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Sample records for ghz high power

  1. High power, 140 GHz gyrotron

    International Nuclear Information System (INIS)

    Kreischer, K.E.; Temkin, R.J.; Mulligan, W.J.; MacCabe, S.; Chaplya, R.

    1982-01-01

    The design and construction of a pulsed 100 kW, 140 GHz gyrotron is described. Initial gyrotron operation is expected in early 1982. Advances in gyrotron theory have also been carried out in support of this experimental research. The application of gyrotrons to plasma diagnostics is also under investigation. (author)

  2. 30 GHz High Power Production for CLIC

    CERN Document Server

    Syratchev, I V

    2006-01-01

    The CLIC Power Extraction and Transfer Structure (PETS) is a passive microwave device in which bunches of the drive beam interact with the impedance of the periodically loaded waveguide and excite preferentially the synchronous TM01 mode at 30 GHz. The RF power produced (several hundred MW) is collected at the downstream end of the structure by means of the Power Extractor and conveyed to the main linac structure. The PETS geometry is a result of multiple compromises between beam stability along a single decelerator sector (600 m) and the active length of the structure to match the main linac RF power needs and layout. Surface electric and magnetic fields, power extraction method, HOM damping, ON/OFF capability and fabrication technology were all evaluated to provide a reliable design.

  3. An 8–18 GHz broadband high power amplifier

    International Nuclear Information System (INIS)

    Wang Lifa; Yang Ruixia; Li Yanlei; Wu Jingfeng

    2011-01-01

    An 8–18 GHz broadband high power amplifier (HPA) with a hybrid integrated circuit (HIC) is designed and fabricated. This HPA is achieved with the use of a 4-fingered micro-strip Lange coupler in a GaAs MMIC process. In order to decrease electromagnetic interference, a multilayer AlN material with good heat dissipation is adopted as the carrier of the power amplifier. When the input power is 25 dBm, the saturated power of the continuous wave (CW) outputted by the power amplifier is more than 39 dBm within the frequency range of 8–13 GHz, while it is more than 38.6 dBm within other frequency ranges. We obtain the peak power output, 39.4 dBm, at the frequency of 11.9 GHz. In the whole frequency band, the power-added efficiency is more than 18%. When the input power is 18 dBm, the small signal gain is 15.7 ± 0.7 dB. The dimensions of the HPA are 25 × 15 × 1.5 mm 3 . (semiconductor integrated circuits)

  4. High power testing of a 17 GHz photocathode RF gun

    International Nuclear Information System (INIS)

    Chen, S.C.; Danly, B.G.; Gonichon, J.

    1995-01-01

    The physics and technological issues involved in high gradient particle acceleration at high microwave (RF) frequencies are under study at MIT. The 17 GHz photocathode RF gun has a 1 1/2 cell (π mode) room temperature cooper cavity. High power tests have been conducted at 5-10 MW levels with 100 ns pulses. A maximum surface electric field of 250 MV/m was achieved. This corresponds to an average on-axis gradient of 150 MeV/m. The gradient was also verified by a preliminary electron beam energy measurement. Even high gradients are expected in our next cavity design

  5. A program of high power microwave source research and development from 8 GHz to 600 GHz

    International Nuclear Information System (INIS)

    Granatstein, V.L.; Antonsen, T.M. Jr.; Bidwell, S.; Booske, J.; Carmel, Y.; Destler, W.W.; Kehs, R.A.; Latham, P.E.; Levush, B.; Lou, W.R.; Mayergoyz, I.D.; Minami, K.; Radack, D.J.

    1990-01-01

    We review research results both on a plasma filled, backward wave oscillator (BWO), and on a free electron laser (FEL) driven by a sheet electron beam. Recently, it was demonstrated that a plasma filled BWO driven by an intense relativistic electron beam can generate hundreds of megawatts of microwave radiation at an unusually high efficiency of 40% compared with a typical efficiency of ∼10% in a BWO without a background plasma. Furthermore, the enhanced efficiency can be maintained even for large electron beam currents approaching the vacuum space charge limiting current, and we anticipate this might hold even for larger current values. Theoretical studies and numerical simulations indicate that the enhanced efficiency as well as a lower value for the start oscillation current in the linear regime may be due to the finite length of the BWO circuit coupled with modification of the dispersion relation due to the background plasma. In the case of our FEL studies, we present designs for a 1 MW, CW, tapered FEL amplifier operating at frequencies of 280 GHz and 560 GHz. A short wiggler period (ell w ∼ 1 cm) is combined with a sheet beam of electrons having energy ∼1 MeV. Depressed collector techniques would allow the main power supply rating to be reduced to ∼200 kV. Efficient sheet beam transport (>99%) has been demonstrated through 10 wiggler periods, and transport through 60 wiggler periods is currently under study. Finally, plans for a proof-of-principle tapered FEL amplifier experiment at 94 GHz are presented. 8 refs., 7 figs

  6. 1 GHz GaAs Buck Converter for High Power Amplifier Modulation Applications

    NARCIS (Netherlands)

    Busking, E.B.; Hek, A.P. de; Vliet, F.E. van

    2012-01-01

    A fully integrated 1 GHz buck converter output stage, including on-chip inductor and DC output filtering has been realized, in a standard high-voltage breakdown GaAs MMIC technology. This is a significant step forward in designing highspeed power control of supply-modulated HPAs (high power

  7. Design and High Power Measurements of a 3 GHz Rotary Joint for Medical Applications

    CERN Document Server

    Degiovanni, Alberto; Garlasche, Marco; Giner-Navarro, Jorge; Magagnin, Paolo; Mcmonagle, Gerard; Syratchev, Igor; Wuensch, Walter

    2016-01-01

    The TUrning LInac for Protontherapy (TULIP) project requires the transport of RF power from modulator/klystron systems at rest on the floor to the linac structures mounted on a rotating gantry, via a waveguide system that can operate over a range of angles of rotation. A waveguide rotary joint capable of transporting RF power at 3 GHz and up to 20 MW has been designed and built in collaboration between TERA Foundation, CERN Beams and CERN Engineering Departments. A high-power test of the prototype has been performed at the CLIC Test Facility (CTF3), at CERN. The design and the results of the tests are reported in this article.

  8. High power tests of an electroforming cavity operating at 11.424 GHz

    Science.gov (United States)

    Dolgashev, V. A.; Gatti, G.; Higashi, Y.; Leonardi, O.; Lewandowski, J. R.; Marcelli, A.; Rosenzweig, J.; Spataro, B.; Tantawi, S. G.; Yeremian, D. A.

    2016-03-01

    The achievement of ultra high accelerating gradients is mandatory in order to fabricate compact accelerators at 11.424 GHz for scientific and industrial applications. An extensive experimental and theoretical program to determine a reliable ultra high gradient operation of the future linear accelerators is under way in many laboratories. In particular, systematic studies on the 11.424 GHz frequency accelerator structures, R&D on new materials and the associated microwave technology are in progress to achieve accelerating gradients well above 120 MeV/m. Among the many, the electroforming procedure is a promising approach to manufacture high performance RF devices in order to avoid the high temperature brazing and to produce precise RF structures. We report here the characterization of a hard high gradient RF accelerating structure at 11.424 GHz fabricated using the electroforming technique. Low-level RF measurements and high power RF tests carried out at the SLAC National Accelerator Laboratory on this prototype are presented and discussed. In addition, we present also a possible layout where the water-cooling of irises based on the electroforming process has been considered for the first time.

  9. High power tests of dressed supconducting 1.3 GHz RF cavities

    Energy Technology Data Exchange (ETDEWEB)

    Hocker, A.; Harms, E.R.; Lunin, A.; Sukhanov, A.; /Fermilab

    2011-03-01

    A single-cavity test cryostat is used to conduct pulsed high power RF tests of superconducting 1.3 GHz RF cavities at 2 K. The cavities under test are welded inside individual helium vessels and are outfitted ('dressed') with a fundamental power coupler, higher-order mode couplers, magnetic shielding, a blade tuner, and piezoelectric tuners. The cavity performance is evaluated in terms of accelerating gradient, unloaded quality factor, and field emission, and the functionality of the auxiliary components is verified. Test results from the first set of dressed cavities are presented here.

  10. Status and outlook for high power processing of 1.3 GHz TESLA multicell cavities

    International Nuclear Information System (INIS)

    Kirchgessner, J.; Barnes, P.; Graber, J.; Metzger, D.; Mofat, D.; Muller, H.; Padamsee, H.; Sears, J.; Tigner, M.; Matheisen, A.

    1993-01-01

    In order to increase the usable accelerating gradient in Superconducting TESLA cavities, the field emission threshold barrier must be raised. As has been previously demonstrated on S-band cavities, a way to accomplish this is with the use of high peak power RF processing. A transmitter with a peak power of 2 Mwatt and 300 μsec pulse length has been assembled and has been used to process TESLA cavities. Several five cell TESLA cavities at 1.3 GHz have been manufactured for this purpose. This transmitter and the cavities will be described and the results of the tests will be presented

  11. 8 GHz, high power, microwave system for heating of thermonuclear plasmas

    International Nuclear Information System (INIS)

    Di Giovenale, S.; Fortunato, T.; Mirizzi, F.; Roccon, M.; Sassi, M.; Tuccillo, A.A.; Maffia, G.; Baldi, L.

    1993-01-01

    The Frascati Tokamak Upgrade (FTU) is a machine included in the European Thermonuclear Fusion Program aimed at investigating high density plasmas in the presence of powerful additional RF heating systems. The Lower Hybrid Resonant Heating (LHRH) system, based on 9 independent modules, works at 8 GHz, and will generate, at full performances, a total amount of 9 MW, in the pulsed regime (pulse length = 1 s, duty cycle = 1/600). The microwave power source is a gyrotron oscillator, developed by Thomson Tubes Electroniques (France) for this specific application, and capable of producing up to 1 MW. An overmoded, low loss, circular waveguide transmits the RF power toward the plasma; an array of 12x4 rectangular waveguides (the 'grill') launches this power into the plasma. The paper describes the LHRH system for FTU and analyses both its main performances and experimental results

  12. Initial results for a 170 GHz high power ITER waveguide component test stand

    Science.gov (United States)

    Bigelow, Timothy; Barker, Alan; Dukes, Carl; Killough, Stephen; Kaufman, Michael; White, John; Bell, Gary; Hanson, Greg; Rasmussen, Dave

    2014-10-01

    A high power microwave test stand is being setup at ORNL to enable prototype testing of 170 GHz cw waveguide components being developed for the ITER ECH system. The ITER ECH system will utilize 63.5 mm diameter evacuated corrugated waveguide and will have 24 >150 m long runs. A 170 GHz 1 MW class gyrotron is being developed by Communications and Power Industries and is nearing completion. A HVDC power supply, water-cooling and control system has been partially tested in preparation for arrival of the gyrotron. The power supply and water-cooling system are being designed to operate for >3600 second pulses to simulate the operating conditions planned for the ITER ECH system. The gyrotron Gaussian beam output has a single mirror for focusing into a 63.5 mm corrugated waveguide in the vertical plane. The output beam and mirror are enclosed in an evacuated duct with absorber for stray radiation. Beam alignment with the waveguide is a critical task so a combination of mirror tilt adjustments and a bellows for offsets will be provided. Analysis of thermal patterns on thin witness plates will provide gyrotron mode purity and waveguide coupling efficiency data. Pre-prototype waveguide components and two dummy loads are available for initial operational testing of the gyrotron. ORNL is managed by UT-Battelle, LLC, for the U.S. Dept. of Energy under Contract DE-AC-05-00OR22725.

  13. High linearity 5.2-GHz power amplifier MMIC using CPW structure technology with a linearizer circuit

    International Nuclear Information System (INIS)

    Wu Chiasong; Lin Tah-Yeong; Wu Hsien-Ming

    2010-01-01

    A built-in linearizer was applied to improve the linearity in a 5.2-GHz power amplifier microwave monolithic integrated circuit (MMIC), which was undertaken with 0.15-μm AlGaAs/InGaAs D-mode PHEMT technology. The power amplifier (PA) was studied taking into account the linearizer circuit and the coplanar waveguide (CPW) structures. Based on these technologies, the power amplifier, which has a chip size of 1.44 x 1.10 mm 2 , obtained an output power of 13.3 dBm and a power gain of 14 dB in the saturation region. An input third-order intercept point (HP 3 ) of -3 dBm, an output third-order intercept point (OIP 3 ) of 21.1 dBm and a power added efficiency (PAE) of 22% were attained, respectively. Finally, the overall power characterization exhibited high gain and high linearity, which illustrates that the power amplifier has a compact circuit size and exhibits favorable RF characteristics. This power circuit demonstrated high RF characterization and could be used for microwave power circuit applications at 5.2 GHz. (semiconductor integrated circuits)

  14. High-Power Plasma Switch for 11.4 GHz Microwave Pulse Compressor

    International Nuclear Information System (INIS)

    Hirshfield, Jay L.

    2010-01-01

    Results obtained in several experiments on active RF pulse compression at X-band using a magnicon as the high-power RF source are presented. In these experiments, microwave energy was stored in high-Q TE01 and TE02 modes of two parallel-fed resonators, and then discharged using switches activated with rapidly fired plasma discharge tubes. Designs and high-power tests of several versions of the compressor are described. In these experiments, coherent pulse superposition was demonstrated at a 5-9 MW level of incident power. The compressed pulses observed had powers of 50-70 MW and durations of 40-70 ns. Peak power gains were measured to be in the range of 7:1-11:1 with efficiency in the range of 50-63%.

  15. A 1–2 GHz high linearity transformer-feedback power-to-current LNA

    NARCIS (Netherlands)

    Li, X.; Serdijn, W.A.; Woestenburg, B.E.M.; Bij de Vaate, J.G.

    2009-01-01

    This paper demonstrates that a double-loop transformer-feedback power-to-current low noise amplifier, to be implemented in a 0.2 lm GaAs p-HEMT IC process, is able to obtain a noise figure less than 0.8 dB, an input return loss less than -12 dB, a flat voltage-to-current signal transfer of 180 mS,

  16. 45-GHz and 60-GHz 90 nm CMOS power amplifiers with a fully symmetrical 8-way transformer power combiner

    Institute of Scientific and Technical Information of China (English)

    Zhengdong JIANG; Kaizhe GUO; Peng HUANG; Yiming FAN; Chenxi ZHAO; Yongling BAN; Jun LIU; Kai KANG

    2017-01-01

    In this paper,45 GHz and 60 GHz power amplifiers (PAs) with high output power have been successfully designed by using 90 nm CMOS process.The 45 GHz (60 GHz) PA consists of two (four) differential stages.The sizes of transistors have been designed in an appropriate way so as to trade-off gain,efficiency and stability.Due to limited supply voltage and low breakdown voltage of CMOS MOSFET compared with the traditional Ⅲ-Ⅴ technologies,the technique of power combining has been applied to achieve a high output power.In particular,a novel 8-way distributed active transformer power combiner has been proposed for realizing such mm-wave PA.The proposed transformer combiner with a fully symmetrical layout can improve its input impedance balance at mm-wave frequency regime significantly.Taking its advantages of this novel transformer based power combiner,our realized 45 GHz (60 GHz) mm-wave PA has achieved the gain of 20.3 dB (16.8 dB),the maximum PAE of 14.5% (13.4%) and the saturated output power of 21 dBm (21 dBm) with the 1.2 V supply voltage.

  17. Design of 0.8–2.7 GHz High Power Class-F Harmonic-Tuned Power Amplifier with Parasitic Compensation Circuit

    Directory of Open Access Journals (Sweden)

    Zhiqun Cheng

    2017-01-01

    Full Text Available The design, implementation, and measurements of a high efficiency and high power wideband GaN HEMT power amplifier are presented. Package parasitic effect is reduced significantly by a novel compensation circuit design to improve the accuracy of impedance matching. An improved structure is proposed based on the traditional Class-F structure with all even harmonics and the third harmonic effectively controlled, respectively. Also the stepped-impedance matching method is applied to the third harmonic control network, which has a positive effect on the expansion bandwidth. CGH40025F power transistor is utilized to build the power amplifier working at 0.8 to 2.7 GHz, with the measured saturated output power 20–50 W, drain efficiency 52%–76%, and gain level above 10 dB. The second and the third harmonic suppression levels are maintained at −16 to −36 dBc and −16 to −33 dBc, respectively. The simulation and the measurement results of the proposed power amplifier show good consistency.

  18. Components for transmission of very high power mm-waves (200 kW at 28, 70 and 140 GHz) in overmoded circular waveguides

    International Nuclear Information System (INIS)

    Thumm, M.; Erckmann, V.; Kasparek, W.; Kumric, H.; Mueller, G.A.; Schueller, P.G.; Wilhelm, R.

    1986-03-01

    Optimized overmoded circular waveguide components of transmission lines developed for high-power (200 kW) millimeter wave applications at 28, 70 and 140 GHz, as e.g. electron cyclotron resonance heating (ECRH) of plasmas for thermonuclear fusion research with gyrotrons, are described. Axisymmetric, narrow, pencil-like beams with well-defined polarization (HE11 hybrid mode) are used at open-ended corrugated waveguide antennas. The HE11 mode is generated from TEsub(On) gyrotron modes by the two multi-step mode conversion processes: (1) TEsub(On)->TE 01 ->TE 11 ->HE 11 or (2) TEsub(On)->TE 01 ->TM 11 ->HE 11 . This paper reports computer-aided analyses and measurements on mode transducer systems of the first type at 28 and 70 GHz and of the second type at 140 GHz. In all cases the overall efficiency of the complete mode conversion sequence in the desired mode is approximately (92-95)%. The mode purity in the transmission lines is conserved by using corrugated gradual waveguide bends with optimized curvature distribution and diameter tapers with non-linear contours. Highly efficient corrugated-wall mode selective filters decouple the different waveguide sections. Mode content and reflected power are determined by a novel device (k-spectrometer). Absolute power calibration is done with newly developed calorimetric loads using an organic absorbing fluid. (orig.) [de

  19. Design of a high-power, high-gain, 2nd harmonic, 22.848 GHz gyroklystron

    Energy Technology Data Exchange (ETDEWEB)

    Veale, M. [University of California, Berkeley, CA, 24720 (United States); Purohit, P. [Qualcomm Technologies, Inc. USA (United States); Lawson, W. [University of Maryland, College Park, MD 20742 (United States)

    2013-08-15

    In this paper we consider the design of a four-cavity, high-gain K-band gyroklystron experiment for high gradient structure testing. The frequency doubling gyroklystron utilizes a beam voltage of 500 kV and a beam current of 200 A from a magnetron injection gun (MIG) originally designed for a lower-frequency device. The microwave circuit features input and gain cavities in the circular TE{sub 011} mode and penultimate and output cavities that operate at the second harmonic in the TE{sub 021} mode. We investigate the MIG performance and study the behavior of the circuit for different values of perpendicular to parallel velocity ratio (α= V{sub ⊥}/ V{sub z}). This microwave tube is expected to be able to produce at least 20 MW of power in 1μs pulses at a repetition rate of at least 120 Hz. A maximum efficiency of 26% and a large signal gain of 58 dB under zero-drive stable conditions were simulated for a velocity ratio equal to 1.35.

  20. Fabrication of Very High Efficiency 5.8 GHz Power Amplifiers using AlGaN HFETs on SiC Substrates for Wireless Power Transmission

    Science.gov (United States)

    Sullivan, Gerry

    2001-01-01

    For wireless power transmission using microwave energy, very efficient conversion of the DC power into microwave power is extremely important. Class E amplifiers have the attractive feature that they can, in theory, be 100% efficient at converting, DC power to RF power. Aluminum gallium nitride (AlGaN) semiconductor material has many advantageous properties, relative to silicon (Si), gallium arsenide (GaAs), and silicon carbide (SiC), such as a much larger bandgap, and the ability to form AlGaN/GaN heterojunctions. The large bandgap of AlGaN also allows for device operation at higher temperatures than could be tolerated by a smaller bandgap transistor. This could reduce the cooling requirements. While it is unlikely that the AlGaN transistors in a 5.8 GHz class E amplifier can operate efficiently at temperatures in excess of 300 or 400 C, AlGaN based amplifiers could operate at temperatures that are higher than a GaAs or Si based amplifier could tolerate. Under this program, AlGaN microwave power HFETs have been fabricated and characterized. Hybrid class E amplifiers were designed and modeled. Unfortunately, within the time frame of this program, good quality HFETs were not available from either the RSC laboratories or commercially, and so the class E amplifiers were not constructed.

  1. Texture-enhanced Al-Cu electrodes on ultrathin Ti buffer layers for high-power durable 2.6 GHz SAW filters

    Science.gov (United States)

    Fu, Sulei; Wang, Weibiao; Xiao, Li; Lu, Zengtian; Li, Qi; Song, Cheng; Zeng, Fei; Pan, Feng

    2018-04-01

    Achieving high resistance to acoustomigration and electromigration in the electrodes used in high-power and high-frequency surface acoustic wave (SAW) filters is important to mobile communications development. In this study, the effects of the Ti buffer layers on the textures and acoustomigration and electromigration resistances of the Al-Cu electrodes were studied comprehensively. The results demonstrate that both power durability and electromigration lifetime are positively correlated with the Al-Cu electrode texture quality. Ultrathin (˜2 nm) Ti can lead to the strongest Al-Cu (111) textured electrodes, with a full width at half maximum of the rocking curve of 2.09°. This represents a remarkable enhancement of the power durability of high-frequency 2.6 GHz SAW filters from 29 dBm to 35 dBm. It also produces lifetime almost 7 times longer than those of electrodes without Ti buffer layers in electromigration tests. X-ray diffraction and transmission electron microscopy analyses revealed that these improved acoustomigration and electromigration resistances can be attributed primarily to the reductions in overall and large-angle grain boundaries in the highly Al-Cu (111) textured electrodes. Furthermore, the growth mechanism of highly Al-Cu texture films is discussed in terms of surface-interface energy balance.

  2. InP MMIC Chip Set for Power Sources Covering 80-170 GHz

    Science.gov (United States)

    Ngo, Catherine

    2001-01-01

    We will present a Monolithic Millimeter-wave Integrated Circuit (MMIC) chip set which provides high output-power sources for driving diode frequency multipliers into the terahertz range. The chip set was fabricated at HRL Laboratories using a 0.1-micrometer gate-length InAlAs/InGaAs/InP high electron mobility transistor (HEMT) process, and features transistors with an f(sub max) above 600 GHz. The HRL InP HEMT process has already demonstrated amplifiers in the 60-200 GHz range. In this paper, these high frequency HEMTs form the basis for power sources up to 170 GHz. A number of state-of-the-art InP HEMT MMICs will be presented. These include voltage-controlled and fixed-tuned oscillators, power amplifiers, and an active doubler. We will first discuss an 80 GHz voltage-controlled oscillator with 5 GHz of tunability and at least 17 mW of output power, as well as a 120 GHz oscillator providing 7 mW of output power. In addition, we will present results of a power amplifier which covers the full WRIO waveguide band (75-110 GHz), and provides 40-50 mW of output power. Furthermore, we will present an active doubler at 164 GHz providing 8% bandwidth, 3 mW of output power, and an unprecedented 2 dB of conversion loss for an InP HEMT MMIC at this frequency. Finally, we will demonstrate a power amplifier to cover 140-170 GHz with 15-25 mW of output power and 8 dB gain. These components can form a power source in the 155-165 GHz range by cascading the 80 GHz oscillator, W-band power amplifier, 164 GHz active doubler and final 140-170 GHz power amplifier for a stable, compact local oscillator subsystem, which could be used for atmospheric science or astrophysics radiometers.

  3. Impact of High Power Interference Sources in Planning and Deployment of Wireless Sensor Networks and Devices in the 2.4 GHz Frequency Band in Heterogeneous Environments

    Directory of Open Access Journals (Sweden)

    Francisco Falcone

    2012-11-01

    Full Text Available In this work, the impact of radiofrequency radiation leakage from microwave ovens and its effect on 802.15.4 ZigBee-compliant wireless sensor networks operating in the 2.4 GHz Industrial Scientific Medical (ISM band is analyzed. By means of a novel radioplanning approach, based on electromagnetic field simulation of a microwave oven and determination of equivalent radiation sources applied to an in-house developed 3D ray launching algorithm, estimation of the microwave oven’s power leakage is obtained for the complete volume of an indoor scenario. The magnitude and the variable nature of the interference is analyzed and the impact in the radio link quality in operating wireless sensors is estimated and compared with radio channel measurements as well as packet measurements. The measurement results reveal the importance of selecting an adequate 802.15.4 channel, as well as the Wireless Sensor Network deployment strategy within this type of environment, in order to optimize energy consumption and increase the overall network performance. The proposed method enables one to estimate potential interference effects in devices operating within the 2.4 GHz band in the complete scenario, prior to wireless sensor network deployment, which can aid in achieving the most optimal network topology.

  4. 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.

  5. 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.

  6. Design and simulation for the pulse high-voltage DC power supply (HVPS) of 1.2 MW/2.45 GHz HT-7U lower hybrid current drive system

    International Nuclear Information System (INIS)

    Huang Yiyun; Kuang Guangli; Xu Weihua; Liu Baohua; Lin Jianan; Wu Junshuan; Zheng Guanghua; Yang Chunshen

    2000-01-01

    The superconducting tokamak HT-7U has been designed by the Institute of Plasma Physics since 1998 and will be set up before 2003. The 1.2 MW/2.45 GHz HT-7U LHCD (Lower hybrid current drive) system which being the most efficient non-induction device can heat the plasma and drive the plasma current has been efficiently in operation now, and a particular design of the 2.8 MW/-35 kV high-voltage DC power supply has been already completed and will apply to the klystron of LHCD on HT-7 and the future HT-7U, and the project of the power supply has been examined and approved professionally by an authorized group of high-level specialist in the Institute of Plasma Physics. The detailed design of the power supply and the simulation results are referred

  7. A low power 20 GHz comparator in 90 nm COMS technology

    Science.gov (United States)

    Kai, Tang; Qiao, Meng; Zhigong, Wang; Ting, Guo

    2014-05-01

    A low power 20 GHz CMOS dynamic latched regeneration comparator for ultra-high-speed, low-power analog-to-digital converters (ADCs) is proposed. The time constant in both the tracking and regeneration phases of the latch are analyzed based on the small signal model. A dynamic source-common logic (SCL) topology is adopted in the master-slave latch to increase the tracking and regeneration speeds. Implemented in 90 nm CMOS technology, this comparator only occupies a die area of 65 × 150 μm2 with a power dissipation of 14 mW from a 1.2 V power supply. The measurement results show that the comparator can work up to 20 GHz. Operating with an input frequency of 1 GHz, the circuit can oversample up to 20 Giga-sampling-per-second (GSps) with 5 bits resolution; while operating at Nyquist, the comparator can sample up to 20 GSps with 4 bits resolution. The comparator has been successfully used in a 20 GSps flash ADC and the circuit can be also used in other high speed applications.

  8. A compact high-gradient 25 MeV 17 GHz RF linac for free-electron laser research

    International Nuclear Information System (INIS)

    Danly, B.G.; Chen, S.C.; Kreischer, K.E.

    1995-01-01

    A new compact high-gradient (60 MeV/m) high-frequency (17.136 GHz) RF linac is presently under construction by Haimson Research Corp. (HRC) for installation at the MIT Plasma Fusion Center in the High-Gradient Accelerator and High Power Microwave Laboratory. This accelerator will utilize an existing traveling-wave relativistic klystron (TWRK) which is now operation at MIT with 25 MW power, 67 dB gain, and 52% efficiency at 17.136 GHz

  9. An applicable 5.8 GHz wireless power transmission system with rough beamforming to Project Loon

    Directory of Open Access Journals (Sweden)

    Chang-Jun Ahn

    2016-06-01

    Full Text Available In recent, Google proposed the Project Loon being developed with the mission of providing internet access to rural and remote areas using high-altitude balloons. In this paper, we describe an applicable prototype of 5.8 GHz wireless power transmission system with rough beamforming method to Project Loon. From the measurement results, transmit beamforming phased array antenna can transmit power more efficiently compared to a horn antenna and array antenna without beamforming with increasing the transmission distance. For the transmission distance of 1000 mm, transmit beamforming phased array antenna can obtain higher received power about 1.46 times compared to array antenna without transmit beamforming.

  10. High power klystrons for efficient reliable high power amplifiers

    Science.gov (United States)

    Levin, M.

    1980-11-01

    This report covers the design of reliable high efficiency, high power klystrons which may be used in both existing and proposed troposcatter radio systems. High Power (10 kW) klystron designs were generated in C-band (4.4 GHz to 5.0 GHz), S-band (2.5 GHz to 2.7 GHz), and L-band or UHF frequencies (755 MHz to 985 MHz). The tubes were designed for power supply compatibility and use with a vapor/liquid phase heat exchanger. Four (4) S-band tubes were developed in the course of this program along with two (2) matching focusing solenoids and two (2) heat exchangers. These tubes use five (5) tuners with counters which are attached to the focusing solenoids. A reliability mathematical model of the tube and heat exchanger system was also generated.

  11. Megawatt Power Level 120 GHz Gyrotrons for ITER Start-Up

    Energy Technology Data Exchange (ETDEWEB)

    Choi, E M; Marchewka, C; Mastovsky, I; Shapiro, M A; Sirigiri, J R; Temkin, R J [MIT - Plasma Science and Fusion Center, NW16-186, 167 Albany Street, Cambridge, MA 02139 (United States)

    2005-01-01

    We report operation of a 110 GHz gyrotron with 1.67 MW of output power measured in short pulses (3{mu}s) at an efficiency of 42% in the TE{sub 22,6} mode. We also present a preliminary design of a 1 MW, 120 GHz gyrotron for ITER start-up with an efficiency greater than 50%.

  12. Megawatt Power Level 120 GHz Gyrotrons for ITER Start-Up

    International Nuclear Information System (INIS)

    Choi, E M; Marchewka, C; Mastovsky, I; Shapiro, M A; Sirigiri, J R; Temkin, R J

    2005-01-01

    We report operation of a 110 GHz gyrotron with 1.67 MW of output power measured in short pulses (3μs) at an efficiency of 42% in the TE 22,6 mode. We also present a preliminary design of a 1 MW, 120 GHz gyrotron for ITER start-up with an efficiency greater than 50%

  13. An FDMA system concept for 30/20 GHz high capacity domestic satellite service

    Science.gov (United States)

    Berk, G.; Jean, P. N.; Rotholz, E.; White, B. E.

    1982-01-01

    The paper summarizes a feasibility study of a multibeam FDMA satellite system operating in the 30/20 GHz band. The system must accommodate a very high volume of traffic within the restrictions of a 5 kW solar cell array and a 2.5 GHz bandwidth. Multibeam satellite operation reduces the DC power demand and allows reuse of the available bandwidth. Interferences among the beams are brought to acceptable levels by appropriate frequency assignments. A transponder design is presented; it is greatly simplified by the application of a regional concept. System analysis shows that MSK modulation is appropriate for a high-capacity system because it conserves the frequency spectrum. Rain attenuation, a serious problem in this frequency band, is combatted with sufficient power margins and with coding. Link budgets, cost analysis, and weight and power calculations are also discussed. A satellite-routed FDMA system compares favorably in performance and cost with a satellite-switched TDMA system.

  14. Observations of electron heating during 28 GHz microwave power application in proto-MPEX

    Science.gov (United States)

    Biewer, T. M.; Bigelow, T. S.; Caneses, J. F.; Diem, S. J.; Green, D. L.; Kafle, N.; Rapp, J.; Proto-MPEX Team

    2018-02-01

    The Prototype Material Plasma Exposure Experiment at the Oak Ridge National Laboratory utilizes a variety of power systems to generate and deliver a high heat flux plasma onto the surface of material targets. In the experiments described here, a deuterium plasma is produced via a ˜100 kW, 13.56 MHz RF helicon source, to which ˜20 kW of 28 GHz microwave power is applied. The electron density and temperature profiles are measured using a Thomson scattering (TS) diagnostic, and indicate that the electron density is centrally peaked. In the core of the plasma column, the electron density is higher than the cut-off density (˜0.9 × 1019 m-3) for the launched mixture of X- and O-mode electron cyclotron heating waves to propagate. TS measurements indicate electron temperature increases from ˜5 eV to ˜20 eV during 28 GHz power application when the neutral deuterium pressure is reduced below 0.13 Pa (˜1 mTorr.).

  15. Design and operation of 140 GHz gyrotron oscillators for power levels up to 1 MW CW

    Energy Technology Data Exchange (ETDEWEB)

    Jory, H.; Bier, R.; Craig, L.J.; Felch, K.; Ives, L.; Lopez, N.; Spang, S.

    1986-12-01

    Varian has designed and tested 140 GHz gyrotron oscillators that have generated output powers of 100 kW CW and 200 kW for 1 ms pulses. Upcoming tubes will be designed to operate at power levels of 200 kW CW and ultimately up to 1 MW CW. The important design considerations which are addressed in the higher power tubes include the design of the electron gun, interaction circuit, and output window. These issues will be discussed and the results of the earlier 140 GHz gyrotron work at Varian will be summarized.

  16. Design and operation of 140 GHz gyrotron oscillators for power levels up to 1 MW CW

    International Nuclear Information System (INIS)

    Jory, H.; Bier, R.; Craig, L.J.; Felch, K.; Ives, L.; Lopez, N.; Spang, S.

    1986-12-01

    Varian has designed and tested 140 GHz gyrotron oscillators that have generated output powers of 100 kW CW and 200 kW for 1 ms pulses. Upcoming tubes will be designed to operate at power levels of 200 kW CW and ultimately up to 1 MW CW. The important design considerations which are addressed in the higher power tubes include the design of the electron gun, interaction circuit, and output window. These issues will be discussed and the results of the earlier 140 GHz gyrotron work at Varian will be summarized

  17. Low cost low power 24 GHz FMCW radar transceiver for indoor presence detection

    NARCIS (Netherlands)

    Suijker, E.M.; Bolt, R.J.; Wanum, M. van; Heijningen, M. van; Maas, A.P.M.; Vliet, F.E. van

    2014-01-01

    In this paper a first time right 24 GHz FMCW radar transceiver is presented. The MMIC has a low power consumption of 86 mW and an output power of -10 dBm. Due to the integrated IF amplifier, the conversion gain of the receiver is 51 dB and the base band signals are directly processed with an ADC.

  18. CMOS 60-GHz and E-band power amplifiers and transmitters

    CERN Document Server

    Zhao, Dixian

    2015-01-01

    This book focuses on the development of design techniques and methodologies for 60-GHz and E-band power amplifiers and transmitters at device, circuit and layout levels. The authors show the recent development of millimeter-wave design techniques, especially of power amplifiers and transmitters, and presents novel design concepts, such as “power transistor layout” and “4-way parallel-series power combiner”, that can enhance the output power and efficiency of power amplifiers in a compact silicon area. Five state-of-the-art 60-GHz and E-band designs with measured results are demonstrated to prove the effectiveness of the design concepts and hands-on methodologies presented. This book serves as a valuable reference for circuit designers to develop millimeter-wave building blocks for future 5G applications.

  19. 75 GHz InP DHBT power amplifier based on two-stacked transistors

    DEFF Research Database (Denmark)

    Squartecchia, Michele; Midili, Virginio; Johansen, Tom Keinicke

    2017-01-01

    In this paper we present the design and measurements of a two-stage 75-GHz InP Double Heterojunction Bipolar Transistor (DHBT) power amplifier (PA). An optimized two-stacked transistor power cell has been designed, which represents the building block in the power stage as well as in the driver st......, the power amplifier exhibits a small signal gain of G = 12.6 dB, output power at 1-dB compression of Pout, 1dB = 18.6 dBm and a saturated output power of Psat > 21.4 dBm....

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

    International Nuclear Information System (INIS)

    Iannacci, J; Tschoban, C

    2017-01-01

    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. (paper)

  1. Ceramic Power Extractor Design at 15.6 GHz

    CERN Document Server

    Smirnov, Alexei Yu; Yi, Rong; Yu, David

    2005-01-01

    Power extractor and coupler designs developed for an experiment planned at the 12th beam harmonic of the upgraded Advanced Wakefield Accelerator (AWA) facility is described. New features are an upstream HOM dielectric damper with additional tapering, and a single-port coupler considered in two variants. Performance analysis includes coupler geometric tolerances, overvoltage, dipole mode wake and BBU; and wakefield losses induced in the damper.

  2. A low power and low phase-noise 91 96 GHz VCO in 90 nm CMOS

    Science.gov (United States)

    Lin, Yo-Sheng; Lan, Kai-Siang; Chuang, Ming-Yuan; Lin, Yu-Ching

    2018-06-01

    This paper reports a 94 GHz CMOS voltage-controlled oscillator (VCO) using both the negative capacitance (NC) technique and series-peaking output power and phase noise (PN) enhancement technique. NC is achieved by adding two variable LC networks to the source nodes of the active circuit of the VCO. NMOSFET varicaps are adopted as the required capacitors of the LC networks. In comparison with the conventional one, the proposed active circuit substantially decreases the input capacitance (Cin) to zero or even a negative value. This leads to operation (or oscillation) frequency (OF) increase and tuning range (TR) enhancement of the VCO. The VCO dissipates 8.3 mW at 1 V supply. The measured TR of the VCO is 91 96 GHz, close to the simulated (92.1 96.7 GHz) and the calculated one (92.2 98.2 GHz). In addition, at 1 MHz offset from 95.16 GHz, the VCO attains an excellent PN of - 98.3 dBc/Hz. This leads to a figure-of-merit (FOM) of -188.5 dBc/Hz, a remarkable result for a V- or W-band CMOS VCO. The chip size of the VCO is 0.75 × 0.42 mm2, i.e. 0.315 mm2.

  3. Construction and Testing of a 21 GHz Ceramic Based Power Extractor

    CERN Document Server

    Newsham, D; Carron, G; Döbert, Steffen; Gai, W; Konecny, R; Liu, W; Smirnov, A Yu; Thorndahl, L; Wilson, Ian H; Wuensch, Walter; Yu, D

    2003-01-01

    A ceramic based power extractor [1] operating at 21 GHz was built by DULY Research Inc. and tested at CTF2, the CERN Linear Collider (CLIC) Test Facility. The structure includes a ceramic extractor section, a 2-output-port, circular-to-rectangular waveguide coupler, and a 3-port rectangular waveguide combiner that provides for a single output waveguide. Results of cold tests and full beam tests are presented and compared with theoretical and numerical models.

  4. HIGH RESOLUTION 36 GHz IMAGING OF THE SUPERNOVA REMNANT OF SN 1987A

    International Nuclear Information System (INIS)

    Potter, T. M.; Staveley-Smith, L.; Zanardo, G.; Ng, C.-Y.; Gaensler, B. M.; Ball, Lewis; Kesteven, M. J.; Manchester, R. N.; Tzioumis, A. K.

    2009-01-01

    The aftermath of supernova (SN) 1987A continues to provide spectacular insights into the interaction between an SN blastwave and its circumstellar environment. We here present 36 GHz observations from the Australia Telescope Compact Array of the radio remnant of SN 1987A. These new images, taken in 2008 April and 2008 October, substantially extend the frequency range of an ongoing monitoring and imaging program conducted between 1.4 and 20 GHz. Our 36.2 GHz images have a diffraction-limited angular resolution of 0.''3-0.''4, which covers the gap between high resolution, low dynamic range VLBI images of the remnant and low resolution, high dynamic range images at frequencies between 1 and 20 GHz. The radio morphology of the remnant at 36 GHz is an elliptical ring with enhanced emission on the eastern and western sides, similar to that seen previously at lower frequencies. Model fits to the data in the Fourier domain show that the emitting region is consistent with a thick inclined torus of mean radius 0.''85, and a 2008 October flux density of 27 ± 6 mJy at 36.2 GHz. The spectral index for the remnant at this epoch, determined between 1.4 GHz and 36.2 GHz, is α = -0.83. There is tentative evidence for an unresolved central source with flatter spectral index.

  5. A low power 3-5 GHz CMOS UWB receiver front-end

    International Nuclear Information System (INIS)

    Li Weinan; Huang Yumei; Hong Zhiliang

    2009-01-01

    A novel low power RF receiver front-end for 3-5 GHz UWB is presented. Designed in the 0.13 μm CMOS process, the direct conversion receiver features a wideband balun-coupled noise cancelling transconductance input stage, followed by quadrature passive mixers and transimpedance loading amplifiers. Measurement results show that the receiver achieves an input return loss below -8.5 dB across the 3.1-4.7 GHz frequency range, maximum voltage conversion gain of 27 dB, minimum noise figure of 4 dB, IIP3 of -11.5 dBm, and IIP2 of 33 dBm. Working under 1.2 V supply voltage, the receiver consumes total current of 18 mA including 10 mA by on-chip quadrature LO signal generation and buffer circuits. The chip area with pads is 1.1 x 1.5 mm 2 .

  6. Remote powering platform for implantable sensor systems at 2.45 GHz.

    Science.gov (United States)

    Kazanc, Onur; Yilmaz, Gurkan; Maloberti, Franco; Dehollain, Catherine

    2014-01-01

    Far-field remotely powered sensor systems enable long distance operation for low-power sensor systems. In this work, we demonstrate a remote powering platform with a miniaturized antenna and remote powering base station operating at 2.45 GHz. The rectenna, which is the energy receiving and conversion element of the sensor system, is designed and measured. The measurements for the tag are performed within 15 cm distance from the remote powering base station. The realized gain of the tag antenna is measured as -3.3 dB, which is 0.5 dB close to the simulations, where simulated realized gain is -2.8 dB.

  7. Use of an untuned cavity for absolute power measurements of the harmonics above 100 GHz from an IMPATT oscillator

    Science.gov (United States)

    Llewellyn-Jones, D. T.; Knight, R. J.; Gebbie, H. A.

    1980-07-01

    A new technique of measuring absolute power exploiting an untuned cavity and Fourier spectroscopy has been used to examine the power spectrum of the harmonics and other overtones produced by a 95 GHz IMPATT oscillator. The conditions which favor the production of a rich harmonic spectrum are not those which maximize the fundamental power. Under some conditions of mismatch at the fundamental frequency it is possible to produce over 200 microW of harmonic power in the 100-200 GHz region comparable with the fundamental power from the oscillator.

  8. A 35 GHz wireless millimeter-wave power sensor based on GaAs micromachining technology

    International Nuclear Information System (INIS)

    Wang, De-bo; Liao, Xiao-ping

    2012-01-01

    A novel MEMS wireless millimeter-wave power sensor based on GaAs MMIC technology is presented in this paper. The principle of this wireless millimeter-wave power sensor is explained. It is designed and fabricated using MEMS technology and the GaAs MMIC process. With the millimeter-wave power range from 0.1 to 80 mW, the sensitivity of the wireless millimeter-wave power sensor is about 0.246 mV mW −1 at 35 GHz. In order to verify the power detection capability, this wireless power sensor is mounted on a PCB which influences the microwave performance of the CPW-fed antenna including the return loss and the radiation pattern. The frequency-dependent characteristic and the degree-dependent characteristic of this wireless power sensor are researched. Furthermore, in addition to the combination of the advantages of CPW-fed antenna with the advantages of the thermoelectric power sensor, another significant advantage of this wireless millimeter-wave power sensor is that it can be integrated with MMICs and other planar connecting circuit structures with zero dc power consumption. These features make it suitable for various applications ranging from the environment or space radiation detection systems to radar receiver and transmitter systems. (paper)

  9. 2.45 GHz Class E Power Amplifier for a Transmitter Combining LINC and EER

    Directory of Open Access Journals (Sweden)

    M. Dirix

    2009-01-01

    Full Text Available A 10 W class-E RF power amplifier (PA is designed and fabricated using a Cree GaN HEMT. The proposed PA uses an innovative input circuit to optimize band with. At 2.45 GHz the PA achieves a PAE of 60 % at an outputpower of 40 dBm. The resulting amplifier is simulated and constructed using a transmissionline topology. Two of these amplifiers are fabricated on a single board for outphasing application. Their suitability for outphasing application and supply modulation is investigated. 

  10. Cryogenic operation of a 24 GHz MMIC SiGe HBT medium power amplifier

    International Nuclear Information System (INIS)

    Qin, Guoxuan; Jiang, Ningyue; Seo, Jung-Hun; Cho, Namki; Van der Weide, Daniel; Ma, Zhenqiang; Ponchak, George E; Ma, Pingxi; Stetson, Scott; Racanelli, Marco

    2010-01-01

    The performance of a SiGe heterojunction bipolar transistor (HBT) millimetre-wave power amplifier (PA) operating at cryogenic temperature was reported and analysed for the first time. A 24 GHz two-stage medium PA employing common-emitter and common-base SiGe power HBTs in the first and the second stage, respectively, showed a significant power gain increase at 77 K in comparison with that measured at room temperature. Detailed analyses indicate that cryogenic operation of SiGe HBT-based PAs mainly affects (improves) the performance of the SiGe HBTs in the circuits due to transconductance enhancement through magnified, favourable changes of SiGe bandgap due to cooling (ΔE g /kT) and minimized thermal effects, with little influence on the passive components of the circuits

  11. Commissioning of the 28 GHz ECRH power transmission line for the TJ-II stellarator

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-Fernández, J., E-mail: jose.martinez@ciemat.es [Laboratorio Nacional de Fusión (LNF), Centro de Investigaciones Tecnológicas, Medioambientales y Tecnológicas (CIEMAT), Av/Complutense 40, 28040 Madrid (Spain); Cappa, Á. [Laboratorio Nacional de Fusión (LNF), Centro de Investigaciones Tecnológicas, Medioambientales y Tecnológicas (CIEMAT), Av/Complutense 40, 28040 Madrid (Spain); Chirkov, A. [Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod (Russian Federation); Ros, A.; Tolkachev, A.; Catalán, G.; Soleto, A.; Redondo, M. [Laboratorio Nacional de Fusión (LNF), Centro de Investigaciones Tecnológicas, Medioambientales y Tecnológicas (CIEMAT), Av/Complutense 40, 28040 Madrid (Spain); Doane, J.L.; Anderson, J.P. [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States)

    2015-10-15

    Highlights: • The 28 GHz power transmission line of the TJ-II stellarator is described. • Mismatch and alignment problems are covered, presenting infrared measurements. • Beam distortion in the matching optics unit led to unwanted modes in the waveguide. • After a redesign distortion was eliminated and coupling maximized. • Final measurements suggest finer alignment must be performed. - Abstract: The commissioning of the 28 GHz power transmission line of the TJ-II stellarator, designed for the excitation of electron Bernstein waves (EBW) through the O-X-B mode conversion process, is presented in this paper. Based upon a comprehensive set of thermal measurements, its purpose is to go into details about the several problems that arouse during the whole process, namely higher order modes excitation because of the wider beam size and alignment mismatches at the waveguide mouth. All these drawbacks may have prevented the correct O-X mode conversion, thus providing a reasonable explanation for the unsuccessful EBW heating experiments.

  12. A low-power 802.11 AD compatible 60-GHz phase-locked loop in 65-NM CMOS

    KAUST Repository

    Cheema, Hammad M.; Arsalan, Muhammad; Salama, Khaled N.; Shamim, Atif

    2015-01-01

    A 60-GHz fundamental frequency phase locked loop (PLL) as part of a highly integrated system-on-chip transmitter with onchip memory and antenna is presented. As a result of localized optimization approach for each component, the PLL core components only consume 30.2 mW from a 1.2 V supply. A systematic design procedure to achieve high phase margin and wide locking range is presented. The reduction of parasitic and fixed capacitance contributions in the voltage controlled oscillator enables the coverage of the complete 802.11 ad frequency band from 57.2 to 65.8 GHz. A new 4-stage distribution network supplying the local oscillator (LO) signal to the mixer, the feedback loop and the external equipment is introduced. The prescaler based on the static frequency division approach is enhanced using shunt-peaking and asymmetric capacitive loading. The current mode logic based divider chain is optimized for low power and minimum silicon foot-print. A dead-zone free phase frequency detector, low leakage charge pump, and an integrated second-order passive filter completes the feedback loop. The PLL implemented in 65 nm CMOS process occupies only 0.6 mm2 of chip space and has a measured locking range from 56.8 to 66.5 GHz. The reference spurs are lower than -40 dBc and the in-band and out-of-band phase noise is -88.12 dBc/Hz and -117 dBc/Hz, respectively.

  13. A low-power 802.11 AD compatible 60-GHz phase-locked loop in 65-NM CMOS

    KAUST Repository

    Cheema, Hammad M.

    2015-01-23

    A 60-GHz fundamental frequency phase locked loop (PLL) as part of a highly integrated system-on-chip transmitter with onchip memory and antenna is presented. As a result of localized optimization approach for each component, the PLL core components only consume 30.2 mW from a 1.2 V supply. A systematic design procedure to achieve high phase margin and wide locking range is presented. The reduction of parasitic and fixed capacitance contributions in the voltage controlled oscillator enables the coverage of the complete 802.11 ad frequency band from 57.2 to 65.8 GHz. A new 4-stage distribution network supplying the local oscillator (LO) signal to the mixer, the feedback loop and the external equipment is introduced. The prescaler based on the static frequency division approach is enhanced using shunt-peaking and asymmetric capacitive loading. The current mode logic based divider chain is optimized for low power and minimum silicon foot-print. A dead-zone free phase frequency detector, low leakage charge pump, and an integrated second-order passive filter completes the feedback loop. The PLL implemented in 65 nm CMOS process occupies only 0.6 mm2 of chip space and has a measured locking range from 56.8 to 66.5 GHz. The reference spurs are lower than -40 dBc and the in-band and out-of-band phase noise is -88.12 dBc/Hz and -117 dBc/Hz, respectively.

  14. 94 GHz power amplifier MMIC development in state of the art MHEMT and AlGaN/GaN technology

    NARCIS (Netherlands)

    Heijningen, M. van; Bent, G. van der; Rodenburg, M.; Vliet, F.E. van; Quay, R.; Brückner, P.; Schwantuschke, D.; Jukkala, P.; Narhi, T.

    2012-01-01

    Solid-state power amplifiers at W-band (75 - 110 GHz) are attractive for the generation of local-oscillator (LO) power for super-heterodyne receivers operating at sub-millimetre wave frequencies, as needed for example in future space instruments for Earth observation. Apart from space applications

  15. High-gradient electron accelerator powered by a relativisitic klystron

    International Nuclear Information System (INIS)

    Allen, M.A.; Boyd, J.K.; Callin, R.S.; Deruyter, H.; Eppley, K.R.; Fant, K.S.; Fowkes, W.R.; Haimson, J.; Hoag, H.A.; Hopkins, D.B.; Houck, T.; Koontz, R.F.; Lavine, T.L.; Loew, G.A.; Mecklenburg, B.; Miller, R.H.; Ruth, R.D.; Ryne, R.D.; Sessler, A.M.; Vlieks, A.E.; Wang, J.W.; Westenskow, G.A.; Yu, S.S.

    1989-01-01

    We have used relativistic klystron technology to extract 290 MW of peak power at 11.4 GHz from an induction linac beam, and to power a short 11.4-GHz high-gradient accelerator. We have measured rf phase stability, field emission, and the momentum spectrum of an accelerated electron beam. An average accelerating gradient of 84 MV/m has been achieved with 80 MW of relativistic klystron power

  16. A low power 2.4 GHz transceiver for ZigBee applications

    International Nuclear Information System (INIS)

    Liu Weiyang; Chen Jingjing; Wang Haiyong; Wu Nanjian

    2013-01-01

    This paper presents a low power 2.4 GHz transceiver for ZigBee applications. This transceiver adopts low power system architecture with a low-IF receiver and a direct-conversion transmitter. The receiver consists of a new low noise amplifier (LNA) with a noise cancellation function, a new inverter-based variable gain complex filter (VGCF) for image rejection, a passive quadrature mixer, and a decibel linear programmable gain amplifier (PGA). The transmitter adopts a quadrature mixer and a class-B mode variable gain power amplifier (PA) to reduce power consumption. This transceiver is implemented in 0.18 μm CMOS technology. The receiver achieves −95 dBm of sensitivity, 28 dBc of image rejection, and −8 dBm of third-order input intercept point (IIP3). The transmitter can deliver a maximum of +3 dBm output power with PA efficiency of 30%. The whole chip area is less than 4.32 mm 2 . It only consumes 12.63 mW in receiving mode and 14.22 mW in transmitting mode, respectively. (semiconductor integrated circuits)

  17. Linearizing of Low Noise Power Amplifier Using 5.8GHz Double Loop Feedforward Linearization Technique

    Directory of Open Access Journals (Sweden)

    Abdulkareem Mokif Obais

    2017-05-01

    Full Text Available In this paper, a double loop feedforward linearization technique is analyzed and built with a MMIC low noise amplifier “HMC753” as main amplifier and a two-stage class-A power amplifier as error amplifier. The system is operated with 5V DC supply at a center frequency of 5.8GHz and a bandwidth of 500MHz. The proposed technique, increases the linearity of the MMIC amplifier from 18dBm at 1dB compression point to more than 26dBm. In addition, the proposed system is tested with OFDM signal and it reveals good response in maximizing the linearity region and eliminating distortions. The proposed system is designed and simulated onAdvanced Wave Research-Microwave Office (AWR-MWO.

  18. A Low Power 2.4 GHz CMOS Mixer Using Forward Body Bias Technique for Wireless Sensor Network

    Science.gov (United States)

    Yin, C. J.; Murad, S. A. Z.; Harun, A.; Ramli, M. M.; Zulkifli, T. Z. A.; Karim, J.

    2018-03-01

    Wireless sensor network (WSN) is a highly-demanded application since the evolution of wireless generation which is often used in recent communication technology. A radio frequency (RF) transceiver in WSN should have a low power consumption to support long operating times of mobile devices. A down-conversion mixer is responsible for frequency translation in a receiver. By operating a down-conversion mixer at a low supply voltage, the power consumed by WSN receiver can be greatly reduced. This paper presents a development of low power CMOS mixer using forward body bias technique for wireless sensor network. The proposed mixer is implemented using CMOS 0.13 μm Silterra technology. The forward body bias technique is adopted to obtain low power consumption. The simulation results indicate that a low power consumption of 0.91 mW is achieved at 1.6 V supply voltage. Moreover, the conversion gain (CG) of 21.83 dB, the noise figure (NF) of 16.51 dB and the input-referred third-order intercept point (IIP3) of 8.0 dB at 2.4 GHz are obtained. The proposed mixer is suitable for wireless sensor network.

  19. Circuit design and simulation of a HV-supply controlling the power of 140 GHz 1 MW gyrotrons for ECRH on W7-X

    International Nuclear Information System (INIS)

    Brand, P.; Mueller, G.A.

    2003-01-01

    For plasma heating by ECR in the Stellarator W7-X under construction, 140 GHz gyrotrons with 1 MW cw output power are under development. These tubes have a voltage depressed collector for electron energy recovery. Each gyrotron is fed by two high-voltage sources: a high-power supply for driving the electron beam and a precision low-power supply for beam acceleration. In addition, a protection system with a thyratron crowbar for fast power removal in case of gyrotron arcing is installed. The low-power high-voltage source for beam acceleration is realized by a high-voltage servo-amplifier driving the depression voltage such that the influence of the voltage noise of the main high-power supply on the acceleration voltage is suppressed by feed-back control of the amplifier. Design and simulation of the servo-amplifier by PSpice is presented

  20. Polarization sensitive detection of 100 GHz radiation by high mobility field-effect transistors

    International Nuclear Information System (INIS)

    Sakowicz, M.; Lusakowski, J.; Karpierz, K.; Grynberg, M.; Knap, W.; Gwarek, W.

    2008-01-01

    Detection of 100 GHz electromagnetic radiation by a GaAs/AlGaAs high electron mobility field-effect transistor was investigated at 300 K as a function of the angle α between the direction of linear polarization of the radiation and the symmetry axis of the transistor. The angular dependence of the detected signal was found to be A 0 cos 2 (α-α 0 )+C with A 0 , α 0 , and C dependent on the electrical polarization of the transistor gate. This dependence is interpreted as due to excitation of two crossed phase-shifted oscillators. A response of the transistor chip (including bonding wires and the substrate) to 100 GHz radiation was numerically simulated. Results of calculations confirmed experimentally observed dependencies and showed that the two oscillators result from an interplay of 100 GHz currents defined by the transistor impedance together with bonding wires and substrate related modes

  1. High capacity hybrid optical fiber-wireless links in 75–300GHz band

    DEFF Research Database (Denmark)

    Cavalcante, Lucas Costa Pereira; Vegas Olmos, Juan José; Tafur Monroy, Idelfonso

    2014-01-01

    Seamless convergence of fiber-optic and the wireless networks is of great interest for enabling transparent delivery of broadband services to users in different locations, including both metropolitan and rural areas. Current demand of bandwidth by end-users, especially using mobile devices......, is seeding the need to use bands located at the millimeter-wave region (30–300 GHz), mainly because of its inherent broadband nature. In our lab, we have conducted extensive research on high-speed photonic-wireless links in the W-band (75–110GHz). In this paper, we will present our latest findings...

  2. Sub-GHz-resolution C-band Nyquist-filtering interleaver on a high-index-contrast photonic integrated circuit.

    Science.gov (United States)

    Zhuang, Leimeng; Zhu, Chen; Corcoran, Bill; Burla, Maurizio; Roeloffzen, Chris G H; Leinse, Arne; Schröder, Jochen; Lowery, Arthur J

    2016-03-21

    Modern optical communications rely on high-resolution, high-bandwidth filtering to maximize the data-carrying capacity of fiber-optic networks. Such filtering typically requires high-speed, power-hungry digital processes in the electrical domain. Passive optical filters currently provide high bandwidths with low power consumption, but at the expense of resolution. Here, we present a passive filter chip that functions as an optical Nyquist-filtering interleaver featuring sub-GHz resolution and a near-rectangular passband with 8% roll-off. This performance is highly promising for high-spectral-efficiency Nyquist wavelength division multiplexed (N-WDM) optical super-channels. The chip provides a simple two-ring-resonator-assisted Mach-Zehnder interferometer, which has a sub-cm2 footprint owing to the high-index-contrast Si3N4/SiO2 waveguide, while manifests low wavelength-dependency enabling C-band (> 4 THz) coverage with more than 160 effective free spectral ranges of 25 GHz. This device is anticipated to be a critical building block for spectrally-efficient, chip-scale transceivers and ROADMs for N-WDM super-channels in next-generation optical communication networks.

  3. High-performance CPW MMIC LNA using GaAs-based metamorphic HEMTs for 94-GHz applications

    International Nuclear Information System (INIS)

    Ryu, Keun-Kwan; Kim, Sung-Chan; An, Dan; Rhee, Jin-Koo

    2010-01-01

    In this paper, we report on a high-performance low-noise amplifier (LNA) using metamorphic high-electron-mobility transistor (MHEMT) technology for 94-GHz applications. The 100 nm x 60 μm MHEMT devices for the coplanar MMIC LNA exhibited DC characteristics with a drain current density of 655 mA/mm and an extrinsic transconductance of 720 mS/mm. The current gain cutoff frequency (f T ) and the maximum oscillation frequency (f max ) were 195 GHz and 305 GHz, respectively. Based on this MHEMT technology, coplanar 94-GHz MMIC LNAs were realized, achieving a small signal gain of more than 13 dB between 90 and 100 GHz and a small signal gain of 14.8 dB and a noise figure of 4.7 dB at 94 GHz.

  4. Demonstration of a High-Order Mode Input Coupler for a 220-GHz Confocal Gyrotron Traveling Wave Tube

    Science.gov (United States)

    Guan, Xiaotong; Fu, Wenjie; Yan, Yang

    2018-02-01

    A design of high-order mode input coupler for 220-GHz confocal gyrotron travelling wave tube is proposed, simulated, and demonstrated by experimental tests. This input coupler is designed to excite confocal TE 06 mode from rectangle waveguide TE 10 mode over a broadband frequency range. Simulation results predict that the optimized conversion loss is about 2.72 dB with a mode purity excess of 99%. Considering of the gyrotron interaction theory, an effective bandwidth of 5 GHz is obtained, in which the beam-wave coupling efficiency is higher than half of maximum. The field pattern under low power demonstrates that TE 06 mode is successfully excited in confocal waveguide at 220 GHz. Cold test results from the vector network analyzer perform good agreements with simulation results. Both simulation and experimental results illustrate that the reflection at input port S11 is sensitive to the perpendicular separation of two mirrors. It provides an engineering possibility for estimating the assembly precision.

  5. A 3 GHz photoelectron gun for high beam intensity

    CERN Document Server

    Bossart, Rudolf; Dehler, M; Godot, J C

    1996-01-01

    For the Compact Linear Collider Test Facility (CTF) at CERN a new rf gun with a laser driven photocathode is under construction. The new rf gun will replace the present 11/2 cell gun and will consist of 21/2 cells accelerating the beam to a momentum of 7.0 MeV/c with an electric field strength of 100 MV/m. The strong space-charge forces at low beam energy caused by the high charge density of the electron bunches are contained by radial and longitudinal rf focusing in the gun. The rf gun under construction has been optimized by MAFIA beam simulations for an injector assembly comprising a second accelerating rf structure and an intermediate solenoid magnet correcting the beam divergence of the 21/2 cell gun. The beam loading of the rf gun, by a train of 48 bunches with 21 nC charge each, causes a strong energy decay accompanied by an increase of the flight time for the bunches with lower energy. These effects can be corrected by slightly shifting the acceleration frequency of the gun. The experimental results...

  6. 10 GHz frequency comb spectral broadening in AlGaAs-on-Insulator nano-waveguide with ultra-low pump power

    DEFF Research Database (Denmark)

    Hu, Hao; Pu, Minhao; Yvind, Kresten

    2017-01-01

    We experimentally demonstrated 10 GHz frequency comb spectral broadening with a 30-dB bandwidth of 238 nm in an 11-mm long AlGaAsOI nano-waveguide. The 10-GHz 230-fs pump pulse has an average power of only 12 mW.......We experimentally demonstrated 10 GHz frequency comb spectral broadening with a 30-dB bandwidth of 238 nm in an 11-mm long AlGaAsOI nano-waveguide. The 10-GHz 230-fs pump pulse has an average power of only 12 mW....

  7. High field Q slope and the effect of low-temperature baking at 3 GHz

    Science.gov (United States)

    Ciovati, G.; Eremeev, G.; Hannon, F.

    2018-01-01

    A strong degradation of the unloaded quality factor with field, called high field Q slope, is commonly observed above Bp ≅100 mT in elliptical superconducting niobium cavities at 1.3 and 1.5 GHz. In the present experiments several 3 GHz niobium cavities were measured up to and above Bp ≅100 mT . The measurements show that a high field Q slope phenomenon limits the field reach at this frequency, that the high field Q slope onset field depends weakly on the frequency, and that the high field Q slope can be removed by the typical empirical solution of electropolishing followed by heating to 120°C for 48 hrs. In addition, one of the cavities reached a quench field of 174 mT and its field dependence of the quality factor was compared against global heating predicted by a thermal feedback model.

  8. High-Frequency Wireless Communications System: 2.45-GHz Front-End Circuit and System Integration

    Science.gov (United States)

    Chen, M.-H.; Huang, M.-C.; Ting, Y.-C.; Chen, H.-H.; Li, T.-L.

    2010-01-01

    In this article, a course on high-frequency wireless communications systems is presented. With the 145-MHz baseband subsystem available from a prerequisite course, the present course emphasizes the design and implementation of the 2.45-GHz front-end subsystem as well as system integration issues. In this curriculum, the 2.45-GHz front-end…

  9. Development of 20 kW input power coupler for 1.3 GHz ERL main linac. Component test at 30 kW IOT test stand

    International Nuclear Information System (INIS)

    Sakai, Hiroshi; Umemori, Kensei; Sakanaka, Shogo; Takahashi, Takeshi; Furuya, Takaaki; Shinoe, Kenji; Ishii, Atsushi; Nakamura, Norio; Sawamura, Masaru

    2009-01-01

    We started to develop an input coupler for a 1.3 GHz ERL superconducting cavity. Required input power is about 20 kW for the cavity acceleration field of 20 MV/m and the beam current of 100 mA in energy recovery operation. The input coupler is designed based on the STF-BL input coupler and some modifications are applied to the design for the CW 20 kW power operation. We fabricated input coupler components such as ceramic windows and bellows and carried out the high-power test of the components by using a 30 kW IOT power source and a test stand constructed for the highpower test. In this report, we mainly describe the results of the high-power test of ceramic window and bellows. (author)

  10. Experimental studies of 2.45 GHz ECR ion sources for the production of high intensity currents

    International Nuclear Information System (INIS)

    Coly, A.

    2010-12-01

    This thesis is the result of a collaboration between the Pantechnik company and the LPSC (Laboratory of subatomic physics and cosmology of Grenoble). It consisted in the development of a new test bench dedicated to the characterization of a 2.45 GHz ECR ion sources with the aim of the production of high currents beams for industrial purposes. Two ECR ions sources with different magnetic structures have been tested around the same RF injection system. A new 2.45 GHz ECRIS, named SPEED, featuring a dipolar magnetic field at the extraction has been designed and tested. A study of the beam extraction in the dipolar magnetic field is proposed. First tests have shown a total ionic current density of about 10 mA/cm 2 with a 900 W RF power. Tests with hydrogen plasma have shown a maximum of current on the H 2 + species. Recommendations are given to modify the magnetic structure to improve the H + production yield. The MONO1000 ion source has been tested at high RF power with a wave guide type injection system. Intense total ionic current densities have been measured up to about 95 mA/cm 2 with a diode extraction system. First results using an improved 5 electrode extraction system are presented. (author)

  11. 3-D printed 2.4 GHz rectifying antenna for wireless power transfer applications

    Science.gov (United States)

    Skinner, Matthew

    In this work, a 3D printed rectifying antenna that operates at the 2.4GHz WiFi band was designed and manufactured. The printed material did not have the same properties of bulk material, so the printed materials needed to be characterized. The antenna and rectifying circuit was printed out of Acrylonitrile Butadiene Styrene (ABS) filament and a conductive silver paste, with electrical components integrated into the circuit. Before printing the full rectifying antenna, each component was printed and evaluated. The printed antenna operated at the desired frequency with a return loss of -16 dBm with a bandwidth of 70MHz. The radiation pattern was measured in an anechoic chamber with good matching to the model. The rectifying circuit was designed in Ansys Circuit Simulation using Schottky diodes to enable the circuit to operate at lower input power levels. Two rectifying circuits were manufactured, one by printing the conductive traces with silver ink, and one with traces made from copper. The printed silver ink is less conductive than the bulk copper and therefore the output voltage of the printed rectifier was lower than the copper circuit. The copper circuit had an efficiency of 60% at 0dBm and the printed silver circuit had an efficiency of 28.6% at 0dBm. The antenna and rectifying circuits were then connected to each other and the performance was compared to a fully printed integrated rectifying antenna. The rectifying antennas were placed in front of a horn antenna while changing the power levels at the antenna. The efficiency of the whole system was lower than the individual components but an efficiency of 11% at 10dBm was measured.

  12. Analogue demonstration of a high temperature superconducting sigma-delta modulator with 27 GHz sampling

    Energy Technology Data Exchange (ETDEWEB)

    Forrester, M.G.; Hunt, B.D.; Miller, D.L.; Talvacchio, J.; Young, R.M. [Northrop Grumman Science and Technology Center, Pittsburgh, PA 15235-5098 (United States)

    1999-11-01

    We have successfully fabricated and tested a high temperature superconducting (HTS) sigma-delta modulator for analogue-to-digital conversion. This is the first demonstration of a GHz sampling A-to-D in HTS. The 15-junction single-flux-quantum (SFQ) circuit, fabricated using an epitaxial multilayer HTS process with YBCO/Co-YBCO/YBCO edge junctions, was internally clocked at 27 GHz and used to convert a 5.01 MHz signal. The modulator demonstrated a spur-free dynamic range of more than 75 dB. Two-tone measurements with 5.01 MHz and 5.51 MHz signals demonstrated third-order intermodulation products to be lower than -59 dBc. Demonstration of a functional HTS modulator represents a significant milestone in the development of high dynamic range ADCs suitable for such applications as surveillance radar. (author)

  13. Design of low power common-gate low noise amplifier for 2.4 GHz wireless sensor network applications

    International Nuclear Information System (INIS)

    Zhang Meng; Li Zhiqun

    2012-01-01

    This paper presents a differential low power low noise amplifier designed for the wireless sensor network (WSN) in a TSMC 0.18 μm RF CMOS process. A two-stage cross-coupling cascaded common-gate (CG) topology has been designed as the amplifier. The first stage is a capacitive cross-coupling topology. It can reduce the power and noise simultaneously. The second stage is a positive feedback cross-coupling topology, used to set up a negative resistance to enhance the equivalent Q factor of the inductor at the load to improve the gain of the LNA. A differential inductor has been designed as the load to achieve reasonable gain. This inductor has been simulated by the means of momentum electromagnetic simulation in ADS. A 'π' circuit model has been built as the inductor model by iteration in ADS. The inductor has been fabricated separately to verify the model. The LNA has been fabricated and measured. The LNA works well centered at 2.44 GHz. The measured gain S 21 is variable with high gain at 16.8 dB and low gain at 1 dB. The NF (noise figure) at high gain mode is 3.6 dB, the input referenced 1 dB compression point (IP1dB) is about −8 dBm and the IIP3 is 2 dBm at low gain mode. The LNA consumes about 1.2 mA current from 1.8 V power supply.

  14. Four-to-one power combiner for 20 GHz phased array antenna using RADC MMIC phase shifters

    Science.gov (United States)

    1991-01-01

    The design and microwave simulation of two-to-one microstrip power combiners is described. The power combiners were designed for use in a four element phase array receive antenna subarray at 20 GHz. Four test circuits are described which were designed to enable testing of the power combiner and the four element phased array antenna. Test Circuit 1 enables measurement of the two-to-one power combiner. Test Circuit 2 enables measurement of the four-to-one power combiner. Test Circuit 3 enables measurement of a four element antenna array without phase shifting MMIC's in order to characterize the power combiner with the antenna patch-to-microstrip coaxial feedthroughs. Test circuit 4 is the four element phased array antenna including the RADC MMIC phase shifters and appropriate interconnects to provide bias voltages and control phase bits.

  15. An Optimized 2.4GHz RF Power Amplifier Performance for WLAN System

    International Nuclear Information System (INIS)

    Ali, Mohammed H; Chakrabarty, C K; Hock, Goh C; Abdalla, Ahmed N

    2013-01-01

    Recently, the design of RF power amplifiers (PAs) for modern wireless systems are faced with a difficult tradeoff for example, cellphone; battery lifetime is largely determined by the power efficiency of the PA and high spectral efficiency which have ability to transmit data at the highest possible rate for a given channel bandwidth. This paper presents the design a multi stage class AB power Amplifier with high power added efficiency (PAE) and acceptable linearity for the WLAN applications. The open-circuited third harmonic control circuit enhances the efficiency of the PA without deteriorating the linearity of class-AB mode of the PA. The voltage and current waveforms are simulated to evaluate the appropriate operation for the modes. The effectiveness of the proposed controller has been verified by comparing proposed method with another methods using simulation study under a variety of conditions. The proposed circuit operation for a WLAN signals delivers a power-added efficiency (PAE) of 37.6% is measured at 31.6-dBm output power while dissipating 34.61 mA from a 1.8V supply. Finally, the proposed PA is show a good and acceptable result for the WLAN system.

  16. An Optimized 2.4GHz RF Power Amplifier Performance for WLAN System

    Science.gov (United States)

    Ali, Mohammed H.; Chakrabarty, C. K.; Abdalla, Ahmed N.; Hock, Goh C.

    2013-06-01

    Recently, the design of RF power amplifiers (PAs) for modern wireless systems are faced with a difficult tradeoff for example, cellphone; battery lifetime is largely determined by the power efficiency of the PA and high spectral efficiency which have ability to transmit data at the highest possible rate for a given channel bandwidth. This paper presents the design a multi stage class AB power Amplifier with high power added efficiency (PAE) and acceptable linearity for the WLAN applications. The open-circuited third harmonic control circuit enhances the efficiency of the PA without deteriorating the linearity of class-AB mode of the PA. The voltage and current waveforms are simulated to evaluate the appropriate operation for the modes. The effectiveness of the proposed controller has been verified by comparing proposed method with another methods using simulation study under a variety of conditions. The proposed circuit operation for a WLAN signals delivers a power-added efficiency (PAE) of 37.6% is measured at 31.6-dBm output power while dissipating 34.61 mA from a 1.8V supply. Finally, the proposed PA is show a good and acceptable result for the WLAN system.

  17. Novel miniature high power ring filter

    International Nuclear Information System (INIS)

    Huang Huifen; Mao Junfa; Luo Zhihua

    2005-01-01

    The power handling capability of high temperature superconducting (HTS) filters is limited due to current concentration at the edges of the superconducting films. This problem can be overcome by using ring resonator, which employs the edge current free and reduces the current concentration. However, this kind of filter has large size. In order to reduce the cost and size and increase the power handling capability, in this paper a HTS photonic bandgap (PBG) structure filter is developed. The proposed pass band filter with PBG structure exhibits center frequency 12.23 GHz, steepness (about 35 dB/GHz), bandwidth (-3 dB bandwidth is 0.045 GHz), and low insertion loss (about -0.5 dB), and can handle input power up to 1 W (this value was limited by the measurement instrument used in the experiment). The size is reduced by 25%, insertion loss reduced by 37.5%, and steeper roll-off of the filter is also obtained compared with that in published literature

  18. 110GHz ECH on DIII-D

    International Nuclear Information System (INIS)

    Cary, W.P.; Allen, J.C.; Callis, R.W.; Doane, J.L.; Harris, T.E.; Moetler, C.P.; Neren, A.; Prater, P.; Rensen, D.

    1992-01-01

    This paper reports on a new high power electron cyclotron heating (ECH) system which has been introduced on DIII-D. This system is designed to operate at 110 GHz with a total output power of 2 MW. The system consists of four Varian VGT-8011 gyrotrons (output power of 500 kW), and their associated support equipment. All components have been designed for up to a 10 second pulse duration. The 110 GHz system is intended to further progress in rf current drive experiments on DIII-D when used in conjunction with the existing 60 GHz ECH (1. 6 MW) , and the 30-60 MHz ICH (2MW) systems. H-mode physics, plasma stabilization experiments and transport studies are also to be conducted at 110 GHz

  19. Measurements of the temporal and spatial phase variations of a 33 GHz pulsed free electron laser amplifier and application to high gradient RF acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Volfbeyn, P.; Bekefi, G. [Massachusetts Institute of Technology, Cambridge, MA (United States)

    1995-12-31

    We report the results of temporal and spatial measurements of phase of a pulsed free electron laser amplifier (FEL) operating in combined wiggler and axial guide magnetic fields. The 33 GHz FEL is driven by a mildly relativistic electron beam (750 kV, 90-300 A, 30 ns) and generates 61 MW of radiation with a high power magnetron as the input source. The phase is measured by an interferometric technique from which frequency shifting is determined. The results are simulated with a computer code. Experimental studies on a CERN-CLIC 32.98 GHz 26-cell high gradient accelerating section (HGA) were carried out for input powers from 0.1 MW to 35 MW. The FEL served as the r.f. power source for the HGA. The maximum power in the transmitted pulse was measured to be 15 MW for an input pulse of 35 MW. The theoretically calculated shunt impedance of 116 M{Omega}/m predicts a field gradient of 65 MeV/m inside the HGA. For power levels >3MW the pulse transmitted through the HGA was observed to be shorter than the input pulse and pulse shortening became more serious with increasing power input. At the highest power levels the output pulse length (about 5 nsec) was about one quarter of the input pulse length. Various tests suggest that these undesirable effects occur in the input coupler to the HGA. Light and X-ray production inside the HGA have been observed.

  20. Free electron laser with small period wiggler and sheet electron beam: A study of the feasibility of operation at 300 GHz with 1 MW CW output power

    International Nuclear Information System (INIS)

    Booske, J.H.; Granatstein, V.L.; Antonsen, T.M. Jr.

    1988-01-01

    The use of a small period wiggler (/ell//sub ω/ 2 ). Based on these encouraging results, a proof-of-principle experiment is being assembled, and is aimed at demonstrating FEL operating at 120 GHz with 300 kW output power in 1 μs pulses: electron energy would be 410 keV. Preliminary design of a 300 GHz 1 MW FEL with an untapered wiggler is also presented. 10 refs., 5 figs., 3 tabs

  1. Power-Combined GaN Amplifier with 2.28-W Output Power at 87 GHz

    Science.gov (United States)

    Fung, King Man; Ward, John; Chattopadhyay, Goutam; Lin, Robert H.; Samoska, Lorene A.; Kangaslahti, Pekka P.; Mehdi, Imran; Lambrigtsen, Bjorn H.; Goldsmith, Paul F.; Soria, Mary M.; hide

    2011-01-01

    Future remote sensing instruments will require focal plane spectrometer arrays with higher resolution at high frequencies. One of the major components of spectrometers are the local oscillator (LO) signal sources that are used to drive mixers to down-convert received radio-frequency (RF) signals to intermediate frequencies (IFs) for analysis. By advancing LO technology through increasing output power and efficiency, and reducing component size, these advances will improve performance and simplify architecture of spectrometer array systems. W-band power amplifiers (PAs) are an essential element of current frequency-multiplied submillimeter-wave LO signal sources. This work utilizes GaN monolithic millimeter-wave integrated circuit (MMIC) PAs developed from a new HRL Laboratories LLC 0.15- m gate length GaN semiconductor transistor. By additionally waveguide power combining PA MMIC modules, the researchers here target the highest output power performance and efficiency in the smallest volume achievable for W-band.

  2. Strategic Control of 60 GHz Millimeter-Wave High-Speed Wireless Links for Distributed Virtual Reality Platforms

    Directory of Open Access Journals (Sweden)

    Joongheon Kim

    2017-01-01

    Full Text Available This paper discusses the stochastic and strategic control of 60 GHz millimeter-wave (mmWave wireless transmission for distributed and mobile virtual reality (VR applications. In VR scenarios, establishing wireless connection between VR data-center (called VR server (VRS and head-mounted VR device (called VRD allows various mobile services. Consequently, utilizing wireless technologies is obviously beneficial in VR applications. In order to transmit massive VR data, the 60 GHz mmWave wireless technology is considered in this research. However, transmitting the maximum amount of data introduces maximum power consumption in transceivers. Therefore, this paper proposes a dynamic/adaptive algorithm that can control the power allocation in the 60 GHz mmWave transceivers. The proposed algorithm dynamically controls the power allocation in order to achieve time-average energy-efficiency for VR data transmission over 60 GHz mmWave channels while preserving queue stabilization. The simulation results show that the proposed algorithm presents desired performance.

  3. 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)

  4. Broadband rectangular TEn0 mode exciter with H-plane power dividers for 100 GHz confocal gyro-devices.

    Science.gov (United States)

    Yao, Yelei; Wang, Jianxun; Li, Hao; Liu, Guo; Luo, Yong

    2017-07-01

    A generic approach to excite TE n0 (n ≥ 1) modes in a rectangular waveguide for confocal gyro-devices is proposed. The exciter consists of a 3 dB H-plane power divider (n ≥ 3) and a mode-converting section. The injection power is split into two in-phase signals with equal amplitudes which simultaneously excite the secondary waveguide via two sets of multiple slots. Both the position and width of the slot are symmetrically distributed with respect to the center line for each set of slots. The slot width complies with a geometry sequence, with adjacent slots being spaced a quarter wavelength apart to cancel the backward wave out. A TE 40 mode exciter at 100 GHz is numerically simulated and optimized, achieving a 1 dB and a 3 dB transmission bandwidth of 18.2 and 21 GHz, respectively. The prototype is fabricated and measured. The cold test is carried out utilizing two identical back-to-back connected mode exciters, and the measured performances are in good agreement with the numerical simulation results when taking into account the wall loss and assembly tolerance.

  5. High sensitivity broadband 360GHz passive receiver for TeraSCREEN

    Science.gov (United States)

    Wang, Hui; Oldfield, Matthew; Maestrojuán, Itziar; Platt, Duncan; Brewster, Nick; Viegas, Colin; Alderman, Byron; Ellison, Brian N.

    2016-05-01

    TeraSCREEN is an EU FP7 Security project aimed at developing a combined active, with frequency channel centered at 360 GHz, and passive, with frequency channels centered at 94, 220 and 360 GHz, imaging system for border controls in airport and commercial ferry ports. The system will include automatic threat detection and classification and has been designed with a strong focus on the ethical, legal and practical aspects of operating in these environments and with the potential threats in mind. Furthermore, both the passive and active systems are based on array receivers with the active system consisting of a 16 element MIMO FMCW radar centered at 360 GHz with a bandwidth of 30 GHz utilizing a custom made direct digital synthesizer. The 16 element passive receiver system at 360 GHz uses commercial Gunn diode oscillators at 90 GHz followed by custom made 90 to 180 GHz frequency doublers supplying the local oscillator for 360 GHz sub-harmonic mixers. This paper describes the development of the passive antenna module, local oscillator chain, frequency mixers and detectors used in the passive receiver array of this system. The complete passive receiver chain is characterized in this paper.

  6. CSTI High Capacity Power

    International Nuclear Information System (INIS)

    Winter, J.M.

    1989-01-01

    The SP-100 program was established in 1983 by DOD, DOE, and NASA as a joint program to develop the technology necessary for space nuclear power systems for military and civil application. During FY-86 and 87, the NASA SP-100 Advanced Technology Program was devised to maintain the momentum of promising technology advancement efforts started during Phase 1 of SP-100 and to strengthen, in key areas, the chances for successful development and growth capability of space nuclear reactor power systems for future space applications. In FY-88, the Advanced Technology Program was incorporated into NASA's new Civil Space Technology Initiative (CSTI). The CSTI Program was established to provide the foundation for technology development in automation and robotics, information, propulsion, and power. The CSTI High Capacity Power Program builds on the technology efforts of the SP-100 program, incorporates the previous NASA SP-100 Advanced Technology project, and provides a bridge to NASA Project Pathfinder. The elements of CSTI High Capacity Power development include Conversion Systems, Thermal Management, Power Management, System Diagnostics, and Environmental Interactions. Technology advancement in all areas, including materials, is required to assure the high reliability and 7 to 10 year lifetime demanded for future space nuclear power systems. The overall program will develop and demonstrate the technology base required to provide a wide range of modular power systems as well as allowing mission independence from solar and orbital attitude requirements. Several recent advancements in CSTI High Capacity power development will be discussed

  7. Characterization of a high-intensity three-qubit GHZ state using state tomography and Gisin's inequality

    Energy Technology Data Exchange (ETDEWEB)

    Lu Huaixin, E-mail: huaixinlu@wfu.edu.c [Department of Physics and Electronic Science, Weifang University, Weifang, Shandong 261061 (China); Zhao Jiaqiang; Wang Xiaoqin [Department of Physics and Electronic Science, Weifang University, Weifang, Shandong 261061 (China)

    2011-05-02

    We experimentally characterized a high-intensity optical three-qubit Greenberger-Horne-Zeilinger (GHZ) states with a count of {approx}25/s by using the method of over-complete state tomography. Furthermore, based on the state, a convincing, 3.5 standard deviations, violation of Gisin's inequality has been measured, thus confirming the validity of Gisin's inequality for three-qubit GHZ states. From the data, we verified the good agreement of the experimental violation with the value predicted by quantum mechanics given the reconstructed density matrix. This result represents the first step towards the experimental implementation of Gisin's theorem. - Highlights: We have characterized a high-intensity three-qubit GHZ states. We have achieved convincing results of the violation of Gisin's inequalities. We verified the agreement of the experimental violation with theoretical value.

  8. VizieR Online Data Catalog: ACT high significance 148 and 218GHz sources (Marsden+, 2014)

    Science.gov (United States)

    Marsden, D.; Gralla, M.; Marriage, T. A.; Switzer, E. R.; Partridge, B.; Massardi, M.; Morales, G.; Addison, G.; Bond, J. R.; Crichton, D.; Das, S.; Devlin, M.; Dunner, R.; Hajian, A.; Hilton, M.; Hincks, A.; Hughes, J. P.; Irwin, K.; Kosowsky, A.; Menanteau, F.; Moodley, K.; Niemack, M.; Page, L.; Reese, E. D.; Schmitt, B.; Sehgal, N.; Sievers, J.; Staggs, S.; Swetz, D.; Thornton, R.; Wollack, E.

    2014-11-01

    The ACT experiment (Swetz et al., 2011ApJS..194...41S) is situated on the slopes of Cerro Toco in the Atacama Desert of Chile at an elevation of 5190m. ACT's latitude gives access to both the northern and southern celestial hemispheres. Observations occurred simultaneously in three frequency bands, at 148GHz (2.0mm), 218GHz (1.4mm) and 277GHz (1.1mm) with angular resolutions of roughly 1.4 , 1.0 and 0.9-arcmin, respectively. (1 data file).

  9. 77 GHz MEMS antennas on high-resistivity silicon for linear and circular polarization

    KAUST Repository

    Sallam, M. O.

    2011-07-01

    Two new MEMS antennas operating at 77 GHz are presented in this paper. The first antenna is linearly polarized. It possesses a vertical silicon wall that carries a dipole on top of it. The wall is located on top of silicon substrate covered with a ground plane. The other side of the substrate carries a microstrip feeding network in the form of U-turn that causes 180 phase shift. This phase-shifter feeds the arms of the dipole antenna via two vertical Through-Silicon Vias (TSVs) that go through the entire wafer. The second antenna is circularly polarized and formed using two linearly polarized antennas spatially rotated with respect to each other by 90 and excited with 90 phase shift. Both antennas are fabricated using novel process flow on a single high-resistivity silicon wafer via bulk micromachining. Only three processing steps are required to fabricate these antennas. The proposed antennas have appealing characteristics, such as high polarization purity, high gain, and high radiation efficiency. © 2011 IEEE.

  10. Resonant High Power Combiners

    CERN Document Server

    Langlois, Michel; Peillex-Delphe, Guy

    2005-01-01

    Particle accelerators need radio frequency sources. Above 300 MHz, the amplifiers mostly used high power klystrons developed for this sole purpose. As for military equipment, users are drawn to buy "off the shelf" components rather than dedicated devices. IOTs have replaced most klystrons in TV transmitters and find their way in particle accelerators. They are less bulky, easier to replace, more efficient at reduced power. They are also far less powerful. What is the benefit of very compact sources if huge 3 dB couplers are needed to combine the power? To alleviate this drawback, we investigated a resonant combiner, operating in TM010 mode, able to combine 3 to 5 IOTs. Our IOTs being able to deliver 80 kW C.W. apiece, combined power would reach 400 kW minus the minor insertion loss. Values for matching and insertion loss are given. The behavior of the system in case of IOT failure is analyzed.

  11. High-power klystrons

    Science.gov (United States)

    Siambis, John G.; True, Richard B.; Symons, R. S.

    1994-05-01

    Novel emerging applications in advanced linear collider accelerators, ionospheric and atmospheric sensing and modification and a wide spectrum of industrial processing applications, have resulted in microwave tube requirements that call for further development of high power klystrons in the range from S-band to X-band. In the present paper we review recent progress in high power klystron development and discuss some of the issues and scaling laws for successful design. We also discuss recent progress in electron guns with potential grading electrodes for high voltage with short and long pulse operation via computer simulations obtained from the code DEMEOS, as well as preliminary experimental results. We present designs for high power beam collectors.

  12. Developmental activities of the 18 GHz high temperature superconducting ECR ion source, PKDELIS, for the high current injector at IUAC

    International Nuclear Information System (INIS)

    Rodrigues, G.; Lakshmy, P.S.; Mathur, Y.; Ahuja, R.; Dutt, R.N.; Rao, U.K.; Mandal, A.; Kanjilal, D.; Roy, A.

    2011-01-01

    Various developmental activities of the 18 GHz High Temperature Superconducting ECR Ion Source, PKDELIS have been carried out as a part of the High Current Injector programme. Emittance measurements using a simple technique has given important inputs for the design of downstream accelerators like RFQ, DTL and low beta cavities. The techniques allows for emittance matching by varying the emittance parameters to match with the acceptance of the accelerators. X-ray Beamstrahlung measurements from ECR plasma has shown that it is a diagnostic tool to optimize the production of highly charged ions. The ion optics through the low energy beam transport section has been benchmarked with various codes and given a handle to optimize the transmission. New techniques to improve the extraction efficiency of highly charged ions has been developed. (author)

  13. High power microwaves

    CERN Document Server

    Benford, James; Schamiloglu, Edl

    2016-01-01

    Following in the footsteps of its popular predecessors, High Power Microwaves, Third Edition continues to provide a wide-angle, integrated view of the field of high power microwaves (HPMs). This third edition includes significant updates in every chapter as well as a new chapter on beamless systems that covers nonlinear transmission lines. Written by an experimentalist, a theorist, and an applied theorist, respectively, the book offers complementary perspectives on different source types. The authors address: * How HPM relates historically and technically to the conventional microwave field * The possible applications for HPM and the key criteria that HPM devices have to meet in order to be applied * How high power sources work, including their performance capabilities and limitations * The broad fundamental issues to be addressed in the future for a wide variety of source types The book is accessible to several audiences. Researchers currently in the field can widen their understanding of HPM. Present or pot...

  14. 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.

  15. A 65 nm CMOS high efficiency 50 GHz VCO with regard to the coupling effect of inductors

    International Nuclear Information System (INIS)

    Ye Yu; Tian Tong

    2013-01-01

    A 50 GHz cross-coupled voltage controlled oscillator (VCO) considering the coupling effect of inductors based on a 65 nm standard complementary metal oxide semiconductor (CMOS) technology is reported. A pair of inductors has been fabricated, measured and analyzed to characterize the coupling effects of adjacent inductors. The results are then implemented to accurately evaluate the VCO's LC tank. By optimizing the tank voltage swing and the buffer's operation region, the VCO achieves a maximum efficiency of 11.4% by generating an average output power of 2.5 dBm while only consuming 19.7 mW (including buffers). The VCO exhibits a phase noise of −87 dBc/Hz at 1 MHz offset, leading to a figure of merit (FoM) of −167.5 dB/Hz and a tuning range of 3.8% (from 48.98 to 50.88 GHz). (semiconductor integrated circuits)

  16. A High-Gradient Test of a 30 GHz Molybdenum-Iris Structure

    CERN Document Server

    Wuensch, Walter; Braun, H; Carron, G; Corsini, R; Döbert, Steffen; Fandos, R; Grudiev, A; Jensen, E; Mete, Ö; Ramsvik, T; Rodríguez, José Alberto; Sladen, Jonathan P H; Syratchev, I V; Taborelli, M; Tecker, F A; Urschütz, Peter; Wilson, Ian H; CERN. Geneva

    2006-01-01

    The CLIC study is actively investigating a number of different materials in an effort to find ways to increase achievable accelerating gradient. So far a series of rf tests have been made with a set of identical-geometry structures: a W-iris 30 GHz structure, a Mo-iris 30 GHz structure (with pulses as long as 16 ns) and a scaled Mo-iris X-band structure. A second Mo-iris 30 GHz structure of the same geometry has now been tested in CTF3 with pulse lengths up to 350 ns. The structure was conditioned to a gradient of 140 MV/m with a 70 ns pulse length and a breakdown rate slope of 13 MV/m per decade has been measured

  17. Blood-brain barrier permeation in the rat during exposure to low-power 1.7-GHz microwave radiation

    International Nuclear Information System (INIS)

    Ward, T.R.; Ali, J.S.

    1985-01-01

    The permeability of the blood-brain barrier to high-and low-molecular-weight compounds has been measured as a function of continuous-wave (CW) and pulsed-microwave radiation. Adult rats, anesthetized with pentobarbital and injected intravenously with a mixture of [ 14 C] sucrose and [ 3 H] inulin, were exposed for 30 min at a specific absorption rate of 0.1 W/kg to 1.7-GHz CW and pulsed (0.5-microseconds pulse width, 1,000 pps) microwaves. After exposure, the brain was perfused and sectioned into nine regions, and the radioactivity in each region was counted. During identical exposure conditions, temperatures of rats were measured in eight of the brain regions by a thermistor probe that did not perturb the field. No change in uptake of either tracer was found in any of the eight regions as compared with those of sham-exposed animals

  18. Switching power converters medium and high power

    CERN Document Server

    Neacsu, Dorin O

    2013-01-01

    An examination of all of the multidisciplinary aspects of medium- and high-power converter systems, including basic power electronics, digital control and hardware, sensors, analog preprocessing of signals, protection devices and fault management, and pulse-width-modulation (PWM) algorithms, Switching Power Converters: Medium and High Power, Second Edition discusses the actual use of industrial technology and its related subassemblies and components, covering facets of implementation otherwise overlooked by theoretical textbooks. The updated Second Edition contains many new figures, as well as

  19. Optimization of high-definition video coding and hybrid fiber-wireless transmission in the 60 GHz band

    DEFF Research Database (Denmark)

    Lebedev, Alexander; Pham, Tien Thang; Beltrán, Marta

    2011-01-01

    The paper addresses the problem of distribution of highdefinition video over fiber-wireless networks. The physical layer architecture with the low complexity envelope detection solution is investigated. We present both experimental studies and simulation of high quality high-definition compressed...... video transmission over 60 GHz fiberwireless link. Using advanced video coding we satisfy low complexity and low delay constraints, meanwhile preserving the superb video quality after significantly extended wireless distance. © 2011 Optical Society of America....

  20. Fast power measurement on a 30 GHz/15 kW gyrotron

    International Nuclear Information System (INIS)

    Saala, G.

    2004-09-01

    This work has been developed in the scope of a study-thesis at the Universitaet Karlsruhe (TH). The realization took place at the Institut fuer Hochleistungsimpuls- und Mikrowellentechnik (IHM) at the Forschungszentrum Karlsruhe (FZK). The aim was to investigate the possibilities of a fast power measurement at a compact, industrial gyrotron-system. To measure the output-power a small fraction of the gyrotron microwave radiation is coupled out and analyzed using a diode-detector. At the beginning of the work a mirror of the quasi-optical transmission line with a built in λ/4-coupler was available. This built-in coupler and other coupling structures which have been set up during this work have been characterized. To be able to perform reproduceable measurements several computer programs have been developed. Using these programs the gyrotron-system can be remote-controlled from a PC. The diode-detector signal has been analyzed under different conditions of gyrotron operation with respect to its short-term- and long-term-stability. After that the dependency of the calorimetrically measured output-power of the gyrotron has been used to calibrate the diode-voltage. (orig.)

  1. The Atacama Cosmology Telescope: A Measurement of the Cosmic Microwave Background Power Spectrum at 148 AND 218 GHz from the 2008 Southern Survey

    Science.gov (United States)

    Das, Sudeep; Marriage, Tobias A.; Ade, Peter A. R.; Aguirre, Paula; Amiri, Mandana; Appel, John W.; Barrientos, L. Felipe; Battistelli, Elia A.; Bond, J. Richard; Brown, Ben; hide

    2010-01-01

    We present measurements of the cosmic microwave background (CMB) power spectrum made by the Atacama Cosmology Telescope at 148 GHz and 218 GHz, as well as the cross-frequency spectrum between the two channels. Our results dearly show the second through the seventh acoustic peaks in the CMB power spectrum. The measurements of these higher-order peaks provide an additional test of the ACDM cosmological model. At l > 3000, we detect power in excess of the primary anisotropy spectrum of the CMB. At lower multipoles 500 < l < 3000, we find evidence for gravitational lensing of the CMB in the power spectrum at the 2.8(sigma) level. We also detect a low level of Galactic dust in our maps, which demonstrates that we can recover known faint, diffuse signals.

  2. An RF-to-DC energy harvester for co-integration in a low-power 2.4 GHz transceiver frontend

    NARCIS (Netherlands)

    Masuch, J.; Delgado-Restituto, M.; Milosevic, D.; Baltus, P.G.M.

    2012-01-01

    A 2.4 GHz energy harvester for co-integration into a low-power transceiver (TRx) operating at the same frequency is presented. An RF switch decouples the harvester from the TRx and keeps the performance degradation of the TRx low, i.e. 0.2 dB reduced output power in Tx-mode and 0.4 dB reduced

  3. Human speech articulator measurements using low power, 2GHz Homodyne sensors

    International Nuclear Information System (INIS)

    Barnes, T; Burnett, G C; Holzrichter, J F

    1999-01-01

    Very low power, short-range microwave ''radar-like'' sensors can measure the motions and vibrations of internal human speech articulators as speech is produced. In these animate (and also in inanimate acoustic systems) microwave sensors can measure vibration information associated with excitation sources and other interfaces. These data, together with the corresponding acoustic data, enable the calculation of system transfer functions. This information appears to be useful for a surprisingly wide range of applications such as speech coding and recognition, speaker or object identification, speech and musical instrument synthesis, noise cancellation, and other applications

  4. Human speech articulator measurements using low power, 2GHz Homodyne sensors

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, T; Burnett, G C; Holzrichter, J F

    1999-06-29

    Very low power, short-range microwave ''radar-like'' sensors can measure the motions and vibrations of internal human speech articulators as speech is produced. In these animate (and also in inanimate acoustic systems) microwave sensors can measure vibration information associated with excitation sources and other interfaces. These data, together with the corresponding acoustic data, enable the calculation of system transfer functions. This information appears to be useful for a surprisingly wide range of applications such as speech coding and recognition, speaker or object identification, speech and musical instrument synthesis, noise cancellation, and other applications.

  5. RF link for Implanted Medical Devices (IMDs) and Sub-GHz Inductive Power Transmission

    OpenAIRE

    Diet , Antoine; Koulouridis , Satvros; Le Bihan , Yann; Luu , Quang-Trung; Meyer , Olivier; Pichon , Lionel; Biancheri-Astier , Marc

    2017-01-01

    International audience; Ce travail s'inscrit dan sune etude exploratoire sur les possibilités de télé-alimentation RF des implants médicaux et/ou de communication entre eux. En effet, la durée de fonctionnement de certains implants avec batterie rend leur utilisation critique car il ne faut pas privilégier une intervention chirurgicale lourde s'il est possible d'agir de manière non-invasive. La transmission d'énergie sans fil ou WPT (Wireless Power Transfer) est au cœur de nombreuses autres t...

  6. High-Gradient Test of a 3 GHz Single-Cell Cavity

    CERN Document Server

    Verdú-Andrés, S; Bonomi, R; Degiovanni, A; Garlasché, M; Garonna, A; Mellace, C; Pearce, P; S. Verdú-Andrés; Wegner, R

    2010-01-01

    Pro­ton and car­bon ion beams pre­sent ad­van­ta­geous depth-dose dis­tri­bu­tions with re­spect to X-rays. Car­bon ions allow a bet­ter con­trol of "ra­diore­sis­tant" tu­mours due to their high­er bi­o­log­i­cal re­sponse. For deep-seat­ed tu­mours pro­ton and car­bon ion beams of some nA and en­er­gies of about 200 MeV and 400 MeV/u re­spec­tive­ly are need­ed. For these ap­pli­ca­tions TERA pro­posed the "cy­clinac": a high-fre­quen­cy linac which boosts the hadrons ac­cel­er­at­ed by a cy­clotron. The di­men­sions of the com­plex can be re­duced if high­er ac­cel­er­at­ing gra­di­ents are achieved in the linac. To test the max­i­mum achiev­able fields, a 3 GHz cav­i­ty has been built by TERA. The 19 mm-long cell is fore­seen to be ex­cit­ed at 200 Hz by 3 us RF puls­es and should reach a 40 MV/m ac­cel­er­at­ing gra­di­ent, which cor­re­sponds to a peak sur­face elec­tric field Es of 260 MV/m. In a first high-pow­er test per­for...

  7. Gyromagnetic nonlinear transmission line generator of high voltage pulses modulated at 4 GHz frequency with 1000 Hz pulse repetition rate

    International Nuclear Information System (INIS)

    Ulmasculov, M R; Sharypov, K A; Shunailov, S A; Shpak, V G; Yalandin, M I; Pedos, M S; Rukin, S N

    2017-01-01

    Results of testing of a generator based on a solid-state drive and the parallel gyromagnetic nonlinear transmission lines with external bias are presented. Stable rf-modulated high-voltage nanosecond pulses were shaped in each of the four channels in 1 s packets with 1000 Hz repetition frequencies. Pulse amplitude reaches -175 kV, at a modulation depth of rf-oscillations to 50 % and the effective frequency ∼4 GHz. (paper)

  8. Development of a 200 W CW high efficiency traveling wave tube at 12 GHz. [for use in communication technology satellites

    Science.gov (United States)

    Christensen, J. A.; Tammaru, I.

    1974-01-01

    The design, development, and test results are reported for an experimental PPM focused, traveling-wave tube that produces 235 watts of CW RF power over 85 MHz centered at 12.080 GHz. The tube uses a coupled cavity RF circuit with a velocity taper for greater than 30 percent basic efficiency. Overall efficiency of 51 percent is achieved by means of a nine stage depressed collector designed at NASA Lewis Research Center. This collector is cooled by direct radiation to deep space.

  9. 1.3 GHz superconducting RF cavity program at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Ginsburg, C.M.; Arkan, T.; Barbanotti, S.; Carter, H.; Champion, M.; Cooley, L.; Cooper, C.; Foley, M.; Ge, M.; Grimm, C.; Harms, E.; /Fermilab

    2011-03-01

    At Fermilab, 9-cell 1.3 GHz superconducting RF (SRF) cavities are prepared, qualified, and assembled into cryomodules (CMs) for Project X, an International Linear Collider (ILC), or other future projects. The 1.3 GHz SRF cavity program includes targeted R&D on 1-cell 1.3 GHz cavities for cavity performance improvement. Production cavity qualification includes cavity inspection, surface processing, clean assembly, and one or more cryogenic low-power CW qualification tests which typically include performance diagnostics. Qualified cavities are welded into helium vessels and are cryogenically tested with pulsed high-power. Well performing cavities are assembled into cryomodules for pulsed high-power testing in a cryomodule test facility, and possible installation into a beamline. The overall goals of the 1.3 GHz SRF cavity program, supporting facilities, and accomplishments are described.

  10. A High Voltage Swing 1.9 GHz PA in Standard CMOS

    NARCIS (Netherlands)

    Aartsen, W.A.J.; Annema, Anne J.; Nauta, Bram

    2002-01-01

    A circuit technique for RF power amplifiers that reliably handle voltage peaks well above the nominal supply voltage is presented. To achieve this high-voltage tolerance the circuit implements switched-cascode transistors that yield reliable operation for voltages up to 7V at RF frequencies in a

  11. High power gyrotrons: a close perspective

    International Nuclear Information System (INIS)

    Kartikeyan, M.V.

    2012-01-01

    Gyrotrons and their variants, popularly known as gyrodevices are millimetric wave sources provide very high powers ranging from long pulse to continuous wave (CW) for various technological, scientific and industrial applications. From their conception (monotron-version) in the late fifties until their successful development for various applications, these devices have come a long way technologically and made an irreversible impact on both users and developers. The possible applications of high power millimeter and sub-millimeter waves from gyrotrons and their variants (gyro-devices) span a wide range of technologies. The plasma physics community has already taken advantage of the recent advances of gyrotrons in the areas of RF plasma production, heating, non-inductive current drive, plasma stabilization and active plasma diagnostics for magnetic confinement thermonuclear fusion research, such as lower hybrid current drive (LHCD) (8 GHz), electron cyclotron resonance heating (ECRH) (28-170-220 GHz), electron cyclotron current drive (ECCD), collective Thomson scattering (CTS), heat-wave propagation experiments, and space-power grid (SPG) applications. Other important applications of gyrotrons are electron cyclotron resonance (ECR) discharges for the generation of multi- charged ions and soft X-rays, as well as industrial materials processing and plasma chemistry. Submillimeter wave gyrotrons are employed in high frequency, broadband electron paramagnetic resonance (EPR) spectroscopy. Additional future applications await the development of novel high power gyro-amplifiers and devices for high resolution radar ranging and imaging in atmospheric and planetary science as well as deep space and specialized satellite communications, RF drivers for next generation high gradient linear accelerators (supercolliders), high resolution Doppler radar, radar ranging and imaging in atmospheric and planetary science, drivers for next-generation high-gradient linear accelerators

  12. 60-GHz integrated-circuit high data rate quadriphase shift keying exciter and modulator

    Science.gov (United States)

    Grote, A.; Chang, K.

    1984-01-01

    An integrated-circuit quadriphase shift keying (QPSK) exciter and modulator have demonstrated excellent performance directly modulating a carrier frequency of 60 GHz with an output phase error of less than 3 degrees and maximum amplitude error of 0.5 dB. The circuit consists of a 60-GHz Gunn VCO phase-locked to a low-frequency reference source, a 4th subharmonic mixer, and a QPSK modlator packaged into a small volume of 1.8 x 2.5 x 0.35 in. The use of microstrip has the advantages of small size, light-weight, and low-cost fabrication. The unit has the potential for multigigabit data rate applications.

  13. High Power Density Motors

    Science.gov (United States)

    Kascak, Daniel J.

    2004-01-01

    With the growing concerns of global warming, the need for pollution-free vehicles is ever increasing. Pollution-free flight is one of NASA's goals for the 21" Century. , One method of approaching that goal is hydrogen-fueled aircraft that use fuel cells or turbo- generators to develop electric power that can drive electric motors that turn the aircraft's propulsive fans or propellers. Hydrogen fuel would likely be carried as a liquid, stored in tanks at its boiling point of 20.5 K (-422.5 F). Conventional electric motors, however, are far too heavy (for a given horsepower) to use on aircraft. Fortunately the liquid hydrogen fuel can provide essentially free refrigeration that can be used to cool the windings of motors before the hydrogen is used for fuel. Either High Temperature Superconductors (HTS) or high purity metals such as copper or aluminum may be used in the motor windings. Superconductors have essentially zero electrical resistance to steady current. The electrical resistance of high purity aluminum or copper near liquid hydrogen temperature can be l/lOO* or less of the room temperature resistance. These conductors could provide higher motor efficiency than normal room-temperature motors achieve. But much more importantly, these conductors can carry ten to a hundred times more current than copper conductors do in normal motors operating at room temperature. This is a consequence of the low electrical resistance and of good heat transfer coefficients in boiling LH2. Thus the conductors can produce higher magnetic field strengths and consequently higher motor torque and power. Designs, analysis and actual cryogenic motor tests show that such cryogenic motors could produce three or more times as much power per unit weight as turbine engines can, whereas conventional motors produce only 1/5 as much power per weight as turbine engines. This summer work has been done with Litz wire to maximize the current density. The current is limited by the amount of heat it

  14. High-power electronics

    CERN Document Server

    Kapitsa, Petr Leonidovich

    1966-01-01

    High-Power Electronics, Volume 2 presents the electronic processes in devices of the magnetron type and electromagnetic oscillations in different systems. This book explores the problems of electronic energetics.Organized into 11 chapters, this volume begins with an overview of the motion of electrons in a flat model of the magnetron, taking into account the in-phase wave and the reverse wave. This text then examines the processes of transmission of electromagnetic waves of various polarization and the wave reflection from grids made of periodically distributed infinite metal conductors. Other

  15. High Power Vanadate lasers

    CSIR Research Space (South Africa)

    Strauss

    2006-07-01

    Full Text Available stream_source_info Strauss1_2006.pdf.txt stream_content_type text/plain stream_size 3151 Content-Encoding UTF-8 stream_name Strauss1_2006.pdf.txt Content-Type text/plain; charset=UTF-8 Laser Research Institute... University of Stellenbosch www.laser-research.co.za High Power Vanadate lasers H.J.Strauss, Dr. C. Bollig, R.C. Botha, Prof. H.M. von Bergmann, Dr. J.P. Burger Aims 1) To develop new techniques to mount laser crystals, 2) compare the lasing properties...

  16. High-Capacity 60 GHz and 75–110 GHz Band Links Employing All-Optical OFDM Generation and Digital Coherent Detection

    DEFF Research Database (Denmark)

    Caballero Jambrina, Antonio; Zibar, Darko; Sambaraju, Rakesh

    2012-01-01

    The performance of wireless signal generation and detection at millimeter-wave frequencies using baseband optical means is analyzed and experimentally demonstrated. Multigigabit wireless signal generation is achieved based on all-optical orthogonal frequency division multiplexing (OFDM) and photo......The performance of wireless signal generation and detection at millimeter-wave frequencies using baseband optical means is analyzed and experimentally demonstrated. Multigigabit wireless signal generation is achieved based on all-optical orthogonal frequency division multiplexing (OFDM...... scalability and bit-rate transparency of our proposed approach, we experimentally demonstrated generation and detection in the 60 GHz and 75–110 GHz band of an all-optical OFDM quadrature phase shift keying, with two and three subcarriers, for a total bit rate over 20 Gb/ s....

  17. High power coaxial ubitron

    Science.gov (United States)

    Balkcum, Adam J.

    In the ubitron, also known as the free electron laser, high power coherent radiation is generated from the interaction of an undulating electron beam with an electromagnetic signal and a static periodic magnetic wiggler field. These devices have experimentally produced high power spanning the microwave to x-ray regimes. Potential applications range from microwave radar to the study of solid state material properties. In this dissertation, the efficient production of high power microwaves (HPM) is investigated for a ubitron employing a coaxial circuit and wiggler. Designs for the particular applications of an advanced high gradient linear accelerator driver and a directed energy source are presented. The coaxial ubitron is inherently suited for the production of HPM. It utilizes an annular electron beam to drive the low loss, RF breakdown resistant TE01 mode of a large coaxial circuit. The device's large cross-sectional area greatly reduces RF wall heat loading and the current density loading at the cathode required to produce the moderate energy (500 keV) but high current (1-10 kA) annular electron beam. Focusing and wiggling of the beam is achieved using coaxial annular periodic permanent magnet (PPM) stacks without a solenoidal guide magnetic field. This wiggler configuration is compact, efficient and can propagate the multi-kiloampere electron beams required for many HPM applications. The coaxial PPM ubitron in a traveling wave amplifier, cavity oscillator and klystron configuration is investigated using linear theory and simulation codes. A condition for the dc electron beam stability in the coaxial wiggler is derived and verified using the 2-1/2 dimensional particle-in-cell code, MAGIC. New linear theories for the cavity start-oscillation current and gain in a klystron are derived. A self-consistent nonlinear theory for the ubitron-TWT and a new nonlinear theory for the ubitron oscillator are presented. These form the basis for simulation codes which, along

  18. 11.9 W output power at 4 GHz from 1 mm AlGaN/GaN HEMT

    NARCIS (Netherlands)

    Krämer, M.C.J.C.M.; Karouta, F.; Kwaspen, J.J.M.; Rudzinski, M.; Larsen, P.K.; Suijker, E.M.; Hek, P.A. de; Rödle, T.; Volokhine, I.; Kaufmann, L.M.F.

    2008-01-01

    A high electrical breakdown field combined with a high electron saturation velocity make GaN very attractive for high power high frequency electronics. The maximum drain current densities of AlGaN/GaN HFETs range from 1.0 A/mm to 1.5 A/mm [1-3]. Hence, it is obvious that breakdown voltages over 160

  19. Multiscale Thermo-Mechanical Design and Analysis of High Frequency and High Power Vacuum Electron Devices

    Science.gov (United States)

    Gamzina, Diana

    Diana Gamzina March 2016 Mechanical and Aerospace Engineering Multiscale Thermo-Mechanical Design and Analysis of High Frequency and High Power Vacuum Electron Devices Abstract A methodology for performing thermo-mechanical design and analysis of high frequency and high average power vacuum electron devices is presented. This methodology results in a "first-pass" engineering design directly ready for manufacturing. The methodology includes establishment of thermal and mechanical boundary conditions, evaluation of convective film heat transfer coefficients, identification of material options, evaluation of temperature and stress field distributions, assessment of microscale effects on the stress state of the material, and fatigue analysis. The feature size of vacuum electron devices operating in the high frequency regime of 100 GHz to 1 THz is comparable to the microstructure of the materials employed for their fabrication. As a result, the thermo-mechanical performance of a device is affected by the local material microstructure. Such multiscale effects on the stress state are considered in the range of scales from about 10 microns up to a few millimeters. The design and analysis methodology is demonstrated on three separate microwave devices: a 95 GHz 10 kW cw sheet beam klystron, a 263 GHz 50 W long pulse wide-bandwidth sheet beam travelling wave tube, and a 346 GHz 1 W cw backward wave oscillator.

  20. High power communication satellites power systems study

    International Nuclear Information System (INIS)

    Josloff, A.T.; Peterson, J.R.

    1994-01-01

    This paper discusses a DOE-funded study to evaluate the commercial attractiveness of high power communication satellites and assesses the attributes of both conventional photovoltaic and reactor power systems. This study brings together a preeminent US Industry/Russian team to cooperate on the role of high power communication satellites in the rapidly expanding communications revolution. These high power satellites play a vital role in assuring availability of universally accessible, wide bandwidth communications, for high definition TV, super computer networks and other services. Satellites are ideally suited to provide the wide bandwidths and data rates required and are unique in the ability to provide services directly to the users. As new or relocated markets arise, satellites offer a flexibility that conventional distribution services cannot match, and it is no longer necessary to be near population centers to take advantage of the telecommunication revolution. The geopolitical implications of these substantially enhanced communications capabilities will be significant

  1. Construction of a single/multiple wavelength RZ optical pulse source at 40 GHz by use of wavelength conversion in a high-nonlinearity DSF-NOLM

    DEFF Research Database (Denmark)

    Yu, Jianjun; Yujun, Qian; Jeppesen, Palle

    2001-01-01

    A single or multiple wavelength RZ optical pulse source at 40 GHz is successfully obtained by using wavelength conversion in a nonlinear optical loop mirror consisting of high nonlinearity-dispersion shifted fiber.......A single or multiple wavelength RZ optical pulse source at 40 GHz is successfully obtained by using wavelength conversion in a nonlinear optical loop mirror consisting of high nonlinearity-dispersion shifted fiber....

  2. A study of 60 GHz intersatellite link applications

    Science.gov (United States)

    Anzic, G.; Connolly, D. J.; Haugland, E. J.; Kosmahl, H. G.; Chitwood, J. S.

    Applications of intersatellite links operating at 60 GHz are reviewed. Likely scenarios, ranging from transmission of moderate and high data rates over long distances to low data rates over short distances are examined. A limited parametric tradeoff is performed with system variables such as radiofrequency power, receiver noise temperature, link distance, data rate, and antenna size. Present status is discussed and projections are given for both electron tube and solid state transmitter technologies. Monolithic transmit and receive module technology, already under development at 20 to 30 GHz, is reviewed and its extension to 60 GHz, and possible applicability is discussed.

  3. A study of 60 GHz intersatellite link applications

    Science.gov (United States)

    Anzic, G.; Connolly, D. J.; Haugland, E. J.; Kosmahl, H. G.; Chitwood, J. S.

    1983-01-01

    Applications of intersatellite links operating at 60 GHz are reviewed. Likely scenarios, ranging from transmission of moderate and high data rates over long distances to low data rates over short distances are examined. A limited parametric tradeoff is performed with system variables such as radiofrequency power, receiver noise temperature, link distance, data rate, and antenna size. Present status is discussed and projections are given for both electron tube and solid state transmitter technologies. Monolithic transmit and receive module technology, already under development at 20 to 30 GHz, is reviewed and its extension to 60 GHz, and possible applicability is discussed.

  4. 5.2 GHz variable-gain amplifier and power amplifier driver for WLAN IEEE 802.11a transmitter front-end

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Xuelian; Yan Jun; Shi Yin [Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Foster, Dai Fa, E-mail: xlzhang@semi.ac.c [Department of Electrical and Computer Engineering, Auburn University, Auburn, AL 36849-5201 (United States)

    2009-01-15

    A 5.2 GHz variable-gain amplifier (VGA) and a power amplifier (PA) driver are designed for WLAN IEEE 802.11a monolithic RFIC. The VGA and the PA driver are implemented in a 50 GHz 0.35 mum SiGe BiCMOS technology and occupy 1.12 x 1.25 mm{sup 2} die area. The VGA with effective temperature compensation is controlled by 5 bits and has a gain range of 34 dB. The PA driver with tuned loads utilizes a differential input, single-ended output topology, and the tuned loads resonate at 5.2 GHz. The maximum overall gain of the VGA and the PA driver is 29 dB with the output third-order intercept point (OIP3) of 11 dBm. The gain drift over the temperature varying from -30 to 85 deg. C converges within +-3 dB. The total current consumption is 45 mA under a 2.85 V power supply.

  5. Nuclear power flies high

    International Nuclear Information System (INIS)

    Friedman, S.T.

    1983-01-01

    Nuclear power in aircraft, rockets and satellites is discussed. No nuclear-powered rockets or aircraft have ever flown, but ground tests were successful. Nuclear reactors are used in the Soviet Cosmos serles of satellites, but only one American satellite, the SNAP-10A, contained a reactor. Radioisotope thermoelectric generators, many of which use plutonium 238, have powered more than 20 satellites launched into deep space by the U.S.A

  6. High field Q slope and the effect of low-temperature baking at 3 GHz

    Directory of Open Access Journals (Sweden)

    G. Ciovati

    2018-01-01

    Full Text Available A strong degradation of the unloaded quality factor with field, called high field Q slope, is commonly observed above B_{p}≅100  mT in elliptical superconducting niobium cavities at 1.3 and 1.5 GHz. In the present experiments several 3 GHz niobium cavities were measured up to and above B_{p}≅100  mT. The measurements show that a high field Q slope phenomenon limits the field reach at this frequency, that the high field Q slope onset field depends weakly on the frequency, and that the high field Q slope can be removed by the typical empirical solution of electropolishing followed by heating to 120°C for 48 hrs. In addition, one of the cavities reached a quench field of 174 mT and its field dependence of the quality factor was compared against global heating predicted by a thermal feedback model.

  7. Superconducting ECR ion source: From 24-28 GHz SECRAL to 45 GHz fourth generation ECR

    Science.gov (United States)

    Zhao, H. W.; Sun, L. T.; Guo, J. W.; Zhang, W. H.; Lu, W.; Wu, W.; Wu, B. M.; Sabbi, G.; Juchno, M.; Hafalia, A.; Ravaioli, E.; Xie, D. Z.

    2018-05-01

    The development of superconducting ECR source with higher magnetic fields and higher microwave frequency is the most straight forward path to achieve higher beam intensity and higher charge state performance. SECRAL, a superconducting third generation ECR ion source, is designed for 24-28 GHz microwave frequency operation with an innovative magnet configuration of sextupole coils located outside the three solenoids. SECRAL at 24 GHz has already produced a number of record beam intensities, such as 40Ar12+ 1.4 emA, 129Xe26+ 1.1 emA, 129Xe30+ 0.36 emA, and 209Bi31+ 0.68 emA. SECRAL-II, an upgraded version of SECRAL, was built successfully in less than 3 years and has recently been commissioned at full power of a 28 GHz gyrotron and three-frequency heating (28 + 45 + 18 GHz). New record beam intensities for highly charged ion production have been achieved, such as 620 eμA 40Ar16+, 15 eμA 40Ar18+, 146 eμA 86Kr28+, 0.5 eμA 86Kr33+, 53 eμA 129Xe38+, and 17 eμA 129Xe42+. Recent beam test results at SECRAL and SECRAL II have demonstrated that the production of more intense highly charged heavy ion beams needs higher microwave power and higher frequency, as the scaling law predicted. A 45 GHz superconducting ECR ion source FECR (a first fourth generation ECR ion source) is being built at IMP. FECR will be the world's first Nb3Sn superconducting-magnet-based ECR ion source with 6.5 T axial mirror field, 3.5 T sextupole field on the plasma chamber inner wall, and 20 kW at a 45 GHz microwave coupling system. This paper will focus on SECRAL performance studies at 24-28 GHz and technical design of 45 GHz FECR, which demonstrates a technical path for highly charged ion beam production from 24 to 28 GHz SECRAL to 45 GHz FECR.

  8. A 25 W 70% Efficiency Doherty Power Amplifier at 6 dB Output Back-Off for 2.4 GHz Applications with VGS, PEAK

    Directory of Open Access Journals (Sweden)

    Jorge Moreno Rubio

    2015-01-01

    Full Text Available This paper shows the design and simulation results of a hybrid Doherty power amplifier. The amplifier has been designed at 2,4 GHz, obtaining power-added efficiency above 70 % for 6 dB output power back-off, together with a small signal gain of 17 dB. Design and analysis equations are presented considering class AB bias conditions for the main amplifier and class C for the peak one in back-off larger than 6 dB, and FET device assumption. An additional control on the bias point of the peak device has been carried out, in order to increase the gain on the Doherty region and ease the design of the peak branch. A Cree’s GaN-HEMT CGH40010F device has been used with a nonlinear model guarantied up to 6 GHz and with an expected output power of 10 W. The obtained output power is higher than 25-W. The simulation has been carried out using Agilent ADS CAD tools. The present design could present the state of the art in terms of continuous-wave (CW characterization

  9. High Efficiency Power Converter for Low Voltage High Power Applications

    DEFF Research Database (Denmark)

    Nymand, Morten

    The topic of this thesis is the design of high efficiency power electronic dc-to-dc converters for high-power, low-input-voltage to high-output-voltage applications. These converters are increasingly required for emerging sustainable energy systems such as fuel cell, battery or photo voltaic based......, and remote power generation for light towers, camper vans, boats, beacons, and buoys etc. A review of current state-of-the-art is presented. The best performing converters achieve moderately high peak efficiencies at high input voltage and medium power level. However, system dimensioning and cost are often...

  10. High power communication satellites power systems study

    Science.gov (United States)

    Josloff, Allan T.; Peterson, Jerry R.

    1995-01-01

    This paper discusses a planned study to evaluate the commercial attractiveness of high power communication satellites and assesses the attributes of both conventional photovoltaic and reactor power systems. These high power satellites can play a vital role in assuring availability of universally accessible, wide bandwidth communications, for high definition TV, super computer networks and other services. Satellites are ideally suited to provide the wide bandwidths and data rates required and are unique in the ability to provide services directly to the users. As new or relocated markets arise, satellites offer a flexibility that conventional distribution services cannot match, and it is no longer necessary to be near population centers to take advantage of the telecommunication revolution. The geopolitical implications of these substantially enhanced communications capabilities can be significant.

  11. Observational demonstration of a high image rejection SIS mixer receiver using a new waveguide filter at 230 GHz

    Science.gov (United States)

    Hasegawa, Yutaka; Asayama, Shinichiro; Harada, Ryohei; Tokuda, Kazuki; Kimura, Kimihiro; Ogawa, Hideo; Onishi, Toshikazu

    2017-12-01

    A new sideband separation method was developed for use in millimeter-/submillimeter-band radio receivers using a novel waveguide frequency separation filter (FSF), which consists of two branch line hybrid couplers and two waveguide high-pass filters. The FSF was designed to allow the radio frequency (RF) signal to pass through to an output port when the frequency is higher than a certain value (225 GHz), and to reflect the RF signal back to another output port when the frequency is lower. The FSF is connected to two double sideband superconductor-insulator-superconductor (SIS) mixers, and an image rejection ratio (IRR) is determined by the FSF characteristics. With this new sideband separation method, we can achieve good and stable IRR without the balancing two SIS mixers such as is necessary for conventional sideband-separating SIS mixers. To demonstrate the applicability of this method, we designed and developed an FSF for simultaneous observations of the J = 2-1 rotational transition lines of three CO isotopes (12CO, 13CO, and C18O): the 12CO line is in the upper sideband and the others are in the lower sideband with an intermediate-frequency range of 4-8 GHz at the radio frequency of 220/230 GHz. This FSF was then installed in the receiver system of the 1.85 m radio telescope of Osaka Prefecture University, and was used during the 2014 observation season. The observation results indicate that the IRR of the proposed receiver is 25 dB or higher for the 12CO line, and no significant fluctuation larger than 1 dB in the IRR was observed throughout the season. These results demonstrate the practical utility of the FSF receiver for observations like extensive molecular cloud surveys in specified lines with a fixed frequency setting.

  12. A high power, tunable free electron maser for fusion

    Energy Technology Data Exchange (ETDEWEB)

    Urbanus, W.H.; Bratman, V.L.; Bongers, W.A.; Caplan, M.; Denisov, G.G.; Geer, C.A.J. van der; Manintveld, P.; Militsyn, B.; Oomens, A.A.M.; Poelman, A.J.; Plomp, J.; Pluygers, J.; Savilov, A.V.; Smeets, P.H.M.; Sterk, A.B.; Verhoeven, A.G.A

    2001-01-01

    The Fusion-FEM experiment, a high-power, electrostatic free-electron maser being built at the FOM-Institute for Plasma Physics 'Rijnhuizen', is operated at various frequencies. So far, experiments were done without a depressed collector, and the pulse length was limited to 12 {mu}s. Nevertheless, many aspects of generation of mm-wave power have been explored, such as the dependency on the electron beam energy and beam current, and cavity settings such as the feedback coefficient. An output power of 730 kW at 206 GHz is generated with a 7.2 A, 1.77 MeV electron beam, and 360 kW at 167 GHz is generated with a 7.4 A, 1.61 MeV electron beam. It is shown experimentally and by simulations that, depending on the electron beam energy, the FEM can operate in single-frequency regime. The next step of the FEM experiment is to reach a pulse length of 100 ms. The major part of the beam line, the high voltage systems, and the collector have been completed. The undulator and mm-wave cavity are now at high voltage (2 MV). The new mm-wave transmission line, which transports the mm-wave output power from the high-voltage terminal to ground and outside the pressure tank, has been tested at low power.

  13. High Power Orbit Transfer Vehicle

    National Research Council Canada - National Science Library

    Gulczinski, Frank

    2003-01-01

    ... from Virginia Tech University and Aerophysics, Inc. to examine propulsion requirements for a high-power orbit transfer vehicle using thin-film voltaic solar array technologies under development by the Space Vehicles Directorate (dubbed PowerSail...

  14. Fabrication of a 77 GHz Rotman Lens on a High Resistivity Silicon Wafer Using Lift-Off Process

    Directory of Open Access Journals (Sweden)

    Ali Attaran

    2014-01-01

    Full Text Available Fabrication of a high resistivity silicon based microstrip Rotman lens using a lift-off process has been presented. The lens features 3 beam ports, 5 array ports, 16 dummy ports, and beam steering angles of ±10 degrees. The lens was fabricated on a 200 μm thick high resistivity silicon wafer and has a footprint area of 19.7 mm × 15.6 mm. The lens was tested as an integral part of a 77 GHz radar where a tunable X band source along with an 8 times multiplier was used as the RF source and the resulting millimeter wave signal centered at 77 GHz was radiated through a lens-antenna combination. A horn antenna with a downconverter harmonic mixer was used to receive the radiated signal and display the received signal in an Advantest R3271A spectrum analyzer. The superimposed transmit and receive signal in the spectrum analyzer showed the proper radar operation confirming the Rotman lens design.

  15. High Efficiency Power Converter for Low Voltage High Power Applications

    DEFF Research Database (Denmark)

    Nymand, Morten

    The topic of this thesis is the design of high efficiency power electronic dc-to-dc converters for high-power, low-input-voltage to high-output-voltage applications. These converters are increasingly required for emerging sustainable energy systems such as fuel cell, battery or photo voltaic based...

  16. High power excimer laser

    International Nuclear Information System (INIS)

    Oesterlin, P.; Muckenheim, W.; Basting, D.

    1988-01-01

    Excimer lasers emitting more than 200 W output power are not commercially available. A significant increase requires new technological efforts with respect to both the gas circulation and the discharge system. The authors report how a research project has yielded a laser which emits 0.5 kW at 308 nm when being UV preionized and operated at a repetition rate of 300 Hz. The laser, which is capable of operating at 500 Hz, can be equipped with an x-ray preionization module. After completing this project 1 kW output power will be available

  17. Optimum concentric circular array antenna with high gain and side lobe reduction at 5.8 GHz

    Science.gov (United States)

    Zaid, Mohammed; Rafiqul Islam, Md; Habaebi, Mohamed H.; Zahirul Alam, AHM; Abdullah, Khaizuran

    2017-11-01

    The significance of high gain directional antennas stems from the need to cope up with the everyday progressing wireless communication systems. Due to low gain of the widely used microstrip antenna, combining multiple antennas in proper geometry increases the gain with good directive property. Over other array forms, this paper uses concentric circular array configuration for its compact structure and inherent symmetry in azimuth. This proposed array is composed of 9 elements on FR-4 substrate, which is designed for WLAN applications at 5.8GHz. Antenna Magus software is used for synthesis, while CST software is used for optimization. The proposed array is designed with optimum inter-element spacing and number of elements achieving a high directional gain of 15.7 dB compared to 14.2 dB of available literature, with a high reduction in side lobe level of -17.6 dB.

  18. High average power supercontinuum sources

    Indian Academy of Sciences (India)

    The physical mechanisms and basic experimental techniques for the creation of high average spectral power supercontinuum sources is briefly reviewed. We focus on the use of high-power ytterbium-doped fibre lasers as pump sources, and the use of highly nonlinear photonic crystal fibres as the nonlinear medium.

  19. Generation of strong electromagnetic power at 35 GHz from the interaction of a resonant cavity with a relativistic electron beam generated by a free electron laser

    International Nuclear Information System (INIS)

    Lefevre, Thibaut

    2000-01-01

    The next generation of electron-positron linear colliders must reach the TeV energy range. For this, one requires an adequate RF power source to feed the accelerating cavities of the collider. One way to generate this source is to use the Two Beam Accelerator concept in which the RF power is produced in resonant cavities driven by an intense bunched beam. In this thesis, I present the experimental results obtained at the CEA/CESTA using an electron beam generated by an induction linac. First, some studies were performed with the LELIA induction linac (2.2 MeV, 1 kA, 80 ns) using a Free Electron Laser (FEL) as a buncher at 35 GHz. A second part relates the experiment made with the PIVAIR induction linac (7 MeV, 1 kA, 80 ns) in order to measure the RF power extracted from a resonant cavity at 35 GHz, which is driven by the bunches produced in the FEL. One can also find a simple theoretical modeling of the beam-cavity interaction, and the numerical results dealing with the design of the cavity we tested. (author) [fr

  20. A 3.1-4.8 GHz transmitter with a high frequency divider in 0.18 μm CMOS for OFDM-UWB

    International Nuclear Information System (INIS)

    Zheng Renliang; Ren Junyan; Li Wei; Li Ning

    2009-01-01

    A fully integrated low power RF transmitter for a WiMedia 3.1-4.8 GHz multiband orthogonal frequency division multiplexing ultra-wideband system is presented. With a separate transconductance stage, the quadrature up-conversion modulator achieves high linearity with low supply voltage. The co-design of different resonant frequencies of the modulator and the differential to single (D2S) converter ensures in-band gain flatness. By means of a series inductor peaking technique, the D2S converter obtains 9 dB more gain without extra power consumption. A divided-by-2 divider is used for carrier signal generation. The measurement results show an output power between -10.7 and -3.1 dBm with 7.6 dB control range, an OIP3 up to 12 dBm, a sideband rejection of 35 dBc and a carrier rejection of 30 dBc. The ESD protected chip is fabricated in the Jazz 0.18 μm RF CMOS process with an area of 1.74 mm 2 and only consumes 32 mA current (at 1.8 V) including the test associated parts. (semiconductor integrated circuits)

  1. A 3.1-4.8 GHz transmitter with a high frequency divider in 0.18 {mu}m CMOS for OFDM-UWB

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Renliang; Ren Junyan; Li Wei; Li Ning, E-mail: jyren@fudan.edu.c [Micro/Nano Science and Innovation Platform, State Key Laboratory of ASIC and System, Fudan University, Shanghai 201203 (China)

    2009-12-15

    A fully integrated low power RF transmitter for a WiMedia 3.1-4.8 GHz multiband orthogonal frequency division multiplexing ultra-wideband system is presented. With a separate transconductance stage, the quadrature up-conversion modulator achieves high linearity with low supply voltage. The co-design of different resonant frequencies of the modulator and the differential to single (D2S) converter ensures in-band gain flatness. By means of a series inductor peaking technique, the D2S converter obtains 9 dB more gain without extra power consumption. A divided-by-2 divider is used for carrier signal generation. The measurement results show an output power between -10.7 and -3.1 dBm with 7.6 dB control range, an OIP3 up to 12 dBm, a sideband rejection of 35 dBc and a carrier rejection of 30 dBc. The ESD protected chip is fabricated in the Jazz 0.18 {mu}m RF CMOS process with an area of 1.74 mm{sup 2} and only consumes 32 mA current (at 1.8 V) including the test associated parts. (semiconductor integrated circuits)

  2. Design of ultralow power receiver front-ends for 2.4 GHz wireless sensor network applications

    International Nuclear Information System (INIS)

    Zhang Meng; Li Zhiqun; Wang Zengqi; Wu Chenjian; Chen Liang

    2014-01-01

    This paper presents the design of an ultralow power receiver front-end designed for a wireless sensor network (WSN) in a 0.18 μm CMOS process. The author designs two front-ends working in the saturation region and the subthreshold region respectively. The front-ends contain a two-stage cross-coupling cascaded common-gate (CG) LNA and a quadrature Gilbert IQ mixer. The measured conversion gain is variable with high gain at 24 dB and low gain at 7 dB for the saturation one, and high gain at 22 dB and low gain at 5 dB for the subthreshold one. The noise figure (NF) at high gain mode is 5.1 dB and 6.3 dB for each. The input 1 dB compression point (IP1dB) at low gain mode is about −6 dBm and −3 dBm for each. The front-ends consume about 2.1 mA current from 1.8 V power supply for the saturation one and 1.3 mA current for the subthreshold one. The measured results show that, comparing with the power consumption saving, it is worth making sacrifices on the performance for using the subthreshold technology. (semiconductor integrated circuits)

  3. Research on calorimeter for high-power microwave measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Hu; Ning, Hui; Yang, Wensen; Tian, Yanmin; Xiong, Zhengfeng; Yang, Meng; Yan, Feng; Cui, Xinhong [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi’an, Shaanxi 710024 (China)

    2015-12-15

    Based on measurement of the volume increment of polar liquid that is a result of heating by absorbed microwave energy, two types of calorimeters with coaxial capacitive probes for measurement of high-power microwave energy are designed in this paper. The first is an “inline” calorimeter, which is placed as an absorbing load at the end of the output waveguide, and the second is an “offline” calorimeter that is placed 20 cm away from the radiation horn of the high-power microwave generator. Ethanol and high density polyethylene are used as the absorbing and housing materials, respectively. Results from both simulations and a “cold test” on a 9.3 GHz klystron show that the “inline” calorimeter has a measurement range of more than 100 J and an energy absorption coefficient of 93%, while the experimental results on a 9.3 GHz relativistic backward-wave oscillator show that the device’s power capacity is approximately 0.9 GW. The same experiments were also carried out for the “offline” calorimeter, and the results indicate that it can be used to eliminate the effects of the shock of the solenoid on the measurement curves and that the device has a higher power capacity of 2.5 GW. The results of the numerical simulations, the “cold tests,” and the experiments show good agreement.

  4. Research on calorimeter for high-power microwave measurements.

    Science.gov (United States)

    Ye, Hu; Ning, Hui; Yang, Wensen; Tian, Yanmin; Xiong, Zhengfeng; Yang, Meng; Yan, Feng; Cui, Xinhong

    2015-12-01

    Based on measurement of the volume increment of polar liquid that is a result of heating by absorbed microwave energy, two types of calorimeters with coaxial capacitive probes for measurement of high-power microwave energy are designed in this paper. The first is an "inline" calorimeter, which is placed as an absorbing load at the end of the output waveguide, and the second is an "offline" calorimeter that is placed 20 cm away from the radiation horn of the high-power microwave generator. Ethanol and high density polyethylene are used as the absorbing and housing materials, respectively. Results from both simulations and a "cold test" on a 9.3 GHz klystron show that the "inline" calorimeter has a measurement range of more than 100 J and an energy absorption coefficient of 93%, while the experimental results on a 9.3 GHz relativistic backward-wave oscillator show that the device's power capacity is approximately 0.9 GW. The same experiments were also carried out for the "offline" calorimeter, and the results indicate that it can be used to eliminate the effects of the shock of the solenoid on the measurement curves and that the device has a higher power capacity of 2.5 GW. The results of the numerical simulations, the "cold tests," and the experiments show good agreement.

  5. A 750MHz and a 8GHz High Bandwidth Digital FFT Spectrometer, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The scope of this project is to to develop a wide bandwidth, low power, and compact single board digital Fast Fourier Transform spectrometer (FFTS) optimized for the...

  6. The MAT/TOCO Measurement of the Angular Power Spectrum of the Cosmic Microwave Background at 30 and 40 GHz

    Science.gov (United States)

    Nolta, M. R.; Devlin, M. J.; Dorwart, W. B.; Miller, A. D.; Page, L. A.; Puchalla, J.; Torbet, E.; Tran, H. T.

    2003-11-01

    We present a measurement of the angular spectrum of the cosmic microwave background from l=26 to 225 from the 30 and 40 GHz channels of the MAT/TOCO experiment based on two seasons of observations. At comparable frequencies, the data extend to a lower l than the recent Very Small Array and DASI results. After accounting for known foreground emission in a self-consistent analysis, a rise from the Sachs-Wolfe plateau to a peak of δTl~80 μK near l~200 is observed.

  7. State-of-the-art of high power gyro-devices and free electron masers

    International Nuclear Information System (INIS)

    Thumm, M.

    1993-10-01

    At present, gyrotron oscillators are mainly used as high power millimeter wave sources for electron cyclotron resonance heating (ECRH) and diagnostics of magnetically confined plasmas for generation of energy by controlled thermonuclear fusion. 140 GHz gyrotrons with output power P out = 0.58 MW, pulse length τ = 2.0 s and efficiency η = 34% are commercially available. Diagnostic gyrotrons deliver P out = 40 kW with τ = 40 μs at frequencies up to 650 GHz (η ≥ 4%). Recently, gyrotron oscillators have also been successfully used in material processing and plasma chemistry. Such technological applications require gyrotrons with the following parameters: f ≥ 28 GHz, P out = 10-30 kW, CW, η ≥ 30%. This paper reports on achievements and problems related to the development of very high power mm-wave gyrotrons for long pulse or CW operation and describes the microwave technological pecularities of the different development steps. In addition, this work gives a short overview of the present development of gyrotrons for technological applications, quasi-optical gyrotrons, cyclotron autoresonance masers (CARMs), gyro-klystrons, gyro-TWT amplifiers, gyro-BWO's and free electron masers (FEMs). The most impressive FEM output parameters are: P out = 2 GW, τ = 20 ns, η = 13% at 140 GHz (LLNL) and P out = 15 kW, τ = 20 μs, η = 5% in the range from 120 to 900 GHz (UCSB). (orig.) [de

  8. HIGH-TIME-RESOLUTION MEASUREMENTS OF THE POLARIZATION OF THE CRAB PULSAR AT 1.38 GHz

    Energy Technology Data Exchange (ETDEWEB)

    Słowikowska, Agnieszka [Kepler Institute of Astronomy, University of Zielona Góra, Lubuska 2, 65-265 Zielona Góra (Poland); Stappers, Benjamin W. [Jodrell Bank Centre for Astrophysics, University of Manchester, Manchester M13 9PL (United Kingdom); Harding, Alice K. [Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); O' Dell, Stephen L.; Elsner, Ronald F.; Weisskopf, Martin C. [Astrophysics Office, NASA Marshall Space Flight Center, ZP12, Huntsville, AL 35812 (United States); Van der Horst, Alexander J. [Astronomical Institute, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands)

    2015-01-20

    Using the Westerbork Synthesis Radio Telescope, we obtained high-time-resolution measurements of the full polarization of the Crab pulsar. At a resolution of 1/8192 of the 34 ms pulse period (i.e., 4.1 μs), the 1.38 GHz linear-polarization measurements are in general agreement with previous lower-time-resolution 1.4 GHz measurements of linear polarization in the main pulse (MP), in the interpulse (IP), and in the low-frequency component (LFC). We find the MP and IP to be linearly polarized at about 24% and 21% with no discernible difference in polarization position angle. However, contrary to theoretical expectations and measurements in the visible, we find no evidence for significant variation (sweep) in the polarization position angle over the MP, the IP, or the LFC. We discuss the implications, which appear to be in contradiction to theoretical expectations. We also detect weak circular polarization in the MP and IP, and strong (≈20%) circular polarization in the LFC, which also exhibits very strong (≈98%) linear polarization at a position angle of 40° from that of the MP or IP. The properties are consistent with the LFC, which is a low-altitude component, and the MP and IP, which are high-altitude caustic components. Current models for the MP and IP emission do not readily account for the absence of pronounced polarization changes across the pulse. We measure IP and LFC pulse phases relative to the MP consistent with recent measurements, which have shown that the phases of these pulse components are evolving with time.

  9. 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.

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

    KAUST Repository

    Arsalan, Muhammad; Ouda, Mahmoud H.; Marnat, Loic; Ahmad, Talha Jamal; Shamim, Atif; Salama, Khaled N.

    2013-01-01

    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. High-powered manoeuvres

    CERN Multimedia

    Anaïs Schaeffer

    2013-01-01

    This week, CERN received the latest new transformers for the SPS. Stored in pairs in 24-tonne steel containers, these transformers will replace the old models, which have been in place since 1981.     The transformers arrive at SPS's access point 4 (BA 4). During LS1, the TE-EPC Group will be replacing all of the transformers for the main converters of the SPS. This renewal campaign is being carried out as part of the accelerator consolidation programme, which began at the start of April and will come to an end in November. It involves 80 transformers: 64 with a power of 2.6 megavolt-amperes (MVA) for the dipole magnets, and 16 with 1.9 MVA for the quadrupoles. These new transformers were manufactured by an Italian company and are being installed outside the six access points of the SPS by the EN-HE Group, using CERN's 220-tonne crane. They will contribute to the upgrade of the SPS, which should thus continue to operate as the injector for the LHC until 2040....

  12. High-power fiber lasers for photocathode electron injectors

    Directory of Open Access Journals (Sweden)

    Zhi Zhao

    2014-05-01

    Full Text Available Many new applications for electron accelerators require high-brightness, high-average power beams, and most rely on photocathode-based electron injectors as a source of electrons. To achieve such a photoinjector, one requires both a high-power laser system to produce the high average current beam, and also a system at reduced repetition rate for electron beam diagnostics to verify high beam brightness. Here we report on two fiber laser systems designed to meet these specific needs, at 50 MHz and 1.3 GHz repetition rate, together with pulse pickers, second harmonic generation, spatiotemporal beam shaping, intensity feedback, and laser beam transport. The performance and flexibility of these laser systems have allowed us to demonstrate electron beam with both low emittance and high average current for the Cornell energy recovery linac.

  13. A high frequency, high power CARM proposal for the DEMO ECRH system

    International Nuclear Information System (INIS)

    Mirizzi, Francesco; Spassovsky, Ivan; Ceccuzzi, Silvio; Dattoli, Giuseppe; Di Palma, Emanuele; Doria, Andrea; Gallerano, Gianpiero; Lampasi, Alessandro; Maffia, Giuseppe; Ravera, GianLuca; Sabia, Elio; Tuccillo, Angelo Antonio; Zito, Pietro

    2015-01-01

    Highlights: • ECRH system for DEMO. • Cyclotron Auto-Resonance Maser (CARM) devices. • Relativistic electron beams. • Bragg reflectors. • High voltage pulse modulators. - Abstract: ECRH&CD systems are extensively used on tokamak plasmas due to their capability of highly tailored power deposition, allowing very localised heating and non-inductive current drive, useful for MHD and profiles control. The high electron temperatures expected in DEMO will require ECRH systems with operating frequency in the 200–300 GHz range, equipped with a reasonable number of high power (P ≥ 1 MW) CW RF sources, for allowing central RF power deposition. In this frame the ENEA Fusion Department (Frascati) is coordinating a task force aimed at the study and realisation of a suitable high power, high frequency reliable source.

  14. A high frequency, high power CARM proposal for the DEMO ECRH system

    Energy Technology Data Exchange (ETDEWEB)

    Mirizzi, Francesco, E-mail: francesco.mirizzi@enea.it [Consorzio CREATE, Via Claudio 21, I-80125 Napoli (Italy); Spassovsky, Ivan [Unità Tecnica Applicazioni delle Radiazioni – ENEA, C.R. Frascati, via E. Fermi 45, I-00044 Frascati (Italy); Ceccuzzi, Silvio [Unità Tecnica Fusione – ENEA C. R. Frascati, via E. Fermi 45, 00044 Frascati, Roma (Italy); Dattoli, Giuseppe; Di Palma, Emanuele; Doria, Andrea; Gallerano, Gianpiero [Unità Tecnica Applicazioni delle Radiazioni – ENEA, C.R. Frascati, via E. Fermi 45, I-00044 Frascati (Italy); Lampasi, Alessandro; Maffia, Giuseppe; Ravera, GianLuca [Unità Tecnica Fusione – ENEA C. R. Frascati, via E. Fermi 45, 00044 Frascati, Roma (Italy); Sabia, Elio [Unità Tecnica Applicazioni delle Radiazioni – ENEA, C.R. Frascati, via E. Fermi 45, I-00044 Frascati (Italy); Tuccillo, Angelo Antonio; Zito, Pietro [Unità Tecnica Fusione – ENEA C. R. Frascati, via E. Fermi 45, 00044 Frascati, Roma (Italy)

    2015-10-15

    Highlights: • ECRH system for DEMO. • Cyclotron Auto-Resonance Maser (CARM) devices. • Relativistic electron beams. • Bragg reflectors. • High voltage pulse modulators. - Abstract: ECRH&CD systems are extensively used on tokamak plasmas due to their capability of highly tailored power deposition, allowing very localised heating and non-inductive current drive, useful for MHD and profiles control. The high electron temperatures expected in DEMO will require ECRH systems with operating frequency in the 200–300 GHz range, equipped with a reasonable number of high power (P ≥ 1 MW) CW RF sources, for allowing central RF power deposition. In this frame the ENEA Fusion Department (Frascati) is coordinating a task force aimed at the study and realisation of a suitable high power, high frequency reliable source.

  15. Autonomously managed high power systems

    International Nuclear Information System (INIS)

    Weeks, D.J.; Bechtel, R.T.

    1985-01-01

    The need for autonomous power management capabilities will increase as the power levels of spacecraft increase into the multi-100 kW range. The quantity of labor intensive ground and crew support consumed by the 9 kW Skylab cannot be afforded in support of a 75-300 kW Space Station or high power earth orbital and interplanetary spacecraft. Marshall Space Flight Center is managing a program to develop necessary technologies for high power system autonomous management. To date a reference electrical power system and automation approaches have been defined. A test facility for evaluation and verification of management algorithms and hardware has been designed with the first of the three power channel capability nearing completion

  16. High-throughput and low-latency 60GHz small-cell network architectures over radio-over-fiber technologies

    Science.gov (United States)

    Pleros, N.; Kalfas, G.; Mitsolidou, C.; Vagionas, C.; Tsiokos, D.; Miliou, A.

    2017-01-01

    Future broadband access networks in the 5G framework will need to be bilateral, exploiting both optical and wireless technologies. This paper deals with new approaches and synergies on radio-over-fiber (RoF) technologies and how those can be leveraged to seamlessly converge wireless technology for agility and mobility with passive optical networks (PON)-based backhauling. The proposed convergence paradigm is based upon a holistic network architecture mixing mm-wave wireless access with photonic integration, dynamic capacity allocation and network coding schemes to enable high bandwidth and low-latency fixed and 60GHz wireless personal area communications for gigabit rate per user, proposing and deploying on top a Medium-Transparent MAC (MT-MAC) protocol as a low-latency bandwidth allocation mechanism. We have evaluated alternative network topologies between the central office (CO) and the access point module (APM) for data rates up to 2.5 Gb/s and SC frequencies up to 60 GHz. Optical network coding is demonstrated for SCM-based signaling to enhance bandwidth utilization and facilitate optical-wireless convergence in 5G applications, reporting medium-transparent network coding directly at the physical layer between end-users communicating over a RoF infrastructure. Towards equipping the physical layer with the appropriate agility to support MT-MAC protocols, a monolithic InP-based Remote Antenna Unit optoelectronic PIC interface is shown that ensures control over the optical resource allocation assisting at the same time broadband wireless service. Finally, the MT-MAC protocol is analysed and simulation and analytical theoretical results are presented that are found to be in good agreement confirming latency values lower than 1msec for small- to mid-load conditions.

  17. 34 GHz, 45 MW pulsed magnicon

    International Nuclear Information System (INIS)

    Nezhevenko, Oleg A.; LaPointe, Michael A.; Yakovlev, Vyacheslav P.; Hirshfield, Jay L.; Serdobintsev, Gennady V.; Kuznetsov, Gennady I.; Persov, Boris Z.; Fix, Alexander

    2002-01-01

    A high efficiency, high power magnicon at 34.272 GHz has been designed and built as a microwave source to develop RF technology for a future multi-TeV electron-positron linear collider. The tube is designed to provide a peak output power of ∼45 MW in a 1 microsecond pulse, with a gain of 55 dB, using a 500 kV, 220 A, 1 mm-diameter electron beam. The status of the tube itself as well as the near-term experimental program is presented

  18. Monotron and azimuthally corrugated: application to the high power microwaves generation

    International Nuclear Information System (INIS)

    Castro, Pedro Jose de

    2003-01-01

    The present document reports the activity of construction and initial operation of 6.7 GHz operation for high power microwave generation, the study on cylindrical resonators with azimuthally corrugated cross section, the determination of electrical conductivity of metallic materials and development of dielectric resonators for telecommunication applications

  19. Ka-Band AlGaN/GaN HEMT high power and driver amplifier MMICs

    NARCIS (Netherlands)

    Heijningen, M. van; Vliet, F.E. van; Quay, R.; Raay, F. van; Kiefer, R.; Mueller, S.; Krausse, D.; Seelmann-Eggebert, M.; Mikulla, M.; Schlechtweg, M.

    2005-01-01

    In this paper the MMIC technology, design and characterization of a high power amplifier and driver amplifier MMIC at 30 GHz in AlGaN/GaN HEMT technology are presented. The MMICs are designed using CPW technology on a 390 μm thick SiC substrate. The measured small-signal gain of the driver is 14 dB

  20. An High Performance Integrated Balun for 60 GHz Application in 65nm CMOS Technology

    OpenAIRE

    Ercoli , Mariano; Kraemer , Michael; Dragomirescu , Daniela; Plana , Robert

    2010-01-01

    International audience; This paper shows a new design approach that allows to integrate an efficient balun into mm-wave radio frequency integrated circuits (RFIC). The proposed device is an evolution of the simple transformer. Thanks to the modification on the device's shape, the performance increases considerably, maintaining limited dimensions. The proposed balun shows a very good power division with only 0.5 dB of maximum amplitude imbalance within the whole band of interest and less than ...

  1. EURISOL High Power Targets

    CERN Document Server

    Kadi, Y; Lindroos, M; Ridikas, D; Stora, T; Tecchio, L; CERN. Geneva. BE Department

    2009-01-01

    Modern Nuclear Physics requires access to higher yields of rare isotopes, that relies on further development of the In-flight and Isotope Separation On-Line (ISOL) production methods. The limits of the In-Flight method will be applied via the next generation facilities FAIR in Germany, RIKEN in Japan and RIBF in the USA. The ISOL method will be explored at facilities including ISAC-TRIUMF in Canada, SPIRAL-2 in France, SPES in Italy, ISOLDE at CERN and eventually at the very ambitious multi-MW EURISOL facility. ISOL and in-flight facilities are complementary entities. While in-flight facilities excel in the production of very short lived radioisotopes independently of their chemical nature, ISOL facilities provide high Radioisotope Beam (RIB) intensities and excellent beam quality for 70 elements. Both production schemes are opening vast and rich fields of nuclear physics research. In this article we will introduce the targets planned for the EURISOL facility and highlight some of the technical and safety cha...

  2. A novel NiZn ferrite integrated magnetic solenoid inductor with a high quality factor at 0.7–6 GHz

    Directory of Open Access Journals (Sweden)

    Xinjun Wang

    2017-05-01

    Full Text Available Integrated inductor is one of the fundamental components and has been widely used in radio frequency integrated circuits (RFICs. It has been challenging to achieve simultaneously high inductance and quality factor, particularly at GHz frequencies. In this work, we reported a novel integrated solenoid inductor with a magnetic NiZn ferrite as the core material, which was deposited by a low-cost spin spray technique. These integrated inductors showed a significant improvement in both inductance and quality factor at GHz frequencies over their air core counterparts. A stable inductance was observed within a wide frequency ranged from 700 MHz to 6 GHz. The peak value of quality factor reached 23, a relatively higher value not reported for solenoid inductors up to date. Our results indicate that the integrated inductor are promising for applications in RFICs.

  3. Applications of high power microwaves

    International Nuclear Information System (INIS)

    Benford, J.; Swegle, J.

    1993-01-01

    The authors address a number of applications for HPM technology. There is a strong symbiotic relationship between a developing technology and its emerging applications. New technologies can generate new applications. Conversely, applications can demand development of new technological capability. High-power microwave generating systems come with size and weight penalties and problems associated with the x-radiation and collection of the electron beam. Acceptance of these difficulties requires the identification of a set of applications for which high-power operation is either demanded or results in significant improvements in peRFormance. The authors identify the following applications, and discuss their requirements and operational issues: (1) High-energy RF acceleration; (2) Atmospheric modification (both to produce artificial ionospheric mirrors for radio waves and to save the ozone layer); (3) Radar; (4) Electronic warfare; and (5) Laser pumping. In addition, they discuss several applications requiring high average power than border on HPM, power beaming and plasma heating

  4. Modular High Voltage Power Supply

    Energy Technology Data Exchange (ETDEWEB)

    Newell, Matthew R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-18

    The goal of this project is to develop a modular high voltage power supply that will meet the needs of safeguards applications and provide a modular plug and play supply for use with standard electronic racks.

  5. A 60-GHz energy harvesting module with on-chip antenna and switch for co-integration with ULP radios in 65-nm CMOS with fully wireless mm-wave power transfer measurement

    NARCIS (Netherlands)

    Gao, H.; Matters - Kammerer, M.; Harpe, P.J.A.; Milosevic, D.; Roermund, van A.H.M.; Linnartz, J.P.M.G.; Baltus, P.G.M.

    2014-01-01

    In this paper the architecture and performance of a co-integrated 60 GHz on-chip wireless energy harvester and ultra-low power (ULP) radio in 65-nm CMOS are discussed. Integration of an on-chip antenna with wireless power receiver and wireless data transfer module is the crucial next step to achieve

  6. Design of a high speed, high resolution thermometry system for 1.5 GHz superconducting radio frequency cavities

    Science.gov (United States)

    Knobloch, Jens; Muller, Henry; Padamsee, Hasan

    1994-11-01

    Presented in this paper are the description and the test results of a new stationary thermometry system used to map the temperature of the outer surface of 1.5 GHz superconducting single-cell cavities during operation at 1.6 K. The system comprises 764 removable carbon thermometers whose signals are multiplexed and scanned by a Macintosh computer. A complete temperature map can be obtained in as little as 0.1 s at a temperature resolution of about 0.2 mK. Alternatively, it has been demonstrated that if the acquisition time is increased to several seconds, then a temperature resolution on the order of 30 μK is possible. To our knowledge, these are the fastest acquisition times so far achieved with L-band cavities at these resolutions.

  7. DATA transmission by 2.4 GHz radio frequency and LAN from Nuclear Power Plant to office

    International Nuclear Information System (INIS)

    Tsuji, Kenji; Masuda, Ryota; Hukui, Takuya

    2011-01-01

    Additional monitoring is occasionally done on suspicious equipment such as pumps, motors, valves and so on, when monitoring parameters are different from normal operation in Nuclear Power Plant. If the suspicious equipment is located in high radiation area, it is hard to arrange for the additional monitoring. So, wireless data transmission system is desired. And maintenance persons desire to watch the additional monitoring data in their office on P.C. We can enable to transfer the desired live data from sensors in NPP to the maintenance person's office, using by ZigBee system connected to LAN. In order to enlarge the operating term, the battery for sensors is switched on or off by the signal related to sleeping function on ZigBee sensor-terminal. (author)

  8. High field tests of 1.3 GHz niobium superconducting cavities

    International Nuclear Information System (INIS)

    Kako, Eiji; Noguchi, Shuichi; Ono, Masaaki

    1993-01-01

    Four single-cell cavities prepared by various surface treatments have been tested repeatedly since 1991. A maximum accelerating gradient of 25.1 MV/m with a high Q 0 value of ∼10 10 was successfully achieved after heat treatment at 1400degC. A temperature mapping system with a high thermal sensitivity under superfluid helium was developed to understand phenomena limiting a maximum accelerating gradient. The cavity performances and the phenomena at high fields are reported in this paper. (author)

  9. High-power corrugates waveguide components for mm-wave fusion heating systems

    International Nuclear Information System (INIS)

    Olstad, R.A.; Doane, J.L.; Moeller, C.P.; O'Neill, R.C.; Di Martino, M.

    1996-10-01

    Considerable progress has been made over the last year in the U.S., Japan, Russia, and Europe in developing high power long pulse gyrotrons for fusion plasma heating and current drive. These advanced gyrotrons typically operate at a frequency in the range 82 GHz to 170 GHz at nearly megawatt power levels for pulse lengths up to 5 s. To take advantage of these new microwave sources for fusion research, new and improved transmission line components are needed to reliably transmit microwave power to plasmas with minimal losses. Over the last year, General Atomics and collaborating companies (Spinner GmbH in Europe and Toshiba Corporation in Japan) have developed a wide variety of new components which meet the demanding power, pulse length, frequency, and vacuum requirements for effective utilization of the new generation of gyrotrons. These components include low-loss straight corrugated waveguides, miter bends, miter bend polarizers, power monitors, waveguide bellows, de breaks, waveguide switches, dummy loads, and distributed windows. These components have been developed with several different waveguide diameters (32, 64, and 89 mm) and frequency ranges (82 GHz to 170 GHz). This paper describes the design requirements of selected components and their calculated and measured performance characteristics

  10. Integrated 60GHz RF beamforming in CMOS

    CERN Document Server

    Yu, Yikun; van Roermund, Arthur H M

    2011-01-01

    ""Integrated 60GHz RF Beamforming in CMOS"" describes new concepts and design techniques that can be used for 60GHz phased array systems. First, general trends and challenges in low-cost high data-rate 60GHz wireless system are studied, and the phased array technique is introduced to improve the system performance. Second, the system requirements of phase shifters are analyzed, and different phased array architectures are compared. Third, the design and implementation of 60GHz passive and active phase shifters in a CMOS technology are presented. Fourth, the integration of 60GHz phase shifters

  11. Production of highly charged heavy ions by 18 GHz superconducting electron cyclotron resonance at Research Center for Nuclear Physics.

    Science.gov (United States)

    Yorita, Tetsuhiko; Hatanaka, Kichiji; Fukuda, Mitsuhiro; Kibayashi, Mitsuru; Morinobu, Shunpei; Okamura, Hiroyuki; Tamii, Atsushi

    2010-02-01

    An 18 GHz superconducting electron cyclotron resonance ion source has been installed as a subject of the azimuthally varying field cyclotron upgrade project (K. Hatanaka et al., in Proceedings of the 17th International Conference on Cyclotrons and Their Applications, Tokyo, Japan, 18-22 October 2004, pp. 115-117), in order to increase beam currents and to extend the variety of ions. The production development of several ions has been performed since 2006 and some of them have already been used for user experiments [T. Yorita et al., Rev. Sci. Instrum. 79, 02A311 (2008)]. Further optimizations for each component such as the material of plasma electrode, material, and shape of bias probe and mirror field have been continued and more intense ion beams have been obtained for O, N, and Ar. For the purpose of obtaining highly charged Xe with several microamperes, the optimization of position and shape of plasma electrode and bias disk has also been done and highly charged Xe(32+) beam has been obtained successfully.

  12. High-Power Ka-Band Window and Resonant Ring

    International Nuclear Information System (INIS)

    Jay L. Hirshfield

    2006-01-01

    A stand-alone 200 MW rf test station is needed for carrying out development of accelerator structures and components for a future high-gradient multi-TeV collider, such as CLIC. A high-power rf window is needed to isolate the test station from a structure element under test. This project aimed to develop such a window for use at a frequency in the range 30-35 GHz, and to also develop a high-power resonant ring for testing the window. During Phase I, successful conceptual designs were completed for the window and the resonant ring, and cold tests of each were carried out that confirmed the designs

  13. Recent operating experience with Varian 70 GHz and 140 GHz gyrotrons

    International Nuclear Information System (INIS)

    Felch, K.; Bier, R.; Fox, L.; Huey, H.; Ives, L.; Jory, H.; Lopez, N.; Shively, J.; Spang, S.

    1985-01-01

    The design features and initial test results of Varian 70 GHz and 140 GHz CW gyrotrons are presented. The first experimental 140 GHz tube has achieved an output power of 102 kW at 24% efficiency under pulsed conditions in the desired TE 031 0 cavity mode. Further tests aimed at achieving the design goal of 100 kW CW are currently underway. The 70 GHz tube has achieved an output power of 200 kW under pulsed conditions and possesses a wide dynamic range for output power variations. 6 refs., 8 figs

  14. Measurement Results of the Caltech Submillimeter Observatory 230 GHz and 460 GHz Balanced Receivers

    Science.gov (United States)

    Kooi, J. W.; Monje, R. R.; Force, B. L.; Rice, F.; Miller, D.; Phillips, T. G.

    2010-03-01

    The Caltech Submillimeter observatory (CSO) is located on top of Mauna Kea, Hawaii, at an altitude of 4.2km. The existing suite of heterodyne receivers covering the submillimeter band is rapidly aging, and in need of replacement. To this extend we have developed a family of balanced receivers covering the astrophysical important 180-720 GHz atmospheric windows. For the CSO, wide IF bandwidth receivers are implemented in a balanced receiver configuration with dual frequency observation capability. This arrangement was opted to be an optimal compromise between scientific merit and finite funding. In principle, the balanced receiver configuration has the advantage that common mode amplitude noise in the LO system is canceled, while at the same time utilizing all available LO power. Both of these features facilitate the use of commercially available synthesized LO system. In combination with a 4 GHz IF bandwidth, the described receiver layout allows for rapid high resolution spectral line surveys. Dual frequency observation is another important mode of operation offered by the new facility instrumentation. Two band observations are accomplished by separating the H and V polarizations of the incoming signal and routing them via folded optics to the appropriate polarization sensitive balanced mixer. Scientifically this observation mode facilitates pointing for the higher receiver band under mediocre weather conditions and a doubling of scientific throughput (2 x 4 GHz) under good weather conditions. Not only do these changes greatly enhance the spectroscopic capabilities of the CSO, they also enable the observatory to be integrated into the Harvard-Smithsonian Submillimeter Array (eSMA) as an additional baseline. The upgrade of the 345 GHz/650 GHz dual band balanced receivers is not far behind. All the needed hardware has been procured, and commissioning is expected the summer of 2010. The SIS junctions are capable of a 2-12 GHz bandwidth.

  15. Traveling-Wave Maser for 32 GHz

    Science.gov (United States)

    Shell, James; Clauss, Robert

    2009-01-01

    The figure depicts a traveling-wave ruby maser that has been designed (though not yet implemented in hardware) to serve as a low-noise amplifier for reception of weak radio signals in the frequency band of 31.8 to 32.3 GHz. The design offers significant improvements over previous designs of 32-GHz traveling-wave masers. In addition, relative to prior designs of 32-GHz amplifiers based on high-electron-mobility transistors, this design affords higher immunity to radio-frequency interference and lower equivalent input noise temperature. In addition to the basic frequency-band and low-noise requirements, the initial design problem included a requirement for capability of operation in a closed-cycle helium refrigerator at a temperature .4 K and a requirement that the design be mechanically simplified, relative to prior designs, in order to minimize the cost of fabrication and assembly. Previous attempts to build 32- GHz traveling-wave masers involved the use of metallic slow-wave structures comprising coupled transverse electromagnetic (TEM)-mode resonators that were subject to very tight tolerances and, hence, were expensive to fabricate and assemble. Impedance matching for coupling signals into and out of these earlier masers was very difficult. A key feature of the design is a slow-wave structure, the metallic portions of which would be mechanically relatively simple in that, unlike in prior slow-wave structures, there would be no internal metal steps, irises, or posts. The metallic portions of the slow-wave structure would consist only of two rectangular metal waveguide arms. The arms would contain sections filled with the active material (ruby) alternating with evanescent-wave sections. This structure would be transparent in both the signal-frequency band (the aforementioned range of 31.8 to 32.3 GHz) and the pump-frequency band (65.75 to 66.75 GHz), and would impose large slowing factors in both frequency bands. Resonant ferrite isolators would be placed in the

  16. Pulsed high-power beams

    International Nuclear Information System (INIS)

    Reginato, L.L.; Birx, D.L.

    1988-01-01

    The marriage of induction linac technology with nonlinear magnetic modulators has produced some unique capabilities. It is now possible to produce short-pulse electron beams with average currents measured in amperes, at gradients approaching 1-MeV/m, and with power efficiencies exceeding 50%. This paper reports on a 70-MeV, 3-kA induction accelerator (ETA II) constructed at the Lawrence Livermore National Laboratory that incorporates the pulse technology concepts that have evolved over the past several years. The ETA II is a linear induction accelerator and provides a test facility for demonstration of the high-average-power components and high-brightness sources used in such accelerators. The pulse drive of the accelerator is based on state-of-the-art magnetic pulse compressors with very high peak-power capability, repetition rates exceeding 1 kHz, and excellent reliability

  17. Some experimental and theoretical aspects of the surface impedance in bulk high-temperature superconductors at 10 GHz

    Energy Technology Data Exchange (ETDEWEB)

    Deville, A.; Fawaz, H.; Gaillard, B. (Lab. d' Electronique des Milieux Condenses, Univ. de Provence, Centre Saint-Jerome, 13 - Marseille (France)); Noel, H.; Potel, M. (Lab. de Chimie Minerale, Univ. de Rennes, 35 (France)); Monnereau, O. (Lab. de Chimie des Materiaux, Univ. de Provence, Centre Saint-Charles, 13 - Marseille (France))

    1992-07-15

    After a presentation of the theoretical framework, and a short review of existing r.f. results in high-temperature superconductors, we present our own 10 GHz measurements on YBa[sub 2]Cu[sub 3]O[sub 7] single crystals and sintered samples. We use an electron spin resonance (ESR) heterodyne spectrometer and measurements of the reflection coefficient and resonant frequency of a cavity to get information not only on the surface resistance, R[sub S], as generally done, but also on the surface reactance, X[sub S]. The theoretical analysis of the frequency shift is made by adapting Slater's perturbation method to the present problem. In order to explain both the R[sub s] and X[sub S] results, and previous ESR observations, while keeping theoretical simplicity, we are led to suggest that in the normal state these materials show an unconventional skin effect, where the phenomenon is governed not by the d.c. conductivity, but by an effective (lower) conductivity, the other characteristics being unchanged. We briefly discuss the superconductor results and the validity of the two-fluid model. (orig.).

  18. Resonant excitation of high order modes in the 3.9 GHz cavity of the Linac Coherent Light Source

    Science.gov (United States)

    Lunin, A.; Khabiboulline, T.; Solyak, N.; Sukhanov, A.; Yakovlev, V.

    2018-02-01

    Construction of the Linac Coherent Light Source II (LCLS-II) is underway for the world's first hard x-ray free-electron laser. A central part of the LCLS-II project is a 4 GeV superconducting radio frequency electron linac that will operate in the continuous wave (cw) mode. The linac is segmented into four sections named as L 0 , L 1 , L 2 , and L 3 . Two 3.9 GHz cryomodules, each housing of eight third-harmonic cavities similar to the cavities developed for the European X-ray Free Electron Laser (XFEL), will be used in section L 1 of the linac for linearizing the longitudinal beam profile. In this paper, we present a study of trapped high order modes (HOMs) excited by a cw electron beam in the third-harmonic cavities of the LCLS-II linac. A detailed comparison of the original XFEL design and the LCLS-II design with a modified end group is performed in order to estimate the effect of a reduced beam pipe aperture on the efficiency of HOM damping. Furthermore, we apply a statistical analysis of the eigenmode spectrum for the estimation of the probability of resonant HOM losses and influence of HOMs on beam dynamics.

  19. A highly linear power amplifier for WLAN

    International Nuclear Information System (INIS)

    Jin Jie; Shi Jia; Ai Baoli; Zhang Xuguang

    2016-01-01

    A three-stage power amplifier (PA) for WLAN application in 2.4-2.5 GHz is presented. The proposed PA employs an adaptive bias circuit to adjust the operating point of the PA to improve the linearity of the PA. Two methods to short the 2nd harmonic circuit are compared in the area of efficiency and gain of the PA. The PA is taped out in the process of 2 μm InGaP/GaAs HBT and is tested by the evaluation board. The measured results show that 31.5 dB power gain and 29.3 dBm P 1dB with an associated 40.4% power added efficiency (PAE) under the single tone stimulus. Up to 26.5 dBm output power can be achieved with an error vector magnitude (EVM) of lower than 3% under the 64QAM/OFDM WLAN stimulus. (paper)

  20. The high-resolution structure of the Centaurus A nucleus at 2.3 and 8.4 GHz

    International Nuclear Information System (INIS)

    Meier, D.L.; Preston, R.A.; Morabito, D.D.

    1989-01-01

    VLBI observations of the nucleus of Centaurus A have been made at two frequencies with an array of five Australian radio telescopes as part of the Southern Hemisphere VLBI Experiment. Observations were made at 2.3 GHz with all five antennas, while only two were employed at 8.4 GHz. At 2.3 GHz seven tracks in the (u,v) plane with coverage of 6-8 hr each were obtained, yielding significant information on the structure of the nuclear jet. At 8.4 GHz a compact unresolved core was detected as well. It is found that the source consists of the compact self-absorbed core, a jet containing a set of three knots extending from 100 to 160 mas from the core, and a very long, narrow component elongated along the same position angle as the knots. The allowable range for the position angle of the jet is 51 + or - 3 deg, in agreement with that of the radio and X-ray structure on arcsecond and arcminute scales. The jet has brightened at 2.3 GHz by about 4 Jy, a factor of nearly 3, since the early 1970s, 1.8 Jy of which has occurred in the last 2 yr with no discernable changes in structure. 21 refs

  1. High power laser exciter accelerators

    International Nuclear Information System (INIS)

    Martin, T.H.

    1975-01-01

    Recent developments in untriggered oil and water switching now permit the construction of compact, high energy density pulsed power sources for laser excitation. These accelerators, developed principally for electron beam fusion studies, appear adaptable to laser excitation and will provide electron beams of 10 13 to 10 14 W in the next several years. The accelerators proposed for e-beam fusion essentially concentrate the available power from the outside edge of a disk into the central region where the electron beam is formed. One of the main problem areas, that of power flow at the vacuum diode insulator, is greatly alleviated by the multiplicity of electron beams that are allowable for laser excitation. A proposal is made whereby the disk-shaped pulsed power sections are stacked vertically to form a series of radially flowing electron beams to excite the laser gas volume. (auth)

  2. High power fast ramping power supplies

    Energy Technology Data Exchange (ETDEWEB)

    Marneris,I.; Bajon, E.; Bonati, R.; Sandberg, J.; Roser, T.; Tsoupas, N.

    2009-05-04

    Hundred megawatt level fast ramping power converters to drive proton and heavy ion machines are under research and development at accelerator facilities in the world. This is a leading edge technology. There are several topologies to achieve this power level. Their advantages and related issues will be discussed.

  3. Development of High Power Amplifiers for Space and Ground-based Applications

    DEFF Research Database (Denmark)

    Hernández, Carlos Cilla

    The power amplifier used in the transmitter of a microwave system is a key issue, and it derermines the system performance, cost, power consumption and reliability to a considerable extent. Traditionally, most of high power amplifiers used in military and commercial applications were tube......, the device was delivering power levels larger than 75 W, PAE >35% and gain oscillating between 7.5 +/- 0.5 dB. Measurements were shifted down in frequency 1 GHz, but simulations predicted maximum power levels similar to the ones measured....

  4. 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.

  5. High-power, high-efficiency FELs

    International Nuclear Information System (INIS)

    Sessler, A.M.

    1989-04-01

    High power, high efficiency FELs require tapering, as the particles loose energy, so as to maintain resonance between the electromagnetic wave and the particles. They also require focusing of the particles (usually done with curved pole faces) and focusing of the electromagnetic wave (i.e. optical guiding). In addition, one must avoid transverse beam instabilities (primarily resistive wall) and longitudinal instabilities (i.e sidebands). 18 refs., 7 figs., 3 tabs

  6. High voltage power network construction

    CERN Document Server

    Harker, Keith

    2018-01-01

    This book examines the key requirements, considerations, complexities and constraints relevant to the task of high voltage power network construction, from design, finance, contracts and project management to installation and commissioning, with the aim of providing an overview of the holistic end to end construction task in a single volume.

  7. Heating power at the substrate, electron temperature, and electron density in 2.45 GHz low-pressure microwave plasma

    Science.gov (United States)

    Kais, A.; Lo, J.; Thérèse, L.; Guillot, Ph.

    2018-01-01

    To control the temperature during a plasma treatment, an understanding of the link between the plasma parameters and the fundamental process responsible for the heating is required. In this work, the power supplied by the plasma onto the surface of a glass substrate is measured using the calorimetric method. It has been shown that the powers deposited by ions and electrons, and their recombination at the surface are the main contributions to the heating power. Each contribution is estimated according to the theory commonly used in the literature. Using the corona balance, the Modified Boltzmann Plot (MBP) is employed to determine the electron temperature. A correlation between the power deposited by the plasma and the results of the MBP has been established. This correlation has been used to estimate the electron number density independent of the Langmuir probe in considered conditions.

  8. High Temperature, High Power Piezoelectric Composite Transducers

    Science.gov (United States)

    Lee, Hyeong Jae; Zhang, Shujun; Bar-Cohen, Yoseph; Sherrit, StewarT.

    2014-01-01

    Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined. PMID:25111242

  9. Design of Jet lower hybrid current drive generator and operation of high power test bed

    International Nuclear Information System (INIS)

    Dobbing, J.A.; Bosia, G.; Brandon, M.; Gammelin, M.; Gormezano, C.; Jacquinot, J.; Jessop, G.; Lennholm, M.; Pain, M.; Sibley, A.

    1989-01-01

    The JET Lower Hybrid Current Drive (LHCD) generator consists of 24 klystrons each rated for 650 KW operating at 3.7 GHz, giving a nominal generator power of 15.6 MW for 10 seconds or 12 MW for 20 seconds. This power will be transmitted through 24 waveguides to a phased array launcher on one of the main ports of the JET machine. In addition, two klystrons are currently being operated on a high power test bed to establish reliable operation of the generators components and test high power microwave components prior to their installation

  10. High Power Electron Accelerator Prototype

    CERN Document Server

    Tkachenko, Vadim; Cheskidov, Vladimir; Korobeynikov, G I; Kuznetsov, Gennady I; Lukin, A N; Makarov, Ivan; Ostreiko, Gennady; Panfilov, Alexander; Sidorov, Alexey; Tarnetsky, Vladimir V; Tiunov, Michael A

    2005-01-01

    In recent time the new powerful industrial electron accelerators appear on market. It caused the increased interest to radiation technologies using high energy X-rays due to their high penetration ability. However, because of low efficiency of X-ray conversion for electrons with energy below 5 MeV, the intensity of X-rays required for some industrial applications can be achieved only when the beam power exceeds 300 kW. The report describes a project of industrial electron accelerator ILU-12 for electron energy up to 5 MeV and beam power up to 300 kW specially designed for use in industrial applications. On the first stage of work we plan to use the existing generator designed for ILU-8 accelerator. It is realized on the GI-50A triode and provides the pulse power up to 1.5-2 MW and up to 20-30 kW of average power. In the report the basic concepts and a condition of the project for today are reflected.

  11. Production of intense beams of highly charged heavy ions from RIKEN 18 GHz ECRIS and liquid He free SC-ECRIS

    International Nuclear Information System (INIS)

    Nakagawa, T.; Kidera, M.; Kageyama, T.; Kase, M.; Yano, Y.; Higurashi, Y.; Kurita, T.; Imanaka, M.

    2001-01-01

    We have constructed the high performance ECRISs for RIKEN RI Beam factory project and successfully produced intense beams of highly charged heavy ions. RIKEN 18 GHz ECRIS can especially produce intense beams of medium charge states of heavy ions (1.3 mA of Ar 8+ , 200 eμA of Xe 20+ ) by applying the various techniques, e.g., Al cylinder method, biased electrode method, optimization of the plasma electrode position. Very recently, we successfully produced intense beams of highly charged heavy ions (10 eμA of Xe 30+ , 1 eμA of Xe 36+ ) from the Liquid He free SC-ECRIS with operational frequency of 14 GHz

  12. The Atacama Cosmology Telescope: A Measurement of the 600 less than l less than 8000 Cosmic Microwave Background Power Spectrum at 148 GHz

    Science.gov (United States)

    Fowler, J. W.; Acquaviva, V.; Ade, P. A. R.; Aguirre, P.; Amiri, M.; Appel, J. W.; Barrientos, L. F.; Bassistelli, E. S.; Bond, J. R.; Brown, B.; hide

    2010-01-01

    We present a measurement of the angular power spectrum of the cosmic microwave background (CMB) radiation observed at 148 GHz. The measurement uses maps with 1.4' angular resolution made with data from the Atacama Cosmology Telescope (ACT). The observations cover 228 deg(sup 2) of the southern sky, in a 4 deg. 2-wide strip centered on declination 53 deg. South. The CMB at arc minute angular scales is particularly sensitive to the Silk damping scale, to the Sunyaev-Zel'dovich (SZ) effect from galaxy dusters, and to emission by radio sources and dusty galaxies. After masking the 108 brightest point sources in our maps, we estimate the power spectrum between 600 less than l less than 8000 using the adaptive multi-taper method to minimize spectral leakage and maximize use of the full data set. Our absolute calibration is based on observations of Uranus. To verify the calibration and test the fidelity of our map at large angular scales, we cross-correlate the ACT map to the WMAP map and recover the WMAP power spectrum from 250 less than l less than 1150. The power beyond the Silk damping tail of the CMB (l approximately 5000) is consistent with models of the emission from point sources. We quantify the contribution of SZ clusters to the power spectrum by fitting to a model normalized to sigma 8 = 0.8. We constrain the model's amplitude A(sub sz) less than 1.63 (95% CL). If interpreted as a measurement of as, this implies sigma (sup SZ) (sub 8) less than 0.86 (95% CL) given our SZ model. A fit of ACT and WMAP five-year data jointly to a 6-parameter ACDM model plus point sources and the SZ effect is consistent with these results.

  13. 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.

  14. High-power microwave transmission and launching systems for fusion plasma heating systems

    International Nuclear Information System (INIS)

    Bigelow, T.S.

    1989-01-01

    Microwave power in the 30- to 300-GHz frequency range is becoming widely used for heating of plasma in present-day fusion energy magnetic confinement experiments. Microwave power is effective in ionizing plasma and heating electrons through the electron cyclotron heating (ECH) process. Since the power is absorbed in regions of the magnetic field where resonance occurs and launching antennas with narrow beam widths are possible, power deposition location can be highly controlled. This is important for maximizing the power utilization efficiency and improving plasma parameters. Development of the gyrotron oscillator tube has advanced in recent years so that a 1-MW continuous-wave, 140-GHz power source will soon be available. Gyrotron output power is typically in a circular waveguide propagating a circular electric mode (such as TE 0,2 ) or a whispering-gallery mode (such as TE 15,2 ), depending on frequency and power level. An alternative high-power microwave source currently under development is the free-electron laser (FEL), which may be capable of generating 2-10 MW of average power at frequencies of up to 500 GHz. The FEL has a rectangular output waveguide carrying the TE 0,1 mode. Because of its higher complexity and cost, the high-average-power FEL is not yet as extensively developed as the gyrotron. In this paper, several types of operating ECH transmission systems are discussed, as well systems currently being developed. The trend in this area is toward higher power and frequency due to the improvements in plasma density and temperature possible. Every system requires a variety of components, such as mode converters, waveguide bends, launchers, and directional couplers. Some of these components are discussed here, along with ongoing work to improve their performance. 8 refs

  15. Compact and Ultra-Low-Power 2.4 GHz LNA for On-body Communication Devices

    DEFF Research Database (Denmark)

    Ruaro, Andrea; Gülstorff, Steen; Jakobsen, Kaj Bjarne

    2015-01-01

    components. The noise figure is as low as 1.5 dB with an associated power gain of 6.2 dB while it consumes less than 1 mW drawn from a 1 V supply. The input third-order intercept point (IIP3) and the 1-dB compression point (P1dB) are −11 and −9 dBm, respectively. The input and output return loss are better...

  16. Low conversion loss 94 GHz and 188 GHz doublers in InP DHBT technology

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Johansen, Tom Keinicke; Squartecchia, Michele

    2017-01-01

    An Indium Phosphide (InP) Double Heterojunction Bipolar Transistor (DHBT) process has been utilized to design two doublers to cover the 94 GHz and 188 GHz bands. The 94 GHz doubler employs 4-finger DHBTs and provides conversion loss of 2 dB. A maximum output power of nearly 3 dBm is measured whil...... operate over a broad bandwidth. The total circuit area of each chip is 1.41 mm2....

  17. A high-efficiency low-voltage class-E PA for IoT applications in sub-1 GHz frequency range

    Science.gov (United States)

    Zhou, Chenyi; Lu, Zhenghao; Gu, Jiangmin; Yu, Xiaopeng

    2017-10-01

    We present and propose a complete and iterative integrated-circuit and electro-magnetic (EM) co-design methodology and procedure for a low-voltage sub-1 GHz class-E PA. The presented class-E PA consists of the on-chip power transistor, the on-chip gate driving circuits, the off-chip tunable LC load network and the off-chip LC ladder low pass filter. The design methodology includes an explicit design equation based circuit components values' analysis and numerical derivation, output power targeted transistor size and low pass filter design, and power efficiency oriented design optimization. The proposed design procedure includes the power efficiency oriented LC network tuning, the detailed circuit/EM co-simulation plan on integrated circuit level, package level and PCB level to ensure an accurate simulation to measurement match and first pass design success. The proposed PA is targeted to achieve more than 15 dBm output power delivery and 40% power efficiency at 433 MHz frequency band with 1.5 V low voltage supply. The LC load network is designed to be off-chip for the purpose of easy tuning and optimization. The same circuit can be extended to all sub-1 GHz applications with the same tuning and optimization on the load network at different frequencies. The amplifier is implemented in 0.13 μm CMOS technology with a core area occupation of 400 μm by 300 μm. Measurement results showed that it provided power delivery of 16.42 dBm at antenna with efficiency of 40.6%. A harmonics suppression of 44 dBc is achieved, making it suitable for massive deployment of IoT devices. Project supported by the National Natural Science Foundation of China (No. 61574125) and the Industry Innovation Project of Suzhou City of China (No. SYG201641).

  18. Status of the high current permanent magnet 2.45 GHz ECR ion source at Peking University

    International Nuclear Information System (INIS)

    Peng, S.X.; Song, Z.Z.; Yu, J.X.; Ren, H.T.; Zhang, M.; Yuan, Z.X.; Lu, P.N.; Zhao, J.; Chen, J.E.; Guo, Z.Y.; Lu, Y.R.

    2012-01-01

    Several compact 2.45 GHz Electron Cyclotron Resonance Ion Sources (ECRIS) have been developed at Peking University for ion implantation, for the Separated Function Radio Frequency Quadrupole project (SFRFQ) and for the Peking University Neutron Imaging Facility project (PKUNIFTY). Studies on 2.45 GHz ECR ion sources are concentrated on methods of microwave coupling and microwave window design, magnetic field generation and configuration, as well as the extraction electrodes structure. Investigation also covers the influence of the size of plasma chamber on the discharge efficiency and species factor. Up to now, our sources have produced 25 mA of O + ions, 40 mA of He + ions, 10 mA of N + ions, 100 mA of H + ions and 83 mA of D + ions, respectively. The paper is followed by the slides of the presentation. (authors)

  19. State-of-the-art of high power gyro-devices and free electron masers 1994

    International Nuclear Information System (INIS)

    Thumm, M.

    1995-04-01

    At present, gyrotron oscillators are mainly used as high power millimeter wave sources for electron cyclotron resonance heating (ECRH) and diagnostics of magnetically confined plasmas for generation of energy by controlled thermonuclear fusion. 140 GHz gyrotrons with output power P out =0.54 MW, pulse length τ=3.0 s and efficiency η=42% are commercially available. Total efficiencies around 50% have been achieved using single-stage depressed collectors. Diagnostic gyrotrons deliver P out =40 kW with τ=40 μs at frequencies up to 650 GHz (η≥4%). Recently, gyrotron oscillators have also been successfully used in material processing and plasma chemistry. Such technological applications require gyrotrons with the following parameters: f≥24 GHz, P out =10-50 kW, CW, η≥30%. This paper reports on achievements and problems related to the development of very high power mm-wave gyrotrons for long pulse or CW operation and describes the microwave technological pecularities of the different development steps. In addition, this work gives a short overview of the present development of gyrotrons for technological applications, relativistic gyrotrons, quasi-optical gyrotrons, cyclotron autoresonance masers (CARMs), gyro klystrons, gyro-TWT amplifiers, gyrotwystron amplifiers, gyro-BWO's, peniotrons and free electron masers (FEMs). The most impressive FEM output parameters are: P out =2 GW, τ=20 ns, η=13% at 140 GHz (LLNL) and P out =15 kW, τ=20 μs, η=5% in the range from 120 to 900 GHz (UCSB). (orig.) [de

  20. Diamond Windows for High Powered Microwave Transmission. Final Report

    International Nuclear Information System (INIS)

    Gat, R.

    2011-01-01

    This phase II SBIR developed technology for manufacturing diamond windows for use in high energy density photon transmission e.g. microwave or laser light photons. Microwave sources used in fusion research require microwave extraction windows with high thermal conductivity, low microwave absorption, and low resistance to thermal cracking. Newly developed, man made diamond windows have all three of these properties, but these windows are prohibitively expensive. This limits the natural progress of these important technologies to higher powers and slows the development of additional applications. This project developed a lower cost process for manufacturing diamond windows using microwave plasma. Diamond windows were deposited. A grinding process was used to provide optical smoothness for 2 cm diameter diamond windows that met the parallelism specifications for fusion beam windows. The microwave transmission performance (loss tangent) of one of the windows was measured at 95GHz to be less than 10-4, meeting specifications for utilization in the ITER tokamak.

  1. Class 1 bluetooth power amplifier with 24dBm output power and 48% PAE at 2.4GHz in 0.25um CMOS

    NARCIS (Netherlands)

    Vathulay, V.; Sowlati, T.; Leenaerts, D.M.W.

    2001-01-01

    In this paper, we report an RF power amplifier design in digital CMOS technology for the Class 1 power level specification (20 dBm) in the Bluetooth Communications standard. We have also investigated hot carrier effects under large signal RF operation of the power amplifier. The two stage circuit,

  2. An Automatic Control System for Conditioning 30 GHz Accelerating Structures

    CERN Document Server

    Dubrovskiy, A

    2008-01-01

    A software application programme has been developed to allow fast and automatic high-gradient conditioning of accelerating structures at 30 GHz in CTF3. The specificity of the application is the ability to control the high-power electron beam which produces the 30 GHz RF power used to condition the accelerating structures. The programme permits operation round the clock with minimum manpower requirements. In this paper the fast control system, machine control system, logging system, graphical user control interface and logging data visualization are described. An outline of the conditioning control system itself and of the feedback controlling peak power and pulse length is given. The software allows different types of conditioning strategies to be programmed

  3. A 10kWatt 36GHz Solid-State Power Amplifier using GaN-on-Diamond, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase-I SBIR proposal proposes for the first time ever, the use of a new class of materials - Gallium Nitride-on-diamond - in the manufacture of very high...

  4. A 90 GHz photoinjector

    International Nuclear Information System (INIS)

    Palmer, D.T.; Hogan, M.J.; Ferrario, M.; Serafini, L.

    1999-01-01

    Photocathode rf guns depend on mode locked laser systems to produce an electron beam at a given phase of the rf. In general, the laser pulse is less than σ 2 = 10'' of rf phase in length and the required stability is on the order of Δφ = 1 At 90 GHz (W-band), these requirements correspond to σ 2 = 333 fsec and Δφ = 33 fsec. Laser system with pulse lengths in the fsec regime are commercially available, the timing stability is a major concern. It is proposed a multi-cell W-band photoinjector that does not require a mode locked laser system. Thereby eliminating the stability requirements at W-band. The laser pulse is allowed to be many rf periods long. In principle, the photoinjector can now be considered as a thermionic rf gun. Instead of using an alpha magnet to compress the electron bunch, which would have a detrimental effect on the transverse hase space quality due to longitudinal phase space mixing, it is here proposed to use long pulse laser system and a pair of undulators to produce a low emittance, high current, ultra-short electron bunch for beam dynamics experiments in the 90 GHz regime

  5. High average power solid state laser power conditioning system

    International Nuclear Information System (INIS)

    Steinkraus, R.F.

    1987-01-01

    The power conditioning system for the High Average Power Laser program at Lawrence Livermore National Laboratory (LLNL) is described. The system has been operational for two years. It is high voltage, high power, fault protected, and solid state. The power conditioning system drives flashlamps that pump solid state lasers. Flashlamps are driven by silicon control rectifier (SCR) switched, resonant charged, (LC) discharge pulse forming networks (PFNs). The system uses fiber optics for control and diagnostics. Energy and thermal diagnostics are monitored by computers

  6. Environmental assessment for the Satellite Power System (SPS): studies of honey bees exposed to 2. 45 GHz continuous-wave electromagnetic energy

    Energy Technology Data Exchange (ETDEWEB)

    Gary, N E; Westerdahl, B B

    1980-12-01

    A system for small animal exposure was developed for treating honey bees, Apis mellifera L., in brood and adult stages, with 2.45 GHz continuous wave microwaves at selected power densities and exposure times. Post-treatment brood development was normal and teratological effects were not detected at exposures of 3 to 50 mw/cm/sup 2/ for 30 minutes. Post-treatment survival, longevity, orientation, navigation, and memory of adult bees were also normal after exposures of 3 to 50 mw/cm/sup 2/ for 30 minutes. Post-treatment longevity of confined bees in the laboratory was normal after exposures of 3 to 50 mw/cm/sup 2/ for 24 hours. Thermoregulation of brood nest, foraging activity, brood rearing, and social interaction were not affected by chronic exposure to 1 mw/cm/sup 2/ during 28 days. In dynamic behavioral bioassays the frequency of entry and duration of activity of unrestrained, foraging adult bees was identical in microwave-exposed (5 to 40 mw/cm/sup 2/) areas versus control areas.

  7. High power microwave source development

    Science.gov (United States)

    Benford, James N.; Miller, Gabriel; Potter, Seth; Ashby, Steve; Smith, Richard R.

    1995-05-01

    The requirements of this project have been to: (1) improve and expand the sources available in the facility for testing purposes and (2) perform specific tasks under direction of the Defense Nuclear Agency about the applications of high power microwaves (HPM). In this project the HPM application was power beaming. The requirements of this program were met in the following way: (1) We demonstrated that a compact linear induction accelerator can drive HPM sources at repetition rates in excess of 100 HZ at peak microwave powers of a GW. This was done for the relativistic magnetron. Since the conclusion of this contract such specifications have also been demonstrated for the relativistic klystron under Ballistic Missile Defense Organization funding. (2) We demonstrated an L band relativistic magnetron. This device has been used both on our single pulse machines, CAMEL and CAMEL X, and the repetitive system CLIA. (3) We demonstrated that phase locking of sources together in large numbers is a feasible technology and showed the generation of multigigawatt S-band radiation in an array of relativistic magnetrons.

  8. High-power pulsed lasers

    International Nuclear Information System (INIS)

    Holzrichter, J.F.

    1980-01-01

    The ideas that led to the successful construction and operation of large multibeam fusion lasers at the Lawrence Livermore Laboratory are reviewed. These lasers are based on the use of Nd:glass laser materials. However, most of the concepts are applicable to any laser being designed for fusion experimentation. This report is a summary of lectures given by the author at the 20th Scottish University Summer School in Physics, on Laser Plasma Interaction. This report includes basic concepts of the laser plasma system, a discussion of lasers that are useful for short-pulse, high-power operation, laser design constraints, optical diagnostics, and system organization

  9. 100 GHz, 1 MW, CW gyrotron study program. Final report

    International Nuclear Information System (INIS)

    Felch, K.; Bier, R.; Caplan, M.; Jory, H.

    1983-09-01

    The results of a study program to investigate the feasibility of various approaches in designing a 100 GHz, 1 MW CW gyrotron are presented. A summary is given of the possible configurations for a high average power, high frequency gyrotron, including an historical survey of experimental results which are relevant to the various approaches. A set of basic scaling considerations which enable qualitative comparisons between particular gyrotron interaction circuits is presented. These calculations are important in understanding the role of various electron beam and circuit parameters in achieving a viable gyrotron design. Following these scaling exercises, a series of design calculations is presented for a possible approach in achieving 100 GHz, 1 MW CW. These calculations include analyses of the electron gun and interaction circuit parts of the gyrotron, and a general analysis of other aspects of a high average power, high frequency gyrotron. Scalability of important aspects of the design to other frequencies is also discussed, as well as key technology issues

  10. A 60 GHz Frequency Generator Based on a 20 GHz Oscillator and an Implicit Multiplier

    NARCIS (Netherlands)

    Zong, Z.; Babaie, M.; Staszewski, R.B.

    2016-01-01

    This paper proposes a mm-wave frequency generation technique that improves its phase noise (PN) performance and power efficiency. The main idea is that a fundamental 20 GHz signal and its sufficiently strong third harmonic at 60 GHz are generated simultaneously in a single oscillator. The desired 60

  11. Metallic plates lens focalizing a high power microwave beam

    International Nuclear Information System (INIS)

    Rebuffi, L.

    1987-08-01

    A metallic grating composed of thin parallel plates opportunely spaced, permits to correct the phase of an incident high power microwave beam. In this work we show how it is possible to obtain a beam focalisation (lens), a beam deflection (prisma), or a variation in the polarization (polarizer) using parallel metallic plates. The main design parameters are here presented, in order to obtain the wanted phase modification keeping low the diffraction, the reflected power, the ohmic losses and avoiding breakdowns. Following the given criteria, a metallic plate lens has been realized to focalize the 200 KW, 100 msec 60 GHz beam used in the ECRH experiment on the TFR tokamak. The experimental beam concentration followed satisfactory the design requirements. In fact, the maximum intensity increased about twice the value without lens. In correspondence of this distance a reduction of the beam size of about 50% have been measured for the -3 dB radius. The lens supported high power tests without breakdowns or increase of the reflected power

  12. Commissioning of the superconducting ECR ion source VENUS at 18 GHz

    International Nuclear Information System (INIS)

    Leitner, Daniela; Abbott, Steven R.; Dwinell, Roger D.; Leitner, Matthaeus; Taylor, Clyde E.; Lyneis, Claude M.

    2004-01-01

    During the last year, the VENUS ECR ion source was commissioned at 18 GHz and preparations for 28 GHz operation are now underway. During the commissioning phase with 18 GHz, tests with various gases and metals have been performed with up to 2000 W RF power. The ion source performance is very promising [1,2]. VENUS (Versatile ECR ion source for Nuclear Science) is a next generation superconducting ECR ion source, designed to produce high current, high charge state ions for the 88-Inch Cyclotron at the Lawrence Berkeley National Laboratory. VENUS also serves as the prototype ion source for the RIA (Rare Isotope Accelerator) front end. The goal of the VENUS ECR ion source project as the RIA R and D injector is the production of 240e(micro)A of U 30+ , a high current medium charge state beam. On the other hand, as an injector ion source for the 88-Inch Cyclotron the design objective is the production of 5e(micro)A of U 48+ , a low current, very high charge state beam. To meet these ambitious goals, VENUS has been designed for optimum operation at 28 GHz. This frequency choice has several design consequences. To achieve the required magnetic confinement, superconducting magnets have to be used. The size of the superconducting magnet structure implies a relatively large plasma volume. Consequently, high power microwave coupling becomes necessary to achieve sufficient plasma heating power densities. The 28 GHz power supply has been delivered in April 2004

  13. 6‐GHz‐to‐18‐GHz AlGaN/GaN Cascaded Nonuniform Distributed Power Amplifier MMIC Using Load Modulation of Increased Series Gate Capacitance

    Directory of Open Access Journals (Sweden)

    Dong‐Hwan Shin

    2017-10-01

    Full Text Available A 6‐GHz‐to‐18‐GHz monolithic nonuniform distributed power amplifier has been designed using the load modulation of increased series gate capacitance. This amplifier was implemented using a 0.25‐μm AlGaN/GaN HEMT process on a SiC substrate. With the proposed load modulation, we enhanced the amplifier's simulated performance by 4.8 dB in output power, and by 13.1% in power‐added efficiency (PAE at the upper limit of the bandwidth, compared with an amplifier with uniform gate coupling capacitors. Under the pulse‐mode condition of a 100‐μs pulse period and a 10% duty cycle, the fabricated power amplifier showed a saturated output power of 39.5 dBm (9 W to 40.4 dBm (11 W with an associated PAE of 17% to 22%, and input/output return losses of more than 10 dB within 6 GHz to 18 GHz.

  14. Investigation of a metallic photonic crystal high power microwave mode converter

    Directory of Open Access Journals (Sweden)

    Dong Wang

    2015-02-01

    Full Text Available It is demonstrated that an L band metallic photonic crystal TEM-TE11 mode converter is suitable for narrow band high power microwave application. The proposed mode converter is realized by partially filling metallic photonic crystals along azimuthal direction in a coaxial transmission line for phase-shifting. A three rows structure is designed and simulated by commercial software CST Microwave Studio. Simulation results show that its conversion efficiency is 99% at the center frequency 1.58 GHz. Over the frequency range of 1.56-1.625 GHz, the conversion efficiency exceeds 90 %, with a corresponding bandwidth of 4.1 %. This mode converter has a gigawatt level power handling capability which is suitable for narrow band high power microwave application. Using magnetically insulated transmission line oscillator(MILO as a high power microwave source, particle-in-cell simulation is carried out to test the performance of the mode converter. The expected TE11 mode microwave output is obtained and the MILO works well. Mode conversion performance of the converter is tested by far-field measurement method. And the experimental result confirms the validity of our design. Then, high power microwave experiment is carried out on a Marx-driven Blumlein water line pulsed power accelerator. Microwave frequency, radiated pattern and power are measured in the far-field region and the results agree well with simulation results. The experiment also reveals that no microwave breakdown or pulse shortening took place in the experimental setup.

  15. HIGH-RESOLUTION OBSERVATIONS OF DUST CONTINUUM EMISSION AT 340 GHz FROM THE LOW-MASS T TAURI STAR FN TAURI

    International Nuclear Information System (INIS)

    Momose, Munetake; Ohashi, Nagayoshi; Kudo, Tomoyuki; Tamura, Motohide; Kitamura, Yoshimi

    2010-01-01

    FN Tau is a rare example of a very low-mass T Tauri star that exhibits a spatially resolved nebulosity in near-infrared scattering light. To directly derive the parameters of a circumstellar disk around FN Tau, observations of dust continuum emission at 340 GHz are carried out with the Submillimeter Array (SMA). A point-like dust continuum emission was detected with a synthesized beam of ∼0.''7 in FWHM. From the analysis of the visibility plot, the radius of the emission is estimated to be ≤0.''29, corresponding to 41 AU. This is much smaller than the radius of the nebulosity, 1.''85 for its brighter part at 1.6 μm. The 340 GHz continuum emission observed with the SMA and the photometric data at λ ≤ 70 μm are explained by a power-law disk model whose outer radius and mass are 41 AU and (0.24-5.9) x 10 -3 M sun , respectively, if the exponent of dust mass opacity (β) is assumed to be 0-2. The disk model cannot fully reproduce the flux density at 230 GHz obtained with the IRAM 30 m telescope, suggesting that there is another extended 'halo' component that is missed in the SMA observations. By requiring the halo not to be detected with the SMA, the lower limit to the size of the halo is evaluated to be between 174 AU and 574 AU, depending on the assumed β value. This size is comparable to the near-infrared nebulosity, implying that the halo unseen with the SMA corresponds to the origin of the near-infrared nebulosity. The halo can contain mass comparable to or at most 8 times greater than that of the inner power-law disk, but its surface density should be lower than that at the outer edge of the power-law disk by more than 1 order of magnitude. The physical nature of the halo is unclear, but it may be the periphery of a flared circumstellar disk that is not described well in terms of a power-law disk model, or a remnant of a protostellar envelope having flattened structure.

  16. A highly linear power amplifier for WLAN

    Science.gov (United States)

    Jie, Jin; Jia, Shi; Baoli, Ai; Xuguang, Zhang

    2016-02-01

    A three-stage power amplifier (PA) for WLAN application in 2.4-2.5 GHz is presented. The proposed PA employs an adaptive bias circuit to adjust the operating point of the PA to improve the linearity of the PA. Two methods to short the 2nd harmonic circuit are compared in the area of efficiency and gain of the PA. The PA is taped out in the process of 2 μm InGaP/GaAs HBT and is tested by the evaluation board. The measured results show that 31.5 dB power gain and 29.3 dBm P1dB with an associated 40.4% power added efficiency (PAE) under the single tone stimulus. Up to 26.5 dBm output power can be achieved with an error vector magnitude (EVM) of lower than 3% under the 64QAM/OFDM WLAN stimulus. Project supported by the National Natural Science Foundation of China (No. 61201244) and the Natural Science Fund of SUES (No. E1-0501-14-0168).

  17. A high-average power tapered FEL amplifier at submillimeter frequencies using sheet electron beams and short-period wigglers

    International Nuclear Information System (INIS)

    Bidwell, S.W.; Radack, D.J.; Antonsen, T.M. Jr.; Booske, J.H.; Carmel, Y.; Destler, W.W.; Granatstein, V.L.; Levush, B.; Latham, P.E.; Zhang, Z.X.

    1990-01-01

    A high-average-power FEL amplifier operating at submillimeter frequencies is under development at the University of Maryland. Program goals are to produce a CW, ∼1 MW, FEL amplifier source at frequencies between 280 GHz and 560 GHz. To this end, a high-gain, high-efficiency, tapered FEL amplifier using a sheet electron beam and a short-period (superconducting) wiggler has been chosen. Development of this amplifier is progressing in three stages: (1) beam propagation through a long length (∼1 m) of short period (λ ω = 1 cm) wiggler, (2) demonstration of a proof-of-principle amplifier experiment at 98 GHz, and (3) designs of a superconducting tapered FEL amplifier meeting the ultimate design goal specifications. 17 refs., 1 fig., 1 tab

  18. High peak power tubes and gate effect Klystrons

    International Nuclear Information System (INIS)

    Gerbelot, N.; Bres, M.; Faillon, G.; Buzzi, J.M.

    1993-01-01

    The conventional microwave tubes such as TWTs, Magnetrons, Klystrons... deliver the very high peak powers which are required by radar transmitters but more especially by many particle accelerators. In the range of a few hundred MHz to about 10 GHz, some dozen of MWs per unit are currently obtained and commercially available, according to the frequency and the pulse lengths. But peak power requirements are ever increasing, especially for the expected new linear particle acceleratores, where several hundred MWs per tube would be necessary. Also some special military transmitters begin to request GW pulses, with short pulse lengths - of course - but at nonnegligible repetition rates. Therefore several laboratories and microwave vacuum tube manufacturers have engaged - for several years - studies and development in the field of very high peak microwave power (HPM) toward two main directions: extended operation and extrapolation of the conventional tubes and devices; development of new concepts, among which the most promising are likely the high-current relativistic klystrons - that are also referred to as gate effect klystrons

  19. Results of RIKEN superconducting electron cyclotron resonance ion source with 28 GHz.

    Science.gov (United States)

    Higurashi, Y; Ohnishi, J; Nakagawa, T; Haba, H; Tamura, M; Aihara, T; Fujimaki, M; Komiyama, M; Uchiyama, A; Kamigaito, O

    2012-02-01

    We measured the beam intensity of highly charged heavy ions and x-ray heat load for RIKEN superconducting electron cyclotron resonance ion source with 28 GHz microwaves under the various conditions. The beam intensity of Xe(20+) became maximum at B(min) ∼ 0.65 T, which was ∼65% of the magnetic field strength of electron cyclotron resonance (B(ECR)) for 28 GHz microwaves. We observed that the heat load of x-ray increased with decreasing gas pressure and field gradient at resonance zone. It seems that the beam intensity of highly charged heavy ions with 28 GHz is higher than that with 18 GHz at same RF power.

  20. Optics assembly for high power laser tools

    Science.gov (United States)

    Fraze, Jason D.; Faircloth, Brian O.; Zediker, Mark S.

    2016-06-07

    There is provided a high power laser rotational optical assembly for use with, or in high power laser tools for performing high power laser operations. In particular, the optical assembly finds applications in performing high power laser operations on, and in, remote and difficult to access locations. The optical assembly has rotational seals and bearing configurations to avoid contamination of the laser beam path and optics.

  1. Design of a 300 GHz Broadband TWT Coupler and RF-Structure

    CERN Document Server

    Krawczyk, F L

    2004-01-01

    Recent LANL activities in millimeter wave structures focus on 94 and 300 GHz structures. They aim at power generation from low power (100–2000 W) with a round electron beam (120 kV, 0.1–1.0 A) to high power (2–100 kW) with a sheet beam structure (120 kV, 20 A). Applications cover basic research, radar and secure communications and remote sensing of biological and chemical agents. In this presentation the design and cold-test measurements of a 300 GHz RF-structure with a broadband (>6% bandwidth) power coupler are presented. The design choice of two input/output waveguides, a special coupling region and the structure parameters themselves are presented. As a benchmark also a scaled up version at 10 GHz was designed and measured. These results will also be presented.

  2. High-power, high-frequency, annular-beam free-electron maser

    International Nuclear Information System (INIS)

    Fazio, M.V.; Carlsten, B.E.; Earley, L.M.; Fortgang, C.M.; Haynes, W.B.; Haddock, P.C.

    1998-01-01

    The authors have developed a 15--17 GHz free electron maser (FEM) capable of producing high power pulses with a phase stability appropriate for linear collider applications. The electron beam source is a 1 micros, 800 kV, 5 kA, 6-cm-dia annular electron beam machine called BANSHEE. The beam interacts with the TM 02 mode Raman FEM amplifier in a corrugated cylindrical waveguide where the beam runs close to the interaction device walls to reduce the power density in the fields. They studied the phase stability by analyzing the dispersion relation for an axial FEL, in which the rf field was transversely wiggled and the electron trajectories were purely longitudinal. Detailed particle-in-cell simulations demonstrated the transverse wiggling of the rf mode and the axial FEL interaction and explicit calculations of the growing root of the dispersion relation are included to verify the phase stability

  3. Multi-gigabit wireless data transfer at 60 GHz

    International Nuclear Information System (INIS)

    Soltveit, H K; Schöning, A; Wiedner, D; Brenner, R

    2012-01-01

    In this paper we describe the status of the first prototype of the 60 GHz wireless Multi-gigabit data transfer topology currently under development at University of Heidelberg using IBM 130 nm SiGe HBT BiCMOS technology. The 60 GHz band is very suitable for high data rate and short distance applications. One application can be a wireless multi Gbps radial data transmission inside the ATLAS silicon strip detector, making a first level track trigger feasible. The wireless transceiver consists of a transmitter and a receiver. The transmitter includes an On-Off Keying (OOK) modulator, a Local Oscillator (LO), a Power Amplifier (PA) and a Band-pass Filter (BPF). The receiver part is composed of a Band-pass Filter (BPF), a Low Noise Amplifier (LNA), a double balanced down-convert Gilbert mixer, a Local Oscillator (LO), then a BPF to remove the mixer introduced noise, an Intermediate Amplifier (IF), an On-Off Keying demodulator and a limiting amplifier. The first prototype would be able to handle a data-rate of about 3.5 Gbps over a link distance of 1 m. The first simulations of the LNA show that a Noise figure (NF) of 5 dB, a power gain of 21 dB at 60 GHz with a 3 dB bandwidth of more than 20 GHz with a power consumption 11 mW are achieved. Simulations of the PA show an output referred compression point P1dB of 19.7 dB at 60 GHz.

  4. high power facto high power factor high power factor hybrid rectifier

    African Journals Online (AJOL)

    eobe

    increase in the number of electrical loads that some kind of ... components in the AC power system. Thus, suppl ... al output power; assuring reliability in ... distribution systems. This can be ...... Thesis- Califonia Institute of Technology, Capitulo.

  5. Experimental study of a 1 MW, 170 GHz gyrotron oscillator

    Science.gov (United States)

    Kimura, Takuji

    A detailed experimental study is presented of a 1 MW, 170 GHz gyrotron oscillator whose design is consistent with the ECH requirements of the International Thermonuclear Experimental Reactor (ITER) for bulk heating and current drive. This work is the first to demonstrate that megawatt power level at 170 GHz can be achieved in a gyrotron with high efficiency for plasma heating applications. Maximum output power of 1.5 MW is obtained at 170.1 GHz in 85 kV, 50A operation for an efficiency of 35%. Although the experiment at MIT is conducted with short pulses (3 μs), the gyrotron is designed to be suitable for development by industry for continuous wave operation. The peak ohmic loss on the cavity wall for 1 MW of output power is calculated to be 2.3 kW/cm2, which can be handled using present cooling technology. Mode competition problems in a highly over-moded cavity are studied to maximize the efficiency. Various aspects of electron gun design are examined to obtain high quality electron beams with very low velocity spread. A triode magnetron injection gun is designed using the EGUN simulation code. A total perpendicular velocity spread of less than 8% is realized by designing a low- sensitivity, non-adiabatic gun. The RF power is generated in a short tapered cavity with an iris step. The operating mode is the TE28,8,1 mode. A mode converter is designed to convert the RF output to a Gaussian beam. Power and efficiency are measured in the design TE28,8,1 mode at 170.1 GHz as well as the TE27,8,1 mode at 166.6 GHz and TE29,8,1 mode at 173.5 GHz. Efficiencies between 34%-36% are consistently obtained over a wide range of operating parameters. These efficiencies agree with the highest values predicted by the multimode simulations. The startup scenario is investigated and observed to agree with the linear theory. The measured beam velocity ratio is consistent with EGUN simulation. Interception of reflected beam by the mod-anode is measured as a function of velocity ratio

  6. Development of frequency step tunable 1 MW gyrotron at 131 to 146.5 GHz

    Energy Technology Data Exchange (ETDEWEB)

    Samartsev, A.; Gantenbein, G.; Dammertz, G.; Illy, S.; Kern, S.; Leonhardt, W.; Schlaich, A.; Schmid, M.; Thumm, M., E-mail: andrey.samartsev@kit.edu [Karlsruhe Institute of Technology, Association EURATOM-KIT, Karlsruhe (Germany)

    2011-07-01

    Effective control of power absorption in tokamaks and stellarators could be achieved by the frequency tuning of ECH and CD power delivered by high-power gyrotrons. In this report some results of the development of a frequency tunable gyrotron with fused-silica Brewster window are presented. Excitation of several modes at 1 MW power level in the range of frequencies from 131 to 146.5 GHz is achieved. (author)

  7. High power ubitron-klystron

    International Nuclear Information System (INIS)

    Balkcum, A.J.; McDermott, D.B.; Luhmann, N.C. Jr.

    1997-01-01

    A coaxial ubitron is being considered as the rf driver for the Next Linear Collider (NLC). Prior simulation of a traveling-wave ubitron using a self-consistent code found that 200 MW of power and 53 dB of gain could be achieved with 37% efficiency. In a ubiron-klystron, a series of cavities are used to obtain an even tighter electron bunch for higher efficiency. A small-signal theory of the ubitron-klystron shows that gain scales with the square of the cavity separation distance. A linear stability theory has also been developed. Verification of the stability theory has been achieved using the 2-12-D PIC code, MAGIC, and the particle-tracing code. Saturation characteristics of the amplifier will be presented using both MAGIC and a simpler self-consistent slow-timescale code currently under development. The ubitron can also operate as a compact, highly efficient oscillator. Cavities only two wiggler periods in length have yielded up to 40% rf conversion efficiency in simulation. An initial oscillator design for directed energy applications will also be presented

  8. Simplified High-Power Inverter

    Science.gov (United States)

    Edwards, D. B.; Rippel, W. E.

    1984-01-01

    Solid-state inverter simplified by use of single gate-turnoff device (GTO) to commutate multiple silicon controlled rectifiers (SCR's). By eliminating conventional commutation circuitry, GTO reduces cost, size and weight. GTO commutation applicable to inverters of greater than 1-kilowatt capacity. Applications include emergency power, load leveling, drives for traction and stationary polyphase motors, and photovoltaic-power conditioning.

  9. NASA developments in solid state power amplifiers

    Science.gov (United States)

    Leonard, Regis F.

    1990-01-01

    Over the last ten years, NASA has undertaken an extensive program aimed at development of solid state power amplifiers for space applications. Historically, the program may be divided into three phases. The first efforts were carried out in support of the advanced communications technology satellite (ACTS) program, which is developing an experimental version of a Ka-band commercial communications system. These first amplifiers attempted to use hybrid technology. The second phase was still targeted at ACTS frequencies, but concentrated on monolithic implementations, while the current, third phase, is a monolithic effort that focusses on frequencies appropriate for other NASA programs and stresses amplifier efficiency. The topics covered include: (1) 20 GHz hybrid amplifiers; (2) 20 GHz monolithic MESFET power amplifiers; (3) Texas Instruments' (TI) 20 GHz variable power amplifier; (4) TI 20 GHz high power amplifier; (5) high efficiency monolithic power amplifiers; (6) GHz high efficiency variable power amplifier; (7) TI 32 GHz monolithic power amplifier performance; (8) design goals for Hughes' 32 GHz variable power amplifier; and (9) performance goals for Hughes' pseudomorphic 60 GHz power amplifier.

  10. Review of Power System Stability with High Wind Power Penetration

    DEFF Research Database (Denmark)

    Hu, Rui; Hu, Weihao; Chen, Zhe

    2015-01-01

    analyzing methods and stability improvement approaches. With increasing wind power penetration, system balancing and the reduced inertia may cause a big threaten for stable operation of power systems. To mitigate or eliminate the wind impacts for high wind penetration systems, although the practical......This paper presents an overview of researches on power system stability with high wind power penetration including analyzing methods and improvement approaches. Power system stability issues can be classified diversely according to different considerations. Each classified issue has special...... and reliable choices currently are the strong outside connections or sufficient reserve capacity constructions, many novel theories and approaches are invented to investigate the stability issues, looking forward to an extra-high penetration or totally renewable resource based power systems. These analyzing...

  11. Design of a 300 GHZ broadband coupler and RF-structure

    International Nuclear Information System (INIS)

    Krawczyk, F.L.; Carlsten, B.E.; Earley, L.M.; Sigler, F.E.; Potter, J.M.; Schulze, M.E.

    2004-01-01

    Recent LANL activities in millimeter wave structures focus on 95 and 300 GHz structures. They aim at power generation from low power (100W-2kW) with a round electron beam (120kV, 0.1-1.0 A) to high power (2-100 kW) with a sheet beam structure (120 kV, 20 A). Applications cover basic research, radar and secure communications and remote sensing of biological and chemical agents. In this presentation the design of a 300 GHz RF-structure with a broadband (> 6% bandwidth) power coupler is presented. The choice of two input/output waveguides, a special coupling region and the structure parameters are presented. As a benchmark also a scaled up version at 10 GHz was designed and measured. These results will also be presented. We are investigating planar micro-fabricated traveling-wave tube amplifiers as sources for the generation of millimeter waves from 95 to 300 GHz. While for low energy applications narrow structures with pencil beams are proposed, for high energy operation flat, thin sheet beams are required. For the latter vane-loaded rectangular waveguides that operate in a slow-wave mode matched to the velocity of the electron beam are especially well suited. The 300 GHz effort initially is limited to narrow structures for pencil beams. The main emphasis for this work are the study of fabrication issues and the understanding of features that allow a broadband operation (5-10% bandwidth).

  12. Operation and control of high power Gyrotrons for ECRH systems in SST-1 and Aditya

    Energy Technology Data Exchange (ETDEWEB)

    Shukla, B.K., E-mail: shukla@ipr.res.in; Bora, D.; Jha, R.; Patel, Jatin; Patel, Harshida; Babu, Rajan; Dhorajiya, Pragnesh; Dalakoti, Shefali; Purohit, Dharmesh

    2016-11-15

    Highlights: • Operation and control of high power Gyrotrons. • Data acquisition and control (DAQ) for Gyrotron system. • Ignitron based crowbar protection. • VME and PXI based systems. - Abstract: The Electron Cyclotron Resonance Heating (ECRH) system is an important heating system for the reliable start-up of tokamak. The 42 GHz and 82.6 GHz ECRH systems are used in tokamaks SST-1 and Aditya to carry out ECRH related experiments. The Gyrotrons are high power microwave tubes used as a source for ECRH systems. The Gyrotron is a delicate microwave tube, which deliver megawatt level power at very high voltage ∼40–50 kV with the current requirement ∼10 A–50 A. The Gyrotrons are associated with the subsystems like: High voltage power supplies (Beam voltage and anode voltage), dedicated crowbar system, magnet, filament and ion pump power supplies, cooling, interlocks and a dedicated data acquisition & control (DAC) system. There are two levels of interlocks used for the protection of Gyrotron: fast interlocks (arcing, beam over current, dI/dt, anode voltage and anode over current etc.) operate within 10 μs and slow interlocks (cooling, filament, silence of Gyrotron, ion pump and magnet currents) operate within 100 ms. Two Gyrotrons (42 GHz/500 kW/500 ms and 82.6 GHz/200 kW/1000 s) have been commissioned on dummy load for full parameters. The 42 GHz ECRH system has been integrated with SST-1 & Aditya tokamak and various experiments have been carried out related to ECRH assisted breakdown and start-up of tokamak at fundamental and second harmonic. These Gyrotrons are operated with VME based data acquisition and control (DAC) system. The DAC system is capable to acquire 64 digital and 32 analog signals. The system is used to monitor & acquire the data and also used for slow interlocks for the protection of Gyrotron. The data acquired from the system are stored online on VME system and after the shot stored in a file in binary format. The MDSPlus, a set of

  13. Electronic DC transformer with high power density

    NARCIS (Netherlands)

    Pavlovský, M.

    2006-01-01

    This thesis is concerned with the possibilities of increasing the power density of high-power dc-dc converters with galvanic isolation. Three cornerstones for reaching high power densities are identified as: size reduction of passive components, reduction of losses particularly in active components

  14. High Power Test of an X-Band Slotted-IRIS Accelerator Structure at NLCTA

    International Nuclear Information System (INIS)

    Doebert, S.; Fandos, R.; Grudiev, A.; Heikkinen, S.; Rodriquez, J.A.; Taborelli, M.; Wuensch, W.; Adolphsen, Chris E.; Laurent, L.

    2007-01-01

    The CLIC study group at CERN has built two X-band HDS (hybrid damped structure) accelerating structures for high-power testing in NLCTA at SLAC. These accelerating structures are novel with respect to their rf- design and their fabrication technique. The eleven-cell constant impedance structures, one made out of copper and one out of molybdenum, are assembled from clamped high-speed milled quadrants. They feature the same heavy higher-order-mode damping as nominal CLIC structures achieved by slotted irises and radial damping waveguides for each cell. The X-band accelerators are exactly scaled versions of structures tested at 30 GHz in the CLIC test facility, CTF3. The results of the X-band tests are presented and compared to those at 30 GHz to determine frequency scaling, and are compared to the extensive copper data from the NLC structure development program to determine material dependence and make a basic validation of the HDS design

  15. High power CW linac in PNC

    International Nuclear Information System (INIS)

    Toyama, S.; Wang, Y.L.; Emoto, T.

    1994-01-01

    Power Reactor and Nuclear Fuel Development Corporation (PNC) is developing a high power electron linac for various applications. The electron beam is accelerated in CW operation to get maximum beam current of 100 mA and energy of 10 MeV. Crucial components such as a high power L-band klystron and a high power traveling wave resonant ring (TWRR) accelerator guides were designed and manufactured and their performance were examined. These design and results from the recent high power RF tests were described in this paper. (author)

  16. A 2 MW, CW, 170 GHz gyrotron for ITER

    International Nuclear Information System (INIS)

    Piosczyk, B.; Arnold, A.; Alberti, S.

    2003-01-01

    A 140 GHz gyrotron for CW operation is under development for the stellarator W7-X. With a prototype tube a microwave output power of about 0.9 MW has been obtained in pulses up to 180 s, limited by the capability of the high voltage power supply. The development work on coaxial cavity gyrotrons has demonstrated the feasibility of manufacturing of a 2 MW, CW 170 GHz tube that could be used for ITER. The problems specific to the coaxial arrangement have been investigated and all relevant information needed for an industrial realization of a coaxial gyrotron have been obtained in short pulse experiments (up to 17 ms). The suitability of critical components for a 2 MW, CW coaxial gyrotron has been studied and a first integrated design has been done. (author)

  17. High Power Density Power Electronic Converters for Large Wind Turbines

    DEFF Research Database (Denmark)

    Senturk, Osman Selcuk

    . For these VSCs, high power density is required due to limited turbine nacelle space. Also, high reliability is required since maintenance cost of these remotely located wind turbines is quite high and these turbines operate under harsh operating conditions. In order to select a high power density and reliability......In large wind turbines (in MW and multi-MW ranges), which are extensively utilized in wind power plants, full-scale medium voltage (MV) multi-level (ML) voltage source converters (VSCs) are being more preferably employed nowadays for interfacing these wind turbines with electricity grids...... VSC solution for wind turbines, first, the VSC topology and the switch technology to be employed should be specified such that the highest possible power density and reliability are to be attained. Then, this qualitative approach should be complemented with the power density and reliability...

  18. Experimental progress on virtual-cathode very high power microwave source development

    International Nuclear Information System (INIS)

    Fazio, M.V.; Hoeberling, R.F.

    1987-01-01

    The evolution of rf accelerator technology toward high-power, high-current, low-emittance beams produces an ever-increasing demand for efficient, very high power microwave sources. The present klystron technology has performed very well but is not expected to produce reliable gigawatt peak-power units in the 1- to 10-GHz regime. Further major advancements must involve other types of sources. The reflexing electron sources can produce microwave powers at the gigawatt level and have demonstrated operation from 800 MHz to 40 GHz. Pulse length appears to be limited by electron-beam diode closure, and reflexing electron devices have been operated in a repetitively pulsed mode. An experiment is under way to investigate concepts to stabilize the frequency of the virtual cathode source. If one can successfully frequency and phase lock this source to an external signal, then this source can operate as a very high power microwave amplifier making it practical for accelerator applications. The progress on an experiment to test these concepts will be discussed

  19. High Power Fiber Laser Test Bed

    Data.gov (United States)

    Federal Laboratory Consortium — This facility, unique within DoD, power-combines numerous cutting-edge fiber-coupled laser diode modules (FCLDM) to integrate pumping of high power rare earth-doped...

  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. State-of-the-art of high power gyro-devices and free electron masers. Update 2015

    Energy Technology Data Exchange (ETDEWEB)

    Thumm, Manfred [Karlsruher Institut fuer Technologie (KIT), Eggenstein-Leopoldshafen (Germany). Inst. fuer Hochleistungsimpuls- und Mikrowellentechnik, Programm Fusion

    2016-07-01

    Gyrotron oscillators (gyromonotrons) are mainly used as high power millimeter wave sources for electron cyclotron resonance heating (ECRH), electron cyclotron current drive (ECCD), stability control and diagnostics of magnetically confined plasmas for generation of energy by controlled thermonuclear fusion. The maximum pulse length of commercially available 140 GHz, megawatt- class gyrotrons employing synthetic diamond output windows is 30 minutes (CPI and European KIT-CRPP-TED collaboration). The world record parameters of the European megawatt-class 140 GHz gyrotron are: 0.92 MW output power at 30 min. pulse duration, 97.5% Gaussian mode purity and 44% efficiency, employing a single-stage depressed collector (SDC) for energy recovery. A maximum output power of 1.5 MW in 4.0 s pulses at 45% efficiency was generated with the JAEA-TOSHIBA 110 GHz gyrotron. The Japan 170 GHz ITER gyrotron achieved 1 MW, 800 s at 55% efficiency and holds the energy world record of 2.88 GJ (0.8 MW, 60 min.) and the efficiency record of 57% for tubes with an output power of more than 0.5 MW. The Russian 170 GHz ITER gyrotron achieved 0.99 (1.2) MW with a pulse duration of 1000 (100) s and 53 (53) % efficiency. The prototype tube of the European 2 MW, 170 GHz coaxial-cavity gyrotron achieved in short pulses the record power of 2.1 MW at 46% efficiency and 96% Gaussian mode purity. Gyrotrons with pulsed magnet for various short-pulse applications deliver P{sub out}=210 kW with τ=20 μs at frequencies up to 670 GHz (η≅20%), P{sub out}=5.3 kW at 1 THz (η=6.1%), and P{sub out}=0.5 kW at 1.3 THz (η=0.6%). Gyrotron oscillators have also been successfully used in materials processing. Such technological applications require gyrotrons with the following parameters: f ≥ 24 GHz, P{sub out}=4-50 kW, CW, η≥30%. This paper gives an update of the experimental achievements related to the development of high power gyrotron oscillators for long-pulse or CW operation and pulsed gyrotrons for

  2. CARM and harmonic gyro-amplifier experiments at 17 GHz

    International Nuclear Information System (INIS)

    Menninger, W.L.; Danly, B.G.; Alberti, S.; Chen, C.; Rullier, J.L.; Temkin, R.J.

    1993-01-01

    Cyclotron resonance maser amplifiers are possible sources for applications such as electron cyclotron resonance heating of fusion plasmas and driving high-gradient rf linear accelerators. For accelerator drivers, amplifiers or phase locked-oscillators are required. A 17 GHz cyclotron autoresonance maser (CARM) amplifier experiment and a 17 GHz third harmonic gyro-amplifier experiment are presently underway at the MIT Plasma Fusion Center. Using the SRL/MIT SNOMAD II introduction accelerator to provide a 380 kV, 180 A, 30 ns flat top electron beam, the gyro-amplifier experiment has produced 5 MW of rf power with over 50 dB of gain at 17 GHz. The gyro-amplifier operates in the TE 31 mode using a third harmonic interaction. Because of its high power output, the gyro-amplifier will be used as the rf source for a photocathode rf electron gun experiment also taking place at MIT. Preliminary gyro-amplifier results are presented, including measurement of rf power, gain versus interaction length, and the far-field pattern. A CARM experiment designed to operate in the TE 11 mode is also discussed

  3. The Design of a High Speed Low Power Phase Locked Loop

    CERN Document Server

    Liu, Tiankuan; Hou, Suen; Liang, Zhihua; Liu, Chonghan; Su, Da-Shung; Teng, Ping-Kun; Xiang, Annie C; Ye, Jingbo

    2009-01-01

    The upgrade of the ATLAS Liquid Argon Calorimeter readout system calls for the development of radiation tolerant, high speed and low power serializer ASIC. We have designed a phase locked loop using a commercial 0.25-μm Silicon-on- Sapphire (SoS) CMOS technology. Post-layout simulation indicates that tuning range is 3.79 – 5.01 GHz and power consumption is 104 mW. The PLL has been submitted for fabrication. The design and simulation results are presented.

  4. High Power Wireless Transfer : For Charging High Power Batteries

    OpenAIRE

    Gill, Himmat

    2017-01-01

    Wireless power transfer (WPT) is developing with emerging of new technologies that has made it possible to transfer electricity over certain distances without any physical contact, offering significant benefits to modern automation systems, medical applications, consumer electronic, and especially in electric vehicle systems. The goal of this study is to provide a brief review of existing compensation topologies for the loosely coupled transformer. The technique used to simulate a co...

  5. High Power laser power conditioning system new discharge circuit research

    CERN Document Server

    Li Yi; Peng Han Sheng; Zhou Pei Zhang; Zheng Wan Guo; Guo Lang Fu; Chen Li Hua; Chen De Hui; Lai Gui You; Luan Yong Ping

    2002-01-01

    The new discharge circuit of power conditioning system for high power laser is studied. The theoretical model of the main discharge circuit is established. The pre-ionization circuit is studied in experiment. In addition, the explosion energy of the new large xenon lamp is successfully measured. The conclusion has been applied to 4 x 2 amplifier system

  6. Superconducting high frequency high power resonators

    International Nuclear Information System (INIS)

    Hobbis, C.; Vardiman, R.; Weinman, L.

    1974-01-01

    A niobium superconducting quarter-wave helical resonator has been designed and built. The resonator has been electron-beam welded and electropolished to produce a smooth flaw-free surface. This has been followed by an anodization to produce a 1000 A layer of Nb 2 0 5 . At the resonant frequency of approximately 15 MHz the unloaded Q was approximately equal to 4.6x10 6 with minimal dielectric support. With the resonator open to the helium bath to provide cooling, and rigidly supported by a teflon cylinder, 350 V of power were transferred at a doubly loaded Q of 3500. The extrapolation of the results to a Qsub(DL) of 1000 meet the power handling criteria of one kilowatt for the intended application. (author)

  7. A Wideband High-Gain Dual-Polarized Slot Array Patch Antenna for WiMAX Applications in 5.8 GHz

    Directory of Open Access Journals (Sweden)

    Amir Reza Dastkhosh

    2012-01-01

    Full Text Available A low-cost, easy-to-fabricate, wideband and high-gain dual-polarized array antenna employing an innovative microstrip slot patch antenna element is designed and fabricated. The design parameters of the antenna are optimized using commercial softwares (Microwave Office and Zeland IE3D to get the suitable -parameters and radiation patterns. Finally, the simulation results are compared to the experimental ones and a good agreement is demonstrated. The antenna has an approximately bandwidth of 14% (5.15–5.9 GHz which covers Worldwide Interoperability Microwave Access (WiMAX/5.8. It also has the peak gain of 26 dBi for both polarizations and high isolation between two ports over a wide bandwidth.

  8. Effects of Variable Spot Size on Human Exposure to 95 GHz Millimeter Wave Energy

    Science.gov (United States)

    2017-05-11

    Laboratory. Ross, J. A., Allen, S. J., Beason, C. W., & Johnson, L. R. (2008). Power density measurement of 94-GHz radiofrequency radiation using carbon...effectiveness) at the smallest spot size. 15. SUBJECT TERMS Avoidance, behavior, millimeter waves, nonlethal weapons, radiofrequency 16...System power density measurements (mean ± standard deviation) for the three different power density settings (low, middle, high) used in Experiment 1B

  9. A 31 GHz Survey of Low-Frequency Selected Radio Sources

    Science.gov (United States)

    Mason, B. S.; Weintraub, L.; Sievers, J.; Bond, J. R.; Myers, S. T.; Pearson, T. J.; Readhead, A. C. S.; Shepherd, M. C.

    2009-10-01

    The 100 m Robert C. Byrd Green Bank Telescope and the 40 m Owens Valley Radio Observatory telescope have been used to conduct a 31 GHz survey of 3165 known extragalactic radio sources over 143 deg2 of the sky. Target sources were selected from the NRAO VLA Sky Survey in fields observed by the Cosmic Background Imager (CBI); most are extragalactic active galactic nuclei (AGNs) with 1.4 GHz flux densities of 3-10 mJy. The resulting 31 GHz catalogs are presented in full online. Using a maximum-likelihood analysis to obtain an unbiased estimate of the distribution of the 1.4-31 GHz spectral indices of these sources, we find a mean 31-1.4 GHz flux ratio of 0.110 ± 0.003 corresponding to a spectral index of α = -0.71 ± 0.01 (S ν vprop να) 9.0% ± 0.8% of sources have α > - 0.5 and 1.2% ± 0.2% have α > 0. By combining this spectral-index distribution with 1.4 GHz source counts, we predict 31 GHz source counts in the range 1 mJy S 31) = (16.7 ± 1.7) deg-2(S 31/1 mJy)-0.80±0.07. We also assess the contribution of mJy-level (S 1.4 GHz < 3.4 mJy) radio sources to the 31 GHz cosmic microwave background power spectrum, finding a mean power of ell(ell + 1)C src ell/(2π) = 44 ± 14 μK2 and a 95% upper limit of 80 μK2 at ell = 2500. Including an estimated contribution of 12 μK2 from the population of sources responsible for the turn-up in counts below S 1.4 GHz = 1 mJy, this amounts to 21% ± 7% of what is needed to explain the CBI high-ell excess signal, 275 ± 63 μK2. These results are consistent with other measurements of the 31 GHz point-source foreground.

  10. A broadband high-efficiency Doherty power amplifier using symmetrical devices

    Science.gov (United States)

    Cheng, Zhiqun; Zhang, Ming; Li, Jiangzhou; Liu, Guohua

    2018-04-01

    This paper proposes a method for broadband and high-efficiency amplification of Doherty power amplifier (DPA) using symmetric devices. In order to achieve the perfect load modulation, the carrier amplifier output circuit total power length is designed to odd multiple of 90°, and the peak amplifier output total power length is designed to even multiple of 180°. The proposed method is demonstrated by designing a broadband high-efficiency DPA using identical 10-W packaged GaN HEMT devices. Measurement results show that over 51% drain efficiency is achieved at 6-dB back-off power, over the frequency band of 1.9–2.4 GHz. Project supported by the National Natural Science Foundation of China (No. 60123456), the Zhejiang Provincial Natural Science Foundation of China (No. LZ16F010001), and the Zhejiang Provincial Public Technology Research Project (No. 2016C31070).

  11. Automated System Tests High-Power MOSFET's

    Science.gov (United States)

    Huston, Steven W.; Wendt, Isabel O.

    1994-01-01

    Computer-controlled system tests metal-oxide/semiconductor field-effect transistors (MOSFET's) at high voltages and currents. Measures seven parameters characterizing performance of MOSFET, with view toward obtaining early indication MOSFET defective. Use of test system prior to installation of power MOSFET in high-power circuit saves time and money.

  12. The three-dimensional particle-in-cell simulation analysis of cavity of high power subterahertz pulsed gyrotron

    International Nuclear Information System (INIS)

    Ito, Koyu; Jiang, Weihua

    2013-01-01

    High power sub-terahertz pulsed gyrotrons for Collective Thomson Scattering (CTS) diagnostics of fusion plasmas are being developed. The typical target parameters are: output power of 100-200 kW, operation frequency of 300 GHz, and pulsed length > 10 us. In order to support experimental development, numerical simulations were carried out by using Particle-In-Cell (PIC) code MAGIC. The oscillation mode of the electromagnetic radiation was selected as TE_1_5_,_2, for which the beam parameters and cavity dimensions were determined accordingly. The simulation results have showed maximum power of 144 kW at oscillation frequency of 292.80 GHz, with oscillation efficiency of 22.15%. (author)

  13. Time-dependent spectrum analysis of high power gyrotrons

    International Nuclear Information System (INIS)

    Schlaich, Andreas

    2015-01-01

    In this work, an investigation of vacuum electronic oscillators capable of generating multi-megawatt continuous wave output power in the millimeter-wave range (so-called gyrotrons) through spectral measurements is presented. The centerpiece is the development of a measurement system with a high dynamic range (50-60 dB) for time-dependent spectrum analysis, covering the frequency range 100-170 GHz with instantaneous bandwidths of 6-12 GHz. Despite relying on heterodyne reception through harmonic mixers, the Pulse Spectrum Analysis (PSA) system maintains RF unambiguity in the spectrogram output through the application of a novel RF reconstruction technique. Using the new possibilities, a wide range of spectral phenomena in gyrotrons has been investigated, such as cavity mode jumps, lowfrequency modulation, frequency tuning in long pulses and the spectral behavior during the presence of an RF window arc. A dedicated investigation on parasitic RF oscillations in W7-X gyrotrons combining several analysis techniques led to the conclusion that after-cavity oscillations can be physical reality in high power gyrotrons, and are the probable cause for the undesired signals observed. Apart from systematic parameter sweeps using the PSA system, an analytical dispersion analysis in the Brillouin diagram was applied, and numerical gyrotron interaction simulations of unprecedented extent were conducted. Furthermore, the improved frequency measurement capabilities were employed to analyze the frequency tuning through thermal expansion and electrostatic neutralization caused by ionization inside the tube in long-pulse operation. By macroscopically modeling the gas dynamics and ionization processes in combination with a fitting process, the time dependences of the two processes could be investigated. In doing so, indication was found that the neutralization in W7-X gyrotrons amounts to only 60% of the electrostatic depression voltage, instead of 100% as widely believed for

  14. Time-dependent spectrum analysis of high power gyrotrons

    Energy Technology Data Exchange (ETDEWEB)

    Schlaich, Andreas

    2015-07-01

    In this work, an investigation of vacuum electronic oscillators capable of generating multi-megawatt continuous wave output power in the millimeter-wave range (so-called gyrotrons) through spectral measurements is presented. The centerpiece is the development of a measurement system with a high dynamic range (50-60 dB) for time-dependent spectrum analysis, covering the frequency range 100-170 GHz with instantaneous bandwidths of 6-12 GHz. Despite relying on heterodyne reception through harmonic mixers, the Pulse Spectrum Analysis (PSA) system maintains RF unambiguity in the spectrogram output through the application of a novel RF reconstruction technique. Using the new possibilities, a wide range of spectral phenomena in gyrotrons has been investigated, such as cavity mode jumps, lowfrequency modulation, frequency tuning in long pulses and the spectral behavior during the presence of an RF window arc. A dedicated investigation on parasitic RF oscillations in W7-X gyrotrons combining several analysis techniques led to the conclusion that after-cavity oscillations can be physical reality in high power gyrotrons, and are the probable cause for the undesired signals observed. Apart from systematic parameter sweeps using the PSA system, an analytical dispersion analysis in the Brillouin diagram was applied, and numerical gyrotron interaction simulations of unprecedented extent were conducted. Furthermore, the improved frequency measurement capabilities were employed to analyze the frequency tuning through thermal expansion and electrostatic neutralization caused by ionization inside the tube in long-pulse operation. By macroscopically modeling the gas dynamics and ionization processes in combination with a fitting process, the time dependences of the two processes could be investigated. In doing so, indication was found that the neutralization in W7-X gyrotrons amounts to only 60% of the electrostatic depression voltage, instead of 100% as widely believed for

  15. Powering the High-Luminosity Triplets

    Science.gov (United States)

    Ballarino, A.; Burnet, J. P.

    The powering of the magnets in the LHC High-Luminosity Triplets requires production and transfer of more than 150 kA of DC current. High precision power converters will be adopted, and novel High Temperature Superconducting (HTS) current leads and MgB2 based transfer lines will provide the electrical link between the power converters and the magnets. This chapter gives an overview of the systems conceived in the framework of the LHC High-Luminosity upgrade for feeding the superconducting magnet circuits. The focus is on requirements, challenges and novel developments.

  16. High current and high power superconducting rectifiers

    International Nuclear Information System (INIS)

    Kate, H.H.J. ten; Bunk, P.B.; Klundert, L.J.M. van de; Britton, R.B.

    1981-01-01

    Results on three experimental superconducting rectifiers are reported. Two of them are 1 kA low frequency flux pumps, one thermally and magnetically switched. The third is a low-current high-frequency magnetically switched rectifier which can use the mains directly. (author)

  17. Ferroelectric switch for a high-power Ka-band active pulse compressor

    Energy Technology Data Exchange (ETDEWEB)

    Hirshfield, Jay L. [Omega-P, Inc., New Haven, CT (United States)

    2013-12-18

    Results are presented for design of a high-power microwave switch for operation at 34.3 GHz, intended for use in an active RF pulse compressor. The active element in the switch is a ring of ferroelectric material, whose dielectric constant can be rapidly changed by application of a high-voltage pulse. As envisioned, two of these switches would be built into a pair of delay lines, as in SLED-II at SLAC, so as to allow 30-MW μs-length Ka-band pulses to be compressed in time by a factor-of-9 and multiplied in amplitude to generate 200 MW peak power pulses. Such high-power pulses could be used for testing and evaluation of high-gradient mm-wave accelerator structures, for example. Evaluation of the switch design was carried out with an X-band (11.43 GHz) prototype, built to incorporate all the features required for the Ka-band version.

  18. High power ultrashort pulse lasers

    International Nuclear Information System (INIS)

    Perry, M.D.

    1994-01-01

    Small scale terawatt and soon even petawatt (1000 terawatt) class laser systems are made possible by application of the chirped-pulse amplification technique to solid-state lasers combined with the availability of broad bandwidth materials. These lasers make possible a new class of high gradient accelerators based on the large electric fields associated with intense laser-plasma interactions or from the intense laser field directly. Here, we concentrate on the laser technology to produce these intense pulses. Application of the smallest of these systems to the production of high brightness electron sources is also introduced

  19. Evolution of Very High Frequency Power Supplies

    DEFF Research Database (Denmark)

    Knott, Arnold; Andersen, Toke Meyer; Kamby, Peter

    2013-01-01

    The ongoing demand for smaller and lighter power supplies is driving the motivation to increase the switching frequencies of power converters. Drastic increases however come along with new challenges, namely the increase of switching losses in all components. The application of power circuits used...... in radio frequency transmission equipment helps to overcome those. However those circuits were not designed to meet the same requirements as power converters. This paper summarizes the contributions in recent years in application of very high frequency (VHF) technologies in power electronics, shows results...... of the recent advances and describes the remaining challenges. The presented results include a self-oscillating gate-drive, air core inductor optimizations, an offline LED driver with a power density of 8.9 W/cm3 and a 120 MHz, 9 W DC powered LED driver with 89 % efficiency as well as a bidirectional VHF...

  20. The NASA CSTI High Capacity Power Project

    International Nuclear Information System (INIS)

    Winter, J.; Dudenhoefer, J.; Juhasz, A.; Schwarze, G.; Patterson, R.; Ferguson, D.; Schmitz, P.; Vandersande, J.

    1992-01-01

    This paper describes the elements of NASA's CSTI High Capacity Power Project which include Systems Analysis, Stirling Power Conversion, Thermoelectric Power Conversion, Thermal Management, Power Management, Systems Diagnostics, Environmental Interactions, and Material/Structural Development. Technology advancement in all elements is required to provide the growth capability, high reliability and 7 to 10 year lifetime demanded for future space nuclear power systems. The overall project will develop and demonstrate the technology base required to provide a wide range of modular power systems compatible with the SP-100 reactor which facilitates operation during lunar and planetary day/night cycles as well as allowing spacecraft operation at any attitude or distance from the sun. Significant accomplishments in all of the project elements will be presented, along with revised goals and project timeliness recently developed

  1. HIGH AVERAGE POWER OPTICAL FEL AMPLIFIERS

    International Nuclear Information System (INIS)

    2005-01-01

    Historically, the first demonstration of the optical FEL was in an amplifier configuration at Stanford University [l]. There were other notable instances of amplifying a seed laser, such as the LLNL PALADIN amplifier [2] and the BNL ATF High-Gain Harmonic Generation FEL [3]. However, for the most part FELs are operated as oscillators or self amplified spontaneous emission devices. Yet, in wavelength regimes where a conventional laser seed can be used, the FEL can be used as an amplifier. One promising application is for very high average power generation, for instance FEL's with average power of 100 kW or more. The high electron beam power, high brightness and high efficiency that can be achieved with photoinjectors and superconducting Energy Recovery Linacs (ERL) combine well with the high-gain FEL amplifier to produce unprecedented average power FELs. This combination has a number of advantages. In particular, we show that for a given FEL power, an FEL amplifier can introduce lower energy spread in the beam as compared to a traditional oscillator. This properly gives the ERL based FEL amplifier a great wall-plug to optical power efficiency advantage. The optics for an amplifier is simple and compact. In addition to the general features of the high average power FEL amplifier, we will look at a 100 kW class FEL amplifier is being designed to operate on the 0.5 ampere Energy Recovery Linac which is under construction at Brookhaven National Laboratory's Collider-Accelerator Department

  2. Effect of high power microwaves on rats locomotion and cognition

    International Nuclear Information System (INIS)

    Seze, Rene de; Ammari, Mohamed; Sakly, Mohsen; Abdelmelek, Hafedh

    2008-01-01

    Full text: Introduction: High power microwaves (HPM) are suspected to produce some behavioural deficits in rats, however very few studies have been published on this topics. The aim of our experiment was to determine if exposure to HPM could affect behaviour in locomotor (open field) and memory (objects recognition) tasks. Materials and methods: Exposure Six-weeks male rats were exposed to a 13 cm-diameter electromagnetic beam at 10 GHz ; radiation was emitted through 10 seconds trains of 1 ns-pulses at 100 Hz. Power of the source was 350 MW and peak-intensity of the field was 50 GW/m 2 (6100 kV/m) at 5 cm from the conical emitting horn. A single exposure was applied every 5 minutes for 1 h and the behavioural test was performed in the following hour. Time-averaged SAR over that period was estimated at 0.34 W/kg. Peak-power in one pulse was 95 MW/kg and in any second, 9.5 W/kg. Groups: A group of 12 individually exposed animals was compared to a group of 12 sham-exposed animals, set at the same place and in the same ambient conditions as the exposed animals, but omitting HPM emission. Behaviour: An open-field video-track was performed during the different phases. Each phase includes 3 successive trials of 5 min, with 3 minutes in between. Phase 1 studied spontaneous locomotor activity and animal anxiety by recording its position in the arena (periphery meaning anxiety). Phase 2 looked at exploratory behaviour, adding three objects in the field. Time spent close to the objects reflects curiosity. Phase 3 looked at habituation and spatial memory, changing an object from one quadrant (Nr.3) to another one (Nr.4). Phase 4 looked at memory and attention, changing one object by a new one in quadrant Nr.3. Measured parameters were, for any central or peripheral area, containing or not a previously present or a new object: time spent in a quadrant, number of crossed quadrants and run distance. Results and discussion: No significant difference was found for the different

  3. ACIGA's high optical power test facility

    International Nuclear Information System (INIS)

    Ju, L; Aoun, M; Barriga, P

    2004-01-01

    Advanced laser interferometer detectors utilizing more than 100 W of laser power and with ∼10 6 W circulating laser power present many technological problems. The Australian Consortium for Interferometric Gravitational Astronomy (ACIGA) is developing a high power research facility in Gingin, north of Perth, Western Australia, which will test techniques for the next generation interferometers. In particular it will test thermal lensing compensation and control strategies for optical cavities in which optical spring effects and parametric instabilities may present major difficulties

  4. Development of high power klystron. 3. Development of klystron No.2

    International Nuclear Information System (INIS)

    Hirano, K.; Wang, Y.L.; Sato, I.

    2000-08-01

    A high power klystron has been developed as the RF source of the high power CW electron linac (10 MeV, 100 mA, 1.249135 GHz). CW power of 1.2 MW and efficiencies over 65% at a beam voltage 85 kV were the design goal. We developed a long pill-box type beryllia window (long pill-box window) withstood the RF power of 1.7 MW (CW) and replaced the standard pill-box window of the prototype klystron with long pill-box window. The high power RF test was carried out with the converted klystron. This klystron has achieved CW RF power of 885 kW and efficiency of 47% at beam voltage of 85 kV. This paper describes key points of the designs to achieve the RF power over 1.2 MW and results of the high power RF test of the second klystron, which has been optimized by simulation codes to improve better efficiency. The second klystron has achieved the maximum efficiency of 56.5% with CW output power of 782 kW at a beam voltage of 80 kV and a cathode current of 20.4 A in present. The third klystron will be manufactured to reflect results of this test. (author)

  5. 77 FR 45558 - 4.9 GHz Band

    Science.gov (United States)

    2012-08-01

    ..., our rules currently require 4.9 GHz licensees to ``cooperate in the selection and use of channels in... directional and thus can be represented as narrow paths on a coordination map; in contrast, they note, the low-power, less- directional, geographically-dispersed links in a 4.9 GHz network must be represented as a...

  6. High average-power induction linacs

    International Nuclear Information System (INIS)

    Prono, D.S.; Barrett, D.; Bowles, E.; Caporaso, G.J.; Chen, Yu-Jiuan; Clark, J.C.; Coffield, F.; Newton, M.A.; Nexsen, W.; Ravenscroft, D.; Turner, W.C.; Watson, J.A.

    1989-01-01

    Induction linear accelerators (LIAs) are inherently capable of accelerating several thousand amperes of ∼ 50-ns duration pulses to > 100 MeV. In this paper the authors report progress and status in the areas of duty factor and stray power management. These technologies are vital if LIAs are to attain high average power operation. 13 figs

  7. High average-power induction linacs

    International Nuclear Information System (INIS)

    Prono, D.S.; Barrett, D.; Bowles, E.

    1989-01-01

    Induction linear accelerators (LIAs) are inherently capable of accelerating several thousand amperes of /approximately/ 50-ns duration pulses to > 100 MeV. In this paper we report progress and status in the areas of duty factor and stray power management. These technologies are vital if LIAs are to attain high average power operation. 13 figs

  8. Driver Circuit For High-Power MOSFET's

    Science.gov (United States)

    Letzer, Kevin A.

    1991-01-01

    Driver circuit generates rapid-voltage-transition pulses needed to switch high-power metal oxide/semiconductor field-effect transistor (MOSFET) modules rapidly between full "on" and full "off". Rapid switching reduces time of overlap between appreciable current through and appreciable voltage across such modules, thereby increasing power efficiency.

  9. ICAN: High power neutral beam generation

    International Nuclear Information System (INIS)

    Moustaizis, S.D.; Lalousis, P.; Perrakis, K.; Auvray, P.; Larour, J.; Ducret, J.E.; Balcou, P.

    2015-01-01

    During the last few years there is an increasing interest on the development of alternative high power new negative ion source for Tokamak applications. The proposed new neutral beam device presents a number of advantages with respect to: the density current, the acceleration voltage, the relative compact dimension of the negative ion source, and the coupling of a high power laser beam for photo-neutralization of the negative ion beam. Here we numerically investigate, using a multi- fluid 1-D code, the acceleration and the extraction of high power ion beam from a Magnetically Insulated Diode (MID). The diode configuration will be coupled to a high power device capable of extracting a current up to a few kA with an accelerating voltage up to MeV. An efficiency of up to 92% of the coupling of the laser beam, is required in order to obtain a high power, up to GW, neutral beam. The new high energy, high average power, high efficiency (up to 30%) ICAN fiber laser is proposed for both the plasma generation and the photo-neutralizer configuration. (authors)

  10. Monotron and azimuthally corrugated: application to the high power microwaves generation; Monotron e cavidades azimutalmente corrugadas: aplicacao a geracao de microondas de alta potencia

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Pedro Jose de

    2003-07-01

    The present document reports the activity of construction and initial operation of 6.7 GHz operation for high power microwave generation, the study on cylindrical resonators with azimuthally corrugated cross section, the determination of electrical conductivity of metallic materials and development of dielectric resonators for telecommunication applications.

  11. Development of a high power millimeter wave free-electron laser amplifier

    International Nuclear Information System (INIS)

    Bidwell, S.W.; Zhang, Z.X.; Antonsen, T.M. Jr.; Destler, W.W.; Granatstein, V.L.; Levush, B.; Rodgers, J.; Freund, H.P.

    1992-01-01

    Progress on the development of a high-average-power millimeter wave free-electron laser amplifier is reported. Successful sheet electron beam propagation has been observed through a 54 cm long wiggler magnet. One hundred percent transport efficiency is reported with a 15 A, 0.1 cm x 2.0 cm, sheet electron beam through B w = 5.1 kG, λ w = 0.96 cm, planar electromagnet wiggler. Preliminary success with a novel, yet simple, method of side focusing using offset poles is reported. Status of development on a 94 GHz, 180 kW, pulsed amplifier is discussed with results from numerical simulation

  12. Electron cyclotron heating/current-drive system using high power tubes for QUEST spherical tokamak

    Science.gov (United States)

    Onchi, Takumi; Idei, H.; Hasegawa, M.; Nagata, T.; Kuroda, K.; Hanada, K.; Kariya, T.; Kubo, S.; Tsujimura, T. I.; Kobayashi, S.; Quest Team

    2017-10-01

    Electron cyclotron heating (ECH) is the primary method to ramp up plasma current non-inductively in QUEST spherical tokamak. A 28 GHz gyrotron is employed for short pulses, where the radio frequency (RF) power is about 300 kW. Current ramp-up efficiency of 0.5 A/W has been obtained with focused beam of the second harmonic X-mode. A quasi-optical polarizer unit has been newly installed to avoid arcing events. For steady-state tokamak operation, 8.56 GHz klystron with power of 200 kW is used as the CW-RF source. The high voltage power supply (54 kV/13 A) for the klystron has been built recently, and initial bench test of the CW-ECH system is starting. The array of insulated-gate bipolar transistor works to quickly cut off the input power for protecting the klystron. This work is supported by JSPS KAKENHI (15H04231), NIFS Collaboration Research program (NIFS13KUTR085, NIFS17KUTR128), and through MEXT funding for young scientists associated with active promotion of national university reforms.

  13. Low Power Design with High-Level Power Estimation and Power-Aware Synthesis

    CERN Document Server

    Ahuja, Sumit; Shukla, Sandeep Kumar

    2012-01-01

    Low-power ASIC/FPGA based designs are important due to the need for extended battery life, reduced form factor, and lower packaging and cooling costs for electronic devices. These products require fast turnaround time because of the increasing demand for handheld electronic devices such as cell-phones, PDAs and high performance machines for data centers. To achieve short time to market, design flows must facilitate a much shortened time-to-product requirement. High-level modeling, architectural exploration and direct synthesis of design from high level description enable this design process. This book presents novel research techniques, algorithms,methodologies and experimental results for high level power estimation and power aware high-level synthesis. Readers will learn to apply such techniques to enable design flows resulting in shorter time to market and successful low power ASIC/FPGA design. Integrates power estimation and reduction for high level synthesis, with low-power, high-level design; Shows spec...

  14. High power density carbonate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Yuh, C.; Johnsen, R.; Doyon, J.; Allen, J. [Energy Research Corp., Danbury, CT (United States)

    1996-12-31

    Carbonate fuel cell is a highly efficient and environmentally clean source of power generation. Many organizations worldwide are actively pursuing the development of the technology. Field demonstration of multi-MW size power plant has been initiated in 1996, a step toward commercialization before the turn of the century, Energy Research Corporation (ERC) is planning to introduce a 2.85MW commercial fuel cell power plant with an efficiency of 58%, which is quite attractive for distributed power generation. However, to further expand competitive edge over alternative systems and to achieve wider market penetration, ERC is exploring advanced carbonate fuel cells having significantly higher power densities. A more compact power plant would also stimulate interest in new markets such as ships and submarines where space limitations exist. The activities focused on reducing cell polarization and internal resistance as well as on advanced thin cell components.

  15. Design and experiment of a cross-shaped mode converter for high-power microwave applications

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Shengren, E-mail: 785751053@qq.com; Yuan, Chengwei; Zhong, Huihuang; Fan, Yuwei [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

    2013-12-15

    A compact mode converter, which is capable of converting a TM{sub 01} mode into a circularly polarized TE{sub 11} mode, was developed and experimentally studied with high-power microwaves. The converter, consisting of two turnstile junctions, is very short along the wave propagation direction, and therefore is suitable for designing compact and axially aligned high-power microwave radiation systems. In this paper, the principle of a converter working at 1.75 GHz is demonstrated, as well as the experimental results. The experimental and simulation results are in good agreement. At the center frequency, the conversion efficiency is more than 95%, the measured axial ratio is about 0.4 dB, and the power-handing capacity is excess of 1.9 GW.

  16. High Voltage Power Transmission for Wind Energy

    Science.gov (United States)

    Kim, Young il

    The high wind speeds and wide available area at sea have recently increased the interests on offshore wind farms in the U.S.A. As offshore wind farms become larger and are placed further from the shore, the power transmission to the onshore grid becomes a key feature. Power transmission of the offshore wind farm, in which good wind conditions and a larger installation area than an onshore site are available, requires the use of submarine cable systems. Therefore, an underground power cable system requires unique design and installation challenges not found in the overhead power cable environment. This paper presents analysis about the benefit and drawbacks of three different transmission solutions: HVAC, LCC/VSC HVDC in the grid connecting offshore wind farms and also analyzed the electrical characteristics of underground cables. In particular, loss of HV (High Voltage) subsea power of the transmission cables was evaluated by the Brakelmann's theory, taking into account the distributions of current and temperature.

  17. Gingin High Optical Power Test Facility

    International Nuclear Information System (INIS)

    Zhao, C; Blair, D G; Barrigo, P

    2006-01-01

    The Australian Consortium for Gravitational Wave Astronomy (ACIGA) in collaboration with LIGO is developing a high optical power research facility at the AIGO site, Gingin, Western Australia. Research at the facility will provide solutions to the problems that advanced gravitational wave detectors will encounter with extremely high optical power. The problems include thermal lensing and parametric instabilities. This article will present the status of the facility and the plan for the future experiments

  18. Inverter design for high frequency power distribution

    Science.gov (United States)

    King, R. J.

    1985-01-01

    A class of simple resonantly commutated inverters are investigated for use in a high power (100 KW - 1000 KW) high frequency (10 KHz - 20 KHz) AC power distribution system. The Mapham inverter is found to provide a unique combination of large thyristor turn-off angle and good utilization factor, much better than an alternate 'current-fed' inverter. The effects of loading the Mapham inverter entirely with rectifier loads are investigated by simulation and with an experimental 3 KW 20 KHz inverter. This inverter is found to be well suited to a power system with heavy rectifier loading.

  19. Digital Predistortion of 75-110GHzW-Band Frequency Multiplier for Fiber Wireless Short Range Access Systems

    DEFF Research Database (Denmark)

    Zhao, Ying; Pang, Xiaodan; Deng, Lei

    2011-01-01

    We present a digital predistortion technique to effectively compensate high nonlinearity of a sextuple multiplier operating at 99.6GHz. An 18.9dB adjacent-channel power ratio (ACPR) improvement is guaranteed and a W-band fiber-wireless system is experimentally investigated.......We present a digital predistortion technique to effectively compensate high nonlinearity of a sextuple multiplier operating at 99.6GHz. An 18.9dB adjacent-channel power ratio (ACPR) improvement is guaranteed and a W-band fiber-wireless system is experimentally investigated....

  20. Construction of a High Temporal-spectral Resolution Spectrometer for Detection of Fast Transients from Observations of the Sun at 1.4 GHz.

    Science.gov (United States)

    Casillas-Perez, G. A.; Jeyakumar, S.; Perez-Enriquez, R.

    2014-12-01

    Transients explosive events with time durations from nanoseconds to several hours, are observed in the Sun at high energy bands such as gamma ray and xray. In the radio band, several types of radio bursts are commonly detected from the ground. A few observations of the Sun in the past have also detected a new class of fast transients which are known to have short-live electromagnetic emissions with durations less than 100 ms. The mechanisms that produce such fast transiets remain unclear. Observations of such fast transients over a wide bandwidth is necessary to uderstand the underlying physical process that produce such fast transients. Due to their very large flux densities, fast radio transients can be observed at high time resolution using small antennas in combination with digital signal processing techniques. In this work we report the progress of an spectrometer that is currently in construction at the Observatorio de la Luz of the Universidad de Guanajuato. The instrument which will have the purpose of detecting solar fast radio transients, involves the use of digital devices such as FPGA and ADC cards, in addition with a receiver with high temporal-spectral resolution centered at 1.4 GHz and a pair of 2.3 m satellite dish.

  1. KEY COMPARISON: Final report on CCEM key comparison CCEM.RF-K10.CL (GT-RF/99-2) 'Power in 50 Ω coaxial lines, frequency: 50 MHz to 26 GHz' measurement techniques and results

    Science.gov (United States)

    Janik, Dieter; Inoue, T.; Michaud, A.

    2006-01-01

    This report summarizes the results and the measuring methods of an international key comparison between twelve national metrology institutes (NMIs) and is concerning the calibration factor of RF power sensors in the coaxial 3.5 mm line for frequencies up to 26 GHz. Two RF power travelling standards fitted with male PC 3.5 mm connectors were measured at seven frequencies. The following NMIs participated: NMIJ (Japan), NRC (Canada), NIST (USA), METAS (Switzerland), CSIR-NML (South Africa), NMIA (Australia), NPL (UK), SiQ (Slovenia), IEN (Italy), VNIIFTRI (Russian Federation), SPRING (Singapore) and PTB (Germany), as the pilot laboratory. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  2. 60 GHz wireless data transfer for tracker readout systems—first studies and results

    International Nuclear Information System (INIS)

    Dittmeier, S.; Berger, N.; Schöning, A.; Soltveit, H.K.; Wiedner, D.

    2014-01-01

    To allow highly granular trackers to contribute to first level trigger decisions or event filtering, a fast readout system with very high bandwidth is required. Space, power and material constraints, however, pose severe limitations on the maximum available bandwidth of electrical or optical data transfers. A new approach for the implementation of a fast readout system is the application of a wireless data transfer at a carrier frequency of 60 GHz. The available bandwidth of several GHz allows for data rates of multiple Gbps per link. 60 GHz transceiver chips can be produced with a small form factor and a high integration level. A prototype transceiver currently under development at the University of Heidelberg is briefly described in this paper. To allow easy and fast future testing of the chip's functionality, a bit error rate test has been developed with a commercially available transceiver. Crosstalk might be a big issue for a wireless readout system with many links in a tracking detector. Direct crosstalk can be avoided by using directive antennas, linearly polarized waves and frequency channeling. Reflections from tracking modules can be reduced by applying an absorbing material like graphite foam. Properties of different materials typically used in tracking detectors and graphite foam in the 60 GHz frequency range are presented. For data transmission tests, links using commercially available 60 GHz transmitters and receivers are used. Studies regarding crosstalk and the applicability of graphite foam, Kapton horn antennas and polarized waves are shown

  3. Effect of electrode for producing the highly charged heavy ions from RIKEN 18 GHz electron cyclotron resonance ion source

    International Nuclear Information System (INIS)

    Kurita, Tetsuro; Nakagawa, Takahide; Kidera, Masanori

    1999-01-01

    We successfully produced the intense beam of highly charged Kr ions using an electrode. Under the pulsed mode operation, we found that the depth of the plasma potential dip strongly depends on the duration of the microwave and takes about 40 ms to reach the equilibrium state. Taking these results into account, we compared the beam intensities of highly charged Kr ions with and without the use of an electrode under the pulsed mode operation. We observed that the density of highly charged Kr ions and ion confinement time increase with increasing mirror magnetic field strength. The plasma potential dip becomes shallower with insertion of the electrode. Consequently, when we increase the mirror magnetic field strength and insert the electrode into the plasma, the beam intensities of highly charged ions increase. (author)

  4. Small high cooling power space cooler

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, T. V.; Raab, J.; Durand, D.; Tward, E. [Northrop Grumman Aerospace Systems Redondo Beach, Ca, 90278 (United States)

    2014-01-29

    The small High Efficiency pulse tube Cooler (HEC) cooler, that has been produced and flown on a number of space infrared instruments, was originally designed to provide cooling of 10 W @ 95 K. It achieved its goal with >50% margin when limited by the 180 W output ac power of its flight electronics. It has also been produced in 2 stage configurations, typically for simultaneously cooling of focal planes to temperatures as low as 35 K and optics at higher temperatures. The need for even higher cooling power in such a low mass cryocooler is motivated by the advent of large focal plane arrays. With the current availability at NGAS of much larger power cryocooler flight electronics, reliable long term operation in space with much larger cooling powers is now possible with the flight proven 4 kg HEC mechanical cooler. Even though the single stage cooler design can be re-qualified for those larger input powers without design change, we redesigned both the linear and coaxial version passive pulse tube cold heads to re-optimize them for high power cooling at temperatures above 130 K while rejecting heat to 300 K. Small changes to the regenerator packing, the re-optimization of the tuned inertance and no change to the compressor resulted in the increased performance at 150 K. The cooler operating at 290 W input power achieves 35 W@ 150 K corresponding to a specific cooling power at 150 K of 8.25 W/W and a very high specific power of 72.5 W/Kg. At these powers the cooler still maintains large stroke, thermal and current margins. In this paper we will present the measured data and the changes to this flight proven cooler that were made to achieve this increased performance.

  5. Advances in High Power Calorimetric Matched Loads for Short Pulses and CW Gyrotrons

    International Nuclear Information System (INIS)

    Bin, W.M.; Bruschi, A.; Cirant, S.; Gandini, F.; Granucci, G.; Mellera, V.; Muzzini, V.; Nardone, A.; Sozzi, C.; Spinicchia, N.

    2006-01-01

    the CW version at 2 MW, 170 GHz, are described in the paper. High power tests on short-pulse loads have been done using a double frequency gyrotron, 105 GHz/600 kW for 0.5 s and 140 GHz/800 kW for 1 s. Also a method for emulating 2 MW conditions while using 1 MW gyrotron has been applied for testing the load to be used for the European 2 MW coaxial cavity gyrotron development programme. (author)

  6. Performance of AlGaN/GaN Heterostructure Field-Effect Transistors for High-Frequency and High-Power Electronics

    Directory of Open Access Journals (Sweden)

    Peter Kordos

    2005-01-01

    Full Text Available Preparation and properties of GaN-based heterostructure field-effect transistors (HFETs for high-frequency and high-power applications are studied in this work. Performance of unpassivated and SiO2 passivated AlGaN/GaN HFETs, as well as passivated SiO2/AlGaN/GaN MOSHFETs (metal-oxide-semicondutor HFETs is compared. It is found that MOSHFETs exhibit better DC and RF properties than simple HFET counterparts. Deposited SiO2 yielded an increase of the sheet carrier density from 7.6x10^12 cm^-2 to 9.2x10^12 cm^-2 and subsequent increase of the static drain saturation current from 0.75 A/mm to 1.09 A/mm. Small-signal RF characterisation of MOSHFETs showed an extrinsic current gain cut-off frequency fT of 24 GHz and a maximum frequency of oscillation fmax of 40 GHz. These are fully comparable values with state-of-the-art AlGaN/GaN HFETs. Finnaůůy, microwave power measurements confirmed excellent performance of MOSHFETs:the output power measured at 7 GHz is about two-times larger than that of simple unpassived HFET. Thus, a great potential in application of GaN-based MOSHFETs is documented. 

  7. High power neutral beam injection in LHD

    International Nuclear Information System (INIS)

    Tsumori, K.; Takeiri, Y.; Nagaoka, K.

    2005-01-01

    The results of high power injection with a neutral beam injection (NBI) system for the large helical device (LHD) are reported. The system consists of three beam-lines, and two hydrogen negative ion (H - ion) sources are installed in each beam-line. In order to improve the injection power, the new beam accelerator with multi-slot grounded grid (MSGG) has been developed and applied to one of the beam-lines. Using the accelerator, the maximum powers of 5.7 MW were achieved in 2003 and 2004, and the energy of 189 keV reached at maximum. The power and energy exceeded the design values of the individual beam-line for LHD. The other beam-lines also increased their injection power up to about 4 MW, and the total injection power of 13.1 MW was achieved with three beam-lines in 2003. Although the accelerator had an advantage in high power beam injection, it involved a demerit in the beam focal condition. The disadvantage was resolved by modifying the aperture shapes of the steering grid. (author)

  8. High Flux Isotope Reactor power upgrade status

    International Nuclear Information System (INIS)

    Rothrock, R.B.; Hale, R.E.; Cheverton, R.D.

    1997-01-01

    A return to 100-MW operation is being planned for the High Flux Isotope Reactor (HFIR). Recent improvements in fuel element manufacturing procedures and inspection equipment will be exploited to reduce hot spot and hot streak factors sufficiently to permit the power upgrade without an increase in primary coolant pressure. Fresh fuel elements already fabricated for future use are being evaluated individually for power upgrade potential based on their measured coolant channel dimensions

  9. A new coaxial high power microwave source based on dual beams

    International Nuclear Information System (INIS)

    Li, Yangmei; Zhang, Xiaoping; Qi, Zumin; Dang, Fangchao; Qian, Baoliang

    2014-01-01

    We present a new coaxial high power microwave source based on dual beams, which combines a relativistic backward wave oscillator (RBWO) (noted as the inner sub-source below) and a coaxial transit-time oscillator (TTO) (noted as the outer sub-source). The cathode consists of an inner and an outer annular cathode, which provides the inner and the outer annular electron beam for the sub-sources, respectively. Particle-in-cell (PIC) simulation results demonstrate that power conversion efficiencies of the two sub-sources with an identical frequency of 9.74 GHz are 29% and 25%, respectively. It is furthermore found that phase locking between the inner and the outer sub-sources can be realized, which suggests a feasibility to obtain a higher power output if the two microwave signals are coherently combined

  10. A new coaxial high power microwave source based on dual beams

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yangmei, E-mail: sunberry1211@hotmail.com; Zhang, Xiaoping; Qi, Zumin; Dang, Fangchao; Qian, Baoliang [College of Optoelectric Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

    2014-05-15

    We present a new coaxial high power microwave source based on dual beams, which combines a relativistic backward wave oscillator (RBWO) (noted as the inner sub-source below) and a coaxial transit-time oscillator (TTO) (noted as the outer sub-source). The cathode consists of an inner and an outer annular cathode, which provides the inner and the outer annular electron beam for the sub-sources, respectively. Particle-in-cell (PIC) simulation results demonstrate that power conversion efficiencies of the two sub-sources with an identical frequency of 9.74 GHz are 29% and 25%, respectively. It is furthermore found that phase locking between the inner and the outer sub-sources can be realized, which suggests a feasibility to obtain a higher power output if the two microwave signals are coherently combined.

  11. Mixed-mode distribution systems for high average power electron cyclotron heating

    International Nuclear Information System (INIS)

    White, T.L.; Kimrey, H.D.; Bigelow, T.S.

    1984-01-01

    The ELMO Bumpy Torus-Scale (EBT-S) experiment consists of 24 simple magnetic mirrors joined end-to-end to form a torus of closed magnetic field lines. In this paper, we first describe an 80% efficient mixed-mode unpolarized heating system which couples 28-GHz microwave power to the midplane of the 24 EBT-S cavities. The system consists of two radiused bends feeding a quasi-optical mixed-mode toroidal distribution manifold. Balancing power to the 24 cavities is determined by detailed computer ray tracing. A second 28-GHz electron cyclotron heating (ECH) system using a polarized grid high field launcher is described. The launcher penetrates the fundamental ECH resonant surface without a vacuum window with no observable breakdown up to 1 kW/cm 2 (source limited) with 24 kW delivered to the plasma. This system uses the same mixed-mode output as the first system but polarizes the launched power by using a grid of WR42 apertures. The efficiency of this system is 32%, but can be improved by feeding multiple launchers from a separate distribution manifold

  12. Advanced High Voltage Power Device Concepts

    CERN Document Server

    Baliga, B Jayant

    2012-01-01

    Advanced High Voltage Power Device Concepts describes devices utilized in power transmission and distribution equipment, and for very high power motor control in electric trains and steel-mills. Since these devices must be capable of supporting more than 5000-volts in the blocking mode, this books covers operation of devices rated at 5,000-V, 10,000-V and 20,000-V. Advanced concepts (the MCT, the BRT, and the EST) that enable MOS-gated control of power thyristor structures are described and analyzed in detail. In addition, detailed analyses of the silicon IGBT, as well as the silicon carbide MOSFET and IGBT, are provided for comparison purposes. Throughout the book, analytical models are generated to give a better understanding of the physics of operation for all the structures. This book provides readers with: The first comprehensive treatment of high voltage (over 5000-volts) power devices suitable for the power distribution, traction, and motor-control markets;  Analytical formulations for all the device ...

  13. Studies of extraction and transport system for highly charged ion beam of 18 GHz superconducting electron cyclotron resonance ion source at Research Center for Nuclear Physics.

    Science.gov (United States)

    Yorita, T; Hatanaka, K; Fukuda, M; Ueda, H; Yasuda, Y; Morinobu, S; Tamii, A; Kamakura, K

    2014-02-01

    An 18 GHz superconducting electron cyclotron resonance ion source is installed to increase beam currents and to extend the variety of ions especially for highly charged heavy ions which can be accelerated by cyclotrons of Research Center for Nuclear Physics (RCNP), Osaka University. The beam production developments of several ions from B to Xe have been already done [T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H.Okamura, and A. Tamii, Rev. Sci. Instrum. 79, 02A311 (2008) and T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H.Okamura, and A. Tamii, Rev. Sci. Instrum. 81, 02A332 (2010)] and the further studies for those beam extraction and its transport have been done in order to increase the beam current more. The plasma electrode, extraction electrode, and einzel lens are modified. Especially extraction electrode can be applied minus voltage for the beam extraction and it works well to improve the extracted beam current. The extraction voltage dependences of transmission and emittance also have been studied for beam current improvement which is injected into azimuthally varying field cyclotron at RCNP.

  14. Resonant excitation of high order modes in the 3.9 GHz cavity of the Linac Coherent Light Source

    Directory of Open Access Journals (Sweden)

    A. Lunin

    2018-02-01

    Full Text Available Construction of the Linac Coherent Light Source II (LCLS-II is underway for the world’s first hard x-ray free-electron laser. A central part of the LCLS-II project is a 4 GeV superconducting radio frequency electron linac that will operate in the continuous wave (cw mode. The linac is segmented into four sections named as L0, L1, L2, and L3. Two 3.9 GHz cryomodules, each housing of eight third-harmonic cavities similar to the cavities developed for the European X-ray Free Electron Laser (XFEL, will be used in section L1 of the linac for linearizing the longitudinal beam profile. In this paper, we present a study of trapped high order modes (HOMs excited by a cw electron beam in the third-harmonic cavities of the LCLS-II linac. A detailed comparison of the original XFEL design and the LCLS-II design with a modified end group is performed in order to estimate the effect of a reduced beam pipe aperture on the efficiency of HOM damping. Furthermore, we apply a statistical analysis of the eigenmode spectrum for the estimation of the probability of resonant HOM losses and influence of HOMs on beam dynamics.

  15. Optimizing the design of very high power, high performance converters

    International Nuclear Information System (INIS)

    Edwards, R.J.; Tiagha, E.A.; Ganetis, G.; Nawrocky, R.J.

    1980-01-01

    This paper describes how various technologies are used to achieve the desired performance in a high current magnet power converter system. It is hoped that the discussions of the design approaches taken will be applicable to other power supply systems where stringent requirements in stability, accuracy and reliability must be met

  16. THz photonic wireless links with 16-QAM modulation in the 375-450 GHz band

    DEFF Research Database (Denmark)

    Jia, Shi; Yu, Xianbin; Hu, Hao

    2016-01-01

    forward error correction (HD-FEC) threshold of 3.8e-3 with 7% overhead. In addition, we also successfully demonstrate hybrid photonic wireless transmission of 40 Gbit/s 16-QAM signal at carrier frequencies of 400 GHz and 425 GHz over 30 km standard single mode fiber (SSMF) between the optical baseband...... signal transmitter and the THz wireless transmitter with negligible induced power penalty.......We propose and experimentally demonstrate THz photonic wireless communication systems with 16-QAM modulation in the 375-450 GHz band. The overall throughput reaches as high as 80 Gbit/s by exploiting four THz channels with 5 Gbaud 16-QAM baseband modulation per channel. We create a coherent optical...

  17. 100 GHz Externally Modulated Laser for Optical Interconnects Applications

    DEFF Research Database (Denmark)

    Ozolins, Oskars; Pang, Xiaodan; Iglesias Olmedo, Miguel

    2017-01-01

    We report on a 116 Gb/s on-off keying (OOK), four pulse amplitude modulation (PAM) and 105-Gb/s 8-PAM optical transmitter using an InP-based integrated and packaged externally modulated laser for high-speed optical interconnects with up to 30 dB static extinction ratio and over 100-GHz 3-d......B bandwidth with 2 dB ripple. In addition, we study the tradeoff between power penalty and equalizer length to foresee transmission distances with standard single mode fiber....

  18. The Jefferson Lab High Power Light Source

    Energy Technology Data Exchange (ETDEWEB)

    James R. Boyce

    2006-01-01

    Jefferson Lab has designed, built and operated two high average power free-electron lasers (FEL) using superconducting RF (SRF) technology and energy recovery techniques. Between 1999-2001 Jefferson Lab operated the IR Demo FEL. This device produced over 2 kW in the mid-infrared, in addition to producing world record average powers in the visible (50 W), ultraviolet (10 W) and terahertz range (50 W) for tunable, short-pulse (< ps) light. This FEL was the first high power demonstration of an accelerator configuration that is being exploited for a number of new accelerator-driven light source facilities that are currently under design or construction. The driver accelerator for the IR Demo FEL uses an Energy Recovered Linac (ERL) configuration that improves the energy efficiency and lowers both the capital and operating cost of such devices by recovering most of the power in the spent electron beam after optical power is extracted from the beam. The IR Demo FEL was de-commissioned in late 2001 for an upgraded FEL for extending the IR power to over 10 kW and the ultraviolet power to over 1 kW. The FEL Upgrade achieved 10 kW of average power in the mid-IR (6 microns) in July of 2004, and its IR operation currently is being extended down to 1 micron. In addition, we have demonstrated the capability of on/off cycling and recovering over a megawatt of electron beam power without diminishing machine performance. A complementary UV FEL will come on-line within the next year. This paper presents a summary of the FEL characteristics, user community accomplishments with the IR Demo, and planned user experiments.

  19. High power infrared QCLs: advances and applications

    Science.gov (United States)

    Patel, C. Kumar N.

    2012-01-01

    QCLs are becoming the most important sources of laser radiation in the midwave infrared (MWIR) and longwave infrared (LWIR) regions because of their size, weight, power and reliability advantages over other laser sources in the same spectral regions. The availability of multiwatt RT operation QCLs from 3.5 μm to >16 μm with wall plug efficiency of 10% or higher is hastening the replacement of traditional sources such as OPOs and OPSELs in many applications. QCLs can replace CO2 lasers in many low power applications. Of the two leading groups in improvements in QCL performance, Pranalytica is the commercial organization that has been supplying the highest performance QCLs to various customers for over four year. Using a new QCL design concept, the non-resonant extraction [1], we have achieved CW/RT power of >4.7 W and WPE of >17% in the 4.4 μm - 5.0 μm region. In the LWIR region, we have recently demonstrated QCLs with CW/RT power exceeding 1 W with WPE of nearly 10 % in the 7.0 μm-10.0 μm region. In general, the high power CW/RT operation requires use of TECs to maintain QCLs at appropriate operating temperatures. However, TECs consume additional electrical power, which is not desirable for handheld, battery-operated applications, where system power conversion efficiency is more important than just the QCL chip level power conversion efficiency. In high duty cycle pulsed (quasi-CW) mode, the QCLs can be operated without TECs and have produced nearly the same average power as that available in CW mode with TECs. Multiwatt average powers are obtained even in ambient T>70°C, with true efficiency of electrical power-to-optical power conversion being above 10%. Because of the availability of QCLs with multiwatt power outputs and wavelength range covering a spectral region from ~3.5 μm to >16 μm, the QCLs have found instantaneous acceptance for insertion into multitude of defense and homeland security applications, including laser sources for infrared

  20. The NASA CSTI High Capacity Power Program

    International Nuclear Information System (INIS)

    Winter, J.M.

    1991-09-01

    The SP-100 program was established in 1983 by DOD, DOE, and NASA as a joint program to develop the technology necessary for space nuclear power systems for military and civil applications. During 1986 and 1987, the NASA Advanced Technology Program was responsible for maintaining the momentum of promising technology advancement efforts started during Phase 1 of SP-100 and to strengthen, in key areas, the chances for successful development and growth capability of space nuclear reactor power systems for future space applications. In 1988, the NASA Advanced Technology Program was incorporated into NASA's new Civil Space Technology Initiative (CSTI). The CSTI program was established to provide the foundation for technology development in automation and robotics, information, propulsion, and power. The CSTI High Capacity Power Program builds on the technology efforts of the SP-100 program, incorporates the previous NASA advanced technology project, and provides a bridge to the NASA exploration technology programs. The elements of CSTI high capacity power development include conversion systems: Stirling and thermoelectric, thermal management, power management, system diagnostics, and environmental interactions. Technology advancement in all areas, including materials, is required to provide the growth capability, high reliability, and 7 to 10 year lifetime demanded for future space nuclear power systems. The overall program will develop and demonstrate the technology base required to provide a wide range of modular power systems while minimizing the impact of day/night operations as well as attitudes and distance from the Sun. Significant accomplishments in all of the program elements will be discussed, along with revised goals and project timelines recently developed

  1. High-power VCSELs for smart munitions

    Science.gov (United States)

    Geske, Jon; MacDougal, Michael; Cole, Garrett; Snyder, Donald

    2006-08-01

    The next generation of low-cost smart munitions will be capable of autonomously detecting and identifying targets aided partly by the ability to image targets with compact and robust scanning rangefinder and LADAR capabilities. These imaging systems will utilize arrays of high performance, low-cost semiconductor diode lasers capable of achieving high peak powers in pulses ranging from 5 to 25 nanoseconds in duration. Aerius Photonics is developing high-power Vertical-Cavity Surface-Emitting Lasers (VCSELs) to meet the needs of these smart munitions applications. The authors will report the results of Aerius' development program in which peak pulsed powers exceeding 60 Watts were demonstrated from single VCSEL emitters. These compact packaged emitters achieved pulse energies in excess of 1.5 micro-joules with multi kilo-hertz pulse repetition frequencies. The progress of the ongoing effort toward extending this performance to arrays of VCSEL emitters and toward further improving laser slope efficiency will be reported.

  2. High power all solid state VUV lasers

    International Nuclear Information System (INIS)

    Zhang, Shen-jin; Cui, Da-fu; Zhang, Feng-feng; Xu, Zhi; Wang, Zhi-min; Yang, Feng; Zong, Nan; Tu, Wei; Chen, Ying; Xu, Hong-yan; Xu, Feng-liang; Peng, Qin-jun; Wang, Xiao-yang; Chen, Chuang-tian; Xu, Zu-yan

    2014-01-01

    Highlights: • Polarization and pulse repetition rate adjustable ps 177.3 nm laser was developed. • Wavelength tunable ns, ps and fs VUV lasers were developed. • High power ns 177.3 nm laser with narrow linewidth was investigated. - Abstract: We report the investigation on the high power all solid state vacuum ultra-violet (VUV) lasers by means of nonlinear frequency conversion with KBe 2 BO 3 F 2 (KBBF) nonlinear crystal. Several all solid state VUV lasers have developed in our group, including polarization and pulse repetition rate adjustable picosecond 177.3 nm VUV laser, wavelength tunable nanosecond, picosecond and femtosecond VUV lasers, high power ns 177.3 nm laser with narrow linewidth. The VUV lasers have impact, accurate and precise advantage

  3. High Power High Efficiency Diode Laser Stack for Processing

    Science.gov (United States)

    Gu, Yuanyuan; Lu, Hui; Fu, Yueming; Cui, Yan

    2018-03-01

    High-power diode lasers based on GaAs semiconductor bars are well established as reliable and highly efficient laser sources. As diode laser is simple in structure, small size, longer life expectancy with the advantages of low prices, it is widely used in the industry processing, such as heat treating, welding, hardening, cladding and so on. Respectively, diode laser could make it possible to establish the practical application because of rectangular beam patterns which are suitable to make fine bead with less power. At this power level, it can have many important applications, such as surgery, welding of polymers, soldering, coatings and surface treatment of metals. But there are some applications, which require much higher power and brightness, e.g. hardening, key hole welding, cutting and metal welding. In addition, High power diode lasers in the military field also have important applications. So all developed countries have attached great importance to high-power diode laser system and its applications. This is mainly due their low performance. In this paper we will introduce the structure and the principle of the high power diode stack.

  4. High to ultra-high power electrical energy storage.

    Science.gov (United States)

    Sherrill, Stefanie A; Banerjee, Parag; Rubloff, Gary W; Lee, Sang Bok

    2011-12-14

    High power electrical energy storage systems are becoming critical devices for advanced energy storage technology. This is true in part due to their high rate capabilities and moderate energy densities which allow them to capture power efficiently from evanescent, renewable energy sources. High power systems include both electrochemical capacitors and electrostatic capacitors. These devices have fast charging and discharging rates, supplying energy within seconds or less. Recent research has focused on increasing power and energy density of the devices using advanced materials and novel architectural design. An increase in understanding of structure-property relationships in nanomaterials and interfaces and the ability to control nanostructures precisely has led to an immense improvement in the performance characteristics of these devices. In this review, we discuss the recent advances for both electrochemical and electrostatic capacitors as high power electrical energy storage systems, and propose directions and challenges for the future. We asses the opportunities in nanostructure-based high power electrical energy storage devices and include electrochemical and electrostatic capacitors for their potential to open the door to a new regime of power energy.

  5. ALMA 690 GHz OBSERVATIONS OF IRAS 16293–2422B: INFALL IN A HIGHLY OPTICALLY THICK DISK

    International Nuclear Information System (INIS)

    Zapata, Luis A.; Loinard, Laurent; Rodríguez, Luis F.; Hernández-Hernández, Vicente; Takahashi, Satoko; Trejo, Alfonso; Parise, Bérengère

    2013-01-01

    We present sensitive, high angular resolution (∼0.''2) submillimeter continuum and line observations of IRAS 16293–2422B made with the Atacama Large Millimeter/Submillimeter Array. The 0.45 mm continuum observations reveal a single and very compact source associated with IRAS 16293–2422B. This submillimeter source has a deconvolved angular size of about 400 mas (50 AU) and does not show any inner structure inside of this diameter. The H 13 CN, HC 15 N, and CH 3 OH line emission regions are about twice as large as the continuum emission and reveal a pronounced inner depression or ''hole'' with a size comparable to that estimated for the submillimeter continuum. We suggest that the presence of this inner depression and the fact that we do not see an inner structure (or a flat structure) in the continuum are produced by very optically thick dust located in the innermost parts of IRAS 16293–2422B. All three lines also show pronounced inverse P-Cygni profiles with infall and dispersion velocities larger than those recently reported from observations at lower frequencies, suggesting that we are detecting faster and more turbulent gas located closer to the central object. Finally, we report a small east-west velocity gradient in IRAS 16293–2422B that suggests that its disk plane is likely located very close to the plane of the sky.

  6. Two-stage, high power X-band amplifier experiment

    International Nuclear Information System (INIS)

    Kuang, E.; Davis, T.J.; Ivers, J.D.; Kerslick, G.S.; Nation, J.A.; Schaechter, L.

    1993-01-01

    At output powers in excess of 100 MW the authors have noted the development of sidebands in many TWT structures. To address this problem an experiment using a narrow bandwidth, two-stage TWT is in progress. The TWT amplifier consists of a dielectric (e = 5) slow-wave structure, a 30 dB sever section and a 8.8-9.0 GHz passband periodic, metallic structure. The electron beam used in this experiment is a 950 kV, 1 kA, 50 ns pencil beam propagating along an applied axial field of 9 kG. The dielectric first stage has a maximum gain of 30 dB measured at 8.87 GHz, with output powers of up to 50 MW in the TM 01 mode. In these experiments the dielectric amplifier output power is about 3-5 MW and the output power of the complete two-stage device is ∼160 MW at the input frequency. The sidebands detected in earlier experiments have been eliminated. The authors also report measurements of the energy spread of the electron beam resulting from the amplification process. These experimental results are compared with MAGIC code simulations and analytic work they have carried out on such devices

  7. Powersail High Power Propulsion System Design Study

    Science.gov (United States)

    Gulczinski, Frank S., III

    2000-11-01

    A desire by the United States Air Force to exploit the space environment has led to a need for increased on-orbit electrical power availability. To enable this, the Air Force Research Laboratory Space Vehicles Directorate (AFRL/ VS) is developing Powersail: a two-phased program to demonstrate high power (100 kW to 1 MW) capability in space using a deployable, flexible solar array connected to the host spacecraft using a slack umbilical. The first phase will be a proof-of-concept demonstration at 50 kW, followed by the second phase, an operational system at full power. In support of this program, the AFRL propulsion Directorate's Spacecraft Propulsion Branch (AFRL/PRS ) at Edwards AFB has commissioned a design study of the Powersail High Power Propulsion System. The purpose of this study, the results of which are summarized in this paper, is to perform mission and design trades to identify potential full-power applications (both near-Earth and interplanetary) and the corresponding propulsion system requirements and design. The design study shall farther identify a suitable low power demonstration flight that maximizes risk reduction for the fully operational system. This propulsion system is expected to be threefold: (1) primary propulsion for moving the entire vehicle, (2) a propulsion unit that maintains the solar array position relative to the host spacecraft, and (3) control propulsion for maintaining proper orientation for the flexible solar array.

  8. Reactor G1: high power experiments

    International Nuclear Information System (INIS)

    Laage, F. de; Teste du Baillet, A.; Veyssiere, A.; Wanner, G.

    1957-01-01

    The experiments carried out in the starting-up programme of the reactor G1 comprised a series of tests at high power, which allowed the following points to be studied: 1- Effect of poisoning by Xenon (absolute value, evolution). 2- Temperature coefficients of the uranium and graphite for a temperature distribution corresponding to heating by fission. 3- Effect of the pressure (due to the coiling system) on the reactivity. 4- Calibration of the security rods as a function of their position in the pile (1). 5- Temperature distribution of the graphite, the sheathing, the uranium and the air leaving the canals, in a pile running normally at high power. 6- Neutron flux distribution in a pile running normally at high power. 7- Determination of the power by nuclear and thermodynamic methods. These experiments have been carried out under two very different pile conditions. From the 1. to the 15. of August 1956, a series of power increases, followed by periods of stabilisation, were induced in a pile containing uranium only, in 457 canals, amounting to about 34 tons of fuel. A knowledge of the efficiency of the control rods in such a pile has made it possible to measure with good accuracy the principal effects at high temperatures, that is, to deal with points 1, 2, 3, 5. Flux charts giving information on the variations of the material Laplacian and extrapolation lengths in the reflector have been drawn up. Finally the thermodynamic power has been measured under good conditions, in spite of some installation difficulties. On September 16, the pile had its final charge of 100 tons. All the canals were loaded, 1,234 with uranium and 53 (i.e. exactly 4 per cent of the total number) with thorium uniformly distributed in a square lattice of 100 cm side. Since technical difficulties prevented the calibration of the control rods, the measurements were limited to the determination of the thermodynamic power and the temperature distributions (points 5 and 7). This report will

  9. Compact high-power terahertz radiation source

    Directory of Open Access Journals (Sweden)

    G. A. Krafft

    2004-06-01

    Full Text Available In this paper a new type of THz radiation source, based on recirculating an electron beam through a high gradient superconducting radio frequency cavity, and using this beam to drive a standard electromagnetic undulator on the return leg, is discussed. Because the beam is recirculated and not stored, short bunches may be produced that radiate coherently in the undulator, yielding exceptionally high average THz power for relatively low average beam power. Deceleration from the coherent emission, and the detuning it causes, limits the charge-per-bunch possible in such a device.

  10. High power RF transmission line component development

    International Nuclear Information System (INIS)

    Hong, B. G.; Hwang, C. K.; Bae, Y. D.; Yoon, J. S.; Wang, S. J.; Gu, S. H.; Yang, J. R.; Hahm, Y. S.; Oh, G. S.; Lee, J. R.; Lee, W. I.; Park, S. H.; Kang, M. S.; Oh, S. H.; Lee, W.I.

    1999-12-01

    We developed the liquid stub and phase shifter which are the key high RF power transmission line components. They show reliable operation characteristics and increased insulation capability, and reduced the size by using liquid (silicon oil, dielectric constant ε=2.72) instead of gas for insulating dielectric material. They do not have finger stock for the electric contact so the local temperature rise due to irregular contact and RF breakdown due to scratch in conductor are prevented. They can be utilized in broadcasting, radar facility which require high RF power transmission. Moreover, they are key components in RF heating system for fusion reactor. (author)

  11. High power RF transmission line component development

    Energy Technology Data Exchange (ETDEWEB)

    Hong, B. G.; Hwang, C. K.; Bae, Y. D.; Yoon, J. S.; Wang, S. J.; Gu, S. H.; Yang, J. R.; Hahm, Y. S.; Oh, G. S.; Lee, J. R.; Lee, W. I.; Park, S. H.; Kang, M. S.; Oh, S. H.; Lee, W.I

    1999-12-01

    We developed the liquid stub and phase shifter which are the key high RF power transmission line components. They show reliable operation characteristics and increased insulation capability, and reduced the size by using liquid (silicon oil, dielectric constant {epsilon}=2.72) instead of gas for insulating dielectric material. They do not have finger stock for the electric contact so the local temperature rise due to irregular contact and RF breakdown due to scratch in conductor are prevented. They can be utilized in broadcasting, radar facility which require high RF power transmission. Moreover, they are key components in RF heating system for fusion reactor. (author)

  12. High voltage superconducting switch for power application

    International Nuclear Information System (INIS)

    Mawardi, O.; Ferendeci, A.; Gattozzi, A.

    1983-01-01

    This paper reports the development of a novel interrupter which meets the requirements of a high voltage direct current (HVDC) power switch and at the same time doubles as a current limiter. The basic concept of the interrupter makes use of a fast superconducting, high capacity (SHIC) switch that carries the full load current while in the superconducting state and reverts to the normal resistive state when triggered. Typical design parameters are examined for the case of a HVDC transmission line handling 2.5KA at 150KVDC. The result is a power switch with superior performance and smaller size than the ones reported to date

  13. Advances in Very High Frequency Power Conversion

    DEFF Research Database (Denmark)

    Kovacevic, Milovan

    Resonant and quasi-resonant converters operated at frequencies above 30 MHz have attracted special attention in the last two decades. Compared to conventional converters operated at ~100 kHz, they offer significant advantages: smaller volume and weight, lower cost, and faster transient performance....... Excellent performance and small size of magnetic components and capacitors at very high frequencies, along with constant advances in performance of power semiconductor devices, suggests a sizable shift in consumer power supplies market into this area in the near future. To operate dc-dc converter power...... method provides low complexity and low gate loss simultaneously. A direct design synthesis method is provided for resonant SEPIC converters employing this technique. Most experimental prototypes were developed using low cost, commercially available power semiconductors. Due to very fast transient...

  14. Advanced Output Coupling for High Power Gyrotrons

    Energy Technology Data Exchange (ETDEWEB)

    Read, Michael [Calabazas Creek Research, Inc., San Mateo, CA (United States); Ives, Robert Lawrence [Calabazas Creek Research, Inc., San Mateo, CA (United States); Marsden, David [Calabazas Creek Research, Inc., San Mateo, CA (United States); Collins, George [Calabazas Creek Research, Inc., San Mateo, CA (United States); Temkin, Richard [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Guss, William [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Lohr, John [General Atomics, La Jolla, CA (United States); Neilson, Jeffrey [Lexam Research, Redwood City, CA (United States); Bui, Thuc [Calabazas Creek Research, Inc., San Mateo, CA (United States)

    2016-11-28

    The Phase II program developed an internal RF coupler that transforms the whispering gallery RF mode produced in gyrotron cavities to an HE11 waveguide mode propagating in corrugated waveguide. This power is extracted from the vacuum using a broadband, chemical vapor deposited (CVD) diamond, Brewster angle window capable of transmitting more than 1.5 MW CW of RF power over a broad range of frequencies. This coupling system eliminates the Mirror Optical Units now required to externally couple Gaussian output power into corrugated waveguide, significantly reducing system cost and increasing efficiency. The program simulated the performance using a broad range of advanced computer codes to optimize the design. Both a direct coupler and Brewster angle window were built and tested at low and high power. Test results confirmed the performance of both devices and demonstrated they are capable of achieving the required performance for scientific, defense, industrial, and medical applications.

  15. High Average Power, High Energy Short Pulse Fiber Laser System

    Energy Technology Data Exchange (ETDEWEB)

    Messerly, M J

    2007-11-13

    Recently continuous wave fiber laser systems with output powers in excess of 500W with good beam quality have been demonstrated [1]. High energy, ultrafast, chirped pulsed fiber laser systems have achieved record output energies of 1mJ [2]. However, these high-energy systems have not been scaled beyond a few watts of average output power. Fiber laser systems are attractive for many applications because they offer the promise of high efficiency, compact, robust systems that are turn key. Applications such as cutting, drilling and materials processing, front end systems for high energy pulsed lasers (such as petawatts) and laser based sources of high spatial coherence, high flux x-rays all require high energy short pulses and two of the three of these applications also require high average power. The challenge in creating a high energy chirped pulse fiber laser system is to find a way to scale the output energy while avoiding nonlinear effects and maintaining good beam quality in the amplifier fiber. To this end, our 3-year LDRD program sought to demonstrate a high energy, high average power fiber laser system. This work included exploring designs of large mode area optical fiber amplifiers for high energy systems as well as understanding the issues associated chirped pulse amplification in optical fiber amplifier systems.

  16. Status of an induction accelerator driven, high-power microwave generator at Livermore

    International Nuclear Information System (INIS)

    Houck, T.L.; Westenskow, G.A.

    1993-01-01

    The authors are testing an enhanced version of the Choppertron, a high-power rf generator which shows great promise of achieving greater than 400 MW of output power at 11.4 GHz with stable phase and amplitude. This version of the Choppertron is driven by a 5-MeV, 1-kA induction accelerator beam. Modifications to the original Choppertron included aggressive suppression of high order modes in the two output structures, lengthening of the modulation section to match for higher beam energy, and improved efficiency. Final results of the original Choppertron experiment, status of the ongoing experiment and planned experiments for the next year are presented. The motivation of the research program at the LLNL Microwave Source Facility is to develop microwave sources which could be suitable drivers for a future TeV linear e + e - collider

  17. High power switches for ion induction linacs

    International Nuclear Information System (INIS)

    Humphries, S.; Savage, M.; Saylor, W.B.

    1985-01-01

    The success of linear induction ion accelerators for accelerator inertial fusion (AIF) applications depends largely on innovations in pulsed power technology. There are tight constraints on the accuracy of accelerating voltage waveforms to maintain a low momentum spread. Furthermore, the non-relativistic ion beams may be subject to a klystronlike interaction with the accelerating cavities, leading to enhanced momentum spread. In this paper, we describe a novel high power switch with a demonstrated ability to interrupt 300 A at 20 kV in less than 60 ns. The switch may allow the replacement of pulse modulators in linear induction accelerators with hard tube pulsers. A power system based on a hard tube pulser could solve the longitudinal instability problem while maintaining high energy transfer efficiency. The problem of longitudinal beam control in ion induction linacs is reviewed in Section 2. Section 3 describes the principles of the plasma flow switch. Experimental results are summarized in Section 4

  18. High power switches for ion induction linacs

    International Nuclear Information System (INIS)

    Humphries, S. Jr.; Savage, M.; Saylor, W.B.

    1985-01-01

    The success of linear induction ion accelerators for accelerator inertial fusion (AIF) applications depends largely on innovations in pulsed power technology. There are tight constraints on the accuracy of accelerating voltage waveforms to maintain a low momentum spread. Furthermore, the non-relativistic ion beams may be subject to a klystron-like interaction with the accelerating cavities leading to enhanced momentum spread. In this paper, the author describe a novel high power switch with a demonstrated ability to interrupt 300 A at 20 kV in less than 60 ns. The switch may allow the replacement of pulse modulators in linear induction accelerators with hard tube pulsers. A power system based on a hard tube pulser could solve the longitudinal instability problem while maintaining high energy transfer efficiency. The problem of longitudinal beam control in ion induction linacs is reviewed in Section 2. Section 3 describes the principles of the plasma flow switch. Experimental results are summarized in Section 4

  19. High power RF oscillator with Marx generators

    International Nuclear Information System (INIS)

    Murase, Hiroshi; Hayashi, Izumi

    1980-01-01

    A method to maintain RF oscillation by using many Marx generators was proposed and studied experimentally. Many charging circuits were connected to an oscillator circuit, and successive pulsed charging was made. This successive charging amplified and maintained the RF oscillation. The use of vacuum gaps and high power silicon diodes improved the characteristics of RF current cut-off of the circuit. The efficiency of the pulsed charging from Marx generators to a condenser was theoretically investigated. The theoretical result showed the maximum efficiency of 0.98. The practical efficiency obtained by using a proposed circuit with a high power oscillator was in the range 0.50 to 0.56. The obtained effective output power of the RF pulses was 11 MW. The maximum holding time of the RF pulses was about 21 microsecond. (Kato, T.)

  20. Operation of Power Grids with High Penetration of Wind Power

    Science.gov (United States)

    Al-Awami, Ali Taleb

    The integration of wind power into the power grid poses many challenges due to its highly uncertain nature. This dissertation involves two main components related to the operation of power grids with high penetration of wind energy: wind-thermal stochastic dispatch and wind-thermal coordinated bidding in short-term electricity markets. In the first part, a stochastic dispatch (SD) algorithm is proposed that takes into account the stochastic nature of the wind power output. The uncertainty associated with wind power output given the forecast is characterized using conditional probability density functions (CPDF). Several functions are examined to characterize wind uncertainty including Beta, Weibull, Extreme Value, Generalized Extreme Value, and Mixed Gaussian distributions. The unique characteristics of the Mixed Gaussian distribution are then utilized to facilitate the speed of convergence of the SD algorithm. A case study is carried out to evaluate the effectiveness of the proposed algorithm. Then, the SD algorithm is extended to simultaneously optimize the system operating costs and emissions. A modified multi-objective particle swarm optimization algorithm is suggested to identify the Pareto-optimal solutions defined by the two conflicting objectives. A sensitivity analysis is carried out to study the effect of changing load level and imbalance cost factors on the Pareto front. In the second part of this dissertation, coordinated trading of wind and thermal energy is proposed to mitigate risks due to those uncertainties. The problem of wind-thermal coordinated trading is formulated as a mixed-integer stochastic linear program. The objective is to obtain the optimal tradeoff bidding strategy that maximizes the total expected profits while controlling trading risks. For risk control, a weighted term of the conditional value at risk (CVaR) is included in the objective function. The CVaR aims to maximize the expected profits of the least profitable scenarios, thus

  1. Optical engineering for high power laser applications

    International Nuclear Information System (INIS)

    Novaro, M.

    1993-01-01

    Laser facilities for Inertial Confinement Fusion (I.C.F.) experiments require laser and X ray optics able to withstand short pulse conditions. After a brief recall of high power laser system arrangements and of the characteristics of their optics, the authors will present some X ray optical developments

  2. Development of a high power femtosecond laser

    CSIR Research Space (South Africa)

    Neethling, PH

    2010-10-01

    Full Text Available The Laser Research Institute and the CSIR National Laser Centre are developing a high power femtosecond laser system in a joint project with a phased approach. The laser system consists of an fs oscillator and a regenerative amplifier. An OPCPA...

  3. Targets for high power neutral beams

    International Nuclear Information System (INIS)

    Kim, J.

    1980-01-01

    Stopping high-power, long-pulse beams is fast becoming an engineering challenge, particularly in neutral beam injectors for heating magnetically confined plasmas. A brief review of neutral beam target technology is presented along with heat transfer calculations for some selected target designs

  4. Reduced filamentation in high power semiconductor lasers

    DEFF Research Database (Denmark)

    Skovgaard, Peter M. W.; McInerney, John; O'Brien, Peter

    1999-01-01

    High brightness semiconductor lasers have applications in fields ranging from material processing to medicine. The main difficulty associated with high brightness is that high optical power densities cause damage to the laser facet and thus require large apertures. This, in turn, results in spatio......-temporal instabilities such as filamentation which degrades spatial coherence and brightness. We first evaluate performance of existing designs with a “top-hat” shaped transverse current density profile. The unstable nature of highly excited semiconductor material results in a run-away process where small modulations...

  5. High Efficiency Reversible Fuel Cell Power Converter

    DEFF Research Database (Denmark)

    Pittini, Riccardo

    as well as different dc-ac and dc-dc converter topologies are presented and analyzed. A new ac-dc topology for high efficiency data center applications is proposed and an efficiency characterization based on the fuel cell stack I-V characteristic curve is presented. The second part discusses the main...... converter components. Wide bandgap power semiconductors are introduced due to their superior performance in comparison to traditional silicon power devices. The analysis presents a study based on switching loss measurements performed on Si IGBTs, SiC JFETs, SiC MOSFETs and their respective gate drivers...

  6. Performance and operation of advanced superconducting electron cyclotron resonance ion source SECRAL at 24 GHz

    International Nuclear Information System (INIS)

    Zhao, H. W.; Zhang, X. Z.; Feng, Y. C.; Guo, J. W.; Li, J. Y.; Guo, X. H.; Sha, S.; Sun, L. T.; Xie, D. Z.; Lu, W.; Cao, Y.

    2012-01-01

    SECRAL (superconducting ECR ion source with advanced design in Lanzhou) ion source has been in routine operation for Heavy Ion Research Facility in Lanzhou (HIRFL) accelerator complex since May 2007. To further enhance the SECRAL performance in order to satisfy the increasing demand for intensive highly charged ion beams, 3-5 kW high power 24 GHz single frequency and 24 GHz +18 GHz double frequency with an aluminum plasma chamber were tested, and some exciting results were produced with quite a few new record highly charged ion beam intensities, such as 129 Xe 35+ of 64 eμA, 129 Xe 42+ of 3 eμA, 209 Bi 41+ of 50 eμA, 209 Bi 50+ of 4.3 eμA and 209 Bi 54+ of 0.2 eμA. In most cases SECRAL is operated at 18 GHz to deliver highly charged heavy ion beams for the HIRFL accelerator, only for those very high charge states and very heavy ion beams such as 209 Bi 36+ and 209 Bi 41+ , SECRAL has been operated at 24 GHz. The total operation beam time provided by SECRAL up to July 2011 has exceeded 7720 hours. In this paper, the latest performance, development, and operation status of SECRAL ion source are presented. The latest results and reliable long-term operation for the HIRFL accelerator have demonstrated that SECRAL performance for production of highly charged heavy ion beams remains improving at higher RF power with optimized tuning.

  7. Design and development of high voltage high power operational ...

    Indian Academy of Sciences (India)

    address this challenge, a) Designing a discrete power opamp with high .... the use of high-impedance feedback networks, thus minimizing their output loading ... Spice simulation is done for the circuit and results are given in figures 4a–c.

  8. Voltage generators of high voltage high power accelerators

    International Nuclear Information System (INIS)

    Svinin, M.P.

    1981-01-01

    High voltage electron accelerators are widely used in modern radiation installations for industrial purposes. In the near future further increasing of their power may be effected, which enables to raise the efficiency of the radiation processes known and to master new power-consuming production in industry. Improvement of HV generators by increasing their power and efficiency is one of many scientific and engineering aspects the successful solution of which provides further development of these accelerators and their technical parameters. The subject is discussed in detail. (author)

  9. High impact data visualization with Power View, Power Map, and Power BI

    CERN Document Server

    Aspin, Adam

    2014-01-01

    High Impact Data Visualization with Power View, Power Map, and Power BI helps you take business intelligence delivery to a new level that is interactive, engaging, even fun, all while driving commercial success through sound decision-making. Learn to harness the power of Microsoft's flagship, self-service business intelligence suite to deliver compelling and interactive insight with remarkable ease. Learn the essential techniques needed to enhance the look and feel of reports and dashboards so that you can seize your audience's attention and provide them with clear and accurate information. Al

  10. A High Power Linear Solid State Pulser

    International Nuclear Information System (INIS)

    Boris Yen; Brent Davis; Rex Booth

    1999-01-01

    Particle Accelerators require high voltage and often high power. Typically the high voltage/power generation utilizes a topology with an extra energy store and a switching means to extract that stored energy. The switches may be active or passive devices. Active switches are hard or soft vacuum tubes, or semiconductors. When required voltages exceed tens of kilovolts, numerous semiconductors are stacked to withstand that potential. Such topologies can use large numbers of critical parts that, when in series, compromise the system reliability and performance. This paper describes a modular, linear, solid state amplifier which uses a parallel array of semiconductors, coupled with transmission line transformers. Such a design can provide output signals with voltages exceeding 10kV (into 50-ohms), and with rise and fall times (10-90 % amplitude) that are less than 1--ns. This compact solid state amplifier is modular, and has both hot-swap and soft fail capabilities

  11. High prices on electric power now again?

    International Nuclear Information System (INIS)

    Doorman, Gerard

    2003-01-01

    Deregulation of the electric power market has yielded low prices for the consumers throughout the 1990s. Consumption has now increased considerably, but little new production has been added. This results in high prices in dry years, but to understand this one must understand price formation in the Nordic spot market. The high prices are a powerful signal to the consumers to reduce consumption, but they are also a signal to the producers to seize any opportunity to increase production. However, the construction of new dams etc. stirs up the environmentalists. Ordinary consumers may protect themselves against high prices by signing fixed-price contracts. For those who can tolerate price fluctuations, spot prices are a better alternative than the standard contract with variable price

  12. High average power linear induction accelerator development

    International Nuclear Information System (INIS)

    Bayless, J.R.; Adler, R.J.

    1987-07-01

    There is increasing interest in linear induction accelerators (LIAs) for applications including free electron lasers, high power microwave generators and other types of radiation sources. Lawrence Livermore National Laboratory has developed LIA technology in combination with magnetic pulse compression techniques to achieve very impressive performance levels. In this paper we will briefly discuss the LIA concept and describe our development program. Our goals are to improve the reliability and reduce the cost of LIA systems. An accelerator is presently under construction to demonstrate these improvements at an energy of 1.6 MeV in 2 kA, 65 ns beam pulses at an average beam power of approximately 30 kW. The unique features of this system are a low cost accelerator design and an SCR-switched, magnetically compressed, pulse power system. 4 refs., 7 figs

  13. Visible high power fiber coupled diode lasers

    Science.gov (United States)

    Köhler, Bernd; Drovs, Simon; Stoiber, Michael; Dürsch, Sascha; Kissel, Heiko; Könning, Tobias; Biesenbach, Jens; König, Harald; Lell, Alfred; Stojetz, Bernhard; Löffler, Andreas; Strauß, Uwe

    2018-02-01

    In this paper we report on further development of fiber coupled high-power diode lasers in the visible spectral range. New visible laser modules presented in this paper include the use of multi single emitter arrays @ 450 nm leading to a 120 W fiber coupled unit with a beam quality of 44 mm x mrad, as well as very compact modules with multi-W output power from 405 nm to 640 nm. However, as these lasers are based on single emitters, power scaling quickly leads to bulky laser units with a lot of optical components to be aligned. We also report on a new approach based on 450 nm diode laser bars, which dramatically reduces size and alignment effort. These activities were performed within the German government-funded project "BlauLas": a maximum output power of 80 W per bar has been demonstrated @ 450 nm. We show results of a 200 μm NA0.22 fiber coupled 35 W source @ 450 nm, which has been reduced in size by a factor of 25 compared to standard single emitter approach. In addition, we will present a 200 μm NA0.22 fiber coupled laser unit with an output power of 135 W.

  14. Handoff Management in Radio over Fiber 60 GHz Indoor Networks

    NARCIS (Netherlands)

    Bien, V.Q.

    2014-01-01

    Because of high data rate multimedia applications such as HD and UHDTV, online games, etc., the future home networks are expected to support short-range gigabit transmission. With the worldwide availability of 5 GHz spectrum at the 60 GHz band, it creates the opportunity for a promising air

  15. High power VCSELs for miniature optical sensors

    Science.gov (United States)

    Geske, Jon; Wang, Chad; MacDougal, Michael; Stahl, Ron; Follman, David; Garrett, Henry; Meyrath, Todd; Snyder, Don; Golden, Eric; Wagener, Jeff; Foley, Jason

    2010-02-01

    Recent advances in Vertical-cavity Surface-emitting Laser (VCSEL) efficiency and packaging have opened up alternative applications for VCSELs that leverage their inherent advantages over light emitting diodes and edge-emitting lasers (EELs), such as low-divergence symmetric emission, wavelength stability, and inherent 2-D array fabrication. Improvements in reproducible highly efficient VCSELs have allowed VCSELs to be considered for high power and high brightness applications. In this talk, Aerius will discuss recent advances with Aerius' VCSELs and application of these VCSELs to miniature optical sensors such as rangefinders and illuminators.

  16. Integrated 60GHz RF Beamforming in CMOS

    NARCIS (Netherlands)

    Yu, Yikun; Baltus, P.G.M.; Roermund, van A.H.M.

    2011-01-01

    The 60GHz band is promising for applications such as high-speed short-range wireless personal area network (WPAN), real time video streaming at rates of several Gbps, automotive radar, and mm-Wave imaging, since it provides a large amount of bandwidth that can freely (i.e. without a license) be used

  17. Characteristics of a four element gyromagnetic nonlinear transmission line array high power microwave source

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J. M., E-mail: jared.johnson@ttu.edu; Reale, D. V.; Garcia, R. S.; Cravey, W. H.; Neuber, A. A.; Dickens, J. C.; Mankowski, J. J. [Center for Pulsed Power and Power Electronics Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, Texas 79409 (United States); Krile, J. T. [Department of Electromagnetics and Sensor Systems, Naval Surface Warfare Center - Dahlgren Division, Dahlgren, Virginia 22448 (United States)

    2016-05-15

    In this paper, a solid-state four element array gyromagnetic nonlinear transmission line high power microwave system is presented as well as a detailed description of its subsystems and general output capabilities. This frequency agile S-band source is easily adjusted from 2-4 GHz by way of a DC driven biasing magnetic field and is capable of generating electric fields of 7.8 kV/m at 10 m correlating to 4.2 MW of RF power with pulse repetition frequencies up to 1 kHz. Beam steering of the array at angles of ±16.7° is also demonstrated, and the associated general radiation pattern is detailed.

  18. Novel method to improve power handling capability for coplanar waveguide high-temperature superconducting filter

    Energy Technology Data Exchange (ETDEWEB)

    Satoh, K; Koizumi, D; Narahashi, S [NTT DoCoMo, Inc., 3-5 Hikari-no-oka, 239-8536 Yokosuka (Japan)

    2006-06-01

    This paper proposes a novel method to improve the power handling capability of a coplanar waveguide (CPW) high-temperature superconducting (HTS) filter. The noteworthy point of the proposed method is that it is based on the concept that the power handling capability is improved by reducing the maximum current density of the filter. Numerical investigations confirm that a CPW HTS filter using 66-{omega} characteristic impedance resonators (66-{omega} CPW HTSF) reduces the maximum current density compared to that using conventional 50-{omega} resonators (50-{omega} CPW HTSF). We fabricated 5-GHz band four-pole Chevyshev CPW HTSFs based on the proposed and conventional methods. The fabricated 66-{omega} CPW HTSF exhibited the third-order intercept point (TOI) of + 61 dBm while the 50-{omega} CPW HTSF exhibited the TOI of + 54 dBm, both at 60 K. These results indicate the effectiveness of the proposed method.

  19. High power tests of beryllium oxide windows to the lower hybrid current drive launcher in JET

    International Nuclear Information System (INIS)

    Ekedahl, A.; Brandon, M.; Finburg, P.

    1999-01-01

    The vacuum windows to the 3.70 GHz Lower Hybrid Current Drive (LHCD) system in JET were originally designed to withstand 350 kW for 20 s with VSWR ≤ 1.8. High power RF tests of the windows have been carried out in the LHCD test facility at JET. All windows that were tested could operate at 500 kW for 10 s in a matched load. Two windows passed an endurance test at 250 kW for 20 s with the windows terminated in a short circuit. One window also passed this endurance test without active cooling. The results show that this type of window can be used in a new advanced launcher, as proposed for ITER, in which the output power from each klystron (P ≤ 500 kW) will be transmitted through one waveguide and one vacuum window. (author)

  20. First lasing of the Dutch Fusion-FEM: 730 kW, 200 GHz

    Energy Technology Data Exchange (ETDEWEB)

    Urbanus, W.H. E-mail: urbanus@rijnh.nl; Bongers, W.A.; Geer, C.A.J. van der; Manintveld, P.; Plomp, J.; Pluygers, J.; Poelman, A.J.; Smeets, P.H.M.; Schueller, F.C.; Verhoeven, A.G.A.; Bratman, V.L.; Denisov, G.G.; Savilov, A.V.; Shmelyov, M.Yu.; Caplan, M.; Varfolomeev, A.A

    1999-06-01

    A high-power electrostatic free-electron maser is operated at various frequencies. An output power of 730 kW at 206 GHz is generated with a 7.2 A, 1.77 MeV electron beam, and 360 kW at 167 GHz is generated with a 7.0 A, 1.61 MeV electron beam. It is shown experimentally and by simulations that, depending on the electron beam energy, the FEM can operate in single-frequency regime. First experiments were done without electron beam energy recovery system, and the pulse length was limited to 12 {mu}s. Nevertheless, many aspects of generation of mm-wave power have been explored, such as the dependency on the electron beam energy and beam current and cavity settings such as the feedback coefficient. The achieved parameters and the FEM dynamics are in good accordance with simulations.

  1. 8. High power laser and ignition facilities

    International Nuclear Information System (INIS)

    Bayramian, A.J.; Beach, R.J.; Bibeau, C.

    2002-01-01

    This document gives a review of the various high power laser projects and ignition facilities in the world: the Mercury laser system and Electra (Usa), the krypton fluoride (KrF) laser and the HALNA (high average power laser for nuclear-fusion application) project (Japan), the Shenguang series, the Xingguang facility and the TIL (technical integration line) facility (China), the Vulcan peta-watt interaction facility (UK), the Megajoule project and its feasibility phase: the LIL (laser integration line) facility (France), the Asterix IV/PALS high power laser facility (Czech Republic), and the Phelix project (Germany). In Japan the 100 TW Petawatt Module Laser, constructed in 1997, is being upgraded to the world biggest peta-watt laser. Experiments have been performed with single-pulse large aperture e-beam-pumped Garpun (Russia) and with high-current-density El-1 KrF laser installation (Russia) to investigate Al-Be foil transmittance and stability to multiple e-beam irradiations. An article is dedicated to a comparison of debris shield impacts for 2 experiments at NIF (national ignition facility). (A.C.)

  2. High Power UV LED Industrial Curing Systems

    Energy Technology Data Exchange (ETDEWEB)

    Karlicek, Robert, F., Jr; Sargent, Robert

    2012-05-14

    UV curing is a green technology that is largely underutilized because UV radiation sources like Hg Lamps are unreliable and difficult to use. High Power UV LEDs are now efficient enough to replace Hg Lamps, and offer significantly improved performance relative to Hg Lamps. In this study, a modular, scalable high power UV LED curing system was designed and tested, performing well in industrial coating evaluations. In order to achieve mechanical form factors similar to commercial Hg Lamp systems, a new patent pending design was employed enabling high irradiance at long working distances. While high power UV LEDs are currently only available at longer UVA wavelengths, rapid progress on UVC LEDs and the development of new formulations designed specifically for use with UV LED sources will converge to drive more rapid adoption of UV curing technology. An assessment of the environmental impact of replacing Hg Lamp systems with UV LED systems was performed. Since UV curing is used in only a small portion of the industrial printing, painting and coating markets, the ease of use of UV LED systems should increase the use of UV curing technology. Even a small penetration of the significant number of industrial applications still using oven curing and drying will lead to significant reductions in energy consumption and reductions in the emission of green house gases and solvent emissions.

  3. High speed micromachining with high power UV laser

    Science.gov (United States)

    Patel, Rajesh S.; Bovatsek, James M.

    2013-03-01

    Increasing demand for creating fine features with high accuracy in manufacturing of electronic mobile devices has fueled growth for lasers in manufacturing. High power, high repetition rate ultraviolet (UV) lasers provide an opportunity to implement a cost effective high quality, high throughput micromachining process in a 24/7 manufacturing environment. The energy available per pulse and the pulse repetition frequency (PRF) of diode pumped solid state (DPSS) nanosecond UV lasers have increased steadily over the years. Efficient use of the available energy from a laser is important to generate accurate fine features at a high speed with high quality. To achieve maximum material removal and minimal thermal damage for any laser micromachining application, use of the optimal process parameters including energy density or fluence (J/cm2), pulse width, and repetition rate is important. In this study we present a new high power, high PRF QuasarR 355-40 laser from Spectra-Physics with TimeShiftTM technology for unique software adjustable pulse width, pulse splitting, and pulse shaping capabilities. The benefits of these features for micromachining include improved throughput and quality. Specific example and results of silicon scribing are described to demonstrate the processing benefits of the Quasar's available power, PRF, and TimeShift technology.

  4. New high power linacs and beam physics

    International Nuclear Information System (INIS)

    Wangler, T.P.; Gray, E.R.; Nath, S.; Crandall, K.R.; Hasegawa, K.

    1997-01-01

    New high-power proton linacs must be designed to control beam loss, which can lead to radioactivation of the accelerator. The threat of beam loss is increased significantly by the formation of beam halo. Numerical simulation studies have identified the space-charge interactions, especially those that occur in rms mismatched beams, as a major concern for halo growth. The maximum-amplitude predictions of the simulation codes must be subjected to independent tests to confirm the validity of the results. Consequently, the authors compare predictions from the particle-core halo models with computer simulations to test their understanding of the halo mechanisms that are incorporated in the computer codes. They present and discuss scaling laws that provide guidance for high-power linac design

  5. The high-power iodine laser

    Science.gov (United States)

    Brederlow, G.; Fill, E.; Witte, K. J.

    The book provides a description of the present state of the art concerning the iodine laser, giving particular attention to the design and operation of pulsed high-power iodine lasers. The basic features of the laser are examined, taking into account aspects of spontaneous emission lifetime, hyperfine structure, line broadening and line shifts, stimulated emission cross sections, the influence of magnetic fields, sublevel relaxation, the photodissociation of alkyl iodides, flashlamp technology, excitation in a direct discharge, chemical excitation, and questions regarding the chemical kinetics of the photodissociation iodine laser. The principles of high-power operation are considered along with aspects of beam quality and losses, the design and layout of an iodine laser system, the scalability and prospects of the iodine laser, and the design of the single-beam Asterix III laser.

  6. Industrial Applications of High Power Ultrasonics

    Science.gov (United States)

    Patist, Alex; Bates, Darren

    Since the change of the millennium, high-power ultrasound has become an alternative food processing technology applicable to large-scale commercial applications such as emulsification, homogenization, extraction, crystallization, dewatering, low-temperature pasteurization, degassing, defoaming, activation and inactivation of enzymes, particle size reduction, extrusion, and viscosity alteration. This new focus can be attributed to significant improvements in equipment design and efficiency during the late 1990 s. Like most innovative food processing technologies, high-power ultrasonics is not an off-the-shelf technology, and thus requires careful development and scale-up for each and every application. The objective of this chapter is to present examples of ultrasonic applications that have been successful at the commercialization stage, advantages, and limitations, as well as key learnings from scaling up an innovative food technology in general.

  7. High power, repetitive stacked Blumlein pulse generators

    Energy Technology Data Exchange (ETDEWEB)

    Davanloo, F; Borovina, D L; Korioth, J L; Krause, R K; Collins, C B [Univ. of Texas at Dallas, Richardson, TX (United States). Center for Quantum Electronics; Agee, F J [US Air Force Phillips Lab., Kirtland AFB, NM (United States); Kingsley, L E [US Army CECOM, Ft. Monmouth, NJ (United States)

    1997-12-31

    The repetitive stacked Blumlein pulse power generators developed at the University of Texas at Dallas consist of several triaxial Blumleins stacked in series at one end. The lines are charged in parallel and synchronously commuted with a single switch at the other end. In this way, relatively low charging voltages are multiplied to give a high discharge voltage across an arbitrary load. Extensive characterization of these novel pulsers have been performed over the past few years. Results indicate that they are capable of producing high power waveforms with rise times and repetition rates in the range of 0.5-50 ns and 1-300 Hz, respectively, using a conventional thyratron, spark gap, or photoconductive switch. The progress in the development and use of stacked Blumlein pulse generators is reviewed. The technology and the characteristics of these novel pulsers driving flash x-ray diodes are discussed. (author). 4 figs., 5 refs.

  8. Power Supplies for High Energy Particle Accelerators

    Science.gov (United States)

    Dey, Pranab Kumar

    2016-06-01

    The on-going research and the development projects with Large Hadron Collider at CERN, Geneva, Switzerland has generated enormous enthusiasm and interest amongst all to know about the ultimate findings on `God's Particle'. This paper has made an attempt to unfold the power supply requirements and the methodology adopted to provide the stringent demand of such high energy particle accelerators during the initial stages of the search for the ultimate particles. An attempt has also been made to highlight the present status on the requirement of power supplies in some high energy accelerators with a view that, precautionary measures can be drawn during design and development from earlier experience which will be of help for the proposed third generation synchrotron to be installed in India at a huge cost.

  9. High stability, high current DC-power supplies

    International Nuclear Information System (INIS)

    Hosono, K.; Hatanaka, K.; Itahashi, T.

    1995-01-01

    Improvements of the power supplies and the control system of the AVF cyclotron which is used as an injector to the ring cyclotron and of the transport system to the ring cyclotron were done in order to get more high quality and more stable beam. The power supply of the main coil of the AVF cyclotron was exchanged to new one. The old DCCTs (zero-flux current transformers) used for the power supplies of the trim coils of the AVF cyclotron were changed to new DCCTs to get more stability. The potentiometers used for the reference voltages in the other power supplies of the AVF cyclotron and the transport system were changed to the temperature controlled DAC method for numerical-value settings. This paper presents the results of the improvements. (author)

  10. Low Cost, Low Power, High Sensitivity Magnetometer

    Science.gov (United States)

    2008-12-01

    which are used to measure the small magnetic signals from brain. Other types of vector magnetometers are fluxgate , coil based, and magnetoresistance...concentrator with the magnetometer currently used in Army multimodal sensor systems, the Brown fluxgate . One sees the MEMS fluxgate magnetometer is...Guedes, A.; et al., 2008: Hybrid - LOW COST, LOW POWER, HIGH SENSITIVITY MAGNETOMETER A.S. Edelstein*, James E. Burnette, Greg A. Fischer, M.G

  11. W-band Solid State Power Amplifier for Remote Sensing Radars, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — High power, compact, reliable and affordable power amplifiers operating in the W-band (94 GHz region) are critical to realizing transmitters for many NASA missions...

  12. W-Band Solid State Power Amplifier for Remote Sensing Radars, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — High power, compact, reliable and affordable power amplifiers operating in the W-band (94 GHz region) are critical to realizing transmitters for many NASA missions...

  13. Gate Drive For High Speed, High Power IGBTs

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, M.N.; Cassel, R.L.; de Lamare, J.E.; Pappas, G.C.; /SLAC

    2007-06-18

    A new gate drive for high-voltage, high-power IGBTs has been developed for the SLAC NLC (Next Linear Collider) Solid State Induction Modulator. This paper describes the design and implementation of a driver that allows an IGBT module rated at 800A/3300V to switch up to 3000A at 2200V in 3{micro}S with a rate of current rise of more than 10000A/{micro}S, while still being short circuit protected. Issues regarding fast turn on, high de-saturation voltage detection, and low short circuit peak current will be presented. A novel approach is also used to counter the effect of unequal current sharing between parallel chips inside most high-power IGBT modules. It effectively reduces the collector-emitter peak current, and thus protects the IGBT from being destroyed during soft short circuit conditions at high di/dt.

  14. Gate Drive For High Speed, High Power IGBTs

    International Nuclear Information System (INIS)

    Nguyen, M.N.; Cassel, R.L.; de Lamare, J.E.; Pappas, G.C.; SLAC

    2007-01-01

    A new gate drive for high-voltage, high-power IGBTs has been developed for the SLAC NLC (Next Linear Collider) Solid State Induction Modulator. This paper describes the design and implementation of a driver that allows an IGBT module rated at 800A/3300V to switch up to 3000A at 2200V in 3(micro)S with a rate of current rise of more than 10000A/(micro)S, while still being short circuit protected. Issues regarding fast turn on, high de-saturation voltage detection, and low short circuit peak current will be presented. A novel approach is also used to counter the effect of unequal current sharing between parallel chips inside most high-power IGBT modules. It effectively reduces the collector-emitter peak current, and thus protects the IGBT from being destroyed during soft short circuit conditions at high di/dt

  15. Feasibility studies for a wireless 60 GHz tracking detector readout

    CERN Document Server

    Dittmeier, Sebastian; Soltveit, Hans Kristian; Wiedner, Dirk

    2016-01-01

    The amount of data produced by highly granular silicon tracking detectors in high energy physics experiments poses a major challenge to readout systems. At high collision rates, e.g. at LHC experiments, only a small fraction of data can be read out with currently used technologies. To cope with the requirements of future or upgraded experiments new data transfer techniques are required which offer high data rates at low power and low material budget. Wireless technologies operating in the 60 GHz band or at higher frequencies offer high data rates and are thus a promising upcoming alternative to conventional data transmission via electrical cables or optical fibers. Using wireless technology, the amount of cables and connectors in detectors can be significantly reduced. Tracking detectors profit most from a reduced material budget as fewer secondary particle interactions (multiple Coulomb scattering, energy loss, etc.) improve the tracking performance in general. We present feasibility studies regarding the in...

  16. Gallium Nitride MMICs for mm-Wave Power Operation

    NARCIS (Netherlands)

    Quay, R.; Maroldt, S.; Haupt, C.; Heijningen, M. van; Tessmann, A.

    2009-01-01

    In this paper a Gallium Nitride MMIC technology for high-power amplifiers between 27 GHz and 101 GHz based on 150 nm- and 100 nm-gate technologies is presented. The GaN HEMT MMICs are designed using coplanar waveguide transmission-line-technology on 3-inch semi-insulating SiC substrates. The

  17. High-power planar dielectric waveguide lasers

    International Nuclear Information System (INIS)

    Shepherd, D.P.; Hettrick, S.J.; Li, C.; Mackenzie, J.I.; Beach, R.J.; Mitchell, S.C.; Meissner, H.E.

    2001-01-01

    The advantages and potential hazards of using a planar waveguide as the host in a high-power diode-pumped laser system are described. The techniques discussed include the use of proximity-coupled diodes, double-clad waveguides, unstable resonators, tapers, and integrated passive Q switches. Laser devices are described based on Yb 3+ -, Nd 3+ -, and Tm 3+ -doped YAG, and monolithic and highly compact waveguide lasers with outputs greater than 10 W are demonstrated. The prospects for scaling to the 100 W level and for further integration of devices for added functionality in a monolithic laser system are discussed. (author)

  18. High Energy Density Sciences with High Power Lasers at SACLA

    Science.gov (United States)

    Kodama, Ryosuke

    2013-10-01

    One of the interesting topics on high energy density sciences with high power lasers is creation of extremely high pressures in material. The pressures of more than 0.1 TPa are the energy density corresponding to the chemical bonding energy, resulting in expectation of dramatic changes in the chemical reactions. At pressures of more than TPa, most of material would be melted on the shock Hugoniot curve. However, if the temperature is less than 1eV or lower than a melting point at pressures of more than TPa, novel solid states of matter must be created through a pressured phase transition. One of the interesting materials must be carbon. At pressures of more than TPa, the diamond structure changes to BC and cubic at more than 3TPa. To create such novel states of matter, several kinds of isentropic-like compression techniques are being developed with high power lasers. To explore the ``Tera-Pascal Science,'' now we have a new tool which is an x-ray free electron laser as well as high power lasers. The XFEL will clear the details of the HED states and also efficiently create hot dense matter. We have started a new project on high energy density sciences using an XFEL (SACLA) in Japan, which is a HERMES (High Energy density Revolution of Matter in Extreme States) project.

  19. High-power LEDs for plant cultivation

    Science.gov (United States)

    Tamulaitis, Gintautas; Duchovskis, Pavelas; Bliznikas, Zenius; Breive, Kestutis; Ulinskaite, Raimonda; Brazaityte, Ausra; Novickovas, Algirdas; Zukauskas, Arturas; Shur, Michael S.

    2004-10-01

    We report on high-power solid-state lighting facility for cultivation of greenhouse vegetables and on the results of the study of control of photosynthetic activity and growth morphology of radish and lettuce imposed by variation of the spectral composition of illumination. Experimental lighting modules (useful area of 0.22 m2) were designed based on 4 types of high-power light-emitting diodes (LEDs) with emission peaked in red at the wavelengths of 660 nm and 640 nm (predominantly absorbed by chlorophyll a and b for photosynthesis, respectively), in blue at 455 nm (phototropic function), and in far-red at 735 nm (important for photomorphology). Morphological characteristics, chlorophyll and phytohormone concentrations in radish and lettuce grown in phytotron chambers under lighting with different spectral composition of the LED-based illuminator and under illumination by high pressure sodium lamps with an equivalent photosynthetic photon flux density were compared. A well-balanced solid-state lighting was found to enhance production of green mass and to ensure healthy morphogenesis of plants compared to those grown using conventional lighting. We observed that the plant morphology and concentrations of morphologically active phytohormones is strongly affected by the spectral composition of light in the red region. Commercial application of the LED-based illumination for large-scale plant cultivation is discussed. This technology is favorable from the point of view of energy consumption, controllable growth, and food safety but is hindered by high cost of the LEDs. Large scale manufacturing of high-power red AlInGaP-based LEDs emitting at 650 nm and a further decrease of the photon price for the LEDs emitting in the vicinity of the absorption peak of chlorophylls have to be achieved to promote horticulture applications.

  20. Free-electron masers vs. gyrotrons prospects for high-power sources at millimeter and submillimeter wavelengths

    CERN Document Server

    Thumm, M K

    2002-01-01

    The possible applications of high-power millimeter (mm) and sub-mm waves from free-electron masers (FEMs) and gyro-devices span a wide range of technologies. The plasma physics community has already taken advantage of recent advances in applying high-power mm waves generated by long pulse or continuous wave (CW) gyrotron oscillators and short pulse very high-power FEMs in the areas of RF-plasma production, heating, non-inductive current drive, plasma stabilization and active plasma diagnostics for magnetic confinement thermonuclear fusion research, such as electron cyclotron resonance heating (28-170 GHz), electron cyclotron current drive , collective Thomson scattering , microwave transmission and heat-wave propagation experiments. Continuously frequency tunable FEMs could widen these fields of applications. Another important application of CW gyrotrons is industrial materials processing, e.g. sintering of high-performance functional and structural nanostructured ceramics. Sub-mm wave sources are employed in...

  1. Industrial Applications of High Average Power FELS

    CERN Document Server

    Shinn, Michelle D

    2005-01-01

    The use of lasers for material processing continues to expand, and the annual sales of such lasers exceeds $1 B (US). Large scale (many m2) processing of materials require the economical production of laser powers of the tens of kilowatts, and therefore are not yet commercial processes, although they have been demonstrated. The development of FELs based on superconducting RF (SRF) linac technology provides a scaleable path to laser outputs above 50 kW in the IR, rendering these applications economically viable, since the cost/photon drops as the output power increases. This approach also enables high average power ~ 1 kW output in the UV spectrum. Such FELs will provide quasi-cw (PRFs in the tens of MHz), of ultrafast (pulsewidth ~ 1 ps) output with very high beam quality. This talk will provide an overview of applications tests by our facility's users such as pulsed laser deposition, laser ablation, and laser surface modification, as well as present plans that will be tested with our upgraded FELs. These upg...

  2. Industrial application of high power disk lasers

    Science.gov (United States)

    Brockmann, Rüdiger; Havrilla, David

    2008-02-01

    Laser welding has become one of the fastest growing areas for industrial laser applications. The increasing cost effectiveness of the laser process is enabled by the development of new highly efficient laser sources, such as the Disk laser, coupled with decreasing cost per Watt. TRUMPF introduced the Disk laser several years ago, and today it has become the most reliable laser tool on the market. The excellent beam quality and output powers of up to 10 kW enable its application in the automotive industry as well as in the range of thick plate welding, such as heavy construction and ship building. This serves as an overview of the most recent developments on the TRUMPF Disk laser and its industrial applications like cutting, welding, remote welding and hybrid welding, too. The future prospects regarding increased power and even further improved productivity and economics are presented.

  3. High-field, high-density tokamak power reactor

    International Nuclear Information System (INIS)

    Cohn, D.R.; Cook, D.L.; Hay, R.D.; Kaplan, D.; Kreischer, K.; Lidskii, L.M.; Stephany, W.; Williams, J.E.C.; Jassby, D.L.; Okabayashi, M.

    1977-11-01

    A conceptual design of a compact (R 0 = 6.0 m) high power density (average P/sub f/ = 7.7 MW/m 3 ) tokamak demonstration power reactor has been developed. High magnetic field (B/sub t/ = 7.4 T) and moderate elongation (b/a = 1.6) permit operation at the high density (n(0) approximately 5 x 10 14 cm -3 ) needed for ignition in a relatively small plasma, with a spatially-averaged toroidal beta of only 4%. A unique design for the Nb 3 Sn toroidal-field magnet system reduces the stress in the high-field trunk region, and allows modularization for simpler disassembly. The modest value of toroidal beta permits a simple, modularized plasma-shaping coil system, located inside the TF coil trunk. Heating of the dense central plasma is attained by the use of ripple-assisted injection of 120-keV D 0 beams. The ripple-coil system also affords dynamic control of the plasma temperature during the burn period. A FLIBE-lithium blanket is designed especially for high-power-density operation in a high-field environment, and gives an overall tritium breeding ratio of 1.05 in the slowly pumped lithium

  4. The JLab high power ERL light source

    International Nuclear Information System (INIS)

    Neil, G.R.; Behre, C.; Benson, S.V.

    2006-01-01

    A new THz/IR/UV photon source at Jefferson Lab is the first of a new generation of light sources based on an Energy-Recovered (superconducting) Linac (ERL). The machine has a 160MeV electron beam and an average current of 10mA in 75MHz repetition rate hundred femtosecond bunches. These electron bunches pass through a magnetic chicane and therefore emit synchrotron radiation. For wavelengths longer than the electron bunch the electrons radiate coherently a broadband THz ∼ half cycle pulse whose average brightness is >5 orders of magnitude higher than synchrotron IR sources. Previous measurements showed 20W of average power extracted [Carr, et al., Nature 420 (2002) 153]. The new facility offers simultaneous synchrotron light from the visible through the FIR along with broadband THz production of 100fs pulses with >200W of average power. The FELs also provide record-breaking laser power [Neil, et al., Phys. Rev. Lett. 84 (2000) 662]: up to 10kW of average power in the IR from 1 to 14μm in 400fs pulses at up to 74.85MHz repetition rates and soon will produce similar pulses of 300-1000nm light at up to 3kW of average power from the UV FEL. These ultrashort pulses are ideal for maximizing the interaction with material surfaces. The optical beams are Gaussian with nearly perfect beam quality. See www.jlab.org/FEL for details of the operating characteristics; a wide variety of pulse train configurations are feasible from 10ms long at high repetition rates to continuous operation. The THz and IR system has been commissioned. The UV system is to follow in 2005. The light is transported to user laboratories for basic and applied research. Additional lasers synchronized to the FEL are also available. Past activities have included production of carbon nanotubes, studies of vibrational relaxation of interstitial hydrogen in silicon, pulsed laser deposition and ablation, nitriding of metals, and energy flow in proteins. This paper will present the status of the system and

  5. The JLab high power ERL light source

    Energy Technology Data Exchange (ETDEWEB)

    G.R. Neil; C. Behre; S.V. Benson; M. Bevins; G. Biallas; J. Boyce; J. Coleman; L.A. Dillon-Townes; D. Douglas; H.F. Dylla; R. Evans; A. Grippo; D. Gruber; J. Gubeli; D. Hardy; C. Hernandez-Garcia; K. Jordan; M.J. Kelley; L. Merminga; J. Mammosser; W. Moore; N. Nishimori; E. Pozdeyev; J. Preble; R. Rimmer; Michelle D. Shinn; T. Siggins; C. Tennant; R. Walker; G.P. Williams and S. Zhang

    2005-03-19

    A new THz/IR/UV photon source at Jefferson Lab is the first of a new generation of light sources based on an Energy-Recovered, (superconducting) Linac (ERL). The machine has a 160 MeV electron beam and an average current of 10 mA in 75 MHz repetition rate hundred femtosecond bunches. These electron bunches pass through a magnetic chicane and therefore emit synchrotron radiation. For wavelengths longer than the electron bunch the electrons radiate coherently a broadband THz {approx} half cycle pulse whose average brightness is > 5 orders of magnitude higher than synchrotron IR sources. Previous measurements showed 20 W of average power extracted[1]. The new facility offers simultaneous synchrotron light from the visible through the FIR along with broadband THz production of 100 fs pulses with >200 W of average power. The FELs also provide record-breaking laser power [2]: up to 10 kW of average power in the IR from 1 to 14 microns in 400 fs pulses at up to 74.85 MHz repetition rates and soon will produce similar pulses of 300-1000 nm light at up to 3 kW of average power from the UV FEL. These ultrashort pulses are ideal for maximizing the interaction with material surfaces. The optical beams are Gaussian with nearly perfect beam quality. See www.jlab.org/FEL for details of the operating characteristics; a wide variety of pulse train configurations are feasible from 10 microseconds long at high repetition rates to continuous operation. The THz and IR system has been commissioned. The UV system is to follow in 2005. The light is transported to user laboratories for basic and applied research. Additional lasers synchronized to the FEL are also available. Past activities have included production of carbon nanotubes, studies of vibrational relaxation of interstitial hydrogen in silicon, pulsed laser deposition and ablation, nitriding of metals, and energy flow in proteins. This paper will present the status of the system and discuss some of the discoveries we have made

  6. A power scalable PLL frequency synthesizer for high-speed Δ—Σ ADC

    International Nuclear Information System (INIS)

    Han Siyang; Chi Baoyong; Zhang Xinwang; Wang Zhihua

    2014-01-01

    A 35–130 MHz/300–360 MHz phase-locked loop frequency synthesizer for Δ—Σ analog-to-digital converter (ADC) in 65 nm CMOS is presented. The frequency synthesizer can work in low phase-noise mode (300–360 MHz) or in low-power mode (35–130 MHz) to satisfy the ADC's requirements. To switch between these two modes, a high frequency GHz LC VCO followed by a divided-by-four frequency divider and a low frequency ring VCO followed by a divided-by-two frequency divider are integrated on-chip. The measured results show that the frequency synthesizer achieves a phase-noise of −132 dBc/Hz at 1 MHz offset and an integrated RMS jitter of 1.12 ps with 1.74 mW power consumption from a 1.2 V power supply in low phase-noise mode. In low-power mode, the frequency synthesizer achieves a phase-noise of −112 dBc/Hz at 1 MHz offset and an integrated RMS jitter of 7.23 ps with 0.92 mW power consumption from a 1.2 V power supply. (semiconductor integrated circuits)

  7. Magnetic films for GHz applications (abstract)

    International Nuclear Information System (INIS)

    Korenivski, V.; van Dover, R.B.

    1997-01-01

    Tremendous growth of the communications industry and the increasingly high demand for low-cost light-weight/small-size products drive technology to designs with a high degree of integration. In particular, planar inductors used in integrated circuits with significantly improved inductance per unit area characteristics are needed for further miniaturization of cellular phones operating at 0.95 and 1.9 GHz. Little has been done, however, to use magnetic films to improve the performance and/or reduce size of planar magnetic flux devices. The successful thin-film material would have a high ferromagnetic resonance (FMR) frequency (well above the operating frequency of the device), large permaeability, and low magnetic loss, and very importantly be technologically attractive, i.e., be process compatible with IC technology and have as few preparation steps as possible. Here, we report on fabrication of metallic ferromagnetic films of CoNbZr, CoNbZr/AlN mulitilayered laminates, and exchange-biased structures suitable for GHz applications. Lamination of CoNbZr with thin insulating layers of AlN is shown to significantly improve the microstructure and dc magnetic properties of the films having thicknesses >0.2 μm, as well as to be effective in suppressing eddy current losses at frequencies up to 1 endash 2 GHz. We use exchange biasing to increase the FMR frequency of soft CoNbZr. In-plane unidirectional anisotropy fields of ∼50 Oe are achieved, which result in FMR frequencies >2 GHz. Permeability values of ∼200 with quality factors of ∼10 at 1 GHz are demonstrated. The films are deposited at room temperature and require no postdeposition processing. Application of these films in planar inductors is discussed.copyright 1997 American Institute of Physics

  8. Feasibility studies for a wireless 60 GHz tracking detector readout

    International Nuclear Information System (INIS)

    Dittmeier, S.; Schöning, A.; Soltveit, H.K.; Wiedner, D.

    2016-01-01

    The amount of data produced by highly granular silicon tracking detectors in high energy physics experiments poses a major challenge to readout systems. At high collision rates, e.g. at LHC experiments, only a small fraction of data can be read out with currently used technologies. To cope with the requirements of future or upgraded experiments new data transfer techniques are required which offer high data rates at low power and low material budget. Wireless technologies operating in the 60 GHz band or at higher frequencies offer high data rates and are thus a promising upcoming alternative to conventional data transmission via electrical cables or optical fibers. Using wireless technology, the amount of cables and connectors in detectors can be significantly reduced. Tracking detectors profit most from a reduced material budget as fewer secondary particle interactions (multiple Coulomb scattering, energy loss, etc.) improve the tracking performance in general. We present feasibility studies regarding the integration of the wireless technology at 60 GHz into a silicon tracking detector. We use spare silicon strip modules of the ATLAS experiment as test samples which are measured to be opaque in the 60 GHz range. The reduction of cross talk between links and the attenuation of reflections is studied. An estimate of the maximum achievable link density is given. It is shown that wireless links can be placed as close as 2 cm next to each other for a layer distance of 10 cm by exploiting one or several of the following measures: highly directive antennas, absorbers like graphite foam, linear polarization and frequency channeling. Combining these measures, a data rate area density of up to 11 Tb/(s·m"2) seems feasible. In addition, two types of silicon sensors are tested under mm-wave irradiation in order to determine the influence of 60 GHz data transmission on the detector performance: an ATLAS silicon strip sensor module and an HV-MAPS prototype for the Mu3e

  9. Feasibility studies for a wireless 60 GHz tracking detector readout

    Energy Technology Data Exchange (ETDEWEB)

    Dittmeier, S., E-mail: dittmeier@physi.uni-heidelberg.de; Schöning, A.; Soltveit, H.K.; Wiedner, D.

    2016-09-11

    The amount of data produced by highly granular silicon tracking detectors in high energy physics experiments poses a major challenge to readout systems. At high collision rates, e.g. at LHC experiments, only a small fraction of data can be read out with currently used technologies. To cope with the requirements of future or upgraded experiments new data transfer techniques are required which offer high data rates at low power and low material budget. Wireless technologies operating in the 60 GHz band or at higher frequencies offer high data rates and are thus a promising upcoming alternative to conventional data transmission via electrical cables or optical fibers. Using wireless technology, the amount of cables and connectors in detectors can be significantly reduced. Tracking detectors profit most from a reduced material budget as fewer secondary particle interactions (multiple Coulomb scattering, energy loss, etc.) improve the tracking performance in general. We present feasibility studies regarding the integration of the wireless technology at 60 GHz into a silicon tracking detector. We use spare silicon strip modules of the ATLAS experiment as test samples which are measured to be opaque in the 60 GHz range. The reduction of cross talk between links and the attenuation of reflections is studied. An estimate of the maximum achievable link density is given. It is shown that wireless links can be placed as close as 2 cm next to each other for a layer distance of 10 cm by exploiting one or several of the following measures: highly directive antennas, absorbers like graphite foam, linear polarization and frequency channeling. Combining these measures, a data rate area density of up to 11 Tb/(s·m{sup 2}) seems feasible. In addition, two types of silicon sensors are tested under mm-wave irradiation in order to determine the influence of 60 GHz data transmission on the detector performance: an ATLAS silicon strip sensor module and an HV-MAPS prototype for the Mu3e

  10. Millimeter-Wave Receiver Concepts for 77 GHz Automotive Radar in Silicon-Germanium Technology

    CERN Document Server

    Kissinger, Dietmar

    2012-01-01

    The book presents the analysis and design of integrated automotive radar receivers in Silicon-Germanium technology, for use in complex multi-channel radar transceiver front-ends in the 77GHz frequency band. The main emphasis of the work is the realization of high-linearity and low-power modular receiver channels as well as the investigation of millimeter-wave integrated test concepts for the receiver front-end.

  11. A high-power two stage traveling-wave tube amplifier

    International Nuclear Information System (INIS)

    Shiffler, D.; Nation, J.A.; Schachter, L.; Ivers, J.D.; Kerslick, G.S.

    1991-01-01

    Results are presented on the development of a two stage high-efficiency, high-power 8.76-GHz traveling-wave tube amplifier. The work presented augments previously reported data on a single stage amplifier and presents new data on the operational characteristics of two identical amplifiers operated in series and separated from each other by a sever. Peak powers of 410 MW have been obtained over the complete pulse duration of the device, with a conversion efficiency from the electron beam to microwave energy of 45%. In all operating conditions the severed amplifier showed a ''sideband''-like structure in the frequency spectrum of the microwave radiation. A similar structure was apparent at output powers in excess of 70 MW in the single stage device. The frequencies of the ''sidebands'' are not symmetric with respect to the center frequency. The maximum, single frequency, average output power was 210 MW corresponding to an amplifier efficiency of 24%. Simulation data is also presented that indicates that the short amplifiers used in this work exhibit significant differences in behavior from conventional low-power amplifiers. These include finite length effects on the gain characteristics, which may account for the observed narrow bandwidth of the amplifiers and for the appearance of the sidebands. It is also found that the bunching length for the beam may be a significant fraction of the total amplifier length

  12. Third harmonic generation of high power far infrared radiation in semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Urban, M [Ecole Polytechnique Federale, Lausanne (Switzerland). Centre de Recherche en Physique des Plasma (CRPP)

    1996-04-01

    We investigated the third harmonic generation of high power infrared radiation in doped semiconductors with emphasis on the conversion efficiency. The third harmonic generation effect is based on the nonlinear response of the conduction band electrons in the semiconductor with respect to the electric field of the incident electromagnetic wave. Because this work is directed towards a proposed application in fusion plasma diagnostics, the experimental requirements for the radiation source at the fundamental frequency are roughly given as follows: a wavelength of the radiation at the fundamental frequency in the order of 1 mm and an incident power greater than 1 MW. The most important experiments of this work were performed using the high power far infrared laser of the CRPP. With this laser a new laser line was discovered, which fits exactly the source specifications given above: the wavelength is 676 {mu}m and the maximum power is up to 2 MW. Additional experiments were carried out using a 496 {mu}m laser and a 140 GHz (2.1 mm) gyrotron. The main experimental progress with respect to previous work in this field is, in addition to the use of a very high power laser, the possibility of an absolute calibration of the detectors for the far infrared radiation and the availability of a new type of detector with a very fast response. This detector made it possible to measure the power at the fundamental as well as the third harmonic frequency with full temporal resolution of the fluctuations during the laser pulse. Therefore the power dependence of the third harmonic generation efficiency could be measured directly. The materials investigated were InSb as an example of a narrow gap semiconductor and Si as standard material. The main results are: narrow gap semiconductors indeed have a highly nonlinear electronic response, but the narrow band gap leads at the same time to a low power threshold for internal breakdown, which is due to impact ionization. figs., tabs., refs.

  13. A high speed low power low offset dynamic comparator used in SHA-less pipelined ADC

    Science.gov (United States)

    Shubin, Liu; Zhangming, Zhu; Yintang, Yang; Lianxi, Liu

    2014-05-01

    A novel fully differential high speed high resolution low offset CMOS dynamic comparator has been implemented in the SMIC 0.18 μm process used for a sample-and-hold amplifier (SHA)-less pipelined analog-to-digital converters (ADC). Based on the analysis and optimization between delay time and offset, an enhanced reset architecture with transmission gate was introduced to speed up the comparison and reset procedure. Four inputs with two cross coupled differential pairs, reconstituted bias circuit for tail current transistor and common centroid layouts make the comparator more robust against mismatch and process variations. The simulation results demonstrate that the proposed design achieves 1 mV sensitivity at 2.2 GHz sampling rate with a power consumption of 510 μW, while the mean offset voltage is equal to 10.244 mV.

  14. Study of paramagnetic defect centers in as-grown and annealed TiO2 anatase and rutile nanoparticles by a variable-temperature X-band and high-frequency (236 GHz) EPR.

    Science.gov (United States)

    Misra, S K; Andronenko, S I; Tipikin, D; Freed, J H; Somani, V; Prakash, Om

    2016-03-01

    Detailed EPR investigations on as-grown and annealed TiO 2 nanoparticles in the anatase and rutile phases were carried out at X-band (9.6 GHz) at 77, 120-300 K and at 236 GHz at 292 K. The analysis of EPR data for as-grown and annealed anatase and rutile samples revealed the presence of several paramagnetic centers: Ti 3+ , O - , adsorbed oxygen (O 2 - ) and oxygen vacancies. On the other hand, in as-grown rutile samples, there were observed EPR lines due to adsorbed oxygen (O 2 - ) and the Fe 3+ ions in both Ti 4+ substitutional positions, with and without coupling to an oxygen vacancy in the near neighborhood. Anatase nanoparticles were completely converted to rutile phase when annealed at 1000° C, exhibiting EPR spectra similar to those exhibited by the as-grown rutile nanoparticles. The high-frequency (236 GHz) EPR data on anatase and rutile samples, recorded in the region about g = 2.0 exhibit resolved EPR lines, due to O - and O 2 - ions enabling determination of their g-values with higher precision, as well as observation of hyperfine sextets due to Mn 2+ and Mn 4+ ions in anatase.

  15. Performance of 3.9 GHz SRF cavities at Fermilab's ILCTA_MDB nhorizontal test stand

    Energy Technology Data Exchange (ETDEWEB)

    Harms, Elvin; Hocker, Andy; /Fermilab

    2008-08-01

    Fermilab is building a cryomodule containing four 3.9 GHz superconducting radio frequency (SRF) cavities for the Free electron LASer in Hamburg (FLASH) facility at the Deutsches Elektronen-SYnchrotron (DESY) laboratory. Before assembling the cavities into the cryomodule, each individual cavity is tested at Fermilab's Horizontal Test Stand (HTS). The HTS provides the capability to test fully-dressed SRF cavities at 1.8 K with high-power pulsed RF in order to verify that the cavities achieve performance requirements under these conditions. The performance at the HTS of the 3.9 GHz cavities built for FLASH is presented here.

  16. Application of high power microwave vacuum electron devices

    International Nuclear Information System (INIS)

    Ding Yaogen; Liu Pukun; Zhang Zhaochuan; Wang Yong; Shen Bin

    2011-01-01

    High power microwave vacuum electron devices can work at high frequency, high peak and average power. They have been widely used in military and civil microwave electron systems, such as radar, communication,countermeasure, TV broadcast, particle accelerators, plasma heating devices of fusion, microwave sensing and microwave heating. In scientific research, high power microwave vacuum electron devices are used mainly on high energy particle accelerator and fusion research. The devices include high peak power klystron, CW and long pulse high power klystron, multi-beam klystron,and high power gyrotron. In national economy, high power microwave vacuum electron devices are used mainly on weather and navigation radar, medical and radiation accelerator, TV broadcast and communication system. The devices include high power pulse and CW klystron, extended interaction klystron, traveling wave tube (TWT), magnetron and induced output tube (IOT). The state of art, common technology problems and trends of high power microwave vacuum electron devices are introduced in this paper. (authors)

  17. First 200 kW CW operation of a 60 GHz gyrotron

    International Nuclear Information System (INIS)

    Jory, H.; Bier, R.; Evans, S.; Felch, K.; Fox, L.; Huey, H.; Shively, J.; Spang, S.

    1983-01-01

    The gyrotron is a microwave tube which employs the electron cyclotron maser interaction to produce high power output at millimeter wavelengths. It has important and growing applications for heating of plasmas in controlled thermonuclear fusion experiments. The Varian 60 GHz gyrotron has recently generated microwave power in excess of 200 kW during CW operation, wth excellent dynamic range and operating stability. This is the highest average power ever produced by a microwave tube in the millimeter wave region. A description of the gyrotron design and test results are presented

  18. Initial tests of an 11.4 GHz magnicon amplifier

    International Nuclear Information System (INIS)

    Gold, S.H.; Sullivan, C.A.; Manheimer, W.M.; Hafizi, B.

    1994-01-01

    The magnicon, a scanning beam microwave amplifier related to the gyrocon, is a possible replacement for klystron amplifiers in future high-gradient linear accelerators. The magnicon circuit consists of a multicavity deflection system followed by an output cavity. The purpose of the deflection system is to spin up the electron beam phase-coherently to high transverse momentum. In order to do this, the deflection cavities employ rotating TM 11 modes, producing a gyrating electron beam whose centroid rotates about the cavity axis in synchronism with the advance in phase of the rf modes. The output cavity employs a cyclotron resonant mechanism to extract principally the transverse beam momentum. It employs an rf mode that rotates synchronously with the deflection cavity modes, and with the entry point of the electron beam into the output cavity, making possible a highly efficient interaction. The NRL magnicon uses a 100--200 A, 500 keV beam produced by a cold-cathode diode on the NRL Long-Pulse Accelerator Facility. The first cavity is externally driven at 5.7 GHz, while the output cavity is designed to produce megawatts of power at 11.4 GHz in the TM 210 mode. In this paper, the authors present a progress report on the NRL magnicon experiment. They will discuss the procedure used to cold test and calibrate the magnicon circuit, and present initial results from experimental operations

  19. High-power converters and AC drives

    CERN Document Server

    Wu, Bin

    2017-01-01

    This new edition reflects the recent technological advancements in the MV drive industry, such as advanced multilevel converters and drive configurations. It includes three new chapters, Control of Synchronous Motor Drives, Transformerless MV Drives, and Matrix Converter Fed Drives. In addition, there are extensively revised chapters on Multilevel Voltage Source Inverters and Voltage Source Inverter-Fed Drives. This book includes a systematic analysis on a variety of high-power multilevel converters, illustrates important concepts with simulations and experiments, introduces various megawatt drives produced by world leading drive manufacturers, and addresses practical problems and their mitigations methods.

  20. Compulsator, a high power compensated pulsed alternator

    International Nuclear Information System (INIS)

    Weldon, W.F.; Bird, W.L.; Driga, M.D.; Rylander, H.G.; Tolk, K.M.; Woodson, H.H.

    1983-01-01

    This chapter describes a pulsed power supply utilizing inertial energy storage as a possible replacement for large capacitor banks. The compulsator overcomes many of the limitations of the pulsed homopolar generators previously developed by the Center for Electromechanics and elsewhere in that it offers high voltage (10's of kV) and consequently higher pulse rise times, is self commutating, and offers the possibility of generating repetitive pulses. The compulsator converts rotational inertial energy directly into electrical energy utilizing the principles of both magnetic induction and flux compression. The theory of operation, a prototype compulsator design, and advanced compulsator designs are discussed

  1. Cost optimisation studies of high power accelerators

    Energy Technology Data Exchange (ETDEWEB)

    McAdams, R.; Nightingale, M.P.S.; Godden, D. [AEA Technology, Oxon (United Kingdom)] [and others

    1995-10-01

    Cost optimisation studies are carried out for an accelerator based neutron source consisting of a series of linear accelerators. The characteristics of the lowest cost design for a given beam current and energy machine such as power and length are found to depend on the lifetime envisaged for it. For a fixed neutron yield it is preferable to have a low current, high energy machine. The benefits of superconducting technology are also investigated. A Separated Orbit Cyclotron (SOC) has the potential to reduce capital and operating costs and intial estimates for the transverse and longitudinal current limits of such machines are made.

  2. Design of a high power cross field amplifier at X band with an internally coupled waveguide

    International Nuclear Information System (INIS)

    Eppley, K.; Ko, Kwok.

    1991-01-01

    Cross field amplifiers (CFA) have been used in many applications where high power, high frequency microwaves are needed. Although these tubes have been manufactured for decades, theoretical analysis of their properties is not as highly developed as for other microwave devices such as klystrons. We have developed a simulation model for CFAs using the PIC code CONDOR. Our simulations indicate that there are limits to the maximum RF field strength that a CEA can sustain. When the fields become too high, efficiency becomes very poor, and the currents drawn may become so large that secondary emission cannot be maintained. It is therefore desirable to reduce the circuit impedance of a very high power tube. One method for doing this, proposed by Feinstein, involves periodically coupling a standard CFA circuit to an internal waveguide. Most of the power flows in the waveguide, so the overall impedance is much reduced. By adjusting the guide dimensions one can vary the impedance. Thus one can retain high impedance at the low power end but low impedance at the high power end. In principle one can maintain constant RF voltage throughout the tube. CONDOR simulations have identified a good operating point at X band, with power generation of over 5 MW per cm and total efficiency of over 60 percent. ARGUS simulations have modelled the cold test properties of the coupled structure. The nominal design specifications are 300 MW output, 17 db gain, frequency 11.4 GHz, dc voltage 142 kV, magnetic field 5 kG, anode cathode gap 3.6 mm, total interaction length about 60 cm. We will discuss the results of code simulations and report on the status of the experimental effort

  3. Planck intermediate results. XXX. The angular power spectrum of polarized dust emission at intermediate and high Galactic latitudes

    Science.gov (United States)

    Planck Collaboration; Adam, R.; Ade, P. A. R.; Aghanim, N.; Arnaud, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartlett, J. G.; Bartolo, N.; Battaner, E.; Benabed, K.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Bracco, A.; Bucher, M.; Burigana, C.; Butler, R. C.; Calabrese, E.; Cardoso, J.-F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chary, R.-R.; Chiang, H. C.; Christensen, P. R.; Clements, D. L.; Colombi, S.; Colombo, L. P. L.; Combet, C.; Couchot, F.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Zotti, G.; Delabrouille, J.; Delouis, J.-M.; Désert, F.-X.; Dickinson, C.; Diego, J. M.; Dolag, K.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dunkley, J.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Falgarone, E.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Ghosh, T.; Giard, M.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Guillet, V.; Hansen, F. K.; Hanson, D.; Harrison, D. L.; Helou, G.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hivon, E.; Hobson, M.; Holmes, W. A.; Huffenberger, K. M.; Hurier, G.; Jaffe, A. H.; Jaffe, T. R.; Jewell, J.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Knox, L.; Krachmalnicoff, N.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Leahy, J. P.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maffei, B.; Maino, D.; Mandolesi, N.; Mangilli, A.; Maris, M.; Martin, P. G.; Martínez-González, E.; Masi, S.; Matarrese, S.; Mazzotta, P.; Meinhold, P. R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; Pagano, L.; Pajot, F.; Paladini, R.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Pearson, T. J.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Pratt, G. W.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reach, W. T.; Rebolo, R.; Remazeilles, M.; Renault, C.; Renzi, A.; Ricciardi, S.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rossetti, M.; Roudier, G.; Rouillé d'Orfeuil, B.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Scott, D.; Soler, J. D.; Spencer, L. D.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vibert, L.; Vielva, P.; Villa, F.; Wade, L. A.; Wandelt, B. D.; Watson, R.; Wehus, I. K.; White, M.; White, S. D. M.; Yvon, D.; Zacchei, A.; Zonca, A.

    2016-02-01

    The polarized thermal emission from diffuse Galactic dust is the main foreground present in measurements of the polarization of the cosmic microwave background (CMB) at frequencies above 100 GHz. In this paper we exploit the uniqueness of the Planck HFI polarization data from 100 to 353 GHz to measure the polarized dust angular power spectra CℓEE and CℓBB over the multipole range 40 <ℓ< 600 well away from the Galactic plane. These measurements will bring new insights into interstellar dust physics and allow a precise determination of the level of contamination for CMB polarization experiments. Despite the non-Gaussian and anisotropic nature of Galactic dust, we show that general statistical properties of the emission can be characterized accurately over large fractions of the sky using angular power spectra. The polarization power spectra of the dust are well described by power laws in multipole, Cℓ ∝ ℓα, with exponents αEE,BB = -2.42 ± 0.02. The amplitudes of the polarization power spectra vary with the average brightness in a way similar to the intensity power spectra. The frequency dependence of the dust polarization spectra is consistent with modified blackbody emission with βd = 1.59 and Td = 19.6 K down to the lowest Planck HFI frequencies. We find a systematic difference between the amplitudes of the Galactic B- and E-modes, CℓBB/CℓEE = 0.5. We verify that these general properties are preserved towards high Galactic latitudes with low dust column densities. We show that even in the faintest dust-emitting regions there are no "clean" windows in the sky where primordial CMB B-mode polarization measurements could be made without subtraction of foreground emission. Finally, we investigate the level of dust polarization in the specific field recently targeted by the BICEP2 experiment. Extrapolation of the Planck 353 GHz data to 150 GHz gives a dust power 𝒟ℓBB ≡ ℓ(ℓ+1)CℓBB/(2π) of 1.32 × 10-2 μKCMB2 over the multipole range

  4. Electromagnetic and thermal analysis of distributed cooled high power millimeter wave windows

    International Nuclear Information System (INIS)

    Nelson, S.D.; Reitter, T.; Caplan, M.; Moeller, C.

    1996-01-01

    The sectional high-frequency internally-cooled window, as proposed by General Atomics(1), has unique potential for allowing microwave sources to reach multi-megawatt CW levels with application to ECRH. Designs are being investigated using computational electromagnetic (EM), thermal, and mechanical codes at 110 GHz and 170 GHz to examine the design tradeoffs between RF performance and thermal mechanical safety margins. The EM analyses are for the window, under vacuum at one MW and includes variations in the shapes of the cooling fins, the surface treatment of the window elements themselves, the cooling fin tip treatment, the window pitch angle, and the waveguide effects. One advantage of the distributed cooled window is it close-quote s extensibility to higher power levels. Results in the modeling efforts are presented showing the EM field concentrations (which then will feed into the thermal analysis), the energy scattering/reflection, the transmitted launch angle variation as a function of physical geometry, and the spatial energy distribution and loss as a function of time and position. copyright 1996 American Institute of Physics

  5. TWT design requirements for 30/20 GHz digital communications' satellite

    Science.gov (United States)

    Stankiewicz, N.; Anzic, G.

    1979-01-01

    The rapid growth of communication traffic (voice, data, and video) requires the development of additional frequency bands before the 1990's. The frequencies currently in use for satellite communications at 6/4 GHz are crowded and demands for 14/12 GHz systems are increasing. Projections are that these bands will be filled to capacity by the late 1980's. The next higher frequency band allocated for satellite communications is at 30/20 GHz. For interrelated reasons of efficiency, power level, and system reliability criteria, a candidate for the downlink amplifier in a 30/20 GHz communications' satellite is a dual mode traveling wave tube (TWT) equipped with a highly efficient depressed collector. A summary is given of the analyses which determine the TWT design requirements. The overall efficiency of such a tube is then inferred from a parametric study and from experimental data on multistaged depressed collectors. The expected TWT efficiency at 4 dB below output saturation is 24 percent in the high mode and 22 percent in the low mode.

  6. Analysis of a prototype of a novel 1.5 MW, 170 GHz coaxial cavity gyrotron

    International Nuclear Information System (INIS)

    Rzesnicki, T.

    2007-06-01

    A 170 GHz, 2 MW coaxial cavity gyrotron is under development at the Institut fuer Hochleistungsimpuls- und Mikrowellentechnik (IHM) at Forschungszentrum Karlsruhe (FZK) which will be used as a high power microwave source for heating, current drive and stability control of plasmas in the International Thermonuclear Experimental Reactor (ITER). At frequencies above about 100 GHz the output power of conventional gyrotrons with cylindrical hollow waveguide cavities is limited to 1 MW in CW operation mainly due to the high Ohmic losses and the space charge voltage depression of the electron beam. The coaxial geometry enables a reduction of the mode competition in the gyrotron resonator and decreases also the influence of the beam voltage depression. As result a very high order operating mode (for example TE34,19 at 170 GHz) can be chosen which ultimately allows to increase the output power of the gyrotron in CW operation to a value as high as 2 MW. A first prototype of the 170 GHz, 2 MW coaxial cavity gyrotron has been designed, built and experimentally tested in short pulse operation at FZK. The main goal of this work was to investigate experimentally the design of the critical gyrotron components such as electron gun, resonator and a quasi-optical RF system. Those components are same as used in the first industrial coaxial prototype gyrotron for ITER. During the experiments a strong instability was observed inside the gyrotron tube due to the excitation of parasitic low frequency oscillations. The mechanism of the oscillations has been studied and possibilities for their suppression of these oscillations are proposed and experimentally verified. The RF output system is one of the most critical components. It is responsible for the coupling of the gyrotron power out of the gyrotron by converting the microwave power generated in the TE 34,19 -mode into a fundamental free space TEM 0,0 ''Gaussian'' mode. The performance of the RF output system has been tested in low

  7. Development of High Power Vacuum Tubes for Accelerators and Plasma Heating

    Science.gov (United States)

    Srivastava, Vishnu

    2012-11-01

    High pulsed power magnetrons and klystrons for medical and industrial accelerators, and high CW power klystrons and gyrotrons for plasma heating in tokamak, are being developed at CEERI. S-band 2.0MW pulsed tunable magnetrons of centre frequency 2856MHz and 2998 MHz were developed, and S-band 2.6MW pulsed tunable magnetron is being developed for medical LINAC, and 3MW pulsed tunable magnetron is being developed for industrial accelerator. S-band (2856MHz), 5MW pulsed klystron was developed for particle accelerator, and S-band 6MW pulsed klystron is under development for 10MeV industrial accelerator. 350MHz, 100kW (CW) klystron is being developed for proton accelerator, and C-band 250kW (CW) klystron is being developed for plasma heating. 42GHz, 200kW (CW/Long pulse) gyrotron is under development for plasma heating. Plasma filled tubes are also being developed for switching. 25kV/1kA and 40kV/3kA thyratrons were developed for high voltage high current switching in pulse modulators for magnetrons and klystrons. 25kV/3kA Pseudospark switch of current rise time of 1kA/|a-sec and pulse repetition rate of 500Hz is being developed. Plasma assisted high power microwave device is also being investigated.

  8. Development of High Power Vacuum Tubes for Accelerators and Plasma Heating

    International Nuclear Information System (INIS)

    Srivastava, Vishnu

    2012-01-01

    High pulsed power magnetrons and klystrons for medical and industrial accelerators, and high CW power klystrons and gyrotrons for plasma heating in tokamak, are being developed at CEERI. S-band 2.0MW pulsed tunable magnetrons of centre frequency 2856MHz and 2998 MHz were developed, and S-band 2.6MW pulsed tunable magnetron is being developed for medical LINAC, and 3MW pulsed tunable magnetron is being developed for industrial accelerator. S-band (2856MHz), 5MW pulsed klystron was developed for particle accelerator, and S-band 6MW pulsed klystron is under development for 10MeV industrial accelerator. 350MHz, 100kW (CW) klystron is being developed for proton accelerator, and C-band 250kW (CW) klystron is being developed for plasma heating. 42GHz, 200kW (CW/Long pulse) gyrotron is under development for plasma heating. Plasma filled tubes are also being developed for switching. 25kV/1kA and 40kV/3kA thyratrons were developed for high voltage high current switching in pulse modulators for magnetrons and klystrons. 25kV/3kA Pseudospark switch of current rise time of 1kA/|a-sec and pulse repetition rate of 500Hz is being developed. Plasma assisted high power microwave device is also being investigated.

  9. Low jitter and high power all-active mode-locked lasers

    DEFF Research Database (Denmark)

    Yvind, Kresten; Larsson, David; Christiansen, Lotte Jin

    2003-01-01

    A novel epitaxial design leading to low loss and low gain saturation improves the properties of 40 GHz mode-locked lasers. We obtain 2.8 ps nearly chirp free pulses with 228 fs jitter and fiber-coupled power of 7 mW.......A novel epitaxial design leading to low loss and low gain saturation improves the properties of 40 GHz mode-locked lasers. We obtain 2.8 ps nearly chirp free pulses with 228 fs jitter and fiber-coupled power of 7 mW....

  10. High-Power Ion Thruster Technology

    Science.gov (United States)

    Beattie, J. R.; Matossian, J. N.

    1996-01-01

    Performance data are presented for the NASA/Hughes 30-cm-diam 'common' thruster operated over the power range from 600 W to 4.6 kW. At the 4.6-kW power level, the thruster produces 172 mN of thrust at a specific impulse of just under 4000 s. Xenon pressure and temperature measurements are presented for a 6.4-mm-diam hollow cathode operated at emission currents ranging from 5 to 30 A and flow rates of 4 sccm and 8 sccm. Highly reproducible results show that the cathode temperature is a linear function of emission current, ranging from approx. 1000 C to 1150 C over this same current range. Laser-induced fluorescence (LIF) measurements obtained from a 30-cm-diam thruster are presented, suggesting that LIF could be a valuable diagnostic for real-time assessment of accelerator-arid erosion. Calibration results of laminar-thin-film (LTF) erosion badges with bulk molybdenum are presented for 300-eV xenon, krypton, and argon sputtering ions. Facility-pressure effects on the charge-exchange ion current collected by 8-cm-diam and 30-cm-diam thrusters operated on xenon propellant are presented to show that accel current is nearly independent of facility pressure at low pressures, but increases rapidly under high-background-pressure conditions.

  11. A high power cross-field amplifier at X-Band

    International Nuclear Information System (INIS)

    Eppley, K.; Feinstein, J.; Ko, K.; Kroll, N.; Lee, T.; Nelson, E.

    1991-05-01

    A high power cross-field amplifier is under development at SLAC with the objective of providing sufficient peak power to feed a section of an X-Band (11.424 GHz) accelerator without the need for pulse compression. The CFA being designed employs a conventional distributed secondary emission cathode but a novel anode structure which consists of an array of vane resonators alternatively coupled to a rectangular waveguide. The waveguide impedance (width) is tapered linearly from input to output so as to provide a constant RF voltage at the vane tips, leading to uniform power generation along the structure. Nominal design for this tube calls for 300 MW output power, 20 dB gain, DC voltage 142 KV, magnetic field 5 KG, anode-cathode gap 3.6 mm and total interaction length of about 60 cm. These specifications have been supported by computer simulations of both the RF slow wave structure as well as the electron space charge wave interaction. We have used ARGUS to model the cold circuit properties and CONDOR to model the electronic power conversion. An efficiency of 60 percent can be expected. We will discuss the details of the design effort. 5 refs., 6 figs

  12. 14 CFR 101.25 - Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets.

    Science.gov (United States)

    2010-01-01

    ... Power Rockets and Class 3-Advanced High Power Rockets. 101.25 Section 101.25 Aeronautics and Space... OPERATING RULES MOORED BALLOONS, KITES, AMATEUR ROCKETS AND UNMANNED FREE BALLOONS Amateur Rockets § 101.25 Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets. When operating...

  13. Fault analysis and strategy of high pulsed power supply for high power laser

    International Nuclear Information System (INIS)

    Liu Kefu; Qin Shihong; Li Jin; Pan Yuan; Yao Zonggan; Zheng Wanguo; Guo Liangfu; Zhou Peizhang; Li Yizheng; Chen Dehuai

    2001-01-01

    according to the requirements of driving flash-lamp, a high pulsed power supply (PPS) based on capacitors as energy storage elements is designed. The author analyzes in detail the faults of high pulsed power supply for high power laser. Such as capacitor internal short-circuit, main bus breakdown to ground, flashlamp sudden short or break. The fault current and voltage waveforms were given by circuit simulations. Based on the analysis and computation, the protection strategy with the fast fuse and ZnO was put forward, which can reduce the damage of PPS to the lower extent and provide the personnel safe and collateral property from the all threats. The preliminary experiments demonstrated that the design of the PPS can satisfy the project requirements

  14. Optimal Operation of Plug-In Electric Vehicles in Power Systems with High Wind Power Penetrations

    DEFF Research Database (Denmark)

    Hu, Weihao; Su, Chi; Chen, Zhe

    2013-01-01

    in the power systems with high wind power penetrations. In this paper, the integration of plug-in electric vehicles in the power systems with high wind power penetrations is proposed and discussed. Optimal operation strategies of PEV in the spot market are proposed in order to decrease the energy cost for PEV......The Danish power system has a large penetration of wind power. The wind fluctuation causes a high variation in the power generation, which must be balanced by other sources. The battery storage based Plug-In Electric Vehicles (PEV) may be a possible solution to balance the wind power variations...... owners. Furthermore, the application of battery storage based aggregated PEV is analyzed as a regulation services provider in the power system with high wind power penetrations. The western Danish power system where the total share of annual wind power production is more than 27% of the electrical energy...

  15. Development of two series ingnitron based crowbar protection system for 42 GHz and 82.6 GHz gyroton in SST-1

    International Nuclear Information System (INIS)

    Dhorajiya, Pragnesh; Dalakoti, Shefali; Patel, Harshida; Ingle, Krunal; Patel, Jatin; Sathyanarayana, K.; Rajanbabu; Shukla, B.K.

    2013-01-01

    Gyrotrons are used to generate the high power at microwave frequency that is used to heat the plasma inside a Tokamak. A conventional high voltage power supply is used for the testing of 82.6 GHz, 200 kW/CW and 42 GHz, 500 kW/500ms gyrotrons at our institute. Its maximum operating cathode parameters are -55 kV DC, 20 A. Like any other High RF power tubes gyrotrons need to be protected against arc faults within the tube. If the energy dumped in such arc fault is more than the critical crater energy of the tube, irreparable damage can occur inside the RF tube or microwave tube and rendering it useless. The specified maximum fault energy for the 42 GHz and 82.6 GHz gyrotrons is 10 joules. When conventional HVDC power supplies feed high power RF tubes or microwave tubes, a reliable crowbar protection is required which is tested separately to limit the energy to the tube in case of any type of fault to assure the tube safety. Two series ignitron (NL-37248) based crowbar system developed in-house is used to limit the arc fault energy under the acceptance level by diverting the fault current from the load or Gyrotron. Fault current diversion and interruption are initiated by the sensing element and protection system. The required protection cards are designed and developed in-house and required performance is achieved. With this crowbar system the high voltage switch-off to the gyrotron is achieved within 5 μsec after occurrence of critical faults. The crowbar is tested for voltage hold-off up to 80 kV DC. This paper presents the critical requirement of the time delay for the fault sensing and crowbar trigger generation and necessary protections that are incorporated with the ignitron switch crowbar like over voltage, pulsed over current and continuous over current. The crowbar system developed in-house, tested at rated value. The results obtained during the stand-alone tests and commissioning tests are also mentioned. Using this crowbar system the high voltage power

  16. Development of high power models of four-slot Annular Coupled Structure

    International Nuclear Information System (INIS)

    Kageyama, T.; Morozumi, Y.; Yoshino, K.; Yamazaki, Y.

    1994-01-01

    A π/2-mode standing-wave linac (f=1.296 GHz) of an Annular Coupled Structure (ACS) has been developed for the 1-GeV proton linac of the Japanese Hadron Project (JHP). This ACS has four coupling slots between accelerating and coupling cells in order to suppress higher order mode mixing with the π/2 coupling mode. High-β(β=v/c=0.78) and low-β(0.52) prototypes were constructed and tested up to each design RF power. Concerning the effect of the coupling slots on the fields of a coupled-cavity linac, it was found that the slot configuration of the side-coupled structure (SCS) tilts the accelerating field. On the other hand, the four-slot configuration of the ACS gives an almost axially symmetric accelerating field to the beam. (author)

  17. Low Cost SU8 Based Above IC Process for High Q RF Power Inductors Integration

    International Nuclear Information System (INIS)

    Ghannam, A.; Bourrier, D.; Viallon, Ch.; Parra, Th.

    2011-01-01

    This paper presents a new process for integration of high-Q RF power inductors above low resistivity silicon substrates. The process uses the SU8 resin as a dielectric layer. The aim of using the SU8 is to form thick dielectric layer that can enhance the performance of the inductors. The flexibility of the process enables the possibility to realize complex shaped planar inductors with various dielectric and metal thicknesses to meet the requirements of the application. Q values of 55 at 5 GHz has been demonstrated for an inductance value of 0.8 nH using a 60 μm thick SU8 layer and 30 μm thick copper ribbons. (author)

  18. High power diode laser remelting of metals

    International Nuclear Information System (INIS)

    Chmelickova, H; Tomastik, J; Ctvrtlik, R; Supik, J; Nemecek, S; Misek, M

    2014-01-01

    This article is focused on the laser surface remelting of the steel samples with predefined overlapping of the laser spots. The goal of our experimental work was to evaluate microstructure and hardness both in overlapped zone and single pass ones for three kinds of ferrous metals with different content of carbon, cast iron, non-alloy structural steel and tool steel. High power fibre coupled diode laser Laserline LDF 3600-100 was used with robotic guided processing head equipped by the laser beam homogenizer that creates rectangular beam shape with uniform intensity distribution. Each sample was treated with identical process parameters - laser power, beam diameter, focus position, speed of motion and 40% spot overlap. Dimensions and structures of the remelted zone, zone of the partial melting, heat affected zone and base material were detected and measured by means of laser scanning and optical microscopes. Hardness progress in the vertical axis of the overlapped zone from remelted surface layer to base material was measured and compared with the hardness of the single spots. The most hardness growth was found for cast iron, the least for structural steel. Experiment results will be used to processing parameters optimization for each tested material separately.

  19. High resolving power spectrometer for beam analysis

    International Nuclear Information System (INIS)

    Moshammer, H.W.; Spencer, J.E.

    1992-03-01

    We describe a system designed to analyze the high energy, closely spaced bunches from individual RF pulses. Neither a large solid angle nor momentum range is required so this allows characteristics that appear useful for other applications such as ion beam lithography. The spectrometer is a compact, double-focusing QBQ design whose symmetry allows the Quads to range between F or D with a correspondingly large range of magnifications, dispersion and resolving power. This flexibility insures the possibility of spatially separating all of the bunches along the focal plane with minimal transverse kicks and bending angle for differing input conditions. The symmetry of the system allows a simple geometric interpretationof the resolving power in terms of thin lenses and ray optics. We discuss the optics and the hardware that is proposed to measure emittance, energy, energy spread and bunch length for each bunch in an RF pulse train for small bunch separations. We also discuss how to use such measurements for feedback and feedforward control of these bunch characteristics as well as maintain their stability. 2 refs

  20. Improved Collectors for High Power Gyrotrons

    International Nuclear Information System (INIS)

    Ives, R. Lawrence; Singh, Amarjit; Read, Michael; Borchard, Philipp; Neilson, Jeff

    2009-01-01

    High power gyrotrons are used for electron cyclotron heating, current drive and parasitic mode suppression in tokamaks for fusion energy research. These devices are crucial for successful operation of many research programs around the world, including the ITER program currently being constructed in France. Recent gyrotron failures resulted from cyclic fatigue of the copper material used to fabricated the collectors. The techniques used to collect the spent beam power is common in many gyrotrons produced around the world. There is serious concern that these tubes may also be at risk from cyclic fatigue. This program addresses the cause of the collector failure. The Phase I program successfully demonstrated feasibility of a mode of operation that eliminates the cyclic operation that caused the failure. It also demonstrated that new material can provide increased lifetime under cyclic operation that could increase the lifetime by more than on order of magnitude. The Phase II program will complete that research and develop a collector that eliminates the fatigue failures. Such a design would find application around the world.

  1. 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....

  2. High Power Flex-Propellant Arcjet Performance

    Science.gov (United States)

    Litchford, Ron J.

    2011-01-01

    implied nearly frozen flow in the nozzle and yielded performance ranges of 800-1100 sec for hydrogen and 400-600 sec for ammonia. Inferred thrust-to-power ratios were in the range of 30-10 lbf/MWe for hydrogen and 60-20 lbf/MWe for ammonia. Successful completion of this test series represents a fundamental milestone in the progression of high power arcjet technology, and it is hoped that the results may serve as a reliable touchstone for the future development of MW-class regeneratively-cooled flex-propellant plasma rockets.

  3. Design of high current bunching system and high power fast Faraday cup for high current LEBT at VECC

    International Nuclear Information System (INIS)

    Anuraag Misra, A.; Pandit, B.V.S.; Gautam Pal, C.

    2011-01-01

    A high current microwave ion source as described is currently operational at VECC. We are able to optimize 6.4 mA of proton current in the LEBT line of ion source. The cyclotron type of accelerators accept only a fraction of DC ion beam coming from ion source so a ion beam buncher is needed to increase the accepted current into the cyclotron. The buncher described in this paper is unique in its kind as it has to handle high beam loading power upto 400 W as it is designed to bunch few mA of proton beam currents at 80 keV beam energy. A sinusoidal quarter wave RF structure has been chosen to bunch the high current beam due to high Q achievable in comparison with other configurations. This buncher has been designed using CST Microwave studio 3D advanced code since the design frequency of our buncher is 42 MHz, we have provided the RF and vacuum window near the drift tube of buncher to avoid vacuum and multipacting problems and to keep maximum volume in air region. There is a provision of multipacting interlocks to shut off amplifier during multipacting. We have carried out a detailed electromagnetic and thermal design of the buncher in CST Microwave studio and simulated values of unloaded Q was calculated be 4000. We have estimated a power of 400 W to achieve gap (designed) voltage of 10 kV. This buncher is in advanced stage of fabrication. A high power fast Faraday cup is also designed to characterize the above mentioned high current bunching system. The fast Faraday cup is designed in 50 Ω coaxial geometry to transmit fast pulse of bunched ion beam. The design of Faraday cup was completed using ANSYS HFSS and a bandwidth of 1.75 GHz was achieved this faraday cup design was different from conventional Faraday cup design as we have designed the support and cooling lines at such a place on Faraday cup which do not disturb the electrical impedance of the cup. (author)

  4. Upgrade of the SLAC SLED II Pulse Compression System Based on Recent High Power Tests

    International Nuclear Information System (INIS)

    Vlieks, A.E.; Fowkes, W.R.; Loewen, R.J.; Tantawi, S.G.

    2011-01-01

    In the Next Linear Collider (NLC) it is expected that the high power rf components be able to handle peak power levels in excess of 400 MW. We present recent results of high power tests designed to investigate the RF breakdown limits of the X-band pulse compression system used at SLAC. (SLED-II). Results of these tests show that both the TE 01 -TE 10 mode converter and the 4-port hybrid have a maximum useful power limit of 220-250 MW. Based on these tests, modifications of these components have been undertaken to improve their peak field handling capability. Results of these modifications will be presented. As part of an international effort to develop a new 0.5-1.5 TeV electron-positron linear collider for the 21st century, SLAC has been working towards a design, referred to as 'The Next Linear Collider' (NLC), which will operate at 11.424 GHz and utilize 50-75 MW klystrons as rf power sources. One of the major challenges in this design, or any other design, is how to generate and efficiently transport extremely high rf power from a source to an accelerator structure. SLAC has been investigating various methods of 'pulse compressing' a relatively wide rf pulse ((ge) 1 μs) from a klystron into a narrower, but more intense, pulse. Currently a SLED-II pulse compression scheme is being used at SLAC in the NLC Test Accelerator (NLCTA) and in the Accelerator Structures Test Area (ASTA) to provide high rf power for accelerator and component testing. In ASTA, a 1.05 μs pulse from a 50 MW klystron was successfully pulse compressed to 205 MW with a pulse width of 150 ns. Since operation in NLC will require generating and transporting rf power in excess of 400 MW it was decided to test the breakdown limits of the SLED-II rf components in ASTA with rf power up to the maximum available of 400 MW. This required the combining of power from two 50 MW klystrons and feeding the summed power into the SLED-II pulse compressor. Results from this experiment demonstrated that two of

  5. Splitting of high power, cw proton beams

    Directory of Open Access Journals (Sweden)

    Alberto Facco

    2007-09-01

    Full Text Available A simple method for splitting a high power, continuous wave (cw proton beam in two or more branches with low losses has been developed in the framework of the EURISOL (European Isotope Separation On-Line Radioactive Ion Beam Facility design study. The aim of the system is to deliver up to 4 MW of H^{-} beam to the main radioactive ion beam production target, and up to 100 kW of proton beams to three more targets, simultaneously. A three-step method is used, which includes magnetic neutralization of a fraction of the main H^{-} beam, magnetic splitting of H^{-} and H^{0}, and stripping of H^{0} to H^{+}. The method allows slow raising and individual fine adjustment of the beam intensity in each branch.

  6. Survey on modern pulsed high power lasers

    International Nuclear Information System (INIS)

    Witte, K.J.

    1985-01-01

    The requirements to be met by lasers for particle acceleration are partially similar to those already known for fusion lasers. The power level wanted in both caes is up to 100 TW or even more. The pulse durations favourable for laser accelerators are in the range from 1 ps to 1000 ps whereas fusion lasers require several ns. The energy range for laser accelerators is thus correspondingly smaller than that for fusion lasers: 1-100 kJ versus several 100 kJ. The design criteria of lasers meeting the requirements are discussed in the following. The CO 2 , iodine, Nd:glass and excimer lasers are treated in detail. The high repetition rate aspect will not be particularly addressed since for the present generation of lasers the wanted rates of far above 1 Hz are completely out of scope. Moreover, for the demonstration of principle these rates are not needed. (orig./HSI)

  7. QED studies using high-power lasers

    International Nuclear Information System (INIS)

    Mattias Marklund

    2010-01-01

    Complete text of publication follows. The event of extreme lasers, which intensities above 10 22 W/cm 2 will be reached on a routine basis, will give us opportunities to probe new aspects of quantum electrodynamics. In particular, the non-trivial properties of the quantum vacuum can be investigated as we reach previously unattainable laser intensities. Effects such as vacuum birefringence and pair production in strong fields could thus be probed. The prospects of obtaining new insights regarding the non-perturbative structure of quantum field theories shows that the next generation laser facilities can be important tool for fundamental physical studies. Here we aim at giving a brief overview of such aspects of high-power laser physics.

  8. High-power laser diodes with high polarization purity

    Science.gov (United States)

    Rosenkrantz, Etai; Yanson, Dan; Peleg, Ophir; Blonder, Moshe; Rappaport, Noam; Klumel, Genady

    2017-02-01

    Fiber-coupled laser diode modules employ power scaling of single emitters for fiber laser pumping. To this end, techniques such as geometrical, spectral and polarization beam combining (PBC) are used. For PBC, linear polarization with high degree of purity is important, as any non-perfectly polarized light leads to losses and heating. Furthermore, PBC is typically performed in a collimated portion of the beams, which also cancels the angular dependence of the PBC element, e.g., beam-splitter. However, we discovered that single emitters have variable degrees of polarization, which depends both on the operating current and far-field divergence. We present data to show angle-resolved polarization measurements that correlate with the ignition of high-order modes in the slow-axis emission of the emitter. We demonstrate that the ultimate laser brightness includes not only the standard parameters such as power, emitting area and beam divergence, but also the degree of polarization (DoP), which is a strong function of the latter. Improved slow-axis divergence, therefore, contributes not only to high brightness but also high beam combining efficiency through polarization.

  9. Large power electron tubes for high frequency heating

    International Nuclear Information System (INIS)

    Okamoto, Tadashi; Sato, Hisaaki.

    1988-01-01

    On the large power electron tubes used for electron cyclotron heating, lower hybrid resonance frequency heating, and ion cyclotron range of frequency heating, namely gyrotron, klystron and quadrupole tube, the features, the present status of development, the construction, the principle and so on are explained. The research and development of gyrotrons are most advanced in USSR, the inventor. The course of the development of gyrotrons in foreign countries and in Japan is described. There are many variants of gyrotrons, for example whispering gallery mode, klystron type, backward wave oscillator type, gyro-peniotron and others. The principle of gyrotrons is explained, and about the examples of the developed gyrotrons, the design parameters are shown. For the purpose of using for the LHRF heating in JT-60, a superlarge power klystron of 1 MW output at 2 GHz frequency, which is the largest class in the world, has been developed. Its total length is 2.7 m, and weight is 1.5 t. It features, construction, function and performance are reported. The trend of large power quadrupole tubes is toward stable action with large power in VHF zone, and the typical products in USA and Europe are shown. (Kako, I.)

  10. Amplifier Module for 260-GHz Band Using Quartz Waveguide Transitions

    Science.gov (United States)

    Padmanabhan, Sharmila; Fung, King Man; Kangaslahti, Pekka P.; Peralta, Alejandro; Soria, Mary M.; Pukala, David M.; Sin, Seth; Samoska, Lorene A.; Sarkozy, Stephen; Lai, Richard

    2012-01-01

    Packaging of MMIC LNA (monolithic microwave integrated circuit low-noise amplifier) chips at frequencies over 200 GHz has always been problematic due to the high loss in the transition between the MMIC chip and the waveguide medium in which the chip will typically be used. In addition, above 200 GHz, wire-bond inductance between the LNA and the waveguide can severely limit the RF matching and bandwidth of the final waveguide amplifier module. This work resulted in the development of a low-loss quartz waveguide transition that includes a capacitive transmission line between the MMIC and the waveguide probe element. This capacitive transmission line tunes out the wirebond inductance (where the wire-bond is required to bond between the MMIC and the probe element). This inductance can severely limit the RF matching and bandwidth of the final waveguide amplifier module. The amplifier module consists of a quartz E-plane waveguide probe transition, a short capacitive tuning element, a short wire-bond to the MMIC, and the MMIC LNA. The output structure is similar, with a short wire-bond at the output of the MMIC, a quartz E-plane waveguide probe transition, and the output waveguide. The quartz probe element is made of 3-mil quartz, which is the thinnest commercially available material. The waveguide band used is WR4, from 170 to 260 GHz. This new transition and block design is an improvement over prior art because it provides for better RF matching, and will likely yield lower loss and better noise figure. The development of high-performance, low-noise amplifiers in the 180-to- 700-GHz range has applications for future earth science and planetary instruments with low power and volume, and astrophysics array instruments for molecular spectroscopy. This frequency band, while suitable for homeland security and commercial applications (such as millimeter-wave imaging, hidden weapons detection, crowd scanning, airport security, and communications), also has applications to

  11. Ultra High Power and Efficiency Space Traveling-Wave Tube Amplifier Power Combiner with Reduced Size and Mass for NASA Missions

    Science.gov (United States)

    Simons, Rainee N.; Wintucky, Edwin G.; Wilson, Jeffrey D.; Force, Dale A.

    2009-01-01

    In the 2008 International Microwave Symposium (IMS) Digest version of our paper, recent advances in high power and efficiency space traveling-wave tube amplifiers (TWTAs) for NASA s space-to-Earth communications are presented. The RF power and efficiency of a new K-Band amplifier are 40 W and 50 percent and that of a new Ka-Band amplifier are 200 W and 60 percent. An important figure-of-merit, which is defined as the ratio of the RF power output to the mass (W/kg) of a TWT, has improved by a factor of ten over the previous generation Ka-Band devices. In this extended paper, a high power, high efficiency Ka-band combiner for multiple TWTs, based on a novel hybrid magic-T waveguide circuit design, is presented. The measured combiner efficiency is as high as 90 percent. In addition, at the design frequency of 32.05 GHz, error-free uncoded BPSK/QPSK data transmission at 8 megabits per second (Mbps), which is typical for deep space communications is demonstrated. Furthermore, QPSK data transmission at 622 Mbps is demonstrated with a low bit error rate of 2.4x10(exp -8), which exceeds the deep space state-of-the-art data rate transmission capability by more than two orders of magnitude. A potential application of the TWT combiner is in deep space communication systems for planetary exploration requiring transmitter power on the order of a kilowatt or higher.

  12. High technology supporting nuclear power industry in CRIEPI

    International Nuclear Information System (INIS)

    Ueda, Nobuyuki

    2009-01-01

    As a central research institute of electric power industry, Central Research Institute of Electric Power Industry (CRIEPI) has carried out R and D on broad range of topics such as power generation, power transmission, power distribution, power application and energy economics and society, aiming to develop prospective and advanced technologies, fundamental reinforce technologies and next-generation core technologies. To realize low-carbon society to cope with enhancement of global environmental issues, nuclear power is highly recommended as large-scale power with low-carbon emission. At the new start of serial explanation on advanced technologies, R and D on electric power industry was outlined. (T. Tanaka)

  13. Packaging of microwave integrated circuits operating beyond 100 GHz

    Science.gov (United States)

    Samoska, L.; Daniel, E.; Sokolov, V.; Sommerfeldt, S.; Bublitz, J.; Olson, K.; Gilbert, B.; Chow, D.

    2002-01-01

    Several methods of packaging high speed (75-330 GHz) InP HEMT MMIC devices are discussed. Coplanar wirebonding is presented with measured insertion loss of less than 0.5dB and return loss better than -17 dB from DC to 110 GHz. A motherboard/daughterboard packaging scheme is presented which supports minimum loss chains of MMICs using this coplanar wirebonding method. Split waveguide block packaging approaches are presented in G-band (140-220 GHz) with two types of MMIC-waveguide transitions: E-plane probe andantipodal finline.

  14. Switching transients in high-frequency high-power converters using power MOSFET's

    Science.gov (United States)

    Sloane, T. H.; Owen, H. A., Jr.; Wilson, T. G.

    1979-01-01

    The use of MOSFETs in a high-frequency high-power dc-to-dc converter is investigated. Consideration is given to the phenomena associated with the paralleling of MOSFETs and to the effect of stray circuit inductances on the converter circuit performance. Analytical relationships between various time constants during the turning-on and turning-off intervals are derived which provide estimates of plateau and peak levels during these intervals.

  15. Test results from the LLNL 250 GHz CARM experiment

    International Nuclear Information System (INIS)

    Kulke, B.; Caplan, M.; Bubp, D.; Houck, T.; Rogers, D.; Trimble, D.; VanMaren, R.; Westenskow, G.; McDermott, D.B.; Luhmann, N.C. Jr.; Danly, B.

    1991-01-01

    The authors have completed the initial phase of a 250 GHz CARM experiment, driven by the 2 MeV, 1 kA, 30 ns induction linac at the LLNL ARC facility. A non-Brillouin, solid, electron beam is generated from a flux-threaded, thermionic cathode. As the beam traverses a 10 kG plateau produced by a superconducting magnet, ten percent of the beam energy is converted into rotational energy in a bifilar helix wiggler that produces a spiraling, 50 G, transverse magnetic field. The beam is then compressed to a 5 mm diameter as it drifts into a 30 kG plateau. For the present experiment, the CARM interaction region consisted of a single Bragg section resonator, followed by a smooth-bore amplifier section. Using high-pass filters, they have observed broadband output signals estimated to be at the several megawatt level in the range 140 to over 230 GHz. This is consistent with operation as a superradiant amplifier. Simultaneously, they also observed K a band power levels near 3 MW

  16. Test results from the LLNL 250 GHz CARM experiment

    International Nuclear Information System (INIS)

    Kulke, B.; Caplan, M.; Bubp, D.; Houck, T.; Rogers, D.; Trimble, D.; VanMaren, R.; Westenskow, G.; McDermott, D.B.; Luhmann, N.C. Jr.; Danly, B.

    1991-05-01

    We have completed the initial phase of a 250 GHz CARM experiment, driven by the 2 MeV, 1 kA, 30 ns induction linac at the LLNL ARC facility. A non-Brillouin, solid, electron beam is generated from a flux-threaded, thermionic cathode. As the beam traverses a 10 kG plateau produced by a superconducting magnet, ten percent of the beam energy is converted into rotational energy in a bifilar helix wiggler that produces a spiraling, 50 G, transverse magnetic field. The beam is then compressed to a 5 mm diameter as it drifts into a 30 kG plateau. For the present experiment, the CARM interaction region consisted of a single Bragg section resonator, followed by a smooth-bore amplifier section. Using high-pass filters, we have observed broadband output signals estimated to be at the several megawatt level in the range 140 to over 230 GHz. This is consistent with operation as a superradiant amplifier. Simultaneously, we also observed K a band power levels near 3 MW

  17. Chaos in high-power high-frequency gyrotrons

    International Nuclear Information System (INIS)

    Airila, M.

    2004-01-01

    Gyrotron interaction is a complex nonlinear dynamical process, which may turn chaotic in certain circumstances. The emergence of chaos renders dynamical systems unpredictable and causes bandwidth broadening of signals. Such effects would jeopardize the prospect of advanced gyrotrons in fusion. Therefore, it is important to be aware of the possibility of chaos in gyrotrons. There are three different chaos scenarios closely related to the development of high-power gyrotrons: First, the onset of chaos in electron trajectories would lead to difficulties in the design and efficient operation of depressed potential collectors, which are used for efficiency enhancement. Second, the radio-frequency signal could turn chaotic, decreasing the output power and the spectral purity of the output signal. As a result, mode conversion, transmission, and absorption efficiencies would be reduced. Third, spatio-temporal chaos in the resonator field structure can set a limit for the use of large-diameter interaction cavities and high-order TE modes (large azimuthal index) allowing higher generated power. In this thesis, the issues above are addressed with numerical modeling. It is found that chaos in electron residual energies is practically absent in the parameter region corresponding to high efficiency. Accordingly, depressed collectors are a feasible solution also in advanced high-power gyrotrons. A new method is presented for straightforward numerical solution of the one-dimensional self-consistent time-dependent gyrotron equations, and the method is generalized to two dimensions. In 1D, a chart of gyrotron oscillations is calculated. It is shown that the regions of stationary oscillations, automodulation, and chaos have a complicated topology in the plane of generalized gyrotron variables. The threshold current for chaotic oscillations exceeds typical operating currents by a factor of ten. However, reflection of the output signal may significantly lower the threshold. 2D

  18. High-performance 16-way Ku-band radial power combiner based on the TE01-circular waveguide mode

    Science.gov (United States)

    Montejo-Garai, José R.; Saracho-Pantoja, Irene O.; Ruiz-Cruz, Jorge A.; Rebollar, Jesús M.

    2018-03-01

    This work presents a 16-way Ku-band radial power combiner for high power and high frequency applications, using the very low loss TE01 circular waveguide mode. The accomplished design shows an excellent performance: the experimental prototype has a return loss better than 30 dB, with a balance for the amplitudes of (±0.15 dB) and (±2.5°) for the phases, in a 16.7% fractional bandwidth (2 GHz centered at 12 GHz). For obtaining these outstanding specifications, required, for instance, in high-frequency amplification or on plasma systems, a rigorous step-by-step procedure is presented. First, a high-purity mode transducer has been designed, from the TE10 mode in the rectangular waveguide to the TE01 mode in the circular waveguide, with very high attenuation (>50 dB) for the other propagating and evanescent modes in the circular waveguide. This transducer has been manufactured and measured in a back-to-back configuration, validating the design process. Second, an E-plane 16-way radial power divider has been designed, where the power is coupled from the 16 non-reduced-height radial standard waveguides into the TE01 circular waveguide mode, improving the insertion loss response and removing the usual tapered transformers of previous designs limiting the power handling. Finally, both the transducer and the divider have been assembled to make the final radial combiner. The prototype has been carefully manufactured, showing very good agreement between the measurements and the full-wave simulations.

  19. Power transistor module for high current applications

    International Nuclear Information System (INIS)

    Cilyo, F.F.

    1975-01-01

    One of the parts needed for the control system of the 400-GeV accelerator at Fermilab was a power transistor with a safe operating area of 1800A at 50V, dc current gain of 100,000 and 20 kHz bandwidth. Since the commercially available discrete devices and power hybrid packages did not meet these requirements, a power transistor module was developed which performed satisfactorily. By connecting 13 power transistors in parallel, with due consideration for network and heat dissipation problems, and by driving these 13 with another power transistor, a super power transistor is made, having an equivalent current, power, and safe operating area capability of 13 transistors. For higher capabilities, additional modules can be conveniently added. (auth)

  20. 1.5-V-threshold-voltage Schottky barrier normally-off AlGaN/GaN high-electron-mobility transistors with f T/f max of 41/125 GHz

    Science.gov (United States)

    Hou, Bin; Ma, Xiaohua; Yang, Ling; Zhu, Jiejie; Zhu, Qing; Chen, Lixiang; Mi, Minhan; Zhang, Hengshuang; Zhang, Meng; Zhang, Peng; Zhou, Xiaowei; Hao, Yue

    2017-07-01

    In this paper, a normally-off AlGaN/GaN high-electron-mobility transistors (HEMT) fabricated using inductively coupled plasma (ICP) CF4 plasma recessing and an implantation technique is reported. A gate-to-channel distance of ˜10 nm and an equivalent negative fluorine sheet charge density of -1.21 × 1013 cm-2 extracted using a simple threshold voltage (V th) analytical model result in a high V th of 1.5 V, a peak transconductance of 356 mS/mm, and a subthreshold slope of 133 mV/decade. A small degradation of channel mobility leads to a high RF performance with f T/f max of 41/125 GHz, resulting in a record high f T × L g product of 10.66 GHz·µm among Schottky barrier AlGaN/GaN normally-off HEMTs with V th exceeding 1 V, to the best of our knowledge.

  1. Initial high-power testing of the ATF [Advanced Toroidal Facility] ECH [electron cyclotron heating] system

    International Nuclear Information System (INIS)

    White, T.L.; Bigelow, T.S.; Kimrey, H.D. Jr.

    1987-01-01

    The Advanced Toroidal Facility (ATF) is a moderate aspect ratio torsatron that will utilize 53.2 GHz 200 kW Electron Cyclotron Heating (ECH) to produce nearly current-free target plasmas suitable for subsequent heating by strong neutral beam injection. The initial configuration of the ECH system from the gyrotron to ATF consists of an optical arc detector, three bellows, a waveguide mode analyzer, two TiO 2 mode absorbers, two 90 0 miter bends, two waveguide pumpouts, an insulating break, a gate valve, and miscellaneous straight waveguide sections feeding a launcher radiating in the TE 02 mode. Later, a focusing Vlasov launcher will be added to beam the ECH power to the saddle point in ATF magnetic geometry for optimum power deposition. The ECH system has several unique features; namely, the entire ECH system is evacuated, the ECH system is broadband, forward power is monitored by a newly developed waveguide mode analyzer, phase correcting miter bends will be employed, and the ECH system will be capable of operating short pulse to cw. Initial high-power tests show that the overall system efficiency is 87%. The waveguide mode analyzer shows that the gyrotron mode output consists of 13% TE 01 , 82.6% TE 02 , 2.5% TE 03 , and 1.9% TE 04 . 4 refs

  2. Initial operation of a high-power quasi-optical gyrotron

    International Nuclear Information System (INIS)

    Fliflet, A.W.; Hargreaves, T.A.; Manheimer, W.M.; Fischer, R.P.; Barsanti, M.L.

    1990-01-01

    Results from the initial operating of a high-power quasi-optical gyrotron based on the 90-kV 50-A Varian VUW-8144 electron gun are reported. The output power and efficiency have been measured for a resonator mirror separation of 19.4 cm with a magnetic field of 4.95 T, corresponding to resonator output coupling of 1.9%, and for a resonator mirror separation of 21.4 cm with a magnetic field of 4.7 T, corresponding to a resonator output coupling of 3.1%. Operation was multimoded with 3--6 modes excited in the range of 125--130 GHz for the 4.95-T magnetic field. A peak efficiency of 15% at an output power of 161 kW was obtained for a gun voltage of 93 kV and a current of 12 A. A peak-output power of 364 kW at an efficiency of 10% was obtained at a voltage of 95.6 kV and 37.5 A

  3. HIGH POWER TESTS OF A MULTIMODE X-BAND RF DISTRIBUTION SYSTEMS

    International Nuclear Information System (INIS)

    Tantawi, S

    2004-01-01

    We present a multimode X-band rf pulse compression system suitable for the Next Linear Collider (NLC). The NLC main linacs operate at 11.424 GHz. A single NLC rf unit is required which produce 400 ns pulses with 600 MW of peak power. Each rf unit should power approximately 5 meters of accelerator structures. These rf units consist of two 75 MW klystrons and a dual-moded resonant delay line pulse compression system [1] that produce a flat output pulse. The pulse compression system components are all over moded and most components are design to operate with two modes at the same time. This approach allows increasing the power handling capabilities of the system while maintain a compact inexpensive system. We detail the design of this system and present experimental cold test results. The high power testing of the system is verified using four 50-MW solenoid focused klystrons. These Klystrons should be able to push the system beyond NLC requirements

  4. High power accelerator for environmental application

    International Nuclear Information System (INIS)

    Han, B.; Kim, J.K.; Kim, Y.R.; Kim, S.M.

    2011-01-01

    The problems of environmental damage and degradation of natural resources are receiving increasing attention throughout the world. The increased population, higher living standards, increased urbanization and enhanced industrial activities of humankind are all leading to degradation of the environment. Increasing urbanization has been accompanied by significant environmental pollution, given the seriousness of the situation and future risk of crises, there is an urgent need to develop the efficient technologies including economical treatment methods. Therefore, cost-effective treatment of the stack gases, wastewater and sludge containing refractory pollutant with electron beam is actively studied in EB TECH Co. Electron beam treatment of such hazardous wastes is caused by the decomposition of pollutants as a result of their reactions with highly reactive species formed from radiolysis. However, to have advantages over existing processes, the electron beam process should have cost-effective and reliable in operation. Therefore high power accelerators (400kW~1MW) are developed for environmental application and they show the decrease in the cost of construction and operation of electron beam plant. In other way to reduce the cost for treatment, radical reactions accompanied by the other processes are introduced, and the synergistic effect upon the use of combined methods such as electron beam treatment with catalytic system, biological treatment and physico-chemical adsorption and others also show the improvement of the effect of electron beam treatment. (author)

  5. High-average-power solid state lasers

    International Nuclear Information System (INIS)

    Summers, M.A.

    1989-01-01

    In 1987, a broad-based, aggressive R ampersand D program aimed at developing the technologies necessary to make possible the use of solid state lasers that are capable of delivering medium- to high-average power in new and demanding applications. Efforts were focused along the following major lines: development of laser and nonlinear optical materials, and of coatings for parasitic suppression and evanescent wave control; development of computational design tools; verification of computational models on thoroughly instrumented test beds; and applications of selected aspects of this technology to specific missions. In the laser materials areas, efforts were directed towards producing strong, low-loss laser glasses and large, high quality garnet crystals. The crystal program consisted of computational and experimental efforts aimed at understanding the physics, thermodynamics, and chemistry of large garnet crystal growth. The laser experimental efforts were directed at understanding thermally induced wave front aberrations in zig-zag slabs, understanding fluid mechanics, heat transfer, and optical interactions in gas-cooled slabs, and conducting critical test-bed experiments with various electro-optic switch geometries. 113 refs., 99 figs., 18 tabs

  6. High power accelerator for environmental application

    Energy Technology Data Exchange (ETDEWEB)

    Han, B.; Kim, J. K.; Kim, Y. R.; Kim, S. M. [EB-TECH Co., Ltd., Yuseong-gu Daejeon (Korea, Republic of)

    2011-07-01

    The problems of environmental damage and degradation of natural resources are receiving increasing attention throughout the world. The increased population, higher living standards, increased urbanization and enhanced industrial activities of humankind are all leading to degradation of the environment. Increasing urbanization has been accompanied by significant environmental pollution, given the seriousness of the situation and future risk of crises, there is an urgent need to develop the efficient technologies including economical treatment methods. Therefore, cost-effective treatment of the stack gases, wastewater and sludge containing refractory pollutant with electron beam is actively studied in EB TECH Co. Electron beam treatment of such hazardous wastes is caused by the decomposition of pollutants as a result of their reactions with highly reactive species formed from radiolysis. However, to have advantages over existing processes, the electron beam process should have cost-effective and reliable in operation. Therefore high power accelerators (400kW~1MW) are developed for environmental application and they show the decrease in the cost of construction and operation of electron beam plant. In other way to reduce the cost for treatment, radical reactions accompanied by the other processes are introduced, and the synergistic effect upon the use of combined methods such as electron beam treatment with catalytic system, biological treatment and physico-chemical adsorption and others also show the improvement of the effect of electron beam treatment. (author)

  7. High power accelerators and wastewater treatment

    International Nuclear Information System (INIS)

    Han, B.; Kim, J.K.; Kim, Y.R.; Kim, S.M.; Makaov, I.E.; Ponomarev, A.V.

    2006-01-01

    The problems of environmental damage and degradation of natural resources are receiving increasing attention throughout the world. The increased population, higher living standards, increased urbanization and enhanced industrial activities of humankind are all leading to degradation of the environment. Increasing urbanization has been accompanied by significant water pollution. Given the seriousness of the situation and future risk of crises, there is an urgent need to develop the water-efficient technologies including economical treatment methods of wastewater and polluted water. Therefore, cost-effective treatment of the municipal and industrial wastewater containing refractory pollutant with electron beam is actively studied in EB TECH Co.. Electron beam treatment of wastewater is caused by the decomposition of pollutants as a result of their reactions with highly reactive species formed from water radiolysis (hydrated electron, OH free radical and H atom). However, to have advantages over existing processes, the electron beam process should have cost-effective and reliable in operation. Therefore high power accelerators (400kW∼1MW) are developed for environmental application and they show the decrease in the cost of construction and operation of electron beam plant. In other way to reduce the cost for wastewater treatment, radical reactions accompanied by the other processes are introduced, and the synergistic effect upon the use of combined methods such as electron beam treatment with ozonation, biological treatment and physico-chemical adsorption and others also show the improvement of the effect of electron beam treatment for the wastewater purification. (author)

  8. High power diode lasers converted to the visible

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin; Hansen, Anders Kragh; Andersen, Peter E.

    2017-01-01

    High power diode lasers have in recent years become available in many wavelength regions. However, some spectral regions are not well covered. In particular, the visible spectral range is lacking high power diode lasers with good spatial quality. In this paper, we highlight some of our recent...... results in nonlinear frequency conversion of high power near infrared diode lasers to the visible spectral region....

  9. Design of a high power TM01 mode launcher optimized for manufacturing by milling

    Energy Technology Data Exchange (ETDEWEB)

    Dal Forno, Massimo [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2016-12-15

    Recent research on high-gradient rf acceleration found that hard metals, such as hard copper and hard copper-silver, have lower breakdown rate than soft metals. Traditional high-gradient accelerating structures are manufactured with parts joined by high-temperature brazing. The high temperature used in brazing makes the metal soft; therefore, this process cannot be used to manufacture structures out of hard metal alloys. In order to build the structure with hard metals, the components must be designed for joining without high-temperature brazing. One method is to build the accelerating structures out of two halves, and join them by using a low-temperature technique, at the symmetry plane along the beam axis. The structure has input and output rf power couplers. We use a TM01 mode launcher as a rf power coupler, which was introduced during the Next Linear Collider (NLC) work. The part of the mode launcher will be built in each half of the structure. This paper presents a novel geometry of a mode launcher, optimized for manufacturing by milling. The coupler was designed for the CERN CLIC working frequency f = 11.9942 GHz; the same geometry can be scaled to any other frequency.

  10. Development of multi-channel high power rectangular RF window for LHCD system employing high temperature vacuum brazing technique

    International Nuclear Information System (INIS)

    Sharma, P K; Ambulkar, K K; Parmar, P R; Virani, C G; Thakur, A L; Joshi, L M; Nangru, S C

    2010-01-01

    A 3.7 GHz., 120 kW (pulsed), lower hybrid current drive (LHCD) system is employed to drive non-inductive plasma current in ADITYA tokamak. The rf power is coupled to the plasma through grill antenna and is placed in vacuum environment. A vacuum break between the pressurized transmission line and the grill antenna is achieved with the help of a multi (eight) channel rectangular RF vacuum window. The phasing between adjacent channels of 8-channel window (arranged in two rows) is important for launching lower hybrid waves and each channel should have independent vacuum window so that phase information is retained. The geometrical parameter of the grill antenna, like periodicity (9mm), channel dimensions (cross sectional dimension of 76mm x 7mm), etc. is to be maintained. These design constraint demanded a development of a multi channel rectangular RF vacuum window. To handle rf losses and thermal effects, high temperature vacuum brazing techniques is desired. Based on the above requirements we have successfully developed a multi channel rectangular rf vacuum window employing high temperature vacuum brazing technique. During the development process we could optimize the chemical processing parameters, brazing process parameters, jigs and fixtures for high temperature brazing and leak testing, etc. Finally the window is tested for low power rf performance using VNA. In this paper we would present the development of the said window in detail along with its mechanical, vacuum and rf performances.

  11. Development of multi-channel high power rectangular RF window for LHCD system employing high temperature vacuum brazing technique

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, P K; Ambulkar, K K; Parmar, P R; Virani, C G; Thakur, A L [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India); Joshi, L M; Nangru, S C, E-mail: pramod@ipr.res.i [Central Electronics Engineering Research Institute, Pilani, Rajasthan 333 031 (India)

    2010-02-01

    A 3.7 GHz., 120 kW (pulsed), lower hybrid current drive (LHCD) system is employed to drive non-inductive plasma current in ADITYA tokamak. The rf power is coupled to the plasma through grill antenna and is placed in vacuum environment. A vacuum break between the pressurized transmission line and the grill antenna is achieved with the help of a multi (eight) channel rectangular RF vacuum window. The phasing between adjacent channels of 8-channel window (arranged in two rows) is important for launching lower hybrid waves and each channel should have independent vacuum window so that phase information is retained. The geometrical parameter of the grill antenna, like periodicity (9mm), channel dimensions (cross sectional dimension of 76mm x 7mm), etc. is to be maintained. These design constraint demanded a development of a multi channel rectangular RF vacuum window. To handle rf losses and thermal effects, high temperature vacuum brazing techniques is desired. Based on the above requirements we have successfully developed a multi channel rectangular rf vacuum window employing high temperature vacuum brazing technique. During the development process we could optimize the chemical processing parameters, brazing process parameters, jigs and fixtures for high temperature brazing and leak testing, etc. Finally the window is tested for low power rf performance using VNA. In this paper we would present the development of the said window in detail along with its mechanical, vacuum and rf performances.

  12. A design of 30/20 GHz flight communications experiment for NASA. [satellite and earth segments for high data rate commercial service

    Science.gov (United States)

    Kawamoto, Y.

    1982-01-01

    The objective of the 30/20 GHz Flight Experiment System is to develop the required technology and to experiment with the communication technique for an operational communication satellite system. The system uses polarization, spatial, and frequency isolations to maximize the spectrum utilization. The key spacecraft technologies required for the concept are the scan beam antenna, the baseband processor, the IF switch matrix, TWTA, SSPA, and LNA. The spacecraft communication payload information will be telemetered and monitored closely so that these technologies and performances can be verified. Two types of services, a trunk service and a customer premise service, are demonstrated in the system. Many experiments associated with these services, such as synchronization, demand assignment, link control, and network control will be performed to provide important information on the operational aspect of the system.

  13. Use of the 37-38 GHz and 40-40.5 GHz Ka-bands for Deep Space Communications

    Science.gov (United States)

    Morabito, David; Hastrup, Rolf

    2004-01-01

    This paper covers a wide variety of issues associated with the implementation and use of these frequency bands for deep space communications. Performance issues, such as ground station pointing stability, ground antenna gain, antenna pattern, and propagation effects such as due to atmospheric, charged-particle and space loss at 37 GHz, will be addressed in comparison to the 32 GHz Ka-band deep space allocation. Issues with the use of and competition for this spectrum also will be covered. The state of the hardware developed (or proposed) for operating in this frequency band will be covered from the standpoint of the prospects for achieving higher data rates that could be accommodated in the available bandwidth. Hardware areas to be explored include modulators, digital-to-analog converters, filters, power amplifiers, receivers, and antennas. The potential users of the frequency band will be explored as well as their anticipated methods to achieve the potential high data rates and the implications of the competition for bandwidth.

  14. High-power terahertz optical pulse generation with a dual-wavelength harmonically mode-locked Yb:YAG laser

    International Nuclear Information System (INIS)

    Zhuang, W Z; Chang, M T; Su, K W; Huang, K F; Chen, Y F

    2013-01-01

    We report on high-power terahertz optical pulse generation with a dual-wavelength harmonically mode-locked Yb:YAG laser. A semiconductor saturable absorber mirror is developed to achieve synchronously mode-locked operation at two spectral bands centered at 1031.67 and 1049.42 nm with a pulse duration of 1.54 ps and a pulse repetition rate of 80.3 GHz. With a diamond heat spreader to improve the heat removal efficiency, the average output power can be up to 1.1 W at an absorbed pump power of 5.18 W. The autocorrelation traces reveal that the mode-locked pulse is modulated with a beat frequency of 4.92 THz and displays a modulation depth to be greater than 80%. (paper)

  15. High RF Power Production for CLIC

    CERN Document Server

    Syratchev, I; Adli, E; Taborelli, M

    2007-01-01

    The CLIC Power Extraction and Transfer Structure (PETS) is a passive microwave device in which bunches of the drive beam interact with the impedance of the periodically loaded waveguide and excite preferentially the synchronous mode. The RF power produced (several hundred MW) is collected at the downstream end of the structure by means of the Power Extractor and delivered to the main linac structure. The PETS geometry is a result of multiple compromises between beam stability and main linac RF power needs. Another requirement is to provide local RF power termination in case of accelerating structure failure (ON/OFF capability). Surface electric and magnetic fields, power extraction method, HOM damping, ON/OFF capability and fabrication technology were all evaluated to provide a reliable design

  16. High-power TM01 millimeter wave pulse sensor in circular waveguide

    International Nuclear Information System (INIS)

    Wang Guang-Qiang; Zhu Xiang-Qin; Chen Zai-Gao; Wang Xue-Feng; Zhang Li-Jun

    2015-01-01

    By investigating the interaction of an n-type silicon sample with the TM 01 mode millimeter wave in a circular waveguide, a viable high-power TM 01 millimeter wave sensor is proposed. Based on the hot electron effect, the silicon sample serving as a sensing element (SE) and appropriately mounted on the inner wall of the circular waveguide is devoted to the on-line measurement of a high-power millimeter wave pulse. A three-dimensional parallel finite-difference time-domain method is applied to simulate the wave propagation within the measuring structure. The transverse electric field distribution, the dependences of the frequency response of the voltage standing-wave ratio (VSWR) in the circular waveguide, and the average electric field amplitude within the SE on the electrophysical parameters of the SE are calculated and analyzed in the frequency range of 300–400 GHz. As a result, the optimal dimensions and specific resistance of the SE are obtained, which provide a VSWR of no more than 2.0, a relative sensitivity around 0.0046 kW −1 fluctuating within ± 17.3%, and a maximum enduring power of about 4.3 MW. (paper)

  17. Indoor Corridor Wideband Radio Propagation Measurements and Channel Models for 5G Millimeter Wave Wireless Communications at 19 GHz, 28 GHz, and 38 GHz Bands

    Directory of Open Access Journals (Sweden)

    Ahmed M. Al-samman

    2018-01-01

    Full Text Available This paper presents millimeter wave (mmWave measurements in an indoor environment. The high demands for the future applications in the 5G system require more capacity. In the microwave band below 6 GHz, most of the available bands are occupied; hence, the microwave band above 6 GHz and mmWave band can be used for the 5G system to cover the bandwidth required for all 5G applications. In this paper, the propagation characteristics at three different bands above 6 GHz (19, 28, and 38 GHz are investigated in an indoor corridor environment for line of sight (LOS and non-LOS (NLOS scenarios. Five different path loss models are studied for this environment, namely, close-in (CI free space path loss, floating-intercept (FI, frequency attenuation (FA path loss, alpha-beta-gamma (ABG, and close-in free space reference distance with frequency weighting (CIF models. Important statistical properties, such as power delay profile (PDP, root mean square (RMS delay spread, and azimuth angle spread, are obtained and compared for different bands. The results for the path loss model found that the path loss exponent (PLE and line slope values for all models are less than the free space path loss exponent of 2. The RMS delay spread for all bands is low for the LOS scenario, and only the directed path is contributed in some spatial locations. For the NLOS scenario, the angle of arrival (AOA is extensively investigated, and the results indicated that the channel propagation for 5G using high directional antenna should be used in the beamforming technique to receive the signal and collect all multipath components from different angles in a particular mobile location.

  18. Design of the all solid high-voltage power supply for a gyrotron body

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Yihua [School of Mathematics and Physics, University of South China, Hengyang, 421001 (China); Chen, Wenguang, E-mail: 430000485393@usc.edu.cn [School of Electrical Engineering, University of South China, Hengyang, 421001 (China); Hu, Bo [School of Electrical Engineering, University of South China, Hengyang, 421001 (China); Rao, Jun; Huang, Mei; Kang, Zihua; Feng, Kun [Southwestern Institute of Physics, Chengdu, 610041 (China); Huang, Jiaqi [School of Electrical Engineering, University of South China, Hengyang, 421001 (China)

    2017-04-15

    Highlights: • Completed design of all solid-state high-voltage power supply for gyrotron body on HL-2M ECRH. • Consist of 58 PSM modules and one BUCK module, controlled by DSP system. • Fabricated full voltage 35 kV, 200 mA BPS and tested in dummy load. • The BPS can operate in three modes: single pulse mode, multi-pulse modulation mode and the six-level preset mode. - Abstract: Gyrotron plays an important role in the research of electron cyclotron resonance heating (ECRH) on Tokomak. The high-frequency switched power supply technology and pulse step modulation (PSM) technology are used in the development of the all solid high-voltage body power supply (BPS) for 1 MW/105 GHz Gyrotron on ECRH system. Firstly, the basic structure of the BPS and its control system are introduced. Secondly, the software control algorithm of voltage stabilization and modulate method are developed. Finally, the design is verified by the experiments. The experimental results of the single pulse mode, the multi-pulse modulation mode and the six-level preset mode, are shown. The output voltage of the power supply can reach 35 kV and the current at about 200 mA, which are adjustable in the full range. The maximum modulation frequency can reach 1 kHz and the front edge of the pulse can be adjust from 0 to 3 ms and the accuracy of the output voltage is less than 100 V. The results show that the control method is feasible and can be applied to other high power microwave sources.

  19. Highly-stabilized power supply for synchrotron accelerators. High speed, low ripple power supply

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Kenji [Osaka Univ., Ibaraki (Japan). Research Center for Nuclear Physics; Kumada, Masayuki; Fukami, Kenji; Koseki, Shoichiro; Kubo, Hiroshi; Kanazawa, Toru

    1997-02-01

    In synchrotron accelerators, in order to utilize high energy beam effectively, those are operated by repeating acceleration and taking-out at short period. In order to accelerate by maintaining beam track stable, the tracking performance with the error less than 10{sup -3} in the follow-up of current is required for the power supply. Further, in order to maintain the intensity and uniformity of beam when it is taken out, very low ripple is required for output current. The power supply having such characteristics has been developed, and applied to the HIMAC and the SPring-8. As the examples of the application of synchrotrons, the accelerators for medical treatment and the generation of synchrotron radiation are described. As to the power supply for the deflection magnets and quadrupole magnets of synchrotron accelerators, the specifications of the main power supply, the method of reducing ripple, the method of improving tracking, and active filter control are reported. As to the test results, the measurement of current ripple and tracking error is shown. The lowering of ripple was enabled by common mode filter and the symmetrical connection of electromagnets, and high speed response was realized by the compensation for delay with active filter. (K.I.)

  20. Test of a High Power Target Design

    CERN Multimedia

    2002-01-01

    %IS343 :\\\\ \\\\ A high power tantalum disc-foil target (RIST) has been developed for the proposed radioactive beam facility, SIRIUS, at the Rutherford Appleton Laboratory. The yield and release characteristics of the RIST target design have been measured at ISOLDE. The results indicate that the yields are at least as good as the best ISOLDE roll-foil targets and that the release curves are significantly faster in most cases. Both targets use 20 -25 $\\mu$m thick foils, but in a different internal geometry.\\\\ \\\\Investigations have continued at ISOLDE with targets having different foil thickness and internal geometries in an attempt to understand the release mechanisms and in particular to maximise the yield of short lived isotopes. A theoretical model has been developed which fits the release curves and gives physical values of the diffusion constants.\\\\ \\\\The latest target is constructed from 2 $\\mu$m thick tantalum foils (mass only 10 mg) and shows very short release times. The yield of $^{11}$Li (half-life of ...

  1. The SPES High Power ISOL production target

    Science.gov (United States)

    Andrighetto, A.; Corradetti, S.; Ballan, M.; Borgna, F.; Manzolaro, M.; Scarpa, D.; Monetti, A.; Rossignoli, M.; Silingardi, R.; Mozzi, A.; Vivian, G.; Boratto, E.; De Ruvo, L.; Sattin, N.; Meneghetti, G.; Oboe, R.; Guerzoni, M.; Margotti, A.; Ferrari, M.; Zenoni, A.; Prete, G.

    2016-11-01

    SPES (Selective Production of Exotic Species) is a facility under construction at INFN-LNL (Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Legnaro), aimed to produce intense neutron-rich radioactive ion beams (RIBs). These will be obtained using the ISOL (Isotope Separation On-Line) method, bombarding a uranium carbide target with a proton beam of 40MeV energy and currents up to 200μA. The target configuration was designed to obtain a high number of fissions, up to 1013 per second, low power deposition and fast release of the produced isotopes. The exotic isotopes generated in the target are ionized, mass separated and re-accelerated by the ALPI superconducting LINAC at energies of 10AMeV and higher, for masses in the region of A = 130 amu , with an expected rate on the secondary target up to 109 particles per second. In this work, recent results on the R&D activities regarding the SPES RIB production target-ion source system are reported.

  2. High-power pure blue laser diodes

    Energy Technology Data Exchange (ETDEWEB)

    Ohta, M.; Ohizumi, Y.; Hoshina, Y.; Tanaka, T.; Yabuki, Y.; Goto, S.; Ikeda, M. [Development Center, Sony Shiroishi Semiconductor Inc., Miyagi (Japan); Funato, K. [Materials Laboratories, Sony Corporation, Kanagawa (Japan); Tomiya, S. [Materials Analysis Laboratory, Sony Corporation, Kanagawa (Japan)

    2007-06-15

    We successfully developed high-power and long-lived pure blue laser diodes (LDs) having an emission wavelength of 440-450 nm. The pure-blue LDs were grown by metalorganic chemical vapor deposition (MOCVD) on GaN substrates. The dislocation density was successfully reduced to {proportional_to}10{sup 6} cm{sup -2} by optimizing the MOCVD growth conditions and the active layer structure. The vertical layer structure was designed to have an absorption loss of 4.9 cm{sup -1} and an internal quantum efficiency of 91%. We also reduced the operating current density to 6 kA/cm{sup 2} under 750 mW continuous-wave operation at 35 C by optimizing the stripe width to 12 {mu}m and the cavity length to 2000 {mu}m. The half lifetimes in constant current mode are estimated to be longer than 10000 h. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Complete low power controller for high voltage power systems

    International Nuclear Information System (INIS)

    Sumner, R.; Blanar, G.

    1997-01-01

    The MHV100 is a custom CMOS integrated circuit, developed for the AMS experiment. It provides complete control for a single channel high voltage (HV) generator and integrates all the required digital communications, D to A and A to D converters, the analog feedback loop and output drivers. This chip has been designed for use in both distributed high voltage systems or for low cost single channel high voltage systems. The output voltage and current range is determined by the external components

  4. Wideband Circularly Polarized Printed Ring Slot Antenna for 5 GHz – 6 GHz

    Science.gov (United States)

    Nasrun Osman, Mohamed; Rahim, Mohamad Helmi A.; Jusoh, Muzammil; Sabapathy, Thennarasan; Rahim, Mohamad Kamal A.; Norlyana Azemi, Saidatul

    2018-03-01

    This paper presents the design of circularly polarized printed slot antenna operating at 5 – 6 GHz. The proposed antenna consists of L-shaped feedline on the top of structure and circular ring slot positioned at the ground plane underneath the substrate as a radiator. A radial and narrow slot in the ground plane provides coupling between the L-shaped feedline and circular ring slot. The circular polarization is realized by implementing the slits perturbation located diagonally to perturb the current flow on the slot structure. The antenna prototype is fabricated on FR4 substrate. The simulated and measured results are compared and analyzed to demonstrate the performance of the antenna. Good measured of simulated results are obtained at the targeted operating frequency. The simulated -10dB reflection coefficient bandwidths and axial ratio are 750 MHz and 165 MHz, respectively. The investigation on the affect of the important parameters towards the reflection coefficient and axial are also presented. The proposed antenna is highly potential to be used for wireless local area network (WLAN) and wireless power transfer (WPT).

  5. High-Altitude Wind Power Generation

    NARCIS (Netherlands)

    Fagiano, L.; Milanese, M.; Piga, D.

    2010-01-01

    Abstract—The paper presents the innovative technology of highaltitude wind power generation, indicated as Kitenergy, which exploits the automatic flight of tethered airfoils (e.g., power kites) to extract energy from wind blowing between 200 and 800 m above the ground. The key points of this

  6. Experimental measurements on a 100 GHz frequency tunable quasioptical gyrotron

    International Nuclear Information System (INIS)

    Alberti, S.; Tran, M.Q.; Hogge, J.P.; Tran, T.M.; Bondeson, A.; Muggli, P.; Perrenoud, A.; Joedicke, B.; Mathews, H.G.

    1990-01-01

    Experiments on a 100 GHz quasioptical (QO) gyrotron operating at the fundamental (ω=Ω ce ) are described. Powers larger than 90 kW at an efficiency of about 12% were achieved. Depending on the electron beam parameters, the frequency spectrum of the output can be either single moded or multimoded. One of the main advantages of the QO gyrotron over the conventional gyrotron is its continuous frequency tunability. Various techniques to tune the output frequency have been tested, such as changing the mirror separation, the beam voltage, or the main magnetic field. Within the limitations of the present setup, 5% tunability was achieved. The QO gyrotron designed for operation at the fundamental frequency exhibits simultaneous emission at 100 GHz (fundamental) and 200 GHz (second harmonic). For a beam current of 4 A, 20% of the total rf power is emitted at the second harmonic

  7. High-power narrow-linewidth quasi-CW diode-pumped TEM00 1064 nm Nd:YAG ring laser.

    Science.gov (United States)

    Liu, Yuan; Wang, Bao-shan; Xie, Shi-yong; Bo, Yong; Wang, Peng-yuan; Zuo, Jun-wei; Xu, Yi-ting; Xu, Jia-lin; Peng, Qin-jun; Cui, Da-fu; Xu, Zu-yan

    2012-04-01

    We demonstrated a high average power, narrow-linewidth, quasi-CW diode-pumped Nd:YAG 1064 nm laser with near-diffraction-limited beam quality. A symmetrical three-mirror ring cavity with unidirectional operation elements and an etalon was employed to realize the narrow-linewidth laser output. Two highly efficient laser modules and a 90° quartz rotator for birefringence compensation were used for the high output power. The maximum average output power of 62.5 W with the beam quality factor M(2) of 1.15 was achieved under a pump power of 216 W at a repetition rate of 500 Hz, corresponding to the optical-to-optical conversion efficiency of 28.9%. The linewidth of the laser at the maximum output power was measured to be less than 0.2 GHz.

  8. SiC for microwave power transistors

    Energy Technology Data Exchange (ETDEWEB)

    Sriram, S.; Siergiej, R.R.; Clarke, R.C.; Agarwal, A.K.; Brandt, C.D. [Northrop Grumman Sci. and Technol. Center, Pittsburgh, PA (United States)

    1997-07-16

    The advantages of SiC for high power, microwave devices are discussed. The design considerations, fabrication, and experimental results are described for SiC MESFETs and SITs. The highest reported f{sub max} for a 0.5 {mu}m MESFET using semi-insulating 4H-SiC is 42 GHz. These devices also showed a small signal gain of 5.1 dB at 20 GHz. Other 4H-SiC MESFETs have shown a power density of 3.3 W/mm at 850 MHz. The largest SiC power transistor reported is a 450 W SIT measured at 600 MHz. The power output density of this SIT is 2.5 times higher than that of comparable silicon devices. SITs have been designed to operate as high as 3.0 GHz, with a 3 cm periphery part delivering 38 W of output power. (orig.) 28 refs.

  9. A 380 V High Efficiency and High Power Density Switched-Capacitor Power Converter using Wide Band Gap Semiconductors

    DEFF Research Database (Denmark)

    Fan, Lin; Knott, Arnold; Jørgensen, Ivan Harald Holger

    2018-01-01

    . This paper presents such a high voltage low power switched-capacitor DC-DC converter with an input voltage upto 380 V (compatible with rectified European mains) and an output power experimentally validated up to 21.3 W. The wideband gap semiconductor devices of GaN switches and SiC diodes are combined...... to compose the proposed power stage. Their switching and loss characteristics are analyzed with transient waveforms and thermal images. Different isolated driving circuits are compared and a compact isolated halfbridge driving circuit is proposed. The full-load efficiencies of 98.3% and 97.6% are achieved......State-of-the-art switched-capacitor DC-DC power converters mainly focus on low voltage and/or high power applications. However, at high voltage and low power levels, new designs are anticipated to emerge and a power converter that has both high efficiency and high power density is highly desirable...

  10. Measurement of high-power microwave pulse under intense ...

    Indian Academy of Sciences (India)

    Abstract. KALI-1000 pulse power system has been used to generate single pulse nanosecond duration high-power microwaves (HPM) from a virtual cathode oscillator. (VIRCATOR) device. HPM power measurements were carried out using a transmitting– receiving system in the presence of intense high frequency (a few ...

  11. A study of parametric instability in a harmonic gyrotron: Designs of third harmonic gyrotrons at 94 GHz and 210 GHz

    International Nuclear Information System (INIS)

    Saraph, G.P.; Antonsen, T.M. Jr.; Nusinovich, G.S.; Levush, B.

    1995-01-01

    Mode competition can present a major hurdle in achieving stable, efficient operation of a gyrotron at the cyclotron harmonics. A type of mode interaction in which three modes at different cyclotron harmonics are parametrically coupled together is analyzed here. This coupling can lead to parametric excitation or suppression of a mode; cyclic mode hopping; or the coexistence of three modes. Simulation results are presented for the parametric instability involving modes at the fundamental, second harmonic, and third harmonic of the cyclotron frequency. It is shown that the parametric excitation can lead to stable, efficient operation of a high-power gyrotron at the third harmonic. Based on this phenomenon, two practical designs are presented here for the third harmonic operation at 94 and 210 GHz. copyright 1995 American Institute of Physics

  12. Arbitrary waveform modulated pulse EPR at 200 GHz

    Science.gov (United States)

    Kaminker, Ilia; Barnes, Ryan; Han, Songi

    2017-06-01

    We report here on the implementation of arbitrary waveform generation (AWG) capabilities at ∼200 GHz into an Electron Paramagnetic Resonance (EPR) and Dynamic Nuclear Polarization (DNP) instrument platform operating at 7 T. This is achieved with the integration of a 1 GHz, 2 channel, digital to analog converter (DAC) board that enables the generation of coherent arbitrary waveforms at Ku-band frequencies with 1 ns resolution into an existing architecture of a solid state amplifier multiplier chain (AMC). This allows for the generation of arbitrary phase- and amplitude-modulated waveforms at 200 GHz with >150 mW power. We find that the non-linearity of the AMC poses significant difficulties in generating amplitude-modulated pulses at 200 GHz. We demonstrate that in the power-limited regime of ω1 10 MHz) spin manipulation in incoherent (inversion), as well as coherent (echo formation) experiments. Highlights include the improvement by one order of magnitude in inversion bandwidth compared to that of conventional rectangular pulses, as well as a factor of two in improvement in the refocused echo intensity at 200 GHz.

  13. F-band, High-Efficiency GaN Power Amplifier for the Scanning Microwave Limb Sounder and SOFIA, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — QuinStar Technology proposes to develop a 4-watt Solid-State Power Amplifier (SSPA) operating at F-band (106-114 GHz) with a power-added efficiency (PAE) of greater...

  14. Numerical design and analysis of parasitic mode oscillations for 95 GHz gyrotron beam tunnel

    Science.gov (United States)

    Kumar, Nitin; Singh, Udaybir; Yadav, Vivek; Kumar, Anil; Sinha, A. K.

    2013-05-01

    The beam tunnel, equipped with the high lossy ceramics, is designed for 95 GHz gyrotron. The geometry of the beam tunnel is optimized considering the maximum RF absorption (ideally 100%) and the suppression of parasitic oscillations. The excitation of parasitic modes is a concerning problem for high frequency, high power gyrotrons. Considering the problem of parasitic mode excitation in beam tunnel, a detail analysis is performed for the suppression of these kinds of modes. Trajectory code EGUN and CST Microwave Studio are used for the simulations of electron beam trajectory and electromagnetic analysis, respectively.

  15. RF Behavior of Cylindrical Cavity Based 240 GHz, 1 MW Gyrotron for Future Tokamak System

    Science.gov (United States)

    Kumar, Nitin; Singh, Udaybir; Bera, Anirban; Sinha, A. K.

    2017-11-01

    In this paper, we present the RF behavior of conventional cylindrical interaction cavity for 240 GHz, 1 MW gyrotron for futuristic plasma fusion reactors. Very high-order TE mode is searched for this gyrotron to minimize the Ohmic wall loading at the interaction cavity. The mode selection process is carried out rigorously to analyze the mode competition and design feasibility. The cold cavity analysis and beam-wave interaction computation are carried out to finalize the cavity design. The detail parametric analyses for interaction cavity are performed in terms of mode stability, interaction efficiency and frequency. In addition, the design of triode type magnetron injection gun is also discussed. The electron beam parameters such as velocity ratio and velocity spread are optimized as per the requirement at interaction cavity. The design studies presented here confirm the realization of CW, 1 MW power at 240 GHz frequency at TE46,17 mode.

  16. Development of steady-state 2 MW, 170 GHz gyrotrons for ITER

    International Nuclear Information System (INIS)

    Piosczyk, B.; Arnold, A.; Thumm, M.; Dammertz, G.; Heidinger, R.; Illy, S.; Jin, J.; Koppenburg, K.; Leonhardt, W.; Neffe, G.; Rzesnicki, T.; Schmid, M.; Yang, X.; Alberti, S.; Chavan, R.; Fasel, D.; Goodman, T.; Henderson, M.; Hogge, J.P.; Tran, M.Q.; Yovchev, I.; Erckmann, V.; Laqua, H.P.; Michel, G.; Gantenbein, G.; Kasparek, W.; Mueller, G.; Schwoerer, K.; Bariou, D.; Beunas, A.; Giguet, E.; LeCloarec, G.; Legrand, F.; Lievin, C.; Dumbrajs, O.

    2005-01-01

    A prototype of a 1 MW, CW, 140 GHz conventional gyrotron for the W7-X stellarator in Greifswald/Germany has been tested successfully and the fabrication of series tubes started. In extended studies the feasibility for manufacturing a continuously operated high power coaxial cavity gyrotron has been demonstrated and all needed data for an industrial design has been obtained. Based on this results the fabrication of a first prototype of a 2 MW, CW, 170 GHz coaxial cavity gyrotron started recently in cooperation between European research institutions and European tube industry. The prototype tube is foreseen to be tested in 2006 at CRPP Lausanne where a suitable test facility is under construction. (author)

  17. Operational upgrades to the DIII-D 60 GHz electron cyclotron resonant heating system

    International Nuclear Information System (INIS)

    Harris, T.E.; Cary, W.P.

    1993-10-01

    One of the primary components of the DIII-D radio frequency (rf) program over the past seven years has been the 60 GHz electron cyclotron resonant heating (ECRH) system. The system now consists of eight units capable of operating and controlling eight Varian VGE-8006 60 GHz, 200 kW gyrotrons along with their associated waveguide components. This paper will discuss the operational upgrades and the overall system performance. Many modifications were instituted to enhance the system operation and performance. Modifications discussed in this paper include an improved gyrotron tube-fault response network, a computer controlled pulse-timing and sequencing system, and an improved high-voltage power supply control interface. The discussion on overall system performance will include operating techniques used to improve system operations and reliability. The techniques discussed apply to system start-up procedures, operating the system in a conditioning mode, and operating the system during DIII-D plasma operations

  18. High Performance Design of 100Gb/s DPSK Optical Transmitter

    DEFF Research Database (Denmark)

    Das, Bhagwan; Abdullah, M.F.L; Shah, Nor Shahihda Mohd

    2016-01-01

    and optical transmitter have taken plenty of time for transmitting signal. When proposed design is operated at 1 GHz, 5 GHz, 10 GHz and 20 GHz using time constraint technique, it is observed that among all these frequencies, at 10 GHz high performance output is achieved for designed optical transmitter....... This high performance design of optical transmitter has zero timing error, low timing score and high slack time due to synchronization between input data and clock frequency. It is also determined that 99% timing score is reduced in comparison with 1 GHz frequency that has high jitters, high timing error......, high time score and low slack time. The high performance design is realized without disturbing actual bandwidth, power consumption and other parameters of the design. The proposed high performance design of 100Gb/s optical transmitter can be used with existing optical communication system to develop...

  19. High quality, high efficiency welding technology for nuclear power plants

    International Nuclear Information System (INIS)

    Aoki, Shigeyuki; Nagura, Yasumi

    1996-01-01

    For nuclear power plants, it is required to ensure the safety under the high reliability and to attain the high rate of operation. In the manufacture and installation of the machinery and equipment, the welding techniques which become the basis exert large influence to them. For the purpose of improving joint performance and excluding human errors, welding heat input and the number of passes have been reduced, the automation of welding has been advanced, and at present, narrow gap arc welding and high energy density welding such as electron beam welding and laser welding have been put to practical use. Also in the welding of pipings, automatic gas metal arc welding is employed. As for the welding of main machinery and equipment, there are the welding of the joints that constitute pressure boundaries, the build-up welding on the internal surfaces of pressure vessels for separating primary water from them, and the sealing welding of heating tubes and tube plates in steam generators. These weldings are explained. The welding of pipings and the state of development and application of new welding methods are reported. (K.I.)

  20. High performance magnet power supply optimization

    International Nuclear Information System (INIS)

    Jackson, L.T.

    1975-01-01

    Three types of magnet power supply systems for the joint LBL-SLAC proposed accelerator PEP are discussed. The systems considered include a firing circuit and six-pulse controlled rectifier, transistor systems, and a chopper system. (U.S.)

  1. Controlled Compact High Voltage Power Lines

    Directory of Open Access Journals (Sweden)

    Postolati V.

    2016-04-01

    Full Text Available Nowadays modern overhead transmission lines (OHL constructions having several significant differences from conventional ones are being used in power grids more and more widely. Implementation of compact overhead lines equipped with FACTS devices, including phase angle regulator settings (compact controlled OHL, appears to be one of the most effective ways of power grid development. Compact controlled AC HV OHL represent a new generation of power transmission lines embodying recent advanced achievements in design solutions, including towers and insulation, together with interconnection schemes and control systems. Results of comprehensive research and development in relation to 110–500kV compact controlled power transmission lines together with theoretical basis, substantiation, and methodological approaches to their practical application are presented in the present paper.

  2. Advanced Capacitors for High-Power Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — As the consumer and industrial requirements for compact, high-power-density, electrical power systems grow substantially over the next decade; there will be a...

  3. Status of experiments at LLNL on high-power X-band microwave generators

    International Nuclear Information System (INIS)

    Houck, T.L.; Westenskow, G.A.

    1994-01-01

    The Microwave Source Facility at the Lawrence Livermore National Laboratory (LLNL) is studying the application of induction accelerator technology to high-power microwave generators suitable for linear collider power sources. The authors report on the results of two experiments, both using the Choppertron's 11.4 GHz modulator and a 5-MeV, 1-kA induction beam. The first experimental configuration has a single traveling wave output structure designed to produce in excess of 300 MW in a single fundamental waveguide. This output structure consists of 12 individual cells, the first two incorporating de-Q-ing circuits to dampen higher order resonant modes. The second experiment studies the feasibility of enhancing beam to microwave power conversion by accelerating a modulated beam with induction cells. Referred to as the ''Reacceleration Experiment,'' this experiment consists of three traveling-wave output structures designed to produce about 125 MW per output and two induction cells located between the outputs. Status of current and planned experiments are presented

  4. Advances in high-power rf amplifiers

    International Nuclear Information System (INIS)

    Tallerico, P.J.

    1979-01-01

    Several powerful accelerators and storage rings are being considered that will require tens or even hundreds of megawatts of continuous rf power. The economics of such large machines can be dictated by the cost and efficiency of the rf amplifiers. The overall design and performance of such narrow-band amplifiers, operating in the 50- to 1500-MHz region, are being theoretically studied as a function of frequency to determine the optimum rf amplifier output power, gain, efficiency, and dc power requirements. The state of the art for three types of amplifiers (gridded tubes, klystrons, and gyrocons) is considered and the development work necessary to improve each is discussed. The gyrocon is a new device, hence its various embodiments are discussed in detail. The Soviet designs are reviewed and the gyrocon's strengths and weaknesses are compared to other types of microwave amplifiers. The primary advantages of the gyrocon are the very large amount of power available from a single device and the excellent efficiency and stable operation. The klystron however, has much greater gain and is simpler mechanically. At very low frequencies, the small size of the gridded tube makes it the optimum choice for all but the most powerful systems

  5. Design and development of high voltage high power operational ...

    Indian Academy of Sciences (India)

    Applications of power operational amplifiers (opamps) are increasing day by day in the industry as they are used in audio amplifiers, Piezo transducer systems and the electron deflection systems. Power operational amplifiers have all the features of a general purpose opamp except the additional power handling capability.

  6. Atmospheric Propagation and Combining of High-Power Lasers

    Science.gov (United States)

    2015-09-08

    Brightness-scaling potential of actively phase- locked solid state laser arrays,” IEEE J. Sel. Topics Quantum Electron., vol. 13, no. 3, pp. 460–472, May...attempting to phase- lock high-power lasers, which is not encountered when phase- locking low-power lasers, for example mW power levels. Regardless, we...technology does not currently exist. This presents a challenging problem when attempting to phase- lock high-power lasers, which is not encountered when

  7. Welding with high power fiber lasers - A preliminary study

    International Nuclear Information System (INIS)

    Quintino, L.; Costa, A.; Miranda, R.; Yapp, D.; Kumar, V.; Kong, C.J.

    2007-01-01

    The new generation of high power fiber lasers presents several benefits for industrial purposes, namely high power with low beam divergence, flexible beam delivery, low maintenance costs, high efficiency and compact size. This paper presents a brief review of the development of high power lasers, and presents initial data on welding of API 5L: X100 pipeline steel with an 8 kW fiber laser. Weld bead geometry was evaluated and transition between conduction and deep penetration welding modes was investigated

  8. Gas spectroscopy system with 245 GHz transmitter and receiver in SiGe BiCMOS

    Science.gov (United States)

    Schmalz, Klaus; Rothbart, Nick; Borngräber, Johannes; Yilmaz, Selahattin Berk; Kissinger, Dietmar; Hübers, Heinz-Wilhelm

    2017-02-01

    The implementation of an integrated mm-wave transmitter (TX) and receiver (RX) in SiGe BiCMOS or CMOS technology offers a path towards a compact and low-cost system for gas spectroscopy. Previously, we have demonstrated TXs and RXs for spectroscopy at 238 -252 GHz and 495 - 497 GHz using external phase-locked loops (PLLs) with signal generators for the reference frequency ramps. Here, we present a more compact system by using two external fractional-N PLLs allowing frequency ramps for the TX and RX, and for TX with superimposed frequency shift keying (FSK) or reference frequency modulation realized by a direct digital synthesizer (DDS) or an arbitrary waveform generator. The 1.9 m folded gas absorption cell, the vacuum pumps, as well as the TX and RX are placed on a portable breadboard with dimensions of 75 cm x 45 cm. The system performance is evaluated by high-resolution absorption spectra of gaseous methanol at 13 Pa for 241 - 242 GHz. The 2f (second harmonic) content of the absorption spectrum of the methanol was obtained by detecting the IF power of RX using a diode power sensor connected to a lock-in amplifier. The reference frequency modulation reveals a higher SNR (signal-noise-ratio) of 98 within 32 s acquisition compared to 66 for FSK. The setup allows for jumping to preselected frequency regions according to the spectral signature thus reducing the acquisition time by up to one order of magnitude.

  9. Globally Stable Microresonator Turing Pattern Formation for Coherent High-Power THz Radiation On-Chip

    Science.gov (United States)

    Huang, Shu-Wei; Yang, Jinghui; Yang, Shang-Hua; Yu, Mingbin; Kwong, Dim-Lee; Zelevinsky, T.; Jarrahi, Mona; Wong, Chee Wei

    2017-10-01

    In nonlinear microresonators driven by continuous-wave (cw) lasers, Turing patterns have been studied in the formalism of the Lugiato-Lefever equation with emphasis on their high coherence and exceptional robustness against perturbations. Destabilization of Turing patterns and the transition to spatiotemporal chaos, however, limit the available energy carried in the Turing rolls and prevent further harvest of their high coherence and robustness to noise. Here, we report a novel scheme to circumvent such destabilization, by incorporating the effect of local mode hybridizations, and we attain globally stable Turing pattern formation in chip-scale nonlinear oscillators with significantly enlarged parameter space, achieving a record-high power-conversion efficiency of 45% and an elevated peak-to-valley contrast of 100. The stationary Turing pattern is discretely tunable across 430 GHz on a THz carrier, with a fractional frequency sideband nonuniformity measured at 7.3 ×10-14 . We demonstrate the simultaneous microwave and optical coherence of the Turing rolls at different evolution stages through ultrafast optical correlation techniques. The free-running Turing-roll coherence, 9 kHz in 200 ms and 160 kHz in 20 minutes, is transferred onto a plasmonic photomixer for one of the highest-power THz coherent generations at room temperature, with 1.1% optical-to-THz power conversion. Its long-term stability can be further improved by more than 2 orders of magnitude, reaching an Allan deviation of 6 ×10-10 at 100 s, with a simple computer-aided slow feedback control. The demonstrated on-chip coherent high-power Turing-THz system is promising to find applications in astrophysics, medical imaging, and wireless communications.

  10. Efficient Low-Voltage Operation of a CW Gyrotron Oscillator at 233 GHz.

    Science.gov (United States)

    Hornstein, Melissa K; Bajaj, Vikram S; Griffin, Robert G; Temkin, Richard J

    2007-02-01

    The gyrotron oscillator is a source of high average power millimeter-wave through terahertz radiation. In this paper, we report low beam power and high-efficiency operation of a tunable gyrotron oscillator at 233 GHz. The low-voltage operating mode provides a path to further miniaturization of the gyrotron through reduction in the size of the electron gun, power supply, collector, and cooling system, which will benefit industrial and scientific applications requiring portability. Detailed studies of low-voltage operation in the TE(2) (,) (3) (,) (1) mode reveal that the mode can be excited with less than 7 W of beam power at 3.5 kV. During CW operation with 3.5-kV beam voltage and 50-mA beam current, the gyrotron generates 12 W of RF power at 233.2 GHz. The EGUN electron optics code describes the low-voltage operation of the electron gun. Using gun-operating parameters derived from EGUN simulations, we show that a linear theory adequately predicts the low experimental starting currents.

  11. Design of 2.5 GHz broad bandwidth microwave bandpass filter at operating frequency of 10 GHz using HFSS

    Science.gov (United States)

    Jasim, S. E.; Jusoh, M. A.; Mahmud, S. N. S.; Zamani, A. H.

    2018-04-01

    Development of low losses, small size and broad bandwidth microwave bandpass filter operating at higher frequencies is an active area of research. This paper presents a new route used to design and simulate microwave bandpass filter using finite element modelling and realized broad bandwidth, low losses, small dimension microwave bandpass filter operating at 10 GHz frequency using return loss method. The filter circuit has been carried out using Computer Aid Design (CAD), Ansoft HFSS software and designed with four parallel couple line model and small dimension (10 × 10 mm2) using LaAlO3 substrate. The response of the microwave filter circuit showed high return loss -50 dB at operating frequency at 10.4 GHz and broad bandwidth of 2.5 GHz from 9.5 to 12 GHz. The results indicate the filter design and simulation using HFSS is reliable and have the opportunity to transfer from lab potential experiments to the industry.

  12. GHz nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Cross, T.A.; Drobny, G.; Trewhella, J.

    1994-12-01

    For the past dozen years, 500- and 600-MHz spectrometers have become available in many laboratories. The first 600-MHz NMR spectrometer (at Carnegie Mellon University) was commissioned more than 15 years ago and, until 1994, represented the highest field available for high-resolution NMR. This year, we have witnessed unprecedented progress in the development of very high field magnets for NMR spectroscopy, including the delivery of the first commercial 750-MHz NMR spectrometers. In addition, NMR signals have been obtained from 20-Tesla magnets (850 MHz for {sup 1}H`s) at both Los Alamos National Laboratory and Florida State University in the NHMFL (National High Magnetic Field Laboratory). These preliminary experiments have been performed in magnets with 100-ppm homogeneity, but a 20-Tesla magnet developed for the NHMFL will be brought to field this year with a projected homogeneity of 0.1 ppm over a 1-cm-diam spherical volume.

  13. A 2.4GHz ULP OOK single-chip transceiver for healthcare applications

    NARCIS (Netherlands)

    Vidojkovic, M.; Huang, X.; Harpe, P.J.A.; Rampu, S.; Zhou, C.; Huang, Li; Molengraft, van de J.; Imamura, K.; Büsze, B.; Bouwens, F.; Konijnenburg, M.; Santana, J.; Breeschoten, A.; Huisken, J.; Philips, K.; Dolmans, G.; Groot, de H.W.H.

    2011-01-01

    This paper describes an ultra-low power (ULP) single chip transceiver for wireless body area network (WBAN) applications. It supports on-off keying (OOK) modulation, and it operates in the 2.36–2.4 GHz medical BAN and 2.4–2.485 GHz ISM bands. It is implemented in 90 nm CMOS technology. The direct

  14. 2.4GHz energy harvesting for wireless sensor network

    NARCIS (Netherlands)

    Gao, H.; Baltus, P.G.M.; Mahmoudi, R.; Roermund, van A.H.M.

    2011-01-01

    This paper presents the analysis of the performance of charge pump, and the design strategy and efficiency optimization of 2.4GHz micro-power charge pump using 65nm CMOS technology. The model of the charge pump takes account of the threshold voltage variation, bulk modulation, and the major

  15. A 62GHz inductor-peaked rectifier with 7% efficiency

    NARCIS (Netherlands)

    Gao, H.; Matters - Kammerer, M.; Milosevic, D.; Roermund, van A.H.M.; Baltus, P.G.M.

    2013-01-01

    This paper presents the first 62 GHz fully onchip RF-DC rectifier in 65nm CMOS technology. The rectifier is the bottleneck in realizing on-chip wireless power receivers. In this paper, efficiency problems of the mm-wave rectifier are discussed and the inductor-peaked rectifier structure is proposed

  16. High power diode pumped solid state lasers

    International Nuclear Information System (INIS)

    Solarz, R.; Albrecht, G.; Beach, R.; Comaskey, B.

    1992-01-01

    Although operational for over twenty years, diode pumped solid state lasers have, for most of their existence, been limited to individual diodes pumping a tiny volume of active medium in an end pumped configuration. More recent years have witnessed the appearance of diode bars, packing around 100 diodes in a 1 cm bar which have enabled end and side pumped small solid state lasers at the few Watt level of output. This paper describes the subsequent development of how proper cooling and stacking of bars enables the fabrication of multi kill average power diode pump arrays with irradiances of 1 kw/cm peak and 250 W/cm 2 average pump power. Since typical conversion efficiencies from the diode light to the pumped laser output light are of order 30% or more, kW average power diode pumped solid state lasers now are possible

  17. Detailed spectra of high-power broadband microwave radiation from interactions of relativistic electron beams with weakly magnetized plasmas

    International Nuclear Information System (INIS)

    Kato, K.G.; Benford, G.; Tzach, D.

    1983-01-01

    Prodigious quantities of microwave energy distributed uniformly across a wide frequency band are observed when a relativistic electron beam (REB) penetrates a plasma. Typical measured values are 20 MW total for Δνapprox. =40 GHz with preliminary observations of bandwidths as large as 100 GHz. An intense annular pulsed REB (Iapprox. =128 kA; rapprox. =3 cm; Δrapprox. =1 cm; 50 nsec FWHM; γapprox. =3) is sent through an unmagnetized or weakly magnetized plasma column (n/sub plasma/approx.10 13 cm -3 ). Beam-to-plasma densities of 0.01 >ω/sub p/ and weak harmonic structure is wholly unanticipated from Langmuir scattering or soliton collapse models. A model of Compton-like boosting of ambient plasma waves by the beam electrons, with collateral emission of high-frequency photons, qualitatively explains these spectra. Power emerges largely in an angle approx.1/γ, as required by Compton mechanisms. As n/sub b//n/sub p/ falls, ω/sub p/-2ω/sub p/ structure and harmonic power ratios consistent with soliton collapse theories appear. With further reduction of n/sub b//n/sub p/ only the ω/sub p/ line persists

  18. High efficiency fourth-harmonic generation from nanosecond fiber master oscillator power amplifier

    Science.gov (United States)

    Mu, Xiaodong; Steinvurzel, Paul; Rose, Todd S.; Lotshaw, William T.; Beck, Steven M.; Clemmons, James H.

    2016-03-01

    We demonstrate high power, deep ultraviolet (DUV) conversion to 266 nm through frequency quadrupling of a nanosecond pulse width 1064 nm fiber master oscillator power amplifier (MOPA). The MOPA system uses an Yb-doped double-clad polarization-maintaining large mode area tapered fiber as the final gain stage to generate 0.5-mJ, 10 W, 1.7- ns single mode pulses at a repetition rate of 20 kHz with measured spectral bandwidth of 10.6 GHz (40 pm), and beam qualities of Mx 2=1.07 and My 2=1.03, respectively. Using LBO and BBO crystals for the second-harmonic generation (SHG) and fourth-harmonic generation (FHG), we have achieved 375 μJ (7.5 W) and 92.5 μJ (1.85 W) at wavelengths of 532 nm and 266 nm, respectively. To the best of our knowledge these are the highest narrowband infrared, green and UV pulse energies obtained to date from a fully spliced fiber amplifier. We also demonstrate high efficiency SHG and FHG with walk-off compensated (WOC) crystal pairs and tightly focused pump beam. An SHG efficiency of 75%, FHG efficiency of 47%, and an overall efficiency of 35% from 1064 nm to 266 nm are obtained.

  19. High power microwave transmission systems for electron cyclotron resonance plasma heating

    International Nuclear Information System (INIS)

    Vernon, R.J.

    1989-08-01

    This progress report is for the fourth year of a grant from the US Department of Energy for the design, development, and fabrication of ECRF transmission and mode conversion systems to transport microwave power from a gyrotron to a magnetically confined plasma. The development and testing of new and improved components for such systems and underlying theory, where necessary, is the focus of this project. Devising and improving component testing and diagnostic techniques is also an important part of this effort. During the last year, we developed a preliminary design for a Te 15,2 --TE 15, 1 mode converter for the MIT 150 GHz gyrotron and considered its performance as the frequency and mode was step tuned. A preliminary design for a combined uptaper and TE 15,2 --TE 15,1 converter for possible use with the Varian 140 GHz gyrotron was also developed. Work was begun on a combined TE 15,n uptaper -- mode converter to produce a mode combination which would reduce microwave radiation into an azimuthal waveguide gap. Simple models for the radiation from TE 0n and TM 0n Vlasov launcher baffles were developed and compared with measurements which were taken in our radiation pattern measurement facility. Work began on testing possible methods for generating high azimuthal index rotating modes. Work on the further refinement of the method of mode content determination from open-end radiation pattern measurement was carried out. An investigation of the Wiener-Hopf method for obtaining open- end radiation patterns produced improved radiation patterns for the TE 0n modes in a circular waveguide. 15 refs., 15 figs

  20. New high power CW klystrons at TED

    CERN Document Server

    Beunas, A; Marchesin, R

    2003-01-01

    Thales Electron Devices (TED) has been awarded a contract by CERN to develop and produce 20 units of the klystrons needed to feed the Large Hadrons Collider (LHC). Each of these delivers 300 kW of CW RF power at 400 MHz. Three klystrons have been delivered to CERN up to now.

  1. Rectenna Technology Program: Ultra light 2.45 GHz rectenna 20 GHz rectenna

    Science.gov (United States)

    Brown, William C.

    1987-01-01

    The program had two general objectives. The first objective was to develop the two plane rectenna format for space application at 2.45 GHz. The resultant foreplane was a thin-film, etched-circuit format fabricated from a laminate composed of 2 mil Kapton F sandwiched between sheets of 1 oz copper. The thin-film foreplane contains half wave dipoles, filter circuits, rectifying Schottky diode, and dc bussing lead. It weighs 160 grams per square meter. Efficiency and dc power output density were measured at 85% and 1 kw/sq m, respectively. Special testing techniques to measure temperature of circuit and diode without perturbing microwave operation using the fluoroptic thermometer were developed. A second objective was to investigate rectenna technology for use at 20 GHz and higher frequencies. Several fabrication formats including the thin-film scaled from 2.45 GHz, ceramic substrate and silk-screening, and monolithic were investigated, with the conclusion that the monolithic approach was the best. A preliminary design of the monolithic rectenna structure and the integrated Schottky diode were made.

  2. High-voltage, high-power architecture considerations

    International Nuclear Information System (INIS)

    Moser, R.L.

    1985-01-01

    Three basic EPS architectures, direct energy transfer, peak-power tracking, and a potential EPS architecture for a nuclear reactor are described and compared. Considerations for the power source and energy storage are discussed. Factors to be considered in selecting the operating voltage are pointed out. Other EPS architecture considerations are autonomy, solar array degrees of freedom, and EPS modularity. It was concluded that selection of the power source and energy storage has major impacts on the spacecraft architecture and mass

  3. Modelling aluminium wire bond reliability in high power OMP devices

    NARCIS (Netherlands)

    Kregting, R.; Yuan, C.A.; Xiao, A.; Bruijn, F. de

    2011-01-01

    In a RF power application such as the OMP, the wires are subjected to high current (because of the high power) and high temperature (because of the heat from IC and joule-heating from the wire itself). Moreover, the wire shape is essential to the RF performance. Hence, the aluminium wire is

  4. GaN-based High Power High Frequency Wide Range LLC Resonant Converter, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — SET Group will design, build and demonstrate a Gallium Nitride (GaN) based High Power High Frequency Wide Range LLC Resonant Converter capable of handling high power...

  5. Third harmonic generation of high power far infrared radiation in semiconductors

    International Nuclear Information System (INIS)

    Urban, M.

    1996-04-01

    In this work we investigated the third harmonic generation of high power infrared radiation in doped semiconductors with emphasis on the conversion efficiency. The third harmonic generation effect is based on the nonlinear response of the conduction band electrons in the semiconductor with respect to the electric field of the incident electromagnetic wave. Because this work is directed towards a proposed application in fusion plasma diagnostics, the experimental requirements for the radiation source at the fundamental frequency are roughly given as follows: a wavelength of the radiation at the fundamental frequency in the order of 1 mm and an incident power greater than 1 MW. The most important experiments of this work were performed using the high power far infrared laser of the CRPP. With this laser a new laser line was discovered, which fits exactly the source specifications given above: the wavelength is 676 μm and the maximum power is up to 2 MW. Additional experiments were carried out using a 496 μm laser and a 140 GHz (2.1 mm) gyrotron. The main experimental progress with respect to previous work in this field is, in addition to the use of a very high power laser, the possibility of an absolute calibration of the detectors for the far infrared radiation and the availability of a new type of detector with a very fast response. This detector made it possible to measure the power at the fundamental as well as the third harmonic frequency with full temporal resolution of the fluctuations during the laser pulse. Therefore the power dependence of the third harmonic generation efficiency could be measured directly. The materials investigated were InSb as an example of a narrow gap semiconductor and Si as standard material. The main results are: narrow gap semiconductors indeed have a highly nonlinear electronic response, but the narrow band gap leads at the same time to a low power threshold for internal breakdown, which is due to impact ionization. (author) figs

  6. Los Alamos high-power proton linac designs

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, G.P. [Los Alamos National Laboratory, NM (United States)

    1995-10-01

    Medium-energy high-power proton linear accelerators have been studied at Los Alamos as drivers for spallation neutron applications requiring large amounts of beam power. Reference designs for such accelerators are discussed, important design factors are reviewed, and issues and concern specific to this unprecedented power regime are discussed.

  7. Performance of a high efficiency high power UHF klystron

    International Nuclear Information System (INIS)

    Konrad, G.T.

    1977-03-01

    A 500 kW c-w klystron was designed for the PEP storage ring at SLAC. The tube operates at 353.2 MHz, 62 kV, a microperveance of 0.75, and a gain of approximately 50 dB. Stable operation is required for a VSWR as high as 2 : 1 at any phase angle. The design efficiency is 70%. To obtain this value of efficiency, a second harmonic cavity is used in order to produce a very tightly bunched beam in the output gap. At the present time it is planned to install 12 such klystrons in PEP. A tube with a reduced size collector was operated at 4% duty at 500 kW. An efficiency of 63% was observed. The same tube was operated up to 200 kW c-w for PEP accelerator cavity tests. A full-scale c-w tube reached 500 kW at 65 kV with an efficiency of 55%. In addition to power and phase measurements into a matched load, some data at various load mismatches are presented

  8. Temperature Stabilized Characterization of High Voltage Power Supplies

    CERN Document Server

    Krarup, Ole

    2017-01-01

    High precision measurements of the masses of nuclear ions in the ISOLTRAP experiment relies on an MR-ToF. A major source of noise and drift is the instability of the high voltage power supplies employed. Electrical noise and temperature changes can broaden peaks in time-of-flight spectra and shift the position of peaks between runs. In this report we investigate how the noise and drift of high-voltage power supplies can be characterized. Results indicate that analog power supplies generally have better relative stability than digitally controlled ones, and that the high temperature coefficients of all power supplies merit efforts to stabilize them.

  9. 125-GHz Microwave Signal Generation Employing an Integrated Pulse Shaper

    DEFF Research Database (Denmark)

    Liao, Shasha; Ding, Yunhong; Dong, Jianji

    2017-01-01

    We propose and experimentally demonstrate an on-chip pulse shaper for 125-GHz microwave waveform generation. The pulse shaper is implemented based on a silicon-on-insulator (SOI) platform that has a structure with eight-tap finite impulse response (FIR) and there is an amplitude modulator on each...... of the generated microwave waveforms is larger than 100 GHz, and it has wide bandwidth when changing the time delay of the adjacent taps and compactness, capability for integration with electronics and small power consumption are also its merits.......We propose and experimentally demonstrate an on-chip pulse shaper for 125-GHz microwave waveform generation. The pulse shaper is implemented based on a silicon-on-insulator (SOI) platform that has a structure with eight-tap finite impulse response (FIR) and there is an amplitude modulator on each...

  10. Fusion blankets for high efficiency power cycles

    International Nuclear Information System (INIS)

    Powell, J.R.; Fillo, J.A.; Horn, F.L.; Lazareth, O.W.; Usher, J.L.

    1980-04-01

    Definitions are given of 10 generic blanket types and the specific blanket chosen to be analyzed in detail from each of the 10 types. Dimensions, compositions, energy depositions and breeding ratios (where applicable) are presented for each of the 10 designs. Ultimately, based largely on neutronics and thermal hyraulics results, breeding an nonbreeding blanket options are selected for further design analysis and integration with a suitable power conversion subsystem

  11. Power affects performance when the pressure is on: evidence for low-power threat and high-power lift.

    Science.gov (United States)

    Kang, Sonia K; Galinsky, Adam D; Kray, Laura J; Shirako, Aiwa

    2015-05-01

    The current research examines how power affects performance in pressure-filled contexts. We present low-power-threat and high-power-lift effects, whereby performance in high-stakes situations suffers or is enhanced depending on one's power; that is, the power inherent to a situational role can produce effects similar to stereotype threat and lift. Three negotiations experiments demonstrate that role-based power affects outcomes but only when the negotiation is diagnostic of ability and, therefore, pressure-filled. We link these outcomes conceptually to threat and lift effects by showing that (a) role power affects performance more strongly when the negotiation is diagnostic of ability and (b) underperformance disappears when the low-power negotiator has an opportunity to self-affirm. These results suggest that stereotype threat and lift effects may represent a more general phenomenon: When the stakes are raised high, relative power can act as either a toxic brew (stereotype/low-power threat) or a beneficial elixir (stereotype/high-power lift) for performance. © 2015 by the Society for Personality and Social Psychology, Inc.

  12. The theory of the quasi-optical grill: A lower hybrid wave launcher in the 4 - 10 GHz range for high field tokamaks

    International Nuclear Information System (INIS)

    Preinhaelter, J.; Vahala, L.; Vahala, G.

    1996-01-01

    Lower hybrid (LH) waves have been utilized for plasma heating and current drive in tokamaks. LH current drive has good efficiency in low to moderate plasma temperatures and is an excellent tool for attaining the reversed shear regions of much interest in advanced steady state tokamak scenarios. For high field tokamaks, the waveguides of the standard multifunction grills would become very narrow and the walls separating the waveguides would need to be very thin. As a result, the cooling of such structures becomes very difficult. Moreover, there are concerns that the classical grill launcher could not withstand the conditions at the reactor first wall. The Quasi-Optical Grill (QOG) was first proposed by Petelin ampersand Suvorov to overcome some of these difficulties. QOG attempts to couple the RF power to the plasma slow wave by means of the diffraction of the incident wave on an array of rods. However, these original calculations are based on certain idealized assumptions and lead to poor coupling to the plasma. Preinhaelter has suggested a new QOG in which the rods are placed in one oversized waveguide (open-quotes hyperguideclose quotes) and irradiated obliquely by the wave emerging as a higher order mode from an auxiliary oversized waveguide. The confining walls are now an intrinsic part of the structure and thus one avoids the need for mirrors and the introduction of open-quote point-like close-quote structures. This new QOG is compact - with several orders of magnitude less construction elements than the classical LH launcher - and the problem of wave diffraction can be readily solved using the full wave method. Here we consider the optimization of a large scale QOG at a given frequency. The irradiation of either a single row or double set of rows of rods are considered as well as their optimal separation. One can achieve transmissivity and directivity comparable to those of the multifunction grill. Design of a QOG for TORE-SUPRA will also be discussed

  13. A Dynamic Programming based method for optimizing power system restoration with high wind power penetration

    DEFF Research Database (Denmark)

    Hu, Rui; Hu, Weihao; Li, Pengfei

    2016-01-01

    and relatively low cost. Thus, many countries are increasing the wind power penetration in their power system step by step, such as Denmark, Spain and Germany. The incremental wind power penetration brings a lot of new issues in operation and programming. The power system sometimes will operate close to its...... stable limits. Once the blackout happens, a well-designed restoration strategy is significant. This paper focuses on how to ameliorate the power system restoration procedures to adapt the high wind power penetration and how to take full advantages of the wind power plants during the restoration....... In this paper, the possibility to exploit the stochastic wind power during restoration was discussed, and a Dynamic Programming (DP) method was proposed to make wind power contribute in the restoration rationally as far as possible. In this paper, the method is tested and verified by a modified IEEE 30 Buses...

  14. High-frequency high-voltage high-power DC-to-DC converters

    Science.gov (United States)

    Wilson, T. G.; Owen, H. A.; Wilson, P. M.

    1982-09-01

    A simple analysis of the current and voltage waveshapes associated with the power transistor and the power diode in an example current-or-voltage step-up (buck-boost) converter is presented. The purpose of the analysis is to provide an overview of the problems and design trade-offs which must be addressed as high-power high-voltage converters are operated at switching frequencies in the range of 100 kHz and beyond. Although the analysis focuses on the current-or-voltage step-up converter as the vehicle for discussion, the basic principles presented are applicable to other converter topologies as well.

  15. Utilization of a Vircator to drive a High Power Relativistic Klystron Amplifier

    Science.gov (United States)

    Gardelle, J.; Bardy, J.; Cassany, B.; Desanlis, T.; Eyl, P.; Galtié, A.; Modin, P.; Voisin, L.; Balleyguier, P.; Gouard, P.; Donohue, J.

    2002-11-01

    At CESTA, we have been producing electron beams for some fifteen years by using induction accelerators and pulse diodes. First we had performed Frre-Electron Lasers experiments and we are currently studying the production of High-Power microwaves in the S-band. Among the possible sources we have chosen to perform Relativistic Klystron (RK) experiments with a pulse diode capable of generating a 700kV, 15 kA, 100 ns annular electron beam. In an amplifier configuration, we are testing the idea of using a Vircator as the driver for the first cavity of the klystron. This Vircator uses a simple electrical generator (Marx capacitor bank) which operates in the S-band in the GW class. By reducing the power level to about 100 MW, a 200 ns reliable and reproducible input driver pulse is obtained. First, we present the results of a preliminary experiment for which a coaxial cavity has been built in order to be fed by the Vircator emission at 2.45 GHz. Secondly, we give the experimental results in an oscillator configuration which corresponds to the fisrt step of our RK studies. Comparisons with the results of numerical simulations performed with MAGIC and MAFIA will be given for both experiments.

  16. Proposed high voltage power supply for the ITER relevant lower hybrid current drive system

    International Nuclear Information System (INIS)

    Sharma, P.K.; Kazarian, F.; Garibaldi, P.; Gassman, T.; Artaud, J.F.; Bae, Y.S.; Belo, J.; Berger-By, G.; Bernard, J.M.; Cara, Ph.; Cardinali, A.; Castaldo, C.; Ceccuzzi, S.; Cesario, R.; Decker, J.; Delpech, L.; Ekedahl, A.; Garcia, J.; Goniche, M.; Guilhem, D.

    2011-01-01

    In the framework of the EFDA task HCD-08-03-01, the ITER lower hybrid current drive (LHCD) system design has been reviewed. The system aims to generate 24 MW of RF power at 5 GHz, of which 20 MW would be coupled to the plasmas. The present state of the art does not allow envisaging a unitary output of the klystrons exceeding 500 kW, so the project is based on 48 klystron units, leaving some margin when the transmission lines losses are taken into account. A high voltage power supply (HVPS), required to operate the klystrons, is proposed. A single HVPS would be used to feed and operate four klystrons in parallel configuration. Based on the above considerations, it is proposed to design and develop twelve HVPS, based on pulse step modulator (PSM) technology, each rated for 90 kV/90 A. This paper describes in details, the typical electrical requirements and the conceptual design of the proposed HVPS for the ITER LHCD system.

  17. Feasibility study of the EU home team on a 170 GHz 1 MW CW gyrotron for ECH on ITER

    International Nuclear Information System (INIS)

    Iatrou, C.T.; Kern, S.; Thumm, M.; Moebius, A.; Nickel, H.U.; Horajitra, P.; Wien, A.; Tran, T.M.; Bon Mardion, G.; Pain, M.; Tonon, G.

    1995-03-01

    The gyrotron system for ECH and burn control on ITER requires at least 50 MW of RF power at frequencies near 170 GHz operating in CW. To meet these requirements, high efficiency gyrotron tubes with ≥1 MW power output capability are necessary, as well as simple coupling to either a quasi-optical or waveguide transmission line. The paper reports the feasibility study on the design of an ITER-relevant gyrotron oscillator at 170 GHz, 1 MW CW employing a diode electron gun, an advanced internal quasi-optical converter, a cryogenically cooled single disk sapphire window, and a depressed potential collector. The operating mode selection and the cavity design is a compromise between many design constraints. (author) 18 figs., 6 tabs., 21 refs

  18. Validation of the superconducting 3.9 GHz cavity package for the European X-ray Free Electron Laser

    Science.gov (United States)

    Maiano, C. G.; Branlard, J.; Hüning, M.; Jensch, K.; Kostin, D.; Matheisen, A.; Möller, W.-D.; Sulimov, A.; Vogel, E.; Bosotti, A.; Chen, J. F.; Moretti, M.; Paparella, R.; Pierini, P.; Sertore, D.

    2017-04-01

    A full test of the cavity package concept under realistic operating condition was a necessary step before the assembly of the European XFEL (EXFEL) 3.9 GHz superconducting system and its installation in the accelerator. One cavity, equipped with magnetic shielding, power coupler and frequency tuner has been tested in a specially designed single cavity cryostat in one of the test benches of the DESY Accelerator Module Test Facility (AMTF). The cavity was operated at high pulsed power up to an accelerating field of 24 MV /m , above the quench accelerating field of 21 MV /m achieved during the continuous wave (CW) vertical qualification test and with a large margin with respect to the EXFEL maximum operating specification of 15 MV /m for the 3.9 GHz system. All subsystems under test—coupler, tuner, waveguide tuners, low level radio-frequency (LLRF) system—were qualified to their design performances.

  19. Sexual aggression when power is new: Effects of acute high power on chronically low-power individuals.

    Science.gov (United States)

    Williams, Melissa J; Gruenfeld, Deborah H; Guillory, Lucia E

    2017-02-01

    Previous theorists have characterized sexually aggressive behavior as an expression of power, yet evidence that power causes sexual aggression is mixed. We hypothesize that power can indeed create opportunities for sexual aggression-but that it is those who chronically experience low power who will choose to exploit such opportunities. Here, low-power men placed in a high-power role showed the most hostility in response to a denied opportunity with an attractive woman (Studies 1 and 2). Chronically low-power men and women given acute power were the most likely to say they would inappropriately pursue an unrequited workplace attraction (Studies 3 and 4). Finally, having power over an attractive woman increased harassment behavior among men with chronic low, but not high, power (Study 5). People who see themselves as chronically denied power appear to have a stronger desire to feel powerful and are more likely to use sexual aggression toward that end. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  20. High performance magnet power supply optimization

    International Nuclear Information System (INIS)

    Jackson, L.T.

    1988-01-01

    The power supply system for the joint LBL--SLAC proposed accelerator PEP provides the opportunity to take a fresh look at the current techniques employed for controlling large amounts of dc power and the possibility of using a new one. A basic requirement of +- 100 ppM regulation is placed on the guide field of the bending magnets and quadrupoles placed around the 2200 meter circumference of the accelerator. The optimization questions to be answered by this paper are threefold: Can a firing circuit be designed to reduce the combined effects of the harmonics and line voltage combined effects of the harmonics and line voltage unbalance to less than 100 ppM in the magnet field. Given the ambiguity of the previous statement, is the addition of a transistor bank to a nominal SCR controlled system the way to go or should one opt for an SCR chopper system running at 1 KHz where multiple supplies are fed from one large dc bus and the cost--performance evaluation of the three possible systems