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Sample records for amplifier experiment wiggler

  1. A CHI wiggler ubitron amplifier experiment: Wiggler characterization

    Energy Technology Data Exchange (ETDEWEB)

    Taccetti, J.M.; Jackson, R.H.; Freund, H.P. [Naval Research Lab., Washington, DC (United States)] [and others

    1995-12-31

    A 35 GHz CHI (Coaxial Hybrid Iron) wiggler ubitron amplifier experiment is under construction at the Naval Research Laboratory. The CHI wiggler configuration has the potential of generating high wiggler magnetic fields at short periods with excellent beam focusing and transport properties. This makes it a desirable configuration for the generation of high power coherent radiation in relatively compact systems. The CHI wiggler consists of alternating rings of magnetic and non-magnetic materials concentric with a central rod of similar alternating design but shifted along the axis by half a period. Once inserted in a solenoidal magnetic field, the CHI structure deforms the axial field to create a radial field oscillating with the same periodicity as the rings. An annular electron beam is propagated through the coaxial gap where the oscillating radial field imparts an azimuthal wiggle motion. The principal goals of the experiment are to investigate the performance tradeoffs involved in the CHI configuration for high frequency amplifiers operating at low voltages with small wiggler periods. The nominal design parameters are a center frequency of 35 GHz, wiggler period of 0.75 cm, and beam voltage of approximately 150 kV. Calculations have shown an intrinsic (untapered) efficiency of {approximately} 7% when operating at 6.3 kG axial field (wiggler field, B{sub w}{approximately}1270 G). The calculated gain was 36 dB, saturating at a distance of 46 cm. These parameters yield an instantaneous amplifier bandwidth of {approximately} 25%. There appears to be room for further improvement in efficiency, a matter which will be scrutinized more closely in the final design. A prototype CHI wiggler is presently being fabricated for use in conjunction with an existing 30 kG superconducting solenoid. The performance properties of the prototype will be characterized and compared with linear and non-linear calculations.

  2. Enhanced IFEL Experiment Using a Novel Wiggler.

    Science.gov (United States)

    Parsa, Z.; Marshall, T.

    1997-05-01

    In the conventional Inverse Free Electron Laser (IFEL), electron acceleration is done via the interaction of an intense laser beam and a wiggler, with a sinusoidal field pattern [ref: ATF IFEL Phys Rev Lett 77 2690 (1996)]. We have studied the effect on IFEL performance using a wiggler that creates a nearly square-wave periodic field pattern. A novel numerical technique is described which models this wiggler. We find stable orbits and an improvement in IFEL accelerating gradient, and as a result a gain in energy by as much as two times (equivalent to four times the laser power [ref: Z. Parsa, ITP/BNL-Report, 96; Z. Parsa, M. Pato, to be published], when compared with the conventional IFEL with a sinusoidal wiggler. In an experiment, the magnetic field can be synthesized by running a conventional ferromagnetic element wiggler into saturation. We have proposed such an experiment for Brookhaven - ATF.

  3. {open_quotes}Optical guiding{close_quotes} limits on extraction efficiencies of single-pass, tapered wiggler amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Fawley, W.M. [Lawrence Berkeley Lab., CA (United States)

    1995-12-31

    Single-pass, tapered wiggler amplifiers have an attractive feature of being able, in theory at least, of extracting a large portion of the electron beam energy into light. In circumstances where an optical FEL`s wiggler length is significantly longer than the Rayleigh length Z{sub R} corresponding to the electron beam radius, diffraction losses must be controlled via the phenomenon of {open_quotes}optical guiding{close_quotes}. Since the strength of the guiding depends upon the effective refractive index {eta}{sub r} exceeding one, and since ({eta}{sub r}-1) is inversely proportional to the optical electric field, there is a natural {open_quotes}limiting{close_quotes} mechanism to the on-axis field strength and thus the rate at which energy may be extracted from the electron beam. In particular, the extraction efficiency for a prebunched beam asymptotically grows linearly with z rather than quadratically. We present analytical and numerical simulation results concerning this behavior and discuss its applicability to various FEL designs including oscillator/amplifier-radiator configurations.

  4. Design and application of coaxial wigglers in free-electron lasers

    Science.gov (United States)

    Jackson, Robert H.; Blank, Monica; Freund, Henry P.; Pershing, Dean E.; Taccetti, J. M.

    1995-09-01

    The Naval Research Laboratory is investigating innovative magnetic wigglers to reduce beam energy requirements for millimeter wave FELs and to enhance the gain and efficiency. Recent work has focused on coaxial designs. The advantages of this are twofold. First, annular configurations are advantageous for propagating high current beams. The annular geometry permits use of the central structure to enhance the wiggler field, hence, allowing shorter wiggler periods. One such wiggler is referred to as the Coaxial Hybrid Iron (CHI) wiggler, and employs a solenoid enclosing periodic arrays of ferromagnetic and nonferromagnetic material arranged as an outer ring and an inner rod. A second wiggler uses both outer and inner bifilar helical current windings. Both wiggler designs result in substantial enhancements in the wiggler field experienced by the electron beam as compared with the fields in the absence of the central structure. A prototype CHI wiggler is discussed along with a 35 GHz amplifier experiment which is under construction. Preliminary performance calculations for a two helix wiggler system are discussed. This will include both orbit theory and a fully 3D nonlinear simulation of the interaction.

  5. Helical magnetized wiggler for synchrotron radiation laser

    CERN Document Server

    Wang Mei; Hirshfield, J L

    1999-01-01

    A helical magnetized iron wiggler has been built for a novel infrared synchrotron radiation laser (SRL) experiment. The wiggler consists of four periods of helical iron structure immersed in a solenoid field. This wiggler is to impart transverse velocity to a prebunched 6 MeV electron beam, and thus to obtain a desired high orbit pitch ratio for the SRL. Field tapering at beam entrance is considered and tested on a similar wiggler. Analytic and simulated characteristics of wigglers of this type are discussed and the performance of the fabricated wigglers is demonstrated experimentally. A 4.7 kG peak field was measured for a 6.4 mm air gap and a 5.4 cm wiggler period at a 20 kG solenoid field. The measured helical fields compare favorably with the analytical solution. This type of helical iron wigglers has the potential to be scaled to small periods with strong field amplitude.

  6. Operational Amplifier Experiments for the Chemistry Laboratory.

    Science.gov (United States)

    Braun, Robert D.

    1996-01-01

    Provides details of experiments that deal with the use of operational amplifiers and are part of a course in instrumental analysis. These experiments are performed after the completion of a set of electricity and electronics experiments. (DDR)

  7. Brightness of synchrotron radiation from wigglers

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca, E-mail: gianluca.geloni@xfel.eu [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2016-01-21

    According to the literature, while calculating the brightness of synchrotron radiation from wigglers, one needs to account for the so-called ‘depth-of-field’ effects. In fact, the particle beam cross-section varies along the wiggler. It is usually stated that the effective photon source size increases accordingly, while the brightness is reduced. Here we claim that this is a misconception originating from an analysis of the wiggler source based on geometrical arguments, regarded as almost self-evident. According to electrodynamics, depth-of-field effects do not exist: we demonstrate this statement both theoretically and numerically, using a well-known first-principle computer code. This fact shows that under the usually accepted approximations, the description of the wiggler brightness turns out to be inconsistent even qualitatively. Therefore, there is a need for a well-defined procedure for computing the brightness from a wiggler source. We accomplish this task based on the use of a Wigner function formalism. We exemplify this formalism in simple limiting cases. We consider the problem of the calculation of the wiggler source size by means of numerical simulations alone, which play the same role of an experiment. We report a significant numerical disagreement between exact calculations and approximations currently used in the literature.

  8. Brightness of synchrotron radiation from wigglers

    Science.gov (United States)

    Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

    2016-01-01

    According to the literature, while calculating the brightness of synchrotron radiation from wigglers, one needs to account for the so-called 'depth-of-field' effects. In fact, the particle beam cross-section varies along the wiggler. It is usually stated that the effective photon source size increases accordingly, while the brightness is reduced. Here we claim that this is a misconception originating from an analysis of the wiggler source based on geometrical arguments, regarded as almost self-evident. According to electrodynamics, depth-of-field effects do not exist: we demonstrate this statement both theoretically and numerically, using a well-known first-principle computer code. This fact shows that under the usually accepted approximations, the description of the wiggler brightness turns out to be inconsistent even qualitatively. Therefore, there is a need for a well-defined procedure for computing the brightness from a wiggler source. We accomplish this task based on the use of a Wigner function formalism. We exemplify this formalism in simple limiting cases. We consider the problem of the calculation of the wiggler source size by means of numerical simulations alone, which play the same role of an experiment. We report a significant numerical disagreement between exact calculations and approximations currently used in the literature.

  9. Brightness of synchrotron radiation from wigglers

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2014-12-15

    According to literature, while calculating the brightness of synchrotron radiation from wigglers, one needs to account for the so called 'depth-of-field' effects. In fact, the particle beam cross section varies along the wiggler. It is usually stated that the effective photon source size increases accordingly, while the brightness is reduced. Here we claim that this is a misconception originating from an analysis of the wiggler source based on geometrical arguments, regarded as almost self-evident. According to electrodynamics, depth-of-field effects do not exist: we demonstrate this statement both theoretically and numerically, using a well-known first-principle computer code. This fact shows that under the usually accepted approximations, the description of the wiggler brightness turns out to be inconsistent even qualitatively. Therefore, there is a need for a well-defined procedure for computing the brightness from a wiggler source. We accomplish this task based on the use of a Wigner function formalism. In the geometrical optics limit computations can be performed analytically. Within this limit, we restrict ourselves to the case of the beam size-dominated regime, which is typical for synchrotron radiation facilities in the X-ray wavelength range. We give a direct demonstration of the fact that the apparent horizontal source size is broadened in proportion to the beamline opening angle and to the length of the wiggler. While this effect is well-understood, a direct proof appears not to have been given elsewhere. We consider the problem of the calculation of the wiggler source size by means of numerical simulations alone, which play the same role of an experiment. We report a significant numerical disagreement between exact calculations and approximations currently used in literature.

  10. Tunability enhanced electromagnetic wiggler

    Science.gov (United States)

    Schlueter, Ross D.; Deis, Gary A.

    1992-01-01

    The invention discloses a wiggler used in synchrotron radiation sources and free electron lasers, where each pole is surrounded by at least two electromagnetic coils. The electromagnetic coils are energized with different amounts of current to provide a wide tunable range of the on-axis magnetic flux density, while preventing magnetic saturation of the poles.

  11. Ultrahigh vacuum diffractometer for grazing-angle x-ray standing-wave experiments at a vertical-wiggler source

    Science.gov (United States)

    Sakata, O.; Hashizume, H.

    1995-02-01

    An ultrahigh vacuum (UHV) diffractometer has been designed for studies of surface structures using the grazing-angle x-ray standing-wave method. The design is featured by a horizontal plane of diffraction for use at a vertical-wiggler source of synchrotron radiation. A sample is horizontally mounted in an UHV chamber (4×10-7 Pa) placed on crossed swivels, which control the glancing-incidence angle of x rays on the sample surface with a 50-μrad accuracy. The chamber accepts a sample from a transportation vessel under high vacuum. A beryllium window allows x-ray fluorescence to reach a semiconductor detector at short access. The whole assembly sits on a high-precision rotary table, regulating the sample Δθ angle with a reproducibility of better than 0.5 μrad required for control of the x-ray field profile. The system has been successfully applied to an accurate determination of the in-plane ordering of As atoms on a Si(111) surface with a 1×1 structure.

  12. Coaxial hybrid iron (CHI) wiggler

    Science.gov (United States)

    Jackson, Robert H.; Freund, Henry P.; Pershing, Dean E.; Taccetti, J. M.

    1993-11-01

    A magnetic wiggler design has been developed for applications in free-electron lasers which is scalable to small periods with high field amplitude, high beam current acceptance, and excellent transverse focusing and beam propagation properties. The Coaxial Hybrid Iron (CHI) wiggler design consists of a coaxial arrangement of alternating ferromagnetic and non- ferromagnetic rings with the central portion of the coax shifted by one half period. The entire arrangement is immersed in a solenoidal field which results in a cylindrically symmetric periodic field. A key advantage of this wiggler configuration is its capacity to handle very high beam currents with excellent focusing and transport properties. FEL configuration using the CHI wiggler design have the potential for high power, high frequency coherent generation in relatively compact systems. Analytic and simulated characteristics of the CHI wiggler are presented.

  13. Short wavelength FEL with helical micro-wiggler at FELI

    CERN Document Server

    Nakao, N; Goto, M; Ohigashi, N; Tsunawaki, Y; Moon, A; Nagai, A; Mima, K; Nakai, S; Yamanaka, C

    2000-01-01

    We are planning a short wavelength FEL experiment combining a micro-wiggler and an X-ray seed pulse. A micro-wiggler makes it possible to lase in the VUV to soft X-ray region using a low-energy electron beam. The development of the micro-wiggler is almost complete. With an intense X-ray seed pulse, quick start-up is expected making the wiggler length short. For the seed X-ray source we will use laser-produced Plasma. The validity of this concept was verified using a simulation code based on the SDE-method. With 10 kW X-ray power for seeding the saturation position is shortened to 5 m.

  14. Damping Undulators vs Damping Wigglers

    CERN Document Server

    Muchnoi, Nickolai

    2016-01-01

    Use of damping wigglers is a common technique for beam emittance reduction in the electron storage rings. The general approach to estimate damping effect is based on evaluation of several radiation integrals for a storage ring itself as well as for insertion devices. In this letter we show that a wiggler radiation integrals should be tweaked to account for the impact of lower harmonics of undulator radiation, which is an equivalent of Thomson scattering. Under certain conditions, these amendments play a decisive role in a formation of equilibrium emittance.

  15. Nuclear magnetic resonance experiments with dc SQUID amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Heaney, M.B. (California Univ., Berkeley, CA (USA). Dept. of Physics Lawrence Berkeley Lab., CA (USA))

    1990-11-01

    The development and fabrication of dc SQUIDs (Superconducting QUantum Interference Devices) with Nb/Al{sub 2}O{sub 3}/Nb Josephson junctions is described. A theory of the dc SQUID as a radio-frequency amplifier is presented, with an optimization strategy that accounts for the loading and noise contributions of the postamplifier and maximizes the signal-to-noise ratio of the total system. The high sensitivity of the dc SQUID is extended to high field NMR. A dc SQUID is used as a tuned radio-frequency amplifier to detect pulsed nuclear magnetic resonance at 32 MHz from a metal film in a 3.5 Tesla static field. A total system noise temperature of 11 K has been achieved, at a bath temperature of 4.2 K. The minimum number of nuclear Bohr magnetons observable from a free precession signal after a single pulse is about 2 {times} 10{sup 17} in a bandwidth of 25 kHz. In a separate experiment, a dc SQUID is used as a rf amplifier in a NQR experiment to observe a new resonance response mechanism. The net electric polarization of a NaClO{sub 3} crystal due to the precessing electric quadrupole moments of the Cl nuclei is detected at 30 MHz. The sensitivity of NMR and NQR spectrometers using dc SQUID amplifiers is compared to the sensitivity of spectrometers using conventional rf amplifiers. A SQUID-based spectrometer has a voltage sensitivity which is comparable to the best achieved by a FET-based spectrometer, at these temperatures and operating frequencies.

  16. Nuclear magnetic resonance experiments with DC SQUID amplifiers

    Science.gov (United States)

    Heaney, M. B.

    1990-11-01

    The development and fabrication of dc SQUIDs (Superconducting Quantum Interference Devices) with Nb/Al2O3/Nb Josephson junctions is described. A theory of the dc SQUID as a radio-frequency amplifier is presented, with an optimization strategy that accounts for the loading and noise contributions of the postamplifier and maximizes the signal-to-noise ratio of the total system. The high sensitivity of the dc SQUID is extended to high field NMR. A dc SQUID is used as a tuned radio-frequency amplifier to detect pulsed nuclear magnetic resonance at 32 MHz from a metal film in a 3.5 Tesla static field. A total system noise temperature of 11 K has been achieved, at a bath temperature of 4.2 K. The minimum number of nuclear Bohr magnetons observable from a free precession signal after a single pulse is about 2 x 10(exp 17) in a bandwidth of 25 kHz. In a separate experiment, a dc SQUID is used as a rf amplifier in a NQR experiment to observe a new resonance response mechanism. The net electric polarization of a NaClO3 crystal due to the precessing electric quadrupole moments of the Cl nuclei is detected at 30 MHz. The sensitivity of NMR and NQR spectrometers using dc SQUID amplifiers is compared to the sensitivity of spectrometers using conventional rf amplifiers. A SQUID-based spectrometer has a voltage sensitivity which is comparable to the best achieved by a FET-based spectrometer, at these temperatures and operating frequencies.

  17. Brightness of synchrotron radiation from wigglers

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni

    2014-01-01

    According to literature, while calculating the brightness of synchrotron radiation from wigglers, one needs to account for the so called `depth-of-field' effects. In fact, the particle beam cross section varies along the wiggler. It is usually stated that the effective photon source size increases accordingly, while the brightness is reduced. Here we claim that this is a misconception originating from an analysis of the wiggler source based on geometrical arguments, regarded as almost self-evident. According to electrodynamics, depth-of-field effects do not exist: we demonstrate this statement both theoretically and numerically, using a well-known first-principle computer code. This fact shows that under the usually accepted approximations, the description of the wiggler brightness turns out to be inconsistent even qualitatively. Therefore, there is a need for a well-defined procedure for computing the brightness from a wiggler source. We accomplish this task based on the use of a Wigner function formalism. I...

  18. Fast pulsed excitation wiggler or undulator

    Science.gov (United States)

    van Steenbergen, Arie

    1990-01-01

    A fast pulsed excitation, electromagnetic undulator or wiggler, employing geometrically alternating substacks of thin laminations of ferromagnetic material, together with a single turn current loop excitation of the composite assembly, of such shape and configuration that intense, spatially alternating, magnetic fields are generated; for use as a pulsed mode undulator or wiggler radiator, for use in a Free Electron Laser (FEL) type radiation source or, for use in an Inverse Free Electron Laser (IFEL) charged particle accelerator.

  19. Pulse propagation in the tapered wiggler

    Science.gov (United States)

    Al-Abawi, H.; McIver, J. K.; Moore, G. T.; Scully, M. O.

    Theory and preliminary numerical calculations are presented for coherent optical and electron pulse propagation in a free-electron laser with a tapered wiggler. Since only trapped electrons contribute significantly to the laser radiation, it is possible to define generalized 'slow' space-time coordinates in terms of which the electron pulse envelope may be considered constant. The theory is outlined first for the helical wiggler and then is developed for an arbitrary quasiperiodic wiggler, using a more rigorous 'multiple-scaling' approach. In the latter case a modified definition of the electron phase angle is required, and optical harmonic generation is predicted. The numerical calculations show that substantial energy extraction is achievable, but that the optical pulse rapidly breaks up into a series of spikes in the time domain. Surprisingly, the optical spectrum remains quite smooth in appearance.

  20. Harmonic generation with multiple wiggler schemes

    Energy Technology Data Exchange (ETDEWEB)

    Bonifacio, R.; De Salvo, L.; Pierini, P. [Universita degli Studi, Milano (Italy)

    1995-02-01

    In this paper the authors give a simple theoretical description of the basic physics of the single pass high gain free electron laser (FEL), describing in some detail the FEL bunching properties and the harmonic generation technique with a multiple-wiggler scheme or a high gain optical klystron configuration.

  1. Investigation on Satellite-borne High-power Solid-state Power Amplifier Technology and Experiment

    OpenAIRE

    Wu Xiao-po; Zhao Hai-yang; Xi Song-tao

    2014-01-01

    Based on the research and development efforts of satellite-borne lumped solid-state transmitters, the design of a satellite-borne high-power microwave amplifier module is introduced. Focusing on satellite-borne applications, aspects of the high-power density thermal design, multipactor proof design, EMC design and so on, which are critical technologies for a solid-state power amplifier, are discussed. Subsequently, experiments are used to verify the concept.

  2. Investigation on Satellite-borne High-power Solid-state Power Amplifier Technology and Experiment

    Directory of Open Access Journals (Sweden)

    Wu Xiao-po

    2014-06-01

    Full Text Available Based on the research and development efforts of satellite-borne lumped solid-state transmitters, the design of a satellite-borne high-power microwave amplifier module is introduced. Focusing on satellite-borne applications, aspects of the high-power density thermal design, multipactor proof design, EMC design and so on, which are critical technologies for a solid-state power amplifier, are discussed. Subsequently, experiments are used to verify the concept.

  3. Control and data acquisition systems for high field superconducting wigglers

    CERN Document Server

    Batrakov, A; Karpov, G; Kozak, V; Kuzin, M; Kuper, E; Mamkin, V; Mezentsev, N A; Repkov, V V; Selivanov, A; Shkaruba, V A

    2001-01-01

    This paper describes the control and DAQ system of superconducting wigglers with magnetic field range up to 10.3 T. The first version of the system controls a 7 T superconducting wiggler prepared for installation at Bessy-II (Germany). The second one controls a 10 T wiggler which is under testing now at the SPring-8 site (Japan). Both systems are based on VME apparatus. The set of specialized VME modules is elaborated to arrange wiggler power supply control, full time wiggler monitoring, and magnetic field high accuracy measurement and field stabilization. The software for the control of the wigglers is written in C language for VxWorks operation system for a Motorola-162 VME controller. The task initialization, stops and acquisition of the data can be done from the nearest personal computer (FTP host for VME), or from the remote system as well.

  4. Damping Wiggler Study at KEK-ATF

    CERN Document Server

    Naito, Takashi; Honda, Yosuke; Korostelev, Maxim S; Kubo, Kiyoshi; Kuriki, Masao; Kuroda, Shigeru; Muto, Toshiya; Nakamura, Norio; Ross, Marc; Sakai, Hiroshi; Terunuma, Nobuhiro; Urakawa, Junji; Zimmermann, Frank

    2005-01-01

    The effects by damping wiggler magnets have been studied at KEK-ATF. The damping ring of the KEK-ATF is a 1.3 GeV storage ring capable of producing ultra-low emittance electron beams. It is significant issue to realize fast damping in the damping ring. The tuning method with 4 sets of wiggler was investigated for the ultra-low emittance beam. The performance on the beam quality, which is related to the transverse (x and y) and the longitudinal (z and dp/p), has been measured by the SR monitor, the laser wire, the streak camera and the energy spread monitor at the extraction line. We report on the operation condition and the measurement results.

  5. Electron dynamics with radiation and nonlinear wigglers

    Energy Technology Data Exchange (ETDEWEB)

    Jowett, J.M.

    1986-06-01

    The physics of electron motion in storage rings is described by supplementing the Hamiltonian equations of motion with fluctuating radiation reaction forces to describe the effects of synchrotron radiation. This leads to a description of radiation damping and quantum diffusion in single-particle phase-space by means of Fokker-Planck equations. For practical purposes, most storage rings remain in the regime of linear damping and diffusion; this is discussed in some detail with examples, concentrating on longitudinal phase space. However special devices such as nonlinear wigglers may permit the new generation of very large rings to go beyond this into regimes of nonlinear damping. It is shown how a special combined-function wiggler can be used to modify the energy distribution and current profile of electron bunches.

  6. A CLIC Damping Wiggler Prototype at ANKA: Commissioning and Preparations for a Beam Dynamics Experimental Program

    CERN Document Server

    Bernhard, Axel; Casalbuoni, Sara; Ferracin, Paolo; Garcia Fajardo, Laura; Gerstl, Stefan; Gethmann, Julian; Grau, Andreas; Huttel, Erhard; Khrushchev, Sergey; Mezentsev, Nikolai; Müller, Anke-Susanne; Papaphilippou, Yannis; Saez de Jauregui, David; Schmickler, Hermann; Schoerling, Daniel; Shkaruba, Vitaliy; Smale, Nigel; Tsukanov, Valery; Zisopoulos, Panagiotis; Zolotarev, Konstantin

    2016-01-01

    In a collaboration between CERN, BINP and KIT a prototype of a superconducting damping wiggler for the CLIC damping rings has been installed at the ANKA synchrotron light source. On the one hand, the foreseen experimental program aims at validating the technical design of the wiggler, particularly the conduction cooling concept applied in its cryostat design, in a long-term study. On the other hand, the wiggler's influence on the beam dynamics particularly in the presence of collective effects is planned to be investigated. ANKA's low-alpha short-bunch operation mode will serve as a model system for these studies on collective effects. To simulate these effects and to make verifiable predictions an accurate model of the ANKA storage ring in low-alpha mode, including the insertion devices is under parallel development. This contribution reports on the first operational experience with the CLIC damping wiggler prototype in the ANKA storage ring and steps towards the planned advanced experimental program with th...

  7. Elliptical multipole wiggler beamlines at the advanced photon source

    Energy Technology Data Exchange (ETDEWEB)

    Beno, M.A. E-mail: beno@anl.gov; Kurtz, C.; Munkholm, A.; Ruett, U.; Engbretson, M.; Jennings, G.; Linton, J.; Knapp, G.S.; Montano, P.A

    2001-07-21

    The Basic Energy Sciences Synchrotron Radiation Center Collaborative Access Team has built three independent beamlines, which simultaneously utilize the X-ray radiation from an elliptical multipole wiggler, located at Sector 11 of the Advanced Photon Source. This insertion device produces circularly polarized X-rays on-axis and linearly polarized X-rays above and below the ring plane. The lower linearly polarized radiation is used in the monochromatic 11ID-D station for scattering and spectroscopy experiments in the 5-40 keV range. The on-axis circularly polarized photons are used for magnetic Compton scattering experiments in the 11ID-B station. The upper linearly polarized radiation is utilized by the high-energy diffraction station, 11ID-C. We report here on the beamline optics and experimental station equipment.

  8. Raman free-electron laser with a coaxial wiggler

    Science.gov (United States)

    Farokhi, B.; Maraghechi, B.; Willett, J. E.

    2000-10-01

    A one-dimensional theory of the stimulated Raman scattering mechanism for a coaxial free-electron laser (FEL) is developed. The beam-frame FEL dispersion relation and a formula for the lab-frame spatial growth rate are derived. A numerical study of the growth rate for the coaxial wiggler is made and compared with that for the helical wiggler. Except for a part of the group II orbits, the growth rate is found to be less than the helical wiggler. Relativistic effects due to the transverse oscillation of electrons in the wiggler field prevent the FEL operation from approaching magnetoresonance. In the absence of these relativistic mass effects, the calculations show a magnetoresonance associated with the first spatial harmonic and a much narrower resonance at the third spatial harmonic.

  9. Nonlinear analysis of wiggler-imperfections in free-electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Freund, H.P. [Naval Research Lab., Washington, DC (United States); Yu, L.H. [Brookhaven National Lab., Upton, NY (United States)

    1995-12-31

    We present an analysis of the effect of wiggler imperfections in FELs using a variety of techniques. Our basic intention is to compare wiggler averaged nonlinear simulations to determine the effect of various approximations on the estimates of gain degradation due to wiggler imperfections. The fundamental assumption in the wiggler-averaged formulations is that the electrons are described by a random walk model, and an analytic representation of the orbits is made. This is fundamentally different from the approach taken for the non-wiggler-averaged formulation in which the wiggler imperfections are specified at the outset, and the orbits are integrated using a field model that is consistent with the Maxwell equations. It has been conjectured on the basis of prior studies using the non-wiggler-averaged formalism that electrons follow a {open_quotes}meander line{close_quotes} through the wiggler governed by the specific imperfections; hence, the electrons behave more as a ball-in-groove than as a random walk. This conjecture is tested by comparison of the wiggler-averaged and non-wiggler-averaged simulations. In addition, two different wiggler models are employed in the non-wiggler-averaged simulation: one based upon a parabolic pole face wiggler which is not curl and divergence free in the presence of wiggler imperfections, and a second model in which the divergence and z-component of the curl vanish identically. This will gauge the effect of inconsistencies in the wiggler model on the estimation of the effect of the imperfections. Preliminary results indicate that the inconsistency introduced by the non-vanishing curl and divergence result in an overestimation of the effect of wiggler imperfections on the orbit. The wiggler-averaged simulation is based upon the TDA code, and the non-wiggler-averaged simulation is a variant of the ARACHNE and WIGGLIN codes called MEDUSA developed to treat short-wavelength Gauss-Hermite modes.

  10. X-ray Synchrotron Radiation in a Plasma Wiggler

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shuoquin; /UCLA /SLAC, SSRL

    2005-09-27

    A relativistic electron beam can radiate due to its betatron motion inside an ion channel. The ion channel is induced by the electron bunch as it propagates through an underdense plasma. In the theory section of this thesis the formation of the ion channel, the trajectories of beam electrons inside the ion channel, the radiation power and the radiation spectrum of the spontaneous emission are studied. The comparison between different plasma wiggler schemes is made. The difficulties in realizing stimulated emission as the beam traverses the ion channel are investigated, with particular emphasis on the bunching mechanism, which is important for the ion channel free electron laser. This thesis reports an experiment conducted at the Stanford Linear Accelerator Center (SLAC) to measure the betatron X-ray radiations for the first time. They first describe the construction and characterization of the lithium plasma source. In the experiment, the transverse oscillations of the SLAC 28.5 GeV electron beam traversing through a 1.4 meter long lithium plasma source are clearly seen. These oscillations lead to a quadratic density dependence of the spontaneously emitted betatron X-ray radiation. The divergence angle of the X-ray radiation is measured. The absolute photon yield and the spectral brightness at 14.2 KeV photon energy are estimated and seen to be in reasonable agreement with theory.

  11. High Heat-Load Slits for the PLS Multipole Wiggler

    CERN Document Server

    Gil, Kyehwan; Kim, Young-Chan; Lee, Heung-Soo; Wha Chung, Chin

    2005-01-01

    The HFMX (High Flux Macromolecular X-ray crystallography) beamline under commissioning at Pohang Accelerator Laboratory uses beam from a multipole wiggler for MAD experiment. Two horizontal and vertical slits relevant to high heat load are installed at its front-end. In order to treat high heat load and to reduce beam scattering, the horizontal slit has two glidcop blocks with 10° of vertical inclination and its tungsten blades defining beam size are bolted on backsides of both blocks. The blocks of the slit are adjusted on fixed slides by two actuating bars, respectively. Water through channels machined along the actuating bars cool down the heat load of both blocks. The vertical slit has the same structure as the horizontal slit except its installation direction and angle of vertical inclination. The installed slits show stable operation performance and no alignment for the blocks is required by virtue of a pair of blocks translating on slides. The cooling performance of two slits is also shown to ...

  12. AIDA: A 16-channel amplifier ASIC to read out the advanced implantation detector array for experiments in nuclear decay spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Braga, D. [STFC Rutherford Appleton Laboratory, Didcot, OX11 0QX (United Kingdom); Coleman-Smith, P. J. [STFC Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Davinson, T. [Dept. of Physics and Astronomy, Univ. of Edinburgh, Edinburgh EH9 3JZ (United Kingdom); Lazarus, I. H. [STFC Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Page, R. D. [Dept. of Physics, Univ. of Liverpool, Oliver Lodge Laboratory, Liverpool L69 7ZE (United Kingdom); Thomas, S. [STFC Rutherford Appleton Laboratory, Didcot, OX11 0QX (United Kingdom)

    2011-07-01

    We have designed a read-out ASIC for nuclear decay spectroscopy as part of the AIDA project - the Advanced Implantation Detector Array. AIDA will be installed in experiments at the Facility for Antiproton and Ion Research in GSI, Darmstadt. The AIDA ASIC will measure the signals when unstable nuclei are implanted into the detector, followed by the much smaller signals when the nuclei subsequently decay. Implant energies can be as high as 20 GeV; decay products need to be measured down to 25 keV within just a few microseconds of the initial implants. The ASIC uses two amplifiers per detector channel, one covering the 20 GeV dynamic range, the other selectable over a 20 MeV or 1 GeV range. The amplifiers are linked together by bypass transistors which are normally switched off. The arrival of a large signal causes saturation of the low-energy amplifier and a fluctuation of the input voltage, which activates the link to the high-energy amplifier. The bypass transistors switch on and the input charge is integrated by the high-energy amplifier. The signal is shaped and stored by a peak-hold, then read out on a multiplexed output. Control logic resets the amplifiers and bypass circuit, allowing the low-energy amplifier to measure the subsequent decay signal. We present simulations and test results, demonstrating the AIDA ASIC operation over a wide range of input signals. (authors)

  13. Preliminary design for a pierce wiggler beamstick and addendum

    Energy Technology Data Exchange (ETDEWEB)

    Pirkle, D.

    1988-05-01

    Lawrence Livermore National Laboratory is developing a fast tunable microwave source for operation at 250 GHz and 10kW peak output power. This report presents the preliminary design of a Pierce gun and solenoid magnet that will be compatible with a Pierce-wiggler electron beam formation system (beamstick). The beamstick will be an appropriate power source for a tunable gyro-BWO at 250 GHz. Figure 1 presents the major components of the Pierce-wiggler beamstick: the electron gun, solenoid, beam tunnel, wiggler, and vacuum valve. Figure 2 shows an artistic conception of how the beamstick will interface with the interaction magnet, modulator and gyro-BWO circuit at MIT. 15 figs.

  14. Linear Optics Compensation of the Superconducting Wiggler in HLS

    CERN Document Server

    Wang, Lin; Li, Wei-min; Xu, Hong-liang; Zhang, He

    2005-01-01

    Hefei Light Source is a dedicated VUV light source. A superconducting wiggler magnet with 6 Tesla magnetic field was installed on the storage ring to generate hard X-ray radiation. With the compensation of tune shift due to insertion device, beam was successfully stored, but the beam lifetime was decreased much. In order to cure the lifetime, a simple hard-edge model of the wiggler was constructed in lattice simulation code and the compensation scheme was extensively studied again. Calculation showed that it is difficulty to localize the strong focusing effects from wiggler magnet. Then, a new scheme was brought forward and experimental result showed that it can restore the beam lifetime largely. As the application of LOCO method in HLS, a new compensation scheme was calculated by response matrix fitting, and the experimental result also presented in this paper.

  15. A wiggler magnet for FEL low voltage operation

    Energy Technology Data Exchange (ETDEWEB)

    Al-Shamma`a, A.; Stuart, R.A.; Lucas, J.

    1995-12-31

    In low voltage FELs (ie, 200kV), operation is necessarily in the microwave frequency range for wiggler periods of the order of cms., so that a waveguide system is mandatory. Also, because of the relatively low velocity of the electron beam, the wiggle amplitude of the electron beam can be much larger than is normal for highly relativistic FELs. Both these factors mean that the electron trajectory must be carefully controlled to avoid beam collision with the waveguide walls. A wiggler system with half poles at entrance and exit is not an acceptable solution because of the offset is gives rise to the electron trajectory. Consequently, we have designed and constructed a wiggler magnet with exponential entrance and exit tapers for a minimal deflection and displacement of the electron beam. Simulations and experimental measurements showed that an on axis trajectory is easily obtainable.

  16. Dual-Phase Lock-In Amplifier Based on FPGA for Low-Frequencies Experiments.

    Science.gov (United States)

    Macias-Bobadilla, Gonzalo; Rodríguez-Reséndiz, Juvenal; Mota-Valtierra, Georgina; Soto-Zarazúa, Genaro; Méndez-Loyola, Maurino; Garduño-Aparicio, Mariano

    2016-03-16

    Photothermal techniques allow the detection of characteristics of material without invading it. Researchers have developed hardware for some specific Phase and Amplitude detection (Lock-In Function) applications, eliminating space and unnecessary electronic functions, among others. This work shows the development of a Digital Lock-In Amplifier based on a Field Programmable Gate Array (FPGA) for low-frequency applications. This system allows selecting and generating the appropriated frequency depending on the kind of experiment or material studied. The results show good frequency stability in the order of 1.0 × 10(-9) Hz, which is considered good linearity and repeatability response for the most common Laboratory Amplitude and Phase Shift detection devices, with a low error and standard deviation.

  17. Dual-Phase Lock-In Amplifier Based on FPGA for Low-Frequencies Experiments

    Directory of Open Access Journals (Sweden)

    Gonzalo Macias-Bobadilla

    2016-03-01

    Full Text Available Photothermal techniques allow the detection of characteristics of material without invading it. Researchers have developed hardware for some specific Phase and Amplitude detection (Lock-In Function applications, eliminating space and unnecessary electronic functions, among others. This work shows the development of a Digital Lock-In Amplifier based on a Field Programmable Gate Array (FPGA for low-frequency applications. This system allows selecting and generating the appropriated frequency depending on the kind of experiment or material studied. The results show good frequency stability in the order of 1.0 × 10−9 Hz, which is considered good linearity and repeatability response for the most common Laboratory Amplitude and Phase Shift detection devices, with a low error and standard deviation.

  18. Development of solenoid-induced helical wiggler with four poles per period

    CERN Document Server

    Ohigashi, N; Kiyochi, M; Nakao, N; Fujita, M; Imasaki, K; Nakai, S; Mima, K

    1999-01-01

    A new type of helical wiggler consisting of two staggered-iron arrays inserted into a solenoid field has been developed. The field measured by a test wiggler showed linear increment with the period. It was seen that 24% of the solenoid field contributed to the induced wiggler field when the gap length and the period of the wiggler were 16 and 24 mm, respectively. This wiggler would be useful for an FEL with a low-energy electron beam propagating in a strong axial guiding field.

  19. Development of solenoid-induced helical wiggler with four poles per period

    Science.gov (United States)

    Ohigashi, N.; Tsunawaki, Y.; Kiyochi, M.; Nakao, N.; Fujita, M.; Imasaki, K.; Nakai, S.; Mima, K.

    1999-06-01

    A new type of helical wiggler consisting of two staggered-iron arrays inserted into a solenoid field has been developed. The field measured by a test wiggler showed linear increment with the period. It was seen that 24% of the solenoid field contributed to the induced wiggler field when the gap length and the period of the wiggler were 16 and 24 mm, respectively. This wiggler would be useful for an FEL with a low-energy electron beam propagating in a strong axial guiding field.

  20. Extraction of accurate structure-factor amplitudes from Laue data: wavelength normalization with wiggler and undulator X-ray sources.

    Science.gov (United States)

    Srajer, V; Crosson, S; Schmidt, M; Key, J; Schotte, F; Anderson, S; Perman, B; Ren, Z; Teng, T Y; Bourgeois, D; Wulff, M; Moffat, K

    2000-07-01

    Wavelength normalization is an essential part of processing of Laue X-ray diffraction data and is critically important for deriving accurate structure-factor amplitudes. The results of wavelength normalization for Laue data obtained in nanosecond time-resolved experiments at the ID09 beamline at the European Synchrotron Radiation Facility, Grenoble, France, are presented. Several wiggler and undulator insertion devices with complex spectra were used. The results show that even in the most challenging cases, such as wiggler/undulator tandems or single-line undulators, accurate wavelength normalization does not require unusually redundant Laue data and can be accomplished using typical Laue data sets. Single-line undulator spectra derived from Laue data compare well with the measured incident X-ray spectra. Successful wavelength normalization of the undulator data was also confirmed by the observed signal in nanosecond time-resolved experiments. Single-line undulators, which are attractive for time-resolved experiments due to their high peak intensity and low polychromatic background, are compared with wigglers, based on data obtained on the same crystal.

  1. Pump-induced wavefront distortion in prototypical NIF/LMJ amplifiers-modeling and comparison with experiments

    Energy Technology Data Exchange (ETDEWEB)

    Erlandson, A; Jancaitis, K; LeTouze, G; Marshall, C; Rotter, M; Seznec, S; Zapata, L

    1998-09-01

    In large-aperture laser amplifiers such as those envisioned for the National Ignition Facility (NIF) and Laser Megajoules (LMJ) lasers, the geometry is such that the front and back faces of the laser slab are heated unevenly by the pump process. This uneven heating results in a mechanical deformation of the laser slab and consequent internal stresses. The deformation and stresses, along with a temperature-dependent refractive index variation, result in phase variations across the laser beam (so-called pump-induced wavefront distortions). These phase variations lead to beam steering which may affect frequency conversion as well as energy-on-target. We have developed a model which allows us to estimate the pump-induced wavefront distortion for a given amplifier configuration as well as the spatially-resolved depolarization. The model is compared with experiments taken in our amplifier development laboratory, AMPLAB

  2. Obtaining attosecond x-ray pulses using a self-amplified spontaneous emission free electron laser

    Directory of Open Access Journals (Sweden)

    A. A. Zholents

    2005-05-01

    Full Text Available We describe a technique for the generation of a solitary attosecond x-ray pulse in a free-electron laser (FEL, via a process of self-amplified spontaneous emission. In this method, electrons experience an energy modulation upon interacting with laser pulses having a duration of a few cycles within single-period wiggler magnets. Two consecutive modulation sections, followed by compression in a dispersive section, are used to obtain a single, subfemtosecond spike in the electron peak current. This region of the electron beam experiences an enhanced growth rate for FEL amplification. After propagation through a long undulator, this current spike emits a ∼250   attosecond x-ray pulse whose intensity dominates the x-ray emission from the rest of the electron bunch.

  3. Calculated and measured fields in superferric wiggler magnets

    Energy Technology Data Exchange (ETDEWEB)

    Blum, E.B.; Solomon, L. [Brookhaven National Lab., Upton, NY (United States)

    1995-02-01

    Although Klaus Halbach is widely known and appreciated as the originator of the computer program POISSON for electromagnetic field calculation, Klaus has always believed that analytical methods can give much more insight into the performance of a magnet than numerical simulation. Analytical approximations readily show how the different aspects of a magnet`s design such as pole dimensions, current, and coil configuration contribute to the performance. These methods yield accuracies of better than 10%. Analytical methods should therefore be used when conceptualizing a magnet design. Computer analysis can then be used for refinement. A simple model is presented for the peak on-axis field of an electro-magnetic wiggler with iron poles and superconducting coils. The model is applied to the radiator section of the superconducting wiggler for the BNL Harmonic Generation Free Electron Laser. The predictions of the model are compared to the measured field and the results from POISSON.

  4. Advanced optimization of permanent magnet wigglers using a genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Hajima, Ryoichi [Univ. of Tokyo (Japan)

    1995-12-31

    In permanent magnet wigglers, magnetic imperfection of each magnet piece causes field error. This field error can be reduced or compensated by sorting magnet pieces in proper order. We showed a genetic algorithm has good property for this sorting scheme. In this paper, this optimization scheme is applied to the case of permanent magnets which have errors in the direction of field. The result shows the genetic algorithm is superior to other algorithms.

  5. Electron trajectories in free electron laser with realizable helical wiggler and ion channel guiding

    Directory of Open Access Journals (Sweden)

    S. Ebrahimi

    2004-12-01

    Full Text Available   A detailed analysis of electron trajectories in a realizable helical wiggler free electron laser with ion channel guiding using electron (single particle dynamics is presented. Conditions for stability of electron orbit have been investigated, calculations are made to illustrate. Conclusion shows that there are differences stable (unstable condition(s electron trajectories between ideal helical wiggler(2D and realizable helical wiggler (3D.

  6. Superconducting wiggler magnets for beam-emittance damping rings

    CERN Document Server

    Schoerling, Daniel

    2012-01-01

    Ultra-low emittance beams with a high bunch charge are necessary for the luminosity performance of linear electron-positron colliders, such as the Compact Linear Collider (CLIC). An effective way to create ultra-low emittance beams with a high bunch charge is to use damping rings, or storage rings equipped with strong damping wiggler magnets. The remanent field of the permanent magnet materials and the ohmic losses in normal conductors limit the economically achievable pole field in accelerator magnets operated at around room temperature to below the magnetic saturation induction, which is 2.15 T for iron. In wiggler magnets, the pole field in the center of the gap is reduced further like the hyperbolic cosine of the ratio of the gap size and the period length multiplied by pi. Moreover, damping wiggler magnets require relatively large gaps because they have to accept the un-damped beam and to generate, at a small period length, a large magnetic flux density amplitude to effectively damp the beam emittance....

  7. Velocity drive for Mössbauer experiments using an amplifier with negative output impedance

    DEFF Research Database (Denmark)

    Løvborg, Leif

    1965-01-01

    A velocity drive of the constant acceleration type is described. Two mechanically coupled loudspeakers are used for the production of motion and the measurement of velocity respectively. In order to make the velocity response of the system independent of the mechanical parameters an amplifier hav...... having negative output impedance is used, which improves the stability of the system when overall negative feedback is introduced....

  8. Fiber Amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten

    2017-01-01

    The chapter provides a discussion of optical fiber amplifiers and through three sections provides a detailed treatment of three types of optical fiber amplifiers, erbium doped fiber amplifiers (EDFA), Raman amplifiers, and parametric amplifiers. Each section comprises the fundamentals including t...

  9. Three-dimensional simulation of long-wavelength free-electron lasers with helical wiggler and ion-channel guiding

    Institute of Scientific and Technical Information of China (English)

    F.Jafari Bahman; B.Maraghechi

    2013-01-01

    A three-dimensional simulation of a steady-state amplifier model of a long-wavelength free-electron laser (FEL) with realizable helical wiggler and ion-channel guiding is presented.The set of coupled nonlinear differential equations for electron orbits and fields of TE11 mode in a cylindrical waveguide are solved numerically by the Runge-Kutta algorithm with averages calculated by the Gaussian quadrature technique.Self-fields and space-charge effects are neglected,and the electron beam is assumed to be cold and slippage is ignored.The parameters correspond to the Compton regime.Evolution of the radiation power and growth rate along the wiggler is studied.Ion-channel density is chosen to obtain optimum efficiency.Simulations are preformed for the FEL operating in the neighborhood of 35 GHz and 16.5 GHz for the electron beam energies of 250 keV and 400 keV,respectively.The result of the saturated efficiency was found to be in good agreement with the simple estimation based on the phase-trapping model.

  10. Tunable microstrip SQUID amplifiers for the Gen 2 Axion Dark Matter eXperiment (ADMX)

    Science.gov (United States)

    O'Kelley, Sean; Hilton, Gene; Clarke, John; ADMX Collaboration

    2016-03-01

    We present a series of tunable microstrip SQUID (Superconducting Quantum Interference Device) amplifiers (MSAs) for installation in ADMX. The axion dark matter candidate is detected via Primakoff conversion to a microwave photon in a high-Q (~100,000) tunable microwave cavity cooled with a dilution refrigerator in a 7-tesla magnetic field. The microwave photon frequency ν is a function of the unknown axion mass, so both the cavity and amplifier must be scanned over a wide frequency range. An MSA is a linear, phase-preserving amplifier consisting of a square washer loop, fabricated from a thin Nb film, incorporating two Josephson tunnel junctions with resistive shunts to prevent hysteresis. The input is coupled via a microstrip made from a square Nb coil deposited over the washer with an intervening insulating layer. Tunability is achieved by terminating the microstrip with GaAs varactors that operate below 100 mK. By varying the varactor capacitance with a bias voltage, the resonant frequency is varied by up to a factor of 2. We demonstrate several devices operating below 100 mK, matched to the discrete operating bands of ADMX at frequencies ranging from 560 MHz to 1 GHz. The MSAs exhibit gains exceeding 20 dB and the associated noise temperatures, measured with a hot/cold load, approach the standard quantum limit (hν/kB) . Supported by DOE Grants DE - FG02 - 97ER41029, DE - FG02 - 96ER40956, DE - AC52 - 07NA27344, DE - AC03 - 76SF00098, and the Livermore LDRD program.

  11. Experimental observation of wiggler superradiance under group synchronism condition

    CERN Document Server

    Ginzburg, N S; Zotova, I V; Sergeev, A S; Phelps, A D R; Cross, A W; He, W; Ronald, K; Shpak, V G; Yalandin, M I; Shunailov, S A; Ulmaskulov, M R

    1999-01-01

    The first results of the observation of superradiance from a single, subnanosecond, high current, electron bunch passing through a wiggler immersed in a guide magnetic field are presented. The 300-500 ps microwave pulses were generated in the high gain regime for both the conventional and reverse directions of the guide magnetic field. The dependence of the radiation power on the interaction length as well as the absolute value of the power, 100-200 kW, were related with the development of self-bunching and consequently with coherent emission.

  12. Low-frequency quadrupole impedance of undulators and wigglers

    Science.gov (United States)

    Blednykh, A.; Bassi, G.; Hidaka, Y.; Smaluk, V.; Stupakov, G.

    2016-10-01

    An analytical expression of the low-frequency quadrupole impedance for undulators and wigglers is derived and benchmarked against beam-based impedance measurements done at the 3 GeV NSLS-II storage ring. The adopted theoretical model, valid for an arbitrary number of electromagnetic layers with parallel geometry, allows to calculate the quadrupole impedance for arbitrary values of the magnetic permeability μr . In the comparison of the analytical results with the measurements for variable magnet gaps, two limit cases of the permeability have been studied: the case of perfect magnets (μr→∞ ), and the case in which the magnets are fully saturated (μr=1 ).

  13. Experimental results of a sheet-beam, high power, FEL amplifier with application to magnetic fusion research

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, S.; Destler, W.W.; Granatstein, V.L. [Univ. of Maryland, College Park, MD (United States)] [and others

    1995-12-31

    The experimental study of sheet-beam FELs as candidate millimeter-wave sources for heating magnetic fusion plasmas has achieved a major milestone. In a proof-of-principle, pulsed experiment, saturated FEL amplifier operation was achieved with 250 kW of output power at 86 GHz. Input microwave power was 1 kW, beam voltage was 450 kV and beam current was 17 A. The planar wiggler had a peak value of 3.8 kG, a period of 0.96 cm and was 71 cm long. The linear gain of 30 dB, saturated gain of 24 dB and saturated efficiency of 3% all are in good agreement with theoretical prediction. Follow-on work would include development of a thermionic sheet-beam electron-gun compatible with CW FEL operation, adding a section of tapered wiggler to increase the output power to levels in excess of 1 megawatt, and increasing the FEL frequency.

  14. Prospects for searching axion-like particle dark matter with dipole, toroidal and wiggler magnets

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Oliver K. [Yale Univ., New Haven, CT (United States). Dept. of Physics; Betz, Michael; Caspers, Fritz [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Jaeckel, Joerg [Institute for Particle Physics Phenomenology, Durham (United Kingdom); Lindner, Axel; Ringwald, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Semertzidis, Yannis [Brookhaven National Lab., Upton, NY (United States); Sikivie, Pierre [Florida Univ., Gainesville, FL (United States). Dept. of Physics; Zioutas, Konstantin [Patras Univ. (Greece)

    2011-10-15

    In this work we consider searches for dark matter made of axions or axion-like particles (ALPs) using resonant radio frequency cavities inserted into dipole magnets from particle accelerators, wiggler magnets developed for accelerator based advanced light sources, and toroidal magnets similar to those used in particle physics detectors. We investigate the expected sensitivity of such ALP dark matter detectors and discuss the engineering aspects of building and tuning them. Brief mention is also made of even stronger field magnets that are becoming available due to improvements in magnetic technology. It is concluded that new experiments utilizing already existing magnets could greatly enlarge the mass region in searches for axion-like dark matter particles. (orig.)

  15. Information overload or search-amplified risk? Set size and order effects on decisions from experience.

    Science.gov (United States)

    Hills, Thomas T; Noguchi, Takao; Gibbert, Michael

    2013-10-01

    How do changes in choice-set size influence information search and subsequent decisions? Moreover, does information overload influence information processing with larger choice sets? We investigated these questions by letting people freely explore sets of gambles before choosing one of them, with the choice sets either increasing or decreasing in number for each participant (from two to 32 gambles). Set size influenced information search, with participants taking more samples overall, but sampling a smaller proportion of gambles and taking fewer samples per gamble, when set sizes were larger. The order of choice sets also influenced search, with participants sampling from more gambles and taking more samples overall if they started with smaller as opposed to larger choice sets. Inconsistent with information overload, information processing appeared consistent across set sizes and choice order conditions, reliably favoring gambles with higher sample means. Despite the lack of evidence for information overload, changes in information search did lead to systematic changes in choice: People who started with smaller choice sets were more likely to choose gambles with the highest expected values, but only for small set sizes. For large set sizes, the increase in total samples increased the likelihood of encountering rare events at the same time that the reduction in samples per gamble amplified the effect of these rare events when they occurred-what we call search-amplified risk. This led to riskier choices for individuals whose choices most closely followed the sample mean.

  16. Planar electron beams in a wiggler magnet array

    Indian Academy of Sciences (India)

    Arti Hadap; K C Mittal

    2013-02-01

    Transport of high current (∼kA range with particle energy ∼ 1 MeV) planar electron beams is a topic of increasing interest for applications in high-power (1–10 GW) and high-frequency (10–20 GHz) microwave devices such as backward wave oscillator (BWO), klystrons, gyro-BWOs, etc. In this paper, we give a simulated result for transport of electron beams with velocity $V_{b} = 5.23 × 10^{8}$ cm s-1 , relativistic factor = 1.16, and beam voltage = ∼80 kV in notched wiggler magnet array. The calculation includes self-consistent effects of beam-generated fields. Our results show that the notched wiggler configuration with ∼6.97 kG magnetic field strength can provide vertical and horizontal confinements for a sheet electron beam with 0.3 cm thickness and 2 cm width. The feasibility calculation addresses to a system expected to drive for 13–20 GHz BWO with rippled waveguide parameters as width = 3.0 cm, thickness = 1.0 cm, corrugation depth ℎ = 0.225 cm, and spatial periodicity = 1.67 cm.

  17. Wireless Josephson amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Narla, A.; Sliwa, K. M.; Hatridge, M.; Shankar, S.; Frunzio, L.; Schoelkopf, R. J.; Devoret, M. H. [Department of Applied Physics, Yale University, New Haven, Connecticut 06511 (United States)

    2014-06-09

    Josephson junction parametric amplifiers are playing a crucial role in the readout chain in superconducting quantum information experiments. However, their integration with current 3D cavity implementations poses the problem of transitioning between waveguide, coax cables, and planar circuits. Moreover, Josephson amplifiers require auxiliary microwave components, like directional couplers and/or hybrids, that are sources of spurious losses and impedance mismatches that limit measurement efficiency and amplifier tunability. We have developed a wireless architecture for these parametric amplifiers that eliminates superfluous microwave components and interconnects. This greatly simplifies their assembly and integration into experiments. We present an experimental realization of such a device operating in the 9–11 GHz band with about 100 MHz of amplitude gain-bandwidth product, on par with devices mounted in conventional sample holders. The simpler impedance environment presented to the amplifier also results in increased amplifier tunability.

  18. Ultrahigh-vacuum facility for high-resolution grazing-angle X-ray diffraction at a vertical wiggler source of synchrotron radiation.

    Science.gov (United States)

    Sakata, O; Tanaka, Y; Nikolaenko, A M; Hashizume, H

    1998-07-01

    A versatile ultrahigh-vacuum chamber has been designed for grazing-angle X-ray standing-wave and diffraction experiments at the vertical wiggler source of the Photon Factory. Unlike at other sources, the vertically polarized X-rays from the wiggler favour the use of a horizontal scattering geometry. The X-ray chamber is equipped with a hemispherical beryllium window, which allows any scattering angle to be attained and secondary emissions to be measured. The chamber is of a compact design, sitting on a precision rotary table which is rotated for scans. Samples are introduced from a portable vessel. The whole procedure can be performed in a vacuum better than 10(-7) Pa. The system has successfully been applied to a grazing-angle X-ray standing-wave experiment, which determined the dimer bond length and the domain structure of Si(001) surfaces deposited with monolayer arsenic.

  19. Electron-beam confinement by rotational stabilization in a linear wiggler free electron laser

    Energy Technology Data Exchange (ETDEWEB)

    Friedland, L.; Shefer, R.E. (Science Research Laboratory, Inc., Somerville, MA (USA))

    1990-11-15

    Finite radius electron-beam transport in a linear wiggler free-electron laser with a guide magnetic field is investigated. The addition of a guide magnetic field improves the beam confinement, but also leads to a detrimental drift in the direction transverse to the wiggler magnetic field. The introduction of a rotational transformation of the wiggler magnetic field is proposed to further improve the beam confinement. It is shown that the transformation results in a stable, uniform, solid body rotation of the beam provided (a) the guide field is larger than the amplitude of the wiggler field, (b) the electron drift velocity is much smaller than the rotation speed of the wiggler field as seen by the beam, and (c) the wiggler field rotates in the direction opposite to the direction of the electron gyromotion in the guide field. Theoretical predictions of the improvement of the radial beam transport with the introduction of the rotation of the wiggler field are confirmed in numerical simulations.

  20. Low-frequency quadrupole impedance of undulators and wigglers

    Directory of Open Access Journals (Sweden)

    A. Blednykh

    2016-10-01

    Full Text Available An analytical expression of the low-frequency quadrupole impedance for undulators and wigglers is derived and benchmarked against beam-based impedance measurements done at the 3 GeV NSLS-II storage ring. The adopted theoretical model, valid for an arbitrary number of electromagnetic layers with parallel geometry, allows to calculate the quadrupole impedance for arbitrary values of the magnetic permeability μ_{r}. In the comparison of the analytical results with the measurements for variable magnet gaps, two limit cases of the permeability have been studied: the case of perfect magnets (μ_{r}→∞, and the case in which the magnets are fully saturated (μ_{r}=1.

  1. CSEM-Steel hybrid wiggler/undulator magnetic field studies

    Energy Technology Data Exchange (ETDEWEB)

    Halbach, K.; Hoyer, E.; Marks, S.; Plate, D.; Shuman, D.

    1985-06-01

    Current design of permanent magnet wiggler/undulators use either pure charge sheet equivalent material (CSEM) or the CSEM-Steel hybrid configuration. Hybrid configurations offer higher field strength at small gaps, field distributions dominated by the pole surfaces and pole tuning. Nominal performance of the hybrid is generally predicted using a 2-D magnetic design code neglecting transverse geometry. Magnetic measurements are presented showing transverse configuration influence on performance, from a combination of models using CSEMs, REC (H/sub c/ = 9.2 KOe) and NdFe (H/sub c/ = 10.7 kOe), different pole widths and end configurations. Results show peak field improvement using NdFe in place of REC in identical models, gap peak field decrease with pole width decrease (all results less than computed 2-D fields), transverse gap field distributions, and importance of CSEM material overhanging the poles in the transverse direction for highest gap fields. 3 refs., 6 figs.

  2. Absorber for wakefield interference management at the entrance of the wiggler of a free electron laser

    Science.gov (United States)

    Marchlik, Matthew; Biallas, George Herman

    2017-03-07

    A method for managing the broad band microwave and TeraHertz (THz) radiation in a free electron laser (FEL) having a wiggler producing power in the electromagnetic spectrum. The method includes placement of broadband microwave and TeraHertz (THz) radiation absorbers on the upstream end of the wiggler. The absorbers dampen the bounced back, broad band microwave and THz radiation returning from the surfaces outside the nose of the cookie-cutter and thus preventing broadening of the electron beam pulse's narrow longitudinal energy distribution. Broadening diminishes the ultimate laser power from the wiggler. The broadband microwave and THz radiation absorbers are placed on either side of the slot in the cookie-cutter that shapes the wake field wave of the electron pulse to the slot shape of the wiggler chamber aperture. The broad band microwave and THz radiation absorber is preferably a non-porous pyrolytic grade of graphite with small grain size.

  3. An ultimate storage ring lattice with vertical emittance generated by damping wigglers

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xiaobiao [SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)

    2015-01-06

    We discuss the approach of generating round beams for ultimate storage rings using vertical damping wigglers (with horizontal magnetic field). The vertical damping wigglers provide damping and excite vertical emittance. This eliminates the need to generate large linear coupling that is impractical with traditional off-axis injection. We use a PEP-X compatible lattice to demonstrate the approach. This lattice uses separate quadrupole and sextupole magnets with realistic gradient strengths. Intrabeam scattering effects are calculated. As a result, the horizontal and vertical emittances are 22.3 pm and 10.3 pm, respectively, for a 200 mA, 4.5 GeV beam, with a vertical damping wiggler of a total length of 90 m, a peak field of 1.5 T and a wiggler period of 100 mm.

  4. Absorber for wakefield interference management at the entrance of the wiggler of a free electron laser

    Energy Technology Data Exchange (ETDEWEB)

    Marchlik, Matthew; Biallas, George Herman

    2017-03-07

    A method for managing the broad band microwave and TeraHertz (THz) radiation in a free electron laser (FEL) having a wiggler producing power in the electromagnetic spectrum. The method includes placement of broadband microwave and TeraHertz (THz) radiation absorbers on the upstream end of the wiggler. The absorbers dampen the bounced back, broad band microwave and THz radiation returning from the surfaces outside the nose of the cookie-cutter and thus preventing broadening of the electron beam pulse's narrow longitudinal energy distribution. Broadening diminishes the ultimate laser power from the wiggler. The broadband microwave and THz radiation absorbers are placed on either side of the slot in the cookie-cutter that shapes the wake field wave of the electron pulse to the slot shape of the wiggler chamber aperture. The broad band microwave and THz radiation absorber is preferably a non-porous pyrolytic grade of graphite with small grain size.

  5. Vacuum chamber with distributed titanium sublimation pumping for the G-line wiggler at Cornell High Energy Synchrotron Source

    Science.gov (United States)

    Li, Y.; He, Y.; Mistry, N. B.

    2003-07-01

    This article describes a 3-m-long vacuum chamber for the new wiggler magnet at the Cornell Electron Storage Ring (CESR) for the synchrotron light beam line of the Cornell High Energy Synchrotron Source (CHESS). Copper was chosen as the main chamber material for its good electric and thermal conductivities. Proper mechanical design and welding procedure were implemented to meet very tight tolerances to ensure adequate vertical aperture for the stored beams in CESR while allowing the required small wiggler gap. Distributed titanium sublimation pumping is incorporated along the 3 m length of the chamber to provide sufficient pumping speed and capacity for CESR and CHESS operations. The chamber pumping performance was evaluated prior to installation. Linear distributed pumping speeds at the beam line of ~720 l/s/m for N2 and CO and ~4000 l/s/m for H2 were measured. The measured pumping capacities for N2, CO and H2 are ~1.0, ~2.0 and ~77 Torr l, respectively, for each titanium sublimation cycle. Measurements also showed that CO molecules adsorb on the N2 and H2 saturated titanium films with virtually the same initial sticking coefficient as on a fresh titanium film. Analyses indicated very different CO adsorption mechanisms between the N2 and H2 saturated titanium films. While the replacement of surface H2 by CO was observed, little desorption of nitrogen was measured. Operational experience showed excellent vacuum pumping performance over two years after the chamber installation.

  6. Amplified transduction of Planck-scale effects for quantum optical experiments

    CERN Document Server

    Bosso, Pasquale; Pikovski, Igor; Vanner, Michael R

    2016-01-01

    The unification of quantum mechanics and gravity remains one of the main challenges in modern physics. Quantum-gravity-inspired phenomenological models offer a window to explore potential aspects of such a theory including observable consequences. One such phenomenological model is the Generalized Uncertainty Principle (GUP), which predicts a modified Heisenberg uncertainty relation and a deformed canonical commutator. It was recently shown that under some assumptions, opto-mechanical systems can put stringent experimental bounds on such models. In this paper, we introduce a scheme to increase the sensitivity of these experiments with an extended sequence of optomechanical interactions. We also analyze the effects of optical phase noise and optical loss and present a strategy to mitigate such deleterious effects.

  7. Operational amplifiers

    CERN Document Server

    Dostal, Jiri

    1993-01-01

    This book provides the reader with the practical knowledge necessary to select and use operational amplifier devices. It presents an extensive treatment of applications and a practically oriented, unified theory of operational circuits.Provides the reader with practical knowledge necessary to select and use operational amplifier devices. Presents an extensive treatment of applications and a practically oriented, unified theory of operational circuits

  8. Operational Amplifiers.

    Science.gov (United States)

    Foxcroft, G. E.

    1986-01-01

    Addresses the introduction of low cost equipment into high school and college physical science classes. Examines the properties of an "ideal" operational amplifier and discusses how it might be used under saturated and non-saturated conditions. Notes the action of a "real" operational amplifier. (TW)

  9. Development of a Single-Pass Amplifier for an Optical Stochastic Cooling Proof-of-Principle Experiment at Fermilab's IOTA Facility

    Energy Technology Data Exchange (ETDEWEB)

    Andorf, M. B. [NICADD, DeKalb; Lebedev, V. A. [Fermilab; Piot, P. [NIU, DeKalb

    2015-06-01

    Optical stochastic cooling (OSC) is a method of beam cooling which is expected to provide cooling rates orders of magnitude larger than ordinary stochastic cooling. Light from an undulator (the pickup) is amplified and fed back onto the particle beam via another undulator (the kicker). Fermilab is currently exploring a possible proof-of-principle experiment of the OSC at the integrable-optics test accelerator (IOTA) ring. To implement effective OSC a good correction of phase distortions in the entire band of the optical amplifier is required. In this contribution we present progress in experimental characterization of phase distortions associated to a Titanium Sapphire crystal laser-gain medium (a possible candidate gain medium for the OSC experiment to be performed at IOTA). We also discuss a possible option for a mid-IR amplifier

  10. Design study of a G-band FEL amplifier for application to cyclotron resonant heating in magnetic fusion reactors

    Science.gov (United States)

    Freund, H. P.; Read, M. E.; Jackson, R. H.; Pershing, D. E.; Taccetti, J. M.

    1995-04-01

    A G-band (140-150 GHz) free-electron laser is described using a coaxial hybrid iron (CHI) wiggler. The CHI wiggler is produced by insertion into a solenoid of a central rod and an outer ring composed of alternating ferrite and nonferrite spacers. The position of the spacers is such that the ferrite (nonferrite) spacers on the central rod are opposite the nonferrite (ferrite) spacers on the outer ring. The field is cylindrically symmetric and exhibits minima in the center of the gap providing for enhanced beam focusing. We describe a tapered wiggler amplifier for plasma heating applications. Preliminary design studies using a nonlinear simulation indicates that output powers of 3.5 MW are possible using a 690 kV/40 A electron beam for a total efficiency of 13%. It is important to note that no beam loss was observed even for realistic values of beam energy spread.

  11. 740 Gbit/s (37 x 20 Gbit/s) DWDM Transmission Experiment Using Er~(3+)-Doped Tellurite Fiber Amplifiers and Distributed Raman Amplification

    Institute of Scientific and Technical Information of China (English)

    Hiroyuki; Toda; Maoki; Suzuki; Ryo; Takami; Tetsuya; Miyazaki; Takeshi; Makino; Fumito; Kubota

    2003-01-01

    We demonstrate 740 Gbit/s (37 x 20 Gbit/s) DWDM recirculating transmission experiment with 59 nm continuous bandwidth over 300 km by employing Er3+-doped tellurite fiber amplifiers. The use of Raman amplification is effective to increase the transmission bandwidth.

  12. The 8 cm Period Electromagnetic Wiggler Magnet with Coils Made from Sheet Copper

    CERN Document Server

    Biallas, George H; Hiatt, Tommy; Neil, George R; Snyder, Michael D

    2005-01-01

    An electromagnetic wiggler, now lasing at the Jefferson Lab FEL, has 29 eight cm periods with K variable from 0.6 to1.1 and gap of 2.6 cm. The wiggler was made inexpensively in 11 weeks by an industrial machine shop. The conduction cooled coil design uses copper sheet material cut to forms using water jet cutting. The conductor is cut to serpentine shapes and the cooling plates are cut to ladder shape. The sheets are assembled in stacks insulated with polymer film, also cut with water jet. The coil design extends the serpentine conductor design of the Duke OK4 to more and smaller conductors. The wiggler features graded fields in the two poles at each end and trim coils on these poles to eliminate field errors caused by saturation. An added critical feature is mirror plates at the ends with integral trim coils to eliminate three dimensional end field effects and align the entrance and exit orbit with the axis of the wiggler. Details of construction, measurement methods and excellent wiggler performance are pre...

  13. Feasibility Study on Introducing a Superconducting Wiggler to Saga Light Source

    CERN Document Server

    Koda, Shigeru; Ohgaki, Hideaki; Okajima, Toshihiro; Setoyama, Hiroyuki; Takabayashi, Yuichi; Tomimasu, Takio; Torikoshi, Masami; Yoshida, Katuhide

    2005-01-01

    Saga light source (SAGA-LS) is the synchrotron radiation facility, which consists of 250 MeV electron linac and 1.4 GeV storage ring. We have a plan to introduce an existing superconducting wiggler, which has been developed for other project by National Institute of Radiological Sciences. The superconducting wiggler consists of a main pole of 7T and two side poles of 4T. Each pole is composed of a racetrack-shaped coil and an iron core. We have examined the effects of the wiggler on the beam optics when it is introduced into SAGA-LS. The distribution of multipole components in the planes perpendicular to the electron orbit, which is deformed by the wiggler fields, have been calculated using magnetic field calculation code RADIA. Then the lattice function and the dynamic aperture of the ring have been calculated by the lattice calculation code SAD. The results show that the tune shift due to the quadrupole component of the wiggler field is as large as to make horizontal beam orbit unstable. The dynamic apertur...

  14. Superconducting wiggler with semi-cold beam duct at Taiwan light source

    Science.gov (United States)

    Hwang, C.-S.; Chang, C.-H.; Chen, H.-H.; Lin, F.-Y.; Fan, T.-C.; Huang, M.-H.; Jan, J.-C.; Hsu, K.-T.; Chen, J.; Hsu, S.-N.; Hsiung, G.-Y.; Chang, H.-P.; Kuo, C.-C.; Chien, Y.-C.; Hsiao, F.-Z.; Chen, J.-R.; Chen, C.-T.

    2006-01-01

    A 3.2 T superconducting wiggler with a periodic length of 6 cm and 32 poles was designed and fabricated as an X-ray source. The beam duct of this magnet is a semi-cold, ultra-high vacuum chamber that consists of an aluminum and stainless steel taper. The number of poles in this magnet design is even, to minimize the integral strengths of the multipole components. Two measurement systems—involving room-temperature and cryogenic Hall probes—were set up to measure the field of the superconducting wiggler. A cryogenic plant that supplied liquid helium and nitrogen to the superconducting wiggler has already been established. The performance of magnet construction is good and the commissioning of the superconducting wiggler in the storage ring has been successful. No trim coil compensation on the magnet is required to adjust the electron beam orbit. Furthermore, the electron beams exhibit no loss and remain highly stable after the superconducting wiggler has been quenched.

  15. Simplified design of IC amplifiers

    CERN Document Server

    Lenk, John

    1996-01-01

    Simplified Design of IC Amplifiers has something for everyone involved in electronics. No matter what skill level, this book shows how to design and experiment with IC amplifiers. For experimenters, students, and serious hobbyists, this book provides sufficient information to design and build IC amplifier circuits from 'scratch'. For working engineers who design amplifier circuits or select IC amplifiers, the book provides a variety of circuit configurations to make designing easier.Provides basics for all phases of practical design.Covers the most popular forms for amplif

  16. Near-ideal lasing with a uniform wiggler

    Energy Technology Data Exchange (ETDEWEB)

    Warren, R.W.; Sollid, J.E.; Feldman, D.W.; Stein, W.E.; Johnson, W.J.; Lumpkin, A.H.; Goldstein, J.C.

    1988-01-01

    Over the years the Los Alamos FEL team has reduced or eliminated many of the experimental problems that resulted in non-ideal lasing. The major problems were accelerator instabilities that cause noise and fluctuations in current, energy, and timing; wakefield effects in the wiggler and beamline that introduce fluctuations in the beam's energy; and mirror nonlinearities caused by free carriers produced in the mirror by the high light levels, which caused extra light losses and interfered with the diagnostics. Lasing is not thought to be ideal in that it lacks major disturbing effects and is limited only by emittance, energy spread, and peak current. In this paper we describe the features of lasing that we have observed over a range of optical power of 1000, from the onset of lasing, to the threshold of the sideband instability, to the organization of regular optical spikes, to the region of chaotic spikes. Cavity-length detuning is presented as an ideal technique, in most circumstances, to completely suppress sidebands. With detuning one can easily switch operating modes from that giving the highest efficiency (chaotic spiking) to that giving the narrowest spectral line (no sidebands). Alternative techniques for sideband suppression normally use some kind of wavelength selective device (e.g., a grating) inserted in the cavity. With detuning, there is no need for such a device, and, therefore, no conflict between the wavelength control exerted by this extra optical component and that exerted by the energy of the electron beam. Lasing, therefore, starts easily, a shift in wavelength, i.e., chirp, is easily accomplished, and the consequences of inadequate control of the electron beam energy are not severe. 35 refs., 16 figs.

  17. Making an Inexpensive Electromagnetic Wiggler Using Sheet Materials for the Coils

    CERN Document Server

    Herman-Biallas, George; Hiatt, Thomas; Neil, George; Snyder, Michael

    2004-01-01

    An inexpensive electromagnetic wiggler, made with twenty-eight, 4 cm periods with a K of 1 and gap of 2.6 cm was made within 10 weeks after receipt of order by an industrial machine shop. The coil design used sheet and plate materials cut to shapes using water jet cutting and was assembled in a simple stack design. The coil design extends the serpentine conductor design of the Duke OK4 to more and smaller conductors. The coils are conduction cooled to imbedded cooling plates. The wiggler features graded end pole fields, trim coil compensation for end field errors and mirror plates on the ends to avoid three dimensional end field effects. Details of the methods used in construction and the wiggler performance are presented.

  18. Global Beta-beating Compensation of the ALS W16 Wiggler.

    Science.gov (United States)

    Robin, David; Nishimura, Hiroshi; Safranek, James

    1997-05-01

    The W16 wiggler is the first wiggler and highest field insertion device to be installed in the ALS storage ring. When the gaps of the W16 wiggler are closed, the vertical tune increases by 0.07 and the vertical beta function is distorted by 35 %. There are 48 quadrupoles in the ring whose fields can be adjusted individually to restore the tunes and partially compensate the beta beating. In order to adjust the quadrupole field strengths to accurately compensate the focussing, it is necessary to have a method to precisely determine the beta-beating. In this paper we compare measurements of the induced beta-beating using two methods: measuring the tune dependence on quadrupole field strength and fitting a lattice model with measured response matricies. The fitted model also allows us to predict quadrupole field strengths that will best compensate the beta beating. These quadrupole field strengths are then applied and the resultant beta-beating is measured.

  19. Higher harmonic emission by a relativistic electron beam in a longitudinal magnetic wiggler

    Science.gov (United States)

    Davidson, Ronald C.; McMullin, Wayne A.

    1982-10-01

    The classical limit of the Einstein-coefficient method is used in the low-gain regime to calculate the stimulated emission from a tenuous relativistic electron beam propagating in the combined solenoidal and longitudinal wiggler fields (B0+δB k0z)e^z produced near the axis of a multiple-mirror (undulator) field configuration. Emission is found to occur at all harmonics of the wiggler wave number k0 with Doppler upshifted output frequency given by ω=(lk0Vb+ωcb)(1+Vbc)γ2b(1+γ2bV2⊥c2), where l>=1. The emission is compared to the low-gain cyclotron maser with δB=0 and to the low-gain free-electron laser (operating at higher harmonics) utilizing a transverse linearly polarized wiggler field.

  20. Design and System Integration of the Superconducting Wiggler Magnets for the Compact Linear Collider Damping Rings

    CERN Document Server

    Schoerling, D; Bernhard, A; Bragin, A; Karppinen, M; Maccaferri, R; Mezentsev, N; Papaphilippou, Y; Peiffer, P; Rossmanith, R; Rumolo, G; Russenschuck, S; Vobly, P; Zolotarev, K

    2012-01-01

    To achieve high luminosity at the collision point of the Compact Linear Collider (CLIC) the normalized horizontal and vertical emittances of the electron and positron beams must be reduced to 500 nm and 4 nm before the beams enter the 1.5TeV linear accelerators. An effective way to accomplish ultra-low emittances with only small effects on the electron polarization is using damping rings operating at 2.86 GeV equipped with superconducting wiggler magnets. This paper describes a technical design concept for the CLIC damping wigglers.

  1. Bi-directional four wave mixing in semiconductor amplifiers for mid-span spectral inversion: theory and experiment

    DEFF Research Database (Denmark)

    Bischoff, Svend; Buxens, Alvaro A.; Poulsen, Henrik Nørskov

    1999-01-01

    Summary form only given. We have developed a large signal model to theoretically assess the performance of a mid span spectral inversion (MSSI) transmission system. The large signal model has previously been used to successfully model the fast gain dynamics of semiconductor optical amplifiers....

  2. Low-frequency wiggler modes in the free-electron laser with a dusty magnetoplasma medium

    Science.gov (United States)

    Jafari, S.

    2015-07-01

    An advanced incremental scheme for generating tunable coherent radiation in a free-electron laser has been presented: the basic concept is the use of a relativistic electron beam propagating through a magnetized dusty plasma channel where dust helicon, dust Alfven and coupled dust cyclotron-Alfven waves can play a role as a low-frequency wiggler, triggering coherent emissions. The wiggler wavelength at the sub-mm level allows one to reach the wavelength range from a few nm down to a few Å with moderately relativistic electrons of kinetic energies of a few tens/hundreds of MeV. The laser gain and the effects of beam self-electric and self-magnetic fields on the gain have been estimated and compared with findings of the helical magnetic and electromagnetic wigglers in vacuum. To study the chaotic regions of the electron motion in the dusty plasma wave wiggler, a time independent Hamiltonian has been obtained. The Poincare surface of a section map has been used numerically to analyze the nonintegrable system where chaotic regions in phase-space emerge. This concept opens a path toward a new generation of synchrotron sources based on compact plasma structures.

  3. JLAMP: AN AMPLIFIER-BASED FEL IN THE JLAB SRF ERL DRIVER

    Energy Technology Data Exchange (ETDEWEB)

    Kevin Jordan; Stephen V. Benson; David Douglas; Pavel Evtushenko; Carlos Hernandez-Garcia; George R. Neil

    2007-06-13

    Notional designs for energy-recovering linac (“ERL”) -driven high average power free electron lasers (“FEL”s) often invoke amplifier-based architectures. To date, however, amplifier FELs have been limited in average power output to values several orders of magnitude lower than those demonstrated in optical-resonator based systems; this is due at least in part to the limited electron beam powers available from their driver accelerators. In order to directly contrast the performance available from amplifiers to that provided by high-power cavity-based resonators, we have developed a scheme to test an amplifier FEL in the JLab SRF ERL driver. We describe an accelerator system design that can seamlessly and non-invasively integrate a 10 m wiggler into the existing system and which provides, at least in principle, performance that would support high-efficiency lasing in an amplifier configuration. Details of the design and an accelerator performance analysis will be presented

  4. Anomalously Strong Scattering of Spontaneously Produced Laser Radiation in the First Free-Electron Laser and Study of Free-Electron Two-Quantum Stark Lasing in an Electric Wiggler with Quantum-Wiggler Electrodynamics

    Institute of Scientific and Technical Information of China (English)

    S. H. Kim

    2006-01-01

    We calculate the scattering cross section of an electron with respect to the spontaneously produced laser radiation in the first free-electron laser (FEL) with quantum-wiggler electrodynamics (QWD). The cross section is 1016 times the Thomson cross section, confirming the result obtained by a previous analysis of the experimental data. A QWD calculation show that spontaneous emission in an FEL using only an electric wiggler can be very strong while amplification through net stimulated emission is practically negligible.

  5. TARC: Carlo Rubbia's Energy Amplifier

    CERN Multimedia

    Laurent Guiraud

    1997-01-01

    Transmutation by Adiabatic Resonance Crossing (TARC) is Carlo Rubbia's energy amplifier. This CERN experiment demonstrated that long-lived fission fragments, such as 99-TC, can be efficiently destroyed.

  6. The Beam Line X NdFe-steel hybrid wiggler for SSRL

    Energy Technology Data Exchange (ETDEWEB)

    Hoyer, E.; Halbach, K.; Humphries, D.; Marks, S.; Plate, D.; Shuman, D.; Karpenko, V.P.; Kulkarni, S.; Tirsell, K.G.

    1987-03-10

    A wiggler magnet with 15 periods, each 12.85 cm long, which achieves 1.40 T at a 2.1 cm gap (2.26T at 0.8 cm) has been designed and is now in fabrication at LBL. This wiggler will be the radiation source of the high intensity synchrotron radiation beam line for the Beam Line X PRT facility at SSRL. The magnet utilizes Neodymium-Iron (NdFe) material and Vanadium Permendur (steel) in the hybrid configuration to achieve simultaneously a high magnetic field and short period. Magnetic field adjustment is with a driven chain and ball screw drive system. The magnetic structure is external to an s.s. vacuum chamber which has thin walls, 0.76 mm thickness, at each pole tip for higher field operation. Magnetic design, construction details and magnetic measurements are presented.

  7. Adaptive silicon monochromators for high-power wigglers; design, finite-element analysis and laboratory tests.

    Science.gov (United States)

    Quintana, J P; Hart, M

    1995-05-01

    Multipole wigglers in storage rings already produce X-ray power in the range up to a few kilowatts and planned devices at third-generation facilities promise up to 30 kW. Although the power density at the monochromator position is an order of magnitude lower than that from undulators, the thermal strain field in the beam footprint can still cause severe loss of performance in X-ray optical systems. For an optimized adaptive design, the results of finite-element analysis are compared with double-crystal rocking curves obtained with a laboratory X-ray source and, in a second paper [Quintana, Hart, Bilderback, Henderson, Richter, Setterson, White, Hausermann, Krumrey & Schulte-Schrepping (1995). J. Synchotron Rad. 2, 1-5], successful tests at wiggler sources at CHESS and ESRF and in an undulator source at HASYLAB are reported.

  8. High-Q Contacted Ring Microcavities with Scatterer-Avoiding "Wiggler" Bloch Wave Supermode Fields

    CERN Document Server

    Liu, Yangyang

    2014-01-01

    High-Q ring resonators with contacts to the waveguide core provide a versatile platform for various applications in chip-scale optomechanics, thermo- and electro-optics. We propose and demonstrate a novel approach to implement azimuthally periodic contacted ring resonators based on multi-mode Bloch matching that support contacts on both the inner and outer radius edges with small degradation to the optical Q. Radiative coupling between degenerate modes of adjacent transverse spatial order leads to imaginary frequency (Q) splitting and a scatterer avoiding high-Q "wiggler" supermode field. We experimentally measure Q's up to 258,000 in devices fabricated in a silicon device layer on buried oxide undercladding, and up to 139,000 in devices fully suspended in air using an undercut step. Wiggler supermodes are true modes of the microphotonic system that offer new degrees of freedom in electrical, thermal and mechanical design.

  9. Nonlinear Optimization of CLIC DRS New Design with Variable Bends and High Field Wigglers

    CERN Document Server

    Ghasem, H.; Alabau-Gonzalvo, J.; Papadopoulou, S.; Papaphilippou, Y.

    2016-01-01

    The new design of CLIC damping rings is based on longitudinal variable bends and high field superconducting wiggler magnets. It provides an ultra-low horizontal normalised emittance of 412 nm-rad at 2.86 GeV. In this paper, nonlinear beam dynamics of the new design of the damping ring (DR) with trapezium field profile bending magnets have been investigated in detail. Effects of the misalignment errors have been studied in the closed orbit and dynamic aperture.

  10. The Spontaneous Radiation of Electrons in a Plane Wiggler with Inhomogeneous Magnetic Field

    CERN Document Server

    Ayryan, E A; Izmailian, N Sh; Oganesyan, K B

    2016-01-01

    The spectral distribution of spontaneous emission of electrons moving in a plane wiggler with inhomogeneous magnetic field is calculated. We show that electrons do complicated motion consisting of slow(strophotron) and fast(undulator) parts. The equations of motion are averaged over fast undulator part and we obtain equations for connected motion. It is shown, that the account of inhomogenity of the magnetic field leads to appearance of additional peaks in the spectral distribution of spontaneous radiation.

  11. Conceptual Design of a Three-Pole Wiggler for the APS Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Abliz, M. [Argonne National Lab. (ANL), Argonne, IL (United States); Grimmer, J. [Argonne National Lab. (ANL), Argonne, IL (United States); Dejus, R. [Argonne National Lab. (ANL), Argonne, IL (United States); Ramanathan, M. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-07-01

    The current design of the Advanced Photon Source Upgrade (APS-U) project is a multi-bend achromat (MBA) lattice, which incorporates three-pole wigglers as radiation sources for the bending magnet beamlines. They are located in the short section between the M4 dipole and Q8 quadrupole magnets. Due to space constraints, a hybrid permanent magnet design is necessary to provide the required magnetic field strength. A three-pole wiggler with a flat peak field profile along the beam axis was designed to enhance the photon flux and flatten the transverse flux density distributions. The magnetic peak field at the center pole reached 1.08 Tesla for a magnetic gap of 26 mm. The maximum power density, integrated over all vertical angles, is 3.1 W/mm2, which is substantially higher than that of the existing bending magnets at the APS (0.86 W/mm2). Detailed designs of the three-pole wiggler is presented, including calculated spectral-angular flux distributions.

  12. Efficiency enhancement of a two-beam free-electron laser using a nonlinearly tapered wiggler

    Institute of Scientific and Technical Information of China (English)

    Maryam Zahedian; B.Maraghechi; M.H.Rouhani

    2012-01-01

    A nonlinear and non-averaged model of a two-beam free-electron laser (FEL) wiggler that is tapered nonlinearly in the absence of slippage is presented.The two beams are assumed to have different energies,and the fundamental resonance of the higher energy beam is at the third harmonic of the lower energy beam.By using Maxwell's equations and the full Lorentz force equation of motion for the electron beams,coupled differential equations are derived and solved numerically by the fourth-order Runge-Kutta method.The amplitude of the wiggler field is assumed to decrease nonlinearly when the saturation of the third harmonic occurs.By simulation,the optimum starting point of the tapering and the slopes for reducing the wiggler amplitude are found.This technique can be applied to substantially improve the efficiency of the two-beam FEL in the XUV and X-ray regions.The effect of tapering on the dynamical stability of the fast electron beam is also studied.

  13. X-ray lithography using wiggler and undulator synchrotron-radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    Neureuther, A.R.; Kim, K.J.; Thompson, A.C.; Hoyer, E.

    1983-08-01

    A systems design approach is used to identify feasible options for wiggler and undulator beam lines for x-ray lithography in the 0.5 to 0.2 ..mu..m linewidth region over 5 cm by 5 cm fields. Typical parameters from the Wiggler and Undulator in the Advanced Light Source designed at the Lawrence Berkeley Laboratory are used as examples. Moving from the conventional wavelengths of 4 to 9 A to very soft wavelengths around 15 A is shown to be very promising. The mask absorber thickness can be reduced a factor of three so that 0.2 ..mu..m features can be made with a 1:1 mask aspect ratio. The mask heating limited exposure time is also reduced a factor of three to 3 sec/cm/sup 2/. However, extremely thin beam line windows (1/4 mil Be) and mask supports (1 ..mu..m Si) must be used. A wiggler beam line design using a small slit window at a scanning mirror appears feasible. A unconventional, windowless differentially pumped beam line with dual deflecting mirrors could be used with an undulator source.

  14. The DEPFET detector-amplifier structure for spectroscopic imaging in astronomy and for experiments at free electron lasers

    Science.gov (United States)

    Lutz, G.; Aschauer, S.; Majewski, P.; Holl, P.; Strüder, L.

    2017-02-01

    The DEPFET detector-amplifier structure possesses several unique properties which make it extremely useful as readout element in semiconductor detectors and in particular as building block of semiconductor pixel detectors. Variations of DEPFETs can be tuned to specific requirements as to be sensitive only in predetermined time intervals, to measure signal charge with sub-electron precision, dead-time-free readout and with signal compression. These devices have been shown to work in simulations and in prototypes. Recently the first two fully developed detector systems have been finished and installed in the MIXS (Mercury Image X-ray Spectrometer) instrument of the Mercury Planetary Orbiter scheduled to be launched in 2017. A further DEPFET detector system under development is the DSSC (Depfet Sensor with Signal Compression) that will be installed in one of the beam-lines of XFEL. The requirements of the two projects are rather different. While the MIXS sensors are supposed to measure precisely the energy and position of single photons down to very low energies but at moderate rates, the DSSC has to measure the number of photons arriving in each pixel within a time interval of 220 ns. Here the challenge is the capability of detecting single X-ray photons in one pixel simultaneously with up to 10,000 photons in some other pixels. Device functioning has been verified with sensors produced in a research laboratory. Now process and design have been adapted to an industrial type production line, allowing additional improvements.

  15. First lasing of a high-gain harmonic generation free- electron laser experiment

    CERN Document Server

    Yu, L H; Ben-Zvi, I; Di Mauro, Louis F; Doyuran, A; Graves, W; Johnson, E; Krinsky, S; Malone, R; Pogorelsky, I V; Skaritka, J; Rakowsky, G; Solomon, L; Wang, X J; Woodle, M; Yakimenko, V; Biedron, S G; Galayda, J N; Gluskin, E; Jagger, J; Sajaev, Vadim; Vasserman, I

    2000-01-01

    We report on the first lasing of a high-gain harmonic generation (HGHG) free-electron laser (FEL). The experiment was conducted at the Accelerator Test Facility (ATF) at Brookhaven National Laboratory (BNL). This is a BNL experiment in collaboration with the Advanced Photon Source (APS) at Argonne National Laboratory. A preliminary measurement gives a high-gain harmonic generation (HGHG) pulse energy that is 2x10 sup 7 times larger than the spontaneous radiation. In a purely self-amplified spontaneous emission (SASE) mode of operation, the signal was measured as 10 times larger than the spontaneous radiation in the same distance (approx 2 m) through the same wiggler. This means the HGHG signal is 2x10 sup 6 times larger than the SASE signal. To obtain the same saturated output power by the SASE process, the radiator would have to be 3 times longer (6 m).

  16. Time-Dependent Simulation of Free-Electron Laser Amplifiers and Oscillators

    CERN Document Server

    Freund, H

    2005-01-01

    Time-dependent FEL simulations use a variety of techniques. Most simulations use a slowly varying envelope approximation (SVEA). One such technique assumes that the envelope varies only in z combined with a field representation as an ensemble of discrete harmonics, which is equivalent to a time-dependent simulation [1] but is computationally prohibitive. A second technique uses an SVEA in both in z and t [2]. The particles and fields are advanced in z using the same process as in steady-state simulations and then the time derivative describing slippage is applied. This is used in wiggler-averaged codes such as GINGER [3] and GENESIS [4]. We describe the inclusion of this technique in the non-wiggler-averaged code MEDUSA [5], which is applied to amplifiers and oscillators. MEDUSA differs from GINGER and GENESIS also in the way the field is treated. GINGER and GENESIS use a field solver and must explicitly propagate the field outside the wiggler oscillators. This is computationally intensive. MEDUSA uses a Gaus...

  17. Optimization of plasma amplifiers

    Science.gov (United States)

    Sadler, James D.; Trines, Raoul M. Â. G. Â. M.; Tabak, Max; Haberberger, Dan; Froula, Dustin H.; Davies, Andrew S.; Bucht, Sara; Silva, Luís O.; Alves, E. Paulo; Fiúza, Frederico; Ceurvorst, Luke; Ratan, Naren; Kasim, Muhammad F.; Bingham, Robert; Norreys, Peter A.

    2017-05-01

    Plasma amplifiers offer a route to side-step limitations on chirped pulse amplification and generate laser pulses at the power frontier. They compress long pulses by transferring energy to a shorter pulse via the Raman or Brillouin instabilities. We present an extensive kinetic numerical study of the three-dimensional parameter space for the Raman case. Further particle-in-cell simulations find the optimal seed pulse parameters for experimentally relevant constraints. The high-efficiency self-similar behavior is observed only for seeds shorter than the linear Raman growth time. A test case similar to an upcoming experiment at the Laboratory for Laser Energetics is found to maintain good transverse coherence and high-energy efficiency. Effective compression of a 10 kJ , nanosecond-long driver pulse is also demonstrated in a 15-cm-long amplifier.

  18. Construction and Analysis of Bio-amplifier Experiment System%生物电放大器实验系统的构建与分析

    Institute of Scientific and Technical Information of China (English)

    郝丽俊; 莫国民; 董冠群

    2012-01-01

    Objective To design a small experiment system for bio- amplifier. Methods The core circuit for the system was constructed using AD8132、AD620 and TLP512-1. Results Input impedance was more than 10 GΩ, the common-code rejection ratio(CMRR) was more than 80 dB, the upper cut-off frequency was 55.3Hz and the upper cut-off frequency was 44.5Hz for the 50Hz trap filter. Conclusion The experiment system has the characters of high CMRR、high input impedance and being easy to measure, which is helpful for the students to study bio -amplifier. [Chinese Medical Equipment Journal, 2011,33(1):16-18,46]%目的:设计一种小型的生物电隔离放大器实验系统.方法:应用AD8132、AD620、TLP512-1等构成放大电路的核心部分.结果:输入阻抗大于10 GΩ;共模抑制比>80 dB;50 Hz陷波电路的上限截止频率为55.3 Hz,下限截止频率为44.5 Hz.结论:实验系统具有高输入阻抗、高共模抑制比等特点,便于测量,有助于学生对生物电放大器的学习.

  19. Soft x-ray circular dichroism and scattering using a modulated elliptically polarizing wiggler and double synchronous detection

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, J.C.; Polewski, K.; Monteleone, D.C. [and others

    1998-01-23

    We have constructed an experimental station (beamline) at the National Synchrotron Light Source to measure circular dichroism (CD) using soft x-rays (250 {le} hv {le} 900 eV) from a time modulated elliptically polarizing wiggler. The polarization of the soft x-ray beam switches periodically between two opposite polarizations, hence permitting the use of phase-sensitive (lock-in) detection. While the wiggler can be modulated at frequencies up to 100 Hz, switching transients limit the actual practical frequency to {approx}25 Hz. With analog detection, switching transients are blocked by a chopper synchronized to the frequency and phase of the wiggler. The CD is obtained from the ratio of the signal recovered at the frequency of polarization modulation, f, to the average beam intensity, which is recovered by synchronous detection at frequency 2f.

  20. Enhanced x-rays from resonant betatron oscillations in laser wakefield with external wigglers

    Science.gov (United States)

    Zhang, Z. M.; Zhang, B.; Hong, W.; Yu, M. Y.; Deng, Z. G.; Teng, J.; He, S. K.; Gu, Y. Q.

    2016-11-01

    Generation of ultra-short betatron x-rays by laser-accelerated electron beams is of great research interest as it has many applications. In this paper, we propose a scheme for obtaining bright betatron x-rays by applying external wiggler magnetic field in the laser wakefield to resonantly drive the betatron oscillations of the accelerated electrons therein. This results in a significant enhancement of the betatron oscillation amplitude and generation of bright x-rays with high photon energy. The scheme is demonstrated using two-dimensional particle-in-cell simulation and discussed using a simple analytical model.

  1. Growth rate enhancement of free-electron laser by two consecutive wigglers with axial magnetic field

    Indian Academy of Sciences (India)

    A Hasanbeigi; A Farhadian; E Khademi Bidhendi

    2014-06-01

    The operative mechanism for a free-electron laser (FEL) with two consecutive helical wigglers having opposite circular polarization in the presence of an axial magnetic field is proposed and analysed. With the help of fluid theory, a tenth-degree polynomial dispersion equation for electromagnetic and space-charge waves is derived. The results are used to illustrate and discuss the dependence of growth rate on different system parameters. Finally, it is shown that for the same system parameters the growth rate of the proposed structure is more than the growth rate of instability in a conventional FEL.

  2. Modeling the effects of a flat wiggler on a storage ring beam

    Energy Technology Data Exchange (ETDEWEB)

    Helm, R.H.

    1978-06-01

    The purpose of the present note is to show how the various effects of the wiggler may be modeled in a simple way suitable for use in machine control. It will be seen that in general a total of about 17 functions are involved. However, in typical designs many of these functions vanish identically because of symmetries, and others are neglibly small. Furthermore, each of the functions may be modeled quite accurately by a single power law in (B/sub o//E)/sup n/ where B is a measure of the field excitation. E is the beam energy, and n is an integer which takes on values of either 0, 2, 3, 4, for 5 for the different functions. Magnet saturation may cause the field distribution to vary with excitation so that the series coefficients would vary slowly with B/sub o/. A computer program has been used to obtain numerical results for typical wiggler designs. In practice, the required functions could be determined either by computer analysis of the measured field data, or by experimental calibration using the stored beam in the ring. 9 refs., 3 figs., 11 tabs.

  3. Cross-differential amplifier

    Science.gov (United States)

    Hajimiri, Seyed-Ali (Inventor); Kee, Scott D. (Inventor); Aoki, Ichiro (Inventor)

    2013-01-01

    A cross-differential amplifier is provided. The cross-differential amplifier includes an inductor connected to a direct current power source at a first terminal. A first and second switch, such as transistors, are connected to the inductor at a second terminal. A first and second amplifier are connected at their supply terminals to the first and second switch. The first and second switches are operated to commutate the inductor between the amplifiers so as to provide an amplified signal while limiting the ripple voltage on the inductor and thus limiting the maximum voltage imposed across the amplifiers and switches.

  4. Portable musical instrument amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Christian, David E. (Danbury, CT)

    1990-07-24

    The present invention relates to a musical instrument amplifier which is particularly useful for electric guitars. The amplifier has a rigid body for housing both the electronic system for amplifying and processing signals from the guitar and the system's power supply. An input plug connected to and projecting from the body is electrically coupled to the signal amplifying and processing system. When the plug is inserted into an output jack for an electric guitar, the body is rigidly carried by the guitar, and the guitar is operatively connected to the electrical amplifying and signal processing system without use of a loose interconnection cable. The amplifier is provided with an output jack, into which headphones are plugged to receive amplified signals from the guitar. By eliminating the conventional interconnection cable, the amplifier of the present invention can be used by musicians with increased flexibility and greater freedom of movement.

  5. Analysis and Design of Backing Beam for Multipole Wiggler (MPW14) at PLS

    CERN Document Server

    Lee, Hong-Gi; Jung, Young-Gyu; Park, Ki-Hyeon; Sik Han, Hong; Suck Suh, Hyung; Wha Chung, Chin; Woo Lee, Wol

    2005-01-01

    Pohang Accelerator Laboratory (PAL) had developed and installed a Multipole Wiggler (MPW14) to utilize high energy synchrotron radiation at Pohang Light Source (PLS). The MPW14 is a hybrid type device with period of 14 cm, minimum gap of 14 mm, maximum flux density of 2.02 Tesla and total magnetic structure length of 2056 mm. The support locations and structure of an insertion device are optimized to achieve a minimum deflection due to the magnetic loads. A Finite Element Analysis (FEA) is performed to find out the amount of maximum deflection and optimal support positions on the backing beam, the support and drive structures of the MPW14 under expected magnetic load of 14 tons. To reduce the deflection effect further, two springs are designed and installed to compensate the gap dependent magnetic loads. The optimized deflection is estimated to be about 20.6 ? while the deflection before optimization is 238 ?.

  6. Theory of nonlinear harmonic generation in free-electron lasers with helical wigglers

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, G.; Saldin, E.; Schneidmiller, E.; Yurkov, M.

    2007-05-15

    CoherentHarmonicGeneration (CHG), and in particularNonlinearHarmonicGeneration (NHG), is of importance for both short wavelength Free-Electron Lasers (FELs), in relation with the achievement of shorter wavelengths with a fixed electron-beam energy, and high-average power FEL resonators, in relation with destructive effects of higher harmonics radiation on mirrors. In this paper we present a treatment of NHG from helical wigglers with particular emphasis on the second harmonic. Our study is based on an exact analytical solution of Maxwell's equations, derived with the help of a Green's function method. In particular, we demonstrate that nonlinear harmonic generation (NHG) fromhelicalwigglers vanishes on axis. Our conclusion is in open contrast with results in literature, that include a kinematical mistake in the description of the electron motion. (orig.)

  7. Considerations for NSLS-II Synchrotron Radiation Protection When Operating Damping Wigglers at Low Machine Energy

    Energy Technology Data Exchange (ETDEWEB)

    Seletskiy, S. [Brookhaven National Lab. (BNL), Upton, NY (United States). Photon Sciences Dept.; Podobedov, B. [Brookhaven National Lab. (BNL), Upton, NY (United States). Photon Sciences Dept.

    2015-12-30

    The NSLS-II storage ring vacuum chamber, including frontends (FE) and beamlines (BL), is protected from possible damage from synchrotron radiation (SR) emitted from insertion devices (IDs) by a dedicated active interlock system (AIS). The system monitors electron beam position and angle and triggers a beam dump if the beam orbit is outside of the active interlock envelope (AIE). The AIE was calculated under the assumptions of 3 GeV beam energy and ID gaps set to their minimum operating values (i.e. “fully closed”). Recently it was proposed to perform machine studies that would ramp the stored beam energy significantly below the nominal operational value of 3 GeV. These studies may potentially include the use of NSLS-II damping wigglers (DWs) for electron beam emittance reduction and control.

  8. Off-Axis Orbits in Realistic Helical Wigglers Fixed Points and Time Averaged Dynamical Variables

    CERN Document Server

    ThomasDonohue, John

    2004-01-01

    Many years ago Fajans, Kirkpatrick and Bekefi studied off-axis orbits in a realistic helical wiggler, both experimentally and theoretically. They found that as the distance from the axis of symmetry to the guiding center increased, both the mean axial velocity and the precession frequency of the guiding center varied. . They proposed a clever semi-empirical model which yielded an excellent description of both these variations. We point out that a approximate model proposed by us several years ago can be made to predict these delicate effects correctly, provided we extend our truncated quadratic Hamiltonian to include appropriate cubic terms. We develop an argument similar to the virial theorem to compare time averaged and fixed-point values of dynamical variables. Illustrative comparisons of our model with numerical calculation are presented.

  9. Modeling the emission of high power terahertz radiation using Langmuir wave as a wiggler

    Science.gov (United States)

    Panwar, Jyotsna; Sharma, Suresh C.

    2017-08-01

    The emission of high power terahertz (THz) radiation lying in the range of millimeter to submillimeter wavelengths has been studied analytically using the Langmuir wave as an electrostatic pump wave in the presence of static magnetic field for both finite and infinite geometries. The interaction of two laser beams with the relativistic electron beam leads to velocity modulation of the beam, which then translates into density modulation on traveling through the drift space. The premodulated beam on interacting with the pump wave acquires an oscillatory velocity that couples with the perturbed and modulated beam densities to result in nonlinear current density which helps in evaluating the growth rate and efficiency of the output THz radiation. The beam and plasma wave wiggler parameters are found to influence the growth rate and efficiency of the emitted THz radiation.

  10. Electron acceleration in the inverse free electron laser with a helical wiggler by axial magnetic field and ion-channel guiding

    Institute of Scientific and Technical Information of China (English)

    Reza Khazaeinezhad; Mahdi Esmaeilzadeh

    2012-01-01

    Electron acceleration in the inverse free electron laser (IFEL) with a helical wiggler in the presence of ion-channel guiding and axial magnetic field is investigated in this article.The effects of tapering wiggler amplitude and axial magnetic field are calculated for the electron acceleration.In free electron lasers,electron beams lose energy through radiation while in IFEL electron beams gain energy from the laser.The equation of electron motion and the equation of energy exchange between a single electron and electromagnetic waves are derived and then solved numerically using the fourth order Runge-Kutta method.The tapering effects of a wiggler magnetic field on electron acceleration are investigated and the results show that the electron acceleration increases in the case of a tapered wiggler magnetic field with a proper taper constant.

  11. The Conversion of CESR to Operate as the Test Accelerator, CesrTA, Part 4: Superconducting Wiggler Diagnostics

    CERN Document Server

    Billing, M G; Liu, X; Li, Y; Sabol, D; Smith, E N; Strohman, C R; Palmer, M A; Munson, D V

    2016-01-01

    Cornell's electron/positron storage ring (CESR) was modified over a series of accelerator shutdowns beginning in May 2008, which substantially improves its capability for research and development for particle accelerators. CESR's energy span from 1.8 to 5.6 GeV with both electrons and positrons makes it appropriate for the study of a wide spectrum of accelerator physics issues and instrumentation related to present light sources and future lepton damping rings. Additionally a number of these are also relevant for the beam physics of proton accelerators. This paper, the last in a series of four, describes the vacuum system modifications of the superconducting wigglers to accommodate the diagnostic instrumentation for the study of electron cloud (EC) behavior within wigglers. Earlier papers provided an overview of the accelerator physics program, the general modifications of CESR, the modifications of the vacuum system necessary for the conversion of CESR to the test accelerator, CesrTA, enhanced to study such ...

  12. Oscillators and operational amplifiers

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2005-01-01

    A generalized approach to the design of oscillators using operational amplifiers as active elements is presented. A piecewise-linear model of the amplifier is used so that it make sense to investigate the eigenvalues of the Jacobian of the differential equations. The characteristic equation...

  13. Thermal recovery of NIF amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Sutton, S.; Marshall, C.; Petty, C.; Smith, L.; van Wonterghem, B.; Mills, S.

    1997-02-01

    The issue of thermal recovery of the NIF amplifiers has taken on increased emphasis as program goals move toward increasing the shot rate to once every four hours. This paper addresses the technical issues associated with achieving thermal recovery in the NIF amplifiers. We identify two temperature related thermal recovery quantities: (1) the difference between the average slab temperature and the temperature of other surfaces in the amplifier cavity, and (2) the temperature difference in the slab over the aperture. The first quantity relates to optical disturbances in the gas column in the system, while the second quantity is associated with optical aberrations in the laser media itself. Calculations and experiments are used to quantify recovery criteria, and develop cooling approaches. The cooling approaches discussed are (1) active cooling of the flashlamps with ambient gas and chilled gas, and (2) active cooling of the slab edge cladding. Calculations indicate that the NIF baseline cooling approach of 20 cfm per lamp ambient temperature gas flow in both the central and side flashlamp cassettes is capable of meeting thermal recovery requirements for an 8 hour shot period, while to achieve a 4 hour shot period requires use of chilled gas and edge cladding cooling. In addition, the effect of changing the amplifier cavity and beamtube fill gas from nitrogen to helium is addressed, showing that a factor of 8 reduction in the sensitivity to thermal disturbances is possible. 6 refs., 9 figs., 1 tab.

  14. Microwave parametric amplifiers using externally pumped Josephson junctions

    DEFF Research Database (Denmark)

    Sørensen, O. H.; Mygind, Jesper; Pedersen, Niels Falsig

    1978-01-01

    Externally pumped parametric amplifiers are discussed. Theory and experiments on the singly degenerate parametric amplifier based on a Josephson junction are presented. Advantages and limitations of the singly degenerate and doubly degenerate parametric amplifiers are discussed. Some plans and pr...... and proposals for future research are presented....

  15. Auto-Zero Differential Amplifier

    Science.gov (United States)

    Quilligan, Gerard T. (Inventor); Aslam, Shahid (Inventor)

    2017-01-01

    An autozero amplifier may include a window comparator network to monitor an output offset of a differential amplifier. The autozero amplifier may also include an integrator to receive a signal from a latched window comparator network, and send an adjustment signal back to the differential amplifier to reduce an offset of the differential amplifier.

  16. Subacute neuropathological effects of microplanar beams of x-rays from a synchrotron wiggler.

    Science.gov (United States)

    Slatkin, D N; Spanne, P; Dilmanian, F A; Gebbers, J O; Laissue, J A

    1995-09-12

    Microplanar beam radiation therapy has been proposed to treat brain tumors by using a series of rapid exposures to an array of parallel x-ray beams, each beam having uniform microscopic thickness and macroscopic breadth (i.e., microplanar). Thirty-six rats were exposed head-on either to an upright 4-mm-high, 20- or 37-microns-wide beam or to a horizontal 7-mm-wide, 42-microns-high beam of mostly 32- to 126-keV, minimally divergent x-rays from the X17 wiggler at the National Synchrotron Light Source at Brookhaven National Laboratory. Parallel slices of the head, separated at either 75 or 200 microns on center, were exposed sequentially at 310-650 grays (Gy) per second until each skin-entrance absorbed dose reached 312, 625, 1250, 2500, 5000, or 10,000 Gy. The rats were euthanized 2 weeks or 1 month later. Two rats with 10,000-Gy-entrance slices developed brain tissue necrosis. All the other 10,000- and 5000-Gy-entrance slices and some of the 2500- and 1250-Gy-entrance slices showed loss of neuronal and astrocytic nuclei and their perikarya. No other kind of brain damage was evident histologically in any rat with entrance absorbed doses beam radiation therapy for brain tumors.

  17. 3 kA Power Supplies for the Duke OK-5 FEL Wigglers

    CERN Document Server

    Popov, Victor; Mikhailov, Stepan; Oakeley, Owen; Wallace, Patrick W; Wu, Y K

    2005-01-01

    The next generation electromagnetic OK-5/Duke storage ring FEL wigglers require three 3kA/70V power supplies with current stability about 20 ppm and current ripples less than 20ppm in their full operating range. Duke FEL Laboratory acquired three out-of-service thyristor controllable power supplies (Transrex, 5kA/100V) which was built almost 30 years ago. The existing archaic firing circuit, lack of any output voltage filtering and outdated DCCT, would not be able to meet the above requirements.To deliver the desirable high performance with very limited funds, all three T-Rex power supplies have been completely rebuilt in house at DFELL. Modern high stability electronic components and a Danfysik DCCT with a high current stability have been used. New symmetrical firing circuit, efficient passive LC filter and reliable transformer-coupled active filter are used to reduce output current ripples to an appropriate level. At the present time, the first refurbished power supply in operation since August, 2004 with g...

  18. High power Ka band TWT amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Golkowski, C.; Ivers, J.D.; Nation, J.A.; Wang, P.; Schachter, L.

    1999-07-01

    Two high power 35 GHz TWT amplifiers driven by a relativistic pencil, 850 kV, 200A electron beam have been assembled and tested. The first had a dielectric slow wave structure and was primarily used to develop diagnostics, and to gain experience in working with high power systems in Ka band. The source of the input power for the amplifier was a magnetron producing a 30 kW, 200ns long pulse of which 10 kW as delivered to the experiment. The 30 cm long dielectric (Teflon) amplifier produced output power levels of about 1 MW with a gain of about 23 dB. These results are consistent with expectations from PIC code simulations for this arrangement. The second amplifier, which is a single stage disk loaded slow wave structure, has been designed. It consists of one hundred uniform cells with two sets of ten tapered calls at the ends to lower the reflection coefficient. The phase advance per cell is {pi}/2. The amplifier passband extends from 28 to 40 GHz. It is designed to increase the output power to about 20 MW. The amplifier is in construction and will be tested in the near future. Details of the design of both systems will be provided and initial results from the new amplifier presented.

  19. Optoisolators simplify amplifier design

    Science.gov (United States)

    Ting, Joseph Wee

    2007-09-01

    Simplicity and low parts count are key virtues to this high voltage amplifier. Optoisolators replace complex high voltage transistor biasing schemes. This amplifier employs only 2 optoisolators, 16 high voltage mosfets transistors, 2 low voltage ones, 6 linear IC's and a score of passive components. Yet it can amplify opamp signals to 5 kV peak-to-peak from DC to sine waves up to 20 kHz. Resistor feedback guarantees the fidelity of the signal. It can source and sink 10 mA of output current. This amplifier was conceived to power ion traps for biological whole cell mass measurements. It is a versatile tool for a variety of applications.

  20. Charge-sensitive amplifier

    Directory of Open Access Journals (Sweden)

    Startsev V. I.

    2008-02-01

    Full Text Available The authors consider design and circuit design techniques of reduction of the influence of the pyroelectric effect on operation of the charge sensitive amplifiers. The presented experimental results confirm the validity of the measures taken to reduce the impact of pyroelectric currents. Pyroelectric currents are caused by the influence of the temperature gradient on the piezoelectric sensor and on the output voltage of charge sensitive amplifiers.

  1. RF Power Amplifier Analysis

    Directory of Open Access Journals (Sweden)

    M. Lokay

    1993-04-01

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

  2. Self-focusing property of a laser beam interacting with a lattice of nanoparticles in the presence of a planar magnetostatic wiggler

    Science.gov (United States)

    Esmaeildoost, N.; Zolghadr, S. H.; Jafari, S.

    2017-03-01

    In this paper, we study the nonlinear interaction of a laser beam with a periodic lattice of nanoparticles in the presence of a planar magnetostatic wiggler. The static magnetic field of the wiggler can couple with the electric field of the laser wave and change the electric field intensity of the pumped wave, leading to the formation of a nonlinear force. In consequence, the nonlinear force enhances plasmonic oscillations of the electronic cloud of each nanoparticle causing electron density modulation, which improves self-focusing property of the laser beam propagating through a periodic lattice of nanoparticles. By manipulating a classical microscopic approach into plasmonic oscillations of electronic clouds of the nanoparticles and the well-known perturbative method, a nonlinear dispersion relation describing the evolution of the laser amplitude propagating through the nanoparticle lattice has been obtained. The effect of the wiggler magnetic strength on the evolution of the laser transverse profile has been discussed. It was found that by increasing the wiggler strength, the transverse profile bandwidth shrinks and laser focusing is enhanced. In addition, further numerical results indicated that by increasing the wiggler field strength, the cut-off frequency of the body waves increases.

  3. Electric-Wiggler-Enhanced Three-Quantum Scattering and the Output Power Affected by this Scattering in a Free-Electron Laser

    Institute of Scientific and Technical Information of China (English)

    S. H. Kim

    2009-01-01

    We derive the cross section of scattering through the three-quantum interaction of an electron with the incident laser field, the emitted photon, and an axial electrostatic field produced by the magnetic wiggler in the magnetic wiggler acting as the sole zeroth-order perturbing classical field in the first free-electron laser (FEL). In the derivation, we apply quantum-wiggler electrodynamics (QWD). We find that this scattering predominates the usual two-quantum scattering. The output power of spontaneous free-electron two-quantum Stark emission driven by the above electrostatic field attenuated by the three-quantum scattering agrees within a factor of 10 with the measured power in the case of the first FEL.

  4. Electrospun amplified fiber optics.

    Science.gov (United States)

    Morello, Giovanni; Camposeo, Andrea; Moffa, Maria; Pisignano, Dario

    2015-03-11

    All-optical signal processing is the focus of much research aiming to obtain effective alternatives to existing data transmission platforms. Amplification of light in fiber optics, such as in Erbium-doped fiber amplifiers, is especially important for efficient signal transmission. However, the complex fabrication methods involving high-temperature processes performed in a highly pure environment slow the fabrication process and make amplified components expensive with respect to an ideal, high-throughput, room temperature production. Here, we report on near-infrared polymer fiber amplifiers working over a band of ∼20 nm. The fibers are cheap, spun with a process entirely carried out at room temperature, and shown to have amplified spontaneous emission with good gain coefficients and low levels of optical losses (a few cm(-1)). The amplification process is favored by high fiber quality and low self-absorption. The found performance metrics appear to be suitable for short-distance operations, and the large variety of commercially available doping dyes might allow for effective multiwavelength operations by electrospun amplified fiber optics.

  5. NINO an ultrafast low-power front-end amplifier discriminator for the time-of-flight detector in the ALICE experiment

    CERN Document Server

    Anghinolfi, F; Krummenacher, F; Usenko, E; Williams, M C S

    2004-01-01

    An ultrafast front-end preamplifier-discriminator chip called NINO has been developed for use in the ALICE time-of-flight detector. The chip has eight channels. Each channel is designed with an amplifier with less than 1-ns peaking time, a discriminator with a minimum detection threshold of 10 fC and an output stage. The output pulse has minimum time jitter (less than 25 ps) on the front edge, and the pulsewidth is dependent of the input signal charge. Each channel consumes 27 mW, and the eight channels fit in a 2*4 mm/sup 2/ ASIC processed in IBM 0.25- mu m CMOS technology. (3 refs).

  6. Phase noise in RF and microwave amplifiers.

    Science.gov (United States)

    Boudot, Rodolphe; Rubiola, Enrico

    2012-12-01

    Understanding amplifier phase noise is a critical issue in many fields of engineering and physics, such as oscillators, frequency synthesis, telecommunication, radar, and spectroscopy; in the emerging domain of microwave photonics; and in exotic fields, such as radio astronomy, particle accelerators, etc. Focusing on the two main types of base noise in amplifiers, white and flicker, the power spectral density of the random phase φ(t) is Sφ(f) = b(0) + b(-1)/f. White phase noise results from adding white noise to the RF spectrum in the carrier region. For a given RF noise level, b(0) is proportional to the reciprocal of the carrier power P(0). By contrast, flicker results from a near-dc 1/f noise-present in all electronic devices-which modulates the carrier through some parametric effect in the semiconductor. Thus, b(-1) is a parameter of the amplifier, constant in a wide range of P(0). The consequences are the following: Connecting m equal amplifiers in parallel, b(-1) is 1/m times that of one device. Cascading m equal amplifiers, b(-1) is m times that of one amplifier. Recirculating the signal in an amplifier so that the gain increases by a power of m (a factor of m in decibels) as a result of positive feedback (regeneration), we find that b(-1) is m(2) times that of the amplifier alone. The feedforward amplifier exhibits extremely low b(-1) because the carrier is ideally nulled at the input of its internal error amplifier. Starting with an extensive review of the literature, this article introduces a system-oriented model which describes the phase flickering. Several amplifier architectures (cascaded, parallel, etc.) are analyzed systematically, deriving the phase noise from the general model. There follow numerous measurements of amplifiers using different technologies, including some old samples, and in a wide frequency range (HF to microwaves), which validate the theory. In turn, theory and results provide design guidelines and give suggestions for CAD and

  7. Fourier plane image amplifier

    Science.gov (United States)

    Hackel, L.A.; Hermann, M.R.; Dane, C.B.; Tiszauer, D.H.

    1995-12-12

    A solid state laser is frequency tripled to 0.3 {micro}m. A small portion of the laser is split off and generates a Stokes seed in a low power oscillator. The low power output passes through a mask with the appropriate hole pattern. Meanwhile, the bulk of the laser output is focused into a larger stimulated Brillouin scattering (SBS) amplifier. The low power beam is directed through the same cell in the opposite direction. The majority of the amplification takes place at the focus which is the fourier transform plane of the mask image. The small holes occupy large area at the focus and thus are preferentially amplified. The amplified output is now imaged onto the multichip module where the holes are drilled. Because of the fourier plane amplifier, only about 1/10th the power of a competitive system is needed. This concept allows less expensive masks to be used in the process and requires much less laser power. 1 fig.

  8. Fourier plane image amplifier

    Science.gov (United States)

    Hackel, Lloyd A.; Hermann, Mark R.; Dane, C. Brent; Tiszauer, Detlev H.

    1995-01-01

    A solid state laser is frequency tripled to 0.3 .mu.m. A small portion of the laser is split off and generates a Stokes seed in a low power oscillator. The low power output passes through a mask with the appropriate hole pattern. Meanwhile, the bulk of the laser output is focused into a larger stimulated Brillouin scattering (SBS) amplifier. The low power beam is directed through the same cell in the opposite direction. The majority of the amplification takes place at the focus which is the fourier transform plane of the mask image. The small holes occupy large area at the focus and thus are preferentially amplified. The amplified output is now imaged onto the multichip module where the holes are drilled. Because of the fourier plane amplifier, only .about.1/10th the power of a competitive system is needed. This concept allows less expensive masks to be used in the process and requires much less laser power.

  9. The conversion of CESR to operate as the test accelerator, CesrTA, Part 4: superconducting wiggler diagnostics

    Science.gov (United States)

    Billing, M. G.; Greenwald, S.; Liu, X.; Li, Y.; Sabol, D.; Smith, E. N.; Strohman, C. R.; Palmer, M. A.; Munson, D. V.; Suetsugu, Y.

    2016-10-01

    Cornell's electron/positron storage ring (CESR) was modified over a series of accelerator shutdowns beginning in May 2008, which substantially improves its capability for research and development for particle accelerators. CESR's energy span from 1.8 to 5.6 GeV with both electrons and positrons makes it appropriate for the study of a wide spectrum of accelerator physics issues and instrumentation related to present light sources and future lepton damping rings. Additionally a number of these are also relevant for the beam physics of proton accelerators. This paper, the last in a series of four, describes the vacuum system modifications of the superconducting wigglers to accommodate the diagnostic instrumentation for the study of electron cloud (EC) behavior within wigglers. Earlier papers provided an overview of the accelerator physics program, the general modifications of CESR, the modifications of the vacuum system necessary for the conversion of CESR to the test accelerator, CESRTA, enhanced to study such subjects as low emittance tuning methods, EC effects, intra-beam scattering, fast ion instabilities as well as general improvements to beam instrumentation. While the initial studies of CESRTA focussed on questions related to the International Linear Collider damping ring design, CESR is a very versatile storage ring, capable of studying a wide range of accelerator physics and instrumentation questions.

  10. Investigation on Satellite-borne High-power Solid-state Power Amplifier Technology and Experiment%星载高功率固态功放关键技术与实验研究

    Institute of Scientific and Technical Information of China (English)

    武小坡; 赵海洋; 奚松涛

    2014-01-01

    该文结合某星载集中式固态发射机的高功率固态功率放大器,从星载应用着手,重点从高功率密度热设计、微放电防护设计、电磁兼容性设计等方面介绍了星载高功率固态功放关键性技术的设计方法,并且通过相关的真空环境试验验证了功率放大器组件设计方法的正确性和真空环境适应性。%Based on the research and development efforts of satellite-borne lumped solid-state transmitters, the design of a satellite-borne high-power microwave amplifier module is introduced. Focusing on satellite-borne applications, aspects of the high-power density thermal design, multipactor proof design, EMC design and so on, which are critical technologies for a solid-state power amplifier, are discussed. Subsequently, experiments are used to verify the concept.

  11. Chopper amplifier circuit with CMOS switches and amplifier FETs

    NARCIS (Netherlands)

    Huijsing, J.H.; Bakker, A.

    1997-01-01

    Abstract of NL 1001231 (C2) The input voltage is fed to the inputs of an operational amplifier via a chopping reversal switchThe CMOS operational amplifier has a current source and a current mirror. The operational amplifier output is fed to an output circuit. The possible offset voltage is supp

  12. Three-dimensional, time-dependent simulation of a regenerative amplifier free-electron laser

    Science.gov (United States)

    Freund, H. P.; Nguyen, D. C.; Sprangle, P. A.; van der Slot, P. J. M.

    2013-01-01

    Free-electron lasers have been designed to operate over virtually the entire electromagnetic spectrum from microwaves through x rays and in a variety of configurations including amplifiers and oscillators. Oscillators typically operate in the low-gain regime where the full spectral width is (Δω/ω)≈1/Nw and the efficiency η≈1/(2.4Nw). Further, since a low-gain oscillator saturates when the gain compensates for losses in the resonator G=L/(1-L), this implies that the losses must be relatively small and the cavity Q must be relatively large. This imposes problems for high power oscillators because the high Q can result in mirror loading above the damage threshold, and in short-wavelength oscillators because sufficiently low loss resonators may not be possible at x-ray wavelengths. In contrast, regenerative amplifier FELs (RAFELs) employ high-gain wigglers that reach exponential gain and can operate with high loss (i.e., low Q) resonators. As such, RAFELs may be able to function at either high power levels or short wavelengths. In this paper, we describe a three-dimensional, time-dependent simulation of a RAFEL operating at a 2.2-μm wavelength, and show that its behavior differs substantially from that of low-gain oscillators, and is closer to that of self-amplified spontaneous radiation FELs in regard to spectral linewidth and extraction efficiency.

  13. Amplifying genetic logic gates.

    Science.gov (United States)

    Bonnet, Jerome; Yin, Peter; Ortiz, Monica E; Subsoontorn, Pakpoom; Endy, Drew

    2013-05-03

    Organisms must process information encoded via developmental and environmental signals to survive and reproduce. Researchers have also engineered synthetic genetic logic to realize simpler, independent control of biological processes. We developed a three-terminal device architecture, termed the transcriptor, that uses bacteriophage serine integrases to control the flow of RNA polymerase along DNA. Integrase-mediated inversion or deletion of DNA encoding transcription terminators or a promoter modulates transcription rates. We realized permanent amplifying AND, NAND, OR, XOR, NOR, and XNOR gates actuated across common control signal ranges and sequential logic supporting autonomous cell-cell communication of DNA encoding distinct logic-gate states. The single-layer digital logic architecture developed here enables engineering of amplifying logic gates to control transcription rates within and across diverse organisms.

  14. STABILIZED TRANSISTOR AMPLIFIER

    Science.gov (United States)

    Noe, J.B.

    1963-05-01

    A temperature stabilized transistor amplifier having a pair of transistors coupled in cascade relation that are capable of providing amplification through a temperature range of - 100 un. Concent 85% F to 400 un. Concent 85% F described. The stabilization of the amplifier is attained by coupling a feedback signal taken from the emitter of second transistor at a junction between two serially arranged biasing resistances in the circuit of the emitter of the second transistor to the base of the first transistor. Thus, a change in the emitter current of the second transistor is automatically corrected by the feedback adjustment of the base-emitter potential of the first transistor and by a corresponding change in the base-emitter potential of the second transistor. (AEC)

  15. Principal modes in fiber amplifiers

    CERN Document Server

    Fridman, Moti; Dubinskii, Mark; Friesem, Asher A; Davidson, Nir

    2010-01-01

    The dynamics of the state of polarization in single mode and multimode fiber amplifiers are presented. The experimental results reveal that although the state of polarizations at the output can vary over a large range when changing the temperatures of the fiber amplifiers, the variations are significantly reduced when resorting to the principal states of polarization in single mode fiber amplifiers and principal modes in multimode fiber amplifiers.

  16. Sample Environment in Experiments using X-Ray Synchrotron Radiation

    DEFF Research Database (Denmark)

    Buras, B

    1984-01-01

    Modern electron (positron) storage rings are able to emit very intense X-ray radiation with a continuous spectrum extending to 0.1 A, from bending magnets and insertion devices (wavelength shifters and multipole wigglers). It can be used directly for white beam experiments and/or for monochromati...

  17. Multiple pass laser amplifier system

    Science.gov (United States)

    Brueckner, Keith A.; Jorna, Siebe; Moncur, N. Kent

    1977-01-01

    A laser amplification method for increasing the energy extraction efficiency from laser amplifiers while reducing the energy flux that passes through a flux limited system which includes apparatus for decomposing a linearly polarized light beam into multiple components, passing the components through an amplifier in delayed time sequence and recombining the amplified components into an in phase linearly polarized beam.

  18. Radio Frequency Solid State Amplifiers

    CERN Document Server

    Jacob, J

    2015-01-01

    Solid state amplifiers are being increasingly used instead of electronic vacuum tubes to feed accelerating cavities with radio frequency power in the 100 kW range. Power is obtained from the combination of hundreds of transistor amplifier modules. This paper summarizes a one hour lecture on solid state amplifiers for accelerator applications.

  19. Polarization effect in parametric amplifier

    Institute of Scientific and Technical Information of China (English)

    Junhe Zhou; Jianping Chen; Xinwan Li; Guiling Wu; Yiping Wang

    2005-01-01

    @@ Polarization effect in parametric amplifiers is studied. Coupled equations are derived from the basic propagation equations and numerical solutions are given for both one-wavelength-pump and two-wavelengthpump systems. Several parametric amplifiers driven by pumps at one wavelength and two wavelengths are analyzed and the polarization independent parametric amplifier is proposed.

  20. Improved-Bandwidth Transimpedance Amplifier

    Science.gov (United States)

    Chapsky, Jacob

    2009-01-01

    The widest available operational amplifier, with the best voltage and current noise characteristics, is considered for transimpedance amplifier (TIA) applications where wide bandwidth is required to handle fast rising input signals (as for time-of-flight measurement cases). The added amplifier inside the TIA feedback loop can be configured to have slightly lower voltage gain than the bandwidth reduction factor.

  1. Electronic amplifiers for automatic compensators

    CERN Document Server

    Polonnikov, D Ye

    1965-01-01

    Electronic Amplifiers for Automatic Compensators presents the design and operation of electronic amplifiers for use in automatic control and measuring systems. This book is composed of eight chapters that consider the problems of constructing input and output circuits of amplifiers, suppression of interference and ensuring high sensitivity.This work begins with a survey of the operating principles of electronic amplifiers in automatic compensator systems. The succeeding chapters deal with circuit selection and the calculation and determination of the principal characteristics of amplifiers, as

  2. Implementation of ultrafast X-ray diffraction at the 1W2B wiggler beamline of Beijing Synchrotron Radiation Facility.

    Science.gov (United States)

    Sun, Da Rui; Xu, Guang Lei; Zhang, Bing Bing; Du, Xue Yan; Wang, Hao; Li, Qiu Ju; Zhou, Yang Fan; Li, Zhen Jie; Zhang, Yan; He, Jun; Yue, Jun Hui; Lei, Ge; Tao, Ye

    2016-05-01

    The implementation of a laser pump/X-ray probe scheme for performing picosecond-resolution X-ray diffraction at the 1W2B wiggler beamline at Beijing Synchrotron Radiation Facility is reported. With the hybrid fill pattern in top-up mode, a pixel array X-ray detector was optimized to gate out the signal from the singlet bunch with interval 85 ns from the bunch train. The singlet pulse intensity is ∼2.5 × 10(6) photons pulse(-1) at 10 keV. The laser pulse is synchronized to this singlet bunch at a 1 kHz repetition rate. A polycapillary X-ray lens was used for secondary focusing to obtain a 72 µm (FWHM) X-ray spot. Transient photo-induced strain in BiFeO3 film was observed at a ∼150 ps time resolution for demonstration.

  3. The analysis of single-electron orbits in a free electron laser based upon a rectangular hybrid wiggler

    Science.gov (United States)

    Kordbacheh, A.; Ghahremaninezhad, Roghayeh; Maraghechi, B.

    2012-09-01

    A three-dimensional analysis of a novel free-electron laser (FEL) based upon a rectangular hybrid wiggler (RHW) is presented. This RHW is designed in a configuration composed of rectangular rings with alternating ferrite and dielectric spacers immersed in a solenoidal magnetic field. An analytic model of RHW is introduced by solution of Laplace's equation for the magnetostatic fields under the appropriate boundary conditions. The single-electron orbits in combined RHW and axial guide magnetic fields are studied when only the first and the third spatial harmonic components of the RHW field are taken into account and the higher order terms are ignored. The results indicate that the third spatial harmonic leads to group III orbits with a strong negative mass regime particularly in large solenoidal magnetic fields. RHW is found to be a promising candidate with favorable characteristics to be used in microwave FEL.

  4. Comparison of calculated brightness and flux of radiation from a long-period wiggler and a short-period undulator.

    Science.gov (United States)

    Shaftan, T; Hulbert, S L; Berman, L

    2008-07-01

    In this article the calculation of brightness and flux for two insertion devices of the 2.8 GeV X-ray storage ring at the NSLS is discussed. The radiation properties from the X25 linearly polarized wiggler and the new X25 short-period undulator are compared at a fixed photon energy (11.3 keV) corresponding to emission from the fifth harmonic of the short-period undulator. For this computation, three commonly available synchrotron radiation programs are used. The capabilities of each of these codes are briefly discussed, and their range of applicability are commented on. It is concluded that special care is needed when modeling the radiation of the classes of insertion devices considered here.

  5. Dispersion relation and growth rate for a corrugated channel free-electron laser with a helical wiggler pump

    Institute of Scientific and Technical Information of China (English)

    A.Hasanbeigi; H.Mehdian

    2013-01-01

    The effects of corrugated ion channels on electron trajectories and spatial growth rate for a free-electron laser with a one-dimensional helical wiggler have been investigated.Analysis of the steady-state electron trajectories is performed by solving the equations of motion.Our results show that the presence of a corrugated channel shifts the resonance frequency to smaller values of ion channel frequency.The sixth-order dispersion equation describing the coupling between the electrostatic beam mode and the electromagnetic mode has also been derived.The dispersion relation characteristic is analyzed in detail by numerical solution.Results show that the growth rate of instability in the presence of corrugated ion channels can be greatly enhanced relative to the case of an uniform ion channel.

  6. Wideband amplifier design

    CERN Document Server

    Hollister, Allen L

    2007-01-01

    In this book, the theory needed to understand wideband amplifier design using the simplest models possible will be developed. This theory will be used to develop algebraic equations that describe particular circuits used in high frequency design so that the reader develops a ""gut level"" understanding of the process and circuit. SPICE and Genesys simulations will be performed to show the accuracy of the algebraic models. By looking at differences between the algebraic equations and the simulations, new algebraic models will be developed that include parameters originally left out of the model

  7. Building valve amplifiers

    CERN Document Server

    Jones, Morgan

    2013-01-01

    Building Valve Amplifiers is a unique hands-on guide for anyone working with tube audio equipment--as an electronics hobbyist, audiophile or audio engineer. This 2nd Edition builds on the success of the first with technology and technique revisions throughout and, significantly, a major new self-build project, worked through step-by-step, which puts into practice the principles and techniques introduced throughout the book. Particular attention has been paid to answering questions commonly asked by newcomers to the world of the valve, whether audio enthusiasts tackling their first build or

  8. REGENERATIVE TRANSISTOR AMPLIFIER

    Science.gov (United States)

    Kabell, L.J.

    1958-11-25

    Electrical circults for use in computers and the like are described. particularly a regenerative bistable transistor amplifler which is iurned on by a clock signal when an information signal permits and is turned off by the clock signal. The amplifier porforms the above function with reduced power requirements for the clock signal and circuit operation. The power requirements are reduced in one way by employing transformer coupling which increases the collector circuit efficiency by eliminating the loss of power in the collector load resistor.

  9. Gain characteristics of a saturated fiber optic parametric amplifier

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Lorenzen, Michael Rodas; Noordegraaf, Danny

    2008-01-01

    In this work we discuss saturation performance of a fiber optic parametric amplifier. A simple numerical model is described and applied to specific cases. A system experiment using a saturated amplifier illustrates a 4 dB improvement in required signal to noise ratio for a fixed bit error ratio....

  10. Ultrafast Dynamics of Quantum-Dot Semiconductor Optical Amplifiers

    DEFF Research Database (Denmark)

    Poel, Mike van der; Hvam, Jørn Märcher

    2007-01-01

    We report on a series of experiments on the dynamical properties of quantum-dot semiconductor optical amplifiers. We show how the amplifier responds to one or several ultrafast (170 fs) pulses in rapid succession and our results demonstrate applicability and ultimate limitations to application...

  11. Nanoscale electromechanical parametric amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Aleman, Benjamin Jose; Zettl, Alexander

    2016-09-20

    This disclosure provides systems, methods, and apparatus related to a parametric amplifier. In one aspect, a device includes an electron source electrode, a counter electrode, and a pumping electrode. The electron source electrode may include a conductive base and a flexible conductor. The flexible conductor may have a first end and a second end, with the second end of the flexible conductor being coupled to the conductive base. A cross-sectional dimension of the flexible conductor may be less than about 100 nanometers. The counter electrode may be disposed proximate the first end of the flexible conductor and spaced a first distance from the first end of the flexible conductor. The pumping electrode may be disposed proximate a length of the flexible conductor and spaced a second distance from the flexible conductor.

  12. Nanoscale electromechanical parametric amplifier

    Science.gov (United States)

    Aleman, Benjamin Jose; Zettl, Alexander

    2016-09-20

    This disclosure provides systems, methods, and apparatus related to a parametric amplifier. In one aspect, a device includes an electron source electrode, a counter electrode, and a pumping electrode. The electron source electrode may include a conductive base and a flexible conductor. The flexible conductor may have a first end and a second end, with the second end of the flexible conductor being coupled to the conductive base. A cross-sectional dimension of the flexible conductor may be less than about 100 nanometers. The counter electrode may be disposed proximate the first end of the flexible conductor and spaced a first distance from the first end of the flexible conductor. The pumping electrode may be disposed proximate a length of the flexible conductor and spaced a second distance from the flexible conductor.

  13. Modeling of semiconductor optical amplifiers

    DEFF Research Database (Denmark)

    Mørk, Jesper; Bischoff, Svend; Berg, Tommy Winther

    We discuss the modelling of semiconductor optical amplifiers with emphasis on their high-speed properties. Applications in linear amplification as well as ultrafast optical signal processing are reviewed. Finally, the possible role of quantum-dot based optical amplifiers is discussed.......We discuss the modelling of semiconductor optical amplifiers with emphasis on their high-speed properties. Applications in linear amplification as well as ultrafast optical signal processing are reviewed. Finally, the possible role of quantum-dot based optical amplifiers is discussed....

  14. Breadboard Amplifier: Building and Using Simple Electrophysiology Equipment

    National Research Council Canada - National Science Library

    Crisp, Kevin M; Lin, Hunter; Prosper, Issa

    2016-01-01

    .... Here we describe a very simple electromyography (EMG) amplifier that can be built from scratch by students with no electronics experience in about 30 minutes, making it ideal for incorporating into a laboratory activity...

  15. Externally pumped millimeter-wave Josephson-junction parametric amplifier

    DEFF Research Database (Denmark)

    Levinsen, M.T; Pedersen, Niels Falsig; Sørensen, Ole;

    1980-01-01

    A unified theory of the singly and doubly degenerate Josephson-junction parametric amplifier is presented. Experiments with single junctions on both amplifier modes at frequencies 10, 35, and 70 GHz are discussed. Low-noise temperature (∼100 K, single sideband (SSB)) and reasonable gain (∼8 d......B) were obtained at 35 GHz in the singly degenerate mode. On the basis of the theory and experiments, a general procedure for optimizing junction parameters is discussed and illustrated by the specific design of a 100-GHz amplifier....

  16. Calibration setup for ultralow-current transresistance amplifiers

    CERN Document Server

    Finardi, Ilaria

    2016-01-01

    We describe a calibration setup for the transresistance of low-current amplifiers, based on the capacitance-charging method. The calibration can be performed in the current range of typical interest for electron counting experiments. The setup implementation is simple and rugged, and is suitable to be embedded in larger experiments where the amplifier is employed. The calibration is traceable to units of capacitance and of time. The base relative accuracy of the implementation is in the 10^-5 range.

  17. Wiggler Effects on the Growth Rate of a Raman Free-electron Laser with Axial Magnetic Field or Ion-Channel Guiding

    CERN Document Server

    Maraghechi, Behrouz

    2004-01-01

    A relativistic theory for Raman backscattering in the beam frame of electrons is presented and is used to find the growth rate of a free-electron laser (FEL), in the Raman regime. A one dimensional helical wiggler and an axial magnetic field are considered. The effects of static self-electric and self-magnetic fields, induced by the steady-state charge density and currents of the non-neutral electron beam, are taken into account to find the steady-state trajectories. The wiggler effects on the linear dispersion relations of the space-charge wave and radiation are included in the analysis. A numerical computation is conducted to compare the growth rate of the excited waves with nonrelativistic treatment. It was found that self-field effects increase the growth rate in the group II orbits and decrease it in the group I orbits. However, the wiggler effects on growth rate are stronger and increase the growth rate on both group I and group II orbits. The discontinuity, due to the cyclotron resonance with the radia...

  18. Chaotic behaviors of operational amplifiers.

    Science.gov (United States)

    Yim, Geo-Su; Ryu, Jung-Wan; Park, Young-Jai; Rim, Sunghwan; Lee, Soo-Young; Kye, Won-Ho; Kim, Chil-Min

    2004-04-01

    We investigate nonlinear dynamical behaviors of operational amplifiers. When the output terminal of an operational amplifier is connected to the inverting input terminal, the circuit exhibits period-doubling bifurcation, chaos, and periodic windows, depending on the voltages of the positive and the negative power supplies. We study these nonlinear dynamical characteristics of this electronic circuit experimentally.

  19. Dual-pump wave mixing in semiconductor optical amplifiers: performance enhancement with long amplifiers

    Science.gov (United States)

    Tomkos, Ioannis; Zacharopoulos, Ioannis; Syvridis, Dimitrios

    1999-05-01

    We demonstrate experimentally the improvement of the performance of the dual pump wave mixing scheme in semiconductor optical amplifiers, using long amplifier chips and high optical pump powers. The optical amplifiers used in the experiment had a ridge waveguide structure with bulk active layer and antireflective-coated angled facets. Measurements of the conversion efficiency and SBR as a function of wavelength shift are presented for a wavelength shift of more than 40 nm. The above measurements are carried out for three amplifier lengths (500 micrometers , 1000 micrometers , and 1500 micrometers ) and for different levels of the optical power of the two pumps. It will be shown that an increase in the amplifier length from 500 micrometers to 1500 micrometers results to an increase of more than 25 dB for the efficiency and more than 20 dB for the SBR. This improvement combined with the inherent advantages of the dual pump scheme (almost constant SBR and high efficiency for large wavelength shifts) results in a highly performing wavelength converter/phase conjugator, suitable for many applications.

  20. Implantable neurotechnologies: a review of integrated circuit neural amplifiers.

    Science.gov (United States)

    Ng, Kian Ann; Greenwald, Elliot; Xu, Yong Ping; Thakor, Nitish V

    2016-01-01

    Neural signal recording is critical in modern day neuroscience research and emerging neural prosthesis programs. Neural recording requires the use of precise, low-noise amplifier systems to acquire and condition the weak neural signals that are transduced through electrode interfaces. Neural amplifiers and amplifier-based systems are available commercially or can be designed in-house and fabricated using integrated circuit (IC) technologies, resulting in very large-scale integration or application-specific integrated circuit solutions. IC-based neural amplifiers are now used to acquire untethered/portable neural recordings, as they meet the requirements of a miniaturized form factor, light weight and low power consumption. Furthermore, such miniaturized and low-power IC neural amplifiers are now being used in emerging implantable neural prosthesis technologies. This review focuses on neural amplifier-based devices and is presented in two interrelated parts. First, neural signal recording is reviewed, and practical challenges are highlighted. Current amplifier designs with increased functionality and performance and without penalties in chip size and power are featured. Second, applications of IC-based neural amplifiers in basic science experiments (e.g., cortical studies using animal models), neural prostheses (e.g., brain/nerve machine interfaces) and treatment of neuronal diseases (e.g., DBS for treatment of epilepsy) are highlighted. The review concludes with future outlooks of this technology and important challenges with regard to neural signal amplification.

  1. Capacities of quantum amplifier channels

    Science.gov (United States)

    Qi, Haoyu; Wilde, Mark M.

    2017-01-01

    Quantum amplifier channels are at the core of several physical processes. Not only do they model the optical process of spontaneous parametric down-conversion, but the transformation corresponding to an amplifier channel also describes the physics of the dynamical Casimir effect in superconducting circuits, the Unruh effect, and Hawking radiation. Here we study the communication capabilities of quantum amplifier channels. Invoking a recently established minimum output-entropy theorem for single-mode phase-insensitive Gaussian channels, we determine capacities of quantum-limited amplifier channels in three different scenarios. First, we establish the capacities of quantum-limited amplifier channels for one of the most general communication tasks, characterized by the trade-off between classical communication, quantum communication, and entanglement generation or consumption. Second, we establish capacities of quantum-limited amplifier channels for the trade-off between public classical communication, private classical communication, and secret key generation. Third, we determine the capacity region for a broadcast channel induced by the quantum-limited amplifier channel, and we also show that a fully quantum strategy outperforms those achieved by classical coherent-detection strategies. In all three scenarios, we find that the capacities significantly outperform communication rates achieved with a naive time-sharing strategy.

  2. Design and analysis of the internally cooled silicon mirrors and benders for wiggler sources at the Advanced Photon Source

    Energy Technology Data Exchange (ETDEWEB)

    Schildkamp, W.; Jaski, Y. [Consortium for Advanced Radiation Sources, University of Chicago, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); Tonnessen, T.; Douglas, G. [Rocketdyne Albuquerque Operations, 2511 C. Broadbent Parkway, N.E., Albuquerque, NM 87107 (United States)

    1996-09-01

    When silicon single crystal mirrors are bent to cylindrical figures of typically 6 km bending radius, the moments needed are very small and easy to disturb by cooling attachments to the sides of the mirror. Hence, we decided to abandon the conventional concept of cooling plates attached to the sides of the mirrors and instead have chosen to use internal water channels. We present here the design of mirrors with cooling channels near the neutral axis of the silicon beam that have a rather thick {open_quote}{open_quote}hot wall.{close_quote}{close_quote} The results of this analytical work are nonintuitive, regarding the stresses produced by wiggler heating. The design path chosen minimizes figure errors due to coolant pressure variations and residual stresses from machining and bonding of multiple layers of silicon. The geometry of the water channels avoids water-to-vacuum seals and uses the mirror bender as the coolant manifold. Engineering efforts, which reduce the bending stresses at bender-to-silicon interface by a factor of five, will be presented. The complete mirror bender and motion control mechanics will be shown. {copyright} {ital 1996 American Institute of Physics.}

  3. Small signal microwave amplifier design

    CERN Document Server

    Grosch, Theodore

    2000-01-01

    This book explains techniques and examples for designing stable amplifiers for high-frequency applications in which the signal is small and the amplifier circuit is linear. An in-depth discussion of linear network theory provides the foundation needed to develop actual designs. Examples throughout the book will show you how to apply the knowledge gained in each chapter leading to the complex design of low noise amplifiers. Many exercises at the end of each chapter will help students to practice their skills. The solutions to these design problems are available in an accompanying solutions book

  4. International Standardization Activities for Optical Amplifiers

    Institute of Scientific and Technical Information of China (English)

    Haruo Okamura

    2003-01-01

    International standardization activities for Optical Amplifiers at IECTC86 and ITU-T SG15 are reviewed. Current discussions include Optical Amplifier safety guideline, Reliability standard, Rest methods of Noise and PMD, Definitions of Raman amplifier parameters and OA classification.

  5. Operational amplifiers theory and design

    CERN Document Server

    Huijsing, Johan

    2017-01-01

    This proven textbook guides readers to a thorough understanding of the theory and design of operational amplifiers (OpAmps). The core of the book presents systematically the design of operational amplifiers, classifying them into a periodic system of nine main overall configurations, ranging from one gain stage up to four or more stages. This division enables circuit designers to recognize quickly, understand, and choose optimal configurations. Characterization of operational amplifiers is given by macro models and error matrices, together with measurement techniques for their parameters. Definitions are given for four types of operational amplifiers depending on the grounding of their input and output ports. Many famous designs are evaluated in depth, using a carefully structured approach enhanced by numerous figures. In order to reinforce the concepts introduced and facilitate self-evaluation of design skills, the author includes problems with detailed solutions, as well as simulation exercises. Provides te...

  6. Characterization of SLUG microwave amplifiers

    Science.gov (United States)

    Hoi, I.-C.; Zhu, S.; Thorbeck, T.; McDermott, R.; Mutus, J.; Jeffrey, E.; Barends, R.; Chen, Y.; Roushan, P.; Fowler, A.; Sank, D.; White, T.; Campbell, B.; Chen, Z.; Chiaro, B.; Dunsworth, A.; Kelly, J.; Megrant, A.; Neill, C.; O'Malley, P. J. J.; Quintana, C.; Vainsencher, A.; Wenner, J.; Martinis, J. M.

    2015-03-01

    With the rapid growth of superconducting circuits quantum technology, a near quantum-limited amplifier at GHz frequency is needed to enable high fidelity measurements. We describe such an amplifier, the SQUID based, superconducting low inductance undulatory galvanometer (SLUG) amplifier. We measure the full scattering matrix of the SLUG. In particular, we measure both forward and reverse gain, as well as reflection. We see 15dB forward gain with added noise from one quanta to several quanta. The -1 dB compression point is around -95 dBm, about two orders of magnitude higher than that of typical Josephson parametric amplifiers. With these properties, SLUG is well suited for the high fidelity, simultaneous multiplexed readout of superconducting qubits.

  7. New Packaging for Amplifier Slabs

    Energy Technology Data Exchange (ETDEWEB)

    Riley, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thorsness, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Suratwala, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Steele, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Rogowski, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-03-18

    The following memo provides a discussion and detailed procedure for a new finished amplifier slab shipping and storage container. The new package is designed to maintain an environment of <5% RH to minimize weathering.

  8. A Transformer Class E Amplifier

    Directory of Open Access Journals (Sweden)

    Mikolajewski Miroslaw

    2014-12-01

    Full Text Available In a high-efficiency Class E ZVS resonant amplifier a matching and isolation transformer can replace some or even all inductive components of the amplifier thus simplifying the circuit and reducing its cost. In the paper a theoretical analysis, a design example and its experimental verification for a transformer Class E amplifier are presented. In the experimental amplifier with a transformer as the only inductive component in the circuit high efficiency ηMAX = 0.95 was achieved for supply voltage VI = 36 V, maximum output power POMAX = 100 W and the switching frequency f = 300 kHz. Measured parameters and waveforms showed a good agreement with theoretical predictions. Moreover, the relative bandwidth of the switching frequency was only 19% to obtain output power control from 4.8 W to POMAX with efficiency not less than 0.9 in the regulation range.

  9. PID Controller with Operational Amplifier

    Directory of Open Access Journals (Sweden)

    Cristian Paul Chioncel

    2009-01-01

    Full Text Available The paper presents a PID controller made with LM741 operational amplifier that implement the PID controllers laws and allow for a widerange of applications of in the field of automatic control of technicalprocesses and systems.

  10. A KIND OF NEW AMPLIFIER

    Institute of Scientific and Technical Information of China (English)

    YIN XUN-HE; FENG RU-PENG; REN YONG

    2000-01-01

    Chaotic characteristics in the iteration of logistic map (one-dimensional discrete dynamic system) are simulatedand analyzed. The circuit implementation of a kind of chaotic amplifier model is based on the chaotic characteristicsthat chaos is sensitively dependent on its initial conditions, and the circuit simulation result is given using simulationprogram with integrated circuit emphasis for personal computer (PSPICE), and is compared with linear amplifier.Advantages and disadvantages of such a model are indicated.

  11. Amplification Effect on Rayleigh Scattering and SBS in 25 km Distributed Fiber Raman Amplifier

    Institute of Scientific and Technical Information of China (English)

    Hua-Ping Gong; Zai-Xuan Zhang

    2008-01-01

    The amplification effect on stimulated Brillouin scattering (SBS) and Rayleigh scattering in the backward pumped G652 fibers Raman amplifier have been researched. The signal source is a tunable narrow spectral bandwidth (<10 MHz) ECL laser and is pumped by the tunable power 1427.2 nm fiber Raman laser. The Rayleigh scattering lines are amplified by fiber Raman amplifier, and Stokes stimulated Brillouin scattering lines are amplified by fiber Raman amplifier and fiber BriUouin amplifier. The SBS lines total gain is a production of the gain of Raman and the gain of Brillouin amplifier. In experiment, the gain of SBS is about 42 dB and the saturation gain of 25 km G652 backward FRA is about 25 dB, so the gain of fiber Brillouin amplifier is about 17 dB.

  12. EMI-resilient amplifier circuits

    CERN Document Server

    van der Horst, Marcel J; Linnenbank, André C

    2014-01-01

    This book enables circuit designers to reduce the errors introduced by the fundamental limitations and electromagnetic interference (EMI) in negative-feedback amplifiers.  The authors describe a systematic design approach for application specific negative-feedback amplifiers, with specified signal-to-error ratio (SER).  This approach enables designers to calculate noise, bandwidth, EMI, and the required bias parameters of the transistors used in  application specific amplifiers in order to meet the SER requirements.   ·         Describes design methods that incorporate electromagnetic interference (EMI) in the design of application specific negative-feedback amplifiers; ·         Provides designers with a structured methodology to avoid the use of trial and error in meeting signal-to-error ratio (SER) requirements; ·         Equips designers to increase EMI immunity of the amplifier itself, thus avoiding filtering at the input, reducing the number of components and avoiding detr...

  13. The effects of self-fields on the electron trajectory in a two-stream free electron laser with a helical wiggler and an axial guiding magnetic field

    Institute of Scientific and Technical Information of China (English)

    S. Saviz; E. Lashani; Farzin M. Aghamir

    2012-01-01

    A theory for the two-stream free-electron laser (TSFEL) with a helical wiggler and an axial guide magnetic field is developed.In the analysis,the effects of self-fields are taken into account.An analysis of the two-stream steady-state electron trajectories is given by solving the equation of motion.Numerical calculations show that there are seven groups of orbits in the presence of self-fields instead of two groups reported in the absence of self-fields.The stability of the trajectories is studied numerically.

  14. Limit circuit prevents overdriving of operational amplifier

    Science.gov (United States)

    Openshaw, F. L.

    1967-01-01

    Cutoff-type high gain amplifier coupled by a diode prevents overdriving of operational amplifier. An amplified feedback signal offsets the excess input signal that tends to cause the amplifier to exceed its preset limit. The output is, therfore, held to the set clamp level.

  15. Amplified graph C*-algebras

    CERN Document Server

    Eilers, Søren; Sørensen, Adam P W

    2011-01-01

    We provide a complete invariant for graph C*-algebras which are amplified in the sense that whenever there is an edge between two vertices, there are infinitely many. The invariant used is the standard primitive ideal space adorned with a map into {-1,0,1,2,...}, and we prove that the classification result is strong in the sense that isomorphisms at the level of the invariant always lift. We extend the classification result to cover more graphs, and give a range result for the invariant (in the vein of Effros-Handelman-Shen) which is further used to prove that extensions of graph C*-algebras associated to amplified graphs are again graph C*-algebras of amplified graphs.

  16. Capacitively-coupled chopper amplifiers

    CERN Document Server

    Fan, Qinwen; Huijsing, Johan H

    2017-01-01

    This book describes the concept and design of the capacitively-coupled chopper technique, which can be used in precision analog amplifiers. Readers will learn to design power-efficient amplifiers employing this technique, which can be powered by regular low supply voltage such as 2V and possibly having a +\\-100V input common-mode voltage input. The authors provide both basic design concepts and detailed design examples, which cover the area of both operational and instrumentation amplifiers for multiple applications, particularly in power management and biomedical circuit designs. Discusses basic working principles and details of implementation for proven designs; Includes a diverse set of applications, along with measurement results to demonstrate the effectiveness of the technique; Explains advantages and drawbacks of the technique, given particular circumstances.

  17. Coherent amplified optical coherence tomography

    Science.gov (United States)

    Zhang, Jun; Rao, Bin; Chen, Zhongping

    2007-07-01

    A technique to improve the signal-to-noise ratio (SNR) of a high speed 1300 nm swept source optical coherence tomography (SSOCT) system was demonstrated. A semiconductor optical amplifier (SOA) was employed in the sample arm to coherently amplify the weak light back-scattered from sample tissue without increasing laser power illuminated on the sample. The image quality improvement was visualized and quantified by imaging the anterior segment of a rabbit eye at imaging speed of 20,000 A-lines per second. The theory analysis of SNR gain is given followed by the discussion on the technologies that can further improve the SNR gain.

  18. Television-optical operational amplifier.

    Science.gov (United States)

    Goetz, J; Häusler, G; Sesselmann, R

    1979-08-15

    The advantages of negative feedback are well known in electronics and extensively used in the operational amplifier. The properties of such a system are nearly independent of the parameters in the forward branch of the system; they are only determined by external elements in the backward branch. An optical analog of such an operational amplifier is reported. The essential operations, amplifications, and inversion of the circulating signals are carried out using a TV system. The capability of the system to compensate for spatial inhomogeneities and for nonlinearities is demonstrated. In addition, the system is able to create the inverse of a transfer function located in the feedback branch.

  19. Dielectric waveguide amplifiers and lasers

    NARCIS (Netherlands)

    Pollnau, Markus

    The performance of semiconductor amplifiers and lasers has made them the preferred choice for optical gain on a micro-chip. In the past few years, we have demonstrated that also rare-earth-ion-doped dielectric waveguides show remarkable performance, ranging from a small-signal gain per unit length

  20. Amplification effect on SBS and Rayleigh scattering in the backward pumped distributed fiber Raman amplifier

    Institute of Scientific and Technical Information of China (English)

    Zaixuan Zhang; Huaping Gong

    2009-01-01

    The amplification effect on stimulated Brillouin scattering(SBS)and Rayleigh scattering in the backward pumped G652 fiber Raman amplifier(FRA)is studied.The pump source is a 1427.2-nm fiber Raman laser whose power is tunable between 0-1200 mW,and the signal source is a tunable narrow spectral bandwidth(<10 MHz)external cavity laser(ECL).The Rayleigh scattering lines are amplified by the FRA and Stokes SBS lines are amplified by the FRA and the fiber Brillouin amplifier.The total gain of SBS lines is the production of the gain of Raman amplifier and that of Brillouin amplifier.In experiment,the SBS gain is about 42 dB and the saturation gain of 25-km G652 backward FRA is about 25 dB,so the gain of fiber Brillouin amplifier is about 17 dB.

  1. Photonic-Band-Gap Traveling-Wave Gyrotron Amplifier

    Science.gov (United States)

    Nanni, E. A.; Lewis, S. M.; Shapiro, M. A.; Griffin, R. G.; Temkin, R. J.

    2014-01-01

    We report the experimental demonstration of a gyrotron traveling-wave-tube amplifier at 250 GHz that uses a photonic band gap (PBG) interaction circuit. The gyrotron amplifier achieved a peak small signal gain of 38 dB and 45 W output power at 247.7 GHz with an instantaneous −3 dB bandwidth of 0.4 GHz. The amplifier can be tuned for operation from 245–256 GHz. The widest instantaneous −3 dB bandwidth of 4.5 GHz centered at 253.25 GHz was observed with a gain of 24 dB. The PBG circuit provides stability from oscillations by supporting the propagation of transverse electric (TE) modes in a narrow range of frequencies, allowing for the confinement of the operating TE03-like mode while rejecting the excitation of oscillations at nearby frequencies. This experiment achieved the highest frequency of operation for a gyrotron amplifier; at present, there are no other amplifiers in this frequency range that are capable of producing either high gain or high output power. This result represents the highest gain observed above 94 GHz and the highest output power achieved above 140 GHz by any conventional-voltage vacuum electron device based amplifier. PMID:24476286

  2. Fiber optical parametric amplifiers in optical communication systems

    DEFF Research Database (Denmark)

    Marhic, Michel E.; Andrekson, Peter A.; Petropoulos, Periklis

    2015-01-01

    The prospects for using fiber optical parametric amplifiers (OPAs) in optical communication systems are reviewed. Phase-insensitive amplifiers (PIAs) and phase-sensitive amplifiers (PSAs) are considered. Low-penalty amplification at/or near 1 Tb/s has been achieved, for both wavelength- and time-...... in excess of 14,000 Tb/s x km in realistic wavelength-division multiplexed long-haul networks. Technical challenges remaining to be addressed in order for fiber OPAs to become useful for long-haul communication networks are discussed.......The prospects for using fiber optical parametric amplifiers (OPAs) in optical communication systems are reviewed. Phase-insensitive amplifiers (PIAs) and phase-sensitive amplifiers (PSAs) are considered. Low-penalty amplification at/or near 1 Tb/s has been achieved, for both wavelength- and time......-modulated signals. A PSA with 1.1-dB noise figure has been demonstrated, and preliminary wavelength-division multiplexing experiments have been performed with PSAs. 512Gb/s have been transmitted over 6,000km by periodic phase conjugation. Simulations indicate that PIAs could reach data rate x reach products...

  3. A CMOS current-mode operational amplifier

    DEFF Research Database (Denmark)

    Kaulberg, Thomas

    1993-01-01

    A fully differential-input, differential-output, current-mode operational amplifier (COA) is described. The amplifier utilizes three second-generation current conveyors (CCIIs) as the basic building blocks. It can be configured to provide either a constant gain-bandwidth product in a fully balanced...... current-mode feedback amplifier or a constant bandwidth in a transimpedance feedback amplifier. The amplifier is found to have a gain-bandwidth product of 3 MHz, an offset current of 0.8 μA (signal range ±700 μA), and a (theoretically) unlimited slew rate. The amplifier is realized in a standard CMOS 2...

  4. CMOS Current-mode Operational Amplifier

    DEFF Research Database (Denmark)

    Kaulberg, Thomas

    1992-01-01

    A fully differential-input differential-output current-mode operational amplifier (COA) is described. The amplifier utilizes three second generation current-conveyors (CCII) as the basic building blocks. It can be configured to provide either a constant gain-bandwidth product in a fully balanced...... current-mode feedback amplifier or a constant bandwidth in a transimpedance feedback amplifier. The amplifier is found to have a gain bandwidth product of 8 MHz, an offset current of 0.8 ¿A (signal-range ±700¿A) and a (theoretically) unlimited slew-rate. The amplifier is realized in a standard CMOS 2...

  5. Offering Students a Selection of Multiple Class B/AB Power Amplifiers as a Remote Laboratory

    National Research Council Canada - National Science Library

    Dag Andreas Hals Samuelsen; Olaf Hallan Graven

    2011-01-01

    In this paper a remote laboratory setup for conducting experiments on a class B/AB power amplifier is presented, addressing the problems related to running experiments requiring temperature matching...

  6. Single conversion stage amplifier - SICAM

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.

    2005-12-15

    This Ph.D. thesis presents a thorough analysis of the so called SICAM - SIngle Converter stage AMplifier approach to building direct energy conversion audio power amplifiers. The mainstream approach for building isolated audio power amplifiers today consists of isolated DC power supply and Class D amplifier, which essentially represents a two stage solution, where each of the components can be viewed as separate and independent part. The proposed SICAM solution strives for direct energy conversion from the mains to the audio output, by dedicating the operation of the components one to another and integrating their functions, so that the final audio power amplifier represents a single-stage topology with higher efficiency, lower volume, less board space, lower component count and subsequently lower cost. The SICAM approach is both applicable to non-isolated and isolated audio power amplifiers, but the problems encountered in these two cases are different. Non-isolated SICAM solutions are intended for both AC mains-connected and battery-powered devices. In non-isolated mains-connected SICAMs the main idea is to simplify the power supply or even provide integrated power factor correction (PFC) functions, while still maintaining low component stress and good audio performance by generally decreasing the input voltage level to the Class D audio power amplifier. On the other hand, non-isolated battery-powered SICAMs have to cope with the ever changing battery voltage and provide output voltage levels which are both lower and higher than the battery voltage, while still being simple and single-stage energy conversion solutions. In isolated SICAMs the isolation transformer adjusts the voltage level on the secondary side to the desired level, so the main challenges here are decreasing the size of the magnetic core and reducing the number and size of bulky reactive components as much as possible. The main focus of this thesis is directed towards the isolated SICAMs and

  7. Linearisation of RF Power Amplifiers

    DEFF Research Database (Denmark)

    Nielsen, Per Asbeck

    2001-01-01

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

  8. 338-GHz Semiconductor Amplifier Module

    Science.gov (United States)

    Samoska, Lorene A.; Gaier, Todd C.; Soria, Mary M.; Fung, King Man; Rasisic, Vesna; Deal, William; Leong, Kevin; Mei, Xiao Bing; Yoshida, Wayne; Liu, Po-Hsin; Uyeda, Jansen; Lai, Richard

    2010-01-01

    Research findings were reported from an investigation of new gallium nitride (GaN) monolithic millimeter-wave integrated circuit (MMIC) power amplifiers (PAs) targeting the highest output power and the highest efficiency for class-A operation in W-band (75-110 GHz). W-band PAs are a major component of many frequency multiplied submillimeter-wave LO signal sources. For spectrometer arrays, substantial W-band power is required due to the passive lossy frequency multipliers.

  9. Saturation properties of four-wave mixing between short optical pulses in semiconductor optical amplifiers

    DEFF Research Database (Denmark)

    Mørk, Jesper; Mecozzi, A.; Diez, S.

    1999-01-01

    Summary form only given. The authors report the first comparison between theory and experiment on the four wave mixing between trains of short pulses in semiconductor optical amplifiers. The theory is able to explain all qualitative features seen in the experiment.......Summary form only given. The authors report the first comparison between theory and experiment on the four wave mixing between trains of short pulses in semiconductor optical amplifiers. The theory is able to explain all qualitative features seen in the experiment....

  10. High power regenerative laser amplifier

    Science.gov (United States)

    Miller, J.L.; Hackel, L.A.; Dane, C.B.; Zapata, L.E.

    1994-02-08

    A regenerative amplifier design capable of operating at high energy per pulse, for instance, from 20-100 Joules, at moderate repetition rates, for instance from 5-20 Hertz is provided. The laser amplifier comprises a gain medium and source of pump energy coupled with the gain medium; a Pockels cell, which rotates an incident beam in response to application of a control signal; an optical relay system defining a first relay plane near the gain medium and a second relay plane near the rotator; and a plurality of reflectors configured to define an optical path through the gain medium, optical relay and Pockels cell, such that each transit of the optical path includes at least one pass through the gain medium and only one pass through the Pockels cell. An input coupler, and an output coupler are provided, implemented by a single polarizer. A control circuit coupled to the Pockels cell generates the control signal in timed relationship with the input pulse so that the input pulse is captured by the input coupler and proceeds through at least one transit of the optical path, and then the control signal is applied to cause rotation of the pulse to a polarization reflected by the polarizer, after which the captured pulse passes through the gain medium at least once more and is reflected out of the optical path by the polarizer before passing through the rotator again to provide an amplified pulse. 7 figures.

  11. Small and lightweight power amplifiers

    Science.gov (United States)

    Shams, Qamar A.; Barnes, Kevin N.; Fox, Robert L.; Moses, Robert W.; Bryant, Robert G.; Robinson, Paul C.; Shirvani, Mir

    2002-07-01

    The control of u wanted structural vibration is implicit in most of NASA's programs. Currently several approaches to control vibrations in large, lightweight, deployable structures and twin tail aircraft at high angles of attack are being evaluated. The Air Force has been examining a vertical tail buffet load alleviation system that can be integrated onboard an F/A-18 and flown. Previous wind tunnel and full-scale ground tests using distributed actuators have shown that the concept works; however, there is insufficient rom available onboard an F/A-18 to store current state-of- the-art system components such as amplifiers, DC-to-DC converter and a computer for performing vibration suppression. Sensor processing, power electronics, DC-to-DC converters, and control electronics that may be collocated with distributed actuators, are particularly desirable. Such electronic system would obviate the need for complex, centralized, control processing and power distribution components that will eliminate the weight associated with lengthy wiring and cabling networks. Several small and lightweight power amplifiers ranging from 300V pp to 650V pp have been designed using off the shelf components for different applications. In this paper, the design and testing of these amplifiers will be presented under various electrical loads.

  12. SPS RF System Amplifier plant

    CERN Multimedia

    1977-01-01

    The picture shows a 2 MW, 200 MHz amplifier plant with feeder lines. The main RF-system of the SPS comprises four cavities: two of 20 m length and two of 16.5 m length. They are all installed in one long straight section (LSS 3). These cavities are of the travelling-wave type operating at a centre frequency of 200.2 MHz. They are wideband, filling time about 700 ns and untuned. The power amplifiers, using tetrodes are installed in a surface building 200 m from the cavities. Initially only two cavities were installed, a third cavity was installed in 1978 and a forth one in 1979. The number of power amplifiers was also increased: to the first 2 MW plant a second 2 MW plant was added and by end 1979 there were 8 500 kW units combined in pairs to feed each of the 4 cavities with up to about 1 MW RF power, resulting in a total accelerating voltage of about 8 MV. See also 7412016X, 7412017X, 7411048X.

  13. Analog circuit design designing high performance amplifiers

    CERN Document Server

    Feucht, Dennis

    2010-01-01

    The third volume Designing High Performance Amplifiers applies the concepts from the first two volumes. It is an advanced treatment of amplifier design/analysis emphasizing both wideband and precision amplification.

  14. Higher order mode optical fiber Raman amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Friis, Søren Michael Mørk; Usuga Castaneda, Mario A.

    2016-01-01

    We review higher order mode Raman amplifiers and discuss recent theoretical as well as experimental results including system demonstrations.......We review higher order mode Raman amplifiers and discuss recent theoretical as well as experimental results including system demonstrations....

  15. Improved charge amplifier using hybrid hysteresis compensation

    Science.gov (United States)

    Amin-Shahidi, Darya; Trumper, David L.

    2013-08-01

    We present a novel charge amplifier, with a robust feedback circuit and a method for compensating piezoelectric actuator's hysteresis at low frequencies. The amplifier uses a modified feedback circuit which improves robustness to the addition of series load impedance such as in cabling. We also describe a hybrid hysteresis compensation method for enabling the charge amplifier to reduce hysteresis at low frequencies. Experimental results demonstrate the utility of the new amplifier design.

  16. European Research on THz Vacuum Amplifiers

    DEFF Research Database (Denmark)

    Brunetti, F.; Cojocarua, C.-S.; de Rossi, A.

    2010-01-01

    The OPTHER (OPtically Driven TeraHertz AmplifiERs) project represents a considerable advancement in the field of high frequency amplification. The design and realization of a THz amplifier within this project is a consolidation of efforts at the international level from the main players of the Eu...... of the European research, academy and industry in vacuum electronics. This paper describes the status of the project and progress towards the THz amplifier realization....

  17. Challenges in higher order mode Raman amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Nielsen, Kristian; Friis, Søren Michael Mørk;

    2015-01-01

    A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed......A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed...

  18. European Research on THz Vacuum Amplifiers

    DEFF Research Database (Denmark)

    Brunetti, F.; Cojocarua, C.-S.; de Rossi, A.

    2010-01-01

    The OPTHER (OPtically Driven TeraHertz AmplifiERs) project represents a considerable advancement in the field of high frequency amplification. The design and realization of a THz amplifier within this project is a consolidation of efforts at the international level from the main players of the Eu...... of the European research, academy and industry in vacuum electronics. This paper describes the status of the project and progress towards the THz amplifier realization....

  19. Challenges in higher order mode Raman amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Nielsen, Kristian; Friis, Søren Michael Mørk

    2015-01-01

    A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed......A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed...

  20. Visible-infrared self-amplified spontaneous emission amplifier free electron laser undulator

    Science.gov (United States)

    Carr, Roger; Cornacchia, Max; Emma, Paul; Nuhn, Heinz-Dieter; Poling, Ben; Ruland, Robert; Johnson, Erik; Rakowsky, George; Skaritka, John; Lidia, Steve; Duffy, Pat; Libkind, Marcus; Frigola, Pedro; Murokh, Alex; Pellegrini, Claudio; Rosenzweig, James; Tremaine, Aaron

    2001-12-01

    The visible-infrared self-amplified spontaneous emission amplifier (VISA) free electron laser (FEL) is an experimental device designed to show self-amplified spontaneous emission (SASE) to saturation in the near infrared to visible light energy range. It generates a resonant wavelength output from 800-600 nm, so that silicon detectors may be used to characterize the optical properties of the FEL radiation. VISA is designed to show how SASE FEL theory corresponds with experiment in this wavelength range, using an electron beam with emittance close to that planned for the future Linear Coherent Light Source at SLAC. VISA comprises a 4 m pure permanent magnet undulator with four 99 cm segments, each of 55 periods, 18 mm long. The undulator has distributed focusing built into it, to reduce the average beta function of the 70-85 MeV electron beam to about 30 cm. There are four FODO cells per segment. The permanent magnet focusing lattice consists of blocks mounted on either side of the electron beam, in the undulator gap. The most important undulator error parameter for a free electron laser is the trajectory walk-off, or lack of overlap of the photon and electron beams. Using pulsed wire magnet measurements and magnet shimming, we were able to control trajectory walk-off to less than +/-50 μm per field gain length.

  1. Visible-infrared self-amplified spontaneous emission amplifier free electron laser undulator

    Directory of Open Access Journals (Sweden)

    Roger Carr

    2001-12-01

    Full Text Available The visible-infrared self-amplified spontaneous emission amplifier (VISA free electron laser (FEL is an experimental device designed to show self-amplified spontaneous emission (SASE to saturation in the near infrared to visible light energy range. It generates a resonant wavelength output from 800–600 nm, so that silicon detectors may be used to characterize the optical properties of the FEL radiation. VISA is designed to show how SASE FEL theory corresponds with experiment in this wavelength range, using an electron beam with emittance close to that planned for the future Linear Coherent Light Source at SLAC. VISA comprises a 4 m pure permanent magnet undulator with four 99 cm segments, each of 55 periods, 18 mm long. The undulator has distributed focusing built into it, to reduce the average beta function of the 70–85 MeV electron beam to about 30 cm. There are four FODO cells per segment. The permanent magnet focusing lattice consists of blocks mounted on either side of the electron beam, in the undulator gap. The most important undulator error parameter for a free electron laser is the trajectory walk-off, or lack of overlap of the photon and electron beams. Using pulsed wire magnet measurements and magnet shimming, we were able to control trajectory walk-off to less than ±50 μm per field gain length.

  2. A High-performance Small Signal Amplifier

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    According to questions in the design of high quality small signal amplifier, this paper gave a new-type high performance small signal amplifier. The paper selected the operational amplifier of ICL Company and designed a new-type circuit with simple, low cost and excellent performance.

  3. low pump power photonic crystal fibre amplifiers

    DEFF Research Database (Denmark)

    Hougaard, Kristian G.; Broeng, Jes; Bjarklev, Anders Overgaard

    2003-01-01

    Designs of low pump power optical amplifiers, based on photonic crystal fibres are presented. The potential of these fibre amplifiers is investigated, and it is demonstrated that such amplifiers may deliver gains of more than 15 dB at 1550 nm with less than 1 mW of optical pump power....

  4. Remote Acquisition Amplifier For 50-Ohm Cable

    Science.gov (United States)

    Amador, Jose J.

    1995-01-01

    Buffer-amplifier unit designed to drive 50-Ohm cables up to 100 ft. (30 m) long, compensating for attenuation in cables and enabling remote operation of oscilloscopes. Variable resistor provides for adjustment of gain of amplifier, such that overall gain from input terminals of amplifier to output end of cable set to unity.

  5. Bio-isolated DC operational amplifier

    Science.gov (United States)

    Lee, R. D.

    1974-01-01

    Possibility of shocks from leakage currents can be reduced by use of isolated preamplifiers. Amplifier consists of battery-powered operational amplifier coupled by means of light-emitting diodes to another amplifier which may be grounded and operated from ac power mains or separate battery supply.

  6. Spatial and spectral imaging of LMA photonic crystal fiber amplifiers

    DEFF Research Database (Denmark)

    Laurila, Marko; Lægsgaard, Jesper; Alkeskjold, Thomas Tanggaard

    2011-01-01

    We demonstrate modal characterization using spatial and spectral resolved (S2) imaging, on an Ytterbium-doped large-mode-area photonic crystal fiber (PCF) amplifier and compare results with conventional cut-off methods. We apply numerical simulations and step-index fiber experiments to calibrate...

  7. An Implantable CMOS Amplifier for Nerve Signals

    DEFF Research Database (Denmark)

    Nielsen, Jannik Hammel; Lehmann, Torsten

    2003-01-01

    In this paper, a low noise high gain CMOS amplifier for minute nerve signals is presented. The amplifier is constructed in a fully differential topology to maximize noise rejection. By using a mixture of weak- and strong inversion transistors, optimal noise suppression in the amplifier is achieved....... A continuous-time current-steering offset-compensation technique is utilized in order to minimize the noise contribution and to minimize dynamic impact on the amplifier input nodes. The method for signal recovery from noisy nerve signals is presented. A prototype amplifier is realized in a standard digital 0...

  8. Log amplifier with pole-zero compensation

    Science.gov (United States)

    Brookshier, William

    1987-01-01

    A logarithmic amplifier circuit provides pole-zero compensation for improved stability and response time over 6-8 decades of input signal frequency. The amplifier circuit includes a first operational amplifier with a first feedback loop which includes a second, inverting operational amplifier in a second feedback loop. The compensated output signal is provided by the second operational amplifier with the log elements, i.e., resistors, and the compensating capacitors in each of the feedback loops having equal values so that each break point or pole is offset by a compensating break point or zero.

  9. Approaching Quantum-Limited Amplification with Large Gain Catalyzed by Optical Parametric Amplifier Medium

    Science.gov (United States)

    Zheng, Qiang; Li, Kai

    2017-07-01

    Amplifier is at the heart of experiments carrying out the precise measurement of a weak signal. An idea quantum amplifier should have a large gain and minimum added noise simultaneously. Here, we consider the quantum measurement properties of the cavity with the OPA medium in the op-amp mode to amplify an input signal. We show that our nonlinear-cavity quantum amplifier has large gain in the single-value stable regime and achieves quantum limit unconditionally. Supported by the National Natural Science Foundation of China under Grant Nos. 11365006, 11364006, and the Natural Science Foundation of Guizhou Province QKHLHZ [2015]7767

  10. High temperature charge amplifier for geothermal applications

    Science.gov (United States)

    Lindblom, Scott C.; Maldonado, Frank J.; Henfling, Joseph A.

    2015-12-08

    An amplifier circuit in a multi-chip module includes a charge to voltage converter circuit, a voltage amplifier a low pass filter and a voltage to current converter. The charge to voltage converter receives a signal representing an electrical charge and generates a voltage signal proportional to the input signal. The voltage amplifier receives the voltage signal from the charge to voltage converter, then amplifies the voltage signal by the gain factor to output an amplified voltage signal. The lowpass filter passes low frequency components of the amplified voltage signal and attenuates frequency components greater than a cutoff frequency. The voltage to current converter receives the output signal of the lowpass filter and converts the output signal to a current output signal; wherein an amplifier circuit output is selectable between the output signal of the lowpass filter and the current output signal.

  11. Audio power amplifier design handbook

    CERN Document Server

    Self, Douglas

    2013-01-01

    This book is essential for audio power amplifier designers and engineers for one simple reason...it enables you as a professional to develop reliable, high-performance circuits. The Author Douglas Self covers the major issues of distortion and linearity, power supplies, overload, DC-protection and reactive loading. He also tackles unusual forms of compensation and distortion produced by capacitors and fuses. This completely updated fifth edition includes four NEW chapters including one on The XD Principle, invented by the author, and used by Cambridge Audio. Cro

  12. Design and production of a new surface mount charge-integrating amplifier for CDF

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, C.; Drake, G.

    1991-01-01

    We present our experiences in designing and producing 26,000 new charge-integrating amplifiers for CDF, using surface-mount components. The new amplifiers were needed to instrument 920 new 24-channel CDF RABBIT boards, which are replacing an older design rendered obsolete by increases in the collision rate. Important design considerations were frequency response, physical size and cost. 5 refs.

  13. Modeling and optimization of magnetostrictive actuator amplified by compliant mechanism

    Science.gov (United States)

    Niu, Muqing; Yang, Bintang; Yang, Yikun; Meng, Guang

    2017-09-01

    Magnetostrictive actuators are commonly used in precision engineering with the advantages of high resolution and fast response. Their limited strokes are always amplified by compliant mechanisms without wear and backlash. This paper proposes a hybrid model for the actuation system considering the coupling of the actuator and the amplifier. The magnetostrictive model, based on the Jiles-Atherton model, is related to the input stiffness of the amplifier when quantifying the magneto-mechanical effects, including stress-dependent magnetization, stress-dependent magnetostriction and ΔE effect. The compliant mechanism model aims at constructing the flexibility matrix with the amplification ratio and input stiffness related to the spring factor of the load. The deformation and structural stress of the amplifier are also dependent on the output strain of magnetostrictive material. Experiments under both free load and spring load conditions have been done to verify the effectiveness of the hybrid model. The proposed model is suitable for parameter optimization and the performance indicators can be precisely quantified. Optimization based on hybrid model is more preferred than optimizing the actuator and amplifier independently for maximum output displacement. Furthermore, ‘stiffness match principle’ is no longer applicable when considering ΔE effect, and the optimal external stiffness problem can be numerically solved by the hybrid model for maximum output energy of magnetostrictive material.

  14. High power RF solid state power amplifier system

    Science.gov (United States)

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

    2011-01-01

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

  15. Bit rate and pulse width dependence of four-wave mixing of short optical pulses in semiconductor optical amplifiers

    DEFF Research Database (Denmark)

    Diez, S.; Mecozzi, A.; Mørk, Jesper

    1999-01-01

    We investigate the saturation properties of four-wave mixing of short optical pulses in a semiconductor optical amplifier. By varying the gain of the optical amplifier, we find a strong dependence of both conversion efficiency and signal-to-background ratio on pulse width and bit rate....... In particular, the signal-to-background ratio can be optimized for a specific amplifier gain. This behavior, which is coherently described in experiment and theory, is attributed to the dynamics of the amplified spontaneous emission, which is the main source of noise in a semiconductor optical amplifier....

  16. Quantum Noise in Amplifiers and Hawking/Dumb-Hole Radiation as Amplifier Noise

    CERN Document Server

    Unruh, W G

    2011-01-01

    The quantum noise in a linear amplifier is shown to be thermal noise. The theory of linear amplifiers is applied first to the simplest, single or double oscillator model of an amplifier, and then to linear model of an amplifier with continuous fields and input and outputs. Finally it is shown that the thermal noise emitted by black holes first demonstrated by Hawking, and of dumb holes (sonic and other analogs to black holes), arises from the same analysis as for linear amplifiers. The amplifier noise of black holes acting as amplifiers on the quantum fields living in the spacetime surrounding the black hole is the radiation discovered by Hawking. For any amplifier, that quantum noise is completely characterized by the attributes of the system regarded as a classical amplifier, and arises out of those classical amplification factors and the commutation relations of quantum mechanics.

  17. YANG-MILLS FIELD AMPLIFIER

    Directory of Open Access Journals (Sweden)

    Trunev A. P.

    2015-09-01

    Full Text Available The article presents a project of the Yang-Mills amplifier. Amplifier model is a multilayer spherical shell with increasing density towards the center. In the center of the amplifier is the core of high-density material. It is shown that in such a system, the amplitude of the Yang-Mills waves rises from the periphery to the center of several orders of magnitude. The role of the Yang-Mills field in the processes occurring in the nuclei of galaxies, stars and planets is discussed. The data modeling to strengthen the Yang-Mills field in the bowels of the planet, with an atomic explosion, and in some special devices such as the voltaic pile. To describe the mechanism of amplification chromodynamics field used as accurate results in Yang-Mills theory and numerical models developed based on an average and the exact equations as well. Among the exact solutions of the special role played by the centralsymmetric metric describing the contribution of the Yang-Mills field in the speed of recession of galaxies. Among the approximate numerical models can be noted the eight-scalar model we have developed for the simulation of non-linear color oscillations and chaos in the Yang-Mills theory. Earlier models were investigated spatio-temporal oscillations of the YangMills theory in the case of three and eight colors. The results of numerical simulation show that the nonlinear interaction does not lead to a spatial mixing of colors as it might be in the case of turbulent diffusion. Depending on the system parameters there is a suppression of the amplitude of the oscillations the first three by five colors or vice versa. The kinetic energy fluctuations or shared equally between the color components, or dominated by the kinetic energy of repressed groups of colors. In the present study, we found that amplification chromodynamic field leads to a sharp increase in the amplitude of the suppressed color, which can lead to an increase in entropy, excitation of nuclear

  18. Locoregional MYCN-amplified neuroblastoma.

    Science.gov (United States)

    Morales La Madrid, Andres; Volchenboum, Samuel; Gastier-Foster, Julie M; Pyatt, Robert; Liu, Don; Pytel, Peter; Lavarino, Cinzia; Rodriguez, Eva; Cohn, Susan L

    2012-10-01

    MYCN-amplification is strongly associated with other high-risk prognostic factors and poor outcome in neuroblastoma. Infrequently, amplification of MYCN has been identified in localized tumors with favorable biologic features. Outcome for these children is difficult to predict and optimal treatment strategies remain unclear. We report a 5-month-old who presented with an MYCN-amplified INSS stage 3, pelvic neuroblastoma. The tumor had favorable histology, hyperdiploidy, and lacked 1p36 and 11q23 aberrations. Although the patient met the criteria for high-risk neuroblastoma, because of the discordant prognostic markers we elected to treat her according to an intermediate-risk protocol. She remains event-free more than 18 months.

  19. Transverse pumped laser amplifier architecture

    Science.gov (United States)

    Bayramian, Andrew James; Manes, Kenneth; Deri, Robert; Erlandson, Al; Caird, John; Spaeth, Mary

    2013-07-09

    An optical gain architecture includes a pump source and a pump aperture. The architecture also includes a gain region including a gain element operable to amplify light at a laser wavelength. The gain region is characterized by a first side intersecting an optical path, a second side opposing the first side, a third side adjacent the first and second sides, and a fourth side opposing the third side. The architecture further includes a dichroic section disposed between the pump aperture and the first side of the gain region. The dichroic section is characterized by low reflectance at a pump wavelength and high reflectance at the laser wavelength. The architecture additionally includes a first cladding section proximate to the third side of the gain region and a second cladding section proximate to the fourth side of the gain region.

  20. Dynamics of Soliton Cascades in Fiber Amplifiers

    CERN Document Server

    Arteaga-Sierra, F R; Agrawal, Govind P

    2016-01-01

    We study numerically the formation of cascading solitons when femtosecond optical pulses are launched into a fiber amplifier with less energy than required to form a soliton of equal duration. As the pulse is amplified, cascaded fundamental solitons are created at different distances, without soliton fission, as each fundamental soliton moves outside the gain bandwidth through the Raman-induced spectral shifts. As a result, each input pulse creates multiple, temporally separated, ultrashort pulses of different wavelengths at the amplifier output. The number of pulses depends not only on the total gain of the amplifier but also on the width of input pulses.

  1. Enhanced Gain in Photonic Crystal Amplifiers

    DEFF Research Database (Denmark)

    Ek, Sara; Semenova, Elizaveta; Hansen, Per Lunnemann;

    2012-01-01

    study of a 1 QW photonic crystal amplifier. Net gain is achieved which enables laser oscillation in photonic crystal micro cavities. The ability to freely tailor the dispersion in a semiconductor optical amplifier makes it possible to raise the optical gain considerably over a certain bandwidth......We experimentally demonstrate enhanced gain in the slow-light regime of quantum well photonic crystal amplifiers. A strong gain enhancement is observed with the increase of the group refractive index, due to light slow-down. The slow light enhancement is shown in a amplified spontaneous emission...

  2. Reflection amplifiers in self-regulated learning

    NARCIS (Netherlands)

    Verpoorten, Dominique

    2012-01-01

    Verpoorten, D. (2012). Reflection amplifiers in self-regulated learning. Doctoral thesis. November, 9, 2012, Heerlen, The Netherlands: Open Universiteit (CELSTEC). Datawyse / Universitaire Pers Maastricht.

  3. Design of an 1800nm Raman amplifier

    DEFF Research Database (Denmark)

    Svane, Ask Sebastian; Rottwitt, Karsten

    2013-01-01

    We present the experimental results for a Raman amplifier that operates at 1810 nm and is pumped by a Raman fiber laser at 1680 nm. Both the pump laser and the Raman amplifier is polarization maintaining. A challenge when scaling Raman amplifiers to longer wavelengths is the increase...... in transmission loss, but also the reduction in the Raman gain coefficient as the amplifier wavelength is increased. Both polarization components of the Raman gain is characterized, initially for linearly co-polarized signal and pump, subsequently linearly polarized orthogonal signal and pump. The noise...

  4. The cascaded amplifier and saturable absorber (CASA) all-optical switch

    DEFF Research Database (Denmark)

    Hilliger, E.; Berger, J.; Weber, H. G.

    2001-01-01

    The cascaded amplifier and saturable absorber is presented as a new all-optical switching scheme for optical signal processing applications. First demultiplexing experiments demonstrate the principle of operation of this scheme....

  5. The cascaded amplifier and saturable absorber (CASA) all-optical switch

    DEFF Research Database (Denmark)

    Hilliger, E.; Berger, J.; Weber, H. G.

    2001-01-01

    The cascaded amplifier and saturable absorber is presented as a new all-optical switching scheme for optical signal processing applications. First demultiplexing experiments demonstrate the principle of operation of this scheme....

  6. Ping-pong auto-zero amplifier with glitch reduction

    Science.gov (United States)

    Larson, Mark R [Maple Grove, MN

    2008-01-22

    A ping-pong amplifier with reduced glitching is described. The ping-pong amplifier includes a nulling amplifier coupled to a switching network. The switching network is used to auto-zero a ping amplifier within a ping-pong amplifier. The nulling amplifier drives the output of a ping amplifier to a proper output voltage level during auto-zeroing of the ping amplifier. By being at a proper output voltage level, glitches associated with transitioning between a ping amplifier and a pong amplifier are reduced or eliminated.

  7. Distributed feedback laser amplifiers combining the functions of amplifiers and channel filters

    DEFF Research Database (Denmark)

    Wang, Z.; Durhuus, T.; Mikkelsen, Benny;

    1994-01-01

    A dynamic model for distributed feedback amplifiers, including the mode coupled equations and the carrier rate equation, is established. The presented mode coupled equations have taken into account the interaction between fast changing optical signal and the waveguide with corrugations. By showin...... the possibility of amplifying 100 ps pulses without pulse broadening, we anticipate that a distributed feedback amplifier can be used as a combined amplifier and channel filter in high bit rate transmission systems....

  8. Amplified spontaneous emission and its restraint in a terawatt Ti:sapphire amplifier

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Amplified spontaneous emission (ASE) and its restraint in a femtosecond Ti: sapphire chirped_pulse amplifier were investigated. The noises arising from ASE were effectively filtered out in the spatial, temporal and spectral domain. Pulses as short as 38 fs were amplified to peak power of 1.4 TW. The power ratio between the amplified femtosecond pulse and the ASE was higher than 106:1.

  9. Atomic Dipole Traps with Amplified Spontaneous Emission: A Proposal

    CERN Document Server

    Clément, Jean-François; Garreau, Jean Claude; Szriftgiser, Pascal

    2010-01-01

    We propose what we believe to be a novel type of optical source for ultra-cold atomic Far Off-Resonance optical-dipole Traps (FORTs). The source is based on an Erbium Amplified Spontaneous Emission (ASE) source that seeds a high power Erbium Doped Fiber Amplifier (EDFA). The main interest of this source is its very low coherence length, thus allowing an incoherent superposition of several trapping beams without any optical interference. The behavior of the superimposed beams is then a scalar sum greatly simplifying complex configurations. As an illustration, we report an estimation of the intensity noise of this source and an estimation of the atomic excess heating rate for an evaporative cooling experiment application. They are both found to be suitable for cold atoms experiments.

  10. High Average Power Optical FEL Amplifiers

    CERN Document Server

    Ben-Zvi, I; Litvinenko, V

    2005-01-01

    Historically, the first demonstration of the FEL was in an amplifier configuration at Stanford University. There were other notable instances of amplifying a seed laser, such as the LLNL amplifier and the BNL ATF High-Gain Harmonic Generation FEL. 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 a 100 kW average power FEL. The high electron beam power, high brightness and high efficiency that can be achieved with photoinjectors and superconducting energy recovery linacs combine well with the high-gain FEL amplifier to produce unprecedented average power FELs with some advantages. 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 Li...

  11. Self-pulsation in Raman fiber amplifiers

    DEFF Research Database (Denmark)

    Pedersen, Martin Erland Vestergaard; Ott, Johan Raunkjær; Rottwitt, Karsten

    2009-01-01

    Dynamic behavior caused by Brillouin scattering in Raman fiber amplifiers is studied. Modes of self-pulsation steady state oscillations are found. Their dependence on amplification scheme is demonstrated.......Dynamic behavior caused by Brillouin scattering in Raman fiber amplifiers is studied. Modes of self-pulsation steady state oscillations are found. Their dependence on amplification scheme is demonstrated....

  12. BROADBAND TRAVELLING WAVE SEMICONDUCTOR OPTICAL AMPLIFIER

    DEFF Research Database (Denmark)

    2010-01-01

    Broadband travelling wave semiconductor optical amplifier (100, 200, 300, 400, 800) for amplification of light, wherein the amplifier (100, 200, 300, 400, 800) comprises a waveguide region (101, 201, 301, 401, 801) for providing confinement of the light in transverse directions and adapted...

  13. Optimizing learning of a locomotor task: amplifying errors as needed.

    Science.gov (United States)

    Marchal-Crespo, Laura; López-Olóriz, Jorge; Jaeger, Lukas; Riener, Robert

    2014-01-01

    Research on motor learning has emphasized that errors drive motor adaptation. Thereby, several researchers have proposed robotic training strategies that amplify movement errors rather than decrease them. In this study, the effect of different robotic training strategies that amplify errors on learning a complex locomotor task was investigated. The experiment was conducted with a one degree-of freedom robotic stepper (MARCOS). Subjects were requested to actively coordinate their legs in a desired gait-like pattern in order to track a Lissajous figure presented on a visual display. Learning with three different training strategies was evaluated: (i) No perturbation: the robot follows the subjects' movement without applying any perturbation, (ii) Error amplification: existing errors were amplified with repulsive forces proportional to errors, (iii) Noise disturbance: errors were evoked with a randomly-varying force disturbance. Results showed that training without perturbations was especially suitable for a subset of initially less-skilled subjects, while error amplification seemed to benefit more skilled subjects. Training with error amplification, however, limited transfer of learning. Random disturbing forces benefited learning and promoted transfer in all subjects, probably because it increased attention. These results suggest that learning a locomotor task can be optimized when errors are randomly evoked or amplified based on subjects' initial skill level.

  14. Ultrafast disk lasers and amplifiers

    Science.gov (United States)

    Sutter, Dirk H.; Kleinbauer, Jochen; Bauer, Dominik; Wolf, Martin; Tan, Chuong; Gebs, Raphael; Budnicki, Aleksander; Wagenblast, Philipp; Weiler, Sascha

    2012-03-01

    Disk lasers with multi-kW continuous wave (CW) output power are widely used in manufacturing, primarily for cutting and welding applications, notably in the automotive industry. The ytterbium disk technology combines high power (average and/or peak power), excellent beam quality, high efficiency, and high reliability with low investment and operating costs. Fundamental mode picosecond disk lasers are well established in micro machining at high throughput and perfect precision. Following the world's first market introduction of industrial grade 50 W picosecond lasers (TruMicro 5050) at the Photonics West 2008, the second generation of the TruMicro series 5000 now provides twice the average power (100 W at 1030 nm, or 60 W frequency doubled, green output) at a significantly reduced footprint. Mode-locked disk oscillators achieve by far the highest average power of any unamplified lasers, significantly exceeding the 100 W level in laboratory set-ups. With robust long resonators their multi-microjoule pulse energies begin to compete with typical ultrafast amplifiers. In addition, significant interest in disk technology has recently come from the extreme light laser community, aiming for ultra-high peak powers of petawatts and beyond.

  15. Design and performance of the beamlet amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Erlandson, A.C.; Rotter, M.D.; Frank, M.D.; McCracken, R.W.

    1996-06-01

    In future laser systems, such as the National Ignition Facility (NIF), multi-segment amplifiers (MSAs) will be used to amplify the laser beam to the required levels. As a prototype of such a laser architecture, the authors have designed, built, and tested flash-lamp-pumped, Nd:Glass, Brewster-angle slab MSAs for the Beamlet project. In this article, they review the fundamentals of Nd:Glass amplifiers, describe the MSA geometry, discuss parameters that are important in amplifier design, and present our results on the characterization of the Beamlet MSAs. In particular, gain and beam steering measurements show that the Beamlet amplifiers meet all optical performance specifications and perform close to model predictions.

  16. Amplified OTDR systems for multipoint corrosion monitoring.

    Science.gov (United States)

    Nascimento, Jehan F; Silva, Marcionilo J; Coêlho, Isnaldo J S; Cipriano, Eliel; Martins-Filho, Joaquim F

    2012-01-01

    We present two configurations of an amplified fiber-optic-based corrosion sensor using the optical time domain reflectometry (OTDR) technique as the interrogation method. The sensor system is multipoint, self-referenced, has no moving parts and can measure the corrosion rate several kilometers away from the OTDR equipment. The first OTDR monitoring system employs a remotely pumped in-line EDFA and it is used to evaluate the increase in system reach compared to a non-amplified configuration. The other amplified monitoring system uses an EDFA in booster configuration and we perform corrosion measurements and evaluations of system sensitivity to amplifier gain variations. Our experimental results obtained under controlled laboratory conditions show the advantages of the amplified system in terms of longer system reach with better spatial resolution, and also that the corrosion measurements obtained from our system are not sensitive to 3 dB gain variations.

  17. Amplified OTDR Systems for Multipoint Corrosion Monitoring

    Directory of Open Access Journals (Sweden)

    Joaquim F. Martins-Filho

    2012-03-01

    Full Text Available We present two configurations of an amplified fiber-optic-based corrosion sensor using the optical time domain reflectometry (OTDR technique as the interrogation method. The sensor system is multipoint, self-referenced, has no moving parts and can measure the corrosion rate several kilometers away from the OTDR equipment. The first OTDR monitoring system employs a remotely pumped in-line EDFA and it is used to evaluate the increase in system reach compared to a non-amplified configuration. The other amplified monitoring system uses an EDFA in booster configuration and we perform corrosion measurements and evaluations of system sensitivity to amplifier gain variations. Our experimental results obtained under controlled laboratory conditions show the advantages of the amplified system in terms of longer system reach with better spatial resolution, and also that the corrosion measurements obtained from our system are not sensitive to 3 dB gain variations.

  18. Detection of Non-Amplified Genomic DNA

    CERN Document Server

    Corradini, Roberto

    2012-01-01

    This book offers a state-of-the-art overview on non amplified DNA detection methods and provides chemists, biochemists, biotechnologists and material scientists with an introduction to these methods. In fact all these fields have dedicated resources to the problem of nucleic acid detection, each contributing with their own specific methods and concepts. This book will explain the basic principles of the different non amplified DNA detection methods available, highlighting their respective advantages and limitations. The importance of non-amplified DNA sequencing technologies will be also discussed. Non-amplified DNA detection can be achieved by adopting different techniques. Such techniques have allowed the commercialization of innovative platforms for DNA detection that are expected to break into the DNA diagnostics market. The enhanced sensitivity required for the detection of non amplified genomic DNA has prompted new strategies that can achieve ultrasensitivity by combining specific materials with specifi...

  19. Design of an 1800 nm Raman Amplifier

    DEFF Research Database (Denmark)

    Svane, Ask Sebastian; Rottwitt, Karsten

    , also extended band amplifiers are required. As a solution to the latter challenge, Raman amplifiers are suggested as promising candidates. The main hurdle when designing a long wavelength Raman amplifier is the increased intrinsic fiber attenuation which as a consequence leads to an increase...... in the pump power requirement and deteriorated noise properties. Here we demonstrate a Raman amplifier designed for signal wavelengths around 1800 nm. The amplification fiber is an OFS PM Raman fiber, and is pumped by a Raman fiber laser emitting at 1680 nm [4]. The amplifier was pumped co......-polarized and backward, with respect to the singal. In Fig. 2 a measured Raman on/off gain exceeding 9 dB for 285 mW of injected pump power is obtained in a 4.35 km long fiber. A broadband supercontinuum source was used as a signal from 1700 nm to 1900 nm....

  20. An Implantable CMOS Amplifier for Nerve Signals

    DEFF Research Database (Denmark)

    Nielsen, Jannik Hammel; Lehmann, Torsten

    2001-01-01

    In this paper, a low noise high gain CMOS amplifier for minute nerve signals is presented. By using a mixture of weak- and strong inversion transistors, optimal noise suppression in the amplifier is achieved. A continuous-time offset-compensation technique is utilized in order to minimize impact...... on the amplifier input nodes. The method for signal recovery from noisy nerve signals is presented. A prototype amplifier is realized in a standard digital 0.5 μm CMOS single poly, n-well process. The prototype amplifier features a gain of 80 dB over a 3.6 kHz bandwidth, a CMRR of more than 87 dB and a PSRR...

  1. Four-Wave Mixing Aplication in Semiconductor Optical Amplifier

    Directory of Open Access Journals (Sweden)

    Radoslav Odrobinak

    2004-01-01

    Full Text Available Four-Wave Mixing (FWM in semiconductor optical amplifiers is an attrative mechanism for wavelenght coversion in wavelenght-division multiplexed (WDM systems since it provides modulation format and bit rate transparency over wide tuning ranges. A series of systems experiments evaluating several aspects of the performance of these devices at bit rates of 2.5 and 10 Gb/s are presented.

  2. Measuring Optimal Length of the Amplifying Fiber in Different Working Conditions of the Amplifier

    Directory of Open Access Journals (Sweden)

    Radek Poboril

    2014-01-01

    Full Text Available The aim of this article is to highlight possible unwanted behaviour of an EDFA optical amplifier during temperature changes. After a brief introduction dealing with amplifiers and doped fibers in general we focus on the assembly of our own EDFA amplifier with standard construction and the IsoGain I-6 amplifying fiber, and on the parameters of its individual components. Since an erbium doped fiber has usually no direct thermal stabilization, temperature changes can affect performance of the entire amplifier. The next part of the article therefore describes the impacts of such changes on behaviour of our amplifier. At the very end we performed a measurement of the amplifier deployed in the actual WDM-PON the description of which can be found in the last chapter.

  3. Ultra-low noise miniaturized neural amplifier with hardware averaging

    Science.gov (United States)

    Dweiri, Yazan M.; Eggers, Thomas; McCallum, Grant; Durand, Dominique M.

    2015-08-01

    Objective. Peripheral nerves carry neural signals that could be used to control hybrid bionic systems. Cuff electrodes provide a robust and stable interface but the recorded signal amplitude is small (amplifier should add as little noise as possible. Since mainstream neural amplifiers have a baseline noise of 2 μVrms or higher, novel designs are required. Approach. Here we apply the concept of hardware averaging to nerve recordings obtained with cuff electrodes. An optimization procedure is developed to minimize noise and power simultaneously. The novel design was based on existing neural amplifiers (Intan Technologies, LLC) and is validated with signals obtained from the FINE in chronic dog experiments. Main results. We showed that hardware averaging leads to a reduction in the total recording noise by a factor of 1/√N or less depending on the source resistance. Chronic recording of physiological activity with FINE using the presented design showed significant improvement on the recorded baseline noise with at least two parallel operation transconductance amplifiers leading to a 46.1% reduction at N = 8. The functionality of these recordings was quantified by the SNR improvement and shown to be significant for N = 3 or more. The present design was shown to be capable of generating amplifier. Significance. These results demonstrate the efficacy of hardware averaging on noise improvement for neural recording with cuff electrodes, and can accommodate the presence of high source impedances that are associated with the miniaturized contacts and the high channel count in electrode arrays. This technique can be adopted for other applications where miniaturized and implantable multichannel acquisition systems with ultra-low noise and low power are required.

  4. In situ monitoring of the electrochemical absorption of deuterium into palladium by x-ray diffraction using synchrotron-wiggler radiation

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez, D.D.; Hagans, P.L.; Skelton, E.F.; Qadri, S.B.; Nagel, D.J. [Naval Research Lab., Washington, DC (United States)

    1998-12-31

    With low energy x-rays, such as those from a Cu x-ray tube, only the outer few microns of a metallic sample can be probed. This low penetrating power prohibits structural studies from being carried out on the interior of an electrode in an electrochemical cell because of absorption by the cell material, electrodes and the electrolyte. The work described in this paper circumvents this problem by utilizing high energy, high brightness x-rays produced on the superconducting wiggler beam line, X-17C, at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory. The penetrating power of the higher energy x-rays allowed Pd diffraction spectra to be obtained in-situ on a 1 mm diameter Pd wire cathode during electrolysis of heavy water. Moreover, the beam (28 x 28 {micro}m in cross-section) allowed diffraction spectra to be acquired as a function of distance across the sample. Spectra were recorded in 50 {micro}m steps from the edge of the Pd wire to its core. This was done at 2 minute intervals as a function of electrolysis time. The {alpha}-{beta} phase transition induced in the Pd while deuterium was electrochemically absorbed was observed by monitoring the Pd-(422) diffraction peaks. Results allowed the diffusion rate and the diffusivity of deuterium atoms in the Pd wire to be determined. Other features of the structural changes associated with the absorption of deuterium into Pd are reported.

  5. Effect of Soliton Propagation in Fiber Amplifiers

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The propagation of optical solitons in fiber amplifiers is discussed by considering a model that includes linear high order dispersion, two-photon absorption, nonlinear high-order dispersion, self-induced Ramam and five-order nonlinear effects. Based on travelling wave method, the solutions of the nonlinear Schrdinger equations, and the influence on soliton propagation as well as high-order effect in the fiber amplifier are discussed in detail. It is found that because of existing five-order nonlinear effect, the solution is not of secant hyperbola type, but shows high gain state of the fiber amplifier which is very favourable to the propagation of solitons.

  6. Experimental design of laminar proportional amplifiers

    Science.gov (United States)

    Hellbaum, R. F.

    1976-01-01

    An experimental program was initiated at Langley Research Center to study the effects of various parameters on the design of laminar proportional beam deflection amplifiers. Matching and staging of amplifiers to obtain high-pressure gain was also studied. Variable parameters were aspect ratio, setback, control length, receiver distance, receiver width, width of center vent, and bias pressure levels. Usable pressure gains from 4 to 19 per stage can now be achieved, and five amplifiers were staged together to yield pressure gains up to 2,000,000.

  7. Quantum electronics maser amplifiers and oscillators

    CERN Document Server

    Fain, V M; Sanders, J H

    2013-01-01

    Quantum Electronics, Volume 2: Maser Amplifiers and Oscillators deals with the experimental and theoretical aspects of maser amplifiers and oscillators which are based on the principles of quantum electronics. It shows how the concepts and equations used in quantum electronics follow from the basic principles of theoretical physics.Comprised of three chapters, this volume begins with a discussion on the elements of the theory of quantum oscillators and amplifiers working in the microwave region, along with the practical achievements in this field. Attention is paid to two-level paramagnetic ma

  8. High Efficiency Microwave Power Amplifier (HEMPA) Design

    Science.gov (United States)

    Sims, W. Herbert

    2004-01-01

    This paper will focus on developing an exotic switching technique that enhances the DC-to-RF conversion efficiency of microwave power amplifiers. For years, switching techniques implemented in the 10 kHz to 30 MHz region have resulted in DC-to-RF conversion efficiencies of 90-95-percent. Currently amplifier conversion efficiency, in the 2-3 GHz region approaches, 10-20-percent. Using a combination of analytical modeling and hardware testing, a High Efficiency Microwave Power Amplifier was built that demonstrated conversion efficiencies four to five times higher than current state of the art.

  9. Fundamentals of RF and microwave transistor amplifiers

    CERN Document Server

    Bahl, Inder J

    2009-01-01

    A Comprehensive and Up-to-Date Treatment of RF and Microwave Transistor Amplifiers This book provides state-of-the-art coverage of RF and microwave transistor amplifiers, including low-noise, narrowband, broadband, linear, high-power, high-efficiency, and high-voltage. Topics covered include modeling, analysis, design, packaging, and thermal and fabrication considerations. Through a unique integration of theory and practice, readers will learn to solve amplifier-related design problems ranging from matching networks to biasing and stability. More than 240 problems are included to help read

  10. An Envelope Hammerstein Model for Power Amplifiers

    Institute of Scientific and Technical Information of China (English)

    Hua-Dong Wang; Song-Bai He; Jing-Fu Bao; Zheng-De Wu

    2007-01-01

    In this paper, an envelope Hammerstein(EH) model is introduced to describe dynamic inputoutput characteristics of RF power amplifiers. In the modeling approach, we use a new truncation method and an established nonlinear time series method to determine model structure. Then, we discuss the process of model parameter extraction in detailed. Finally, a 2 W WCDMA power amplifier is measured to verify the performance of EH model, and good agreement between model output and measurement result shows our model can accurately predict output characteristic of the power amplifier.

  11. Achieving and maintaining cleanliness in NIF amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Burnham, A. K.; Horvath, J. A.; Letts, S. A.; Menapace, J. A.; Stowers, I. F.

    1998-07-28

    Cleanliness measurements made on AMPLAB prototype National Ignition Facility (NIF) laser amplifiers during assembly, cassette transfer, and amplifier operation are summarized. These measurements include particle counts from surface cleanliness assessments using filter swipe techniques and from airborne particle monitoring. Results are compared with similar measurements made on the Beamlet and Nova lasers and in flashlamp test fixtures. Observations of Class 100,000 aerosols after flashlamp firings are discussed. Comparisons are made between typical damage densities on laser amplifier optics from Novette, NOVA, Beamlet, and AMPLAB.

  12. Holey fiber amplifiers and lasers

    OpenAIRE

    Richardson, D J; Furusawa, K.; Kogure, T.; Price, J.H.V.; Lee, J.H.; Monro, T.M.

    2004-01-01

    We review our recent activities in the development of small-core, active holey fibers and describe a number of experiments that highlight the advantages of this technology within a range of both linear and nonlinear devices.

  13. High-energy nanosecond radially polarized beam output from Nd:YAG amplifiers

    Science.gov (United States)

    Chang, Chengcheng; Chen, Xudong; Pu, Jixiong

    2017-04-01

    Radially polarized laser beam amplification up to the 772 mJ using flash-lamp-pumped Nd:YAG amplifiers was demonstrated. In the experiments, a nanosecond radially polarized seed beam was converted from a conventional Q-switched Nd:YAG laser output with a polarization converter and then amplified with two Nd:YAG amplifier stages. A maximum amplification output energy up to 772 mJ was achieved at 10 Hz with a 10-ns pulse, corresponding to an amplification factor of 323%. Excellent conservation of polarization was also obtained during the amplification.

  14. SEMICONDUCTOR DEVICES Effect of collector bias current on the linearity of common-emitter BJT amplifiers

    Science.gov (United States)

    Kun, Li; Jianfu, Teng; Xiuwei, Xuan

    2010-12-01

    Using a Volterra series, an explicit formula is derived for the connection between input 3rd-order intercept point and collector bias current (ICQ) in a common-emitter bipolar junction transistor amplifier. The analysis indicates that the larger ICQ is, the more linear the amplifier is. Furthermore, this has been verified by experiment. This study also integrates a method called dynamic bias current for expanding the dynamic range of an LNA (low noise amplifier) as an application of the analysis result obtained above. IMR3 (3rd-order intermodulation rate) is applied to evaluate the LNA's performance with and without adopting this method in this study.

  15. Graphene-based side-polished optical fiber amplifier.

    Science.gov (United States)

    Karimi, Mohammad; Ahmadi, Vahid; Ghezelsefloo, Masoud

    2016-12-20

    We demonstrate a novel design for optical fiber amplifiers, utilizing side-polished fibers with a single-layer graphene overlay as the active medium and carrier injection in the graphene layer to provide the required inversion. We study the effects of an electrically induced graphene p-i-n heterojunction in the forward bias regime on optical modes of side-polished fibers and show that gain values of 0.51, 1.81, and 1.79 dB/cm for wavelengths 1064, 1330, and 1550 nm can be obtained for single-mode side-polished fibers. Our results show that in multi-mode side-polished fibers, higher order modes experience higher values of gain, and gain can be increased by increasing polished depth. The proposed system is a tunable wideband optical amplifier that can operate for wavelengths larger than 1000 nm.

  16. Low-voltage CMOS operational amplifiers theory, design and implementation

    CERN Document Server

    Sakurai, Satoshi

    1995-01-01

    Low-Voltage CMOS Operational Amplifiers: Theory, Design and Implementation discusses both single and two-stage architectures. Opamps with constant-gm input stage are designed and their excellent performance over the rail-to-rail input common mode range is demonstrated. The first set of CMOS constant-gm input stages was introduced by a group from Technische Universiteit, Delft and Universiteit Twente, the Netherlands. These earlier versions of circuits are discussed, along with new circuits developed at the Ohio State University. The design, fabrication (MOSIS Tiny Chips), and characterization of the new circuits are now complete. Basic analog integrated circuit design concepts should be understood in order to fully appreciate the work presented. However, the topics are presented in a logical order and the circuits are explained in great detail, so that Low-Voltage CMOS Operational Amplifiers can be read and enjoyed by those without much experience in analog circuit design. It is an invaluable reference boo...

  17. Physics of vertically integrated waveguide photodetectors and amplifiers. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Wright, E.M. [Univ. of Arizona, Tucson, AZ (United States). Optical Sciences Center

    1993-11-01

    This report describes the efforts supported by LLNL under the Subcontract No. B239593 at the University of Arizona during the Fiscal Year 1992. A solid physical foundation has been developed for understanding the operation of vertically integrated photodetectors and amplifiers. This has been achieved through a combination of numerical simulation and development of simple coupled-mode theories. Coupled-mode theory has been used to elucidate the physics underlying the operation of vertically integrated photodetectors. In particular, the relation between the spatial transients observed in experiments and numerical simulations, and the non-power orthogonality of the underlying modes has been clarified. The coupled-mode theory has been extended to the case of coupled waveguide-amplifiers.

  18. Self-pulsation in Raman fiber amplifiers

    OpenAIRE

    Pedersen, Martin Erland Vestergaard; Ott, Johan Raunkjær; Rottwitt, Karsten

    2009-01-01

    Dynamic behavior caused by Brillouin scattering in Raman fiber amplifiers is studied. Modes of self-pulsation steady state oscillations are found. Their dependence on amplification scheme is demonstrated.

  19. Laser Cooled High-Power Fiber Amplifier

    CERN Document Server

    Nemova, Galina

    2009-01-01

    A theoretical model for laser cooled continuous-wave fiber amplifier is presented. The amplification process takes place in the Tm3+-doped core of the fluoride ZBLAN (ZrF4-BaF2-LaF3-AlF3-NaF) glass fiber. The cooling process takes place in the Yb3+:ZBLAN fiber cladding. It is shown that for each value of the pump power and the amplified signal there is a distribution of the concentration of the Tm3+ along the length of the fiber amplifier, which provides its athermal operation. The influence of a small deviation in the value of the amplified signal on the temperature of the fiber with the fixed distribution of the Tm3+ions in the fiber cladding is investigated.

  20. High Energy Single Frequency Resonant Amplifier Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR phase I project proposes a single frequency high energy resonant amplifier for remote sensing. Current state-of-art technologies can not provide all...

  1. CMOS current amplifiers : speed versus nonlinearity

    OpenAIRE

    2000-01-01

    This work deals with analogue integrated circuit design using various types of current-mode amplifiers. These circuits are analysed and realised using modern CMOS integration technologies. The dynamic nonlinearities of these circuits are discussed in detail as in the literature only linear nonidealities and static nonlinearities are conventionally considered. For the most important open-loop current-mode amplifier, the second-generation current-conveyor (CCII), a macromodel is derived tha...

  2. Quantum cloning with an optical fiber amplifier

    CERN Document Server

    Fasel, S; Ribordy, G; Scarani, V; Zbinden, H; Fasel, Sylvain; Gisin, Nicolas; Ribordy, Gregoire; Scarani, Valerio; Zbinden, Hugo

    2002-01-01

    It has been shown theoretically that a light amplifier working on the physical principle of stimulated emission should achieve optimal quantum cloning of the polarization state of light. We demonstrate close-to-optimal universal quantum cloning of polarization in a standard fiber amplifier for telecom wavelengths. For cloning $1\\to 2$ we find a fidelity of 0.82, the optimal value being ${5/6}=0.83$.

  3. Efficient Power Amplifier for Motor Control

    Science.gov (United States)

    Brown, R. J.

    1986-01-01

    Pulse-width-modulated amplifier supplies high current as efficiently as low current needed for starting and running motor. Key to efficiency of motor-control amplifier is V-channel metal-oxide/semiconductor transistor Q1. Device has low saturation resistance. However, has large gate input capacitance and small margin between its turn-on voltage and maximum allowable gate-to-source voltage. Circuits for output stages overcome limitations of VMOS device.

  4. MMIC Amplifiers for 90 to 130 GHz

    Science.gov (United States)

    Samoska, Lorene; Pukala, David; Peralta, Alejandro; Bryerton, Eric; Morgan, Matt; Boyd, T.; Hu, Ming; Schmitz, Adele

    2007-01-01

    This brief describes two monolithic microwave integrated-circuit (MMIC) amplifier chips optimized to function in the frequency range of 90 to 130 GHz, covering nearly all of F-band (90 - 140 GHz). These amplifiers were designed specifically for local-oscillator units in astronomical radio telescopes such as the Atacama Large Millimeter Array (ALMA). They could also be readily adapted for use in electronic test equipment, automotive radar systems, and communications systems that operate between 90 and 130 GHz.

  5. Some Notes on Wideband Feedback Amplifiers

    Science.gov (United States)

    Fitch, V.

    1949-03-16

    The extension of the passband of wideband amplifiers is a highly important problem to the designer of electronic circuits. Throughout the electronics industry and in many research programs in physics and allied fields where extensive use is made of video amplifiers, the foremost requirement is a passband of maximum width. This is necessary if it is desired to achieve a more faithful reproduction of transient wave forms, a better time resolution in physical measurements, or perhaps just a wider band gain-frequency response to sine wave signals. The art of electronics is continually faced with this omnipresent amplifier problem. In particular, the instrumentation techniques of nuclear physics require amplifiers with short rise times, a high degree of gain stability, and a linear response to high signal levels. While the distributed amplifier may solve the problems of those seeking only a wide passband, the requirements of stability and linearity necessitate using feedback circuits. This paper considers feedback amplifiers from the standpoint of high-frequency performance. The circuit conditions for optimum steady-state (sinusoidal) and transient response are derived and practical circuits (both interstage and output) are presented which fulfill these conditions. In general, the results obtained may be applied to the low-frequency end.

  6. In-Phase Wavelength Conversion Based On Cross-Gain Modulation in Semiconductor Optical Amplifier

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xinliang; HUANG Dexiu; SUN Junqiang; LIU Deming; YI Heqing

    2000-01-01

    In-phase wavelength conversion based on cross-gain modulation in a semiconductor optical amplifier biased around critical threshold current has been demonstrated. The converted signal and the pump signal have the same bit sequence 1101011000. The stimulated emission competition between the amplification of input signals and the amplified spontaneous emission was used to illustrate the conversion mechanism. Experiment results showed that in-phase wavelength conversion can be achieved with simple structure and high output extinction ratio.

  7. Amplify Errors to Minimize Them

    Science.gov (United States)

    Stewart, Maria Shine

    2009-01-01

    In this article, the author offers her experience of modeling mistakes and writing spontaneously in the computer classroom to get students' attention and elicit their editorial response. She describes how she taught her class about major sentence errors--comma splices, run-ons, and fragments--through her Sentence Meditation exercise, a rendition…

  8. Low Noise Optically Pre-amplified Lightwave Receivers and Other Applications of Fiber Optic Parametric Amplifiers

    Science.gov (United States)

    2010-07-27

    noise performance, optical gain bandwidth, and power efficiency. An interesting alternative to the mature Erbium-doped fiber amplifier ( EDFA ) is the...fibers (HNLF) and high power booster EDFAs . The FOPA can provide a very wide gain bandwidth [2], very high gain (70 dB was demonstrated in [3]), and...amplified spontaneous emission (ASE) noise in EDFAs is also generated. It is sometimes referred to as amplified quantum noise. Maximum gain (at the gain

  9. Neuropathology of ablation of rat gliosarcomas and contiguous brain tissues using a microplanar beam of synchrotron-wiggler-generated X rays.

    Science.gov (United States)

    Laissue, J A; Geiser, G; Spanne, P O; Dilmanian, F A; Gebbers, J O; Geiser, M; Wu, X Y; Makar, M S; Micca, P L; Nawrocky, M M; Joel, D D; Slatkin, D N

    1998-11-23

    Adult-rat-brain tissues display an unusually high resistance to necrosis when serially irradiated with parallel, thin slices of a microplanar (i.e., microscopically thin and macroscopically broad) beam of synchrotron-wiggler-generated, approx. 35-120 keV (median approx. 50 keV) Gd-filtered X rays at skin-entrance absorbed doses of 312 to 5000 Gy per slice. Such microplanar beams were used to irradiate young adult rats bearing right frontocerebral 9L gliosarcomas (approx. 4 mm diameter), through a volume of tissue containing the tumor and contiguous brain tissue, either in a single array or in 2 orthogonally crossed arrays of tissue slices. Each array included 101 parallel microplanar slices, 100 microm center-to-center distance, each slice being approx. 25 microm wide and 12 mm high, with skin-entrance absorbed doses of 312.5 Gy or 625 Gy per slice. Compared with unirradiated controls with a median survival time of 20 days after tumor initiation, the median survival time was extended in irradiated rats by 139 days (625 Gy, crossed arrays), 96 days (312 Gy, crossed arrays) or 24 days (625 Gy, single array). The tumors disappeared in 22 of the 36 irradiated rats, 4/11 even after unidirectional microbeam irradiation. The extent and severity of radiation damage to the normal brain in rats with or without tumor was graded histopathologically. Correlation of those grades with radiation doses shows that loss of tissue structure was confined to beam-crossing regions and that only minor damage was done to zones of the brain irradiated unidirectionally.

  10. Fiber optical parametric amplifiers in optical communication systems.

    Science.gov (United States)

    Marhic, Michel E; Andrekson, Peter A; Petropoulos, Periklis; Radic, Stojan; Peucheret, Christophe; Jazayerifar, Mahmoud

    2015-01-01

    The prospects for using fiber optical parametric amplifiers (OPAs) in optical communication systems are reviewed. Phase-insensitive amplifiers (PIAs) and phase-sensitive amplifiers (PSAs) are considered. Low-penalty amplification at/or near 1 Tb/s has been achieved, for both wavelength- and time-division multiplexed formats. High-quality mid-span spectral inversion has been demonstrated at 0.64 Tb/s, avoiding electronic dispersion compensation. All-optical amplitude regeneration of amplitude-modulated signals has been performed, while PSAs have been used to demonstrate phase regeneration of phase-modulated signals. A PSA with 1.1-dB noise figure has been demonstrated, and preliminary wavelength-division multiplexing experiments have been performed with PSAs. 512 Gb/s have been transmitted over 6,000 km by periodic phase conjugation. Simulations indicate that PIAs could reach data rate x reach products in excess of 14,000 Tb/s × km in realistic wavelength-division multiplexed long-haul networks. Technical challenges remaining to be addressed in order for fiber OPAs to become useful for long-haul communication networks are discussed. [Formula: see text].

  11. High power, high beam quality regenerative amplifier

    Science.gov (United States)

    Hackel, L.A.; Dane, C.B.

    1993-08-24

    A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

  12. Operational amplifier with adjustable frequency response.

    Science.gov (United States)

    Gulisek, D; Hencek, M

    1978-01-01

    The authors describe an operational amplifier with an adjustable frequency response and its use in membrane physiology, using the voltage clamp and current clamp method. The amplifier eliminates feedback poles causing oscillation. It consists of a follower with a high input resistance in the form of a tube and of an actual amplifier with an adjustable frequency response allowing the abolition of clicks by one pole and of oscillation by two poles in the 500 Hz divided by infinity range. Further properties of the amplifier: a long-term voltage drift of 1 mv, a temperature voltage drift of 0.5 mv/degrees K, input resistance greater than 1 GOhm, amplification greater than 80 dB, output +/- 12 v, 25 ma, noise, measured from the width of the oscilloscope track in the presence of a ray of normal brightness, not exceeding 50 muv in the 0-250 kHz band, f1 = 1 MHz. A short report on the amplifier was published a few years ago (Gulísek and Hencek 1973).

  13. Transpermeance Amplifier Applied to Magnetic Bearings

    Directory of Open Access Journals (Sweden)

    Jossana Ferreira

    2017-02-01

    Full Text Available The most conventional approach of controlling magnetic forces in active magnetic bearings (AMBs is through current feedback amplifiers: transconductance. This enables the operation of the AMB to be understood in terms of a relatively simple current-based model as has been widely reported on in the literature. The alternative notion of using transpermeance amplifiers, which approximate the feedback of gap flux rather than current, has been in commercial use in some form for at least thirty years, however is only recently seeing more widespread acceptance as a commercial standard. This study explores how such alternative amplifiers should be modeled and then examines the differences in behavior between AMBs equipped with transconductance and transpermeance amplifiers. The focus of this study is on two aspects. The first is the influence of rotor displacement on AMB force, commonly modeled as a constant negative equivalent mechanical stiffness, and it is shown that either scheme actually leads to a finite bandwidth effect, but that this bandwidth is much lower when transpermeance is employed. The second aspect is the influence of eddy currents. Using a very simple model of eddy currents (a secondary short-circuited coil, it is demonstrated that transpermeance amplifiers can recover significant actuator bandwidth compared with transconductance, but at the cost of needing increased peak current headroom.

  14. The OPTHER Project: Progress toward the THz Amplifier

    DEFF Research Database (Denmark)

    Paoloni, C; Brunetti, F; Di Carlo, A

    2011-01-01

    This paper describes the status of the OPTHER (OPtically driven TeraHertz AmplifiERs) project and progress toward the THz amplifier realization. This project represents a considerable advancement in the field of high frequency amplification. The design and realization of a THz amplifier within th...

  15. 21 CFR 870.2060 - Transducer signal amplifier and conditioner.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Transducer signal amplifier and conditioner. 870... Transducer signal amplifier and conditioner. (a) Identification. A transducer signal amplifier and conditioner is a device used to provide the excitation energy for the transducer and to amplify or condition...

  16. An integrated, low noise patch-clamp amplifier for biological nanopore applications.

    Science.gov (United States)

    Wang, Gang; Dunbar, William B

    2010-01-01

    We present an integrated, low noise patch-clamp amplifier for biological nanopore applications. Our amplifier consists of an integrator-differentiator architecture coupled with a novel opamp design in the CMOS 0.35 µm process. The post-layout full-chip simulation shows the input referred noise of the amplifier is 0.49 pA RMS over a 5 kHz bandwidth using a verified electrical model for the biological nanopore system. In our biological nanopore experiments studying protein-DNA interactions, we encounter capacitive transients with a nominal settling time of 5 ms. Our amplifier design reduces the settling time to 0.2 ms, without requiring any compensation circuitry.

  17. X-band inverse class-F GaN internally-matched power amplifier

    Science.gov (United States)

    Zhao, Bo-Chao; Lu, Yang; Han, Wen-Zhe; Zheng, Jia-Xin; Zhang, Heng-Shuang; Ma, Pei-jun; Ma, Xiao-Hua; Hao, Yue

    2016-09-01

    An X-band inverse class-F power amplifier is realized by a 1-mm AlGaN/GaN high electron mobility transistor (HEMT). The intrinsic and parasitic components inside the transistor, especially output capacitor Cds, influence the harmonic impedance heavily at the X-band, so compensation design is used for meeting the harmonic condition of inverse class-F on the current source plane. Experiment results show that, in the continuous-wave mode, the power amplifier achieves 61.7% power added efficiency (PAE), which is 16.3% higher than the class-AB power amplifier realized by the same kind of HEMT. To the best of our knowledge, this is the first inverse class-F GaN internally-matched power amplifier, and the PAE is quite high at the X-band. Project supported by the National High Technology Research and Development Program of China (Grant No. 2015AA016801).

  18. Nonlinear phase noise mitigation in phase-sensitive amplified transmission systems.

    Science.gov (United States)

    Olsson, Samuel L I; Karlsson, Magnus; Andrekson, Peter A

    2015-05-04

    We investigate the impact of in-line amplifier noise in transmission systems amplified by two-mode phase-sensitive amplifiers (PSAs) and present the first experimental demonstration of nonlinear phase noise (NLPN) mitigation in a modulation format independent PSA-amplified transmission system. The NLPN mitigation capability is attributed to the correlated noise on the signal and idler waves at the input of the transmission span. We study a single-span system with noise loading in the transmitter but the results are expected to be applicable also in multi-span systems. The experimental investigation is supported by numerical simulations showing excellent agreement with the experiments. In addition to demonstrating NLPN mitigation we also present a record high sensitivity receiver, enabled by low-noise PSA-amplification, requiring only 4.1 photons per bit to obtain a bit error ratio (BER) of 1 × 10(-3) with 10 GBd quadrature phase-shift keying (QPSK) data.

  19. Ultrafast Gain Dynamics in Quantum Dot Amplifiers: Theoretical Analysis and Experimental Investigations

    DEFF Research Database (Denmark)

    Poel, Mike van der; Gehrig, Edeltraud; Hess, Ortwin;

    2005-01-01

    Ultrafast gain dynamics in an optical amplifier with an active layer of self-organized quantum dots (QDs) emitting near 1.3$muhbox m$is characterized experimentally in a pump-probe experiment and modeled theoretically on the basis of QD Maxwell–Bloch equations. Experiment and theory are in good...

  20. The Electron Beam Semiconductor (EBS) amplifier

    Science.gov (United States)

    True, R. M.; Baxendale, J. F.

    1980-07-01

    The Electron Beam Semiconductor (EBS) concept has existed for three decades; but only within the last decade has an active, well-defined program been underway to develop devices that can operate as high-power radio frequency(RF) amplifiers, fast risetime switches, and current and voltage pulse amplifiers. This report discusses the test procedures, data and results of reliability testing of RF and video pulse EBS amplifiers at Electronics Research and Development Command (ERADCOM), Fort Monmouth, New Jersey. Also, the experimental analysis of the series connected diode EBS device is described in detail. Finally, the report concludes with a discussion of the state-of-the-art of EBS and future trends of the technology.

  1. Implementation of a nondeterministic optical noiseless amplifier.

    Science.gov (United States)

    Ferreyrol, Franck; Barbieri, Marco; Blandino, Rémi; Fossier, Simon; Tualle-Brouri, Rosa; Grangier, Philippe

    2010-03-26

    Quantum mechanics imposes that any amplifier that works independently on the phase of the input signal has to introduce some excess noise. The impossibility of such a noiseless amplifier is rooted in the unitarity and linearity of quantum evolution. A possible way to circumvent this limitation is to interrupt such evolution via a measurement, providing a random outcome able to herald a successful-and noiseless-amplification event. Here we show a successful realization of such an approach; we perform a full characterization of an amplified coherent state using quantum homodyne tomography, and observe a strong heralded amplification, with about a 6 dB gain and a noise level significantly smaller than the minimal allowed for any ordinary phase-independent device.

  2. Wideband pulse amplifiers for the NECTAr chip

    Science.gov (United States)

    Sanuy, A.; Delagnes, E.; Gascon, D.; Sieiro, X.; Bolmont, J.; Corona, P.; Feinstein, F.; Glicenstein, J.-F.; Naumann, C. L.; Nayman, P.; Ribó, M.; Tavernet, J.-P.; Toussenel, F.; Vincent, P.; Vorobiov, S.

    2012-12-01

    The NECTAr collaboration's FE option for the camera of the CTA is a 16 bits and 1-3 GS/s sampling chip based on analog memories including most of the readout functions. This works describes the input amplifiers of the NECTAr ASIC. A fully differential wideband amplifier, with voltage gain up to 20 V/V and a BW of 400 MHz. As it is impossible to design a fully differential OpAmp with an 8 GHz GBW product in a 0.35 CMOS technology, an alternative implementation based on HF linearized transconductors is explored. The output buffer is a class AB miller operational amplifier, with special non-linear current boost.

  3. Wideband pulse amplifiers for the NECTAr chip

    Energy Technology Data Exchange (ETDEWEB)

    Sanuy, A., E-mail: asanuy@ecm.ub.es [Dept. AM i Dept. ECM, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona. Marti i Franques 1, E08028, Barcelona (Spain); Delagnes, E. [IRFU/DSM/CEA, CE-Saclay, Bat. 141 SEN Saclay, F-91191, Gif-sur-Yvette (France); Gascon, D. [Dept. AM i Dept. ECM, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona. Marti i Franques 1, E08028, Barcelona (Spain); Sieiro, X. [Departament d' Electronica, Universitat de Barcelona. Marti i Franques 1, E08028, Barcelona (Spain); Bolmont, J.; Corona, P. [LPNHE, Universite Paris VI and Universite Paris VII and IN2P3/CNRS, Barre 12-22, 1er etage, 4 place Jussieu, 75252 Paris (France); Feinstein, F. [LUPM, Universite Montpellier II and IN2P3/CNRS, CC072, bat. 13, place Eugene Bataillon, 34095 Montpellier (France); Glicenstein, J-F. [IRFU/DSM/CEA, CE-Saclay, Bat. 141 SEN Saclay, F-91191, Gif-sur-Yvette (France); Naumann, C.L.; Nayman, P. [LPNHE, Universite Paris VI and Universite Paris VII and IN2P3/CNRS, Barre 12-22, 1er etage, 4 place Jussieu, 75252 Paris (France); Ribo, M. [Dept. AM i Dept. ECM, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona. Marti i Franques 1, E08028, Barcelona (Spain); and others

    2012-12-11

    The NECTAr collaboration's FE option for the camera of the CTA is a 16 bits and 1-3 GS/s sampling chip based on analog memories including most of the readout functions. This works describes the input amplifiers of the NECTAr ASIC. A fully differential wideband amplifier, with voltage gain up to 20 V/V and a BW of 400 MHz. As it is impossible to design a fully differential OpAmp with an 8 GHz GBW product in a 0.35 CMOS technology, an alternative implementation based on HF linearized transconductors is explored. The output buffer is a class AB miller operational amplifier, with special non-linear current boost.

  4. Design Of A Doherty Power Amplifier For GSM Systems

    Directory of Open Access Journals (Sweden)

    Saad Wasmi Osman

    2013-04-01

    Full Text Available This paper presents the design and analysis of Doherty power amplifier. The Doherty amplifier is used in  a base station for mobile system because of its high efficiency. The class AB power amplifier used in the configuration of the main and auxiliary amplifier. The result obtained shows that the Doherty power amplifier can be used on a wide band spectrum, the amplifier works at 900MHz and has very good power added efficiency (PAE and gain. The amplifier can also work at 1800MHz at input power greater than 20dBm. 

  5. Displacement of microwave squeezed states with Josephson parametric amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Ling; Baust, Alexander; Xie, Edwar; Schwarz, Manuel; Gross, Rudolf [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany); Nanosystems Initiative Munich (NIM), Muenchen (Germany); Fedorov, Kirill; Menzel, Edwin; Marx, Achim [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Betzenbichler, Martin; Pogorzalek, Stefan; Haeberlein, Max; Eder, Peter; Goetz, Jan; Wulschner, Karl Friedrich; Huebl, Hans; Deppe, Frank [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany)

    2015-07-01

    Propagating quantum microwaves are promising building blocks for quantum communication. Interestingly, such itinerant quantum microwaves can be generated in the form of squeezed photon states by Josephson parametric amplifiers (JPA). We employ a specific ''dual-path'' setup for both state reconstruction and JPA characterization. Displacement operations are performed by using a directional coupler after the squeezing. We compare our results with theory predictions. In particular, we discuss our experiments in the context of remote state preparation and quantum teleportation with propagating microwaves.

  6. Implementation of Digital Lock-in Amplifier

    Science.gov (United States)

    Bhattacharyya, Sabyasachi; Nasir Ahmed, Ragib; Bijoy Purkayastha, Basab; Bhattacharyya, Kaustubh

    2016-10-01

    The recovery of signal under the presence of noise is utmost essential for proper communication. The signals corrupted due to noise can be recovered using various techniques. However the weak signals are more prone to noise and hence they can be easily degraded due to noise. In such cases, a digital lock-in amplifier becomes an essential device for recovery of such weak signals. Keeping the cost, speed and other considerations, we will present the implementation of digital lock-in amplifier and how it recovers the weak signal under extreme noisy conditions.

  7. Linear Amplifier Model for Optomechanical Systems

    CERN Document Server

    Botter, Thierry; Brahms, Nathan; Schreppler, Sydney; Stamper-Kurn, Dan M

    2011-01-01

    We model optomechanical systems as linear optical amplifiers. This provides a unified treatment of diverse optomechanical phenomena. We emphasize, in particular, the relationship between ponderomotive squeezing and optomechanically induced transparency, two foci of current research. We characterize the amplifier response to quantum and deliberately applied fluctuations, both optical and mechanical. Further, we apply these results to establish quantum limits on external force sensing both on and off cavity resonance. We find that the maximum sensitivity attained on resonance constitutes an absolute upper limit, not surpassed when detuning off cavity resonance. The theory can be extended to a two-sided cavity with losses and limited detection efficiency.

  8. Analysis of bipolar and CMOS amplifiers

    CERN Document Server

    Sodagar, Amir M

    2007-01-01

    The classical approach to analog circuit analysis is a daunting prospect to many students, requiring tedious enumeration of contributing factors and lengthy calculations. Most textbooks apply this cumbersome approach to small-signal amplifiers, which becomes even more difficult as the number of components increases. Analysis of Bipolar and CMOS Amplifiers offers students an alternative that enables quick and intuitive analysis and design: the analysis-by-inspection method.This practical and student-friendly text demonstrates how to achieve approximate results that fall within an acceptable ran

  9. Double Clad Er-doped Fiber Amplifier

    Institute of Scientific and Technical Information of China (English)

    FU Yong-jun; MAO Xiang-qiao; WEI Huai; LI jian

    2007-01-01

    Presented is a theoretical study of double-clad Er-doped fiber power amplifier(EDFA). Two kinds of double clad fibers(DCF) with rectangular and "flower" inner clad shapes are studied, and these fibers have different coupling constants and propagation losses. We calculate the effective pump power absorption ratio along the fiber with different coupling constants from the first cladding to the doped core and with different propagation losses for the power in the inner cladding. Then the gains of the double clad Er-doped fiber amplifiers versus fiber lengths are calculated using the EDFA model based on propagation and rate equations of a homogeneous, two-level medium.

  10. Optimization of Pr3+:ZBLAN fiber amplifiers

    OpenAIRE

    Pedersen, B.; Miniscalco, J. W.; Quimby, R. S.

    1992-01-01

    Experimental parameters have been measured and used in a quantitative model of Pr3+-doped fluorozirconate fiber amplifiers. The optimum cutoff wavelength was determined to be 800 nm and the gain for 400 mW of pump was found to increase from 12 to 34 dB if the NA was increased from 0.15 to 0.25. Lengthening the metastable state lifetime from 110 to 300 μs would significantly improve amplifier performance while concentration quenching can appreciably degrade it

  11. Dynamic range meter for radiofrequency amplifiers

    Directory of Open Access Journals (Sweden)

    Drozd S. S.

    2009-04-01

    Full Text Available The new measurement setup having increased on 20…30 dB the own dynamic range in comparison with the standard circuit of the dynamic range meter is offered and the rated value of an error bringing by setup in the worst case does not exceed ± 2,8 dB. The measurement setup can be applied also to determinate levels of intermodulation components average power amplifiers and powerful amplifiers of a low-frequency at replacement of the quartz filter on meeting low-frequency the LC-filter and the spectrum analyzer.

  12. Operational amplifier circuits analysis and design

    CERN Document Server

    Nelson, J C C

    1995-01-01

    This book, a revised and updated version of the author's Basic Operational Amplifiers (Butterworths 1986), enables the non-specialist to make effective use of readily available integrated circuit operational amplifiers for a range of applications, including instrumentation, signal generation and processing.It is assumed the reader has a background in the basic techniques of circuit analysis, particularly the use of j notation for reactive circuits, with a corresponding level of mathematical ability. The underlying theory is explained with sufficient but not excessive, detail. A range of compu

  13. Predistortion of a Bidirectional Cuk Audio Amplifier

    DEFF Research Database (Denmark)

    Birch, Thomas Hagen; Nielsen, Dennis; Knott, Arnold

    2014-01-01

    using predistortion. This paper suggests linearizing a nonlinear bidirectional Cuk audio amplifier using an analog predistortion approach. A prototype power stage was built and results show that a voltage gain of up to 9 dB and reduction in THD from 6% down to 3% was obtainable using this approach.......Some non-linear amplifier topologies are capable of providing a larger voltage gain than one from a DC source, which could make them suitable for various applications. However, the non-linearities introduce a significant amount of harmonic distortion (THD). Some of this distortion could be reduced...

  14. 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.

  15. 240 km 10 Gbit/s CS-RZ Repeaterless Transmission over SSMF without Raman or Remotely Pumped Amplifiers

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    10Gbit/s repeaterless transmission over 240km SSMF using CS-RZ format is reported. No Raman or remotely pumped amplifiers are used in this experiment. Effect of channel space in multi-channel application is also investigated.

  16. Optimization of Pr3+:ZBLAN fiber amplifiers

    DEFF Research Database (Denmark)

    Pedersen, B.; Miniscalco, J. W.; Quimby, R. S.

    1992-01-01

    Experimental parameters have been measured and used in a quantitative model of Pr3+-doped fluorozirconate fiber amplifiers. The optimum cutoff wavelength was determined to be 800 nm and the gain for 400 mW of pump was found to increase from 12 to 34 dB if the NA was increased from 0.15 to 0...

  17. CMOS SiPM with integrated amplifier

    Science.gov (United States)

    Schwinger, Alexander; Brockherde, Werner; Hosticka, Bedrich J.; Vogt, Holger

    2017-02-01

    The integration of silicon photomultiplier (SiPM) and frontend electronics in a suitable optoelectronic CMOS process is a promising approach to increase the versatility of single-photon avalanche diode (SPAD)-based singlephoton detectors. By integrating readout amplifiers, the device output capacitance can be reduced to minimize the waveform tail, which is especially important for large area detectors (>10 × 10mm2). Possible architectures include a single readout amplifier for the whole detector, which reduces the output capacitance to 1:1 pF at minimal reduction in detector active area. On the other hand, including a readout amplifier in every SiPM cell would greatly improve the total output capacitance by minimizing the influence of metal routing parasitic capacitance, but requiring a prohibitive amount of detector area. As tradeoff, the proposed detector features one readout amplifier for each column of the detector matrix to allow for a moderate reduction in output capacitance while allowing the electronics to be placed in the periphery of the active detector area. The presented detector with a total size of 1.7 ♢ 1.0mm2 features 400 cells with a 50 μm pitch, where the signal of each column of 20 SiPM cells is summed in a readout channel. The 20 readout channels are subsequently summed into one output channel, to allow the device to be used as a drop-in replacement for commonly used analog SiPMs.

  18. Ultra-low Voltage CMOS Cascode Amplifier

    DEFF Research Database (Denmark)

    Lehmann, Torsten; Cassia, Marco

    2000-01-01

    In this paper, we design a folded cascode operational transconductance amplifier in a standard CMOS process, which has a measured 69 dB DC gain, a 2 MHz bandwidth and compatible input- and output voltage levels at a 1 V power supply. This is done by a novel Current Driven Bulk (CDB) technique...

  19. Holographic preamplifier for a quantum amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Zemskov, K.I.; Kazarian, M.A.; Orlova, N.G.; Liuksiutov, S.F.; Odulov, S.G.

    1988-08-01

    Successive amplification of a weak optical signal was realized experimentally in holographic and quantum amplifiers. The signal was a coherent one with an intensity less than the actual noise of the copper-vapor active medium; the technique involved the use of a coherent holographic preamplifier based on a lithium niobate/sodium photorefractive crystal. 8 references.

  20. Modeling Power Amplifiers using Memory Polynomials

    NARCIS (Netherlands)

    Kokkeler, Andre B.J.

    2005-01-01

    In this paper we present measured in- and output data of a power amplifier (PA). We compare this data with an AM-AM and AM-PM model. We conclude that a more sophisticated PA model is needed to cope with severe memory effects. We suggest to use memory polynomials and introduce two approaches to

  1. Feedback analysis of transimpedance operational amplifier circuits

    DEFF Research Database (Denmark)

    Bruun, Erik

    1993-01-01

    The transimpedance or current feedback operational amplifier (CFB op-amp) is reviewed and compared to a conventional voltage mode op-amp using an analysis emphasizing the basic feedback characteristics of the circuit. With this approach the paradox of the constant bandwidth obtained from CFB op...

  2. A THEORY FOR BROADBAND VARACTOR PARAMETRIC AMPLIFIERS

    Science.gov (United States)

    design and synthesis of broadband varactor parametric amplifiers. The circuit considered in this thesis is that of linear variable capacitors embedded...second and more important inherent property is that, due to the frequency-coupling action of the variable capacitor , the scattering coefficient at the

  3. Offset Correction Techniques for Voltage Sense Amplifiers

    NARCIS (Netherlands)

    Groeneveld, S.

    2006-01-01

    This report deals with offset correction techniques for voltage sense amplifiers and is divided into two different parts: 1) mismatch and 2) offset correction techniques. First a literature study is done on the subject mismatch with specially focus on the future. Mismatch of a transistor is determin

  4. High-Performance Operational and Instrumentation Amplifiers

    NARCIS (Netherlands)

    Shahi, B.

    2015-01-01

    This thesis describes techniques to reduce the offset error in precision instrumentation and operational amplifiers. The offset error which is considered a major error source associated with gain blocks, together with other errors are reviewed. Conventional and newer approaches to remove offset and

  5. Wide-Temperature-Range Integrated Operational Amplifier

    Science.gov (United States)

    Mojarradi, Mohammad; Levanas, Greg; Chen, Yuan; Kolawa, Elizabeth; Cozy, Raymond; Blalock, Benjamin; Greenwell, Robert; Terry, Stephen

    2007-01-01

    A document discusses a silicon-on-insulator (SOI) complementary metal oxide/semiconductor (CMOS) integrated- circuit operational amplifier to be replicated and incorporated into sensor and actuator systems of Mars-explorer robots. This amplifier is designed to function at a supply potential less than or equal to 5.5 V, at any temperature from -180 to +120 C. The design is implemented on a commercial radiation-hard SOI CMOS process rated for a supply potential of less than or equal to 3.6 V and temperatures from -55 to +110 C. The design incorporates several innovations to achieve this, the main ones being the following: NMOS transistor channel lengths below 1 m are generally not used because research showed that this change could reduce the adverse effect of hot carrier injection on the lifetimes of transistors at low temperatures. To enable the amplifier to withstand the 5.5-V supply potential, a circuit topology including cascade devices, clamping devices, and dynamic voltage biasing was adopted so that no individual transistor would be exposed to more than 3.6 V. To minimize undesired variations in performance over the temperature range, the transistors in the amplifier are biased by circuitry that maintains a constant inversion coefficient over the temperature range.

  6. Active Electromagnetic Interference Cancelation for Automotive Switch-Mode Audio Power Amplifiers

    DEFF Research Database (Denmark)

    Knott, Arnold; Pfaffinger, Gerhard; Andersen, Michael A. E.

    2009-01-01

    . Electromagnetic interference between switch-mode audio power amplifiers and receivers show the same physical obstacle as the described ANC endeavors are targeting. The principle of active electromagnetic interference cancelation (AEC) is derived in this paper on a theoretical basis with verifications...... in simulation and experiment. The resulting switch-mode audio power amplifier of this experiment keeps its high efficiency and is able to deliver the signal with less than 0.1 % distortion, while improving the source of electromagnetic interference by 15 dB....

  7. A balanced wide-band amplifier for microwave applications

    Science.gov (United States)

    Panzariu, Mircea; Lupescu, Horia; Dumitrascu, Ana; Tamas, Razvan D.

    2015-02-01

    Due to its better performance, high fiability and large power capability, balanced amplifier is one of the most popular designs used in narrow band applications. However, with a balanced amplifier in class A operation, the band-pass is still narrow with classical coupler [1]. In this paper, we propose a new method for widen the band-pass and linearity of the amplifier, by using two Lange couplers and by adding two drivers, so that small signal could be amplified [2], [3], [4], [5]. The proposed amplifier works in the 0.9 - 2.4 GHz band, with good performances. We also propose an A class X-band amplifier, with Wilkinson power divider used as a combiner and divider. The amplifier will operate at 9,5 GHz with Continuous Wave (C.W). The two methods were validated by simulating the balanced amplifier with Lange coupler and the balanced amplifier with Wilkinson power divider, in class A operation.

  8. Multi-pass amplifier architecture for high power laser systems

    Science.gov (United States)

    Manes, Kenneth R; Spaeth, Mary L; Erlandson, Alvin C

    2014-04-01

    A main amplifier system includes a first reflector operable to receive input light through a first aperture and direct the input light along an optical path. The input light is characterized by a first polarization. The main amplifier system also includes a first polarizer operable to reflect light characterized by the first polarization state. The main amplifier system further includes a first and second set of amplifier modules. Each of the first and second set of amplifier modules includes an entrance window, a quarter wave plate, a plurality of amplifier slablets arrayed substantially parallel to each other, and an exit window. The main amplifier system additionally includes a set of mirrors operable to reflect light exiting the first set of amplifier modules to enter the second set of amplifier modules and a second polarizer operable to reflect light characterized by a second polarization state.

  9. Edge-pumped multi-slab amplifier for inertial fusion energy (IFE)

    Science.gov (United States)

    Li, Min; Zhang, Xiaomin; Li, Mingzhong; Cui, Xudong; Wang, Zhenguo; Yan, Xiongwei; Jiang, Xinying; Zheng, Jiangang

    2016-11-01

    We proposed a novel laser amplifier for inertial fusion energy (IFE) based on an edge-pumped, gas-cooled multi-slab architecture. Compared to the face-pumped laser amplifiers for IFE, this architecture enables the pump, coolant and laser propagating orthogonally in the amplifier, thereby decoupling them in space and being beneficial to construction of the amplifier. To satisfy the high efficiency required for IFE, high-irradiance rectangle-waveguide coupled diode laser arrays are employed in the edge-pumped architecture and the pump light will be homogenized by total internal reflection. A traverse gradient doping profile is applied to the gain media, thus the pump absorption and gain uniformity can be separately optimized. Furthermore, the laser beam normal to the surfaces of the gas-cooled slabs will experience minimum thermal wavefront distortions in the amplifier head and ensure high beam quality. Since each slab has its own pump source and uniform gain in the aperture, power scaling can be easily achieved by placing identical slabs along the laser beam axis. Our investigations might provide an efficient and convenient way to design and optimize the amplifiers for IFE.

  10. The warm, rich sound of valve guitar amplifiers

    Science.gov (United States)

    Keeports, David

    2017-03-01

    Practical solid state diodes and transistors have made glass valve technology nearly obsolete. Nevertheless, valves survive largely because electric guitar players much prefer the sound of valve amplifiers to the sound of transistor amplifiers. This paper discusses the introductory-level physics behind that preference. Overdriving an amplifier adds harmonics to an input sound. While a moderately overdriven valve amplifier produces strong even harmonics that enhance a sound, an overdriven transistor amplifier creates strong odd harmonics that can cause dissonance. The functioning of a triode valve explains its creation of even and odd harmonics. Music production software enables the examination of both the wave shape and the harmonic content of amplified sounds.

  11. Low phase noise oscillator using two parallel connected amplifiers

    Science.gov (United States)

    Kleinberg, Leonard L.

    1987-01-01

    A high frequency oscillator is provided by connecting two amplifier circuits in parallel where each amplifier circuit provides the other amplifier circuit with the conditions necessary for oscillation. The inherent noise present in both amplifier circuits causes the quiescent current, and in turn, the generated frequency, to change. The changes in quiescent current cause the transconductance and the load impedance of each amplifier circuit to vary, and this in turn results in opposing changes in the input susceptance of each amplifier circuit. Because the changes in input susceptance oppose each other, the changes in quiescent current also oppose each other. The net result is that frequency stability is enhanced.

  12. Amplified spontaneous emission spectrum and gain characteristic of a two-electrode semiconductor optical amplifier*

    Institute of Scientific and Technical Information of China (English)

    Wang Hanchao; Huang Lirong; Shi Zhongwei

    2011-01-01

    A two-electrode multi-quantum-well semiconductor optical amplifier is designed and fabricated. The amplified spontaneous emission (ASE) spectrum and gain were measured and analyzed. It is shown that the ASE spectrum and gain characteristic are greatly influenced by the distribution of the injection current density. By changing the injection current density of two electrodes, the full width at half maximum, peak wavelength, peak power of the ASE spectrum and the gain characteristic can be easily controlled.

  13. High-gain cryogenic amplifier assembly employing a commercial CMOS operational amplifier.

    Science.gov (United States)

    Proctor, J E; Smith, A W; Jung, T M; Woods, S I

    2015-07-01

    We have developed a cryogenic amplifier for the measurement of small current signals (10 fA-100 nA) from cryogenic optical detectors. Typically operated with gain near 10(7) V/A, the amplifier performs well from DC to greater than 30 kHz and exhibits noise level near the Johnson limit. Care has been taken in the design and materials to control heat flow and temperatures throughout the entire detector-amplifier assembly. A simple one-board version of the amplifier assembly dissipates 8 mW to our detector cryostat cold stage, and a two-board version can dissipate as little as 17 μW to the detector cold stage. With current noise baseline of about 10 fA/(Hz)(1/2), the cryogenic amplifier is generally useful for cooled infrared detectors, and using blocked impurity band detectors operated at 10 K, the amplifier enables noise power levels of 2.5 fW/(Hz)(1/2) for detection of optical wavelengths near 10 μm.

  14. Preliminary design studies for a 100 MW Energy Amplifier prototype

    CERN Document Server

    Abánades, A

    2000-01-01

    The Energy Amplifier (EA) is a new concept of fission system based on a subcritical assembly sustained with the neutrons generated by proton beam impact on a heavy element (spallation). This concept, proposed by the Nobel Laureate C. Rubbia (Rubbia, 1995), has remarkable capabilities in the nuclear energy field. First, it can be used to transmute radioactive wastes with a high efficiency alleviating the requirements of the geological repositories, and, second, it provides a massive energy source with the intrinsic safety derived from the use of a subcritical system and an almost null production of long-lived radioactive wastes. EA concept principles have been successfully tested by two experiments at CERN: FEAT (Andriamonge, 1995), that proved there is a net energy gain, by comparing the energy needed by the accelerator with the generated one by fission in the subcritical system. The second experiment, TARC (Abanades, 1997; Arnould, 1999) demonstrated the capability to transmute radioactive elements. The next...

  15. Breadboard Amplifier: Building and Using Simple Electrophysiology Equipment.

    Science.gov (United States)

    Crisp, Kevin M; Lin, Hunter; Prosper, Issa

    2016-01-01

    Electrophysiology is a valuable skill for the neuroscientist, but the learning curve for students can be steep. Here we describe a very simple electromyography (EMG) amplifier that can be built from scratch by students with no electronics experience in about 30 minutes, making it ideal for incorporating into a laboratory activity. With few parts and no adjustments except the gain, students can begin physiology experiments quickly while having the satisfaction of having built the equipment themselves. Because the output of the circuit goes to a computer sound card, students can listen to electrophysiological activity as they see it on the computer screen, a feature many of our students greatly appreciated. Various applications are discussed, including dual channel recording, using streaming media platforms with remote lab partners and acquiring data in the field on a smart phone. Our students reported that they enjoyed being able to build a working device and using it to record from their own muscles.

  16. Automatic alignment of double optical paths in excimer laser amplifier

    Science.gov (United States)

    Wang, Dahui; Zhao, Xueqing; Hua, Hengqi; Zhang, Yongsheng; Hu, Yun; Yi, Aiping; Zhao, Jun

    2013-05-01

    A kind of beam automatic alignment method used for double paths amplification in the electron pumped excimer laser system is demonstrated. In this way, the beams from the amplifiers can be transferred along the designated direction and accordingly irradiate on the target with high stabilization and accuracy. However, owing to nonexistence of natural alignment references in excimer laser amplifiers, two cross-hairs structure is used to align the beams. Here, one crosshair put into the input beam is regarded as the near-field reference while the other put into output beam is regarded as the far-field reference. The two cross-hairs are transmitted onto Charge Coupled Devices (CCD) by image-relaying structures separately. The errors between intersection points of two cross-talk images and centroid coordinates of actual beam are recorded automatically and sent to closed loop feedback control mechanism. Negative feedback keeps running until preset accuracy is reached. On the basis of above-mentioned design, the alignment optical path is built and the software is compiled, whereafter the experiment of double paths automatic alignment in electron pumped excimer laser amplifier is carried through. Meanwhile, the related influencing factors and the alignment precision are analyzed. Experimental results indicate that the alignment system can achieve the aiming direction of automatic aligning beams in short time. The analysis shows that the accuracy of alignment system is 0.63μrad and the beam maximum restoration error is 13.75μm. Furthermore, the bigger distance between the two cross-hairs, the higher precision of the system is. Therefore, the automatic alignment system has been used in angular multiplexing excimer Main Oscillation Power Amplification (MOPA) system and can satisfy the requirement of beam alignment precision on the whole.

  17. Behavioral modeling of Digitally Adjustable Current Amplifier

    Directory of Open Access Journals (Sweden)

    Josef Polak

    2015-03-01

    Full Text Available This article presents the digitally adjustable current amplifier (DACA and its analog behavioral model (ABM, which is suitable for both ideal and advanced analyses of the function block using DACA as active element. There are four levels of this model, each being suitable for simulation of a certain degree of electronic circuits design (e.g. filters, oscillators, generators. Each model is presented through a schematic wiring in the simulation program OrCAD, including a description of equations representing specific functions in the given level of the simulation model. The design of individual levels is always verified using PSpice simulations. The ABM model has been developed based on practically measured values of a number of DACA amplifier samples. The simulation results for proposed levels of the ABM model are shown and compared with the results of the real easurements of the active element DACA.

  18. Fundamentals of fiber lasers and fiber amplifiers

    CERN Document Server

    Ter-Mikirtychev, Valerii (Vartan)

    2014-01-01

    This book covers the fundamental aspects of fiber lasers and fiber amplifiers, and includes a wide range of material from laser physics fundamentals to state-of-the-art topics in this rapidly growing field of quantum electronics. Emphasis is placed on the nonlinear processes taking place in fiber lasers and amplifiers, their similarities, differences to, and their advantages over other solid-state lasers. The reader will learn basic principles of solid-state physics and optical spectroscopy of laser active centers in fibers, main operational laser regimes, and practical recommendations and suggestions on fiber laser research, laser applications, and laser product development. The book will be useful for students, researchers, and professionals who work with lasers, in the optical communications, chemical and biological industries, etc.

  19. Linear control of oscillator and amplifier flows*

    Science.gov (United States)

    Schmid, Peter J.; Sipp, Denis

    2016-08-01

    Linear control applied to fluid systems near an equilibrium point has important applications for many flows of industrial or fundamental interest. In this article we give an exposition of tools and approaches for the design of control strategies for globally stable or unstable flows. For unstable oscillator flows a feedback configuration and a model-based approach is proposed, while for stable noise-amplifier flows a feedforward setup and an approach based on system identification is advocated. Model reduction and robustness issues are addressed for the oscillator case; statistical learning techniques are emphasized for the amplifier case. Effective suppression of global and convective instabilities could be demonstrated for either case, even though the system-identification approach results in a superior robustness to off-design conditions.

  20. High Gain Amplifier with Enhanced Cascoded Compensation

    Directory of Open Access Journals (Sweden)

    J. Lemus-Lopez

    2014-04-01

    Full Text Available A two-stage CMOS operational amplifier with both, gain-boosting and indirect current feedback frequency compensation performed by means of regulated cascode amplifiers, is presented. By using quasi-floating-gate transistors (QFGT the supply requirements, the number of capacitors and the size of the compensation capacitors respect to other Miller schemes are reduced. A prototype was fabricated using a 0.5 μm technology, resulting, for a load of 45 pF and supply voltage of 1.65 V, in open-loop-gain of 129 dB, 23 MHz of gain-bandwidth product, 60o phase margin, 675 μW power consumption and 1% settling time of 28 ns.

  1. Noise Gain Features of Fiber Raman Amplifier

    Directory of Open Access Journals (Sweden)

    Georgii S. Felinskyi

    2016-01-01

    Full Text Available The formation dynamics of the optical noise in a silica single mode fiber (SMF as function of the pump power variation in the counter pumped fiber Raman amplifier (FRA is experimentally studied. The ratio between the power of amplified spontaneous emission and the power of incoherent optical noise is quantitatively determined by detailed analysis of experimental data in the pump powers range of 100–300 mW within the full band of Stokes frequencies, including FRA working wavelengths over the C + L transparency windows. It is found out the maximum of Raman gain coefficient for optical noise does not exceed ~60% of corresponding peak at the gain profile maximum of coherent signal. It is shown that the real FRA noise figure may be considerably less than 3 dB over a wide wavelength range (100 nm at a pump power of several hundreds of mW.

  2. Cryogenic cooling for high power laser amplifiers

    Directory of Open Access Journals (Sweden)

    Perin J.P.

    2013-11-01

    Full Text Available Using DPSSL (Diode Pumped Solid State Lasers as pumping technology, PW-class lasers with enhanced repetition rates are developed. Each of the Yb YAG amplifiers will be diode-pumped at a wavelength of 940 nm. This is a prerequisite for achieving high repetition rates (light amplification duration 1 millisecond and repetition rate 10 Hz. The efficiency of DPSSL is inversely proportional to the temperature, for this reason the slab amplifier have to be cooled at a temperature in the range of 100 K–170 K with a heat flux of 1 MW*m−2. This paper describes the thermo-mechanical analysis for the design of the amplification laser head, presents a preliminary proposal for the required cryogenic cooling system and finally outlines the gain of cryogenic operation for the efficiency of high pulsed laser.

  3. Behavioral modeling of Digitally Adjustable Current Amplifier

    OpenAIRE

    Josef Polak; Lukas Langhammer; Jan Jerabek

    2015-01-01

    This article presents the digitally adjustable current amplifier (DACA) and its analog behavioral model (ABM), which is suitable for both ideal and advanced analyses of the function block using DACA as active element. There are four levels of this model, each being suitable for simulation of a certain degree of electronic circuits design (e.g. filters, oscillators, generators). Each model is presented through a schematic wiring in the simulation program OrCAD, including a description of equat...

  4. Self-amplifying mRNA vaccines.

    Science.gov (United States)

    Brito, Luis A; Kommareddy, Sushma; Maione, Domenico; Uematsu, Yasushi; Giovani, Cinzia; Berlanda Scorza, Francesco; Otten, Gillis R; Yu, Dong; Mandl, Christian W; Mason, Peter W; Dormitzer, Philip R; Ulmer, Jeffrey B; Geall, Andrew J

    2015-01-01

    This chapter provides a brief introduction to nucleic acid-based vaccines and recent research in developing self-amplifying mRNA vaccines. These vaccines promise the flexibility of plasmid DNA vaccines with enhanced immunogenicity and safety. The key to realizing the full potential of these vaccines is efficient delivery of nucleic acid to the cytoplasm of a cell, where it can amplify and express the encoded antigenic protein. The hydrophilicity and strong net negative charge of RNA impedes cellular uptake. To overcome this limitation, electrostatic complexation with cationic lipids or polymers and physical delivery using electroporation or ballistic particles to improve cellular uptake has been evaluated. This chapter highlights the rapid progress made in using nonviral delivery systems for RNA-based vaccines. Initial preclinical testing of self-amplifying mRNA vaccines has shown nonviral delivery to be capable of producing potent and robust innate and adaptive immune responses in small animals and nonhuman primates. Historically, the prospect of developing mRNA vaccines was uncertain due to concerns of mRNA instability and the feasibility of large-scale manufacturing. Today, these issues are no longer perceived as barriers in the widespread implementation of the technology. Currently, nonamplifying mRNA vaccines are under investigation in human clinical trials and can be produced at a sufficient quantity and quality to meet regulatory requirements. If the encouraging preclinical data with self-amplifying mRNA vaccines are matched by equivalently positive immunogenicity, potency, and tolerability in human trials, this platform could establish nucleic acid vaccines as a versatile new tool for human immunization. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Fast Electrocardiogram Amplifier Recovery after Defibrillation Shock

    Directory of Open Access Journals (Sweden)

    Ivan Dotsinsky

    2005-04-01

    Full Text Available A procedure for fast ECG amplifier recovery after defibrillation shocks was developed and simulated in the MATLAB environment. Exponentially decaying post-shock voltages have been recorded. Signals from the AHA database are taken and mixed with the recorded exponential disturbances. The algorithm applies moving averaging (comb filter on the compound input signal, thereby obtaining the samples of the disturbance. They are currently subtracted from the input signal. The results obtained show that its recovery is practically instantaneous.

  6. Electrically Pumped Vertical-Cavity Amplifiers

    DEFF Research Database (Denmark)

    Greibe, Tine

    2007-01-01

    In this work, the design of electrically pumped vertical cavity semiconductor optical amplifiers (eVCAs) for use in a mode-locked external-cavity laser has been developed, investigated and analysed. Four different eVCAs, one top-emitting and three bottom emitting structures, have been designed...... and discussed. The thesis concludes with recommendations for further work towards the realisation of compact electrically pumped mode-locked vertical externalcavity surface emitting lasers....

  7. Design and simulation of a gyroklystron amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Chauhan, M. S., E-mail: mschauhan.rs.ece@iitbhu.ac.in; Swati, M. V.; Jain, P. K. [Centre of Research in Microwave Tubes, Department of Electronics Engineering, Indian Institute of Technology, Banaras Hindu University, Varanasi 221005 (India)

    2015-03-15

    In the present paper, a design methodology of the gyroklystron amplifier has been described and subsequently used for the design of a typically selected 200 kW, Ka-band, four-cavity gyroklystron amplifier. This conceptual device design has been validated through the 3D particle-in-cell (PIC) simulation and nonlinear analysis. Commercially available PIC simulation code “MAGIC” has been used for the electromagnetic study at the different location of the device RF interaction structure for the beam-absent case, i.e., eigenmode study as well as for the electron beam and RF wave interaction behaviour study in the beam present case of the gyroklystron. In addition, a practical problem of misalignment of the RF cavities with drift tubes within the tube has been also investigated and its effect on device performance studied. The analytical and simulation results confirmed the validity of the gyroklystron device design. The PIC simulation results of the present gyroklystron produced a stable RF output power of ∼218 kW for 0% velocity spread at 35 GHz, with ∼45 dB gain, 37% efficiency, and a bandwidth of 0.3% for a 70 kV, 8.2 A gyrating electron beam. The simulated values of RF output power have been found in agreement with the nonlinear analysis results within ∼5%. Further, the PIC simulation has been extended to study a practical problem of misalignment of the cavities axis and drift tube axis of the gyroklystron amplifier and found that the RF output power is more sensitive to misalignments in comparison to the device bandwidth. The present paper, gyroklystron device design, nonlinear analysis, and 3D PIC simulation using commercially available code had been systematically described would be of use to the high-power gyro-amplifier tube designers and research scientists.

  8. Amplifying the Hawking Signal in BECs

    Directory of Open Access Journals (Sweden)

    Roberto Balbinot

    2014-01-01

    Full Text Available We consider simple models of Bose-Einstein condensates to study analog pair-creation effects, namely, the Hawking effect from acoustic black holes and the dynamical Casimir effect in rapidly time-dependent backgrounds. We also focus on a proposal by Cornell to amplify the Hawking signal in density-density correlators by reducing the atoms’ interactions shortly before measurements are made.

  9. High-Performance Operational and Instrumentation Amplifiers

    OpenAIRE

    Shahi, B.

    2015-01-01

    This thesis describes techniques to reduce the offset error in precision instrumentation and operational amplifiers. The offset error which is considered a major error source associated with gain blocks, together with other errors are reviewed. Conventional and newer approaches to remove offset and low frequency noise are discussed, with a focus on the work of this thesis “Chopper-Stabilized Auto-Zeroed Chopper Instrumentation Amplifiers”. The technique is demonstrated through the application...

  10. Transportable setup for amplifier phase fidelity measurements

    OpenAIRE

    Troebs, Michael; Bogan, C.; Barke, S.; Kuehn, G.; Reiche, J.; Heinzel, Gerhard; Danzmann, Karsten

    2015-01-01

    One possible laser source for the Laser Interferometer Space Antenna (LISA) consists of an Ytterbium-doped fiber amplifier originally developed for inter-satellite communication, seeded by the laser used for the technology demonstrator mission LISA Pathfinder. LISA needs to transmit clock information between its three spacecraft to correct for phase noise between the clocks on the individual spacecraft. For this purpose phase modulation sidebands at GHz frequencies will be imprinted on the la...

  11. Short wavelength regenerative amplifier free electron lasers

    OpenAIRE

    Dunning, D J; McNeil, B. W. J.; Thompson, N. R.

    2008-01-01

    In this paper we discuss extending the operating wavelength range of tunable Regenerative Amplifier FELs to shorter wavelengths than current design proposals, notably into the XUV regions of the spectrum and beyond where the reflectivity of broadband optics is very low. Simulation studies are presented which demonstrate the development of good temporal coherence in generic systems with a broadband radiation feedback of less than one part in ten thousand.

  12. Charge sensitive amplifies. The state of arts

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Kunishiro [Clear Pulse Co., Tokyo (Japan)

    1996-07-01

    In the radiation detectors, signals are essentially brought with charges produced by radiation, then it is naturally the best way to use a charge sensitive amplifier (CSA) system to extract those signals. The CSA is thought to be the best amplifier suitable to almost all the radiation detectors, if neglecting economical points of view. The CSA has been only applied to special fields like radiation detection because the concept of `charges` is not so universal against the concepts of `voltage` and `current`. The CSA, however, is low in noise and a high speed amplifier and may be applicable not only to radiation measurement but also piezoelectric devices and also bolometers. In this article, noise in the CSA, basic circuit on the CSA, concepts of `equivalent noise charge` (ENC), a method for the ENC, and importance of the `open-loop gain` in the CSA to achieve better performance of it and how to realize in a practical CSA were described. And, characteristics on a counting rate of the CSA, various circuit used in the CSA, and CSAs which are commercially available at present and special purpose CSAs were also introduced. (G.K.)

  13. Parallel reservoir computing using optical amplifiers.

    Science.gov (United States)

    Vandoorne, Kristof; Dambre, Joni; Verstraeten, David; Schrauwen, Benjamin; Bienstman, Peter

    2011-09-01

    Reservoir computing (RC), a computational paradigm inspired on neural systems, has become increasingly popular in recent years for solving a variety of complex recognition and classification problems. Thus far, most implementations have been software-based, limiting their speed and power efficiency. Integrated photonics offers the potential for a fast, power efficient and massively parallel hardware implementation. We have previously proposed a network of coupled semiconductor optical amplifiers as an interesting test case for such a hardware implementation. In this paper, we investigate the important design parameters and the consequences of process variations through simulations. We use an isolated word recognition task with babble noise to evaluate the performance of the photonic reservoirs with respect to traditional software reservoir implementations, which are based on leaky hyperbolic tangent functions. Our results show that the use of coherent light in a well-tuned reservoir architecture offers significant performance benefits. The most important design parameters are the delay and the phase shift in the system's physical connections. With optimized values for these parameters, coherent semiconductor optical amplifier (SOA) reservoirs can achieve better results than traditional simulated reservoirs. We also show that process variations hardly degrade the performance, but amplifier noise can be detrimental. This effect must therefore be taken into account when designing SOA-based RC implementations.

  14. Transistor circuit increases range of logarithmic current amplifier

    Science.gov (United States)

    Gilmour, G.

    1966-01-01

    Circuit increases the range of a logarithmic current amplifier by combining a commercially available amplifier with a silicon epitaxial transistor. A temperature compensating network is provided for the transistor.

  15. Noise and saturation properties of semiconductor quantum dot optical amplifiers

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Mørk, Jesper

    2002-01-01

    We present a detailed theoretical analysis of quantum dot optical amplifiers. Due to the presence of a reservoir of wetting layer states, the saturation and noise properties differ markedly from bulk or QW amplifiers and may be significantly improved.......We present a detailed theoretical analysis of quantum dot optical amplifiers. Due to the presence of a reservoir of wetting layer states, the saturation and noise properties differ markedly from bulk or QW amplifiers and may be significantly improved....

  16. Polarization of Tapered Semiconductor Travelling-Wave Amplifiers

    Institute of Scientific and Technical Information of China (English)

    Huang Dexiu; Li Hong

    2001-01-01

    The polarization of a tapered semi-conductor travelling-wave amplifier has been investigated with the transfer matrix method based on convective equation. It is shown that the apparent polarization mode competition exists, and polarization-independent tapered semiconductor travellingwave amplifiers can be obtained through the optimization of amplifier parameters.

  17. An integrated charge amplifier for a pyroelectric sensor

    NARCIS (Netherlands)

    Setiadi, D.; Armitage, A.; Binnie, T.D.; Regtien, P.P.L.; Sarro, P.M.

    1997-01-01

    This paper presents an integrated charge amplifier that measures a small charge. This charge is generated by a pyroelectric detector. The charge amplifier consists of a single-stage c-annon source configuration with a passive feedback network. The charge amplifier has a bandwidth of 700 kHz and an o

  18. The Dynamics of Semiconductor Optical Amplifiers – Modeling and Applications

    DEFF Research Database (Denmark)

    Mørk, Jesper; Nielsen, Mads Lønstrup; Berg, Tommy Winther

    2003-01-01

    The importance of semiconductor optical amplifiers is discussed. A semiconductor optical amplifier (SOA) is a semiconductor laser with anti-reflection coated facets that amplifies an injected light signal by means of stimulated emission. SOAs have a number of unique properties that open up...

  19. Differential transimpedance amplifier circuit for correlated differential amplification

    Science.gov (United States)

    Gresham, Christopher A.; Denton, M. Bonner; Sperline, Roger P.

    2008-07-22

    A differential transimpedance amplifier circuit for correlated differential amplification. The amplifier circuit increase electronic signal-to-noise ratios in charge detection circuits designed for the detection of very small quantities of electrical charge and/or very weak electromagnetic waves. A differential, integrating capacitive transimpedance amplifier integrated circuit comprising capacitor feedback loops performs time-correlated subtraction of noise.

  20. Cleanliness improvements of NIF (National Ignition Facility) amplifiers as compared to previous large-scale lasers

    Energy Technology Data Exchange (ETDEWEB)

    Honig, J

    2004-06-09

    Prior to the recent commissioning of the first NIF (National Ignition Facility) beamline, full-scale laser-amplifier-glass cleanliness experiments were performed. Aerosol measurements and obscuration data acquired using a modified flatbed scanner compare favorably to historical large-scale lasers and indicate that NIF is the cleanest large-scale laser built to date.

  1. A low-voltage sense amplifier with two-stage operational amplifier clamping for flash memory

    Science.gov (United States)

    Guo, Jiarong

    2017-04-01

    A low-voltage sense amplifier with reference current generator utilizing two-stage operational amplifier clamp structure for flash memory is presented in this paper, capable of operating with minimum supply voltage at 1 V. A new reference current generation circuit composed of a reference cell and a two-stage operational amplifier clamping the drain pole of the reference cell is used to generate the reference current, which avoids the threshold limitation caused by current mirror transistor in the traditional sense amplifier. A novel reference voltage generation circuit using dummy bit-line structure without pull-down current is also adopted, which not only improves the sense window enhancing read precision but also saves power consumption. The sense amplifier was implemented in a flash realized in 90 nm flash technology. Experimental results show the access time is 14.7 ns with power supply of 1.2 V and slow corner at 125 °C. Project supported by the National Natural Science Fundation of China (No. 61376028).

  2. The Paralleling of High Power High Frequency Amplifier Based on Synchronous and Asynchronous Control

    Institute of Scientific and Technical Information of China (English)

    程荣仓; 刘正之

    2004-01-01

    The vertical position of plasma in the HT-7U Tokamak is inherently unstable. In order to realize active stabilization, the response rate of the high-power high-frequency amplifier feeding the active control coils must be fast enough. This paper analyzes the paralleling scheme of the power amplifier through two kinds of control mode. One is the synchronous control; the other is the asynchronous control. Via the comparison of the two kinds of control mode, both of their characteristics are given in the text. At last, the analyzed result is verified by a small power experiment.

  3. Time-domain model of quantum-dot semiconductor optical amplifiers for wideband optical signals.

    Science.gov (United States)

    Puris, D; Schmidt-Langhorst, C; Lüdge, K; Majer, N; Schöll, E; Petermann, K

    2012-11-19

    We present a novel theoretical time-domain model for a quantum dot semiconductor optical amplifier, that allows to simulate subpicosecond pulse propagation including power-based and phase-based effects. Static results including amplified spontaneous emission spectra, continuous wave amplification, and four-wave mixing experiments in addition to dynamic pump-probe simulations are presented for different injection currents. The model uses digital filters to describe the frequency dependent gain and microscopically calculated carrier-carrier scattering rates for the interband carrier dynamics. It can be used to calculate the propagation of multiple signals with different wavelengths or one wideband signal with high bitrate.

  4. Enhanced propagation of photon density waves in random amplifying media

    CERN Document Server

    Renthlei, Lalruatfela; Ramakrishna, S A

    2013-01-01

    We demonstrate enhanced wave-like character of diffuse photon density waves (DPDW) in an amplifying random medium. The amplifying nature makes it contingent to choose the wave solution that grows inside the amplifying medium, and has a propagation vector pointing opposite to the growth direction. This results in negative refraction of the DPDW at an absorbing-amplifying random medium interface as well as the possibility of supporting "anti"-surface-like modes at the interface. A slab of amplifying random medium sandwiched between two absorbing random media supports waveguide resonances that can be utilized to extend the imaging capabilities of DPDW.

  5. Enhanced propagation of photon density waves in random amplifying media

    Science.gov (United States)

    Renthlei, Lalruatfela; Wanare, Harshawardhan; Ramakrishna, S. Anantha

    2015-04-01

    We demonstrate enhanced wavelike character of diffuse photon density waves (DPDW) in an amplifying random medium. The amplifying nature makes it necessary to choose the wave solution that grows inside the amplifying medium, and has a propagation vector pointing opposite to the growth direction. This results in negative refraction of the DPDW at an absorbing-amplifying random medium interface as well as the possibility of supporting "anti"-surface-like modes at the interface. A slab of an amplifying random medium sandwiched between two absorbing random media supports waveguide resonances that can be utilized to extend the imaging capabilities of DPDW.

  6. Note: A high dynamic range, linear response transimpedance amplifier.

    Science.gov (United States)

    Eckel, S; Sushkov, A O; Lamoreaux, S K

    2012-02-01

    We have built a high dynamic range (nine decade) transimpedance amplifier with a linear response. The amplifier uses junction-gate field effect transistors (JFETs) to switch between three different resistors in the feedback of a low input bias current operational amplifier. This allows for the creation of multiple outputs, each with a linear response and a different transimpedance gain. The overall bandwidth of the transimpedance amplifier is set by the bandwidth of the most sensitive range. For our application, we demonstrate a three-stage amplifier with transimpedance gains of approximately 10(9)Ω, 3 × 10(7)Ω, and 10(4)Ω with a bandwidth of 100 Hz.

  7. Bio-isolated dc operational amplifier. [for bioelectric measurements

    Science.gov (United States)

    Lee, R. D. (Inventor)

    1974-01-01

    A bio-isolated dc operational amplifier is described for use in making bioelectrical measurements of a patient while providing isolation of the patient from electrical shocks. The circuit contains a first operational amplifier coupled to the patient with its output coupled in a forward loop through a first optic coupler to a second operational amplifier. The output of the second operational amplifier is coupled to suitable monitoring circuitry via a feedback circuit including a second optic coupler to the input of the first operational amplifier.

  8. Time amplifying techniques towards atomic time resolution

    Institute of Scientific and Technical Information of China (English)

    LI JingZhen

    2009-01-01

    High speed imaging technology has opened applications in many fields,such as collision,detonating,high voltage discharge,disintegration and transfer of phonon and exciton in solid,photosynthesis primitive reaction,and electron dynamics inside atom shell.In principle,all of the transient processes need to be explained theoretically and,st the same time,the time amplifying technique is required for observations of these processes.The present review concerns the atomic time amplifying mechanism of optical information and the extremely-high speed imaging methods,which are expressed in terms of the short time amplifying techniques.It is well-known that for extremely-high speed imaging with the converter tube,the temporal resolution is in the order of sub-picosecond of the streak imaging,and the imaging frequency is 6×10~8-5×10~9 fps(frame per second)of the frame imaging.On the other hand,for the tubeless extremely-high speed imaging,the imaging frequency is 10~7-10~(14) fps,and its mechanism of forming high speed and framing could involve a lot of factors of the light under investigation,for instance,light speed,light parallelism,the parameters of light wave such as amplitude,phase,polarization and wavelength,and even quantum properties of photon.In the cascaded system of electromagnetic wave and particle wave,it is possible to simultaneously realize extremely-high resolution in time and space,which is higher than a kite resolution.Then it would be possible to break the limit of the Heisenberg uncertainty relation of the optical frequency band.

  9. Time amplifying techniques towards atomic time resolution

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    High speed imaging technology has opened applications in many fields,such as collision,detonating, high voltage discharge,disintegration and transfer of phonon and exciton in solid,photosynthesis primitive reaction,and electron dynamics inside atom shell.In principle,all of the transient processes need to be explained theoretically and,at the same time,the time amplifying technique is required for observations of these processes.The present review concerns the atomic time amplifying mechanism of optical information and the extremely-high speed imaging methods,which are expressed in terms of the short time amplifying techniques.It is well-known that for extremely-high speed imaging with the converter tube,the temporal resolution is in the order of sub-picosecond of the streak imaging,and the imaging frequency is 6×10 8 ―5×10 9 fps(frame per second)of the frame imaging.On the other hand,for the tubeless extremely-high speed imaging,the imaging frequency is 10 7 ―10 14 fps,and its mechanism of forming high speed and framing could involve a lot of factors of the light under investigation,for instance,light speed,light parallelism,the parameters of light wave such as amplitude,phase,polari- zation and wavelength,and even quantum properties of photon.In the cascaded system of electro- magnetic wave and particle wave,it is possible to simultaneously realize extremely-high resolution in time and space,which is higher than a kite resolution.Then it would be possible to break the limit of the Heisenberg uncertainty relation of the optical frequency band.

  10. Assessing the reliability of amplified RNA used in microarrays: a DUMB table approach.

    Science.gov (United States)

    Bearden, Edward D; Simpson, Pippa M; Peterson, Charlotte A; Beggs, Marjorie L

    2006-01-01

    A certain minimal amount of RNA from biological samples is necessary to perform a microarray experiment with suitable replication. In some cases, the amount of RNA available is insufficient, necessitating RNA amplification prior to target synthesis. However, there is some uncertainty about the reliability of targets that have been generated from amplified RNA, because of nonlinearity and preferential amplification. This current work develops a straightforward strategy to assess the reliability of microarray data obtained from amplified RNA. The tabular method we developed, which utilises a Down-Up-Missing-Below (DUMB) classification scheme, shows that microarrays generated with amplified RNA targets are reliable within constraints. There was an increase in false negatives because of the need for increased filtering. Furthermore, this analysis method is generic and can be broadly applied to evaluate all microarray data. A copy of the Microsoft Excel spreadsheet is available upon request from Edward Bearden.

  11. Investigations of electronic amplifiers supplying a piezobimorph actuator

    Science.gov (United States)

    Milecki, Andrzej; Regulski, Roman

    2016-10-01

    Piezoelectric bending actuators, also known as bimorphs, are characterized by very good dynamic properties and by displacements in a range of a few millimeters. Therefore these actuators are used in a wide range of applications. However their usage is limited because they require supplying amplifiers with output voltage of about 200 V, which are rather expensive. This paper presents investigation results of such amplifiers with high voltage output. The model of a piezobending actuator is proposed and implemented in Matlab-Simulink software in order to simulate the behavior of the actuator supplied by the amplifiers. The simulation results are presented and compared with investigation results of high voltage amplifier used for supplying a piezoactuator. The influence of current limitation of operational amplifier on the actuator current is tested. Finally, a low cost audio power amplifier is proposed to control the piezobender actuator (as a cheaper alternative to the high-voltage amplifier) and its investigations results are presented in the paper.

  12. Low power RF amplifier circuit for ion trap applications

    Science.gov (United States)

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

    2016-09-01

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

  13. On Distortion in Digital Microwave Power Amplifiers

    Science.gov (United States)

    Al-Mozani, Dhamia; Wentzel, Andreas; Heinrich, Wolfgang

    2017-01-01

    In this paper, a first study of distortion in digital power amplifiers (PA) is presented. The work is based on a voltage mode class-S PA with a GaN MMIC for the 900 MHz frequency band. The investigation focuses on the quasi-static amplitude-to-amplitude (AM-AM) and amplitude-to-phase (AM-PM) distortions. Different digital modulation schemes are applied and studied versus output power back-off. This includes two pulse-width modulation (PWM) versions as well as band-pass delta-sigma (BPDS) modulation. The results are verified by measurement data.

  14. Feedback analysis of transimpedance operational amplifier circuits

    OpenAIRE

    Bruun, Erik

    1993-01-01

    The transimpedance or current feedback operational amplifier (CFB op-amp) is reviewed and compared to a conventional voltage mode op-amp using an analysis emphasizing the basic feedback characteristics of the circuit. With this approach the paradox of the constant bandwidth obtained from CFB op-amps is explained. It is demonstrated in a simple manner that the constant gain-bandwidth product of the conventional op-amp and the constant bandwidth of the CFB op-amp are both in accordance with bas...

  15. Gain flattened distributed fiber raman amplifiers

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    An S band and a C band distributed fiber Raman amplifiers (DFRAs) with flattened gain and compensated dispersion have been studied and implemented with 1 427 nm and 1 455 nm mono-wavelength fiber Raman lasers as the pumped sources respectively. The gain of single-wave pumped S band and C band can reach 10 dB and 15 dB respectively. And a 50 nm gain flattened width was successfully obtained by using a chirp fiber Bragg grating (CFBG) gain flattened filter with gain ripple of 0.6 dB. The C band DFRA has been applied to CDMA wireless communication system successfully.

  16. Cost optimal allocation of amplifiers and DCMs in WDM ring networks.

    Science.gov (United States)

    Minagar, Amir; Premaratne, Malin; Tran, An V

    2006-10-30

    Designing metropolitan wavelength division multiplexing (WDM) ring networks with minimum deployment cost is a demanding issue in Telecommunication Network planning . We have already presented amplifier placement methods to minimize the number of amplifiers in WDM rings for the case all amplifiers follow a unique gain model. In this paper, we take into account different types of amplifiers with predefined fixed characteristics and costs. We also formulate fiber dispersion limitations on the ring design, and present two efficient methods for placing amplifiers and Dispersion Compensation Modules (DCMs) in WDM rings to minimize the total deployment cost of the system. The first method deals with both linear and nonlinear equations and uses a mixed integer nonlinear programming (MINLP) solver where the second method applies the linear approximation of nonlinear constraints, and uses a mixed integer linear programming (MILP) solver to minimize the total cost of the system. We carry out Simulation experiments to confirm the applicability of the methods and compare the results for various network configurations.

  17. Analytical and numerical solutions to the amplifier with incoherent pulse temporal overlap

    Science.gov (United States)

    Li, M.; Zhang, X. M.; Wang, Z. G.; Cui, X. D.; Yan, X. W.; Jiang, X. Y.; Zheng, J. G.; Wang, W.; Li, Mingzhong

    2017-01-01

    Serious pulse temporal overlap in amplifiers would result in the decrease of energy extraction efficiency and the increase of pulse-shape distortion (PSD). Precisely predicting pulse temporal overlap is of significance to an effective amplifier design. In this work, the analytical expressions with complete pulse overlap are derived and a numerical method is proposed to solve the case with partial temporal overlap for a double-pass Nd:YAG amplifier. Our studies, in which pulse temporal overlap is taken into account, can precisely predict the output energy and temporal shape, compared to the results from Hirano and other experiments. In addition, our numerical routes could provide the applicable range of analytical solutions to conventional Frantz-Nodvik equations in the case of pulse overlap, further extending the applicability and reducing computational costs. For given conditions, energy reduction and PSD are mainly determined by the overlap degree. For step-shaped pulse, we demonstrate that avoiding overlap in the peak pulse and allowing overlap in the foot pulse have small impacts on the energy extraction and PSD, which extends the range of duration of the pulse for a designed amplifier. Our investigations might provide an efficient way to carefully design a pulsed amplifier with controllable temporal overlap.

  18. Amplifying Phenomenal Information Toward a Fundamental Theory of Consciousness

    CERN Document Server

    Gabora, L

    1999-01-01

    Since an organism eats other living things to survive, it must behave as if it values its own subjective experience more than that of the entities it consumes. Thus assessments about consciousness are inherently warped. This lends credibility to Chalmers' double aspect theory of information, and suggests that the degree of consciousness is a function of the degree to which information is locally amplified. Autocatalytic closure may induce a phase transition in degree of amplification by trapping and integrating information. The effect may be magnified in humans through a second level of closure: distributed memories (attractors) are woven into a conceptual web through the emergence of abstractions (lower-dimensional attractors). Human consciousness is viewed as a temporally self-similar hyperstructure or sequence of phase relations which evolve and are evolved by this conceptual web. The final stages in the proposed transformation from proto-conscious to human conscious involve reflection, focusing, resonance...

  19. Study of silicon photomultipliers fast amplifier and thermoregulation

    Energy Technology Data Exchange (ETDEWEB)

    D' antone, I. [INFN of Bologna, Viale B.Pichat 4/2, 40127 Bologna (Italy); Fabbri, L.; Foschi, E. [Department of Physics and INFN, Viale B.Pichat 4/2, 40127 Bologna (Italy); Guandalini, C.; Laurenti, G.; Lax, I. [INFN of Bologna, Viale B.Pichat 4/2, 40127 Bologna (Italy); Levi, G.; Quadrani, L.; Sbarra, Ca. [Department of Physics and INFN, Viale B.Pichat 4/2, 40127 Bologna (Italy); Sbarra, Cr., E-mail: cristina.sbarra@bo.infn.i [Department of Physics and INFN, Viale B.Pichat 4/2, 40127 Bologna (Italy); Villa, M.; Zoccoli, A. [Department of Physics and INFN, Viale B.Pichat 4/2, 40127 Bologna (Italy); Zuffa, M. [INFN of Bologna, Viale B.Pichat 4/2, 40127 Bologna (Italy)

    2011-02-21

    The silicon photomultipliers (SiPM) are adopted in various physical applications, from medical physics to astrophysics, for their advantages in terms of cost and weight with respect to traditional photo detectors. Their low bias voltage supply (about 30 V), hardiness and resistance to magnetic field are ideal characteristics for space application. In the frame of INFN-Irst collaboration, some of them have been developed and produced at FBK (Trento-Italy), and have been characterized in the INFN laboratories of Bologna (DaSiPM2 collaboration). The SiPM can be used in conjunction with fibres and counters in high energy physics experiments. To exploit the SiPM time resolution, a fast amplifier has been studied. The SiPM gain depends critically on temperature and a thermal stabilization is also necessary. The use of a thermoelectric cooler module based on a Peltier cell has been investigated, and the results are shown.

  20. Investigating student understanding of operational-amplifier circuits

    Science.gov (United States)

    Papanikolaou, Christos P.; Tombras, George S.; Van De Bogart, Kevin L.; Stetzer, MacKenzie R.

    2015-12-01

    The research reported in this article represents a systematic, multi-year investigation of student understanding of the behavior of basic operational-amplifier (op-amp) circuits. The participants in this study were undergraduates enrolled in upper-division physics courses on analog electronics at three different institutions, as well as undergraduates in introductory and upper-division electrical engineering courses at one of the institutions. The findings indicate that many students complete these courses without developing a functional understanding of the behavior of op-amp circuits. This article describes the most prevalent conceptual and reasoning difficulties identified (typically after lecture and hands-on laboratory experience) as well as several implications for electronics instruction that have emerged from this investigation.

  1. Discretization analysis of bifurcation based nonlinear amplifiers

    Science.gov (United States)

    Feldkord, Sven; Reit, Marco; Mathis, Wolfgang

    2017-09-01

    Recently, for modeling biological amplification processes, nonlinear amplifiers based on the supercritical Andronov-Hopf bifurcation have been widely analyzed analytically. For technical realizations, digital systems have become the most relevant systems in signal processing applications. The underlying continuous-time systems are transferred to the discrete-time domain using numerical integration methods. Within this contribution, effects on the qualitative behavior of the Andronov-Hopf bifurcation based systems concerning numerical integration methods are analyzed. It is shown exemplarily that explicit Runge-Kutta methods transform the truncated normalform equation of the Andronov-Hopf bifurcation into the normalform equation of the Neimark-Sacker bifurcation. Dependent on the order of the integration method, higher order terms are added during this transformation.A rescaled normalform equation of the Neimark-Sacker bifurcation is introduced that allows a parametric design of a discrete-time system which corresponds to the rescaled Andronov-Hopf system. This system approximates the characteristics of the rescaled Hopf-type amplifier for a large range of parameters. The natural frequency and the peak amplitude are preserved for every set of parameters. The Neimark-Sacker bifurcation based systems avoid large computational effort that would be caused by applying higher order integration methods to the continuous-time normalform equations.

  2. Amplified Fiber-Loop Ringdown Spectroscopy

    Science.gov (United States)

    Litman, Jessica; Barnes, Jack; Loock, Hans-Peter

    2009-06-01

    Many commercial liquid chemical analysis systems, such as high-performance liquid chromatography (HPLC) or capillary electrophoresis consist of a separation followed by optical detection. Besides small volumes and low detection limits, the system should also allow the detection of a large variety of analytes. Existing absorption and fluorescence detectors are often not very sensitive or require labelling. Here, an absorption detector is presented based on cavity ring-down spectroscopy (CRDS) where the optical cavity is made from fibre optic waveguides and the light source is a continuous wave (cw) diode laser. The purpose of this project is to increase the detection of analytes through their overtone absorption in the telecom region at 1300 to 1500 nm. This is done by increasing the ratio of desired loss (extinction caused by the sample), to undesirable loss (due to the waveguides or solvents) through amplification of the ringdown signal using a gain-clamped erbium doped fibre amplifier (EDFA). The amplified cavity has a round-trip time of 750 ns and we achieved a detection limit of at most 250 ppm when measuring acetylene at 1532.83 nm. The application of our method to detection of dissolved analytes or particles in liquids will be discussed.

  3. Backward Raman Amplifier for Laser Wakefield Accelerator

    Science.gov (United States)

    Ludwig, Joshua; Masson-Laborde, Paul-Edouard; Huller, Stefan; Rozmus, Wojciech; Wilks, Scott C.

    2016-10-01

    Particle in cell simulations via SCPIC and theoretical work on Raman amplification and laser wake field acceleration will be presented. Laser energy depletion has been shown to be a limiting factor during wake field acceleration. This work focuses on optimizing parameters for Raman amplification to work in conjunction with wake field acceleration in order in order to sustain an accelerating laser pulse as it generates plasma waves. It has been shown that laser pulses undergo red shifting during wake generation. Our work demonstrates that this red shifting results in a detuning between pump and seed in the backward Raman Amplifier. This detuning limits the amount of energy that can be transferred from the pump to the seed, and places new limits on backward Raman amplification. To overcome this limiting factor, this study makes use of a chirped pump allowing for extended coupling to the accelerating pulse. Three wave coupling model of Raman amplifier with a frequency shift term due to wake field will also be discussed and compared with PIC simulations.

  4. High-frequency graphene voltage amplifier.

    Science.gov (United States)

    Han, Shu-Jen; Jenkins, Keith A; Valdes Garcia, Alberto; Franklin, Aaron D; Bol, Ageeth A; Haensch, Wilfried

    2011-09-14

    While graphene transistors have proven capable of delivering gigahertz-range cutoff frequencies, applying the devices to RF circuits has been largely hindered by the lack of current saturation in the zero band gap graphene. Herein, the first high-frequency voltage amplifier is demonstrated using large-area chemical vapor deposition grown graphene. The graphene field-effect transistor (GFET) has a 6-finger gate design with gate length of 500 nm. The graphene common-source amplifier exhibits ∼5 dB low frequency gain with the 3 dB bandwidth greater than 6 GHz. This first AC voltage gain demonstration of a GFET is attributed to the clear current saturation in the device, which is enabled by an ultrathin gate dielectric (4 nm HfO(2)) of the embedded gate structures. The device also shows extrinsic transconductance of 1.2 mS/μm at 1 V drain bias, the highest for graphene FETs using large-scale graphene reported to date.

  5. Design criteria for ultrafast optical parametric amplifiers

    Science.gov (United States)

    Manzoni, C.; Cerullo, G.

    2016-10-01

    Optical parametric amplifiers (OPAs) exploit second-order nonlinearity to transfer energy from a fixed frequency pump pulse to a variable frequency signal pulse, and represent an easy way of tuning over a broad range the frequency of an otherwise fixed femtosecond laser system. OPAs can also act as broadband amplifiers, transferring energy from a narrowband pump to a broadband signal and thus considerably shortening the duration of the pump pulse. Due to these unique properties, OPAs are nowadays ubiquitous in ultrafast laser laboratories, and are employed by many users, such as solid state physicists, atomic/molecular physicists, chemists and biologists, who are not experts in ultrafast optics. This tutorial paper aims at providing the non-specialist reader with a self-consistent guide to the physical foundations of OPAs, deriving the main equations describing their performance and discussing how they can be used to understand their most important working parameters (frequency tunability, bandwidth, pulse energy/repetition rate scalability, control over the carrier-envelope phase of the generated pulses). Based on this analysis, we derive practical design criteria for OPAs, showing how their performance depends on the type of the nonlinear interaction (crystal type, phase-matching configuration, crystal length), on the characteristics of the pump pulse (frequency, duration, energy, repetition rate) and on the OPA architecture.

  6. Hot prospect for new gene amplifier

    Energy Technology Data Exchange (ETDEWEB)

    1991-11-29

    Molecular biologist Francis Barany is investigating one of the hottest areas in biotechnology: a gene-amplification technique called ligase chain reaction, or LCR. Already scientists have used LCR to detect the tiny mutation that causes sickle cell anemia and have adapted it to screen for a handful of other genetic diseases simultaneously - in a single test-tube. Some experts, in fact, are predicting that LCR will supplement the polymerase chain reaction (PCR), and in some cases even supplant it. LCR could revolutionize DNA diagnostics just as PCR transformed basic molecular biology following its introduction 6 years ago. With its ease of automation and ability to produce useful quantitative results, LCR could become a major player in the rapidly growing market for DNA diagnostics. LCR, like PCR, uses snippets of nucleic acid, or oligonucleotides, that anneal to a specific, complementary sequence on the target DNA to be amplified. But where PCR uses oligos that bracket the stretch to be amplified, LCR uses pairs of oligos that completely cover the target sequence.

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

    Science.gov (United States)

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

    2014-01-01

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

  8. Power amplifiers in CMOS technology : a contribution to power amplifier theory and techniques

    NARCIS (Netherlands)

    Acar, Mustafa

    2011-01-01

    In order to meet the demands from the market on cheaper, miniaturized mobile communications devices realization of RF power amplifiers(PAs) in the mainstream CMOS technology is essential. In general, CMOS PAs require high supply-voltage to decrease the matching network losses and for high output pow

  9. Tuneable, non-degenerated, nonlinear, parametrically-excited amplifier

    Science.gov (United States)

    Dolev, Amit; Bucher, Izhak

    2016-01-01

    The proposed parametric amplifier scheme can be tuned to amplify a wide range of input frequencies by altering the parametric excitation with no need to physically modify the oscillator. Parametric amplifiers had been studied extensively, although most of the work focused on amplifiers that are parametrically excited at a frequency twice the amplifier's natural frequency. These amplifiers are confined to amplifying predetermined frequencies. The proposed parametric amplifier's bandwidth is indeed tuneable to nearly any input frequency, not bound to be an integer multiple of a natural frequency. In order to tune the stiffness and induce a variable frequency parametric excitation, a digitally controlled electromechanical element must be incorporated in the realization. We introduce a novel parametric amplifier with nonlinearity, Duffing type hardening, that bounds the otherwise unlimited amplitude. Moreover, we present a multi degree of freedom system in which a utilization of the proposed method enables the projection of low frequency vector forces on any eigenvector and corresponding natural frequency of the system, and thus to transform external excitations to a frequency band where signal levels are considerably higher. Using the method of multiple scales, analytical expressions for the responses have been retrieved and verified numerically. Parametric studies of the amplifiers' gain, sensitivities and spatial projection of the excitation on the system eigenvectors were carried out analytically. The results demonstrate the advantage of the proposed approach over existing schemes. Practical applications envisaged for the proposed method will be outlined.

  10. Investigation of Neganov-Luke amplified cryogenic light-detectors for CRESST and EURECA

    Energy Technology Data Exchange (ETDEWEB)

    Ertl, Andreas; Guetlein, Achim; Lanfranchi, Jean-Come; Muenster, Andrea; Potzel, Walter; Roth, Sabine; Simon, Daniel; Scholl, Stephan; Sivers, Moritz von; Strauss, Raimund; Wawoczny, Stephan; Willers, Michael; Wuestrich, Marc; Zoeller, Andreas [Technische Universitaet Muenchen, Physik Department E15, Garching (Germany)

    2013-07-01

    Experiments for the direct detection of dark matter which employ the phonon-light technique like CRESST and the planned experiment EURECA rely heavily on the separation of the different nuclear-recoil bands at low energies for their background suppression. The CRESST experiment uses scintillating CaWO{sub 4} crystals as a target in the search for coherent WIMP-nucleon scattering. In the case of electron recoils, about 1% of the energy deposited in a CaWO{sub 4} crystal is detected as scintillation light in a separate cryogenic light-detector. For nuclear recoils the scintillation light is further quenched which motivates the need for very sensitive light-detectors. Neganov-Luke amplified cryogenic light-detectors offer a promising way to increase the sensitivity of cryogenic light-detectors by drifting photon induced electrons and holes in an applied electric field and thus amplifying the resulting phonon signal.

  11. Gender Differences on the Use of Amplifiers in Academic Writings

    Institute of Scientific and Technical Information of China (English)

    申利芬

    2012-01-01

      This study aims to investigate the use of amplifiers in term of gender and disciplinary groups in academic research arti⁃cles, which is based on the British Academic Written English Corpus (BAWE).18 amplifiers were examined across two dimen⁃sions:gender and disciplinary groups. The results show amplifiers are more common in males’ academic writings than in those of females in general, amplifiers are used more often in AH discipline. However, not all amplifiers show significant gender differ⁃ences between men and women. Six words show a significant difference between male and female writers:pretty, by far, perfect⁃ly, quite, a great deal, totally, which are used more often by males. However, the interesting is in LS discipline, most amplifiers are used more often by female than male writers and males tend to use by far more frequently than females.

  12. Realization of OFCC based Transimpedance Mode Instrumentation Amplifier

    Directory of Open Access Journals (Sweden)

    Neeta Pandey

    2016-01-01

    Full Text Available The paper presents an instrumentation amplifier suitable for amplifying the current source transducer signals. It provides a voltage output. It has a high gain, common mode rejection ratio and gain independent bandwidth. It uses three Operational Floating Current Conveyors (OFCCs and four resistors. The effect of nonidealities of OFCC on performance of proposed transimpedance instrumentation amplifier (TIA is also analyzed. The proposal has been verified through SPICE simulations using CMOS based schematicThe paper presents an instrumentation amplifier suitable for amplifying the current source transducer signals. It provides a voltage output. It has a high gain, common mode rejection ratio and gain independent bandwidth. It uses three operational floating current conveyors (OFCCs and four resistors. The effect of nonidealities of OFCC on performance of proposed transimpedance instrumentation amplifier (TIA is also analyzed. The proposal has been verified through SPICE simulations using CMOS based schematic.

  13. Layered-nanomaterial-amplified chemiluminescence systems and their analytical applications.

    Science.gov (United States)

    Zhong, Jinpan; Yuan, Zhiqin; Lu, Chao

    2016-12-01

    Layered nanomaterial has become a popular hierarchical material for amplifying chemiluminescence (CL) in recent years, mainly because of its ease of preparation and modification, large specific surface area, and high catalytic activity. In this review, we mainly discuss layered-nanomaterial-amplified CL systems based on graphene and its derivatives, layered double hydroxides, and clay. Detection mechanisms and strategies of layered-nanomaterial-amplified CL systems are provided to show the basic concepts for designing sensitive and selective sensing systems. Strategies for expanding the applications of layered-nanomaterial-amplified CL systems by combination with surfactants, quantum dots, organic dyes, and nanoparticles are introduced for the analysis of various analytes in real samples. The challenges and future trends of layered-nanomaterial-amplified CL systems are discussed at the end of the review. Graphical Abstract Schematic illustration of layered nanomaterial amplified chemiluminescence.

  14. Analysis of monolithic integrated master oscillator power amplifiers

    Science.gov (United States)

    Mehuys, David; Welch, David F.; Waarts, Robert G.; Parke, Ross; Hardy, Amos; Streifer, William

    1991-07-01

    An analysis of a novel, monolithic integrated master oscillator power amplifier (M-MOPA) is presented. The M-MOPA consists of a DBR master oscillator which injects power into a linear chain of amplifiers and detuned second-order grating output couplers. The analysis self-consistently includes amplified spontaneous emission buildup and residual reflections throughout the amplifier stages. It predicts that output powers in excess of 1 W can be expected from a single-lateral-mode waveguide multistage amplifier less than 1 cm in length, injected with less than 15 mW of input power. In addition to the signal gain of more than 25 dB, the signal-to-noise ratio at 1-W output exceeds 15 dB. Because of the small reflections associated with the grating output couplers, and gain saturation by the injected signal, the amplifier self-oscillation threshold is suppressed to current densities above 15 kA/sq cm.

  15. Multiple Differential-Amplifier MMICs Embedded in Waveguides

    Science.gov (United States)

    Kangaslahti, Pekka; Schlecht, Erich

    2010-01-01

    Compact amplifier assemblies of a type now being developed for operation at frequencies of hundreds of gigahertz comprise multiple amplifier units in parallel arrangements to increase power and/or cascade arrangements to increase gains. Each amplifier unit is a monolithic microwave integrated circuit (MMIC) implementation of a pair of amplifiers in differential (in contradistinction to single-ended) configuration. Heretofore, in cascading amplifiers to increase gain, it has been common practice to interconnect the amplifiers by use of wires and/or thin films on substrates. This practice has not yielded satisfactory results at frequencies greater than 200 Hz, in each case, for either or both of two reasons: Wire bonds introduce large discontinuities. Because the interconnections are typically tens of wavelengths long, any impedance mismatches give rise to ripples in the gain-vs.-frequency response, which degrade the performance of the cascade.

  16. ANALYSIS OF INTERNALLY GENERATED NOISE OF BIOELECTRIC AMPLIFIERS

    Institute of Scientific and Technical Information of China (English)

    Mashhour Mustafa; Bani Amer

    2003-01-01

    This paper deals with internally generated noise of bioelectric amplifiers that are usually used for processing of bioelectric events. The main purpose of this paper is to present a procedure for analysis of the effects of internal noise generated by the active circuits and to evaluate the output noise of the author's new designed bioelectric amplifier that caused by internal effects to the amplifier circuit itself in order to compare it with the noise generated by conventional amplifiers. The obtained analysis results of internally generated noise showed that the total output noise of bioelectric active circuits does not increase when some of their resistors have a larger value. This behavior is caused by the different transfer functions for the signal and the respective noise sources associated with these resistors. Moreover, the new designed bioelectric amplifier has an output noise less than that for conventional amplifiers. The obtained analysis results were also experimentally verified and the final conclusions were drawn.

  17. Gain Characteristics of Fiber Optical Parametric Amplifier

    Institute of Scientific and Technical Information of China (English)

    高明义; 姜淳; 胡卫生

    2004-01-01

    The theory model of fiber optical parametric amplifier (FOPA) was introduced, which is based on optical nonlinear effect. And then numerical simulation was done to analyze and discuss the gain spectral characteristics of one-pump and two-pump FOPA. The results show that for one-pump FOPA, when pump wavelength is near to fiber zero-dispersion wavelength(ZDW), the gain flatness is better, and with the increase of the pump power, fiber length and its nonlinear coefficient, the gain value will increase while the gain bandwidth will become narrow. For two-pump FOPA, when the pump central wavelength is near to fiber ZDW, the gain flatness is better. Moreover, by decreasing the space of two pumps wavelength, the gain flatness can be improved. Finally, some problems existing in FOPA were addressed.

  18. Current feedback operational amplifiers and their applications

    CERN Document Server

    Senani, Raj; Singh, A K; Singh, V K

    2013-01-01

    This book describes a variety of current feedback operational amplifier (CFOA) architectures and their applications in analog signal processing/generation. Coverage includes a comprehensive survey of commercially available, off-the-shelf integrated circuit CFOAs, as well as recent advances made on the design of CFOAs, including design innovations for bipolar and CMOS CFOAs.  This book serves as a single-source reference to the topic, as well as a catalog of over 200 application circuits which would be useful not only for students, educators and researchers in apprising them about the recent developments in the area but would also serve as a comprehensive repertoire of useful circuits for practicing engineers who might be interested in choosing an appropriate CFOA-based topology for use in a given application.

  19. Stochastic phenomena in a fiber Raman amplifier

    CERN Document Server

    Kalashnikov, Vladimir; Ania-Castanón, Juan Diego; Jacobsen, Gunnar; Popov, Sergei

    2016-01-01

    The interplay of such cornerstones of modern nonlinear fiber optics as a nonlinearity, stochasticity and polarization leads to variety of the noise induced instabilities including polarization attraction and escape phenomena harnessing of which is a key to unlocking the fiber optic systems specifications required in high resolution spectroscopy, metrology, biomedicine and telecommunications. Here, by using direct stochastic modeling, the mapping of interplay of the Raman scattering-based nonlinearity, the random birefringence of a fiber, and the pump-to-signal intensity noise transfer has been done in terms of the fiber Raman amplifier parameters, namely polarization mode dispersion, the relative intensity noise of the pump laser, fiber length, and the signal power. The obtained results reveal conditions for emergence of the random birefringence-induced resonance-like enhancement of the gain fluctuations (stochastic anti-resonance) accompanied by pulse broadening and rare events in the form of low power outpu...

  20. Quantum repeaters based on heralded qubit amplifiers

    CERN Document Server

    Minář, Jiří; Sangouard, Nicolas

    2011-01-01

    We present a quantum repeater scheme based on the recently proposed qubit amplifier [N. Gisin, S. Pironio and N. Sangouard, Phys. Rev. Lett. 105, 070501 (2010)]. It relies on a on-demand entangled-photon pair source which uses on-demand single-photon sources, linear optical elements and atomic ensembles. Interestingly, the imperfections affecting the states created from this source, caused e.g. by detectors with non-unit efficiencies, are systematically purified from an entanglement swapping operation based on a two-photon detection. This allows the distribution of entanglement over very long distances with a high fidelity, i.e. without vacuum components and multiphoton errors. Therefore, the resulting quantum repeater architecture does not necessitate final postselections and thus achieves high entanglement distribution rates. This also provides unique opportunities for device-independent quantum key distribution over long distances with linear optics and atomic ensembles.

  1. Low-noise amplifiers for satellite communications

    Science.gov (United States)

    Whelehan, J.

    1984-02-01

    It is pointed out that over the past several years significant advances have been made in the overall capability of both microwave and mm-wave receivers. This is particularly apparent in the telecom market. Integral parts of advanced receiver technology are low-noise receivers. The advances currently being achieved in low-noise technology are partly based on developments in GaAs semiconductor technology. The development of high-cutoff-frequency beam lead mixer diodes has led to the development of mm-wave low-noise mixers with excellent low-noise capability. The advanced techniques are now being employed in field-deployable systems. Low noise is an important factor in satellite communications applications. Attention is given to C-band fixed satellite service, C-band parametric amplifiers, C-band FET, and X band, the Ku band, and the 30/20 GHz band.

  2. Numerical Analysis of Modal Instability Onset in Fiber Amplifiers

    Science.gov (United States)

    2014-03-11

    Evolution of the logarithmic frequency spectrum of the off-center optical intensity probe along the length of the co-pumped amplifier for the case of...Evolution of the logarithmic frequency spectrum of the off-center optical intensity probe along the length of the counter-pumped amplifier for the...ABSTRACT 16. SECURITY CLASSIFICATION OF: Numerical analysis of the onset of modal instability in fiber amplifiers is presented. Specifically calculations

  3. InP Heterojunction Bipolar Transistor Amplifiers to 255 GHz

    Science.gov (United States)

    Radisic, Vesna; Sawdai, Donald; Scott, Dennis; Deal, William; Dang, Linh; Li, Danny; Cavus, Abdullah; To, Richard; Lai, Richard

    2009-01-01

    Two single-stage InP heterojunction bipolar transistor (HBT) amplifiers operate at 184 and 255 GHz, using Northrop Grumman Corporation s InP HBT MMIC (monolithic microwave integrated circuit) technology. At the time of this reporting, these are reported to be the highest HBT amplifiers ever created. The purpose of the amplifier design is to evaluate the technology capability for high-frequency designs and verify the model for future development work.

  4. Modeling and design techniques for RF power amplifiers

    CERN Document Server

    Raghavan, Arvind; Laskar, Joy

    2008-01-01

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

  5. GaN-based Power amplifiers for microwave applications

    Directory of Open Access Journals (Sweden)

    Jorge Julián Moreno-Rubio

    2016-01-01

    Full Text Available This paper presents a discussion about the design strategies of different kind of power amplifiers for RF/Microwave appli- cations, such as the tuned load power amplifier, class F, class F-1 and Doherty. Furthermore, it is shown the continuous wave characterization of the amplifiers above mentioned. A comparison between the obtained results, in terms of gain, efficiency and output power is presented.

  6. Development of a Precision Amplifier for the Detector

    CERN Document Server

    Park, Ki-Hyeon; Hong, Suk-Mo; Jeong, Seong-Hun; Jung, Young-Gyu; Kang, Bong-Koo; Lee, Hee-Seock; Wha Chung, Chin; Woo Lee, Wol

    2005-01-01

    A high gain trans-resistance amplfier has been developed for measuring the intensity of synchrotron radiation at Pohang Light Source(PLS). This amplifier built with discrete elements and operational amplifiers.It had the capability of measuring range from 1pA to 1 uA with good linearity. A microprocessor was also installed to interface the amplifier with the computer, and controlled the other sub-circuits. The various characteristics of amplifier such as linearity, sensitivity,stability, etc. have been investigated, and its experimental results carried out at the beam line are presented in this paper.

  7. Modeling a Common-Source Amplifier Using a Ferroelectric Transistor

    Science.gov (United States)

    Sayyah, Rana; Hunt, Mitchell; MacLeond, Todd C.; Ho, Fat D.

    2010-01-01

    This paper presents a mathematical model characterizing the behavior of a common-source amplifier using a FeFET. The model is based on empirical data and incorporates several variables that affect the output, including frequency, load resistance, and gate-to-source voltage. Since the common-source amplifier is the most widely used amplifier in MOS technology, understanding and modeling the behavior of the FeFET-based common-source amplifier will help in the integration of FeFETs into many circuits.

  8. Nylon Sleeve for Cavity Amplifier Holds Tuning Despite Heat

    Science.gov (United States)

    Derr, Lloyd

    1964-01-01

    The problem: Detuning of cavity amplifiers with change in temperature. This results in deterioration of the performance of the amplifier at its design frequency. In cavity amplifiers and filters it is desirable that constant performance be maintained regardless of thermal changes. These changes often cause an "off resonance shift" in a cavity filter and a deterioration of performance in a cavity amplifier. The solution: Mount the tuning probe in a nylon sleeve. Thermal expansion and contraction of the nylon nullifies unwanted capacitive and inductive changes in the resonant elements.

  9. Combination ring cavity and backward Raman waveguide amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Kurnit, N.A.

    1981-03-13

    A combination regenerative ring and backward Raman waveguide amplifier and a combination regenerative ring oscillator and backward Raman waveguide amplifier which produce Raman amplification, pulse compression, and efficient energy extraction from the CO/sub 2/ laser pump signal for conversion into a Stokes radiation signal. The ring cavity configuration allows the CO/sub 2/ laser pump signal and Stokes signal to copropagate through the Raman waveguide amplifier. The backward Raman waveguide amplifier configuration extracts a major portion of the remaining energy from the CO/sub 2/ laser pump signal for conversion to Stokes radiation.

  10. Dual Band High Efficiency Power Amplifier Based on CRLH Lines

    Directory of Open Access Journals (Sweden)

    D. Segovia-Vargas

    2009-12-01

    Full Text Available In this paper we propose the use of Composite Right/Left Hand (CRLH and Extended Composite Right/Left Hand (ECRLH transmission lines for the design of dual band high efficiency power amplifiers working in CE class. The harmonic termination can be synthesized using the meta-lines is particularly suitable for CE class amplifiers, which have a termination not as sensitive to the third harmonic as F class amplifier. This paper presents the design procedure and the design equations. The nonlinear phase response of a CRLH and ECRLH transmission line has been utilized to design arbitrary dual-band amplifiers.

  11. Controlling the dynamic range of a Josephson parametric amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Eichler, Christopher; Wallraff, Andreas [ETH Zuerich, Department of Physics, Zuerich (Switzerland)

    2014-12-01

    One of the central challenges in the development of parametric amplifiers is the control of the dynamic range relative to its gain and bandwidth, which typically limits quantum limited amplification to signals which contain only a few photons per inverse bandwidth. Here, we discuss the control of the dynamic range of Josephson parametric amplifiers by using Josephson junction arrays. We discuss gain, bandwidth, noise, and dynamic range properties of both a transmission line and a lumped element based parametric amplifier. Based on these investigations we derive useful design criteria, which may find broad application in the development of practical parametric amplifiers. (orig.)

  12. Pulse-distortion in a quantum-dot optical amplifier

    DEFF Research Database (Denmark)

    Romstad, Francis Pascal; Borri, Paola; Mørk, Jesper;

    2000-01-01

    Distortion of a -150fs optical pulse after propagation through an InAs/InGaAs quantum-dot optical amplifier is measured for different input energies an bias currents. Pulse distortion is observed and compared with results on a bulk amplifier.......Distortion of a -150fs optical pulse after propagation through an InAs/InGaAs quantum-dot optical amplifier is measured for different input energies an bias currents. Pulse distortion is observed and compared with results on a bulk amplifier....

  13. Parametric Amplifiers for Microwave Kinectic Inductance Detector (MKID) Readout Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Find numerical solutions to the non-linear partial differential equations describing our amplifier transmission lines. Optimize periodic choke structure to block...

  14. Switching-mode Audio Power Amplifiers with Direct Energy Conversion

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper presents a new class of switching-mode audio power amplifiers, which are capable of direct energy conversion from the AC mains to the audio output. They represent an ultimate integration of a switching-mode power supply and a Class D audio power amplifier, where the intermediate DC bus...... has been replaced with a high frequency AC link. When compared to the conventional Class D amplifiers with a separate DC power supply, the proposed single conversion stage amplifier provides simple and compact solution with better efficiency and higher level of integration, leading to reduced...

  15. Modeling and analysis of overmodulation in erbium-doped fiber amplifiers including amplified spontaneous emission

    Science.gov (United States)

    Sharma, Reena; Raghuwanshi, Sanjeev Kumar

    2017-02-01

    Line surveillance and management information in erbium-doped fiber amplifiers (EDFAs) can be broadcast by modulating the amplitude of the low-frequency lightwave information signal, the process termed as overmodulation in the literature. This paper presents systematic solutions for the overmodulated pump and information signal transfer functions for EDFA. It includes amplified spontaneous emission (ASE) that has an impact on outcomes in the high-gain system. To the extent of our belief, the methodical model simulated with the current approach leads to a distinct perspective of an outcome in the respective field. The test bed described here is realistic. It specifically represents the overmodulation behavior in an EDFA under the influence of ASE.

  16. Optimal Relay Power Allocation for Amplify-and-Forward Relay Networks with Non-linear Power Amplifiers

    OpenAIRE

    Zhang, Chao; Ren, Pinyi; Peng, Jingbo; Wei, Guo; Du, Qinghe; Wang, Yichen

    2011-01-01

    In this paper, we propose an optimal relay power allocation of an Amplify-and-Forward relay networks with non-linear power amplifiers. Based on Bussgang Linearization Theory, we depict the non-linear amplifying process into a linear system, which lets analyzing system performance easier. To obtain spatial diversity, we design a complete practical framework of a non-linear distortion aware receiver. Consider a total relay power constraint, we propose an optimal power allocation scheme to maxim...

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

    OpenAIRE

    Hassan, Muhammad

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-21

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

  19. Theory of parametrically amplified electron-phonon superconductivity

    Science.gov (United States)

    Babadi, Mehrtash; Knap, Michael; Martin, Ivar; Refael, Gil; Demler, Eugene

    2017-07-01

    Ultrafast optical manipulation of ordered phases in strongly correlated materials is a topic of significant theoretical, experimental, and technological interest. Inspired by a recent experiment on light-induced superconductivity in fullerenes [M. Mitrano et al., Nature (London) 530, 461 (2016), 10.1038/nature16522], we develop a comprehensive theory of light-induced superconductivity in driven electron-phonon systems with lattice nonlinearities. In analogy with the operation of parametric amplifiers, we show how the interplay between the external drive and lattice nonlinearities lead to significantly enhanced effective electron-phonon couplings. We provide a detailed and unbiased study of the nonequilibrium dynamics of the driven system using the real-time Green's function technique. To this end, we develop a Floquet generalization of the Migdal-Eliashberg theory and derive a numerically tractable set of quantum Floquet-Boltzmann kinetic equations for the coupled electron-phonon system. We study the role of parametric phonon generation and electronic heating in destroying the transient superconducting state. Finally, we predict the transient formation of electronic Floquet bands in time- and angle-resolved photoemission spectroscopy experiments as a consequence of the proposed mechanism.

  20. Face-to-face: Perceived personal relevance amplifies face processing.

    Science.gov (United States)

    Bublatzky, Florian; Pittig, Andre; Schupp, Harald T; Alpers, Georg W

    2017-05-01

    The human face conveys emotional and social information, but it is not well understood how these two aspects influence face perception. In order to model a group situation, two faces displaying happy, neutral or angry expressions were presented. Importantly, faces were either facing the observer, or they were presented in profile view directed towards, or looking away from each other. In Experiment 1 (n = 64), face pairs were rated regarding perceived relevance, wish-to-interact, and displayed interactivity, as well as valence and arousal. All variables revealed main effects of facial expression (emotional > neutral), face orientation (facing observer > towards > away) and interactions showed that evaluation of emotional faces strongly varies with their orientation. Experiment 2 (n = 33) examined the temporal dynamics of perceptual-attentional processing of these face constellations with event-related potentials. Processing of emotional and neutral faces differed significantly in N170 amplitudes, early posterior negativity (EPN), and sustained positive potentials. Importantly, selective emotional face processing varied as a function of face orientation, indicating early emotion-specific (N170, EPN) and late threat-specific effects (LPP, sustained positivity). Taken together, perceived personal relevance to the observer-conveyed by facial expression and face direction-amplifies emotional face processing within triadic group situations. © The Author (2017). Published by Oxford University Press.

  1. Theory of parametrically amplified electron-phonon superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Babadi, Mehrtash; Knap, Michael; Martin, Ivar; Refael, Gil; Demler, Eugene

    2017-07-01

    Ultrafast optical manipulation of ordered phases in strongly correlated materials is a topic of significant theoretical, experimental, and technological interest. Inspired by a recent experiment on light-induced superconductivity in fullerenes [M. Mitrano et al., Nature (London) 530, 461 (2016)], we develop a comprehensive theory of light-induced superconductivity in driven electron-phonon systemswith lattice nonlinearities. In analogy with the operation of parametric amplifiers, we show how the interplay between the external drive and lattice nonlinearities lead to significantly enhanced effective electron-phonon couplings. We provide a detailed and unbiased study of the nonequilibrium dynamics of the driven system using the real-time Green's function technique. To this end, we develop a Floquet generalization of the Migdal-Eliashberg theory and derive a numerically tractable set of quantum Floquet-Boltzmann kinetic equations for the coupled electron-phonon system. We study the role of parametric phonon generation and electronic heating in destroying the transient superconducting state. Finally, we predict the transient formation of electronic Floquet bands in time-and angle-resolved photoemission spectroscopy experiments as a consequence of the proposed mechanism.

  2. The eight-channel ASIC bipolar transresistance amplifier D0M AMPL-8.3

    CERN Document Server

    Alexeev, G D; Dvornikov, O V; Khokhlov, A I; Mikhailov, V A; Odnokloubov, I A; Tokmenin, V V

    2001-01-01

    The eight-channel ASIC low-noise bipolar transresistance amplifier D0M Ampl-8.3 has been designed on the basis of BJT-JFET technology for gaseous wire detectors used in high-energy physics experiments. The amplifier has differential gain 130 mV/mu A at 1 k OMEGA, input noise 35 and 60 nA r.m.s. at 0 and 60 pF input capacitance, respectively, leading/trailing edge 7 ns, input resistance approx 50 OMEGA, crosstalks -47 dB, dissipated power 160 triple bond 640 mW/chip for +-3 triple bond 5 V supply. The Ampl-8.3 has been accepted for upgrading the Forward Angle Muon System of the D0 experiment (Fermilab, Batavia, USA), the total number of channels is about 50,000.

  3. The Costs of Suppressing Negative Emotions and Amplifying Positive Emotions During Parental Caregiving.

    Science.gov (United States)

    Le, Bonnie M; Impett, Emily A

    2016-03-01

    How do parents feel when they regulate their emotional expressions in ways that are incongruent with their genuine feelings? In an experimental study, parents reported experiencing lower authenticity, emotional well-being, relationship quality, and responsiveness to their children's needs when they recalled caregiving experiences in which they suppressed negative emotions and amplified positive emotions, relative to a control condition. In a 10-day daily experience study, parents tended to use both regulation strategies simultaneously. In addition, assessing their unique effects indicated that positive emotion amplification, but not negative emotion suppression, had an indirect effect on parental outcomes via authenticity, with negative emotion suppression no longer being costly. This indirect effect was dampened when accounting for care difficulty. In both studies, effects were independent of a child's mood. The current results suggest that parents' attempts to suppress negative and amplify positive emotions during child care can detract from their well-being and high-quality parent-child bonds.

  4. Phase Sensitive Amplifier Based on Ultrashort Pump Pulses

    CERN Document Server

    Gershikov, Alexander

    2016-01-01

    We demonstrate a narrow band phase sensitive amplifier in the pump degenerate configuration which employs ps pump pulses. Control of the amplifier bandwidth is achieved via changes of the pump spectral width. A phase sensitive gain between -6 and 6 decibels, with an overall system gain of 28dB was demonstrated.

  5. External Peltier Cooler For Low-Noise Amplifier

    Science.gov (United States)

    Soper, Terry A.

    1990-01-01

    Inexpensive Peltier-effect cooling module made of few commercially available parts used to reduce thermal noise in microwave amplifier. Retrofitted to almost any microwave low-noise amplifier or receiver preamplifier used in communication, telemetry, or radar. Includes copper or aluminum cold plate held tightly against unit to be cooled by strap-type worm-gear clamps.

  6. Slow Light at High Frequencies in an Amplifying Semiconductor Waveguide

    DEFF Research Database (Denmark)

    Öhman, Filip; Yvind, Kresten; Mørk, Jesper

    2006-01-01

    We demonstrate slow-down of a modulated light signal in a semiconductor waveguide. Concatenated amplifying and absorbing sections simultaneously achieve both amplification and a controllable time delay at 15 GHz.......We demonstrate slow-down of a modulated light signal in a semiconductor waveguide. Concatenated amplifying and absorbing sections simultaneously achieve both amplification and a controllable time delay at 15 GHz....

  7. PHEMT Distributed Power Amplifier Adopting Broadband Impedance Transformer

    DEFF Research Database (Denmark)

    Narendra, K.; Limiti, E.; Paoloni, C.

    2013-01-01

    A non-uniform drain line distributed power amplifier (DPA) employing a broadband impedance transformer is presented. The DPA is based on GaAs PHEMT technology. The impedance transformer employs asymmetric coupled lines and transforms a low output impedance of the amplifier to a standard 50 Ω...

  8. Influence of higher order modes on angled-facet amplifiers

    DEFF Research Database (Denmark)

    Wang, Z.; Mikkelsen, B.; Stubkjær, Kristian

    1991-01-01

    The influence of the first-order mode on the residual reflectivity of angled-facet amplifiers is analyzed. For a 7 degrees angled-facet ridge waveguide amplifier with a single-layer antireflective (AR) coating, a gain ripple lower than 1-dB at 25-dB gain can be obtained independent...... by increasing the facet angles to 10 degrees...

  9. Energy Efficient and Compact RF High-Power Amplifiers

    NARCIS (Netherlands)

    Calvillo Cortés, D.A.

    2014-01-01

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

  10. Switching-mode Audio Power Amplifiers with Direct Energy Conversion

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper presents a new class of switching-mode audio power amplifiers, which are capable of direct energy conversion from the AC mains to the audio output. They represent an ultimate integration of a switching-mode power supply and a Class D audio power amplifier, where the intermediate DC bus...

  11. An RF Power Amplifier in a Digital CMOS Process

    DEFF Research Database (Denmark)

    Nielsen, Per Asbeck; Fallesen, Carsten

    2002-01-01

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

  12. 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....

  13. The Warm, Rich Sound of Valve Guitar Amplifiers

    Science.gov (United States)

    Keeports, David

    2017-01-01

    Practical solid state diodes and transistors have made glass valve technology nearly obsolete. Nevertheless, valves survive largely because electric guitar players much prefer the sound of valve amplifiers to the sound of transistor amplifiers. This paper discusses the introductory-level physics behind that preference. Overdriving an amplifier…

  14. Amplifying Islam : Pluralism, Secularism, and Religious Sounds in The Netherlands

    NARCIS (Netherlands)

    Tamimi Arab, P.

    2015-01-01

    This dissertation is an ethnographic study of the amplified azan, the Islamic call to prayer, in the Netherlands, adding a sonic dimension to analyses of the politics of Islamic aesthetics in the western world. Often rejected by opponents as noise pollution, facilitating the amplified azan is an exa

  15. A 300°C Dynamic-Feedback Instrumentation Amplifier

    NARCIS (Netherlands)

    Jong, P.C. de; Meijer, G.C.M.; Roermund, A.H.M. van

    1998-01-01

    A high-temperature instrumentation amplifier that uses dynamic feedback is presented. It realizes dynamic feedback by means of a rotating chain of resistors to compensate for resistor mismatches. An 11x dynamic-feedback instrumentation amplifier has been integrated in a standard junction-isolated 1.

  16. The design of erbium-doped fiber amplifiers

    DEFF Research Database (Denmark)

    Pedersen, Bo; Bjarklev, Anders Overgaard; Povlsen, Jørn Hedegaard

    1991-01-01

    An accurate model for the erbium-doped fiber amplifier is presented. The model is used to design the index profile of the doped fiber, optimizing with regard to efficiency for inline- and preamplifiers as well as for power booster amplifiers. The predicted pump efficiencies (maximum gain to pump...

  17. Design and Analysis of Hybrid CMOS SRAM Sense Amplifier

    Directory of Open Access Journals (Sweden)

    Karishma Bajaj

    2012-03-01

    Full Text Available Sense amplifiers are one of the very important peripheral components of CMOS memories. In a Hybrid Sense amplifier both current and voltage sensing techniques are used which makes it a better selection than a conventional current or voltage sense amplifiers. The hybrid sense amplifier works in three phases-Offset cancellation (200ps, Access phase (500ps and Evaluation phase. The offset cancellation is done simultaneously with word line decoding, so as to speed up the process. The sensing range of the hybrid sense amplifier is improved from 1.18mV to 92mV. Also hybrid sense amplifier consumes very low energy of about 6.84fj. This sense amplifier is analyzed with a column of 512 SRAM cells at 180nm technology node and compared to CMOS conventional voltage sense amplifier. The circuit consumes an average power of 1.57 µW with a negligible offset of 149.3µV.

  18. Ferroelectric Field-Effect Transistor Differential Amplifier Circuit Analysis

    Science.gov (United States)

    Phillips, Thomas A.; MacLeod, Todd C.; Ho, Fat D.

    2008-01-01

    There has been considerable research investigating the Ferroelectric Field-Effect Transistor (FeFET) in memory circuits. However, very little research has been performed in applying the FeFET to analog circuits. This paper investigates the use of FeFETs in a common analog circuit, the differential amplifier. The two input Metal-Oxide-Semiconductor (MOS) transistors in a general MOS differential amplifier circuit are replaced with FeFETs. Resistors are used in place of the other three MOS transistors. The FeFET model used in the analysis has been previously reported and was based on experimental device data. Because of the FeFET hysteresis, the FeFET differential amplifier has four different operating modes depending on whether the FeFETs are positively or negatively polarized. The FeFET differential amplifier operation in the different modes was analyzed by calculating the amplifier voltage transfer and gain characteristics shown in figures 2 through 5. Comparisons were made between the FeFET differential amplifier and the standard MOS differential amplifier. Possible applications and benefits of the FeFET differential amplifier are discussed.

  19. Saturation and noise properties of quantum-dot optical amplifiers

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Mørk, Jesper

    2004-01-01

    Based on extensive numerical calculations, quantum-dot (QD) amplifiers are predicted to offer higher output power and lower noise figure compared to bulk as well as quantum well amplifiers. The underlying physical mechanisms are analyzed in detail, leading to the identification of a few key...

  20. Subjective test of class D amplifiers without output filter

    DEFF Research Database (Denmark)

    Agerkvist, Finn T.; Fenger, Lars M.

    2004-01-01

    This paper presents the results of subjective listening tests designed to determine whether the output filter on class D amplifiers used in active loudspeakers can be omitted without audible errors occurring. The frequency range of the amplifiers was limited to 0-3 kHz corresponding to a woofer...

  1. A Power Efficient Audio Amplifier Combining Switching and Linear Techniques

    NARCIS (Netherlands)

    van der Zee, Ronan A.R.; van Tuijl, Adrianus Johannes Maria

    1998-01-01

    Integrated Class D audio amplifiers are very power efficient, but require an external filter which prevents further integration. Also due to this filter, large feedback factors are hard to realise, so that the load influences the distortion- and transfer characteristics. The amplifier presented in

  2. Coherent Beam Combination of Two Polarization Maintaining Ytterbium Fibre Amplifiers

    Institute of Scientific and Technical Information of China (English)

    HOU Jing; XIAO Rui; JIANG Zong-Fu; CHENG Xiang-Ai; SHU Bai-Hong; CHEN Jin-Bao; LIU Ze-Jin

    2005-01-01

    @@ We investigate coherent beam combination of fibre laser beams by phase locking. Phase noise of a polarization maintaining ytterbium fibre amplifier is inspected with a fibre interferometer. In a feed back control loop, two fibre polarization maintaining ytterbium amplifiers are phase locked and coherent combined when the phase noise is properly controlled by a LiNO3 phase modulator.

  3. A Power Efficient Audio Amplifier Combining Switching and Linear Techniques

    NARCIS (Netherlands)

    van der Zee, Ronan A.R.; van Tuijl, Adrianus Johannes Maria

    1998-01-01

    Integrated Class D audio amplifiers are very power efficient, but require an external filter which prevents further integration. Also due to this filter, large feedback factors are hard to realise, so that the load influences the distortion- and transfer characteristics. The amplifier presented in t

  4. A 24 channel acoustic/vibration test power amplifier

    Science.gov (United States)

    Barlett, F. R.

    1978-01-01

    In the present paper, the advantages and drawbacks of a multichannel amplifier operating in a vibration or acoustic facility are discussed. The configuration of the facility and the multichannel amplifier proposed is a compromise based on the particular requirements and anticipated work load in a specific case under consideration.

  5. Capacitance Sensing and Software-Realized Lock-in Amplifier for the Electromagnetically Levitated Micro Gyroscope

    Institute of Scientific and Technical Information of China (English)

    HUANG Xiao-gang; CHEN Wen-yuan; LIU Wu; ZHANG Wei-ping; WU Xiao-sheng

    2007-01-01

    In the novel prototype of micro-gyroscope structure, the new configured capacitance sensing scheme for the micro gyroscope was analyzed and the virtual instrument based detection scheme was implemented. The digital lock-in amplifier was employed in the capacitance detection to restrain the noise interference. The capacitance analysis shows that 1 fF capacitance variation corresponds to 0.1 degree of the turn angle. The differential capacitance bridge and the charge integral amplifier were used as the front signal input interface. In the implementation of digital lock-in amplifier, a new routine which warranted the exactly matching of the reference phase to signal phase was proposed. The result of the experiment shows that digital lock-in amplifier can greatly eliminate the noise in the output signal. The non linearity of the turn angle output is 2.3 % and the minimum resolution of turn angle is 0.04 degrees. The application of the software demodulation in the signal detection of micro-electro-mechanical-system (MEMS) device is a new attempt, and it shows the prospective for a high-performance application.

  6. Fishing amplifies forage fish population collapses.

    Science.gov (United States)

    Essington, Timothy E; Moriarty, Pamela E; Froehlich, Halley E; Hodgson, Emma E; Koehn, Laura E; Oken, Kiva L; Siple, Margaret C; Stawitz, Christine C

    2015-05-26

    Forage fish support the largest fisheries in the world but also play key roles in marine food webs by transferring energy from plankton to upper trophic-level predators, such as large fish, seabirds, and marine mammals. Fishing can, thereby, have far reaching consequences on marine food webs unless safeguards are in place to avoid depleting forage fish to dangerously low levels, where dependent predators are most vulnerable. However, disentangling the contributions of fishing vs. natural processes on population dynamics has been difficult because of the sensitivity of these stocks to environmental conditions. Here, we overcome this difficulty by collating population time series for forage fish populations that account for nearly two-thirds of global catch of forage fish to identify the fingerprint of fisheries on their population dynamics. Forage fish population collapses shared a set of common and unique characteristics: high fishing pressure for several years before collapse, a sharp drop in natural population productivity, and a lagged response to reduce fishing pressure. Lagged response to natural productivity declines can sharply amplify the magnitude of naturally occurring population fluctuations. Finally, we show that the magnitude and frequency of collapses are greater than expected from natural productivity characteristics and therefore, likely attributed to fishing. The durations of collapses, however, were not different from those expected based on natural productivity shifts. A risk-based management scheme that reduces fishing when populations become scarce would protect forage fish and their predators from collapse with little effect on long-term average catches.

  7. Status Report on the Energy Amplifier

    CERN Document Server

    Rubbia, Carlo

    1994-01-01

    0ne year after its first presentation,the Energy Amplifier (EA) Project holds its promises for a environmentally acceptable form of energy extraction from nuclei, namely to eliminate or at least greatly reduce(i) the environmental impact of the long-lived highly radioactive waste;(ii) the possibility of diversions toward military applications;(iii) the risks of an accidental divergence related to the critical operation of the chain reaction and (iv) make a more efficient use of a fuel which is less radio-toxic to extract and more abundant on Earth than Uranium. In these respects the EA (or equivalent scenarios from Los Alamos and elsewhere) is comparable in performance to Thermonuclear Fusion. Bot h approches offer pratically unl;imited fuel resources: the energetic content of Lithium on the Earth's crust needed by Fusion is estimated to be seven times the one of Thorium and they are both adequate for millions of years of very intensived utilisation.However the EA can be built economically,in a variety of siz...

  8. Efficient and Compact Optical Amplifier Using EYDF

    Directory of Open Access Journals (Sweden)

    Sulaiman Wadi Harun

    2010-09-01

    Full Text Available An efficient Erbium/Ytterbium doped fiber amplifier (EYDFA is demonstrated using a 1058nm pumping wavelength, where the amplification is assisted by energy transfer between Yb and Er ions. The energy transfer increases the limit of erbium doping concentration that is imposed by concentration quenching in Erbium-doped fiber (EDF. Therefore, the gain and noise figure are severely degraded with 1480 nm pumping, where the energy transfer cannot be achieved. The use of optical isolator improves the small signal gain and noise figure by about 4.8 dB and 1.6 dB, respectively. By employing a double-pass configuration, a higher gain can be obtained with an expense of a noise figure penalty. The gain improvement of 17.0 dB is obtained at 20 mW and -50 dBm of pump and input signal powers. This shows that the double-pass configuration is an important aspect to consider when designing an efficient EYDFA.

  9. Single Ion Quantum Lock-In Amplifier

    CERN Document Server

    Kotler, Shlomi; Glickman, Yinnon; Keselman, Anna; Ozeri, Roee

    2011-01-01

    We report on the implementation of a quantum analog to the classical lock-in amplifier. All the lock-in operations: modulation, detection and mixing, are performed via the application of non-commuting quantum operators on the electronic spin state of a single trapped Sr+ ion. We significantly increase its sensitivity to external fields while extending phase coherence by three orders of magnitude, to more than one second. With this technique we measure magnetic fields with sensitivity of 25 pT/sqrt(Hz) and light shifts with an uncertainty below 140 mHz after 1320 seconds of averaging. These sensitivities are limited by quantum projection noise and, to our knowledge, are more than two orders of magnitude better than with other single-spin probe technologies. In fact, our reported sensitivity is sufficient for the measurement of parity non-conservation, as well as the detection of the magnetic field of a single electronic-spin one micrometer from an ion-detector with nanometer resolution. As a first application ...

  10. Chemically amplified resist modeling in OPC

    Science.gov (United States)

    Zheng, Xin; Huang, Jason; Kuo, Fred; Kazarian, Aram; Chin, Fook; Fan, Yongfa

    2009-03-01

    The mechanism of chemically amplified resist plays a critical role in the modeling of the latent image. To achieve a practical model which can fit into the time frame of OPC, some simplifications and assumptions have to be made. We introduced regression kernels that take into account best exposure focus difference between isotropic pitch, dense, and line end features for the evaluation of image intensity. It compares the image intensity (signal) over small changes above and/or below the regressed "nominal" image position, which in principle corresponds to evaluating the intensity signal at various depths of a fixed resist profile thus can also be regressed for optimization during model development. Our calibration has shown that the model brought a great improvement in prediction for difficult structures such as dense features at or near the optical resolution limit and 2-dimensional features, which are the limiter of the overall model fitting accuracy for 45nm node and below. By replacing other existing techniques, total number of output kernels used for OPC operation is actually reduced with improvement of model accuracy. This model is proven to be a very effective yet accurate addition to the current OPC technology.

  11. Gold Nanoparticle Labels Amplify Ellipsometric Signals

    Science.gov (United States)

    Venkatasubbarao, Srivatsa

    2008-01-01

    The ellipsometric method reported in the immediately preceding article was developed in conjunction with a method of using gold nanoparticles as labels on biomolecules that one seeks to detect. The purpose of the labeling is to exploit the optical properties of the gold nanoparticles in order to amplify the measurable ellipsometric effects and thereby to enable ultrasensitive detection of the labeled biomolecules without need to develop more-complex ellipsometric instrumentation. The colorimetric, polarization, light-scattering, and other optical properties of nanoparticles depend on their sizes and shapes. In the present method, these size-and-shape-dependent properties are used to magnify the polarization of scattered light and the diattenuation and retardance of signals derived from ellipsometry. The size-and-shape-dependent optical properties of the nanoparticles make it possible to interrogate the nanoparticles by use of light of various wavelengths, as appropriate, to optimally detect particles of a specific type at high sensitivity. Hence, by incorporating gold nanoparticles bound to biomolecules as primary or secondary labels, the performance of ellipsometry as a means of detecting the biomolecules can be improved. The use of gold nanoparticles as labels in ellipsometry has been found to afford sensitivity that equals or exceeds the sensitivity achieved by use of fluorescence-based methods. Potential applications for ellipsometric detection of gold nanoparticle-labeled biomolecules include monitoring molecules of interest in biological samples, in-vitro diagnostics, process monitoring, general environmental monitoring, and detection of biohazards.

  12. Stochastic phenomena in a fiber Raman amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Kalashnikov, Vladimir [Aston Institute of Photonic Technologies, Aston University, Birmingham (United Kingdom); Institute of Photonics, Vienna University of Technology (Austria); Sergeyev, Sergey V. [Aston Institute of Photonic Technologies, Aston University, Birmingham (United Kingdom); Ania-Castanon, Juan Diego [Instituto de Optica CSIC, Madrid (Spain); Jacobsen, Gunnar [Acreo, Kista (Sweden); Popov, Sergei [Royal Institute of Technology (KTH), Stockholm (Sweden)

    2017-01-15

    The interplay of such cornerstones of modern nonlinear fiber optics as a nonlinearity, stochasticity and polarization leads to variety of the noise induced instabilities including polarization attraction and escape phenomena harnessing of which is a key to unlocking the fiber optic systems specifications required in high resolution spectroscopy, metrology, biomedicine and telecommunications. Here, by using direct stochastic modeling, the mapping of interplay of the Raman scattering-based nonlinearity, the random birefringence of a fiber, and the pump-to-signal intensity noise transfer has been done in terms of the fiber Raman amplifier parameters, namely polarization mode dispersion, the relative intensity noise of the pump laser, fiber length, and the signal power. The obtained results reveal conditions for emergence of the random birefringence-induced resonance-like enhancement of the gain fluctuations (stochastic anti-resonance) accompanied by pulse broadening and rare events in the form of low power output signals having probability heavily deviated from the Gaussian distribution. (copyright 2016 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Globalization to amplify economic climate losses

    Science.gov (United States)

    Otto, C.; Wenz, L.; Levermann, A.

    2015-12-01

    Economic welfare under enhanced anthropogenic carbon emissions and associated future warming poses a major challenge for a society with an evolving globally connected economy. Unabated climate change will impact economic output for example through heat-stress-related reductions in productivity. Since meteorologically-induced production reductions can propagate along supply chains, structural changes in the economic network may influence climate-related losses. The role of the economic network evolution for climate impacts has been neither quantified nor qualitatively understood. Here we show that since the beginning of the 21st century the structural change of the global supply network has been such that an increase of spillover losses due to unanticipated climatic events has to be expected. We quantify primary, secondary and higher-order losses from reduced labor productivity under past and present economic and climatic conditions and find that indirect losses are significant and increase with rising temperatures. The connectivity of the economic network has increased in such a way as to foster the propagation of production loss. This supply chain connectivity robustly exhibits the characteristic distribution of self-organized criticality which has been shifted towards higher values since 2001. Losses due to this structural evolution dominated over the effect of comparably weak climatic changes during this decade. Our finding suggests that the current form of globalization may amplify losses due to climatic extremes and thus necessitate structural adaptation that requires more foresight than presently prevalent.

  14. Pulse laser imaging amplifier for advanced ladar systems

    Science.gov (United States)

    Khizhnyak, Anatoliy; Markov, Vladimir; Tomov, Ivan; Murrell, David

    2016-05-01

    Security measures sometimes require persistent surveillance of government, military and public areas Borders, bridges, sport arenas, airports and others are often surveilled with low-cost cameras. Their low-light performance can be enhanced with laser illuminators; however various operational scenarios may require a low-intensity laser illumination with the object-scattered light intensity lower than the sensitivity of the Ladar image detector. This paper discusses a novel type of high-gain optical image amplifier. The approach enables time-synchronization of the incoming and amplifying signals with accuracy <= 1 ns. The technique allows the incoming signal to be amplified without the need to match the input spectrum to the cavity modes. Instead, the incoming signal is accepted within the spectral band of the amplifier. We have gauged experimentally the performance of the amplifier with a 40 dB gain and an angle of view 20 mrad.

  15. A Review of High Voltage Drive Amplifiers for Capacitive Actuators

    DEFF Research Database (Denmark)

    Huang, Lina; Zhang, Zhe; Andersen, Michael A. E.

    2012-01-01

    This paper gives an overview of the high voltage amplifiers, which are used to drive capacitive actuators. The amplifiers for both piezoelectric and DEAP (dielectric electroactive polymer) actuator are discussed. The suitable topologies for driving capacitive actuators are illustrated in detail, ......, including linear as well as switched mode amplifiers. In the past much attention has been paid on the driver for piezoelectric actuator. As DEAP is a type of new material, there is not much literature reference for it.......This paper gives an overview of the high voltage amplifiers, which are used to drive capacitive actuators. The amplifiers for both piezoelectric and DEAP (dielectric electroactive polymer) actuator are discussed. The suitable topologies for driving capacitive actuators are illustrated in detail...

  16. GHz bandwidth noise eater hybrid optical amplifier: design guidelines.

    Science.gov (United States)

    Danion, Gwennaël; Bondu, François; Loas, Goulc'hen; Alouini, Mehdi

    2014-07-15

    This Letter describes the design of an optical amplifier system optimized to reduce the relative intensity noise (RIN) of the input signal, and discloses its performance in terms of intensity noise reduction and bandwidth, without phase noise degradation. This polarization-maintaining amplifier is composed of an erbium-doped fiber amplifier (EDFA) cascaded with a semiconductor optical amplifier (SOA). The EDFA is sized to feed the SOA with a constant power corresponding to the optimal saturation level for noise reduction, through coherent population oscillations. When properly optimized, such an amplifier provides, simultaneously, 17 dB optical gain, 5.4 dB noise factor, and 20 dB reduction of the input-RIN across a 3 GHz bandwidth, without any electronics feedback loop.

  17. Class D audio amplifiers for high voltage capacitive transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis

    voltage capacitive transducers can be constructed with THD+N below 0.1 % and peak efficiency above 80 %. However the complexity of the amplifier combined with the current high cost of components, makes the technology of DEAP based loudspeaker unfeasible. Suggestions to future work in the pursuit...... of high volume, weight, and cost. High efficient class D amplifiers are now widely available offering power densities, that their linear counterparts can not match. Unlike the technology of audio amplifiers, the loudspeaker is still based on the traditional electrodynamic transducer invented by C.W. Rice....... Due to the similarities between the electrostatic loudspeaker and the DEAP transducer, the state-of-the-art has a special focus on amplifiers for electrostatic loudspeakers. Amplifiers for other type of capacitive transducers like piezoelectric ones are also considered. Finally the current state...

  18. Digital Lock-in Amplifier Based on Microcontroller

    Institute of Scientific and Technical Information of China (English)

    An-li TAO; Guo-dong XU; Ke-xue LUO; Gang-ling ZHANG

    2010-01-01

    A method of implementing high cost-effective and highly integrated digital lock-in amplifier with microcontroller is discussed. And the digital lock-in amplifier is more suitable for measuring low-frequency weak signal.Digital signal sequence is obtained through sampling signal measured over an integer number of signal periods, but digital reference sequence is acquired through mathematical operation, then digital phase sensitive detection can be implemented by calculating the cross-correlation function of digital signal sequence and digital reference sequence.In addition, the frequency response and phase character of the digital lock-in amplifier is analyzed. Finally, the designed digital lock-in amplifier is achieved. Experimental results show that the digital lock-in amplifier can be used for measuring weak signal with low ignal-to-noise ratio.

  19. FUNDAMENTAL PHENOMENA IN WOOD RFV DRYING WITH 50-Ohm AMPLIFIER TECHNOLOGY

    OpenAIRE

    Koumoutsakos,Anastasios; Avramidis,Stavros; Hatzikiriakos,Savvas G

    2002-01-01

    Radio frequency/vacuum drying (RFV) experiments were conducted on thick (200-250 mm) softwoods by using a 50-Ohm amplifier as the radio frequency (RF) source. The power densities selected were low to ensure highest quality of the final product and that no internal checking will occur. The effect of dryer pressures and power densities on the drying kinetics and product quality was examined for two different wood species. A number of experimental observations and drying characteristics are anal...

  20. Design and fabrication of an intrinsically gain flattened Erbium doped fiber amplifier

    OpenAIRE

    Nagaraju, B.; Paul, M.C.; Pal, M.; Pal, A.; Varshney, Ravi K.; Pal, Bishnu; Bhadra, S.K.; Monnom, Gérard; Dussardier, Bernard

    2009-01-01

    International audience; We report design and subsequent fabrication of an intrinsically gain flattened Erbium doped fiber amplifier (EDFA) based on a highly asymmetrical and concentric dual-core fiber, inner core of which was only partially doped. Phase-resonant optical coupling between the two cores was so tailored through optimization of its refractive index profile parameters that the longer wavelengths within the C-band experience relatively higher amplification compared to the shorter wa...

  1. Improved electroabsorption demultiplexer by tandem-arrangement with semiconductor optical amplifier

    DEFF Research Database (Denmark)

    Hilliger, E.; Marembert, V.; Schubert, C.;

    2002-01-01

    control. In this experiment a mode locked laser was used to control the SOA. However, it should be sufficient to use a gain-switched DFB-laser. The advantage of this scheme is that no electronic devices for frequencies higher than 10 GHz are required and no additional RF-source or RF-amplifier is needed...... for the control laser. The set-up is very robust, especially because it does not base on interferometric or polarization sensitive effects....

  2. Experimental Characterization of the Seeded FEL Amplifier at the BNL SDL

    CERN Document Server

    Watanabe, T; Murphy, J B; Rose, J; Shaftan, T V; Tsang, Thomas; Wang, X J; Yu, L H

    2005-01-01

    A laser seeded near IR FEL amplifier experiment was initiated at the BNL SDL [1] to explore various schemes of FEL efficiency improvement and generation of short Rayleigh length (SRL) FEL output. The FEL achieved first SASE lasing at 0.8 μm on May 6, 2005. The experimental characterization of the laser seeded FEL output power, spectrum and transverse mode structure evolution will be presented.

  3. A Gallium Arsenide MESFET Operational Amplifier for Use in Composite Operational Amplifiers

    Science.gov (United States)

    1993-12-01

    F., Operational Amplifiers and Linear Integrated Circuits, 4th ed., Prentice Hall, 1991. 6. Sedra , A. S., and Smith , K. C., Microelectronic Circuits...7, pp. 1422-1429, July 1992. 17. McCamant, A. J., McCormack G. D., and Smith , D. H., "An Improved GaAs MESFET Model for SPICE," IEEE Transactions of...34Modeling Frequency Dependence of out Impedance of a Microwave MESFET at Low Frequencies," Electronics Letters, pp. 528-529, June 1985. 39. Smith , M. et al

  4. A modular positive feedback-based gene amplifier

    Directory of Open Access Journals (Sweden)

    Bhalerao Kaustubh D

    2010-02-01

    Full Text Available Abstract Background Positive feedback is a common mechanism used in the regulation of many gene circuits as it can amplify the response to inducers and also generate binary outputs and hysteresis. In the context of electrical circuit design, positive feedback is often considered in the design of amplifiers. Similar approaches, therefore, may be used for the design of amplifiers in synthetic gene circuits with applications, for example, in cell-based sensors. Results We developed a modular positive feedback circuit that can function as a genetic signal amplifier, heightening the sensitivity to inducer signals as well as increasing maximum expression levels without the need for an external cofactor. The design utilizes a constitutively active, autoinducer-independent variant of the quorum-sensing regulator LuxR. We experimentally tested the ability of the positive feedback module to separately amplify the output of a one-component tetracycline sensor and a two-component aspartate sensor. In each case, the positive feedback module amplified the response to the respective inducers, both with regards to the dynamic range and sensitivity. Conclusions The advantage of our design is that the actual feedback mechanism depends only on a single gene and does not require any other modulation. Furthermore, this circuit can amplify any transcriptional signal, not just one encoded within the circuit or tuned by an external inducer. As our design is modular, it can potentially be used as a component in the design of more complex synthetic gene circuits.

  5. A Low Noise Amplifier for Neural Spike Recording Interfaces

    Directory of Open Access Journals (Sweden)

    Jesus Ruiz-Amaya

    2015-09-01

    Full Text Available This paper presents a Low Noise Amplifier (LNA for neural spike recording applications. The proposed topology, based on a capacitive feedback network using a two-stage OTA, efficiently solves the triple trade-off between power, area and noise. Additionally, this work introduces a novel transistor-level synthesis methodology for LNAs tailored for the minimization of their noise efficiency factor under area and noise constraints. The proposed LNA has been implemented in a 130 nm CMOS technology and occupies 0.053 mm-sq. Experimental results show that the LNA offers a noise efficiency factor of 2.16 and an input referred noise of 3.8 μVrms for 1.2 V power supply. It provides a gain of 46 dB over a nominal bandwidth of 192 Hz–7.4 kHz and consumes 1.92 μW. The performance of the proposed LNA has been validated through in vivo experiments with animal models.

  6. A Low Noise Amplifier for Neural Spike Recording Interfaces

    Science.gov (United States)

    Ruiz-Amaya, Jesus; Rodriguez-Perez, Alberto; Delgado-Restituto, Manuel

    2015-01-01

    This paper presents a Low Noise Amplifier (LNA) for neural spike recording applications. The proposed topology, based on a capacitive feedback network using a two-stage OTA, efficiently solves the triple trade-off between power, area and noise. Additionally, this work introduces a novel transistor-level synthesis methodology for LNAs tailored for the minimization of their noise efficiency factor under area and noise constraints. The proposed LNA has been implemented in a 130 nm CMOS technology and occupies 0.053 mm-sq. Experimental results show that the LNA offers a noise efficiency factor of 2.16 and an input referred noise of 3.8 μVrms for 1.2 V power supply. It provides a gain of 46 dB over a nominal bandwidth of 192 Hz–7.4 kHz and consumes 1.92 μW. The performance of the proposed LNA has been validated through in vivo experiments with animal models. PMID:26437411

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

    Science.gov (United States)

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

    2012-10-01

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

  8. Amplifier circuit operable over a wide temperature range

    Science.gov (United States)

    Kelly, Ronald D.; Cannon, William L.

    1979-01-01

    An amplifier circuit having stable performance characteristics over a wide temperature range from approximately 0.degree. C up to as high as approximately 500.degree. C, such as might be encountered in a geothermal borehole. The amplifier utilizes ceramic vacuum tubes connected in directly coupled differential amplifier pairs having a common power supply and a cathode follower output stage. In an alternate embodiment, for operation up to 500.degree. C, positive and negative power supplies are utilized to provide improved gain characteristics, and all electrical connections are made by welding. Resistor elements in this version of the invention are specially heat treated to improve their stability with temperature.

  9. Investigation of a background suppression transimpedance amplifier for photovoltaic detectors

    Science.gov (United States)

    Metzger, Ferdinand J., Jr.

    1992-12-01

    The current generation of transimpedance amplifier based detector systems are limited by opamp saturation when operating at a high gain or in the presence of a large background signal. To eliminate saturation, an amplifier that is frequency dependent is developed. Additionally, the noise sources in the conventional transimpedance amplifier and photovoltaic detector are quantified for comparison to any modified circuit. Initial results indicate that the frequency dependent detector system is a viable system, however, further development is required. Further research of this technology is expected to support future infrared and long range detection applications.

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

    Science.gov (United States)

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

    2008-01-01

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

  11. 2250-MHz High Efficiency Microwave Power Amplifier (HEMPA)

    Science.gov (United States)

    Sims, W. Herbert; Bell, Joseph L. (Technical Monitor)

    2001-01-01

    Tnis paper will focus on developing an exotic switching technique that enhances the DC-to-RF conversion efficiency of microwave power amplifiers. For years, switching techniques implemented in the 10 kHz to 30 MHz region have resulted in DC-to-RF conversion efficiencies of 90-95-percent. Currently amplifier conversion efficiency, in the 2-3 GHz region approaches, 10-20-percent. Using a combination of analytical modeling and hardware testing, a High Efficiency Microwave Power Amplifier was built that demonstrated conversion efficiencies four to five times higher than current state of the art.

  12. Efficient performance simulation of class D amplifier output stages

    DEFF Research Database (Denmark)

    Nyboe, Flemming; Risbo, Lars; Andreani, Pietro

    2005-01-01

    Straightforward simulation of amplifier distortion involves transient simulation of operation on a sine wave input signal, and a subsequent FFT of the output voltage. This approach is very slow on class D amplifiers, since the switching behavior forces simulation time steps that are many orders...... of magnitude smaller than the duration of one period of an audio sine wave. This work presents a method of simulating the amplifier transfer characteristic using a minimum amount of simulation time, and then deriving THD from the results....

  13. Design procedure for optimizing CMOS low noise operational amplifiers

    Institute of Scientific and Technical Information of China (English)

    Li Zhiyuan; Ye Yizheng; Ma Jianguo

    2009-01-01

    This paper presents and experimentally verifies an optimized design procedure for a CMOS low noise operational amplifier.The design procedure focuses on the noise performance,which is the key requirement for low noise operational amplifiers.Based on the noise level and other specifications such as bandwidth,signal swing,slew rate,and power consumption,the device sizes and the biasing conditions are derived.In order to verify the proposed design procedure,a three-stage operational amplifier has been designed.The device parameters obtained from the proposed design procedure closely agree with the simulated results obtained by using HSPICE.

  14. Introduction to RF power amplifier design and simulation

    CERN Document Server

    Eroglu, Abdullah

    2015-01-01

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

  15. Minimizing Crosstalk in Self Oscillating Switch Mode Audio Power Amplifiers

    DEFF Research Database (Denmark)

    Knott, Arnold; Ploug, Rasmus Overgaard

    2012-01-01

    The varying switching frequencies of self oscillating switch mode audio amplifiers have been known to cause interchannel intermodulation disturbances in multi channel configurations. This crosstalk phenomenon has a negative impact on the audio performance. The goal of this paper is to present...... a method to minimize this phenomenon by improving the integrity of the various power distribution systems of the amplifier. The method is then applied to an amplifier built for this investigation. The results show that the crosstalk is suppressed with 30 dB, but is not entirely eliminated...

  16. Optimization and Performance Analysis of Bulk-Driven Differential Amplifier

    Directory of Open Access Journals (Sweden)

    Antarpreet kaur

    2014-04-01

    Full Text Available In recent years, there has been an increasing demand for high-speed digital circuits at low power consumption. This paper presents a design of input stage of Operational Amplifier i.e cascode differential amplifier using a standard 65nm CMOS Technology.A comparison betweem gate-driven, bulk-driven and cascode bulk driven bulk-driven differential amplifier is described. The Results demonstrate that CMMR is 83.98 dB, 3-dB Bandwidth is 1.04 MHz. The circuit dissipate power of 28uWunder single supply of 1.0V.

  17. Design of High Power Density Amplifiers: Application to Ka Band

    Science.gov (United States)

    Passi, Davide; Leggieri, Alberto; Di Paolo, Franco; Bartocci, Marco; Tafuto, Antonio

    2017-06-01

    Recent developments in the design of high-power-high-frequency amplifiers are assessed in this paper by the analysis and measurements of a high power density amplifier operating in the Ka Band. Design procedure is presented and a technical investigation is reported. The proposed device has shown over 23% of useful frequency bandwidth. It is an ensemble of 16 monolithic solid state power amplifiers that employees mixed technologies as spatial and planar combiners. Test performed have given maximum delivered power of 47.2 dBm.

  18. Modal analysis of a large-mode area photonic crystal fiber amplifier using spectral-resolved imaging

    DEFF Research Database (Denmark)

    Laurila, Marko; Alkeskjold, Thomas T.; Lægsgaard, Jesper

    2011-01-01

    We perform modal characterization on an ytterbium-doped large mode area photonic-crystal-fiber (PCF) amplifier using spatial and spectral (S 2) resolved imaging and compare results to conventional cutoff methods. We apply numerical simulations and step-index fiber experiments to calibrate our...

  19. Non-saturable absorption and its impact on amplifier performance in Al2O3:Er3+

    NARCIS (Netherlands)

    Agazzi, L.; Wörhoff, K.; Pollnau, M.

    2011-01-01

    Luminescence decay and non-saturable absorption experiments in erbium-doped aluminum oxide waveguides determine the energy-transfer-upconversion parameter and reveal the presence of quenched ions. We quantify the percentage of quenched ions and their impact on amplifier performance.

  20. Synergistic effect of mixed neutron and gamma irradiation in bipolar operational amplifier OP07

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Liu, E-mail: liuyan@nint.ac.cn [State Key Laboratory of Intense Pulsed Irradiation Simulation and Effect, Northwest Institute of Nuclear Technology, P.O.Box 69-10, Xi’an 710024 (China); School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049 (China); Wei, Chen; Shanchao, Yang; Xiaoming, Jin [State Key Laboratory of Intense Pulsed Irradiation Simulation and Effect, Northwest Institute of Nuclear Technology, P.O.Box 69-10, Xi’an 710024 (China); Chaohui, He [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049 (China)

    2016-09-21

    This paper presents the synergistic effects in bipolar operational amplifier OP07. The radiation effects are studied by neutron beam, gamma ray, and mixed neutron/gamma ray environments. The characterateristics of the synergistic effects are studied through comparison of different experiment results. The results show that the bipolar operational amplifier OP07 exhibited significant synergistic effects in the mixed neutron and gamma irradiation. The bipolar transistor is identified as the most radiation sensitive unit of the operational amplifier. In this paper, a series of simulations are performed on bipolar transistors in different radiation environments. In the theoretical simulation, the geometric model and calculations based on the Medici toolkit are built to study the radiation effects in bipolar components. The effect of mixed neutron and gamma irradiation is simulated based on the understanding of the underlying mechanisms of radiation effects in bipolar transistors. The simulated results agree well with the experimental data. The results of the experiments and simulation indicate that the radiation effects in the bipolar devices subjected to mixed neutron and gamma environments is not a simple combination of total ionizing dose (TID) effects and displacement damage. The data suggests that the TID effect could enhance the displacement damage. The synergistic effect should not be neglected in complex radiation environments.

  1. Coherent control in room-temperature quantum dot semiconductor optical amplifiers using shaped pulses

    CERN Document Server

    Karni, Ouri; Eisenstein, Gadi; Ivanov, Vitalii; Reithmaier, Johann Peter

    2016-01-01

    We demonstrate the ability to control quantum coherent Rabi-oscillations in a room-temperature quantum dot semiconductor optical amplifier (SOA) by shaping the light pulses that trigger them. The experiments described here show that when the excitation is resonant with the short wavelength slope of the SOA gain spectrum, a linear frequency chirp affects its ability to trigger Rabi-oscillations within the SOA: A negative chirp inhibits Rabi-oscillations whereas a positive chirp can enhance them, relative to the interaction of a transform limited pulse. The experiments are confirmed by a numerical calculation that models the propagation of the experimentally shaped pulses through the SOA.

  2. Robust entanglement between a movable mirror and a cavity field system with an optical parametric amplifier

    Science.gov (United States)

    Mi, Xianwu; Bai, Jiangxiang; Ke-hui, Song

    2013-06-01

    Robust entanglement created between an optical cavity field mode and a macroscopic vibrating mirror with an optical parametric amplifier is shown. Increasing the gain of the optical parametric amplifier makes the line of the logarithmic negativity E N move to the range of the larger detuning and higher temperature. Such optomechanical entanglement can be generated even at room temperature with current experimental parameters. Compared with other proposals, we have considered the one-to-one correspondence between the detuning and the input power, which is reasonable with the fact that the mean shift of the cavity frequency is determined by the radiation pressure which is related to the input power. Such consideration may be valuable to current experiments.

  3. High Power Amplifiers Chain nonlinearity influence on the accelerating beam stability in free electron laser (FLASH)

    CERN Document Server

    Cichalewski, w

    2010-01-01

    The high power amplifiers transfer characteristics nonlinearities can have a negative influence on the overall system performance. This is also true for the TESLA superconducting cavities accelerating field parameters control systems. This Low Level Radio Frequency control systems uses microwave high power amplifiers (like 10 MW klystrons) as actuators in the mentioned feedback loops. The amplitude compression and phase deviations phenomena introduced to the control signals can reduce the feedback performance and cause electron beam energy instabilities. The transfer characteristics deviations in the Free Electron Laser in Hamburg experiment have been investigated. The outcome of this study together with the description of the developed linearization method based on the digital predistortion approach have been described in this paper. Additionally, the results from the linearization tool performance tests in the FLASH's RF systems have been placed.

  4. Amplified spontaneous emission spectrum at the output of a diode amplifier saturated by an input monochromatic wave

    Science.gov (United States)

    Bogatov, A. P.; Drakin, A. E.; D'yachkov, N. V.; Gushchik, T. I.

    2016-08-01

    Expressions for the amplitudes of amplified spontaneous emission waves in a diode amplifier near the frequency ω0 of a 'strong' input monochromatic wave have been derived in terms of a random function of a stationary Gaussian process. We have found expressions for the spectral density of the amplitudes and shown that, on the red side of the spectrum with respect to frequency ω0, spontaneous emission waves obtain additional nonlinear gain, induced by the strong wave, whereas on the blue side of the spectrum an additional loss is induced. Such behaviour of the amplitudes of amplified waves agrees with previous results.

  5. Amplifying waveguide optical isolator with an integrated electromagnet

    OpenAIRE

    2007-01-01

    We have demonstrated an amplifying waveguide optical isolator with an integrated electromagnet. This provides a solution to the generally poor magnetic remanence of this type of isolator. The proof of principle is presented and optimization routes are discussed.

  6. Magnetic Bearing Amplifier Output Power Filters for Flywheel Systems

    Science.gov (United States)

    Lebron-Velilla, Ramon C.; Jansen, Ralph H.; Palazzolo, Alan; Thomas, Erwin; Kascak, Peter E.; Birchenough, Arthur G.; Dever, Timothy P.

    2003-01-01

    Five power filters and two types of power amplifiers were tested for use with active magnetic bearings for flywheel applications. Filter topologies included low pass filters and low pass filters combined with trap filters at the PWM switching frequency. Two state and three state PWM amplifiers were compared. Each system was evaluated based on current magnitude at the switching frequency, voltage magnitude at 500 kHz, and power consumption. The base line system was a two state amplifier without a power filter. The recommended system is a three state power amplifier with a 50 kHz low pass filter and a 27 kHz trap filter. This system uses 5.57 W. It reduces the switching current by an order of magnitude and the 500 kHz voltage by two orders of magnitude. The relative power consumption varied depending on the test condition between 60 to 130 percent of the baseline.

  7. 1.55 Micron High Peak Power Fiber Amplifier Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this proposal, we propose to demonstrate and build a 1.55 micron single frequency high energy and high peak power fiber amplifier by developing an innovative...

  8. Gain Variation with Raman Amplifier Parameters and Its Restoration

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    We demonstrate that gain profile of a distributed Raman amplifier is sensitive to its parameter variation, such as loss/gain coefficients change or partial pump failure. Gain flatness can be restored by adjusting power of pump lasers.

  9. High current density nanofilament cathodes for microwave amplifiers

    NARCIS (Netherlands)

    Schnell, J-P.; Minoux, E.; Gangloff, L.; Vincent, P.; Legagneux, P.; Dieumegard, D.; David, J.-F.; Peauger, F.; Hudanski, L.; Teo, K.B.K.; Lacerda, R.; Chhowalla, M.; Hasko, D.G.; Ahmed, H.; Amaratunga, G.A.J.; Milne, W.I.; Vila, L.; Dauginet-De Pra, L.; Demoustier-Champagne, S.; Ferain, E.; Legras, R.; Piraux, L.; Gröening, O.; Raedt, H. De; Michielsen, K.

    2004-01-01

    We study high current density nanofilament cathodes for microwave amplifiers. Two different types of aligned nanofilament array have been studied: first, metallic nanowires grown by electrodeposition into nanoporous templates at very low temperature (T

  10. A CMOS single-supply logarithmic amplifier for hearing aids

    Science.gov (United States)

    Jarng, Soon Suck; Chen, Lingfeng; Kwon, You Jung

    2005-12-01

    The Log Amplifier described in this paper is designed for hearing aids (HA) application. It works on a low single-supply voltage (1.3V). The input signal varies between 0.01mV and 100mV. To give enough compensation to the hearing impairment, the amplifier provides a very large gain. The output swing is limited because of the low supply voltage and the large gain. Therefore, the logarithmic amplifier introduced into the design of HA to compress input signal so that the output distortion can be avoid. Another factor we use it here is that the amplifier has enough sensitivity and gain to deal with the compressed input signal without getting extra distortion coursed by the pre-process on input signal. The short channel CMOS devices play an important role in reduction of the supply voltage. DONG-BU ANAM 0.18 μm process is selected.

  11. High-Frequency RIN Transfer in Fibre Optic Parametric Amplifiers

    DEFF Research Database (Denmark)

    Lali-Dastjerdi, Zohreh; Lund-Hansen, Toke; Kang, Ning

    2011-01-01

    ibre optic parametric amplifiers (FOPAs) are versatile devices for amplification at arbitrary wavelengths, as well as a wide range of optical signal processing applications, including switching, wavelength conversion, regeneration, pulse generation etc [1]. Transfer of intensity fluctuations from...

  12. 1.55 Micron High Peak Power Fiber Amplifier Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this proposal, we propose to demonstrate and build a 1.55 micron single frequency high energy and high peak power fiber amplifier by developing an innovative...

  13. Common source cascode amplifiers for integrating IR-FPA applications

    Science.gov (United States)

    Woolaway, James T.; Young, Erick T.

    1989-01-01

    Space based astronomical infrared measurements present stringent performance requirements on the infrared detector arrays and their associated readout circuitry. To evaluate the usefulness of commercial CMOS technology for astronomical readout applications a theoretical and experimental evaluation was performed on source follower and common-source cascode integrating amplifiers. Theoretical analysis indicates that for conditions where the input amplifier integration capacitance is limited by the detectors capacitance the input referred rms noise electrons of each amplifier should be equivalent. For conditions of input gate limited capacitance the source follower should provide lower noise. Measurements of test circuits containing both source follower and common source cascode circuits showed substantially lower input referred noise for the common-source cascode input circuits. Noise measurements yielded 4.8 input referred rms noise electrons for an 8.5 minute integration. The signal and noise gain of the common-source cascode amplifier appears to offer substantial advantages in acheiving predicted noise levels.

  14. Fiber amplifiers under thermal loads leading to transverse mode instability

    DEFF Research Database (Denmark)

    Johansen, Mette Marie; Hansen, Kristian Rymann; Alkeskjold, Thomas Tanggaard;

    2014-01-01

    Transverse mode instability (TMI) in rare-earth doped fiber amplifiers operating above an average power threshold is caused by intermodal stimulated thermal Rayleigh scattering due to quantum defect heating. We investigate thermally induced longitudinal waveguide perturbations causing power trans...

  15. A high-fidelity noiseless amplifier for quantum light states

    CERN Document Server

    Zavatta, A; Bellini, M

    2010-01-01

    Noise is the price to pay when trying to clone or amplify arbitrary quantum states. The quantum noise associated to linear phase-insensitive amplifiers can only be avoided by relaxing the requirement of a deterministic operation. Here we present the experimental realization of a probabilistic noiseless linear amplifier that is able to amplify coherent states at the highest level of effective gain and final state fidelity ever reached. Based on a sequence of photon addition and subtraction, and characterized by a significant amplification and low distortions, this high-fidelity amplification scheme may become an essential tool for quantum communications and metrology, by enhancing the discrimination between partially overlapping quantum states or by recovering the information transmitted over lossy channels.

  16. Hearing Aids and Personal Sound Amplifiers: Know the Difference

    Science.gov (United States)

    ... Products For Consumers Home For Consumers Consumer Updates Hearing Aids and Personal Sound Amplifiers: Know the Difference ... today. back to top Signs of Loss of Hearing Mann says that consumers who suspect they suffer ...

  17. On the unlimited gain of a nonlinear parametric amplifier

    DEFF Research Database (Denmark)

    Sorokin, Vladislav

    2014-01-01

    The present paper is concerned with analysis of the response of a nonlinear parametric amplifier in abroad range of system parameters, particularly beyond resonance. Such analysis is of particular interestfor micro- and nanosystems, since many small-scale parametric amplifiers exhibit a distinctly...... nonlinearbehavior when amplitude of their response is sufficiently large. The modified method of direct separa-tion of motions is employed to study the considered system. As the result it is obtained that steady-stateamplitude of the nonlinear parametric amplifier response can reach large values in the case...... of arbitrarilysmall amplitude of external excitation, so that the amplifier gain tends to infinity. Very large amplifiergain can be achieved in a broad range of system parameters, in particular when the amplitude of para-metric excitation is comparatively small. The obtained results clearly demonstrate that very...

  18. Experimental examinations of semiconductor laser amplifiers for optical communication technology

    Science.gov (United States)

    Ludwig, Reinhold

    1993-01-01

    Properties of SLA (Semiconductor Laser Amplifier), which are particularly interesting for application to linear repeaters in coherent multichannel systems, are studied and design rules for future optimized amplifier structure are deduced. Laser diode antireflection was examined and reflection factor was measured. Low signal properties were discussed considering injection current, wavelengths, temperature and polarization. The coupling between amplifiers and glass fibers was examined. The utilization of cascade amplifiers as linear repeaters in multichannel heterodyne systems and television distribution systems was investigatied. The following results are obtained: measurement and calculation of the paradiaphony between two signals radiated in a SLA; multichannel data transfer through a SLA; polarization independent amplification with SLA configurations; measurement of the frequency dependence of four wave mixing sidelines in a SLA; measurement of the system degradation through echoes in a bidirectional SLA chain; data transmission with frequency conversion and calculation of multichannel transmission systems with cascade SLA, taking into account saturation, signal to noise ratio, bandwidth reduction and echo.

  19. Distributed CMOS Bidirectional Amplifiers Broadbanding and Linearization Techniques

    CERN Document Server

    El-Khatib, Ziad; Mahmoud, Samy A

    2012-01-01

    This book describes methods to design distributed amplifiers useful for performing circuit functions such as duplexing, paraphrase amplification, phase shifting power splitting and power combiner applications.  A CMOS bidirectional distributed amplifier is presented that combines for the first time device-level with circuit-level linearization, suppressing the third-order intermodulation distortion. It is implemented in 0.13μm RF CMOS technology for use in highly linear, low-cost UWB Radio-over-Fiber communication systems. Describes CMOS distributed amplifiers for optoelectronic applications such as Radio-over-Fiber systems, base station transceivers and picocells; Presents most recent techniques for linearization of CMOS distributed amplifiers; Includes coverage of CMOS I-V transconductors, as well as CMOS on-chip inductor integration and modeling; Includes circuit applications for UWB Radio-over-Fiber networks.

  20. Application of random amplified polymorphic DNA (RAPD) markers ...

    African Journals Online (AJOL)

    Application of random amplified polymorphic DNA (RAPD) markers to ... used, 108 primers generated RAPD bands from genomic DNA of T. chinensis var. mairei ... Keywords: Cultivar identification, DNA extraction, parthenogenesis, pedigree, ...

  1. Fast terahertz imaging using a quantum cascade amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Yuan, E-mail: yr235@cam.ac.uk; Wallis, Robert; Jessop, David Stephen; Degl' Innocenti, Riccardo; Klimont, Adam; Beere, Harvey E.; Ritchie, David A. [Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom)

    2015-07-06

    A terahertz (THz) imaging scheme based on the effect of self-mixing in a 2.9 THz quantum cascade (QC) amplifier has been demonstrated. By coupling an antireflective-coated silicon lens to the facet of a QC laser, with no external optical feedback, the laser mirror losses are enhanced to fully suppress lasing action, creating a THz QC amplifier. The addition of reflection from an external target to the amplifier creates enough optical feedback to initiate lasing action and the resulting emission enhances photon-assisted transport, which in turn reduces the voltage across the device. At the peak gain point, the maximum photon density coupled back leads to a prominent self-mixing effect in the QC amplifier, leading to a high sensitivity, with a signal to noise ratio up to 55 dB, along with a fast data acquisition speed of 20 000 points per second.

  2. A dual-amplifier hot-wire anemometer

    Science.gov (United States)

    Sadeh, W. Z.; Finn, C. L.

    1979-01-01

    The conceptual design of a dual-amplifier constant-temperature hot-wire anemometer is described. This hot-wire anemometer consists of three basic independent modules: a Wheatstone bridge in which the hot wire is one of its arms, an error-correction amplifier, and a voltage-controlled current source. The last two modules constitute the feedback network of this hot-wire anemometer. Thus the output voltage across the wire is a true function of the instantaneous changes in the wire resistance induced by the cooling effect of the flow. The dual-amplifier is capable of reaching relatively high frequency response through adequate selection of its active elements. Suitable gain of the error-correction amplifier and proper choice of the transfer function of the current source has yielded a frequency bandwidth up to 200 kHz.

  3. Design of low noise transimpedance amplifier for intravascular ultrasound

    KAUST Repository

    Reda, Dina

    2009-11-01

    In this paper, we study transimpedance amplifiers for capacitive sensing applications with a focus on Intravascular Ultra Sound (IVUS). We employ RF noise cancellation technique on capacitive feedback based transimpedance amplifiers. This technique eliminates the input-referred noise of TIAs completely and enhances the dynamic range of front-end electronics. Simulation results verify the proposed technique used in two different TIA topologies employing shunt-shunt feedback. ©2009 IEEE.

  4. An Artefact suppressing fast-recovery myoelectric amplifier

    OpenAIRE

    1999-01-01

    An amplifier for recording myoelectric signals using surface electrodes has been developed. The special features are suppression of stimulation artefacts and motion artefacts from electrodes. It is designed for recording of myoelectric signals from a muscle that is being stimulated with short impulses. The artifact suppression is achieved by using fast-recovery instrumentation amplifiers and having a nonlinear feedback loop for automatic compensation of changes in DC-offset

  5. Design of 2.1 GHz CMOS Low Noise Amplifier

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper discusses the design of a fully differential 2.1 GHz CMOS low noise amplifier using the TSMC0.25 μm CMOS process. Intended for use in 3G, the low noise amplifier is fully integrated and without off-chip components. The design uses an LC tank to replace a large inductor to achieve a smaller die area, and uses shielded pad capacitances to improve the noise performance. This paper also presents evaluation results of the design.

  6. Design of Enhanced Performance Folded Cascoded Operational Transconductance Amplifier

    Science.gov (United States)

    Soni, Priyanka; Singh, B. P.; Bhardwaj, Monika

    2010-11-01

    This paper presents a modified folded cascode transconductance amplifier. Inclusion of an extra stage and compensation network in the proposed amplifier enhanced the performance over the conventional folded. The proposed circuit offers good trade-off on the conflicting performance parameters such as bandwidth, slew rate, d.c. gain, phase margin and settling time. The simulation has been carried out on Tanner EDA tool on TSMC 180 nm technology.

  7. Ultrafast optical signal processing using semiconductor quantum dot amplifiers

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Mørk, Jesper

    2002-01-01

    The linear and nonlinear properties of quantum dot amplifiers are discussed on the basis of an extensive theoretical model. These devices show great potential for linear amplification as well as ultrafast signal processing.......The linear and nonlinear properties of quantum dot amplifiers are discussed on the basis of an extensive theoretical model. These devices show great potential for linear amplification as well as ultrafast signal processing....

  8. On the dual symmetry between absorbing and amplifying random media

    Indian Academy of Sciences (India)

    S Anantha Ramakrishna

    2004-06-01

    We re-examine the dual symmetry between absorbing and amplifying random media. By analysing the physically allowed choice of the sign of the square root to determine the complex wave vector in a medium, we draw a broad set of conclusions that enables us to resolve the apparent paradox of the dual symmetry and also to anticipate the large local electromagnetic field enhancements in amplifying random media.

  9. Thermally induced nonlinear mode coupling in high power fiber amplifiers

    DEFF Research Database (Denmark)

    Johansen, Mette Marie; Hansen, Kristian Rymann; Alkeskjold, Thomas T.;

    2013-01-01

    Thermally induced nonlinear mode coupling leads to transverse mode instability (TMI) in high power fiber amplifiers. A numerical model including altering mode profiles from thermal effects and waveguide perturbations predicts a TMI threshold of ~200W.......Thermally induced nonlinear mode coupling leads to transverse mode instability (TMI) in high power fiber amplifiers. A numerical model including altering mode profiles from thermal effects and waveguide perturbations predicts a TMI threshold of ~200W....

  10. EXAMINING OF ASE AT THE ERBIUM DOPED FIBER AMPLIFIERS

    Directory of Open Access Journals (Sweden)

    H. Haldun GÖKTAŞ

    2004-02-01

    Full Text Available In this study, the effect of Amplified Spontaneous Emission (ASE which is the main cause of noise in Erbium Doped-Fiber Amplifiers (EDFA used in long distance signal transmission has been examined. For this purpose an EDFA pumped with a 1480nm pump source has been analysed to see the effect of ASE, by taking into account the noise and removing it from the simulation.

  11. Characterization of a multimode coplanar waveguide parametric amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Simoen, M., E-mail: simoen@chalmers.se; Krantz, P.; Bylander, Jonas; Shumeiko, V.; Delsing, P. [Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, Göteborg SE-412 96 (Sweden); Chang, C. W. S.; Wilson, C. M. [Institute for Quantum Computing and Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Wustmann, W. [Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, Göteborg SE-412 96 (Sweden); Laboratory for Physical Sciences, College Park, Maryland 20740 (United States)

    2015-10-21

    We characterize a Josephson parametric amplifier based on a flux-tunable quarter-wavelength resonator. The fundamental resonance frequency is ∼1 GHz, but we use higher modes of the resonator for our measurements. An on-chip tuning line allows for magnetic flux pumping of the amplifier. We investigate and compare degenerate parametric amplification, involving a single mode, and nondegenerate parametric amplification, using a pair of modes. We show that we reach quantum-limited noise performance in both cases.

  12. Thermal Effects in High-Power Fiber Amplifiers

    DEFF Research Database (Denmark)

    Hansen, Kristian Rymann; Lægsgaard, Jesper

    2011-01-01

    The effect of temperature gradients in Yb-doped fiber amplifiers is studied numerically. We investigate the dependence of the mode area on the signal power, and compare forward and backward pumping schemes.......The effect of temperature gradients in Yb-doped fiber amplifiers is studied numerically. We investigate the dependence of the mode area on the signal power, and compare forward and backward pumping schemes....

  13. Ferrite bead effect on Class-D amplifier audio quality

    OpenAIRE

    Haddad, Kevin El; Mrad, Roberto; Morel, Florent; Pillonnet, Gael; Vollaire, Christian; Nagari, Angelo

    2014-01-01

    International audience; This paper studies the effect of ferrite beads on the audio quality of Class-D audio amplifiers. This latter is a switch-ing circuit which creates high frequency harmonics. Generally, a filter is used at the amplifier output for the sake of electro-magnetic compatibility (EMC). So often, in integrated solutions, this filter contains ferrite beads which are magnetic components and present nonlinear behavior. Time domain measurements and their equivalence in frequency do...

  14. ANALYSIS OF INTERNALLY GENERATED NOISE OF BIOELECTRIC AMPLIFIERS

    Institute of Scientific and Technical Information of China (English)

    MashhourMustafaBaniAmer

    2003-01-01

    This papenr deals with internally generated noise of bioelectric amplifiers that are usually used for processing of bioelectric events.The main purpose of this paper is to present a procedure for analysis of the effects of internal noise generated by the active circuits and to evaluate the output noise of the author's new designed bioelectric amplifier that caused by internal effects to the amplifier circuit itself in order to compare it with the noise generated by conventional amplifiers.The obtained analysis results of internally generated noise showed that the total output noise of bioelectric active circuits does not increase when some of their resitors have a larger value.This behavior is caused by the different transfer functions for the signal and the respective noise sources associated with these resistors.Moreover,the new designed bioelectric amplifier haws an output noise less than that for conventional amplifiers.The obtained analysis results were also experimentally verified and the final conclusions were drawn.

  15. High Efficiency Microwave Power Amplifier: From the Lab to Industry

    Science.gov (United States)

    Sims, William Herbert, III; Bell, Joseph L. (Technical Monitor)

    2001-01-01

    Since the beginnings of space travel, various microwave power amplifier designs have been employed. These included Class-A, -B, and -C bias arrangements. However, shared limitation of these topologies is the inherent high total consumption of input power associated with the generation of radio frequency (RF)/microwave power. The power amplifier has always been the largest drain for the limited available power on the spacecraft. Typically, the conversion efficiency of a microwave power amplifier is 10 to 20%. For a typical microwave power amplifier of 20 watts, input DC power of at least 100 watts is required. Such a large demand for input power suggests that a better method of RF/microwave power generation is required. The price paid for using a linear amplifier where high linearity is unnecessary includes higher initial and operating costs, lower DC-to-RF conversion efficiency, high power consumption, higher power dissipation and the accompanying need for higher capacity heat removal means, and an amplifier that is more prone to parasitic oscillation. The first use of a higher efficiency mode of power generation was described by Baxandall in 1959. This higher efficiency mode, Class-D, is achieved through distinct switching techniques to reduce the power losses associated with switching, conduction, and gate drive losses of a given transistor.

  16. Design And Construction Of 300W Audio Power Amplifier For Classroom

    Directory of Open Access Journals (Sweden)

    Shune Lei Aung

    2015-07-01

    Full Text Available Abstract This paper describes the design and construction of 300W audio power amplifier for classroom. In the construction of this amplifier microphone preamplifier tone preamplifier equalizer line amplifier output power amplifier and sound level indicator are included. The output power amplifier is designed as O.C.L system and constructed by using Class B among many types of amplifier classes. There are two types in O.C.L system quasi system and complementary system. Between them the complementary system is used in the construction of 300W audio power amplifier. The Multisim software is utilized for the construction of audio power amplifier.

  17. Phased array of high-power, coherent, monolithic flared amplifier master oscillator power amplifiers

    Science.gov (United States)

    Osinski, J. S.; Mehuys, D.; Welch, D. F.; Waarts, R. G.; Major, J. S., Jr.; Dzurko, K. M.; Lang, R. J.

    1995-01-01

    A monolithically integrated array of InGaAs/AlGaAs flared amplifiers driven by a single DBR laser through a power splitter network and individually addressed phase modulators is described. Phase adjustment of ≳2π per element by free-carrier effects is verified by monitoring the interference pattern of all four emitters, and typically requires <15 mA of current to obtain a 2π phase shift. Phase matching is achieved among all four diffraction-limited emitters at a pulsed output power of ≳5 W, and, combined with the proper external lensing, could therefore result in an ultranarrow, single-lobed far-field pattern whose width is determined by the extended aperture of the array.

  18. Full characterization of the amplified spontaneous emission from a diode-pumped high-power laser system.

    Science.gov (United States)

    Keppler, S; Hornung, M; Bödefeld, R; Sävert, A; Liebetrau, H; Hein, J; Kaluza, M C

    2014-05-01

    We present the first complete temporal and spatial characterization of the amplified spontaneous emission (ASE) of laser radiation generated by a diode-pumped high-power laser system. The ASE of the different amplifiers was measured independently from the main pulse and was characterized within a time window of -10ms ≤ t ≤ 10ms and an accuracy of up to 15fs around the main pulse. Furthermore, the focusability and the energy of the ASE from each amplifier was measured after recompression. Using our analysis method, the laser components, which need to be optimized for a further improvement of the laser contrast, can be identified. This will be essential for laser-matter interaction experiments requiring a minimized ASE intensity or fluence.

  19. 88 W 0.5 mJ femtosecond laser pulses from two coherently combined fiber amplifiers.

    Science.gov (United States)

    Seise, Enrico; Klenke, Arno; Breitkopf, Sven; Limpert, Jens; Tünnermann, Andreas

    2011-10-01

    The generation of 0.5 mJ femtosecond laser pulses by coherent combining of two high power high energy fiber chirped-pulse amplifiers is reported. The system is running at a repetition frequency of 175 kHz producing 88 W of average power after the compressor unit. Polarizing beam splitters have been used to realize an amplifying Mach-Zehnder interferometer, which has been stabilized with a Hänsch-Couillaud measurement system. The stabilized system possesses a measured residual rms phase difference fluctuation between the two branches as low as λ/70 rad at the maximum power level. The experiment proves that coherent addition of femtosecond fiber lasers can be efficiently and reliably performed at high B-integral and considerable thermal load in the individual amplifiers.

  20. Integrated cladding-pumped multicore few-mode erbium-doped fibre amplifier for space-division-multiplexed communications

    Science.gov (United States)

    Chen, H.; Jin, C.; Huang, B.; Fontaine, N. K.; Ryf, R.; Shang, K.; Grégoire, N.; Morency, S.; Essiambre, R.-J.; Li, G.; Messaddeq, Y.; Larochelle, S.

    2016-08-01

    Space-division multiplexing (SDM), whereby multiple spatial channels in multimode and multicore optical fibres are used to increase the total transmission capacity per fibre, is being investigated to avert a data capacity crunch and reduce the cost per transmitted bit. With the number of channels employed in SDM transmission experiments continuing to rise, there is a requirement for integrated SDM components that are scalable. Here, we demonstrate a cladding-pumped SDM erbium-doped fibre amplifier (EDFA) that consists of six uncoupled multimode erbium-doped cores. Each core supports three spatial modes, which enables the EDFA to amplify a total of 18 spatial channels (six cores × three modes) simultaneously with a single pump diode and a complexity similar to a single-mode EDFA. The amplifier delivers >20 dBm total output power per core and EDFA enables combined space-division and wavelength-division multiplexed transmission over multiple multimode fibre spans.