radiation over 5 m distance in the system demonstration. Experiments on two-dimensional (2D) stretching up to 15%, folding and twisting of the demonstrated sensor were also carried out. Despite the integrated device was severely deformed, no failure in RF radiation sensing was observed in the tests. This technique illuminates a promising route of realizing stretchable and foldable large area integrated RF electronics that are of great interest to a variety of applications like wearable computing, health monitoring, medical diagnostics, and curvilinear electronics.

  16. Compression and radiation of high-power short rf pulses. II. A novel antenna array design with combined compressor/radiator elements

    KAUST Repository

    Sirenko, Kostyantyn

    2011-01-01

    The paper discusses the radiation of compressed high power short RF pulses using two different types of antennas: (i) A simple monopole antenna and (ii) a novel array design, where each of the elements is constructed by combining a compressor and a radiator. The studies on the monopole antenna demonstrate the possibility of a high power short RF pulse\\'s efficient radiation even using simple antennas. The studies on the novel array design demonstrate that a reduced size array with lower pulse distortion and power decay can be constructed by assembling the array from elements each of which integrates a compressor and a radiator. This design idea can be used with any type of antenna array; in this work it is applied to a phased array.

  17. CMOS工艺射频功率放大器的实现与验证%Realization and verification of the CMOS technology RF power amplifier

    Institute of Scientific and Technical Information of China (English)

    谢君

    2011-01-01

    RF power amplifiers are key components in wireless devices, CaAs technology is widely used in the design and manufacture of RF power amplifier. But the CMOS technology has the very big superiority in the production maturity and the cost, this paper focuses on the problems that using CMOS technology to do the RF power amplifier, introduces the world's first mass product CMOS power amplifier and the special techniques used. Using a mature handset product, it replaces this power amplifier and the peripheral components, and finally carries on the contrast test with the original product.%射频功率放大器是无线设备的关键器件,GaAs工艺被广泛使用在射频功放的设计制造上.而CMOS工艺在生产成熟度和成本上有很大优势,主要关注用CMOS工艺来做射频功放的问题,介绍世界上第一颗量产的CMOS功放及其所使用的特殊技术.利用一款成熟的手机产品,替换这颗功放及外围器件,最后与原产品进行对比测试.

  18. A high dynamic range linear RF power detector with a preceding LNA

    Science.gov (United States)

    Yingbo, Dai; Kefeng, Han; Na, Yan; Xi, Tan

    2012-01-01

    A design of high dynamic range linear radio frequency power detector (PD), aimed for transmitter carrier leakage suppression is presented in this paper. Based on the logarithmic amplifier principle, this detector utilizes the successive detection method to achieve a high dynamic range in the radio frequency band. In order to increase sensitivity, a low noise amplifier (LNA) is placed in the front of this detector. DC coupling is adopted in this architecture to reduce parasitics and save area, but this will unavoidably cause DC offsets in the circuit which are detrimental to the dynamic range. So a DC offset cancelling (DCOC) technique is proposed to solve the problem. Finally, this detector was fabricated in the SMIC 0.13 μm CMOS process. The measured results show that it achieves a wide dynamic range of 50 dB/40 dB with log errors in ±1 dB at 900 MHz/2 GHz, while draws 16 mA from a 1.5 V power supply. The active chip area is 0.27 × 0.67 mm2.

  19. Studies of High Power RF-induced Turbulence in the Ionosphere over HAARP

    Science.gov (United States)

    Sheerin, J. P.; Watkins, B. J.; Bristow, W. A.; Bernhardt, P. A.

    2016-12-01

    The HAARP phased-array HF transmitter at Gakona, AK delivers up to 3.6 GW (ERP) of HF power in the range of 2.8 - 10 MHz to the ionosphere with millisecond pointing, power modulation, and frequency agility. HAARP's unique features have enabled the conduct of a number of nonlinear plasma experiments in the interaction region of overdense ionospheric plasma including stimulated electromagnetic emissions (SEE), artificial aurora, artificial ionization layers, VLF wave-particle interactions in the magnetosphere, strong Langmuir turbulence (SLT) and suprathermal electron acceleration. Diagnostics include the Modular UHF Ionospheric Radar (MUIR) sited at HAARP, the SuperDARN-Kodiak HF radar, spacecraft radio beacons, HF receivers to record stimulated electromagnetic emissions (SEE) and telescopes and cameras for optical emissions. We report on short timescale ponderomotive overshoot effects, artificial field-aligned irregularities (AFAI), the aspect angle dependence of the intensity of the plasma line, and production of suprathermal electrons. For a narrow range of HF pointing between Spitze and magnetic zenith, a reduced threshold for AFAI is observed. Recent results of simulations of these experiments enable interpretation of many observed features. Applications are made to the study of irregularities relevant to spacecraft communication and navigation systems.

  20. Environmental externalities: Applying the concept to Asian coal-based power generation

    Energy Technology Data Exchange (ETDEWEB)

    Szpunar, C.B.; Gillette, J.L.

    1993-03-01

    This report examines the concept of environmental externality. It discusses various factors -- the atmospheric transformations, relationship of point-source emissions to ambient air quality, dose-response relationships, applicable cause-and-effect principles, and risk and valuation research -- that are considered by a number of state utilities when they apply the environmental externality concept to energy resource planning. It describes a methodology developed by Argonne National Laboratory for general use in resource planning, in combination with traditional methods that consider the cost of electricity production. Finally, it shows how the methodology can be applied in Indonesia, Thailand, and Taiwan to potential coal-fired power plant projects that will make use of clean coal technologies.

  1. A comparison of lower and higher LET heavy ion irradiation effects on silicon NPN rf power transistors

    Science.gov (United States)

    Bharathi, M. N.; Pushpa, N.; Vinayakprasanna, N. H.; Prakash, A. P. Gnana

    2016-06-01

    The Silicon NPN rf power transistors were irradiated with 180 MeV Au14+ and 150 MeV Ag12+ ions in the dose range of 1 Mrad to 100 Mrad. The SRIM simulation was used to understand the energy loss and range of these ions in the transistor structure. The different electrical parameters such as Gummel characteristics, excess base current (∆IB), dc current gain (hFE), transconductance (gm), displacement damage factor (K) and output characteristics were studied systematically before and after irradiation. These results were compared with lower linear energy transfer (LET) ions such as 50 MeV Li3+, 95 MeV O7+, 100 MeV F8+, 140 MeV Si10+ and 175 MeV Ni13+ ions in the same dose range. The degradation for 180 MeV Au14+ and 150 MeV Ag12+ ion irradiated transistors was significantly more when compared to lower LET ions, indicating that the transistors are vulnerable to higher LET ion irradiations. Isochronal annealing study was conducted on the irradiated transistors to analyze the recovery in different electrical parameters. After isochronal annealing, the recovery in hFE and other electrical parameters was around 67% for Ag12+ ion irradiated transistors and 60% for Au14+ ion irradiated transistors.

  2. RF dosimetry: a comparison between power absorption of female and male numerical models from 0.1 to 4 GHz

    Energy Technology Data Exchange (ETDEWEB)

    Sandrini, L; Vaccari, A; Malacarne, C; Cristoforetti, L; Pontalti, R [ITC-irst-Bioelectromagnetism Lab., FCS Department, 38050 Povo (Trento) (Italy)

    2004-11-21

    Realistic numerical models of human subjects and their surrounding environment represent the basic points of radiofrequency (RF) electromagnetic dosimetry. This also involves differentiating the human models in men and women, possibly with different body shapes and postures. In this context, the aims of this paper are, firstly, to propose a female dielectric anatomical model (fDAM) and, secondly, to compare the power absorption distributions of a male and a female model from 0.1 to 4 GHz. For realizing the fDAM, a magnetic resonance imaging tomographer to acquire images and a recent technique which avoids the discrete segmentation of body tissues into different types have been used. Simulations have been performed with the FDTD method by using a novel filtering-based subgridding algorithm. The latter is applied here for the first time to dosimetry, allowing an abrupt mesh refinement by a factor of up to 7. The results show that the whole-body-averaged specific absorption rate (WBA-SAR) of the female model is higher than that of the male counterpart, mainly because of a thicker subcutaneous fat layer. In contrast, the maximum averaged SAR over 1 g (1gA-SAR) and 10 g (10gA-SAR) does not depend on gender, because it occurs in regions where no subcutaneous fat layer is present.

  3. Power density, field intensity, and carrier frequency determinants of RF-energy-induced calcium-ion efflux from brain tissue

    Energy Technology Data Exchange (ETDEWEB)

    Joines, W.T.; Blackman, C.F.

    1980-01-01

    To explain a carrier frequency dependence reported for radiofrequency (RF)-induced calcium-ion efflux from brain tissue, a chick-brain hemisphere bathed in buffer solution is modeled as a sphere within the uniform field of the incident electromagnetic wave. Calculations on a spherical model show that the average electric-field intensity within the sample remains the same at different carrier frequencies if the incident power density (Pi) is adjusted by an amount that compensates for the change in complex permittivity (epsilon *r) and the change of wavelength, as a function of carrier frequency. The resulting formula for transforming Pi is seen to follow the pattern of both positive and negative demonstrations of calcium-ion efflux that have been observed at carrier frequencies of 50, 147, and 450 MHz. Indeed, all results obtained at these three frequencies, when related by Pi's that produce the same average electric-field intensity within the sample, are seen to be in agreement; no prediction is contradicted by an experiment.

  4. Feasibility study of monitoring of plasma etching chamber conditions using superimposed high-frequency signals on rf power transmission line.

    Science.gov (United States)

    Kasashima, Y; Uesugi, F

    2015-10-01

    An in situ monitoring system that can detect changes in the conditions of a plasma etching chamber has been developed. In the system, low-intensity high-frequency signals are superimposed on the rf power transmission line used for generating plasma. The system measures reflected high-frequency signals and detects the change in their frequency characteristics. The results indicate that the system detects the changes in the conditions in etching chambers caused by the changes in the electrode gap and the inner wall condition and demonstrate the effectiveness of the system. The system can easily be retrofitted to mass-production equipment and it can be used with or without plasma discharge. Therefore, our system is suitable for in situ monitoring of mass-production plasma etching chambers. The system is expected to contribute to development of predictive maintenance, which monitors films deposited on the inner wall of the chamber and prevents equipment faults caused by misalignment of chamber parts in mass-production equipment.

  5. Acute effect of static stretching on power output during concentric dynamic constant external resistance leg extension.

    Science.gov (United States)

    Yamaguchi, Taichi; Ishii, Kojiro; Yamanaka, Masanori; Yasuda, Kazunori

    2006-11-01

    The purpose of the present study was to clarify the effect of static stretching on muscular performance during concentric isotonic (dynamic constant external resistance [DCER]) muscle actions under various loads. Concentric DCER leg extension power outputs were assessed in 12 healthy male subjects after 2 types of pretreatment. The pretreatments included (a) static stretching treatment performing 6 types of static stretching on leg extensors (4 sets of 30 seconds each with 20-second rest periods; total duration 20 minutes) and (b) nonstretching treatment by resting for 20 minutes in a sitting position. Loads during assessment of the power output were set to 5, 30, and 60% of the maximum voluntary contractile (MVC) torque with isometric leg extension in each subject. The peak power output following the static stretching treatment was significantly (p extensive static stretching significantly reduces power output with concentric DCER muscle actions under various loads. Common power activities are carried out by DCER muscle actions under various loads. Therefore, the result of the present study suggests that relatively extensive static stretching decreases power performance.

  6. A power-efficient communication system between brain-implantable devices and external computers.

    Science.gov (United States)

    Yao, Ning; Lee, Heung-No; Chang, Cheng-Chun; Sclabassi, Robert J; Sun, Mingui

    2007-01-01

    In this paper, we propose a power efficient communication system for linking a brain-implantable device to an external system. For battery powered implantable devices, the processor and the transmitter power should be reduced in order to both conserve battery power and reduce the health risks associated with transmission. To accomplish this, a joint source-channel coding/decoding system is devised. Low-density generator matrix (LDGM) codes are used in our system due to their low encoding complexity. The power cost for signal processing within the implantable device is greatly reduced by avoiding explicit source encoding. Raw data which is highly correlated is transmitted. At the receiver, a Markov chain source correlation model is utilized to approximate and capture the correlation of raw data. A turbo iterative receiver algorithm is designed which connects the Markov chain source model to the LDGM decoder in a turbo-iterative way. Simulation results show that the proposed system can save up to 1 to 2.5 dB on transmission power.

  7. ADX: A high Power Density, Advanced RF-Driven Divertor Test Tokamak for PMI studies

    Science.gov (United States)

    Whyte, Dennis; ADX Team

    2015-11-01

    The MIT PSFC and collaborators are proposing an advanced divertor experiment, ADX; a divertor test tokamak dedicated to address critical gaps in plasma-material interactions (PMI) science, and the world fusion research program, on the pathway to FNSF/DEMO. Basic ADX design features are motivated and discussed. In order to assess the widest range of advanced divertor concepts, a large fraction (>50%) of the toroidal field volume is purpose-built with innovative magnetic topology control and flexibility for assessing different surfaces, including liquids. ADX features high B-field (>6 Tesla) and high global power density (P/S ~ 1.5 MW/m2) in order to access the full range of parallel heat flux and divertor plasma pressures foreseen for reactors, while simultaneously assessing the effect of highly dissipative divertors on core plasma/pedestal. Various options for efficiently achieving high field are being assessed including the use of Alcator technology (cryogenic cooled copper) and high-temperature superconductors. The experimental platform would also explore advanced lower hybrid current drive and ion-cyclotron range of frequency actuators located at the high-field side; a location which is predicted to greatly reduce the PMI effects on the launcher while minimally perturbing the core plasma. The synergistic effects of high-field launchers with high total B on current and flow drive can thus be studied in reactor-relevant boundary plasmas.

  8. RF BREAKDOWN STUDIES USING PRESSURIZED CAVITIES

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Rolland

    2014-09-21

    1.3 GHz RF test cell capable of operating both at high pressure and in vacuum with replaceable electrodes was designed, built, and power tested in preparation for testing the frequency and geometry effects of RF breakdown at Argonne National Lab. At the time of this report this cavity is still waiting for the 1.3 GHz klystron to be available at the Wakefield Test Facility. (3) Under a contract with Los Alamos National Lab, an 805 MHz RF test cavity, known as the All-Seasons Cavity (ASC), was designed and built by Muons, Inc. to operate either at high pressure or under vacuum. The LANL project to use the (ASC) was cancelled and the testing of the cavity has been continued under the grant reported on here using the Fermilab Mucool Test Area (MTA). The ASC is a true pillbox cavity that has performed under vacuum in high external magnetic field better than any other and has demonstrated that the high required accelerating gradients for many muon cooling beam line designs are possible. (4) Under ongoing support from the Muon Acceleration Program, microscopic surface analysis and computer simulations have been used to develop models of RF breakdown that apply to both pressurized and vacuum cavities. The understanding of RF breakdown will lead to better designs of RF cavities for many applications. An increase in the operating accelerating gradient, improved reliability and shorter conditioning times can generate very significant cost savings in many accelerator projects.

  9. Dependence of beam emittance on plasma electrode temperature and rf-power, and filter-field tuning with center-gapped rod-filter magnets in J-PARC rf-driven H{sup −} ion source

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, A., E-mail: akira.ueno@j-parc.jp; Koizumi, I.; Ohkoshi, K.; Ikegami, K.; Takagi, A.; Yamazaki, S.; Oguri, H. [J-PARC Center, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195 (Japan)

    2014-02-15

    The prototype rf-driven H{sup −} ion-source with a nickel plated oxygen-free-copper (OFC) plasma chamber, which satisfies the Japan Proton Accelerator Research Complex (J-PARC) 2nd stage requirements of a H{sup −} ion beam current of 60 mA within normalized emittances of 1.5 π mm mrad both horizontally and vertically, a flat top beam duty factor of 1.25% (500 μs × 25 Hz) and a life-time of more than 50 days, was reported at the 3rd international symposium on negative ions, beams, and sources (NIBS2012). The experimental results of the J-PARC ion source with a plasma chamber made of stainless-steel, instead of nickel plated OFC used in the prototype source, are presented in this paper. By comparing these two sources, the following two important results were acquired. One was that the about 20% lower emittance was produced by the rather low plasma electrode (PE) temperature (T{sub PE}) of about 120 °C compared with the typically used T{sub PE} of about 200 °C to maximize the beam current for the plasma with the abundant cesium (Cs). The other was that by using the rod-filter magnets with a gap at each center and tuning the gap-lengths, the filter-field was optimized and the rf-power necessary to produce the J-PARC required H{sup −} ion beam current was reduced typically 18%. The lower rf-power also decreases the emittances.

  10. Proposal to negotiate two blanket purchase contracts, without competitive tendering, for the supply of high-power RF grid-tubes for the CERN accelerators

    CERN Document Server

    2005-01-01

    This document concerns the award of two contracts, without competitive tendering, for the supply of different types of RF high-power grid-tubes (triodes and tetrodes) for the operation of CERN accelerators. For the reasons set out in this document, the Finance Committee is invited to agree to the negotiation of two blanket purchase contracts, without competitive tendering, for the supply of different types of RF high-power grid-tubes (triodes and tetrodes) with: - THALES (FR) for a total amount of 6 800 000 euros (10 540 000 Swiss francs) for a period of five years, subject to revision for inflation from January 2006; - RICHARDSON (DE) for a total amount of 1 100 000 euros (1 705 000 Swiss francs) for a period of five years, subject to revision for inflation from January 2006.

  11. Design, Fabrication and High Power RF Test of a C-band Accelerating Structure for Feasibility Study of the SPARC photo-injector energy upgrade

    CERN Document Server

    Alesini, D.; Di Pirro, G.; Di Raddo, R.; Ferrario, M.; Gallo, A.; Lollo, V.; Marcellini, F.; Higo, T.; Kakihara, K.; Matsumoto, S.; Campogiani, G.; Mostacci, A.; Palumbo, L.; Persichelli, S.; Spizzo, V.; Verdú-Andrés, S.

    2011-01-01

    The energy upgrade of the SPARC photo-injector from 160 to more than 260 MeV will be done by replacing a low gradient 3m S-Band structure with two 1.4m high gradient C-band structures. The structures are travelling wave, constant impedance sections, have symmetric waveguide input couplers and have been optimized to work with a SLED RF input pulse. A prototype with a reduced number of cells has been fabricated and tested at high power in KEK (Japan) giving very good performances in terms of breakdown rates (10^6 bpp/m) at high accelerating gradient (>50 MV/m). The paper illustrates the design criteria of the structures, the fabrication procedure and the high power RF test results.

  12. 1.38 W tunable high-power narrow-linewidth external-cavity tapered amplifier at 670 nm

    DEFF Research Database (Denmark)

    Chi, Mingjun; Erbert, G.; Sumpf, B.;

    2010-01-01

    A diffraction-limited narrow-linewidth diode laser system based on a tapered amplifier in external cavity is demonstrated. 1.38 W output power is obtained. The laser system is tunable from 659 to 675 nm.......A diffraction-limited narrow-linewidth diode laser system based on a tapered amplifier in external cavity is demonstrated. 1.38 W output power is obtained. The laser system is tunable from 659 to 675 nm....

  13. Computations of longitudinal electron dynamics in the recirculating cw RF accelerator-recuperator for the high average power FEL

    Science.gov (United States)

    Sokolov, A. S.; Vinokurov, N. A.

    1994-03-01

    The use of optimal longitudinal phase-energy motion conditions for bunched electrons in a recirculating RF accelerator gives the possibility to increase the final electron peak current and, correspondingly, the FEL gain. The computer code RECFEL, developed for simulations of the longitudinal compression of electron bunches with high average current, essentially loading the cw RF cavities of the recirculator-recuperator, is briefly described and illustrated by some computational results.

  14. A novel high efficiency CMOS RF/DC power harvester based on constant on/off time buck controller for 60GHz frequency band

    Directory of Open Access Journals (Sweden)

    Ninić Marko

    2017-01-01

    Full Text Available A novel 60 GHz RF/DC power harvesting system is presented. The system consists of RF to DC rectifier and a DC/DC Buck converter based on constant ON/OFF time (COOT control. The rectifier has a structure of voltage doubler, but employs diodes that have lower parasitics compared to those of the standard MOSFET diodes, resulting in improved power conversion efficiency. The peak efficiency of the rectifier obtained with the extracted parasitics for the output power of 1 mW is about 25%. In order to keep the output voltage of the system to 1.2 V, the COOT control in the Buck converter is used. COOT control has much better efficiency at low output powers compared to the PWM systems. For correct operation of the COOT control, auxiliary sub-blocks: a low power high-speed comparator, a hysteresis comparator, and a high-speed voltage reference are designed and presented. The maximum switching frequency in the Buck converter is about 100MHz and the whole control system has very low static power consumption. The efficiency of the overall system for the output power of 1mW is about 21%. The system is designed in 65 nm CMOS technology.

  15. Multiplying probe for accurate power measurements on an RF driven atmospheric pressure plasma jet applied to the COST reference microplasma jet

    Science.gov (United States)

    Beijer, P. A. C.; Sobota, A.; van Veldhuizen, E. M.; Kroesen, G. M. W.

    2016-03-01

    In this paper a new multiplying probe for measuring the power dissipated in a miniature capacitively coupled, RF driven, atmospheric pressure plasma jet (μAPPJ—COST Reference Microplasma Jet—COST RMJ) is presented. The approach aims for substantially higher accuracy than provided by traditionally applied methods using bi-directional power meters or commercially available voltage and current probes in conjunction with digitizing oscilloscopes. The probe is placed on a miniature PCB and designed to minimize losses, influence of unknown elements, crosstalk and variations in temperature. The probe is designed to measure powers of the order of magnitude of 0.1-10 W. It is estimated that it measures power with less than 2% deviation from the real value in the tested power range. The design was applied to measure power dissipated in COST-RMJ running in helium with a small addition of oxygen.

  16. Minimization of the external heating power by long fusion power rise-up time for self-ignition access in the helical reactor FFHR2m

    Science.gov (United States)

    Mitarai, O.; Sagara, A.; Chikaraishi, H.; Imagawa, S.; Watanabe, K.; Shishkin, A. A.; Motojima, O.

    2007-11-01

    Minimization of the external heating power to access self-ignition is advantageous to increase the reactor design flexibility and to reduce the capital and operating costs of the plasma heating device in a helical reactor. In this work we have discovered that a larger density limit leads to a smaller value of the required confinement enhancement factor, a lower density limit margin reduces the external heating power and over 300 s of the fusion power rise-up time makes it possible to reach a minimized heating power. While the fusion power rise-up time in a tokamak is limited by the OH transformer flux or the current drive capability, any fusion power rise-up time can be employed in a helical reactor for reducing the thermal stresses of the blanket and shields, because the confinement field is generated by the external helical coils.

  17. Effect of RF power and gas flow ratio on the growth and morphology of the PECVD SiC thin films for MEMS applications

    Indian Academy of Sciences (India)

    Bhavana Peri; Bikash Borah; Raj Kishora Dash

    2015-08-01

    Low-temperature plasma enhanced chemical vapour deposition (PECVD) deposited silicon carbide (SiC) thin films are promising materials for the development of high-temperature working microelectromechanical system (MEMS) owing to their excellent mechanical properties, non-corrosive nature and ability to withstand high temperature. However, the surface roughness of such thin films is the main obstacle to achieve thicker thin films for MEMS applications as the surface becomes more rougher with the increase in the thickness of PECVD SiC thin films. Therefore, in this present study, thicker SiC thin films were deposited by PECVD process by using CH4 and SiH4 as the precursor gases in the presence of Ar as the carrier gas and two process parameters, i.e., radio frequency (RF) power with mixed frequency condition and flow ratio of silane to methane were varied by keeping the temperature and pressure constant to investigate the influence of these parameters on the growth rate, surface roughness and morphology of SiC thin films. It was observed that both the RF power (with the mixed frequency condition) and flow ratio of SiH4/CH4 can control the growth rate, surface roughness and morphology of the PECVD SiC thin films. Higher the carbon content in the thin films the surface became more smoother, whereas the surface became for rougher by increasing the RF power.

  18. Spatial and RF power dependence of the structural and electrical characteristics of copper zinc tin selenide thin films prepared by single elementary target sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Yeon Hwa; Jang, Jin Woo; Cho, Yong Soo, E-mail: ycho@yonsei.ac.kr

    2014-11-14

    The spatial variations of the structural, optical and electrical properties of Cu{sub 2}ZnSnSe{sub 4} thin films grown by radio-frequency (RF) magnetron sputtering across a distance of 60 mm were investigated as a function of the discharge power. Noticeable changes in the deposition rate and elemental distribution were observed in the as-deposited films at the central and near-edge regions. After annealing in a Se atmosphere, the dependence of the phase evolution and electrical properties on the spatial position and power was also evident. Deposition at a low power of 30 W seems to be more promising in generating dominant Cu{sub 2}ZnSnSe{sub 4} phase with well-packed crystallites on the surface. On the other hand, deposition at higher power tended to result in a significant portion of a secondary SnSe{sub 2} phase, which is responsible for the higher optical band gap and lower electrical resistivity, depending on the specific region of the film. - Highlights: • Single elementary target sputtering of Cu{sub 2}ZnSnSe{sub 4} thin films for solar cells. • Deposition rate and elemental distribution are different at central and edge regions. • Low RF power is promising in generating single phase with less spatial variation. • High RF power induces a secondary SnSe{sub 2} phase and a higher band gap. • Carrier concentration is smaller at centers than at near-edges of the films.

  19. Human health-related externalities in energy system modelling the case of the Danish heat and power sector

    DEFF Research Database (Denmark)

    Zvingilaite, Erika

    2011-01-01

    This paper discusses methodology of energy system modelling when reduction of local externalities, such as damage to the human health from energy production-related air pollution, is in focus. Ideally, the local energy externalities should be analysed by adopting the impact pathway approach...... of ExternE study, and following the pollutants from their release to the personal uptake and resulting health effects. This would require inclusion of air pollution modelling and monetary valuation of the impacts into an energy system optimisation process. However, this approach involves a complex study...... and power sector verifies that it is cheaper for the society to include externalities in the planning of an energy system than to pay for the resulting damages later. Total health costs decrease by around 18% and total system costs decrease by nearly 4% when health externalities are included...

  20. Microstructure and characterization of Al-doped ZnO films prepared by RF power sputtering on Al and ZnO targets

    Energy Technology Data Exchange (ETDEWEB)

    Tseng, Chun-An [Department of Mechanical Engineering, National Central University, Taiwan (China); Lin, Jing-Chie, E-mail: jclincom@cc.ncu.edu.tw [Department of Mechanical Engineering, National Central University, Taiwan (China); Institute of Material Science and Engineering, National Central University, Taiwan (China); Chang, Yu-Fong [Department of Mechanical Engineering, National Central University, Taiwan (China); Chyou, San-Der [Power Research Institute, Taiwan Power Company, Taiwan (China); Peng, Kun-Cheng [Department of Materials Science and Engineering, Mingchi University of Technology, Taiwan (China)

    2012-06-01

    Al-doped zinc oxide (AZO) transparent conductive films were prepared on a glass substrate using a magnetron sputtering system with a pure zinc oxide (ZnO) target and a pure Al target sputtered using radio frequency (RF) power. The RF power was set at 100 W for the ZnO target and varied from 20 to 150 W for the Al target. The morphology of the thin films was examined by field-emission scanning electron microscope (FE-SEM), and their composition was analyzed by the equipped energy-dispersive X-ray spectroscopy (EDS). The cross section of the films determined through FE-SEM indicated that their thickness was around 650 nm. EDS analysis revealed that the Al-dopant concentration of the AZO films increased in the following order: 0.85 at.% (20 W) < 1.60 at.% (40 W) < 3.52 at.% (100 W) < 4.34 at.% (150 W). Analysis of the films using X-ray diffractometer (XRD) indicated that all films had a wurtzite structure with a texture of (0 0 2). High-resolution transmission electron microscopy (HRTEM) revealed a number of defects in the films, such as stacking faults and dislocations. Ultraviolet photoelectron spectroscopy (UPS) was used to estimate the optical energy gap (E{sub g}) for the AZO thin films. The energy gap increases from 3.39 to 3.58 eV as the RF power applied to the Al target increase. The electrical resistivity of the films decreased from 3.43 Multiplication-Sign 10{sup -2} {Omega} cm to 3.29 Multiplication-Sign 10{sup -3} {Omega} cm as the RF power increased from 20 to 150 W when a four-point probe was used to investigate. Atomic force microscope (AFM) revealed that the surface roughness of the films increased with increasing RF power. The average optical transmittance of the films was determined by UV-visible spectrometer. The films are suitable for use as transparent conductive oxide films in the optoelectronic industry. A decrease in the electrical resistivity of the film with increasing Al-dopant concentration was ascribed to an increase in the carrier

  1. High Power Experiment of X-Band Thermionic Cathode RF Gun for Compton Scattering X-ray Source

    Science.gov (United States)

    Sakamoto, Fumito; Uesaka, Mitsuru; Dobashi, Katsuhiro; Yamamoto, Tomohiko; Meng, De; Urakawa, Junji; Higo, Toshiyasu; Akemoto, Mitsuo; Matsuo, Kenichi; Sakae, Hisaharu; Yamamoto, Masashi

    2006-11-01

    We are currently developing a compact monochromatic X-ray source based on laser-electron collision. To realize remarkably compact-, high-intensity- and highly-stable-system, we adopt an X-band multi-bunch liner accelerator (linac) and reliable Q-switch laser. The X-ray yields by the multi-bunch electron beam and Q-switch Nd: YAG laser of 1.4 J/10 ns (FWHM) (532 nm, second harmonic) is 107 photons/RF-pulse (108 photons/sec for 10 Hz operation). The injector of the system consists of a 3.5-cell X-band thermionic cathode RF gun and an alpha magnet. So far we have achieved beam generation from the X-band thermionic cathode RF gun. The peak beam energy is 2 MeV. This experimental high energy (˜2 MeV) beam generation from the X-band thermionic cathode RF gun is the first in the world. In this paper, we describe the system of the Compton scattering X-ray source based on the X-band linac, experimental results of X-band thermionic cathode RF gun and the details of the experimental setup for Compton scattering X-ray generation that are under construction.

  2. Multi-MW 22.8 GHz Harmonic Multiplier - RF Power Source for High-Gradient Accelerator R&D

    Energy Technology Data Exchange (ETDEWEB)

    Jay L. Hirshfield

    2012-07-26

    Electrodynamic and particle simulation studies have been carried out to optimize design of a two-cavity harmonic frequency multiplier, in which a linear electron beam is energized by rotating fields near cyclotron resonance in a TE111 cavity in a uniform magnetic field, and in which the beam then radiates coherently at the nth harmonic into a TEn11 output cavity. Examples are worked out in detail for 7th and 2nd harmonic converters, showing RF-to-RF conversion efficiencies of 45% and 88%, respectively at 19.992 GHz (K-band) and 5.712 GHz (C-band), for a drive frequency of 2.856 GHz. Details are shown of RF infrastructure (S-band klystron, modulator) and harmonic converter components (drive cavity, output cavities, electron beam source and modulator, beam collector) for the two harmonic converters to be tested. Details are also given for the two-frequency (S- and C-band) coherent multi-MW test stand for RF breakdown and RF gun studies.

  3. High power external cavity laser diode arrays for the generation of hyperpolarized noble gases

    Science.gov (United States)

    Blasche, Gregory Paul

    Hyperpolarized noble gas magnetic resonance imaging promises to be a useful medical diagnostic tool due to its ability to image airways and brain function. A current limitation to widespread use is the time needed to generate gas quantities large enough for clinical patient imaging. Here I investigate line-narrowing of laser diode arrays in order to optimize the generation of hyperpolarized noble gases. Hyperpolarized noble gases are nuclear spin-½ isotopes that are polarized externally to have a large excess population of metastable spin up nuclei. When inhaled and imaged, they provide a novel tool for scientific studies and medical diagnosis in the human body. The gases are generated through a spin-exchange process via the spin-conserving hyperfine interaction of noble gas nuclei and optically pumped alkali metals. The net amount of polarized gas is limited by the optical power which is absorbed by the alkali metals as this is the first stage in the spin-exchange process. Laser diode arrays are typically used because they have a high available power for relatively low cost. Unfortunately, they are optically inefficient due to the factor of twenty larger inherent linewidth relative to the pressure broadened absorption linewidth of the alkali metal. In order to increase the efficiency of the system, I have designed and built an external cavity around the laser diode array consisting of a diffraction grating which acts as a wavelength dependent mirror tuned to the alkali metal rubidium absorption frequency. This causes the laser to operate solely at the desired wavelength, reducing the linewidth. External cavities have long been used for single element laser diodes. I extend this technique to laser diode arrays by imaging the diodes onto the grating using a set of imaging lenses forming individual cavities. I discuss the limitations on the power and linewidth achievable due to the optics of the cavity, as well as limitations caused by non-uniform heating effects

  4. Maintenance of power plants by external personnel theory and practice; Fremdfirmeneinsatz in der Instandhaltung von Kraftwerken in Theorie und Praxis

    Energy Technology Data Exchange (ETDEWEB)

    Wolff, U.; Rodemerk, F. [Stadtwerke Duesseldorf AG, Duesseldorf (Germany)

    2008-07-01

    In the liberalised market the potential in cost reduction by outsourcing of maintenance work is increasingly used in power stations. As a support to obtain the most effective and cheapest method to employ external companies in power station maintenance a team for the VGB Committee 'Maintenance Management' has compiled the instruction sheet 'Recommendations for the Outsourcing of Maintenance Services'. These recommendations, written from maintenance people for maintenance people, contain suggestions from a practical and a legal point of view and enlighten the management of external companies in the maintenance of power stations in theory and practice. (orig.)

  5. Design and investigation of bladder power pump driven by an external electromagnet

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiao; Zhou, Dongcai; Liu, Chunbao [University of Technology, Guangzhou (China); Guan, Ting [Guangzhou General Hospital of Guangzhou Military Command, Guangzhou (China)

    2014-09-15

    This study aims to evaluate the feasibility of the bladder power pump driven by an external electromagnet proposed by the authors. The structure of the pump was designed based on its working principle. The mathematical model and 3D finite element model of the electromagnetic field of the pump were established. The electromagnetic driving property of the pump was analyzed using the models, and the micturition performance of the pump was investigated in the simulated experimental system. Results show that maximum intravesical pressure and maximum urine flow rate reached 10.8 KPa and 13.9 cm{sup 3} /s, respectively, approaching the normal human urodynamic parameters. This novel pump has the potential of being used for assisting neurogenic bladder micturition.

  6. rf improvements for Spallation Neutron Source H-ion source

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Yoon W [ORNL; Fuja, Raymond E [ORNL; Goulding, Richard Howell [ORNL; Hardek, Thomas W [ORNL; Lee, Sung-Woo [ORNL; McCarthy, Mike [ORNL; Piller, Chip [ORNL; Shin, Ki [ORNL; Stockli, Martin P [ORNL; Welton, Robert F [ORNL

    2010-01-01

    The Spallation Neutron Source at Oak Ridge National Laboratory is ramping up the accelerated proton beam power to 1.4 MW and just reached 1 MW. The rf-driven multicusp ion source that originates from the Lawrence Berkeley National Laboratory has been delivering 38 mA H beam in the linac at 60 Hz, 0.9 ms. To improve availability, a rf-driven external antenna multicusp ion source with a water-cooled ceramic aluminum nitride AlN plasma chamber is developed. Computer modeling and simulations have been made to analyze and optimize the rf performance of the new ion source. Operational statistics and test runs with up to 56 mA medium energy beam transport beam current identify the 2 MHz rf system as a limiting factor in the system availability and beam production. Plasma ignition system is under development by using a separate 13 MHz system. To improve the availability of the rf power system with easier maintenance, we tested a 70 kV isolation transformer for the 80 kW, 6% duty cycle 2 MHz amplifier to power the ion source from a grounded solid-state amplifier. 2010 American Institute of Physics.

  7. A comparison of lower and higher LET heavy ion irradiation effects on silicon NPN rf power transistors

    Energy Technology Data Exchange (ETDEWEB)

    Bharathi, M.N. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570006 (India); Pushpa, N. [Department of PG Studies in Physics, JSS College, Ooty Road, Mysore 570025 (India); Vinayakprasanna, N.H. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570006 (India); Prakash, A.P. Gnana, E-mail: gnanaprakash@physics.uni-mysore.ac.in [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570006 (India)

    2016-06-21

    The Silicon NPN rf power transistors were irradiated with 180 MeV Au{sup 14+} and 150 MeV Ag{sup 12+} ions in the dose range of 1 Mrad to 100 Mrad. The SRIM simulation was used to understand the energy loss and range of these ions in the transistor structure. The different electrical parameters such as Gummel characteristics, excess base current (∆I{sub B}), dc current gain (h{sub FE}), transconductance (g{sub m}), displacement damage factor (K) and output characteristics were studied systematically before and after irradiation. These results were compared with lower linear energy transfer (LET) ions such as 50 MeV Li{sup 3+}, 95 MeV O{sup 7+}, 100 MeV F{sup 8+}, 140 MeV Si{sup 10+} and 175 MeV Ni{sup 13+} ions in the same dose range. The degradation for 180 MeV Au{sup 14+} and 150 MeV Ag{sup 12+} ion irradiated transistors was significantly more when compared to lower LET ions, indicating that the transistors are vulnerable to higher LET ion irradiations. Isochronal annealing study was conducted on the irradiated transistors to analyze the recovery in different electrical parameters. After isochronal annealing, the recovery in h{sub FE} and other electrical parameters was around 67% for Ag{sup 12+} ion irradiated transistors and 60% for Au{sup 14+} ion irradiated transistors. - Highlights: • The effects of 80 MeV Au{sup 14+} and 150 MeV Ag{sup 12+} ions on Si NPN transistors are studied. • Lower LET Results are compared with lower LET ion irradiation results. • Ionization and displacement damages of ions in transistors are simulated using SRIM. • Higher LET ions degrade dc characteristics more when compared to lower LET ions. • Isochronal annealing study was conducted on the irradiated transistors. • After annealing, the recovery in h{sub FE} and other electrical parameters are significant.

  8. 805 MHz and 201 MHz RF cavity development for MUCOOL

    Energy Technology Data Exchange (ETDEWEB)

    Li, Derun [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Corlett, J [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Ladran, A [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); MacGill, R [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Wallig, J [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Zisman, M [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Moretti, A [Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Rowe, A [Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Qian, Z B [Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Wu, V [Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Rimmer, R A [Jefferson Lab, Newport News, VA 23606 (United States); Norem, J [Argonne National Laboratory, Argonne, IL 60439 (United States); Summers, D [University of Mississippi at Oxford, MS 38677 (United States); Torun, Y [Illinois Institute of Technology, Chicago, IL 60616 (United States)

    2003-08-01

    A muon cooling channel calls for very high accelerating gradient RF structures to restore the energy lost by muons in the absorbers. The RF structures have to be operated in a strong magnetic field and thus the use of superconducting RF cavities is excluded. To achieve a high shunt impedance while maintaining a large enough aperture to accommodate a large transverse emittance muon beam, the cavity design adopted is a pillbox-like geometry with thin Be foils to terminate the electromagnetic field at the cavity iris. The possibility of using grids of thin-walled metallic tubes for the termination is also being explored. Many of the RF-related issues for muon cooling channels are being studied both theoretically and experimentally using an 805 MHz cavity that has a pillbox-like geometry with thin Be windows to terminate the cavity aperture. The design and performance of this cavity are reported here. High-power RF tests of the 805 MHz cavity are in progress at Lab G in Fermilab. The cavity has exceeded its design gradient of 30 MV m{sup -1}, reaching 34 MV m{sup -1} without external magnetic field. No surface damage was observed at this gradient. The cavity is currently under conditioning at Lab G with an external magnetic field of 2.5 T. We also present here a 201 MHz cavity design for muon cooling channels. The proposed cavity design is also suitable for use in a proof-of-principle muon ionization cooling experiment.

  9. Assessing emergency planning zone for new nuclear power plant considering risk of extreme external events

    Science.gov (United States)

    Alzbutas, Robertas

    2015-04-01

    In general, the Emergency Planning Zones (EPZ) are defined as well as plant site and arrangement structures are designed to minimize the potential for natural and manmade hazards external to the plant from affecting the plant safety related functions, which can affect nearby population and environment. This may include consideration of extreme winds, fires, flooding, aircraft crash, seismic activity, etc. Thus the design basis for plant and site is deeply related to the effects of any postulated external events and the limitation of the plant capability to cope with accidents i.e. perform safety functions. It has been observed that the Probabilistic Safety Assessment (PSA) methodologies to deal with EPZ and extreme external events have not reached the same level of maturity as for severe internal events. The design basis for any plant and site is deeply related to the effects of any postulated external events and the limitation of the plant capability to cope with accidents i.e. perform safety functions. As a prime example of an advanced reactor and new Nuclear Power Plant (NPP) with enhanced safety, the International Reactor Innovative and Secure (IRIS) and Site selection for New NPP in Lithuania had been considered in this work. In the used Safety-by-Design™ approach, the PSA played obviously a key role; therefore a Preliminary IRIS PSA had been developed along with the design. For the design and pre-licensing process of IRIS the external events analysis included both qualitative evaluation and quantitative assessment. As a result of preliminary qualitative analyses, the external events that were chosen for more detailed quantitative scoping evaluation were high winds and tornadoes, aircraft crash, and seismic events. For the site selection in Lithuania a detail site evaluation process was performed and related to the EPZ and risk zoning considerations. In general, applying the quantitative assessment, bounding site characteristics could be used in order to

  10. The external costs of nuclear power: Ex ante damages and lay risks

    Energy Technology Data Exchange (ETDEWEB)

    Krupnick, A.J.; Markandya, A.; Nickell, E.

    1993-12-01

    Interest has been growing in embedding the external costs of fuel cycles resulting in electricity generation into prices. In any attempt to internalize these costs for the nuclear cycle, the remost but real possibilities of accidents and the wide gap between lay perceptions and expert assessments of such risks must be taken into account. This paper discusses this including the following topics: An expected utility model of power plant operations/accident risks; simulation; comparison of experts versus lay risks; comparison of experts versus lay risk literature; simulation of expert versus lay risks. Current practice in estimating the damages from accidents at nuclear power plants appear to ignore significant features of the problem from the perspective of economic analysis. Individual aversion to risk, the exante perspective in decision making under uncertainty, and lay risk perception are all conceptually important elements of a damage estimate that accords with observation of behavior and the theory that underlies it but that are ignored by common practice. 18 refs., 1 tab.

  11. Environmental externalities: Applying the concept to Asian coal-based power generation. [Includes external environmental and societal costs and methods of evaluating them

    Energy Technology Data Exchange (ETDEWEB)

    Szpunar, C.B.; Gillette, J.L.

    1993-03-01

    This report examines the concept of environmental externality. It discusses various factors -- the atmospheric transformations, relationship of point-source emissions to ambient air quality, dose-response relationships, applicable cause-and-effect principles, and risk and valuation research -- that are considered by a number of state utilities when they apply the environmental externality concept to energy resource planning. It describes a methodology developed by Argonne National Laboratory for general use in resource planning, in combination with traditional methods that consider the cost of electricity production. Finally, it shows how the methodology can be applied in Indonesia, Thailand, and Taiwan to potential coal-fired power plant projects that will make use of clean coal technologies.

  12. European protection principles against external hazards by means of Emergency Power Supply and Control Safety System Building in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Gallinat, Dipl Ing [Max Aicher Engineering GmbH, Freilassing (Germany)

    2016-10-15

    One of the most important nuclear power plant safety requirements is a redundant and independent power system. This requires such a design of emergency power systems that failure of one will not adversely impact the other. External hazards of natural origin or linked to human activity could potentially affect plant safety. The general objective of the design provisions is to ensure that the safety functions of the systems and components required to return the plant to a safe shutdown state and to prevent and limit radioactive release are not adversely affected. As external hazards are site dependent, Technical Guidelines specify that 'it is not necessary to take all of the hazards in a standardized design; such external hazards as external flooding, drought, ice formation and toxic, corrosive or combustible gases may be dealt with only for a specific plant, on a plant specific basis'. In accordance with the Technical Guidelines, external hazards are taken into consideration at the design stage consistently with internal events or hazards. The basic design principle is to protect against external hazards in accordance with the Technical Guidelines using a 'load case' procedure.

  13. Effect of surface microstructure and wettability on plasma protein adsorption to ZnO thin films prepared at different RF powers

    Energy Technology Data Exchange (ETDEWEB)

    Huang Zhanyun; Chen Min; Chen Dihu [State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou 510275 (China); Pan Shirong, E-mail: stscdh@mail.sysu.edu.c [Artificial Heart Lab, the 1st Affiliate Hospital of Sun Yat-Sen University, Guangzhou 510080 (China)

    2010-10-01

    In this paper, the adsorption behavior of plasma proteins on the surface of ZnO thin films prepared by radio frequency (RF) sputtering under different sputtering powers was studied. The microstructures and surface properties of the ZnO thin films were investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible optical absorption spectroscopy and contact angle techniques. The results show that the ZnO thin films have better orientation of the (0 0 2) peak with increasing RF power, especially at around 160 W, and the optical band gap of the ZnO films varies from 3.2 to 3.4 eV. The contact angle test carried out by the sessile drop technique denoted a hydrophobic surface of the ZnO films, and the surface energy and adhesive work of the ZnO thin films decreased with increasing sputtering power. The amounts of human fibrinogen (HFG) and human serum albumin (HSA) adsorbing on the ZnO films and reference samples were determined by using enzyme-linked immunosorbent assay (ELISA). The results show that fewer plasma proteins and a smaller HFG/HSA ratio adsorb on the ZnO thin films' surface.

  14. Effect of surface microstructure and wettability on plasma protein adsorption to ZnO thin films prepared at different RF powers.

    Science.gov (United States)

    Huang, Zhan-Yun; Chen, Min; Pan, Shi-Rong; Chen, Di-Hu

    2010-10-01

    In this paper, the adsorption behavior of plasma proteins on the surface of ZnO thin films prepared by radio frequency (RF) sputtering under different sputtering powers was studied. The microstructures and surface properties of the ZnO thin films were investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible optical absorption spectroscopy and contact angle techniques. The results show that the ZnO thin films have better orientation of the (0 0 2) peak with increasing RF power, especially at around 160 W, and the optical band gap of the ZnO films varies from 3.2 to 3.4 eV. The contact angle test carried out by the sessile drop technique denoted a hydrophobic surface of the ZnO films, and the surface energy and adhesive work of the ZnO thin films decreased with increasing sputtering power. The amounts of human fibrinogen (HFG) and human serum albumin (HSA) adsorbing on the ZnO films and reference samples were determined by using enzyme-linked immunosorbent assay (ELISA). The results show that fewer plasma proteins and a smaller HFG/HSA ratio adsorb on the ZnO thin films' surface.

  15. Remote RF Battery Charging

    NARCIS (Netherlands)

    Visser, H.J.; Pop, V.; Op het Veld, J.H.G.; Vullers, R.J.M.

    2011-01-01

    The design of a remote RF battery charger is discussed through the analysis and design of the subsystems of a rectenna (rectifying antenna): antenna, rectifying circuit and loaded DC-to-DC voltage (buck-boost) converter. Optimum system power generation performance is obtained by adopting a system in

  16. Computer-aided design of the RF-cavity for a high-power S-band klystron

    Science.gov (United States)

    Kant, D.; Bandyopadhyay, A. K.; Pal, D.; Meena, R.; Nangru, S. C.; Joshi, L. M.

    2012-08-01

    This article describes the computer-aided design of the RF-cavity for a S-band klystron operating at 2856 MHz. State-of-the-art electromagnetic simulation tools SUPERFISH, CST Microwave studio, HFSS and MAGIC have been used for cavity design. After finalising the geometrical details of the cavity through simulation, it has been fabricated and characterised through cold testing. Detailed results of the computer-aided simulation and cold measurements are presented in this article.

  17. ISR RF cavities

    CERN Multimedia

    1983-01-01

    In each ISR ring the radiofrequency cavities were installed in one 9 m long straight section. The RF system of the ISR had the main purpose to stack buckets of particles (most of the time protons)coming from the CPS and also to accelerate the stacked beam. The installed RF power per ring was 18 kW giving a peak accelerating voltage of 20 kV. The system had a very fine regulation feature allowing to lower the voltage down to 75 V in a smooth and well controlled fashion.

  18. A 10 dBm-25 dBm, 0.363 mm2 Two Stage 130 nm RF CMOS Power Amplifier

    Directory of Open Access Journals (Sweden)

    Shridhar R. Sahu

    2013-10-01

    Full Text Available This paper proposes a 2.4 GHz RF CMOS Power amplifier and variation in its main performance parameters i.e, output power, S-parameters and power added efficiency with respect to change in supply voltage and size of the power stage transistor. The supply voltage was varied form 1 V to 5 V and the range of output power at 1dB compression point was found to be from 10.684 dBm to 25.08 dBm respectively. The range of PAE is 16.65 % to 48.46 %. The width of the power stage transistor was varied from 150 µm to 500 µm to achieve output power of range 15.47 dBm to 20.338 dBm. The range of PAE obtained here is 29.085 % to 45.439 %. The total dimension of the layout comes out to be 0.714 * 0.508 mm2 .

  19. Studies of RF sheaths and diagnostics on IShTAR

    Energy Technology Data Exchange (ETDEWEB)

    Crombé, K., E-mail: Kristel.Crombe@UGent.be [Department of Applied Physics, Ghent University, Ghent (Belgium); LPP-ERM/KMS, Royal Military Academy, Brussels (Belgium); Devaux, S.; Faudot, E.; Heuraux, S.; Moritz, J. [YIJL, UMR7198 CNRS-Université de Lorraine, Nancy (France); D’Inca, R.; Faugel, H.; Fünfgelder, H.; Jacquot, J.; Ochoukov, R. [Max-Planck-Institut für Plasmaphysik, Garching (Germany); Louche, F.; Tripsky, M.; Van Eester, D.; Wauters, T. [LPP-ERM/KMS, Royal Military Academy, Brussels (Belgium); Noterdaeme, J.-M. [Department of Applied Physics, Ghent University, Ghent (Belgium); Max-Planck-Institut für Plasmaphysik, Garching (Germany)

    2015-12-10

    IShTAR (Ion cyclotron Sheath Test ARrangement) is a linear magnetised plasma test facility for RF sheaths studies at the Max-Planck-Institut für Plasmaphysik in Garching. In contrast to a tokamak, a test stand provides more liberty to impose the parameters and gives better access for the instrumentation and antennas. The project will support the development of diagnostic methods for characterising RF sheaths and validate and improve theoretical predictions. The cylindrical vacuum vessel has a diameter of 1 m and is 1.1 m long. The plasma is created by an external cylindrical plasma source equipped with a helical antenna that has been designed to excite the m=1 helicon mode. In inductive mode, plasma densities and electron temperatures have been characterised with a planar Langmuir probe as a function of gas pressure and input RF power. A 2D array of RF compensated Langmuir probes and a spectrometer are planned. A single strap RF antenna has been designed; the plasma-facing surface is aligned to the cylindrical plasma to ease the modelling. The probes will allow direct measurements of plasma density profiles in front of the RF antenna, and thus a detailed study of the density modifications induced by RF sheaths, which influences the coupling. The RF antenna frequency has been chosen to study different plasma wave interactions: the accessible plasma density range includes an evanescent and propagative behaviour of slow or fast waves, and allows the study of the effect of the lower hybrid resonance layer.

  20. 78 FR 18253 - Request for Information on Evaluating New Products for the Battery Chargers and External Power...

    Science.gov (United States)

    2013-03-26

    ... Part 430 RIN 1904-AB57 Request for Information on Evaluating New Products for the Battery Chargers and... energy conservation standard levels for battery chargers if it is determined that new energy conservation... energy conservation standards for classes of battery chargers and external power supplies....

  1. 10 CFR Appendix Z to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of External Power Supplies

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Uniform Test Method for Measuring the Energy Consumption... Appendix Z to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of External Power Supplies 1. Scope: This appendix covers the test requirements used to measure energy consumption...

  2. Internalisation of external cost in the power generation sector: Analysis with Global Multi-regional MARKAL model

    Energy Technology Data Exchange (ETDEWEB)

    Peter Rafaj; Socrates Kypreos [Paul Scherrer Institute, Villigen-PSI (Switzerland). Energy Economics Modelling Group, General Energy Department

    2007-02-15

    The Global MARKAL-Model (GMM), a multi-regional 'bottom-up' partial equilibrium model of the global energy system with endogenous technological learning, is used to address impacts of internalisation of external costs from power production. This modelling approach imposes additional charges on electricity generation, which reflect the costs of environmental and health damages from local pollutants (SO{sub 2}, NOx) and climate change, wastes, occupational health, risk of accidents, noise and other burdens. Technologies allowing abatement of pollutants emitted from power plants are rapidly introduced into the energy system, for example, desulphurisation, NOx removal, and CO{sub 2} scrubbers. The modelling results indicate substantial changes in the electricity production system in favour of natural gas combined cycle, nuclear power and renewables induced by internalisation of external costs and also efficiency loss due to the use of scrubbers. Structural changes and fuel switching in the electricity sector result in significant reduction of emissions of both local pollution and CO{sub 2} over the modelled time period. Strong decarbonisation impact of internalising local externalities suggests that ancillary benefits can be expected from policies directly addressing other issues then CO{sub 2} mitigation. Finally, the detailed analysis of the total generation cost of different technologies points out that inclusion of external cost in the price of electricity increases competitiveness of non-fossil generation sources and fossil power plants with emission control. 28 refs., 13 figs., 6 tabs.

  3. Internalisation of external cost in the power generation sector: Analysis with Global Multi-regional MARKAL model

    Energy Technology Data Exchange (ETDEWEB)

    Rafaj, Peter [Energy Economics Modelling Group, General Energy Department, Paul Scherrer Institute, CH-5232. Villigen-PSI (Switzerland)]. E-mail: Peter.Rafaj@psi.ch; Kypreos, Socrates [Energy Economics Modelling Group, General Energy Department, Paul Scherrer Institute, CH-5232. Villigen-PSI (Switzerland)]. E-mail: Socrates.Kypreos@psi.ch

    2007-02-15

    The Global MARKAL-Model (GMM), a multi-regional 'bottom-up' partial equilibrium model of the global energy system with endogenous technological learning, is used to address impacts of internalisation of external costs from power production. This modelling approach imposes additional charges on electricity generation, which reflect the costs of environmental and health damages from local pollutants (SO{sub 2}, NO {sub x} ) and climate change, wastes, occupational health, risk of accidents, noise and other burdens. Technologies allowing abatement of pollutants emitted from power plants are rapidly introduced into the energy system, for example, desulphurisation, NO {sub x} removal, and CO{sub 2} scrubbers. The modelling results indicate substantial changes in the electricity production system in favour of natural gas combined cycle, nuclear power and renewables induced by internalisation of external costs and also efficiency loss due to the use of scrubbers. Structural changes and fuel switching in the electricity sector result in significant reduction of emissions of both local pollution and CO{sub 2} over the modelled time period. Strong decarbonisation impact of internalising local externalities suggests that ancillary benefits can be expected from policies directly addressing other issues then CO{sub 2} mitigation. Finally, the detailed analysis of the total generation cost of different technologies points out that inclusion of external cost in the price of electricity increases competitiveness of non-fossil generation sources and fossil power plants with emission control00.

  4. 新的射频功放预失真线性化方法%New Predistortion Method for RF Power Amplifier Linearization

    Institute of Scientific and Technical Information of China (English)

    詹鹏; 秦开宇; 蔡顺燕

    2011-01-01

    This paper proves that the sequence of two memoryless nonlinear systems, predistorter and RF power amplifier, is commutative through theoretical derivation. For the disadvantages of frequently used predistortion structures, this paper proposes a new predistortion structure combining direct learning structure with indirect learning structure, which is simple and easy to implement The RF power amplifier predistortion linearization method is extended to the situation with memory effect Simulation results show the correctness of this predistortion linearization method. Its linearization performance is better than that using the direct inverse indirect learning structure.%理论推导证明了预失真器和射频功放两个无记忆的非线性系统的顺序可交换,针对常用的预失真学习结构的不足,提出了将直接型和间接型相结合的新预失真学习结构,该方法简单且易实现,并将该射频功放预失真线性化方法推广到了有记忆效应的情况.仿真结果表明,所提出的预失真线性化方法可行,其线性化性能优于采用直接逆间接学习结构的情况.

  5. 5.2-GHz RF Power Harvester in 0.18-/spl mu/m CMOS for Implantable Intraocular Pressure Monitoring

    KAUST Repository

    Ouda, Mahmoud H.

    2013-04-17

    A first fully integrated 5.2-GHz CMOS-based RF power harvester with an on-chip antenna is presented in this paper. The design is optimized for sensors implanted inside the eye to wirelessly monitor the intraocular pressure of glaucoma patients. It includes a five-stage RF rectifier with an on-chip antenna, a dc voltage limiter, two voltage sensors, a low dropout voltage regulator, and MOSCAP based on-chip storage. The chip has been designed and fabricated in a standard 0.18-μm CMOS technology. To emulate the eye environment in measurements, a custom test setup is developed that comprises Plexiglass cavities filled with saline solution. Measurements in this setup show that the proposed chip can be charged to 1 V wirelessly from a 5-W transmitter 3 cm away from the harvester chip. The energy that is stored on the 5-nF on-chip MOSCAP when charged to 1 V is 2.5 nJ, which is sufficient to drive an arbitrary 100-μW load for 9 μs at regulated 0.8 V. Simulated efficiency of the rectifier is 42% at -7 dBm of input power.

  6. Occupational RF Exposures (invited paper)

    Energy Technology Data Exchange (ETDEWEB)

    Jokela, K.; Puranen, L

    1999-07-01

    Potentially adverse levels of RF electromagnetic fields, exceeding the present limits for occupational exposure, arise near industrial high frequency (HF) heaters, high power broadcast antennas, and high power radar antennas. Other significant emitters of RF fields in the occupational environment are radiotelephones, induction heaters, short-wave and microwave therapy devices, base station antennas, magnetic resonance imaging devices, microwave ovens, and industrial microwave heaters. In terms of the intensity and duration of the exposure as well as the number of exposed workers, the HF sealers, particularly plastic sealers, constitute the most significant RF radiation safety problem in the working environment. (author)

  7. Study of high pressure gas filled RF cavities for muon collider

    CERN Document Server

    Yonehara, Katsuya

    2015-01-01

    Muon collider is a considerable candidate of the next-generation high-energy lepton collider machine. Operating an RF cavity in a multi-Tesla magnet is a critical requirement in a muon accelerator and a cooling channel. However, the maximum RF gradient in a vacuum RF cavity is strongly limited by an external magnetic field. Dense hydrogen gas filled RF cavity has been proposed since it is functional of generating a high RF accelerating gradient in a strong magnetic field and making an ionization cooling process at the same time. A critical issue of the cavity is a beam- induced plasma that consumes a considerable amount of RF power. The gas filled RF test cell was made and measured the RF loading due to a beam-induced plasma by using an intense proton beam at Fermilab. By doping an electronegative gas in dense hydrogen, the plasma loading effect is significantly mitigated. The result shows that the cavity is functional with a muon collider beam. Recent progress is shown in this presentation.

  8. Characteristics of a high-power RF source of negative hydrogen ions for neutral beam injection into controlled fusion devices

    Science.gov (United States)

    Abdrashitov, G. F.; Belchenko, Yu. I.; Gusev, I. A.; Ivanov, A. A.; Kondakov, A. A.; Sanin, A. L.; Sotnikov, O. Z.; Shikhovtsev, I. V.

    2017-01-01

    An injector of hydrogen atoms with an energy of 0.5-1 MeV and equivalent current of up to 1.5 A for purposes of controlled fusion research is currently under design at the Budker Institute of Nuclear Physics, Siberian Branch, Russian Academy of Sciences. Within this project, a multiple-aperture RF surface-plasma source of negative hydrogen ions is designed. The source design and results of experiments on the generation of a negative ion beam with a current of >1 A in the long-pulse mode are presented.

  9. Self-induced steady-state magnetic field in the negative ion sources with localized rf power deposition

    Energy Technology Data Exchange (ETDEWEB)

    Shivarova, A.; Todorov, D., E-mail: dimitar-tdrv@phys.uni-sofia-bg; Lishev, St. [Faculty of Physics, Sofia University, BG-1164 Sofia (Bulgaria)

    2016-02-15

    The study is in the scope of a recent activity on modeling of SPIDER (Source for Production of Ions of Deuterium Extracted from RF plasma) which is under development regarding the neutral beam injection heating system of ITER. The regime of non-ambipolarity in the source, established before, is completed here by introducing in the model the steady state magnetic field, self-induced in the discharge due to the dc current flowing in it. Strong changes in the discharge structure are reported.

  10. Protection of Accelerator Hardware: RF systems

    CERN Document Server

    Kim, S-H

    2016-01-01

    The radio-frequency (RF) system is the key element that generates electric fields for beam acceleration. To keep the system reliable, a highly sophisticated protection scheme is required, which also should be designed to ensure a good balance between beam availability and machine safety. Since RF systems are complex, incorporating high-voltage and high-power equipment, a good portion of machine downtime typically comes from RF systems. Equipment and component damage in RF systems results in long and expensive repairs. Protection of RF system hardware is one of the oldest machine protection concepts, dealing with the protection of individual high-power RF equipment from breakdowns. As beam power increases in modern accelerators, the protection of accelerating structures from beam-induced faults also becomes a critical aspect of protection schemes. In this article, an overview of the RF system is given, and selected topics of failure mechanisms and examples of protection requirements are introduced.

  11. Effect of RF powers on microstructural characteristics and optical properties of nc-Si ~ H thin films by RF-PECVD%射频功率对RF-PECVD法制备纳米硅薄膜结构特征和光学特性的影响

    Institute of Scientific and Technical Information of China (English)

    娄建忠; 李钗; 张二鹏; 马蕾; 江子荣; 王峰; 闫小兵

    2012-01-01

    利用射频等离子体增强型化学气相沉积(RF-PECVD)工艺,以SiH4和H2作为反应气体源,在石英衬底上制备了氢化纳米硅(nc-Si∶H)薄膜。其中衬底温度为250℃,H2稀释比为99%,反应压强为133Pa和射频功率为20~60W。采用α-台阶仪、X射线衍射仪(XRD)、Raman光谱仪、傅立叶变换红外光谱仪(FT-IR)和紫外-可见光分光光度计等对薄膜的结构特征和光学特性进行了测试研究。结果表明,随着射频功率的增大,nc-Si∶H薄膜的沉积速率增加,晶化率提高,晶粒尺寸增大和氢含量减小,同时薄膜的吸收系数增强,光学带隙变窄,结构有序性增强和带尾态宽度减小。%The hydrogenated nanocrystalline silicon (nc-Si · H) films were fabricated on quartz substrates by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) method with the substrate temperature of 250℃, H2 dilution ratio of 99%, the reaction pressure of 133Pa and RF power of 20-60W, using Sill4 and H2 as the gas source. The microstructures and optical properties of thin films were studied by alpha-step instru- ment, X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR) and UV-Vis spectrophotometer. The results show that, with the increasing of RF power, the nc-Si : H deposition rate increased, the crystallization rate and grain size also increased, and the hydrogen content would decrease. Simultaneously, the absorption coefficient of the films was enhanced, the optical band gap became narrow, the structural order was enhanced and the width of the band tail would decrease.

  12. Environmental externalities: An ASEAN application to coal-based power generation. Extract

    Energy Technology Data Exchange (ETDEWEB)

    Szpunar, C.B.; Gillette, J.L.

    1992-06-01

    Significant benefits to human health that result from emissions control programs may justify the costs of pollution control policies. Many scientists, economists, risk analysts, and policymakers believe that comparisons of the benefits with the costs of pollution control demonstrate that the US stationary source, air emissions control program is justified. This justification is based upon pronounced benefits to human health, especially from controlling suspended particulates and sulfur compounds. Market decisions are usually made on the basis of a consideration of traditional costs such as capital, operating and maintenance, fuel costs, and fixed charges. Social costs, which could be significant, are not incorporated explicitly into such decisions. These social costs could result in a net reduction in the welfare of individuals, and of society as a whole. Because these social costs and their effects are not represented in the price of energy, individual have no way to explicitly value them; hence, they remain unaccounted for in market decisions. By accounting for external costs, the selection of energy sources and production of energy products can lead to and equilibrium, where the total cost of energy and energy products, together with resulting social costs, can be brought to an economic minimum. The concept of an air emissions control program is of interest to the ASEAN countries (Brunei, Indonesia, Malaysia, the Philippines, Singapore, and Thailand) and their governments, especially if such a program could be justified in cost-benefit terms and shown to be directly applicable to ASEAN conditions. It is the intent of the effort described herein to demonstrate that technical options are available to control emissions from coal-based, electric power plants and that that costs of these options may be justified in cost-benefit terms.

  13. Optimal RF Systems for Lightly Loaded Superconducting Structures

    CERN Document Server

    Zwart, Townsend; Graves, William S; Wang, D; Zolfaghari, Abbi

    2004-01-01

    Recent developments in the field of RF accelerators have created a demand for power amplifiers that can support very high accelerating gradients, 15-25 MV/m, in superconducting structures with extremely low losses. Free electron lasers (FEL’s) with modest beam current, I< 10 uA, or based on energy recovery linacs (ERL’s) may have intrinsic power demands of less than 1 kW/m. We present the design of an amplifier and external tuner system that will efficiently meet this requirement. The RF amplifier, an Inductive Output Tube (IOT), offers high AC/RF efficiency, flexible power output and switching capability without the need for external modulation. The tuner circuit makes use of low loss ferrite phase shifters to create a moderate quality standing wave (Q~100-1000) between the amplifier and the superconducting cavity. An alternative design based on a shorter cavity structure and employing solid state amplifiers is also presented. The expected performance characteristics of both systems are described.

  14. An RF input coupler for a superconducting single cell cavity

    Energy Technology Data Exchange (ETDEWEB)

    Fechner, B.; Ouchi, Nobuo; Kusano, Joichi; Mizumoto, Motoharu; Mukugi, Ken [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Krawczyk, F.

    1999-03-01

    Japan Atomic Energy Research Institute proposes a high intensity proton accelerator for the Neutron Science Project. A superconducting linac is a main option for the high energy part of the accelerator. Design and development work for the superconducting accelerating cavities (resonant frequency of 600 MHz) is in progress. Superconducting cavities have an advantage of very high accelerating efficiency because RF wall loss is very small and much of the RF power fed to the cavity is consumed for the beam acceleration. On the other hand, an RF input coupler for the superconducting cavity has to be matched to the beam loading. Therefore, estimation of coupling coefficient or external quality factor (Qext) of the RF input coupler is important for the design of the couplers. In this work, Qext`s were calculated by the electromagnetic analysis code (MAFIA) and were compared with those by the measurements. A {beta} (ratio of the particle velocity to the light velocity) = 0.5 single-cell cavity with either axial coupler or side coupler was used in this work. In the experiments, a model cavity made by copper is applied. Both 2- and 3-dimensional calculations were performed in the axial coupler geometry and the results were compared. The agreements between calculated and measured values are good and this method for calculation of Qext is confirmed to be proper for the design of the RF input couplers. (author)

  15. Study of a power coupler for superconducting RF cavities used in high intensity proton accelerator; Etude et developpement d'un coupleur de puissance pour les cavites supraconductrices destinees aux accelerateurs de protons de haute intensite

    Energy Technology Data Exchange (ETDEWEB)

    Souli, M

    2007-07-15

    The coaxial power coupler needed for superconducting RF cavities used in the high energy section of the EUROTRANS driver should transmit 150 kW (CW operation) RF power to the protons beam. The calculated RF and dielectric losses in the power coupler (inner and outer conductor, RF window) are relatively high. Consequently, it is necessary to design very carefully the cooling circuits in order to remove the generated heat and to ensure stable and reliable operating conditions for the coupler cavity system. After calculating all type of losses in the power coupler, we have designed and validated the inner conductor cooling circuit using numerical simulations results. We have also designed and optimized the outer conductor cooling circuit by establishing its hydraulic and thermal characteristics. Next, an experiment dedicated to study the thermal interaction between the power coupler and the cavity was successfully performed at CRYOHLAB test facility. The critical heat load Qc for which a strong degradation of the cavity RF performance was measured leading to Q{sub c} in the range 3 W-5 W. The measured heat load will be considered as an upper limit of the residual heat flux at the outer conductor cold extremity. A dedicated test facility was developed and successfully operated for measuring the performance of the outer conductor heat exchanger using supercritical helium as coolant. The test cell used reproduces the realistic thermal boundary conditions of the power coupler mounted on the cavity in the cryo-module. The first experimental results have confirmed the excellent performance of the tested heat exchanger. The maximum residual heat flux measured was 60 mW for a 127 W thermal load. As the RF losses in the coupler are proportional to the incident RF power, we can deduce that the outer conductor heat exchanger performance is continued up to 800 kW RF power. Heat exchanger thermal conductance has been identified using a 2D axisymmetric thermal model by comparing

  16. RF transformer

    Science.gov (United States)

    Smith, James L.; Helenberg, Harold W.; Kilsdonk, Dennis J.

    1979-01-01

    There is provided an improved RF transformer having a single-turn secondary of cylindrical shape and a coiled encapsulated primary contained within the secondary. The coil is tapered so that the narrowest separation between the primary and the secondary is at one end of the coil. The encapsulated primary is removable from the secondary so that a variety of different capacity primaries can be utilized with one secondary.

  17. A Green's function approach to local rf heating in interventional MRI.

    Science.gov (United States)

    Yeung, C J; Atalar, E

    2001-05-01

    Current safety regulations for local radiofrequency (rf) heating, developed for externally positioned rf coils, may not be suitable for internal rf coils that are being increasingly used in interventional MRI. This work presents a two-step model for rf heating in an interventional MRI setting: (1) the spatial distribution of power in the sample from the rf pulse (Maxwell's equations); and (2) the transformation of that power to temperature change according to thermal conduction and tissue perfusion (tissue bioheat equation). The tissue bioheat equation is approximated as a linear, shift-invariant system in the case of local rf heating and is fully characterized by its Green's function. Expected temperature distributions are calculated by convolving (averaging) transmit coil specific absorption rate (SAR) distributions with the Green's function. When the input SAR distribution is relatively slowly varying in space, as is the case with excitation by external rf coils, the choice of averaging methods makes virtually no difference on the expected heating as measured by temperature change (deltaT). However, for highly localized SAR distributions, such as those encountered with internal coils in interventional MRI, the Green's function method predicts heating that is significantly different from the averaging method in current regulations. In our opinion, the Green's function method is a better predictor since it is based on a physiological model. The Green's function also elicits a time constant and scaling factor between SAR and deltaT that are both functions of the tissue perfusion rate. This emphasizes the critical importance of perfusion in the heating model. The assumptions made in this model are only valid for local rf heating and should not be applied to whole body heating.

  18. Acute effects of dynamic stretching exercise on power output during concentric dynamic constant external resistance leg extension

    OpenAIRE

    YAMAGUCHI, TAICHI; Ishii, Kojiro; Yamanaka, Masanori; YASUDA, KAZUNORI

    2007-01-01

    AbstractThe purpose of the present study was to clarify the acute effect of dynamic stretching exercise on muscular performance during concentric dynamic constant external resistance (DCER, formally called isotonic) muscle actions under various loads. Concentric DCER leg extension power outputs were measured in 12 healthy male students after 2 types of pretreatment. The pre- treatments were: (a) dynamic stretching treatment including 2 types of dynamic stretching exercises of leg extensors an...

  19. RF Pulsed Heating

    Energy Technology Data Exchange (ETDEWEB)

    Pritzkau, David P.

    2002-01-03

    RF pulsed heating is a process by which a metal is heated from magnetic fields on its surface due to high-power pulsed RF. When the thermal stresses induced are larger than the elastic limit, microcracks and surface roughening will occur due to cyclic fatigue. Pulsed heating limits the maximum magnetic field on the surface and through it the maximum achievable accelerating gradient in a normal conducting accelerator structure. An experiment using circularly cylindrical cavities operating in the TE{sub 011} mode at a resonant frequency of 11.424 GHz is designed to study pulsed heating on OFE copper, a material commonly used in normal conducting accelerator structures. The high-power pulsed RF is supplied by an X-band klystron capable of outputting 50 MW, 1.5 {micro}s pulses. The test pieces of the cavity are designed to be removable to allow testing of different materials with different surface preparations. A diagnostic tool is developed to measure the temperature rise in the cavity utilizing the dynamic Q change of the resonant mode due to heating. The diagnostic consists of simultaneously exciting a TE{sub 012} mode to steady-state in the cavity at 18 GHz and measuring the change in reflected power as the cavity is heated from high-power pulsed RF. Two experimental runs were completed. One run was executed at a calculated temperature rise of 120 K for 56 x 10{sup 6} pulses. The second run was executed at a calculated temperature rise of 82 K for 86 x 10{sup 6} pulses. Scanning electron microscope pictures show extensive damage occurring in the region of maximum temperature rise on the surface of the test pieces.

  20. A high-linearity SiGe RF power amplifier for 3G and 4G small basestations

    OpenAIRE

    Johansson, Ted; Solati, Noora; Fritzin, Jonas

    2012-01-01

    This article presents the design and evaluation of a linear 3.3V SiGe power amplifier for 3G and 4G femtocells with 18dBm modulated output power at 2140 MHz. Different biasing schemes to achieve high linearity with low standby current were studied. The adjacent channel power ratio linearity performance with wide-band code division multiple access (3G) and long term evolution (4G) downlink signals were compared and differences analysed and explained.

  1. Quantification of risk considering external events on the change of allowed outage time and the preventive maintenance during power operation

    Energy Technology Data Exchange (ETDEWEB)

    Kang, D. J.; Kim, K. Y.; Yang, J. E

    2001-03-01

    In this study, for the major safety systems of Ulchin Units 3/4, we quantify the risk on the change of AOT and the PM during power operation to identify the effects on the results of external events PSA when nuclear power plant changes such as allowed outage time are requested. The systems for which the risks on the change of allowed outage time are quantified are High Pressure Safety Injection System (HPSIS), Containment Spray System (CSS), and Emergency Diesel Generator (EDG). The systems for which the risks on the PM during power operation are Low Pressure Safety Injection System (LPSIS), CSS, EDG, Essential Service Water System (ESWS). Following conclusions can be obtained through this study: 1)The increase of core damage frequency ({delta}CDF) on the change of AOT and the conditional core damage probability (CCDP) on the on-line PM of each system are differently quantified according to the cases of considering only internal events or only external events. . 2)It is expected that the quantification of risk including internal and external events is advantageous for the licensee of NPP if the regulatory acceptance criteria for the technical specification changes are relatively set up. However, it is expected to be disadvantageous for the licensee if the acceptance criteria are absolutely set up. 3)It is expected that the conduction on the quantification of only a fire event is sufficient when the quantification of external events PSA model is required for the plant changes of Korea Standard NPPs. 4)It is expected that the quantification of the increase of core damage frequency and the incremental conditional core damage probability on technical specification changes are not needed if the quantification results of those considering only internal events are below regulatory acceptance criteria and the external events PSA results are not greatly affected by the system availability. However, it is expected that the quantification of risk considering external events

  2. Improving RF Transmit Power and Received Signal Strength in 2.4 GHz ZigBee Based Active RFID System with Embedded Method

    Science.gov (United States)

    Po'ad, F. A.; Ismail, W.; Jusoh, J. F.

    2017-08-01

    This paper describes the experiments and analysis conducted on 2.4 GHz embedded active Radio Frequency Identification (RFID) - Wireless Sensor Network (WSN) based system that has been developed for the purposes of location tracking and monitoring in indoor and outdoor environments. Several experiments are conducted to test the effectiveness and performance of the developed system and two of them is by measuring the Radio Frequency (RF) transmitting power and Received Signal Strength (RSS) to prove that the embedded active RFID tag is capable to generate higher transmit power during data transmission and able to provide better RSS reading compared to standalone RFID tag. Experiments are carried out on two RFID tags which are active RFID tag embedded with GPS and GSM (ER2G); and standalone RFID tag communicating with the same active RFID reader. The developed ER2G contributes 12.26 % transmit power and 6.47 % RSS reading higher than standalone RFID tag. The results conclude that the ER2G gives better performance compared to standalone RFID tag and can be used as guidelines for future design improvements.

  3. Externalities of biomass based electricity production compared to power generation from coal in the Netherlands

    NARCIS (Netherlands)

    Faaij, A.; Meuleman, B.

    2006-01-01

    Externalities of electricity production from biomass and coal are investigated and compared for the Dutch context. Effects on economic activity and employment are investigated with help of Input/Output and multiplier tables. Valuations of damage from emissions to air are based on generic data from o

  4. Sociology of Knowledge and Production of Normative Power in the European Union’s External Actions

    DEFF Research Database (Denmark)

    Manners, Ian James

    2015-01-01

    pole in the coming multipolar world, have dichotomised the advocacy of policy-making and the analysis of knowledge production of EU external actions. The article sets out, through an examination of the interlinking of policy-making and policy analysis, how such false dichotomies weaken the sociology...

  5. Sociology of Knowledge and Production of Normative Power in the European Union’s External Actions

    DEFF Research Database (Denmark)

    Manners, Ian James

    2015-01-01

    pole in the coming multipolar world, have dichotomised the advocacy of policy-making and the analysis of knowledge production of EU external actions. The chapter sets out, through an examination of the interlinking of policy-making and policy analysis, how such false dichotomies weaken the sociology...

  6. Green high-power tunable external-cavity GaN diode laser at 515 nm

    DEFF Research Database (Denmark)

    Chi, Mingjun; Jensen, Ole Bjarlin; Petersen, Paul Michael

    2016-01-01

    A 480 mW green tunable diode laser system is demonstrated for the first time to our knowledge. The laser system is based on a GaN broad-area diode laser and Littrow external-cavity feedback. The green laser system is operated in two modes by switching the polarization direction of the laser beam ...

  7. A 5.2 GHz RF combined power amplifier with fully integrated on-chip impedance matching Wilkinson power combiner and splitter

    OpenAIRE

    Kaymaksüt, Ercan; Kaymaksut, Ercan

    2008-01-01

    In this thesis a 5.2 GHz combined power amplifier is designed for Wireless Local Area Network (WLAN) application. A new on-chip power combining technique by using impedance matching Wilkinson power divider circuits will be presented. Two impedance matching Wilkinson power dividers are employed for matching the input and output impedances of the amplifier to 50 (omega)Ω as well as splitting the input power into two amplifiers and combining their output powers. A 5.2 GHz fully integrated class-...

  8. External Cost Assessment of Nuclear Power Plant Accident considering Public Risk Aversion Behavior: the Korean Case

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Hun; Kang, Hyun Gook [KAIST, Daejeon (Korea, Republic of)

    2016-05-15

    The conventional approach for monetary valuation of NPP accident consequence consists of calculating the expected value of various accident scenarios. However, the main criticism of the conventional approach is that there is a discrepancy between the social acceptability of the risk and the estimated expected value of NPP accident. Therefore, an integrated framework for the estimation of the external cost associated with an NPP accident considering the public risk aversion behavior was proposed in this study based on the constructed theoretical framework for estimating both the value of statistical life (VSL) and the risk aversion coefficient associated with an NPP accident to take account of the accident cost into the unit electricity generation cost of NPP. To estimate both parameters, an individual-level survey was conducted on a sample of 1,364 participants in Korea. Based on the collected survey responses, both parameters were estimated based on the proposed framework and the external cost of NPP accident was estimated based on the consequence analysis and considering the direct cost factors for NPP accident. Internalization of external costs into the comprehensive energy production cost has been considered as a potentially efficient policy instrument for a more sustainable energy supply and use. However, the internalization of externalities, such as public health damage, have raised a number of generic policy issues in a nuclear energy sector, with specific challenges resulting from the distinct characteristics of external cost estimation. Especially, the major challenge remained to address the public safety concerns regarding a nuclear accident, which can be specified as low-probability high-consequence accident, driven by the aspects of public risk aversion.

  9. The dependence of the sporicidal effects on the power and pressure of RF-generated plasma processes.

    Science.gov (United States)

    Lassen, Klaus S; Nordby, Bolette; Grün, Reinar

    2005-07-01

    The sporicidal effect of 20 different radio-frequency plasma processes produced by combining five different gas mixtures [O(2), Ar/H(2) (50/50%), Ar/H(2) (5/95%), O(2)/H(2) (50/50%), O(2)/H(2) (95/5%)] with four power/pressure settings were tested. Sporicidal effects of oxygen-containing plasmas were dependent on power at low pressure settings but not at high pressure settings. In the absence of oxygen no power dependency was observed at either high or low pressure settings. Survivor curves obtained with the use of nonoxygen plasmas typically had a tailing tendency. Only a mixture-optimized Ar/H(2) (15/85%) plasma process was not encumbered by tailing, and produced a decimal reduction time (D value) below 2 min for Bacillus stearothermophilus spores. Scanning electron microscopy showed that a CF(4)/O(2) plasma did more damage to the substrate than the 15/85% Ar/H(2) plasma. The present results indicate that UV irradiation inactivation is swift and power and pressure independent. Additionally, it is produced at low energy. However, it is not complete. Inactivation through etching is highly power and pressure dependent; finally, inactivation by photodesorption is moderately power and pressure dependent. A sterilization process relying on this mechanism is very advantageous because it combines a highly sporicidal effect with low substrate damage.

  10. Control of electron energy distribution by the power balance of the combined inductively and capacitively coupled RF plasmas

    Science.gov (United States)

    Kim, Jin Seok; Lee, Ho-Jun; Lee, Hae June

    2016-09-01

    The control of electron energy probability function (EEPF) is important to control discharge characteristics in materials processing. For example, O radical density increases by changing the EEPF in O2 plasma, which provides high etching efficiency. The effect of the power balance between the capacitively coupled plasma (CCP) and the inductively coupled plasma (ICP) on the EEPF in Ar and O2 plasmas is investigated with a 1d3v (one-dimensional space and three-dimensional velocity domain) particle-in-cell (PIC) simulation for the combined inductively and capacitively coupled plasmas. The combined effects of the transverse electromagnetic and the longitudinal electrostatic fields are solved in PIC simulation at the same time. In a pressure range of a few mTorr, high energy electrons (>5 eV) are heated by the capacitive power in the sheath while low energy electrons (power in the bulk region. The EEPF has bi-Maxwellian distribution when the CCP power is dominant, but it changes to Maxwellian-like distribution with increasing inductive power. Finally, the EEPF changes to Druyvesteyn-like distribution when the inductive power is dominant.

  11. SPS RF cavity

    CERN Multimedia

    1974-01-01

    The main RF-system of the SPS comprises four cavities: two of 20 m length and two of 16.5 m length. They are all installed in one long straight section (LSS 3). These cavities are of the travelling-wave type operating at a centre frequency of 200.2 MHz. They are wideband, filling time about 700 ns and untuned. A power of up to 790 kW can be supplied to each giving a total accelerating voltage of about 8 MV. The power amplifiers, using tetrodes are installed in a surface building 200 m from the cavities.

  12. Rf Station For Ion Beam Staking In Hirfl-csr

    CERN Document Server

    Arbuzov, V S; Bushuev, A A; Dranichnikov, A N; Gorniker, E I; Kendjebulatov, E K; Kondakov, A A; Kondaurov, M; Kruchkov, Ya G; Krutikhin, S A; Kurkin, G Ya; Mironenko, L A; Motygin, S V; Osipov, V N; Petrov, V M; Pilan, Andrey M; Popov, A M; Rashenko, V V; Selivanov, A N; Shteinke, A R; Vajenin, N F

    2004-01-01

    BINP has developed and produced the RF station for Institute of Modern Physics (IMP), Lanzhou, China, for multipurpose accelerator complex with electron cooling. The RF station will be used for accumulation of ion beams in the main ring of the system. It was successfully tested in IMP and installed into the main accelerator ring of the complex. The RF station includes accelerating RF cavity and RF power generator with power supplies. The station works within frequency range 6.0 - 14.0 MHz, maximum voltage across the accelerating gap of the RF cavity - 20 kV. In the RF cavity the 200 VNP ferrite is utilized. A residual gas pressure in vacuum chamber does not exceed 2,5E-11 mbar. Maximum output power of the RF generator 25 kW. The data acquisition and control of the RF station is based on COMPACT - PCI bus and provides all functions of monitoring and control.

  13. Calcium-ion efflux from brain tissue: power-density versus internal field-intensity dependencies at 50-MHz RF radiation

    Energy Technology Data Exchange (ETDEWEB)

    Blackman, C.F.; Benane, S.G.; Joines, W.T.; Hollis, M.A.; House, D.E.

    1980-01-01

    In previous experiments changes were found in calcium-ion efflux from chick-brain tissue that had been exposed in vitro to 147-MHz radiation across a specific range of power densities when the field was amplitude modulated at 16 Hz. In the present study, 50-MHz radiation, similarly modulated as a sinusoid, was found to produce changes in calcium-ion efflux from chick brains exposed in vitro in a Crawford cell. Exposure conditions were optimized to broaden any power-density window and to enhance the opportunity to detect changes in the calcium-ion efflux. The results of a power-density series demonstrated two effective ranges: One spanning a range from 1.44 to 1.67 mW/cm2, and the other including 3.64 mW/cm2, which were bracketed by no-effect results at 0.72, 2.17, and 4.32 mW/cm2. peaks of positive findings are associated with near-identical rates of energy absorption: 1.4 microW/g at 147 MHz, and 1.3 microW/g at 50 MHz, which indicates that the enhanced-efflux phenomenon is more dependent on the intensity of fields in the brain than on the power density of incident radiation. In addition, the phenomenon appears to occur at multiples of some, as yet unknown, rate of radiofrequency (RF) energy absorption. Because of the extremely small increments of temperature associated with positive findings (less than 4 X 10(-4) degrees C), and the existence of more than one productive absorption rate, a solely thermal explanation appears extremely unlikely.

  14. A 3μW fully-differential RF envelope detector for ultra-low power receivers

    NARCIS (Netherlands)

    Liempd, B.W.M. van; Vidojkovic, M.; Lont, M.; Zhou, C.; Harpe, P.; Milosevic, D.; Dolmans, G.

    2012-01-01

    A fully differential envelope detector (ED) operating at 2.4GHz is designed in 90nm CMOS technology. The new design uses the common-gate topology to deal with large common-mode input signals through first-order current cancellation. Thereby, a fully differential ultra-low power super-regenerative fr

  15. Theoretical study of enhancing the piezoelectric nanogenerator's output power by optimizing the external force's shape

    Science.gov (United States)

    Xu, Qi; Qin, Yong

    2017-07-01

    The average power is one of the key parameters of piezoelectric nanogenerators (PENGs). In this paper, we demonstrate that the PENG's output can be gigantically improved by choosing driving force with an appropriate shape. When the load resistance is 100 MΩ and the driven forces have a magnitude of 19.6 nN, frequency of 10 Hz, the average power of PENG driven by square shaped force is six orders of magnitude higher than that driven by triangular shaped and sinusoidal shaped forces. These results are of importance for optimizing the average power of the PENGs in practical applications.

  16. Moscow Meson Factory DTL RF System Upgrade

    CERN Document Server

    Esin, S K; Kvasha, A I; Serov, V L

    2004-01-01

    The last paper devoted to description of the first part (DTL) RF system of Moscow Meson Factory upgrade was published in the Proceedings of PAC95 Conference in Dallas. Since then some new works directed at improvement of reliability and efficiency of the RF system were carried out. Among them there are a new powerful pulse triode “Katran” installed in the output RF power amplifiers (PA) of three channels, modifications of the anode modulator control circuit and crow-bar system, a new additional RF channel for RF supply of RFQ and some alterations in placing of the anode modulator equipment decreasing a level of interference’s at crow-bar circuits. Some new checked at MMF RF channels ideas concerning of PA tuning are of interest for people working in this sphere of activity.

  17. Inequalities and externalities of power sector. A case of Broadlands hydropower project in Sri Lanka

    Energy Technology Data Exchange (ETDEWEB)

    Gunawardena, U.A.D. Prasanthi [Department of Forestry and Environmental Science, University of Sri Jayewardenepura, Nugegoda (Sri Lanka)

    2010-02-15

    The objective of the paper is to estimate environmental externalities related to a run of river project in Sri Lanka and to investigate inequity in distribution of impacts among different social groups. Diversion of the river resulted in loss of water sports (for high-income groups both local and remote), loss of historical monuments (for remote high-income groups) and recreation losses (for local poor). Removal of forest cover leads to loss of non-timber products (for local poor) and carbon storage (for remote high- and low-income groups). Loss of home garden productivity was borne by local poor groups. Benefit of the project, generation of 145 GWh annually, was a gain for the grid connected groups. The impacts were valued using various valuation methods. The base case of the cost benefit analysis resulted in NPV of US$ 11,335,730. When distributional weights are applied for different income groups, both the sign and magnitude of net benefits change. In order to be viable, the project needs diversion of at least 9% of generated electricity to the poorest households in the country. Implications for energy policy towards reducing externality and inequality impacts are also discussed. (author)

  18. Inequalities and externalities of power sector: A case of Broadlands hydropower project in Sri Lanka

    Energy Technology Data Exchange (ETDEWEB)

    Gunawardena, U.A.D. Prasanthi, E-mail: prasanthigunawardena@yahoo.co [Department of Forestry and Environmental Science, University of Sri Jayewardenepura, Nugegoda (Sri Lanka)

    2010-02-15

    The objective of the paper is to estimate environmental externalities related to a run of river project in Sri Lanka and to investigate inequity in distribution of impacts among different social groups. Diversion of the river resulted in loss of water sports (for high-income groups both local and remote), loss of historical monuments (for remote high-income groups) and recreation losses (for local poor). Removal of forest cover leads to loss of non-timber products (for local poor) and carbon storage (for remote high- and low-income groups). Loss of home garden productivity was borne by local poor groups. Benefit of the project, generation of 145 GWh annually, was a gain for the grid connected groups. The impacts were valued using various valuation methods. The base case of the cost benefit analysis resulted in NPV of US$ 11,335,730. When distributional weights are applied for different income groups, both the sign and magnitude of net benefits change. In order to be viable, the project needs diversion of at least 9% of generated electricity to the poorest households in the country. Implications for energy policy towards reducing externality and inequality impacts are also discussed.

  19. High-Power Blue Light Generation by External Frequency Doubling of an Optical Parametric Oscillator

    Institute of Scientific and Technical Information of China (English)

    毕勇; 张鸿博; 孙志培; 包照日格图; 李惠清; 孔宇鹏; 林学春; 王桂玲; 张杰; 侯玮; 李瑞宁; 崔大复; 许祖彦; 宋立维; 章萍; 崔建峰; 樊仲维

    2003-01-01

    We report on an all-solid-state high-power quasi-continuous blue light source by the frequency doubling of a signal wave from an optical parametric oscillator(OPO).A 50-mm-long LiB3O5(LBO)crystal is used for the OPO,which is pumped by a diode-pumped Nd:YAG green laser(10kHz,50ns).Tunable blue emission in a new nonlinear crystal BiB3O6(BiBO)is obtained with a wavelength range from 450 to 495 nm.The average power of the signal output is as high as 9.3 W from 924 to 970nm.The maximum output of the blue laser with the second harmonic walk-off compensation is 1.3 W average power at 470nm for 6.2 W of OPO signal light at 940nm.

  20. RF Characterization of Niobium Films for Superconducting Cavities

    CERN Document Server

    Aull† , S; Doebert, S; Junginger, T; Ehiasarian, AP; Knobloch, J; Terenziani, G

    2013-01-01

    The surface resistance RS of superconductors shows a complex dependence on the external parameters such as temperature, frequency or radio-frequency (RF) field. The Quadrupole Resonator modes of 400, 800 and 1200 MHz allow measurements at actual operating frequencies of superconducting cavities. Niobium films on copper substrates have several advantages over bulk niobium cavities. HIPIMS (High-power impulse magnetron sputtering) is a promising technique to increase the quality and therefore the performance of niobium films. This contribution will introduce CERNs recently developed HIPIMS coating apparatus. Moreover, first results of niobium coated copper samples will be presented, revealing the dominant loss mechanisms.

  1. Tuning range and output power optimization of an external-cavity GaN diode laser at 455  nm.

    Science.gov (United States)

    Chi, Mingjun; Jensen, Ole Bjarlin; Petersen, Paul Michael

    2016-03-20

    In this paper we discuss how different feedback gratings affect the tuning range and the output power of external feedback diode laser systems. A tunable high-power narrow-spectrum external-cavity diode laser system around 455 nm is investigated. The laser system is based on a high-power GaN diode laser in a Littrow external-cavity. Both a holographic diffraction grating and a ruled diffraction grating are used as feedback elements in the external cavity. The output power, spectral bandwidth, and tunable range of the external cavity diode laser system are measured and compared with the two gratings at different injected currents. When the holographic grating is used, the laser system can be tuned over a range of 1.4 nm with an output power around 530 mW. When the ruled grating is used, the laser system can be tuned over a range of 6.0 nm with an output power around 80 mW. The results can be used as a guide for selecting gratings for external-cavity diode lasers for different requirements.

  2. Direct observation of 0.57 eV trap-related RF output power reduction in AlGaN/GaN high electron mobility transistors

    Science.gov (United States)

    Arehart, A. R.; Sasikumar, A.; Rajan, S.; Via, G. D.; Poling, B.; Winningham, B.; Heller, E. R.; Brown, D.; Pei, Y.; Recht, F.; Mishra, U. K.; Ringel, S. A.

    2013-02-01

    This paper reports direct evidence for trap-related RF output power loss in GaN high electron mobility transistors (HEMTs) grown by metal organic chemical vapor deposition (MOCVD) through increased concentration of a specific electron trap at EC-0.57 eV that is located in the drain access region, as a function of accelerated life testing (ALT). The trap is detected by constant drain current deep level transient spectroscopy (CID-DLTS) and the CID-DLTS thermal emission time constant precisely matches the measured drain lag. Both drain lag and CID-DLTS measurements show this state to already exist in pre-stressed devices, which coupled with its strong increase in concentration as a function of stress in the absence of significant increases in concentrations of other detected traps, imply its role in causing degradation, in particular knee walkout. This study reveals EC-0.57 eV trap concentration tracks degradation induced by ALT for MOCVD-grown HEMTs supplied by several commercial and university sources. The results suggest this defect has a common source and may be a key degradation pathway in AlGaN/GaN HEMTs and/or an indicator to predict device lifetime.

  3. Diamond field-effect transistors for RF power electronics: Novel NO2 hole doping and low-temperature deposited Al2O3 passivation

    Science.gov (United States)

    Kasu, Makoto

    2017-01-01

    Diamond possesses a combination of exceptional physical properties and is expected to be used as a semiconductor material in high-efficiency and high-power electronic devices. In this study, hole doping was observed when using NO2 molecules on a H-diamond surface. The activation energy of hole concentration in NO2/H-diamond was measured as 0.006 eV, and holes were fully activated at room temperature. A thermal stabilization of the hole channel was realized by passivation with an atomic-layer-deposited Al2O3 layer. The passivation method enabled the realization of a thermally stable high-performance diamond field-effect transistor (FET), which exhibited high-performance DC and RF characteristics. NO2 hole-doping and Al2O3-passivation technologies enabled reproducible measurements of MOS structure electric properties. Such technologies also facilitated observations of two-dimensional holes at the MOS interface and type-II band alignment of Al2O3/NO2/H-diamond. Additionally, the band diagram under various gate bias conditions was proposed on the basis of capacitance-voltage measurements and analysis using Poisson’s equations.

  4. The assessment of health impacts and external costs of natural gas-fired power plant of Qom.

    Science.gov (United States)

    Fouladi Fard, Reza; Naddafi, Kazem; Yunesian, Masud; Nabizadeh Nodehi, Ramin; Dehghani, Mohammad Hadi; Hassanvand, Mohammad Sadegh

    2016-10-01

    The external health damage costs of the combined cycle natural gas-fired power plant of Qom were investigated via the simplified impact pathway approach. Emitted particulate matter (PM10) and gaseous pollutants (NO x , CO, and SO2) from the power plant stack were measured The health effects and related costs were estimated by QUERI model from AirPacts according to the emissions, source and stack parameters, pollutant depletion velocities, exposure-response functions, local and regional population density, and detailed meteorological data. The results showed that the main health effect was assigned to the nitrate as restricted activity days (RAD) with 25,240 days/year. For all pollutants, the maximum health damage costs were related to the long-term mortality (49 %), restricted activity days (27 %), and chronic bronchitis (21 %). The annual health damage costs were approximately 4.76 million US$, with the cost being 0.096 US per kWh of generating electricity. Although the health damage costs of gas-fired power plant were lower than those of other heavy fuels, it seems essential to consider the health and environmental damages and focus on the emission control strategies, particularly in site selection for the new power plants and expanding the current ones.

  5. LANSCE RF System Refurbishment

    CERN Document Server

    Rees, Daniel; Kwon, Sung-il; Lyles, John T M; Lynch, Michael; Prokop, Mark; Reass, William; Tallerico, Paul J

    2005-01-01

    The Los Alamos Neutron Science Center (LANSCE) is in the planning phase of a refurbishment project that will sustain reliable facility operations well into the next decade. The LANSCE accelerator was constructed in the late 1960s and early 1970s and is a national user facility that provides pulsed protons and spallation neutrons for defense and civilian research and applications. We will be replacing all the 201 MHz RF systems and a substantial fraction of the 805 MHz RF systems and high voltage systems. The current 44 LANSCE 805 MHz, 1.25 MW klystrons have an average in-service time in excess of 110,000 hours. All 44 must be in service to operate the accelerator. There are only 9 spares left. The klystrons receive their DC power from the power system originally installed in 1960. Although this power system has been extremely reliable, gas analysis of the insulating oil is indicating age related degradation that will need attention in the next few years. This paper will provide the design details of the new R...

  6. SPS RF Accelerating Cavity

    CERN Multimedia

    1979-01-01

    This picture shows one of the 2 new cavities installed in 1978-1979. The main RF-system of the SPS comprises four cavities: two of 20 m length and two of 16.5 m length. They are all installed in one long straight section (LSS 3). These cavities are of the travelling-wave type operating at a centre frequency of 200.2 MHz. They are wideband, filling time about 700 ns and untuned. The power amplifiers, using tetrodes are installed in a surface building 200 m from the cavities. Initially only two cavities were installed, a third cavity was installed in 1978 and a forth one in 1979. The number of power amplifiers was also increased: to the first 2 MW plant a second 2 MW plant was added and by end 1979 there were 8 500 kW units combined in pairs to feed each of the 4 cavities with up to about 1 MW RF power, resulting in a total accelerating voltage of about 8 MV. See also 7412016X, 7412017X, 7411048X

  7. SPS RF Cavity

    CERN Multimedia

    1975-01-01

    The picture shows one of the two initially installed cavities. The main RF-system of the SPS comprises four cavities: two of 20 m length and two of 16.5 m length. They are all installed in one long straight section (LSS 3). These cavities are of the travelling-wave type operating at a centre frequency of 200.2 MHz. They are wideband, filling time about 700 ns and untuned. The power amplifiers, using tetrodes are installed in a surface building 200 m from the cavities. Initially only two cavities were installed, a third cavity was installed in 1978 and a forth one in 1979. The number of power amplifiers was also gradually increased: by end 1980 there were 8 500 kW units combined in pairs to feed each of the 4 cavities with up to about 1 MW RF power, resulting in a total accelerating voltage of about 8 MV. See also 7412017X, 7411048X, 7505074.

  8. Acute effects of dynamic stretching exercise on power output during concentric dynamic constant external resistance leg extension.

    Science.gov (United States)

    Yamaguchi, Taichi; Ishii, Kojiro; Yamanaka, Masanori; Yasuda, Kazunori

    2007-11-01

    The purpose of the present study was to clarify the acute effect of dynamic stretching exercise on muscular performance during concentric dynamic constant external resistance (DCER, formally called isotonic) muscle actions under various loads. Concentric DCER leg extension power outputs were measured in 12 healthy male students after 2 types of pretreatment. The pretreatments were: (a) dynamic stretching treatment including 2 types of dynamic stretching exercises of leg extensors and the other 2 types of dynamic stretching exercises simulating the leg extension motion (2 sets of 15 times each with 30-second rest periods between sets; total duration: about 8 minutes), and (b) nonstretching treatment by resting for 8 minutes in a sitting position. Loads during measurement of the power output were set to 5, 30, and 60% of the maximum voluntary contractile (MVC) torque with isometric leg extension in each subject. The power output after the dynamic stretching treatment was significantly (p after the nonstretching treatment under each load (5% MVC: 468.4 +/- 102.6 W vs. 430.1 +/- 73.0 W; 30% MVC: 520.4 +/- 108.5 W vs. 491.0 +/- 93.0 W; 60% MVC: 487.1 +/- 100.6 W vs. 450.8 +/- 83.7 W). The present study demonstrated that dynamic stretching routines, such as dynamic stretching exercise of target muscle groups and dynamic stretching exercise simulating the actual motion pattern, significantly improve power output with concentric DCER muscle actions under various loads. These results suggested that dynamic stretching routines in warm-up protocols enhance power performance because common power activities are carried out by DCER muscle actions under various loads.

  9. Productivity measurement in the presence of externalities: An example from the electric power industry

    Science.gov (United States)

    Chaston, Kelly Ann

    Traditional productivity measures have ensured that environmental regulations were seen as deterrents to productivity growth. Such measures are constructed in a manner which make this conclusion inevitable. Traditional productivity measures include the regulation-induced additions to inputs, whether qualitatively or quantitatively, while continuing to ignore the value of the pollution emitted. The measure proposed in this thesis is derived formally from a model of social welfare. With the exception of 'prices' for emitted pollutants, for which marginal damage estimates will proxy, the proposed measure relies upon market prices, which are then incorporated into a conventional Divisia framework. Data from the electricity generation industry are used to construct both the conventional and newly proposed TFP growth rates. The industry provides an ideal framework within which this growth measure can be tested. It is a large industry that affects a majority of society as it is both consumed as a final good and pervasively used as an intermediate good. The industry is also a large polluter. On an annual basis it has been responsible for approximately one-third of the emissions of carbon-dioxide, one-third of the emissions of nitrous oxides, and two-thirds of the sulfur dioxides emissions, nationally. Furthermore, performance of the proposed measure across various samples was allowed by the diversity of utilities in the industry both with respect to location and fuel mix. Incorporating the value of externalities results in a productivity growth measure which is substantially improved. The difference in calculated productivity gains between the two measures is shown to be sizable under a number of circumstances. As well, the empirical analysis offers some general lessons as to the treatment of various pollutants--it is clearly demonstrated that movement in one pollutant cannot be used to proxy movements in others, or be used as an indicator as to the bias of traditional TFP

  10. 单片集成微波/射频功率放大器技术进展%Progress in Monolithic Integrated Microwave/RF Power Amplifier

    Institute of Scientific and Technical Information of China (English)

    李强; 严利人; 周卫; 张伟

    2011-01-01

    As wireless communication market increases, monolithic integrated microwave/RF power amplifier (MMIC PA) plays a more and more important role in 3G and/or 4G systems. Traditional circuits used in mono-stage amplifiers are reviewed, together with their pros and cons. Architectures, such as the Doherty circuitry, EER (Envelope Elimination and Restoration) technology, LINC, etc. , are also discussed. Generally, these technologies may be used to improve linearity and efficiency of microwave power amplifier. Currently, some system-level linearization techniques have also been utilized. The overview may serve as a useful groundwork for those who are designing MMIC Pas.%回顾了一些用于微波单级功率放大器的传统技术方案,讨论了各自的优缺点.从电路模块的角度,总结了若干兼顾功放线性度和效率指标的典型电路拓扑形式,包括Doherty电路、包络消除与恢复(EER)技术、LINC技术等,并总结了当前主要采用的基于电路系统层面的微波射频功放线性化方案.在此基础上,列举评点了文献中一些典型功放的电路特点和性能指标,可为设计和制造人员提供有益参考.

  11. A LOW NOISE RF SOURCE FOR RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    HAYES,T.

    2004-07-05

    The Relativistic Heavy Ion Collider (RHIC) requires a low noise rf source to ensure that beam lifetime during a store is not limited by the rf system. The beam is particularly sensitive to noise from power line harmonics. Additionally, the rf source must be flexible enough to handle the frequency jump required for rebucketing (transferring bunches from the acceleration to the storage rf systems). This paper will describe the design of a Direct Digital Synthesizer (DDS) based system that provides both the noise performance and the flexibility required.

  12. Packaged, High-Power, Narrow-Linewidth Slab-Coupled Optical Waveguide External Cavity Laser (SCOWECL)

    Science.gov (United States)

    2010-12-01

    efficiency. With the 20% reflecli vity FBG, the laser ex hibi ts a threshold of 0.9 A and reaches a CW peak power of 0.37 W aI 4 A. The peak effic ...twice the photon energy . The SCOWECL is expected to find applications in free space coherent optical communications and in microwave photollic...Dai , " High effic ient and narrow linewidlh fiber laser based on fiber grat ing Fabry- Perot cavity," Frolltiers of Oploeieclrollics il/ Chinll, vol

  13. RF and microwave microelectronics packaging II

    CERN Document Server

    Sturdivant, Rick

    2017-01-01

    Reviews RF, microwave, and microelectronics assembly process, quality control, and failure analysis Bridges the gap between low cost commercial and hi-res RF/Microwave packaging technologies Engages in an in-depth discussion of challenges in packaging and assembly of advanced high-power amplifiers This book presents the latest developments in packaging for high-frequency electronics. It is a companion volume to “RF and Microwave Microelectronics Packaging” (2010) and covers the latest developments in thermal management, electrical/RF/thermal-mechanical designs and simulations, packaging and processing methods, and other RF and microwave packaging topics. Chapters provide detailed coverage of phased arrays, T/R modules, 3D transitions, high thermal conductivity materials, carbon nanotubes and graphene advanced materials, and chip size packaging for RF MEMS. It appeals to practicing engineers in the electronic packaging and high-frequency electronics domain, and to academic researchers interested in underst...

  14. Femtosecond precision measurement of laser-rf phase jitter in a photocathode rf gun

    Science.gov (United States)

    Shi, Libing; Zhao, Lingrong; Lu, Chao; Jiang, Tao; Liu, Shengguang; Wang, Rui; Zhu, Pengfei; Xiang, Dao

    2017-03-01

    We report on the measurement of the laser-rf phase jitter in a photocathode rf gun with femtosecond precision. In this experiment four laser pulses with equal separation are used to produce electron bunch trains; then the laser-rf phase jitter is obtained by measuring the variations of the electron bunch spacing with an rf deflector. Furthermore, we show that when the gun and the deflector are powered by the same rf source, it is possible to obtain the laser-rf phase jitter in the gun through measurement of the beam-rf phase jitter in the deflector. Based on these measurements, we propose an effective time-stamping method that may be applied in MeV ultrafast electron diffraction facilities to enhance the temporal resolution.

  15. A study of optical design of power-saving backlight module with external illuminance

    Science.gov (United States)

    Fang, Yi-Chin; Tzeng, Yih-Fong

    2014-05-01

    In backlight modules, the light guide plate (LGP) is a key component for performance and also facilitates access to develop LGPs on its own. In this research, we propose a newly developed method: LEDs with freeform as a lighting source, are employed to integrate and manipulate the specially designed and optimized 3D-like pattern distribution of the micro features in order to obtain the required optical characteristics at maximal performance. In this research propose the concept of Light Guide Film(LGF) at the back side of Back Light Unit(BLU). This new design may induce the exterior light ,then improve the power-saving of existent BLU. Two design models are reseated: One is design for 14 inch LCD monitor of notebook computer, which might improve 21% compared to traditional one. Another is designed for 3.5 inch LCD for mobile phone display ,which might improve 15% compared to traditional one.

  16. Controlling thermal properties of dense gas fluidized beds for concentrated solar power by internal and external solids circulation

    Science.gov (United States)

    Ammendola, Paola; Bareschino, Piero; Chirone, Riccardo; Salatino, Piero; Solimene, Roberto

    2017-06-01

    Fluidization technology displays a long record of success stories, mostly related to applications to thermal and thermochemical processes, which are fostering extension to novel and relatively unexplored fields. Application of fluidized beds to collection and thermal storage of solar radiation in Concentrated Solar Power (CSP) is one of the most promising, a field which poses challenging issues and great opportunities to fluidization scientists and technologists. The potential of this growing field calls for reconsideration of some of the typical design and operation guidelines and criteria, with the goal of exploiting the inherently good thermal performances of gas-fluidized beds at their best. "Creative" and non-conventional design and operation of fluidized beds, like those based on internal and external solids circulation, may be beneficial to the enhancement of thermal diffusivity and surface-to-bed heat transfer, improving the potential for application in the very demanding context of CSP with thermal energy storage. This paper investigated: i) a fluidized bed configuration with an uneven distribution of the fluidizing gas to promote vortices in the scale of bed height (internal solids circulation); ii) a dual fluidized bed configuration characterized by an external solids circulation achieved by the operation of a riser and a bubbling fluidized bed. CFD simulations showed the hydrodynamics conditions under which the internal solids circulation was established. The hydrodynamic characterization of the external solids circulation was achieved by an experimental study carried out with different cold models. The dual fluidized bed system was optimized in terms of operating conditions and geometrical features of the connections between two fluidized beds.

  17. Criterion validity of 3D trunk accelerations to assess external work and power in able-bodied gait.

    Science.gov (United States)

    Meichtry, André; Romkes, Jacqueline; Gobelet, Charles; Brunner, Reinald; Müller, Roland

    2007-01-01

    Evaluative quantification of gait disorder minimizing time-consuming and cost-intensive laboratory installations remains a challenging task in movement analysis. We examined the criterion validity of global gait mechanics assessed by trunk accelerometry. Eight female and four male volunteer subjects (mean age, 27.5 years; S.D., 5.1 years; weight, 68.7+/-11.3kg; height, 1.74+/-0.08m) without gait dysfunction participated in the study. They walked barefoot over two adjacent force-platforms at self-selected speeds. In addition to ground reaction forces, vertical, anterior-posterior and medio-lateral accelerations of the trunk were simultaneously measured by means of a light tri-axial accelerometer. Mean acceleration cycles of the trunk and the body centre of mass were calculated. Acceleration vectors were integrated twice to obtain velocity and displacement vectors of the trunk and the centre of mass, respectively. Temporal boundaries of right and left functional stance phases were defined by the two intermediate moments between maximum anterior-posterior velocity and minimal vertical displacement. Cross-correlations of the kinematics of the trunk and the centre of mass were determined. External work and corresponding symmetry indicators were computed for both methods. Centre of mass anterior-posterior displacement lagged behind the trunk by 3.5% of the gait cycle. External power correlated highly (r>0.82) between the trunk model and the centre of mass. Work correlated moderately high (r=0.77) between the two methods. Work and power asymmetry indexes correlated moderately high (r>0.64). Our findings suggest that accelerometry has the potential to assess functional kinematics and energy-related outcomes in large cohorts.

  18. Operation experience with the LHC RF system

    CERN Document Server

    Arnaudon, L; Brunner, O; Butterworth, A

    2010-01-01

    The LHC ACS RF system is composed of 16 superconducting cavities, eight per ring, housed in a total of four cryomodules each containing four cavities. Each cavity is powered by a 300 kW klystron. The ACS RF power control system is based on industrial Programmable Logic Controllers (PLCs), with additional fast RF interlock protection systems. The Low Level RF (LLRF) is implemented in VME crates. Operational performance and reliability are described. A full set of user interfaces, both for experts and operators has been developed, with user feedback and maintenance issues as key points. Operational experience with the full RF chain, including the low level system, the beam control, the synchronization system and optical fibers distribution is presented. Last but not least overall performance and reliability based on experience with first beam are reviewed and perspectives for future improvement outlined.

  19. RF Loads for Energy Recovery

    CERN Document Server

    Federmann, S; Caspers, F

    2012-01-01

    Different conceptional designs for RF high power loads are presented. One concept implies the use of solid state rectifier modules for direct RF to DC conversion with efficiencies beyond 80%. In addition, robust metallic low-Q resonant structures, capable of operating at high temperatures (>150 ◦C) are discussed. Another design deals with a very high temperature (up to 800 ◦C) air cooled load using a ceramic foam block inside a metal enclosure. This porous ceramic block is the microwave absorber and is not brazed to the metallic enclosure.

  20. Single Feedback Predistortion Linearization Method for RF Power Amplifier%单路反馈射频功放预失真线性化方法

    Institute of Scientific and Technical Information of China (English)

    詹鹏; 秦开宇; 蔡顺燕

    2011-01-01

    该文基于记忆多项式模型,提出一种采用单路反馈的射频功放预失真线性化新方法,只需用正交解调后的IQ信号中的一路,就可完成对预失真器模型参数的获取.该方法可消除使用正交解调器所带来的增益和相位不平衡问题,且节省了一路反馈采样电路,在降低成本、简化设计的同时还能提高预失真线性化的性能.仿真和物理实验结果表明,该文提出的方法是正确的,能达到比较好的线性化效果.%Based on memory polynomial model, this paper proposes a new RF power amplifier predistortion linearization method using single feedback, which only needs the in-phase or quadrature component of the quadrature demodulated IQ signal, and it also can acquire the model parameters of predistorter. This method can eliminate the gain and phase imbalance problems caused by quadrature demodulator, and one feedback sampling circuit is saved, which can reduce the costs, simplify the system design, as well as improve the predistortion linearization performance. Simulation and experiment results show the correctness of the proposed method, which can achieve satisfied linearization performance.

  1. Transversely rf-excited CO/sub 2/ waveguide laser

    Energy Technology Data Exchange (ETDEWEB)

    Lachambre, J.; Macfarlane, J.; Otis, G.; Lavigne, P.

    1978-05-15

    An electrodeless CO/sub 2/ waveguide laser with transverse rf pumping is described. In the rf cw mode, the laser emits up to 0.6 W at 100 Torr. In the rf pulse mode, atmospheric operation has been achieved with pulse duration of 20 ..mu..s and peak power of a few watts at a repetition rate of 300 Hz.

  2. Design of high power radio frequency radial combiner for proton accelerator.

    Science.gov (United States)

    Jain, Akhilesh; Sharma, Deepak Kumar; Gupta, Alok Kumar; Hannurkar, P R

    2009-01-01

    A simplified design method has been proposed for systematic design of novel radio frequency (rf) power combiner and divider, incorporating radial slab-line structure, without using isolation resistor and external tuning mechanism. Due to low insertion loss, high power capability, and rigid mechanical configuration, this structure is advantageous for modern solid state rf power source used for feeding rf energy to superconducting accelerating structures. Analysis, based on equivalent circuit and radial transmission line approximation, provides simple design formula for calculating combiner parameters. Based on this method, novel 8-way and 16-way power combiners, with power handling capability of 4 kW, have been designed, as part of high power solid state rf amplifier development. Detailed experiments showed good performance in accordance with theory.

  3. RF breakdown by toroidal helicons

    Indian Academy of Sciences (India)

    S K P Tripathi; D Bora; M Mishra

    2001-04-01

    Bounded whistlers are well-known for their efficient plasma production capabilities in thin cylindrical tubes. In this paper we shall present their radio frequency (RF) breakdown and discharge sustaining capabilities in toroidal systems. Pulsed RF power in the electronmagnetohydrodynamic (EMHD) frequency regime is fed to the neutral background medium. After the breakdown stage, discharge is sustained by toroidal bounded whistlers. In these pulsed experiments the behaviour of the time evolution of the discharge could be studied in four distinct phases of RF breakdown, steady state attainment, decay and afterglow. In the steady state average electron density of ≈ 1012 per cc and average electron temperature of ≈ 20 eV are obtained at 10-3 mbar of argon filling pressure. Experimental results on toroidal mode structure, background effects and time evolution of the electron distribution function will be presented and their implications in understanding the breakdown mechanism are discussed.

  4. Recycler barrier RF buckets

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, C.M.; /Fermilab

    2011-03-01

    The Recycler Ring at Fermilab uses a barrier rf systems for all of its rf manipulations. In this paper, I will give an overview of historical perspective on barrier rf system, the longitudinal beam dynamics issues, aspects of rf linearization to produce long flat bunches and methods used for emittance measurements of the beam in the RR barrier rf buckets. Current rf manipulation schemes used for antiproton beam stacking and longitudinal momentum mining of the RR beam for the Tevatron collider operation are explained along with their importance in spectacular success of the Tevatron luminosity performance.

  5. Experimental Study on RF Hollow Cathode Discharge

    Institute of Scientific and Technical Information of China (English)

    甘肇强; 吴雪梅; 姚伟国

    2001-01-01

    By using a longitudinal static magnetic field, we have shown that it is possible to excite an intensive plasma in a simple stainless steel tube which is connected with a RF power supply. Under certain conditions, the very bright Ar Ⅱ lines were excited. The emission intensities of Ar Ⅱ lines were increased with the increase in RF power, magnetic field, and the decrease in argon pressure. As the plasma-sheath boundary oscillating under the RF voltage, the plasma column is periodically compressed by the oscillating boundary.``

  6. Development of the RF system for the KOMAC MEBT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seong-Gu; Seol, Kyung-Tae; Kwon, Hyeok-Jung; Kim, Han-Sung; Song, Young-Gi; Cho, Yong-Sub [KOMAC, Gyeongju (Korea, Republic of)

    2015-05-15

    In the 100 MeV proton linear accelerator (Linac) for KOMAC, the RF source will power two-accelerator cavities (an RFQ, a DTL1) operated at a frequency of 350 MHz. The low level RF (LLRF) system for 100 MeV proton linear accelerator provides field control including an RFQ and a DTL at 350 MHz. In our system, an accelerating electric field stability of ±1% in amplitude and ±1° in phase is required for the RF system. Eleven radio-frequency (RF) systems are required for the 100 MeV accelerator, which are one RF system for the radio-frequency quadrupole (RFQ) cavity, one RF system for the 20 MeV drift tube linear accelerator (DTL) tanks, two RF systems for the medium-energy beam transmission (MEBT) tanks, and seven RF systems for the 100 MeV DTL tanks. Now a total of 9 RF systems are being operated. To improve the beam quality, the additional RF system for MEBT (Medium Energy Beam Transport) is needed. An addition of a MEBT RF system will reduce loss of beam quantity caused by gab between 20 MeV DTL tank and 100 MeV DTL tank. RF system for MEBT is being installed. The condition of the test is 350 MHz, 9% pulse duty (1.5 ms, 60 Hz), 4 kW(peak power). Perfecting an RF system of MEBT will reduce loss of beam quantity.

  7. SPS RF System a Tetrode

    CERN Multimedia

    1974-01-01

    The main RF-system of the SPS comprises four cavities: two of 20 m length and two of 16.5 m length. They are all installed in one long straight section (LSS 3). These cavities are of the travelling-wave type operating at a centre frequency of 200.2 MHz. They are wideband, filling time about 700 ns and untuned. The power amplifiers, using tetrodes are installed in a surface building 200 m from the cavities. Initially only two cavities were installed, a third cavity was installed in 1978 and a forth one in 1979. The number of power amplifiers was also gradually increased: by end 1980 there were 8 500 kW units combined in pairs to feed each of the 4 cavities with up to about 1 MW RF power, resulting in a total accelerating voltage of about 8 MV. See also 7412016X, 7412017X, 7411048X.

  8. 手机射频放大器的低功耗研究及改进%Research and Improvement of mobile phone RF Amplifier on Low Power Consumption

    Institute of Scientific and Technical Information of China (English)

    程佳丽

    2012-01-01

      手机的使用越来越广泛,但是手机的待机时间的要求也越来越高。延长待机时间的方法有两种,一是增加电池的容量、二是减少手机的耗电。射频模块的耗电占手机的很大一部分。射频模块低功耗就越来越受大家的关注。本文主要就手机2G 功率放大器的降低功耗提供一个改进方法。%  With mobile phones being used More and more widespread, it required that the standby time of phones should lasted longer and longer. There are two ways to extend the standby time. Firstly, increase the capacity of the battery. And secondly, reduce the power consumption of the mobile phone. The RF module's power consumption accounts for a large part of the mobile phone. So the Low power RF modules are on more and more attention by everyone. The method fol owed would provide an improved method to reduce the power consumption of the power amplifier of the second generation mobile phone.

  9. RF multipole implementation

    CERN Document Server

    Latina, A

    2012-01-01

    The electromagnetic radio-frequency (RF) field of accelerating structures and crab-cavities can exhibit transverse field components due to asymmetries in the azimuthal direction of the element geometry. Tracking simulations must be performed to evaluate the impact of such transverse RF deflections on the beam dynamics. In an ultra-relativistic regime where the Panofsky-Wenzel theorem is applicable, these RF deflections can be modeled via a multipolar expansion of the generating RF field similarly to what is done with static magnetic elements. The element implementing such RF multipolar fields has been called RF multipole. In this note we present an analytical formulation of a thin RF multipole Hamiltonian, and we explicitly calculate the RF kick and the elements of its first- and second- order transfer matrices. Also, we present the implementation of the corresponding code in MAD-X, plus some tests of tracking, simplecticity, consistency, and reflected maps that we successfully applied to verify the correctne...

  10. Clinical application study of externally powered upper-limb prosthetics systems: the VA elbow, the VA hand, and the VA/NU myoelectric hand systems.

    Science.gov (United States)

    Lewis, E A; Sheredos, C R; Sowell, T T; Houston, V L

    1975-01-01

    The results have been presented of a 2-year survey designed to determine whether external power systems offer a significant contribution to the needs of the upper-limb amputee or whether they represent novelties duplicating the functions of conventional mechanical components. The following conclusions have been drawn: 1. External power does offer advantages to the arm amputee. Myoelectric control, especially combined with a self-suspending socket, offers an otherwise normal partial forearm amputee better function without the necessity of a harness. External power, especially for the short partial or total arm amputee and others with limited excursion, brings increased function with less effort. For these patients the advantages of such components as the electric elbow outweigh the recent disadvantages. 2. The components evaluated in this Study are not without limitations. Maintenance requirements of the VA Elbow were excessive. The VA Elbow should not be prescribed for patients who do heavy work with their prostheses because the flexspline may break. Regarding such concerns as lack of sensory feedback, noise, weight, and flexion/extension speed, the advantages of each unit must be weighed against the disadvantages with preference to the individual amputee. 3. The endoskeletal forearm with soft cover is an advantage because of its lightness and cosmesis. 4. Because of the many malfunctions attributed to prosthetist errors, the need is evident for thorough specialized education in the field of external power. A few centralized fabrication facilities may be desirable as opposed to fabrication by many facilities with limited experience. Modular components that are interchangeable and field repairable would be desirable. The systems should be fitted, installed and repaired only by trained prosthetists who have successfully completed a course in externally powered upper-limb prostheses. All members of the Clinic Team should be thoroughly educated in external power as it

  11. Pressurized H2 rf Cavities in Ionizing Beams and Magnetic Fields

    Energy Technology Data Exchange (ETDEWEB)

    Chung, M.; Collura, M. G.; Flanagan, G.; Freemire, B.; Hanlet, P. M.; Jana, M. R.; Johnson, R. P.; Kaplan, D. M.; Leonova, M.; Moretti, A.; Popovic, M.; Schwarz, T.; Tollestrup, A.; Torun, Y.; Yonehara, K.

    2013-10-01

    A major technological challenge in building a muon cooling channel is operating RF cavities in multi-tesla external magnetic fields. We report the first experimental characterization of a high pressure gas-filled 805 MHz RF cavity for use with intense ionizing beams and strong external magnetic fields. RF power consumption by beam-induced plasma was investigated with hydrogen and deuterium gases with pressures between 20 and 100 atm and peak RF gradients between 5 and 50 MV/m. The energy absorption per ion pair-RF cycle ranges from 10-18 to 10-16 J. The low pressure case agrees well with an analytical model based on electron and ion mobilities. Varying concentrations of oxygen gas were investigated to remove free electrons from the cavity and reduce the RF power consumption. Measurements of the electron attachment time to oxygen and rate of ion-ion recombination were also made. Additionally, we demonstrate the operation of the gas-filled RF cavity in a solenoidal field of up to 3 T, finding no major magnetic field dependence. These results indicate that a high pressure gas-filled cavity is potentially a viable technology for muon ionization cooling.

  12. Langmuir probe studies on a RF ion source for NBI

    Energy Technology Data Exchange (ETDEWEB)

    McNeely, P. E-mail: p.mcneely@ipp.mpg.de; Heineman, B.; Kraus, W.; Riedl, R.; Speth, E.; Vollmer, O

    2001-10-01

    IPP Garching has been developing a RF ion source for H{sup -} production. In order to improve the data quality a new scanning probe system with passive RF compensation has been installed on the Type VI ion source on the BATMAN test stand. Using this probe, measurements have been carried out to study changes to the plasma parameters (electron density, electron temperature, and plasma potential) due to variation in the source operating conditions. The data were collected at a source pressure of 0.5 Pa and with 60{+-}5 kW applied RF power. Presented are some of the results of these measurements, focusing on the effect of: argon seeding, addition of Cs to the source, and the newly added Faraday screen. The electron density behaves in a fashion that agrees with the theory of ambipolar diffusion. Typically there is little change to the average electron energy observed regardless of which effect is considered. The plasma potential shows the most significant changes with external source conditions, both in value for all cases and shape when the Faraday screen was added.

  13. A large-area RF source for negative hydrogen ions

    Science.gov (United States)

    Frank, P.; Feist, J. H.; Kraus, W.; Speth, E.; Heinemann, B.; Probst, F.; Trainham, R.; Jacquot, C.

    1998-08-01

    In a collaboration with CEA Cadarache, IPP is presently developing an rf source, in which the production of negative ions (H-/D-) is being investigated. It utilizes PINI-size rf sources with an external antenna and for the first step a small size extraction system with 48 cm2 net extraction area. First results from BATMAN (Ba¯varian T_est Ma¯chine for N_egative Ions) show (without Cs) a linear dependence of the negative ion yield with rf power, without any sign of saturation. At elevated pressure (1.6 Pa) a current density of 4.5 mA/cm2 H- (without Cs) has been found so far. At medium pressure (0.6 Pa) the current density is lower by approx. a factor of 5, but preliminary results with Cesium injection show a relative increase by almost the same factor in this pressure range. Langmuir probe measurements indicate an electron temperature Te>2 eV close to the plasma grid with a moderate magnetic filter (700 Gcm). Attempts to improve the performance by using different magnetic configurations and different wall materials are under way.

  14. RF Transceiver Design for MIMO Wireless Communications

    CERN Document Server

    Mohammadi, Abbas

    2012-01-01

    This practical resource offers a thorough examination of RF transceiver design for MIMO communications.  Offering a practical view on MIMO wireless systems, this book extends fundamental concepts on classic wireless transceiver design techniques to MIMO transceivers. This helps reader gain a very comprehensive understanding of the subject. This in-depth volume describes many theoretical and implementation challenges on MIMO transceivers and provides the practical solutions for these issues. This comprehensive book provides thorough descriptions of MIMO theoretical concepts, MIMO single carrier and OFDM modulation, RF transceiver design concepts, power amplifier, MIMO transmitter design techniques and their RF impairments, MIMO receiver design methods, RF impairments study including nonlinearity, DC-offset, I/Q imbalance and phase noise and their compensation in OFDM and MIMO techniques. In addition, it provides the most practical techniques to realize RF front-ends in MIMO systems. This book is supported wit...

  15. RF pulse compression for future linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, P.B.

    1995-05-01

    Future (nonsuperconducting) linear colliders will require very high values of peak rf power per meter of accelerating structure. The role of rf pulse compression in producing this power is examined within the context of overall rf system design for three future colliders at energies of 1.0--1.5 TeV, 5 TeV and 25 TeV. In order keep the average AC input power and the length of the accelerator within reasonable limits, a collider in the 1.0--1.5 TeV energy range will probably be built at an x-band rf frequency, and will require a peak power on the order of 150--200 MW per meter of accelerating structure. A 5 TeV collider at 34 GHz with a reasonable length (35 km) and AC input power (225 MW) would require about 550 MW per meter of structure. Two-beam accelerators can achieve peak powers of this order by applying dc pulse compression techniques (induction linac modules) to produce the drive beam. Klystron-driven colliders achieve high peak power by a combination of dc pulse compression (modulators) and rf pulse compression, with about the same overall rf system efficiency (30--40%) as a two-beam collider. A high gain (6.8) three-stage binary pulse compression system with high efficiency (80%) is described, which (compared to a SLED-11 system) can be used to reduce the klystron peak power by about a factor of two, or alternately, to cut the number of klystrons in half for a 1.0--1.5 TeV x-band collider. For a 5 TeV klystron-driven collider, a high gain, high efficiency rf pulse compression system is essential.

  16. Comparison of childhood thyroid cancer prevalence among 3 areas based on external radiation dose after the Fukushima Daiichi nuclear power plant accident: The Fukushima health management survey.

    Science.gov (United States)

    Ohira, Tetsuya; Takahashi, Hideto; Yasumura, Seiji; Ohtsuru, Akira; Midorikawa, Sanae; Suzuki, Satoru; Fukushima, Toshihiko; Shimura, Hiroki; Ishikawa, Tetsuo; Sakai, Akira; Yamashita, Shunichi; Tanigawa, Koichi; Ohto, Hitoshi; Abe, Masafumi; Suzuki, Shinichi

    2016-08-01

    The 2011 Great East Japan Earthquake led to a subsequent nuclear accident at the Fukushima Daiichi Nuclear Power Plant. In its wake, we sought to examine the association between external radiation dose and thyroid cancer in Fukushima Prefecture. We applied a cross-sectional study design with 300,476 participants aged 18 years and younger who underwent thyroid examinations between October 2011 and June 2015. Areas within Fukushima Prefecture were divided into three groups based on individual external doses (≥1% of 5 mSv, accident and thyroid examination was not associated with thyroid cancer prevalence. There were no significant associations between individual external doses and prevalence of thyroid cancer. External radiation dose was not associated with thyroid cancer prevalence among Fukushima children within the first 4 years after the nuclear accident.

  17. "Virtual IED sensor" at an rf-biased electrode in low-pressure plasma

    Science.gov (United States)

    Bogdanova, M. A.; Lopaev, D. V.; Zyryanov, S. M.; Rakhimov, A. T.

    2016-07-01

    Energy distribution and the flux of the ions coming on a surface are considered as the key-parameters in anisotropic plasma etching. Since direct ion energy distribution (IED) measurements at the treated surface during plasma processing are often hardly possible, there is an opportunity for virtual ones. This work is devoted to the possibility of such indirect IED and ion flux measurements at an rf-biased electrode in low-pressure rf plasma by using a "virtual IED sensor" which represents "in-situ" IED calculations on the absolute scale in accordance with a plasma sheath model containing a set of measurable external parameters. The "virtual IED sensor" should also involve some external calibration procedure. Applicability and accuracy of the "virtual IED sensor" are validated for a dual-frequency reactive ion etching (RIE) inductively coupled plasma (ICP) reactor with a capacitively coupled rf-biased electrode. The validation is carried out for heavy (Ar) and light (H2) gases under different discharge conditions (different ICP powers, rf-bias frequencies, and voltages). An EQP mass-spectrometer and an rf-compensated Langmuir probe (LP) are used to characterize plasma, while an rf-compensated retarded field energy analyzer (RFEA) is applied to measure IED and ion flux at the rf-biased electrode. Besides, the pulsed selfbias method is used as an external calibration procedure for ion flux estimating at the rf-biased electrode. It is shown that pulsed selfbias method allows calibrating the IED absolute scale quite accurately. It is also shown that the "virtual IED sensor" based on the simplest collisionless sheath model allows reproducing well enough the experimental IEDs at the pressures when the sheath thickness s is less than the ion mean free path λi (s λi), the difference between calculated and experimental IEDs due to ion collisions in the sheath is observed in the low energy range. The effect of electron impact ionization in the sheath on the origin and

  18. Dual-wavelength high-power diode laser system based on an external-cavity tapered amplifier with tunable frequency difference

    DEFF Research Database (Denmark)

    Chi, Mingjun; Jensen, Ole Bjarlin; Petersen, Paul Michael

    2012-01-01

    A dual-wavelength high-power semiconductor laser system based on a tapered amplifier with double-Littrow external cavity is demonstrated around 800 nm. The two wavelengths can be tuned individually, and the frequency difference of the two wavelengths is tunable from 0.5 to 10.0 THz. To our knowle...

  19. Effects of Small-Sided Soccer Games on Internal and External Load and Lower Limb Power: A Pilot Study in Collegiate Players

    Directory of Open Access Journals (Sweden)

    Clemente Filipe Manuel

    2017-03-01

    Full Text Available Purpose. The aim of the study was to examine the influence of small-sided and conditioned games (SSG on the internal load (heart rate [HR] and perceived exertion, external load (Global Positioning System variables, and lower limb power (squat jump [SJ] and countermovement jump [CMJ].

  20. A YBCO RF-SQUID magnetometer and its applications

    Science.gov (United States)

    Luwei, Zhou; Jingwu, Qiu; Xienfeng, Zhang; Zhiming, Tank; Yongjia, Qian

    1990-01-01

    An applicable RF-superconducting quantum interference detector (SQUID) magnetometer was made using a bulk sintered yttrium barium copper oxide (YBCO). The temperature range of the magnetometer is 77 to 300 K and the field range 0 to 0.1T. At 77 K, the equivalent flux noise of the SQUID is 5 x 10 to minus 4 power theta sub o/square root of Hz at the frequency range of 20 to 200 Hz. The experiments show that the SQUID noise at low-frequency end is mainly from 1/f noise. A coil test shows that the magnetic moment sensitivity delta m is 10 to the minus 6th power emu. The RF-SQUID is shielded in a YBCO cylinder with a shielding ability B sub in/B sub ex of about 10 to the minus 6th power when external dc magnetic field is about a few Oe. The magnetometer is successfully used in characterizing superconducting thin films.

  1. Matching network for RF plasma source

    Science.gov (United States)

    Pickard, Daniel S.; Leung, Ka-Ngo

    2007-11-20

    A compact matching network couples an RF power supply to an RF antenna in a plasma generator. The simple and compact impedance matching network matches the plasma load to the impedance of a coaxial transmission line and the output impedance of an RF amplifier at radio frequencies. The matching network is formed of a resonantly tuned circuit formed of a variable capacitor and an inductor in a series resonance configuration, and a ferrite core transformer coupled to the resonantly tuned circuit. This matching network is compact enough to fit in existing compact focused ion beam systems.

  2. Si-based RF MEMS components.

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, James E.; Nordquist, Christopher Daniel; Baker, Michael Sean; Fleming, James Grant; Stewart, Harold D.; Dyck, Christopher William

    2005-01-01

    Radio frequency microelectromechanical systems (RF MEMS) are an enabling technology for next-generation communications and radar systems in both military and commercial sectors. RF MEMS-based reconfigurable circuits outperform solid-state circuits in terms of insertion loss, linearity, and static power consumption and are advantageous in applications where high signal power and nanosecond switching speeds are not required. We have demonstrated a number of RF MEMS switches on high-resistivity silicon (high-R Si) that were fabricated by leveraging the volume manufacturing processes available in the Microelectronics Development Laboratory (MDL), a Class-1, radiation-hardened CMOS manufacturing facility. We describe novel tungsten and aluminum-based processes, and present results of switches developed in each of these processes. Series and shunt ohmic switches and shunt capacitive switches were successfully demonstrated. The implications of fabricating on high-R Si and suggested future directions for developing low-loss RF MEMS-based circuits are also discussed.

  3. The LHC Low Level RF

    CERN Document Server

    Baudrenghien, Philippe; Molendijk, John Cornelis; Olsen, Ragnar; Rohlev, Anton; Rossi, Vittorio; Stellfeld, Donat; Valuch, Daniel; Wehrle, Urs

    2006-01-01

    The LHC RF consists of eight 400 MHz superconducting cavities per ring, with each cavity independently powered by a 300 kW klystron, via a circulator. The challenge for the Low Level is to cope with very high beam current (more than 1 A RF component) and achieve excellent beam lifetime (emittance growth time in excess of 25 hours). Each cavity has an associated Cavity Controller rack consisting of two VME crates which implement high gain RF Feedback, a Tuner Loop with a new algorithm, a Klystron Ripple Loop and a Conditioning system. In addition each ring has a Beam Control system (four VME crates) which includes a Frequency Program, Phase Loop, Radial Loop and Synchronization Loop. A Longitudinal Damper (dipole and quadrupole mode) acting via the 400 MHz cavities is included to reduce emittance blow-up due to filamentation from phase and energy errors at injection. Finally an RF Synchronization system implements the bunch into bucket transfer from the SPS into each LHC ring. When fully installed in 2007, the...

  4. Method of electron emission control in RF guns

    CERN Document Server

    Khodak, I V

    2001-01-01

    The electron emission control method for a RF gun is considered.According to the main idea of the method,the additional resonance system is created in a cathode region where the RF field strength could be varied using the external pulse equipment. The additional resonance system is composed of a coaxial cavity coupled with a RF gun cylindrical cavity via an axial hole. Computed results of radiofrequency and electrodynamic performances of such a two-cavity system and results of the RF gun model pilot study are presented in. Results of particle dynamics simulation are described.

  5. Microstructures using RF sputtered PSG film as a sacrificial layer in surface micromachining

    Indian Academy of Sciences (India)

    Vivekanand Bhatt; Sudhir Chandra; Chatar Singh

    2009-08-01

    In this paper, we explore RF magnetron sputtered Phosphor–silicate–glass (PSG) film as a sacrificial layer in surface micromachining technology. For this purpose, a 76 mm diameter target of phosphorus-doped silicon dioxide was prepared by conventional solid-state reaction route using P25 and SiO2 powders. The PSG films were prepared in a RF (13·56 MHz) magnetron sputtering system at 300 watt RF power, 20 mTorr pressure and 45 mm target-to-substrate spacing without external substrate heating. Microstructures of sputtered silicon dioxide film were fabricated using sputtered PSG film as sacrificial layer in surface micromachining process.

  6. RF study and 3-D simulations of a side-coupling thermionic RF-gun

    Science.gov (United States)

    Rimjaem, S.; Kusoljariyakul, K.; Thongbai, C.

    2014-02-01

    A thermionic RF-gun for generating ultra-short electron bunches was optimized, developed and used as a source at a linac-based THz radiation research laboratory of the Plasma and Beam Physics Research Facility, Chiang Mai University, Thailand. The RF-gun is a π/2-mode standing wave structure, which consists of two S-band accelerating cells and a side-coupling cavity. The 2856 MHz RF wave is supplied from an S-band klystron to the gun through the waveguide input-port at the cylindrical wall of the second cell. A fraction of the RF power is coupled from the second cell to the first one via a side-coupling cavity. Both the waveguide input-port and the side-coupling cavity lead to an asymmetric geometry of the gun. RF properties and electromagnetic field distributions inside the RF-gun were studied and numerically simulated by using computer codes SUPERFISH 7.19 and CST Microwave Studio 2012©. RF characterizations and tunings of the RF-gun were performed to ensure the reliability of the gun operation. The results from 3D simulations and measurements are compared and discussed in this paper. The influence of asymmetric field distributions inside the RF-gun on the electron beam properties was investigated via 3D beam dynamics simulations. A change in the coupling-plane of the side-coupling cavity is suggested to improve the gun performance.

  7. RF study and 3-D simulations of a side-coupling thermionic RF-gun

    Energy Technology Data Exchange (ETDEWEB)

    Rimjaem, S., E-mail: sakhorn.rimjaem@cmu.ac.th [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics (ThEP), Commission on Higher Education, Bangkok 10400 (Thailand); Kusoljariyakul, K.; Thongbai, C. [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics (ThEP), Commission on Higher Education, Bangkok 10400 (Thailand)

    2014-02-01

    A thermionic RF-gun for generating ultra-short electron bunches was optimized, developed and used as a source at a linac-based THz radiation research laboratory of the Plasma and Beam Physics Research Facility, Chiang Mai University, Thailand. The RF-gun is a π/2-mode standing wave structure, which consists of two S-band accelerating cells and a side-coupling cavity. The 2856 MHz RF wave is supplied from an S-band klystron to the gun through the waveguide input-port at the cylindrical wall of the second cell. A fraction of the RF power is coupled from the second cell to the first one via a side-coupling cavity. Both the waveguide input-port and the side-coupling cavity lead to an asymmetric geometry of the gun. RF properties and electromagnetic field distributions inside the RF-gun were studied and numerically simulated by using computer codes SUPERFISH 7.19 and CST Microwave Studio 2012{sup ©}. RF characterizations and tunings of the RF-gun were performed to ensure the reliability of the gun operation. The results from 3D simulations and measurements are compared and discussed in this paper. The influence of asymmetric field distributions inside the RF-gun on the electron beam properties was investigated via 3D beam dynamics simulations. A change in the coupling-plane of the side-coupling cavity is suggested to improve the gun performance.

  8. Environmental externalities: An ASEAN application to coal-based power generation. [Association of South East Asian Nations (ASEAN)

    Energy Technology Data Exchange (ETDEWEB)

    Szpunar, C.B.; Gillette, J.L.

    1992-06-01

    Significant benefits to human health that result from emissions control programs may justify the costs of pollution control policies. Many scientists, economists, risk analysts, and policymakers believe that comparisons of the benefits with the costs of pollution control demonstrate that the US stationary source, air emissions control program is justified. This justification is based upon pronounced benefits to human health, especially from controlling suspended particulates and sulfur compounds. Market decisions are usually made on the basis of a consideration of traditional costs such as capital, operating and maintenance, fuel costs, and fixed charges. Social costs, which could be significant, are not incorporated explicitly into such decisions. These social costs could result in a net reduction in the welfare of individuals, and of society as a whole. Because these social costs and their effects are not represented in the price of energy, individual have no way to explicitly value them; hence, they remain unaccounted for in market decisions. By accounting for external costs, the selection of energy sources and production of energy products can lead to and equilibrium, where the total cost of energy and energy products, together with resulting social costs, can be brought to an economic minimum. The concept of an air emissions control program is of interest to the ASEAN countries (Brunei, Indonesia, Malaysia, the Philippines, Singapore, and Thailand) and their governments, especially if such a program could be justified in cost-benefit terms and shown to be directly applicable to ASEAN conditions. It is the intent of the effort described herein to demonstrate that technical options are available to control emissions from coal-based, electric power plants and that that costs of these options may be justified in cost-benefit terms.

  9. Estimation of the external cost of energy production based on fossil fuels in Finland and a comparison with estimates of external costs of wind power

    Energy Technology Data Exchange (ETDEWEB)

    Otterstroem, T. [Ekono Energy Ltd, Helsinki (Finland)

    1995-12-31

    Ekono Energy Ltd. and Soil and Water Ltd. participated in 1993 - 1994 in the SIHTI 2 research programme of the Ministry of Trade and Industry by carrying out the project `Estimation of the extremal cost of energy production in Finland`. The aim of the survey was to assess the external costs of Finnish energy production which are incurred by the environmental impacts of emissions during the life cycles of fossil fuels. To this end, the survey studied the environmental impacts of emissions on a local level (population centres), on a national level (Finland) and on a global level. The main target was to develop a method for calculating the economic value of these impacts. The method was applied to the emissions in 1990. During the survey, the main emphasis was put on developing and applying indirect valuation methods. An indirect method proceeds through dose-response functions. The dose-response function links a certain emission quantity, concentration or deposition to the extent or intensity of the effect. When quantitative data on hazards is available, it is possible to carry out monetary valuation by means of market prices or people`s otherwise expressed willingness to pay (WTP). Monetary valuation includes many uncertainty factors, of which the most significant with regard to this study are the transferability of dose-response functions and willingness-to-pay values from different kinds of conditions, additivity of damage values, uncertainty factors and problems related to discounting

  10. Binary rf pulse compression experiment at SLAC

    Energy Technology Data Exchange (ETDEWEB)

    Lavine, T.L.; Spalek, G.; Farkas, Z.D.; Menegat, A.; Miller, R.H.; Nantista, C.; Wilson, P.B.

    1990-06-01

    Using rf pulse compression it will be possible to boost the 50- to 100-MW output expected from high-power microwave tubes operating in the 10- to 20-GHz frequency range, to the 300- to 1000-MW level required by the next generation of high-gradient linacs for linear for linear colliders. A high-power X-band three-stage binary rf pulse compressor has been implemented and operated at the Stanford Linear Accelerator Center (SLAC). In each of three successive stages, the rf pulse-length is compressed by half, and the peak power is approximately doubled. The experimental results presented here have been obtained at low-power (1-kW) and high-power (15-MW) input levels in initial testing with a TWT and a klystron. Rf pulses initially 770 nsec long have been compressed to 60 nsec. Peak power gains of 1.8 per stage, and 5.5 for three stages, have been measured. This corresponds to a peak power compression efficiency of about 90% per stage, or about 70% for three stages, consistent with the individual component losses. The principle of operation of a binary pulse compressor (BPC) is described in detail elsewhere. We recently have implemented and operated at SLAC a high-power (high-vacuum) three-stage X-band BPC. First results from the high-power three-stage BPC experiment are reported here.

  11. Investigation of RF Signal Energy Harvesting

    Directory of Open Access Journals (Sweden)

    Soudeh Heydari Nasab

    2010-01-01

    Full Text Available The potential utilization of RF signals for DC power is experimentally investigated. The aim of the work is to investigate the levels of power that can be harvested from the air and processed to achieve levels of energy that are sufficient to charge up low-power electronic circuits. The work presented shows field measurements from two selected regions: an urbanized hence signal congested area and a less populated one. An RF harvesting system has been specifically designed, built, and shown to successfully pick up enough energy to power up circuits. The work concludes that while RF harvesting was successful under certain conditions, however, it required the support of other energy harvesting techniques to replace a battery. Efficiency considerations have, hence, placed emphasis on comparing the developed harvester to other systems.

  12. RF feedback for KEKB

    Energy Technology Data Exchange (ETDEWEB)

    Ezura, Eizi; Yoshimoto, Shin-ichi; Akai, Kazunori [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

    1996-08-01

    This paper describes the present status of the RF feedback development for the KEK B-Factory (KEKB). A preliminary experiment concerning the RF feedback using a parallel comb-filter was performed through a choke-mode cavity and a klystron. The RF feedback has been tested using the beam of the TRISTAN Main Ring, and has proved to be effective in damping the beam instability. (author)

  13. 5 MW 805 MHz SNS RF System Experience

    CERN Document Server

    Young, Karen A; Hardek, Thomas; Lynch, Michael; Rees, Daniel; Roybal, William; Tallerico, Paul J; Thomas Bradley, Joseph

    2005-01-01

    The RF system for the 805 MHz normal conducting linac of the Spallation Nuetron Source (SNS) accelerator was designed, procured and tested at Los Alamos National Laboratory(LANL) and then installed and commissioned at Oak Ridge National Laboratory (ORNL). The RF power for this room temperature coupled cavity linac (CCL) of SNS accelerator is generated by four pulsed 5 MW peak power klystrons operating with a pulse width of 1.25 mSec and a 60 Hz repetition frequency. The RF power from each klystron is divided and delivered to the CCL through two separate RF windows. The 5 MW RF system advanced the state of the art for simultaneous peak and average power. This paper summarizes the problems encountered, lessons learned and results of the high power testing at LANL of the 5 MW klystrons, 5 MW circulators, 5 MW loads, and 2.5 MW windows.*

  14. Superconductor Digital-RF Transceiver Components

    Science.gov (United States)

    2006-01-01

    high-power amplifier (HPA). The diagram also shows a dynamic digital equalizer, a digital predistortion module that is combined with the DAC to...intermodulation distortion, especially near their maximum output powers. Unlike conventional baseband or intermediate frequency (IF) predistorters ...which are limited to narrowband correction of slowly varying non- linearities, our RF predistorter can correct instantaneous, signal-dependent

  15. A Micromechanical RF Channelizer

    Science.gov (United States)

    Akgul, Mehmet

    The power consumption of a radio generally goes as the number and strength of the RF signals it must process. In particular, a radio receiver would consume much less power if the signal presented to its electronics contained only the desired signal in a tiny percent bandwidth frequency channel, rather than the typical mix of signals containing unwanted energy outside the desired channel. Unfortunately, a lack of filters capable of selecting single channel bandwidths at RF forces the front-ends of contemporary receivers to accept unwanted signals, and thus, to operate with sub-optimal efficiency. This dissertation focuses on the degree to which capacitive-gap transduced micromechanical resonators can achieve the aforementioned RF channel-selecting filters. It aims to first show theoretically that with appropriate scaling capacitive-gap transducers are strong enough to meet the needed coupling requirements; and second, to fully detail an architecture and design procedure needed to realize said filters. Finally, this dissertation provides an actual experimentally demonstrated RF channel-select filter designed using the developed procedures and confirming theoretical predictions. Specifically, this dissertation introduces four methods that make possible the design and fabrication of RF channel-select filters. The first of these introduces a small-signal equivalent circuit for parallel-plate capacitive-gap transduced micromechanical resonators that employs negative capacitance to model the dependence of resonance frequency on electrical stiffness in a way that facilitates the analysis of micromechanical circuits loaded with arbitrary electrical impedances. The new circuit model not only correctly predicts the dependence of electrical stiffness on the impedances loading the input and output electrodes of parallel-plate capacitive-gap transduced micromechanical device, but does so in a visually intuitive way that identifies current drive as most appropriate for

  16. Development of a dual-pulse RF driver for an S-band (= 2856 MHz) RF electron linear accelerator

    Science.gov (United States)

    Cha, Sungsu; Kim, Yujong; Lee, Byeong-No; Lee, Byung Cheol; Cha, Hyungki; Ha, Jang Ho; Park, Hyung Dal; Lee, Seung Hyun; Kim, Hui Su; Buaphad, Pikad

    2016-04-01

    The radiation equipment research division of Korea Atomic Energy Research Institute has developed a Container Inspection System (CIS) using a Radio Frequency (RF) electron linear accelerator for port security. The primary purpose of the CIS is to detect nuclear materials and explosives, as well country-specific prohibited substances, e.g., smuggled. The CIS consists of a 9/6 MeV dualenergy electron linear accelerator for distinguishing between organic and inorganic materials. The accelerator consists of an electron gun, an RF accelerating structure, an RF driver, a modulator, electromagnets, a cooling system, a X-ray generating target, X-ray collimator, a detector, and a container moving system. The RF driver is an important part of the configuration because it is the RF power source: it supplies the RF power to the accelerating structure. A unique aspect of the RF driver is that it generates dual RF power to generate dual energy (9/6 MeV). The advantage of this RF driver is that it can allow the pulse width to vary and can be used to obtain a wide range of energy output, and pulse repetition rates up to 300 Hz. For this reason, 140 W (5 MW - 9 MeV) and 37 W (3.4 MW - 6 MeV) power outputs are available independently. A high power test for 20 minutes demonstrate that stable dual output powers can be generated. Moreover, the dual power can be applied to the accelerator which has stable accelerator operation. In this paper, the design, fabrication and high power test of the RF driver for the RF electron linear accelerator (linac) are presented.

  17. Fundamental Study of a Combined Hyperthermia System with RF Capacitive Heating and Interstitial Heating

    OpenAIRE

    Saitoh, Yoshiaki; Hori, Junichi; 斉藤, 義明; 堀, 潤一

    2001-01-01

    Interstitial RF heating with an inserted electrode allows the heating position selection in a subject, but the narrow heating region is problematic. This study elucidates development of new interstitial RF heating methods, combining with external RF heating using paired electrodes, heating the subject broadly in advance in order to selectively extend the heating region. Two kinds of heating system were developed by controlling a differential mode and a common mode of RF currents. Heating expe...

  18. Fundamental Study of a Combined Hyperthermia System with RF Capacitive Heating and Interstitial Heating

    OpenAIRE

    Saitoh, Yoshiaki; Hori, Junichi; 斉藤, 義明; 堀, 潤一

    2001-01-01

    Interstitial RF heating with an inserted electrode allows the heating position selection in a subject, but the narrow heating region is problematic. This study elucidates development of new interstitial RF heating methods, combining with external RF heating using paired electrodes, heating the subject broadly in advance in order to selectively extend the heating region. Two kinds of heating system were developed by controlling a differential mode and a common mode of RF currents. Heating expe...

  19. RF design and tests on a broadband, high-power coaxial quadrature hybrid applicable to ITER ICRF transmission line system for load-resilient operations

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hae Jin, E-mail: haejin@nfri.re.kr [National Fusion Research Institute, Daejeon (Korea, Republic of); Wang, Son Jong; Park, Byoung Ho; Kwak, Jong-Gu [National Fusion Research Institute, Daejeon (Korea, Republic of); Hillairet, Julien [CEA/IRFM, Saint-lez-Durance (France); Choi, Jin Joo [Kwangwoon University, Seoul (Korea, Republic of)

    2015-10-15

    Highlights: • Amplitude balanced 3 dB coaxial hybrid splitter has been designed and rf tested. • The proposed hybrid is applicable to ITER ICRF transmission line for load resilience. • Two-section, broadband coaxial hybrid can be tunable by changing dielectric insulator. - Abstract: RF design and network analyzer tests of broadband, amplitude-balanced coaxial hybrid junctions are presented. We have designed two 3 dB hybrid splitters with 9 and 12 in. coaxial transmission lines applicable to ITER ICRF for load-resilient operations using ANSYS HFSS. Amplitude-balanced broadband responses were obtained with the combination of impedance reductions of longitudinal and transverse branches in unequal proportion, length change of 50 Ω lines and diameter change of high impedance lines connected transversely to the T-section of the hybrid splitter, respectively. We have fabricated and RF tested the 9 in. coaxial hybrid coupler. We obtained an excellent coupling flatness of −3.2 ± 0.2 dB, phase difference of 4 degrees and return loss of 16 dB in 40–55 MHz. The measured data of 9 in. hybrid splitter is highly consistent with HFSS simulations. We found that the proposed 3 dB hybrid splitter can be tunable with amplitude-balanced, broadband response by changing dielectric insulators to keep the inner and outer conductors of coaxial line apart. The proposed 3 dB hybrid splitter can be utilized for load-resilient operations in a wide range of antenna load variations due to mode transitions or edge localized modes (ELMs) in fusion plasmas.

  20. FERMILAB CRYOMODULE TEST STAND RF INTERLOCK SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, Troy [Fermilab; Diamond, J. S. [Fermilab; McDowell, D. [Fermilab; Nicklaus, D. [Fermilab; Prieto, P. S. [Fermilab; Semenov, A. [Fermilab

    2016-10-12

    An interlock system has been designed for the Fermilab Cryo-module Test Stand (CMTS), a test bed for the cryo- modules to be used in the upcoming Linac Coherent Light Source 2 (LCLS-II) project at SLAC. The interlock system features 8 independent subsystems, one per superconducting RF cavity and solid state amplifier (SSA) pair. Each system monitors several devices to detect fault conditions such as arcing in the waveguides or quenching of the SRF system. Additionally each system can detect fault conditions by monitoring the RF power seen at the cavity coupler through a directional coupler. In the event of a fault condition, each system is capable of removing RF signal to the amplifier (via a fast RF switch) as well as turning off the SSA. Additionally, each input signal is available for re- mote viewing and recording via a Fermilab designed digitizer board and MVME 5500 processor.

  1. Characterization of Energy Availability in RF Energy Harvesting Networks

    Directory of Open Access Journals (Sweden)

    Daniela Oliveira

    2016-01-01

    Full Text Available The multiple nodes forming a Radio Frequency (RF Energy Harvesting Network (RF-EHN have the capability of converting received electromagnetic RF signals in energy that can be used to power a network device (the energy harvester. Traditionally the RF signals are provided by high power transmitters (e.g., base stations operating in the neighborhood of the harvesters. Admitting that the transmitters are spatially distributed according to a spatial Poisson process, we start by characterizing the distribution of the RF power received by an energy harvester node. Considering Gamma shadowing and Rayleigh fading, we show that the received RF power can be approximated by the sum of multiple Gamma distributions with different scale and shape parameters. Using the distribution of the received RF power, we derive the probability of a node having enough energy to transmit a packet after a given amount of charging time. The RF power distribution and the probability of a harvester having enough energy to transmit a packet are validated through simulation. The numerical results obtained with the proposed analysis are close to the ones obtained through simulation, which confirms the accuracy of the proposed analysis.

  2. Low power RF/analog f ront-end solution for UHF RFID%低功耗UHF RFID射频/模拟前端解决方案

    Institute of Scientific and Technical Information of China (English)

    杜永乾; 庄奕琪; 李小明; 刘伟峰

    2014-01-01

    A RF/analog front-end for passive UHF RFID was presented .The system power consump-tion was optimized by time-divided and domain-divide power supply .The overall circuits included volt-age multiplier ,three voltage regulators ,power-on-reset ,ring oscillator ,voltage reference ,modulator and demodulator ,where the power efficiency voltage multiplier was improved through threshold volt-age compensation ,and the power efficiency was not smaller than 48% ;the low power current-sum-ming voltage reference had both high accuracy and small chip size ;the amplitude shift keying (ASK) demodulator without huge passive devices solved the error-detection and distortion problem through system level .The RF/analog front-end was designed and implemented in SMIC 0 .18 μm CMOS tech-nology .Test results show that the total direct current (DC) power consumption is 3 .6μA .The active area of the RF/analog front-end is about 0 .27 mm2 .The RF/analog front-end was finally integrated into a full UHF RFID chip ,and tested by a commercial reader .The reading distance is larger than 6 m ,and the read speed of the RFID chip reaches 89 .9/s .%提出了用于无源超高频射频识别(UHF RFID)芯片的射频/模拟前端.该射频/模拟前端通过系统分区和分时供电优化了系统功耗,子电路包括整流电路、基准电路、三轨稳压电路、解调/调制电路、上电复位电路以及时钟电路.通过引入阈值补偿,将全CMOS整流电路的整流效率提升至不低于48%;电流求和型亚阈值基准电路在保证基准精度的同时,有效降低了功耗和芯片面积;无需大尺寸无源器件的解调电路,并从系统架构层面解决了解调失真的问题.该射频/模拟前端电路采用SMIC0.18μmCMOS工艺库仿真并投片验证,测试结果表明:直流功耗为3.6μA,芯片有效面积为0.27mm2.将该射频/模拟前端电路集成至一款UHFRFID标签芯片中,采用商用阅读器进

  3. Accelerating Rf System Of Microtron-recuperator For Fel

    CERN Document Server

    Arbuzov, V S; Gorniker, E I; Kendjebulatov, E K; Kolobanov, E I; Kondakov, A A; Krutikhin, S A; Kuptsov, I V; Kurkin, G Ya; Medvedev, L E; Motygin, S V; Osipov, V N; Petrov, V M; Pilan, Andrey M; Popov, A M; Sedlyarov, I K; Tribendis, A G

    2004-01-01

    FEL (Free Electron Laser) for the Siberian Centre of Photochemical Research is constructed in Novosibirsk. Parameters and last results received on a RF system of the race-track microtron-recuperator for FEL are given in the report. The frequency of the RF system is 180.4 MHz. The RF system operates in continuous mode. The 16 cavities are used in accelerating system of the microtron-recuperator. The RF system is consists of two channels. Each of two 600kW generators drives 8 cavities. Each channel was tested at 7500 kV on the gaps of 8 cavities. The RF power was 630 kW per channel. Now, the accelerating RF system operates at 13600 kV on 16 cavities. Total power of generators is 1100kW.

  4. Single-pass UV generation at 222.5 nm based on high-power GaN external cavity diode laser.

    Science.gov (United States)

    Ruhnke, N; Müller, A; Eppich, B; Güther, R; Maiwald, M; Sumpf, B; Erbert, G; Tränkle, G

    2015-05-01

    We demonstrate a compact system for single-pass frequency doubling of high-power GaN diode laser radiation. The deep UV laser light at 222.5 nm is generated in a β-BaB2O4 (BBO) crystal. A high-power GaN external cavity diode laser (ECDL) system in Littrow configuration with narrowband emission at 445 nm is used as pump source. At a pump power of 680 mW, a maximum UV power of 16 μW in continuous-wave operation at 222.5 nm is achieved. This concept enables a compact diode laser-based system emitting in the deep ultraviolet spectral range.

  5. A flexible super-capacitive solid-state power supply for miniature implantable medical devices.

    Science.gov (United States)

    Meng, Chuizhou; Gall, Oren Z; Irazoqui, Pedro P

    2013-12-01

    We present a high-energy local power supply based on a flexible and solid-state supercapacitor for miniature wireless implantable medical devices. Wireless radio-frequency (RF) powering recharges the supercapacitor through an antenna with an RF rectifier. A power management circuit for the super-capacitive system includes a boost converter to increase the breakdown voltage required for powering device circuits, and a parallel conventional capacitor as an intermediate power source to deliver current spikes during high current transients (e.g., wireless data transmission). The supercapacitor has an extremely high area capacitance of ~1.3 mF/mm(2), and is in the novel form of a 100 μm-thick thin film with the merit of mechanical flexibility and a tailorable size down to 1 mm(2) to meet various clinical dimension requirements. We experimentally demonstrate that after fully recharging the capacitor with an external RF powering source, the supercapacitor-based local power supply runs a full system for electromyogram (EMG) recording that consumes ~670 μW with wireless-data-transmission functionality for a period of ~1 s in the absence of additional RF powering. Since the quality of wireless powering for implantable devices is sensitive to the position of those devices within the RF electromagnetic field, this high-energy local power supply plays a crucial role in providing continuous and reliable power for medical device operations.

  6. RF Pulse compression stabilization at the CTF3 CLIC test facility

    CERN Document Server

    Dubrovskiy, Alexey

    2010-01-01

    In the CTF3 accelerator, the RF produced by each of ten 3 GHz klystrons goes through waveguides, RF pulse compressors and splitters. The RF phase and power transformation of these devices depend on their temperature. The quantitative effect of the room temperature variation on the RF was measured. It is the major source of undesired changes during the CTF3 operation. An RF phaseloop and a compressor temperature stabilization are developed to suppress the phase fluctuation and the power profile change due to the temperature variation. The implementation is transparent for operators, it does not limit anyhow the flexibility of RF manipulations. Expected and measured suppression characteristics will be given.

  7. Wireless Networks with RF Energy Harvesting: A Contemporary Survey

    OpenAIRE

    Lu, Xiao; Wang,Ping; Niyato, Dusit; Kim, Dong In; Han, Zhu

    2014-01-01

    Radio frequency (RF) energy transfer and harvesting techniques have recently become alternative methods to power the next generation wireless networks. As this emerging technology enables proactive energy replenishment of wireless devices, it is advantageous in supporting applications with quality of service (QoS) requirement. In this paper, we present an extensive literature review on the research progresses in wireless networks with RF energy harvesting capability, referred to as RF energy ...

  8. High power operation with beam of a CLIC pets equipped with on/off mechanism

    CERN Document Server

    Syratchev, I; Dubrovskiy, A; Skowronski, P; Ruber, R

    2012-01-01

    One of the feasibility issues of the CLIC two-beam scheme, is the possibility of rapidly switching off the rf power production in an individual Power Extraction and Transfer Structures (PETS) in case of breakdowns, either in the PETS or one of the main beam accelerating structures. The proposed solution is to use a variable external reflector connected to the PETS. When activated, this scheme allows us to gradually manipulate the rf power transfer to the accelerating structure and to reduce the rf power production in the PETS itself by a factor of 4. Recently the first operation of the Two Beam Test Stand (TBTS) PETS equipped with an ON/OFF mechanism was performed in CTF3. In this paper we will present the results of the PETS operation when powered by the drive beam up to high peak power levels (>100 MW) and compare them to expectations.

  9. Characteristics of single and dual radio-frequency (RF) plasma sheaths

    Institute of Scientific and Technical Information of China (English)

    DAI Zhong-ling; WANG You-nian

    2006-01-01

    The characteristics of radio-frequency(RF)plasma sheaths have been topics of much scientific study for decades,and have also been of great importance in the manufacture of integrated circuits and fabricating microelectromechanical systems (MEMS),as well as in the study of physical phenomena in dusty plasmas.The sheaths behave special properties under various situations where they can be treated as collisionless or collisional,single- or dual-RF,one- or two-dimensional (1D or 2D) sheaths,etc.This paper reviews our recent progress on the dynamics of RF plasma sheaths using a fluid method that includes the fluid equations and Poission's equation coupled with an equivalent circuit model and a hybrid method in which the fluid model is combined with the Monte-Carlo (MC)method.The structures of RF sheaths behave differently in various situations and plasma parameters such as the ion density,electron temperature,as well as the external parameters such as the applied frequency,power,gas pressure,magnetic field,are crucial for determining the characteristics of plasma sheaths.

  10. Numerical simulation of the RF plasma discharge in the Linac4 H- ion source

    Science.gov (United States)

    Mattei, S.; Nishida, K.; Onai, M.; Lettry, J.; Tran, M. Q.; Hatayama, A.

    2017-08-01

    This paper presents a Particle-In-Cell Monte Carlo Collision simulation of the Radio-Frequency (RF) plasma heating in the Linac4 H- ion source at CERN. The model self-consistently takes into account the electromagnetic field generated by the RF coil, the external static magnetic fields and the resulting plasma response, including a kinetic description of the charged species (e-, H+, H2-, H3+, H-), as well as the atomic and molecular (vibrationally resolved) populations. The simulation is performed for the nominal operational condition of 40 kW RF power and 3 Pa H2 pressure. Results show that the plasma spatial distribution is non-uniform in the plasma chamber, with a density peak of ne = 5 . 1019 m-3 in the RF coil region. In the filter field region the electron density drops by two orders of magnitude, with a substantial reduction of the electron energy as well. This results in a ratio e/H- ≈ 1 in the extraction region. The vibrational population is characterized by a two temperature distribution, with the high vibrational states showing a factor 2 higher termperature. A very good agreement is found between the simulation results and optical emission spectroscopy measurement performed on a dedicated test stand at CERN.

  11. RF design of X-band RF deflector for femtosecond diagnostics of LCLS electron beam

    Science.gov (United States)

    Dolgashev, Valery A.; Wang, Juwen

    2012-12-01

    We designed a successful constant impedance traveling wave X-band rf deflector for electron beam diagnostics at the 14 GeV SLAC Linac Coherent Light Source (LCLS). This is the first practical deflector built with a waveguide coupler. The 1-meter rf deflector produces 24 MeV peak transverse kick when powered with 20 MW of 11.424 GHz rf. The design is based on our experience with high gradient X-band accelerating structures. Several deflectors of this design have been built at SLAC and are currently in use. Here we describe the design and distinguishing features of this device.

  12. Influence of the electrical power applied to the target on the optical and structural properties of ZrON films produced via RF magnetron sputtering in a reactive atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Pinzón, M.J. [Grupo de Ciencia de Materiales y Superficies, Departamento de Física, Universidad Nacional de Colombia, AA 14490 Bogotá (Colombia); Alfonso, J.E., E-mail: jealfonsoo@unal.edu.co [Grupo de Ciencia de Materiales y Superficies, Departamento de Física, Universidad Nacional de Colombia, AA 14490 Bogotá (Colombia); Olaya, J.J. [Grupo de Ciencia de Materiales y Superficies, Departamento de Física, Universidad Nacional de Colombia, AA 14490 Bogotá (Colombia); Cubillos, G.I.; Romero, E. [Grupo de Materiales y Procesos Químicos, Universidad Nacional de Colombia, AA 14490 Bogotá (Colombia)

    2014-12-01

    The influence of the variation of electrical power applied to the target on the morphology and optical properties of zirconium oxynitride - zirconium oxide (ZrON) films deposited via RF magnetron sputtering on common glass substrates in a reactive atmosphere of N{sub 2}/O{sub 2}, with a flow ratio ΦN{sub 2}/ΦO{sub 2} of 1.25 was investigated. The crystallographic structure of the films was established through X-ray diffraction (XRD), the morphology was evaluated through scanning electron microscopy (SEM) and atomic force microscopy (AFM), and the optical behavior was evaluated through transmittance measurements. The XRD analysis showed that the films grew with mixed crystalline structures: monoclinic (ZrO{sub 2}) and body-centered cubic (Zr{sub 2}ON{sub 2}). SEM analysis showed that the films grew with a homogeneous morphology, and AFM results established that as the electrical power applied to the target increased, there were changes in the grain size and the roughness of the films. The thickness, refractive index, and absorption coefficient of the films were calculated using the values of the transmittance through the Swanepoel method. Additionally, the energy band gap was determined via analysis of the free interference region. - Highlights: • We growth zirconium oxynitride films by RF magnetron sputtering in reactive atmosphere. • We determine the influence of the electrical power applied at the target in optical and structural properties. • We determine the crystallite size, grain size and roughness of the zirconium oxynitride films. • We determine the optical parameters such refractive index of the zirconium oxynitride films through Swanepoel method. • We calculated the absorption coefficient and optical band gap of the zirconium oxynitride films.

  13. Simultaneous radiofrequency (RF) heating and magnetic resonance (MR) thermal mapping using an intravascular MR imaging/RF heating system.

    Science.gov (United States)

    Qiu, Bensheng; El-Sharkawy, Abdel-Monem; Paliwal, Vaishali; Karmarkar, Parag; Gao, Fabao; Atalar, Ergin; Yang, Xiaoming

    2005-07-01

    Previous studies have confirmed the possibility of using an intravascular MR imaging guidewire (MRIG) as a heating source to enhance vascular gene transfection/expression. This motivated us to develop a new intravascular system that can perform MR imaging, radiofrequncy (RF) heating, and MR temperature monitoring simultaneously in an MR scanner. To validate this concept, a series of mathematical simulations of RF power loss along a 0.032-inch MRIG and RF energy spatial distribution were performed to determine the optimum RF heating frequency. Then, an RF generator/amplifier and a filter box were built. The possibility for simultaneous RF heating and MR thermal mapping of the system was confirmed in vitro using a phantom, and the obtained thermal mapping profile was compared with the simulated RF power distribution. Subsequently, the feasibility of simultaneous RF heating and temperature monitoring was successfully validated in vivo in the aorta of living rabbits. This MR imaging/RF heating system offers a potential tool for intravascular MR-mediated, RF-enhanced vascular gene therapy.

  14. Comparison of childhood thyroid cancer prevalence among 3 areas based on external radiation dose after the Fukushima Daiichi nuclear power plant accident: The Fukushima health management survey.

    Science.gov (United States)

    Ohira, Tetsuya; Takahashi, Hideto; Yasumura, Seiji; Ohtsuru, Akira; Midorikawa, Sanae; Suzuki, Satoru; Fukushima, Toshihiko; Shimura, Hiroki; Ishikawa, Tetsuo; Sakai, Akira; Yamashita, Shunichi; Tanigawa, Koichi; Ohto, Hitoshi; Abe, Masafumi; Suzuki, Shinichi

    2016-08-01

    The 2011 Great East Japan Earthquake led to a subsequent nuclear accident at the Fukushima Daiichi Nuclear Power Plant. In its wake, we sought to examine the association between external radiation dose and thyroid cancer in Fukushima Prefecture. We applied a cross-sectional study design with 300,476 participants aged 18 years and younger who underwent thyroid examinations between October 2011 and June 2015. Areas within Fukushima Prefecture were divided into three groups based on individual external doses (≥1% of 5 mSv, <99% of 1 mSv/y, and the other). The odds ratios (ORs) and 95% confidence intervals of thyroid cancer for all areas, with the lowest dose area as reference, were calculated using logistic regression models adjusted for age and sex. Furthermore, the ORs of thyroid cancer for individual external doses of 1 mSv or more and 2 mSv or more, with the external dose less than 1 mSv as reference, were calculated. Prevalence of thyroid cancer for the location groups were 48/100,000 for the highest dose area, 36/100,000 for the middle dose area, and 41/100,000 for the lowest dose area. Compared with the lowest dose area, age-, and sex-adjusted ORs (95% confidence intervals) for the highest-dose and middle-dose areas were 1.49 (0.36-6.23) and 1.00 (0.67-1.50), respectively. The duration between accident and thyroid examination was not associated with thyroid cancer prevalence. There were no significant associations between individual external doses and prevalence of thyroid cancer. External radiation dose was not associated with thyroid cancer prevalence among Fukushima children within the first 4 years after the nuclear accident.

  15. Comparison of childhood thyroid cancer prevalence among 3 areas based on external radiation dose after the Fukushima Daiichi nuclear power plant accident

    Science.gov (United States)

    Ohira, Tetsuya; Takahashi, Hideto; Yasumura, Seiji; Ohtsuru, Akira; Midorikawa, Sanae; Suzuki, Satoru; Fukushima, Toshihiko; Shimura, Hiroki; Ishikawa, Tetsuo; Sakai, Akira; Yamashita, Shunichi; Tanigawa, Koichi; Ohto, Hitoshi; Abe, Masafumi; Suzuki, Shinichi

    2016-01-01

    Abstract The 2011 Great East Japan Earthquake led to a subsequent nuclear accident at the Fukushima Daiichi Nuclear Power Plant. In its wake, we sought to examine the association between external radiation dose and thyroid cancer in Fukushima Prefecture. We applied a cross-sectional study design with 300,476 participants aged 18 years and younger who underwent thyroid examinations between October 2011 and June 2015. Areas within Fukushima Prefecture were divided into three groups based on individual external doses (≥1% of 5 mSv, <99% of 1 mSv/y, and the other). The odds ratios (ORs) and 95% confidence intervals of thyroid cancer for all areas, with the lowest dose area as reference, were calculated using logistic regression models adjusted for age and sex. Furthermore, the ORs of thyroid cancer for individual external doses of 1 mSv or more and 2 mSv or more, with the external dose less than 1 mSv as reference, were calculated. Prevalence of thyroid cancer for the location groups were 48/100,000 for the highest dose area, 36/100,000 for the middle dose area, and 41/100,000 for the lowest dose area. Compared with the lowest dose area, age-, and sex-adjusted ORs (95% confidence intervals) for the highest-dose and middle-dose areas were 1.49 (0.36–6.23) and 1.00 (0.67–1.50), respectively. The duration between accident and thyroid examination was not associated with thyroid cancer prevalence. There were no significant associations between individual external doses and prevalence of thyroid cancer. External radiation dose was not associated with thyroid cancer prevalence among Fukushima children within the first 4 years after the nuclear accident. PMID:27583855

  16. RF gymnastics in synchrotrons

    CERN Document Server

    Garoby, R

    2011-01-01

    The RF systems installed in synchrotrons can be used to change the longitudinal beam characteristics. 'RF gymnastics' designates manipulations of the RF parameters aimed at providing such non-trivial changes. Some keep the number of bunches constant while changing bunch length, energy spread, emittance, or distance between bunches. Others are used to change the number of bunches. After recalling the basics of longitudinal beam dynamics in a hadron synchrotron, this paper deals with the most commonly used gymnastics. Their principle is described as well as their performance and limitations.

  17. RF Gymnastics in Synchrotrons

    CERN Document Server

    Garoby, R

    2005-01-01

    The RF systems installed in synchrotrons can be used to change the longitudinal beam characteristics. "RF gymnastics" designates manipulations of the RF parameters aimed at providing such non-trivial changes. Some keep the number of bunches constant while changing bunch length, energy spread, emittance or distance between bunches. Others are used to change the number of bunches. After recalling the basics of longitudinal beam dynamics in a hadron synchrotron, this paper deals with the most commonly used gymnastics. Their principle is described as well as their performance and limitations.

  18. Geolocation of RF signals

    CERN Document Server

    Progri, Ilir

    2011-01-01

    ""Geolocation of RF Signals - Principles and Simulations"" offers an overview of the best practices and innovative techniques in the art and science of geolocation over the last twenty years. It covers all research and development aspects including theoretical analysis, RF signals, geolocation techniques, key block diagrams, and practical principle simulation examples in the frequency band from 100 MHz to 18 GHz or even 60 GHz. Starting with RF signals, the book progressively examines various signal bands - such as VLF, LF, MF, HF, VHF, UHF, L, S, C, X, Ku, and, K and the corresponding geoloca

  19. RF Processing of the Couplers for the SNS Superconducting Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Y.Kang; I.E. Campisi; D. Stout; A. Vassioutchenko; M. Stirbet; M. Drury; T. Powers

    2005-07-10

    All eighty-one fundamental power couplers for the 805 MHz superconducting cavities of the SNS linac have been RF conditioned and installed in the cryomodules successfully. The couplers were RF processed at JLAB or at the SNS in ORNL: more than forty couplers have been RF conditioned in the SNS RF Test Facility (RFTF) after the first forty couplers were conditioned at JLAB. The couplers were conditioned up to 650 kW forward power at 8% duty cycle in traveling and standing waves. They were installed on the cavities in the cryomodules and then assembled with the airside waveguide transitions. The couplers have been high power RF tested with satisfactory accelerating field gradients in the cooled cavities.

  20. Topology optimized RF MEMS switches

    DEFF Research Database (Denmark)

    Philippine, M. A.; Zareie, H.; Sigmund, Ole

    2013-01-01

    Topology optimization is a rigorous and powerful method that should become a standard MEMS design tool - it can produce unique and non-intuitive designs that meet complex objectives and can dramatically improve the performance and reliability of MEMS devices. We present successful uses of topology...... optimization for an RF MEM capacitive switch. Extensive experimental data confirms that the switches perform as designed by the optimizations, and that our simulation models are accurate. A subset of measurements are presented here. Broader results have been submitted in full journal format....