Application of local area networks to accelerator control systems at the Stanford Linear Accelerator
Fox, J.D.; Linstadt, E.; Melen, R.
1983-03-01T23:59:59.000Z
The history and current status of SLAC's SDLC networks for distributed accelerator control systems are discussed. These local area networks have been used for instrumentation and control of the linear accelerator. Network topologies, protocols, physical links, and logical interconnections are discussed for specific applications in distributed data acquisition and control system, computer networks and accelerator operations.
Application of local area networks to accelerator control systems at the Stanford linear accelerator
Fox, J.D.; Linstadt, E.; Melen, R.
1983-08-01T23:59:59.000Z
The history and current status of SLAC's SDLC networks for distributed accelerator control systems are discussed. These local area networks have been used for instrumentation and control of the linear accelerator. Network topologies, protocols, physical links, and logical interconnections are discussed for specific applications in distributed data acquisition and control systems, computer networks and accelerator operations.
Novel Approach to Linear Accelerator Superconducting Magnet System
Kashikhin, Vladimir; /Fermilab
2011-11-28T23:59:59.000Z
Superconducting Linear Accelerators include a superconducting magnet system for particle beam transportation that provides the beam focusing and steering. This system consists of a large number of quadrupole magnets and dipole correctors mounted inside or between cryomodules with SCRF cavities. Each magnet has current leads and powered from its own power supply. The paper proposes a novel approach to magnet powering based on using superconducting persistent current switches. A group of magnets is powered from the same power supply through the common, for the group of cryomodules, electrical bus and pair of current leads. Superconducting switches direct the current to the chosen magnet and close the circuit providing the magnet operation in a persistent current mode. Two persistent current switches were fabricated and tested. In the paper also presented the results of magnetic field simulations, decay time constants analysis, and a way of improving quadrupole magnetic center stability. Such approach substantially reduces the magnet system cost and increases the reliability.
Buttram, M.T.; Ginn, J.W.
1988-06-21T23:59:59.000Z
A linear induction accelerator includes a plurality of adder cavities arranged in a series and provided in a structure which is evacuated so that a vacuum inductance is provided between each adder cavity and the structure. An energy storage system for the adder cavities includes a pulsed current source and a respective plurality of bipolar converting networks connected thereto. The bipolar high-voltage, high-repetition-rate square pulse train sets and resets the cavities. 4 figs.
Cryogenic system for the MYRRHA superconducting linear accelerator
Chevalier, Nicolas R.; Junquera, Tomas [Accelerators and Cryogenic Systems, 86, rue de Paris, 91400 Orsay (France); Thermeau, Jean-Pierre [Institut de Physique Nucléaire, Université Paris Sud, 91400 Orsay (France); Romão, Luis Medeiros; Vandeplassche, Dirk [SCK-CEN, Boeretang 200, 2400 Mol (Belgium)
2014-01-29T23:59:59.000Z
SCK?CEN, the Belgian Nuclear Research Centre, is designing MYRRHA, a flexible fast spectrum research reactor (80 MW{sub th}), conceived as an accelerator driven system (ADS), able to operate in sub-critical and critical modes. It contains a continuous-wave (CW) superconducting (SC) proton accelerator of 600 MeV, a spallation target and a multiplying core with MOX fuel, cooled by liquid lead-bismuth (Pb-Bi). From 17 MeV onward, the SC accelerator will consist of 48 ?=0.36 spoke-loaded cavities (352 MHz), 34 ?=0.47 elliptical cavities (704 MHz) and 60 ?=0.65 elliptical cavities (704 MHz). We present an analysis of the thermal loads and of the optimal operating temperature of the cryogenic system. In particular, the low operating frequency of spoke cavities makes their operation in CW mode possible both at 4.2 K or at 2 K. Our analysis outlines the main factors that determine at what temperature the spoke cavities should be operated. We then present different cryogenic fluid distribution schemes, important characteristics (storage, transfer line, etc.) and the main challenges offered by MYRRHA in terms of cryogenics.
Phase and amplitude control system for Stanford Linear Accelerator
Yoo, S.J.
1983-09-26T23:59:59.000Z
The computer controlled phase and amplitude detection system measures the instantaneous phase and amplitude of a 1 micro-second 2856 MHz rf pulse at a 180 Hz rate. This will be used for phase feedback control, and also for phase and amplitude jitter measurement. The program, which was originally written by John Fox and Keith Jobe, has been modified to improve the function of the system. The software algorithms used in the measurement are described, as is the performance of the prototype phase and amplitude detector system.
Linear accelerator for radioisotope production
Hansborough, L.D.; Hamm, R.W.; Stovall, J.E.
1982-02-01T23:59:59.000Z
A 200- to 500-..mu..A source of 70- to 90-MeV protons would be a valuable asset to the nuclear medicine program. A linear accelerator (linac) can achieve this performance, and it can be extended to even higher energies and currents. Variable energy and current options are available. A 70-MeV linac is described, based on recent innovations in linear accelerator technology; it would be 27.3 m long and cost approx. $6 million. By operating the radio-frequency (rf) power system at a level necessary to produce a 500-..mu..A beam current, the cost of power deposited in the radioisotope-production target is comparable with existing cyclotrons. If the rf-power system is operated at full power, the same accelerator is capable of producing an 1140-..mu..A beam, and the cost per beam watt on the target is less than half that of comparable cyclotrons.
Cast dielectric composite linear accelerator
Sanders, David M. (Livermore, CA); Sampayan, Stephen (Manteca, CA); Slenes, Kirk (Albuquerque, NM); Stoller, H. M. (Albuquerque, NM)
2009-11-10T23:59:59.000Z
A linear accelerator having cast dielectric composite layers integrally formed with conductor electrodes in a solventless fabrication process, with the cast dielectric composite preferably having a nanoparticle filler in an organic polymer such as a thermosetting resin. By incorporating this cast dielectric composite the dielectric constant of critical insulating layers of the transmission lines of the accelerator are increased while simultaneously maintaining high dielectric strengths for the accelerator.
Seismic response of linear accelerators
Collette, C; Guinchard, M; Hauviller, C
2010-01-01T23:59:59.000Z
This paper is divided into two parts. The first part presents recent measurements of ground motion in the LHC tunnel at CERN. From these measurements, an update of the ground motion model currently used in accelerator simulations is presented. It contains new features like a model of the lateral motion and the technical noise. In the second part, it is shown how this model can be used to evaluate the seismic response of a linear accelerator in the frequency domain. Then, the approach is validated numerically on a regular lattice, taking the dynamic behavior of the machine alignment stage and the mechanical stabilization of the quadrupoles into account.
Ultra-high vacuum photoelectron linear accelerator
Yu, David U.L.; Luo, Yan
2013-07-16T23:59:59.000Z
An rf linear accelerator for producing an electron beam. The outer wall of the rf cavity of said linear accelerator being perforated to allow gas inside said rf cavity to flow to a pressure chamber surrounding said rf cavity and having means of ultra high vacuum pumping of the cathode of said rf linear accelerator. Said rf linear accelerator is used to accelerate polarized or unpolarized electrons produced by a photocathode, or to accelerate thermally heated electrons produced by a thermionic cathode, or to accelerate rf heated field emission electrons produced by a field emission cathode.
The Klynac: An Integrated Klystron and Linear Accelerator
Potter, J. M., Schwellenbach, D., Meidinger, A.
2012-08-07T23:59:59.000Z
The Klynac concept integrates an electron gun, a radio frequency (RF) power source, and a coupled-cavity linear accelerator into a single resonant system
Voltage regulation in linear induction accelerators
Parsons, William M. (Santa Fe, NM)
1992-01-01T23:59:59.000Z
Improvement in voltage regulation in a Linear Induction Accelerator wherein a varistor, such as a metal oxide varistor, is placed in parallel with the beam accelerating cavity and the magnetic core. The non-linear properties of the varistor result in a more stable voltage across the beam accelerating cavity than with a conventional compensating resistance.
Voltage regulation in linear induction accelerators
Parsons, W.M.
1992-12-29T23:59:59.000Z
Improvement in voltage regulation in a linear induction accelerator wherein a varistor, such as a metal oxide varistor, is placed in parallel with the beam accelerating cavity and the magnetic core is disclosed. The non-linear properties of the varistor result in a more stable voltage across the beam accelerating cavity than with a conventional compensating resistance. 4 figs.
Neal, R B
1956-01-01T23:59:59.000Z
The Stanford Mark III linear accelerator and speculations concerning the multi-Bev applications of electron linear accelerators
Terahertz-driven linear electron acceleration
Nanni, Emilio Alessandro; Ravi, Koustuban; Fallahi, Arya; Moriena, Gustavo; Miller, R J Dwayne; Kärtner, Franz X
2014-01-01T23:59:59.000Z
The cost, size and availability of electron accelerators is dominated by the achievable accelerating gradient. Conventional high-brightness radio-frequency (RF) accelerating structures operate with 30-50 MeV/m gradients. Electron accelerators driven with optical or infrared sources have demonstrated accelerating gradients orders of magnitude above that achievable with conventional RF structures. However, laser-driven electron accelerators require intense sources and suffer from low bunch charge, sub-micron tolerances and sub-femtosecond timing requirements due to the short wavelength of operation. Here, we demonstrate the first linear acceleration of electrons with keV energy gain using optically-generated terahertz (THz) pulses. THz-driven accelerating structures enable high-gradient electron accelerators with simple accelerating structures, high repetition rates and significant charge per bunch. Increasing the operational frequency of accelerators into the THz band allows for greatly increased accelerating ...
Drift tube suspension for high intensity linear accelerators
Liska, D.J.; Schamaun, R.G.; Clark, D.C.; Potter, R.C.; Frank, J.A.
1980-03-11T23:59:59.000Z
The disclosure relates to a drift tube suspension for high intensity linear accelerators. The system comprises a series of box-sections girders independently adjustably mounted on a linear accelerator. A plurality of drift tube holding stems are individually adjustably mounted on each girder.
Variable-energy drift-tube linear accelerator
Swenson, Donald A. (Los Alamos, NM); Boyd, Jr., Thomas J. (Los Alamos, NM); Potter, James M. (Los Alamos, NM); Stovall, James E. (Los Alamos, NM)
1984-01-01T23:59:59.000Z
A linear accelerator system includes a plurality of post-coupled drift-tubes wherein each post coupler is bistably positionable to either of two positions which result in different field distributions. With binary control over a plurality of post couplers, a significant accumlative effect in the resulting field distribution is achieved yielding a variable-energy drift-tube linear accelerator.
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Development of compact linear accelerator in KBSI
Yoon, Jang-Hee; Lee, Byoung-Seob; Choi, Seyong; Park, Jin Yong; Ok, Jung-Woo; Won, Mi-Sook [Busan Center, Korea Basic Science Institute, Busan 609-735 (Korea, Republic of)
2012-02-15T23:59:59.000Z
The compact linear accelerator using a 28 GHz ECRIS is under construction in KBSI, South Korea. The main capability of this facility is the production of fast neurons for the neutron radiography. The designing of a superconducting magnet, microwave transmission system, beam extraction, and plasma chamber of ECRIS were finished. The nominal axial design fields of the magnets are 3.6 T at injection and 2.2 T at extraction; the nominal radial design field strength at the plasma chamber wall is 2.1 T. We already installed 10 kW, 28 GHz gyrotron, and tested a microwave power from gyrotron using a dummy load. The current status will be discussed in this paper.
Radio frequency quadrupole resonator for linear accelerator
Moretti, Alfred (Downers Grove, IL)
1985-01-01T23:59:59.000Z
An RFQ resonator for a linear accelerator having a reduced level of interfering modes and producing a quadrupole mode for focusing, bunching and accelerating beams of heavy charged particles, with the construction being characterized by four elongated resonating rods within a cylinder with the rods being alternately shorted and open electrically to the shell at common ends of the rods to provide an LC parallel resonant circuit when activated by a magnetic field transverse to the longitudinal axis.
Linear Accelerator | Advanced Photon Source
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The Klynac: An integrated klystron and linear accelerator
Potter, James M. [JP Accelerator Works, Inc., 2245 47th Street, Los Alamos NM 87544 (United States); Schwellenbach, David; Meidinger, Alfred [National Security Technologies, LLC, Los Alamos Operations, P.O. Box 809, Los Alamos NM 87544 (United States)
2013-04-19T23:59:59.000Z
The Klynac concept integrates an electron gun, a radio frequency (RF) power source, and a coupled-cavity linear accelerator into a single resonant system. The klystron is essentially a conventional klystron structure with an input cavity, some number of intermediate cavities and an output cavity. The accelerator structure is, likewise, a conventional on-axis coupled structure. The uniqueness is the means of coupling the klystron output cavity to the accelerator. The coupler is a resonant coupler rather than an ordinary transmission line. The geometry of such a system need not be coaxial. However, if the klystron and accelerator are coaxial we can eliminate the need for a separate cathode for the accelerator by injecting some of the klystron beam into the accelerator. Such a device can be made cylindrical which is ideal for some applications.
The Klynac: An Integrated Klystron and Linear Accelerator
Potter, J. M. [JP Accelerator Works; Schwellenbach, D. [NSTec
2013-04-01T23:59:59.000Z
The Klynac concept integrates an electron gun, a radio frequency (RF) power source, and a coupled-cavity linear accelerator into a single resonant system. The klystron is essentially a conventional klystron structure with an input cavity, some number of intermediate cavities and an output cavity. The accelerator structure is, likewise, a conventional on-axis coupled structure. The uniqueness is the means of coupling the klystron output cavity to the accelerator. The coupler is a resonant coupler rather than an ordinary transmission line. The geometry of such a system need not be coaxial. However, if the klystron and accelerator are coaxial we can eliminate the need for a separate cathode for the accelerator by injecting some of the klystron beam into the accelerator. Such a device can be made cylindrical which is ideal for some applications.
STANFORD LINEAR ACCELERATOR CENTER DIRECTOR'S OFFICE
Wechsler, Risa H.
of these offices not listed here. PART 1: RESEARCH & DEVELOPMENT PROGRAM MANAGEMENT RECORDS R&D Program Management records document the basis for research and development program management decisions, direction, policiesSTANFORD LINEAR ACCELERATOR CENTER DIRECTOR'S OFFICE RECORDS CONTROL SCHEDULE SCOPE: This schedule
STANFORD LINEAR ACCELERATOR CENTER RECORDS CONTROL SCHEDULE
Wechsler, Risa H.
to project justification, staffing, initiation, or execution; project management plans, records managementSTANFORD LINEAR ACCELERATOR CENTER PEP-II RECORDS CONTROL SCHEDULE SCOPE: This schedule covers records of the PEP-II project, regardless of format (paper, electronic, magnetic, photographic, etc
Enhanced dielectric-wall linear accelerator
Sampayan, S.E.; Caporaso, G.J.; Kirbie, H.C.
1998-09-22T23:59:59.000Z
A dielectric-wall linear accelerator is enhanced by a high-voltage, fast e-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface. 6 figs.
Enhanced dielectric-wall linear accelerator
Sampayan, Stephen E. (Manteca, CA); Caporaso, George J. (Livermore, CA); Kirbie, Hugh C. (Dublin, CA)
1998-01-01T23:59:59.000Z
A dielectric-wall linear accelerator is enhanced by a high-voltage, fast e-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface.
Bernardin, J. D. (John D.); Ammerman, C. N. (Curtt N.); Hopkins, S. M. (Steve M.)
2002-01-01T23:59:59.000Z
The Spallation Neutron Source (SNS) is a facility being designed for scientific and industrial research and development. The SNS will generate and employ neutrons as a research tool in a variety of disciplines including biology, material science, superconductivity, chemistry, etc. The neutrons will be produced by bombarding a heavy metal target with a high-energy beam of protons, generated and accelerated with a linear particle accelerator, or linac. The low energy end of the linac consists of, in part, a multi-cell copper structure termed a coupled cavity linac (CCL). The CCL is responsible for accelerating the protons from an energy of 87 MeV, to 185 MeV. Acceleration of the charged protons is achieved by the use of large electrical field gradients established within specially designed contoured cavities of the CCL. While a large amount of the electrical energy is used to accelerate the protons, approximately 60-80% of this electrical energy is dissipated in the CCL's copper structure. To maintain an acceptable operating temperature, as well as minimize thermal stresses and maintain desired contours of the accelerator cavities, the electrical waste heat must be removed from the CCL structure. This is done using specially designed water cooling passages within the linac's copper structure. Cooling water is supplied to these cooling passages by a complex water cooling and temperature control system. This paper discusses the design, analysis, and testing of a water cooling system for a prototype CCL. First, the design concept and method of water temperature control is discussed. Second, the layout of the prototype water cooling system, including the selection of plumbing components, instrumentation, as well as controller hardware and software is presented. Next, the development of a numerical network model used to size the pump, heat exchanger, and plumbing equipment, is discussed. Finally, empirical pressure, flow rate, and temperature data from the prototype CCL water cooling tests are used to assess water cooling system performance and numerical modeling accuracy.
COLLIMATING TOUSCHEK PARTICLES IN AN ENERGY RECOVERY LINEAR ACCELERATOR
Hoffstaetter, Georg
COLLIMATING TOUSCHEK PARTICLES IN AN ENERGY RECOVERY LINEAR ACCELERATOR Michael P. Ehrlichman- tum would usually be inconsequential to the trajectory of the particles through the accelerator to longitudinal momentum significant to the trajec- tory of scattered particles through the accelerator
Radio frequency focused interdigital linear accelerator
Swenson, Donald A.; Starling, W. Joel
2006-08-29T23:59:59.000Z
An interdigital (Wideroe) linear accelerator employing drift tubes, and associated support stems that couple to both the longitudinal and support stem electromagnetic fields of the linac, creating rf quadrupole fields along the axis of the linac to provide transverse focusing for the particle beam. Each drift tube comprises two separate electrodes operating at different electrical potentials as determined by cavity rf fields. Each electrode supports two fingers, pointing towards the opposite end of the drift tube, forming a four-finger geometry that produces an rf quadrupole field distribution along its axis. The fundamental periodicity of the structure is equal to one half of the particle wavelength .beta..lamda., where .beta. is the particle velocity in units of the velocity of light and .lamda. is the free space wavelength of the rf. Particles are accelerated in the gaps between drift tubes. The particle beam is focused in regions inside the drift tubes.
Linear induction accelerator and pulse forming networks therefor
Buttram, Malcolm T. (Sandia Park, NM); Ginn, Jerry W. (Albuquerque, NM)
1989-01-01T23:59:59.000Z
A linear induction accelerator includes a plurality of adder cavities arranged in a series and provided in a structure which is evacuated so that a vacuum inductance is provided between each adder cavity and the structure. An energy storage system for the adder cavities includes a pulsed current source and a respective plurality of bipolar converting networks connected thereto. The bipolar high-voltage, high-repetition-rate square pulse train sets and resets the cavities.
High-gradient compact linear accelerator
Carder, B.M.
1998-05-26T23:59:59.000Z
A high-gradient linear accelerator comprises a solid-state stack in a vacuum of five sets of disc-shaped Blumlein modules each having a center hole through which particles are sequentially accelerated. Each Blumlein module is a sandwich of two outer conductive plates that bracket an inner conductive plate positioned between two dielectric plates with different thicknesses and dielectric constants. A third dielectric core in the shape of a hollow cylinder forms a casing down the series of center holes, and it has a dielectric constant different that the two dielectric plates that sandwich the inner conductive plate. In operation, all the inner conductive plates are charged to the same DC potential relative to the outer conductive plates. Next, all the inner conductive plates are simultaneously shorted to the outer conductive plates at the outer diameters. The signal short will propagate to the inner diameters at two different rates in each Blumlein module. A faster wave propagates quicker to the third dielectric core across the dielectric plates with the closer spacing and lower dielectric constant. When the faster wave reaches the inner extents of the outer and inner conductive plates, it reflects back outward and reverses the field in that segment of the dielectric core. All the field segments in the dielectric core are then in unipolar agreement until the slower wave finally propagates to the third dielectric core across the dielectric plates with the wider spacing and higher dielectric constant. During such unipolar agreement, particles in the core are accelerated with gradients that exceed twenty megavolts per meter. 10 figs.
A Novel Approach to Non linear Shock Acceleration
Pasquale Blasi
2001-11-28T23:59:59.000Z
First order Fermi acceleration at astrophysical shocks is often invoked as a mechanism for the generation of non-thermal particles. This mechanism is especially simple in the approximation that the accelerated particles behave like test particles, not affecting the shocked fluid. Many complications enter the calculations when the accelerated particles have a backreaction on the fluid, in which case we may enter the non linear regime of shock acceleration. In this paper we summarize the main features of a semi-analytical approach to the study of the non linearity in shock acceleration, and compare some of the results with previous attempts and with the output of numerical simulations.
Transforming A Linear Algebra Core to An FFT Accelerator
Batory, Don
Transforming A Linear Algebra Core to An FFT Accelerator Ardavan Pedram, John McCalpin, Andreas the modifications required to transform a highly-efficient, specialized linear algebra core into an efficient engine computations and propose extensions to the micro-architecture of the baseline linear algebra core. Along
A Novel Linear Accelerator For Image Guided Radiation Therapy
Ding Xiaodong; Boucher, Salime [RadiaBeam Technologies, 1717 Stewart St., Santa Monica, CA 90404 (United States)
2011-06-01T23:59:59.000Z
RadiaBeam is developing a novel linear accelerator which produces both kilovoltage ({approx}100 keV) X-rays for imaging, and megavoltage (6 to 20 MeV) X-rays for therapy. We call this system the DEXITron: Dual Energy X-ray source for Imaging and Therapy. The Dexitron is enabled by an innovation in the electromagnetic design of the linac, which allows the output energy to be rapidly switched from high energy to low energy. In brief, the method involves switching the phase of the radiofrequency (RF) power by 180 degrees at some point in the linac such that, after that point, the linac decelerates the beam, rather than accelerating it. The Dexitron will have comparable cost to other linacs, and avoids the problems associated with current IGRT equipment.
A brief history of high power RF proton linear accelerators
Browne, J.C.
1996-12-31T23:59:59.000Z
The first mention of linear acceleration was in a paper by G. Ising in 1924 in which he postulated the acceleration of positive ions induced by spark discharges which produced electric fields in gaps between a series of {open_quotes}drift tubes{close_quotes}. Ising apparently was not able to demonstrate his concept, most likely due to the limited state of electronic devices. Ising`s work was followed by a seminal paper by R. Wideroe in 1928 in which he demonstrated the first linear accelerator. Wideroe was able to accelerate sodium or potassium ions to 50 keV of energy using drift tubes connected alternately to high frequency waves and to ground. Nuclear physics during this period was interested in accelerating protons, deuterons, electrons and alpha particles and not heavy ions like sodium or potassium. To accelerate the light ions required much higher frequencies than available at that time. So linear accelerators were not pursued heavily at that time. Research continued during the 1930s but the development of high frequency RF tubes for radar applications in World War 2 opened the potential for RF linear accelerators after the war. The Berkeley laboratory of E. 0. Lawrence under the leadership of Luis Alvarez developed a new linear proton accelerator concept that utilized drift tubes that required a full RF period to pass through as compared to the earlier concepts. This development resulted in the historic Berkeley 32 MeV proton linear accelerator which incorporated the {open_quotes}Alvarez drift tube{close_quotes} as the basic acceleration scheme using surplus 200 MHz radar components.
Bolie, V.W.
1990-07-03T23:59:59.000Z
A cooling system is provided for maintaining a preselected operating temperature in a device, which may be an RFQ accelerator, having a variable heat removal requirement, by circulating a cooling fluid through a cooling system remote from the device. Internal sensors in the device enable an estimated error signal to be generated from parameters which are indicative of the heat removal requirement from the device. Sensors are provided at predetermined locations in the cooling system for outputting operational temperature signals. Analog and digital computers define a control signal functionally related to the temperature signals and the estimated error signal, where the control signal is defined effective to return the device to the preselected operating temperature in a stable manner. The cooling system includes a first heat sink responsive to a first portion of the control signal to remove heat from a major portion of the circulating fluid. A second heat sink is responsive to a second portion of the control signal to remove heat from a minor portion of the circulating fluid. The cooled major and minor portions of the circulating fluid are mixed in response to a mixing portion of the control signal, which is effective to proportion the major and minor portions of the circulating fluid to establish a mixed fluid temperature which is effective to define the preselected operating temperature for the remote device. In an RFQ environment the stable temperature control enables the resonant frequency of the device to be maintained at substantially a predetermined value during transient operations. 3 figs.
Radio-frequency quadrupole resonator for linear accelerator
Moretti, A.
1982-10-19T23:59:59.000Z
An RFQ resonator for a linear accelerator having a reduced level of interfering modes and producing a quadrupole mode for focusing, bunching and accelerating beams of heavy charged particles, with the construction being characterized by four elongated resonating rods within a cylinder with the rods being alternately shorted and open electrically to the shell at common ends of the rods to provide an LC parallel resonant circuit when activated by a magnetic field transverse to the longitudinal axis.
Yu, S.
2008-01-01T23:59:59.000Z
Study of the Relativistic Klystron Two-Beam AcceleratorYu, S. S. , "Relativistic Klystron Two-Beam Accelerator,"S. , et al. , "Relativistic Klystron Two-Beam Accelerator As
Status of the Advanced Photon Source (APS) linear accelerator
White, M.; Berg, W.; Fuja, R.; Grelick, A.; Mavrogenes, G.; Nassiri, A.; Russell, T.; Wesolowski, W.
1993-08-01T23:59:59.000Z
A 2856-MHz S-band, 450-MeV electron/positron linear accelerator is the first part of the injector for the Advanced Photon Source (APS) 7-GeV storage ring. Construction of the APS linac is currently nearing completion, and commissioning will begin in July 1993. The linac and its current status are discussed in this paper.
STANFORD LINEAR ACCELERATOR CENTER Winter 1999, Vol. 29, No. 3
California at Santa Cruz, University of
STANFORD LINEAR ACCELERATOR CENTER Winter 1999, Vol. 29, No. 3 #12;The Beam Line is published GEORGE TRILLING, KARL VAN BIBBER HERMAN WINICK Illustrations TERRY ANDERSON Distribution CRYSTAL TILGHMAN A PERIODICAL OF PARTICLE PHYSICS WINTER 1999 VOL. 29, NUMBER 3 Printed on recycled paper FEATURES 2 GOLDEN
Yu, S.
2008-01-01T23:59:59.000Z
Study of the Relativistic Klystron Two- Beam AcceleratorProceedings Relativistic-Klystron Two-Beam-Accelerator as a76SF00098 RELATIVISTIC- KLYSTRON TWO-REAM-ACCELERATOR AS A
Finite element analyses of a linear-accelerator electron gun
Iqbal, M., E-mail: muniqbal.chep@pu.edu.pk, E-mail: muniqbal@ihep.ac.cn [Centre for High Energy Physics, University of the Punjab, Lahore 45590 (Pakistan); Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Wasy, A. [Department of Mechanical Engineering, Changwon National University, Changwon 641773 (Korea, Republic of)] [Department of Mechanical Engineering, Changwon National University, Changwon 641773 (Korea, Republic of); Islam, G. U. [Centre for High Energy Physics, University of the Punjab, Lahore 45590 (Pakistan)] [Centre for High Energy Physics, University of the Punjab, Lahore 45590 (Pakistan); Zhou, Z. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)] [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)
2014-02-15T23:59:59.000Z
Thermo-structural analyses of the Beijing Electron-Positron Collider (BEPCII) linear-accelerator, electron gun, were performed for the gun operating with the cathode at 1000?°C. The gun was modeled in computer aided three-dimensional interactive application for finite element analyses through ANSYS workbench. This was followed by simulations using the SLAC electron beam trajectory program EGUN for beam optics analyses. The simulations were compared with experimental results of the assembly to verify its beam parameters under the same boundary conditions. Simulation and test results were found to be in good agreement and hence confirmed the design parameters under the defined operating temperature. The gun is operating continuously since commissioning without any thermal induced failures for the BEPCII linear accelerator.
Beam dynamics in a long-pulse linear induction accelerator
Ekdahl, Carl [Los Alamos National Laboratory; Abeyta, Epifanio O [Los Alamos National Laboratory; Aragon, Paul [Los Alamos National Laboratory; Archuleta, Rita [Los Alamos National Laboratory; Cook, Gerald [Los Alamos National Laboratory; Dalmas, Dale [Los Alamos National Laboratory; Esquibel, Kevin [Los Alamos National Laboratory; Gallegos, Robert A [Los Alamos National Laboratory; Garnett, Robert [Los Alamos National Laboratory; Harrison, James F [Los Alamos National Laboratory; Johnson, Jeffrey B [Los Alamos National Laboratory; Jacquez, Edward B [Los Alamos National Laboratory; Mc Cuistian, Brian T [Los Alamos National Laboratory; Montoya, Nicholas A [Los Alamos National Laboratory; Nath, Subrato [Los Alamos National Laboratory; Nielsen, Kurt [Los Alamos National Laboratory; Oro, David [Los Alamos National Laboratory; Prichard, Benjamin [Los Alamos National Laboratory; Rose, Chris R [Los Alamos National Laboratory; Sanchez, Manolito [Los Alamos National Laboratory; Schauer, Martin M [Los Alamos National Laboratory; Seitz, Gerald [Los Alamos National Laboratory; Schulze, Martin [Los Alamos National Laboratory; Bender, Howard A [Los Alamos National Laboratory; Broste, William B [Los Alamos National Laboratory; Carlson, Carl A [Los Alamos National Laboratory; Frayer, Daniel K [Los Alamos National Laboratory; Johnson, Douglas E [Los Alamos National Laboratory; Tom, C Y [Los Alamos National Laboratory; Trainham, C [Los Alamos National Laboratory; Williams, John [Los Alamos National Laboratory; Scarpetti, Raymond [LLNL; Genoni, Thomas [VOSS; Hughes, Thomas [VOSS; Toma, Carsten [VOSS
2010-01-01T23:59:59.000Z
The second axis of the Dual Axis Radiography of Hydrodynamic Testing (DARHT) facility produces up to four radiographs within an interval of 1.6 microseconds. It accomplishes this by slicing four micro-pulses out of a long 1.8-kA, 16.5-MeV electron beam pulse and focusing them onto a bremsstrahlung converter target. The long beam pulse is created by a dispenser cathode diode and accelerated by the unique DARHT Axis-II linear induction accelerator (LIA). Beam motion in the accelerator would be a problem for radiography. High frequency motion, such as from beam breakup instability, would blur the individual spots. Low frequency motion, such as produced by pulsed power variation, would produce spot to spot differences. In this article, we describe these sources of beam motion, and the measures we have taken to minimize it.
Wave functions of linear systems
Tomasz Sowinski
2007-06-05T23:59:59.000Z
Complete analysis of quantum wave functions of linear systems in an arbitrary number of dimensions is given. It is shown how one can construct a complete set of stationary quantum states of an arbitrary linear system from purely classical arguments. This construction is possible because for linear systems classical dynamics carries the whole information about quantum dynamics.
Accelerated Iterative Method for Solving Steady Solutions of Linearized Atmospheric Models
Watanabe, Masahiro
Accelerated Iterative Method for Solving Steady Solutions of Linearized Atmospheric Models Masahiro approach, referred to as the accelerated iterative method (AIM), is developed for solving steady state, respectively. For ensuring the accelerated asymptotic convergence of iterative procedure
Beam-turning magnet design and test for the Recirculating Linear Accelerator
Crow, J.T. (Sandia National Labs., Albuquerque, NM (United States)); Platt, R.C. (Science Applications International Corp., San Diego, CA (United States))
1991-01-01T23:59:59.000Z
We have designed and tested a system for applying a ramped vertical magnetic field for turning the electron beam in the IFR Recirculating Linear Accelerator. The field is highly uniform over two Gaussian beam radii, and can be adjusted for a large radial gradient for increased energy bandwidth. The system includes shielding of the current-carrying rods to protect the pulser from REB induced fields and to reduce the effect of REB images on the beam transport to negligible levels. The system has been tested on the IBEX accelerator with > 95% peak current transport and > 90% charge transport through a 90{degree} turn. 2 refs., 6 figs.
Linear particle accelerator with seal structure between electrodes and insulators
Broadhurst, John H. (Golden Valley, MN)
1989-01-01T23:59:59.000Z
An electrostatic linear accelerator includes an electrode stack comprised of primary electrodes formed or Kovar and supported by annular glass insulators having the same thermal expansion rate as the electrodes. Each glass insulator is provided with a pair of fused-in Kovar ring inserts which are bonded to the electrodes. Each electrode is designed to define a concavo-convex particle trap so that secondary charged particles generated within the accelerated beam area cannot reach the inner surface of an insulator. Each insulator has a generated inner surface profile which is so configured that the electrical field at this surface contains no significant tangential component. A spark gap trigger assembly is provided, which energizes spark gaps protecting the electrodes affected by over voltage to prevent excessive energy dissipation in the electrode stack.
RECENT PROGRESS TOWARD A MUON RECIRCULATING LINEAR ACCELERATOR
Slawomir Bogacz, Vasiliy Morozov, Yves Roblin, Kevin Beard
2012-07-01T23:59:59.000Z
Both Neutrino Factories (NF) and Muon Colliders (MC) require very rapid acceleration due to the short lifetime of muons. After a capture and bunching section, a linac raises the energy to about 900 MeV, and is followed by one or more Recirculating Linear Accelerators (RLA), possibly followed by a Rapid Cycling Synchnotron (RCS) or Fixed-Field Alternating Gradient (FFAG) ring. A RLA reuses the expensive RF linac section for a number of passes at the price of having to deal with different energies within the same linac. Various techniques including pulsed focusing quadruopoles, beta frequency beating, and multipass arcs have been investigated via simulations to improve the performance and reduce the cost of such RLAs.
End-to-end absolute energy calibration of atmospheric fluorescence telescopes by an electron linear of fluorescence telescopes by using air showers induced by electron beams from a linear accelerator, which and constructing a compact linear accelerator with a maximum electron energy of 40 MeV and an intensity of 6.4 m
A threshold for laser-driven linear particle acceleration in unbounded vacuum
Wong, Liang Jie
2011-01-01T23:59:59.000Z
We hypothesize that a charged particle in unbounded vacuum can be substantially accelerated by a force linear in the electric field of a propagating electromagnetic wave only if the accelerating field is capable of bringing ...
Cryogen free superconducting splittable quadrupole magnet for linear accelerators
Kashikhin, V.S.; Andreev, N.; Kerby, J.; Orlov, Y.; Solyak, N.; Tartaglia, M.; Velev, G.; /Fermilab
2011-09-01T23:59:59.000Z
A new superconducting quadrupole magnet for linear accelerators was fabricated at Fermilab. The magnet is designed to work inside a cryomodule in the space between SCRF cavities. SCRF cavities must be installed inside a very clean room adding issues to the magnet design, and fabrication. The designed magnet has a splittable along the vertical plane configuration and could be installed outside of the clean room around the beam pipe previously connected to neighboring cavities. For more convenient assembly and replacement a 'superferric' magnet configuration with four racetrack type coils was chosen. The magnet does not have a helium vessel and is conductively cooled from the cryomodule LHe supply pipe and a helium gas return pipe. The quadrupole generates 36 T integrated magnetic field gradient, has 600 mm effective length, and the peak gradient is 54 T/m. In this paper the quadrupole magnetic, mechanical, and thermal designs are presented, along with the magnet fabrication overview and first test results.
2011 Annual Planning Summary for Stanford Linear Accelerator Center Site Office (SLAC)
Broader source: Energy.gov [DOE]
The ongoing and projected Environmental Assessments and Environmental Impact Statements for 2011 and 2012 within the Stanford Linear Accelerator Center Site Office (SLAC SO) (See also Science).
Stochastic bridges of linear systems
Yongxin Chen; Tryphon Georgiou
2014-07-12T23:59:59.000Z
We study a generalization of the Brownian bridge as a stochastic process that models the position and velocity of inertial particles between the two end-points of a time interval. The particles experience random acceleration and are assumed to have known states at the boundary. Thus, the movement of the particles can be modeled as an Ornstein-Uhlenbeck process conditioned on position and velocity measurements at the two end-points. It is shown that optimal stochastic control provides a stochastic differential equation (SDE) that generates such a bridge as a degenerate diffusion process. Generalizations to higher order linear diffusions are considered.
Environmental Survey preliminary report, Stanford Linear Accelerator Center, Stanford, California
Not Available
1988-07-01T23:59:59.000Z
This report presents the preliminary findings from the first phase of the Survey of the US Department of Energy (DOE) Stanford Linear Accelerator Center (SLAC) at Stanford, California, conducted February 29 through March 4, 1988. The Survey is being conducted by an interdisciplinary team of environmental specialists, led and managed by the Office of Environment, Safety and Health's Office of Environmental Audit. Individual team components are being supplied by a private contractor. The objective of the Survey is to identify environmental problems and areas of environmental risk associated with the SLAC. The Survey covers all environmental media and all areas of environmental regulation and is being performed in accordance with the DOE Environmental Survey Manual. This phase of the Survey involves the review of existing site environmental data, observations of the operations at the SLAC, and interviews with site personnel. The Survey team is developing a Sampling and Analysis Plan to assist in further assessing certain of the environmental problems identified during its on-site activities. The Sampling and Analysis Plan will be executed by a DOE National Laboratory or a support contractor. When completed, the results will be incorporated into the Environmental Survey Interim Report for the SLAC facility. The Interim Report will reflect the final determinations of the SLAC Survey. 95 refs., 25 figs., 25 tabs.
Estimation of Radiation Protection Shielding for a EURISOL Linear Proton Accelerator
Thomas Otto, CERN
A linear accelerator for protons, based on superconducting radiofrequency technology, is envisaged as a driver accelerator for the isotope production targets in a future EURISOL facility. This note reports basic estimates of the required radiation protection shielding of such an accelerator.
Algorithms for Solving Linear Congruences and Systems of Linear Congruences
Florentin Smarandache
2007-02-16T23:59:59.000Z
In this article we determine several theorems and methods for solving linear congruences and systems of linear congruences, and we find the number of distinct solutions. Many examples of solving congruences are given.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
LABORATORY PHYSICS DEPARTMENT Effective: 04012004 Page 1 of 2 Subject: Accelerator Test Facility - Linear Accelerator General Systems Guide Prepared by: Michael Zarcone...
Modified Accelerated Cost-Recovery System (MACRS)
Broader source: Energy.gov [DOE]
Under the federal Modified Accelerated Cost-Recovery System (MACRS), businesses may recover investments in certain property through depreciation deductions. The MACRS establishes a set of class l...
Tuning the DARHT Axis-II linear induction accelerator focusing
Ekdahl, Carl A. [Los Alamos National Laboratory
2012-04-24T23:59:59.000Z
Flash radiography of large hydrodynamic experiments driven by high explosives is a well-known diagnostic technique in use at many laboratories, and the Dual-Axis Radiography for Hydrodynamic Testing (DARHT) facility at Los Alamos produces flash radiographs of large hydrodynamic experiments. Two linear induction accelerators (LIAs) make the bremsstrahlung radiographic source spots for orthogonal views of each test. The 2-kA, 20-MeV Axis-I LIA creates a single 60-ns radiography pulse. The 1.7-kA, 16.5-MeV Axis-II LIA creates up to four radiography pulses by kicking them out of a longer pulse that has a 1.6-{mu}s flattop. The Axis-II injector, LIA, kicker, and downstream transport (DST) to the bremsstrahlung converter are described. Adjusting the magnetic focusing and steering elements to optimize the electron-beam transport through an LIA is often called 'tuning.' As in all high-current LIAs, the focusing field is designed to be as close to that of the ideal continuous solenoid as physically possible. In ideal continuous solenoidal transport a smoothly varying beam size can easily be found for which radial forces balance, and the beam is said to be 'matched' to the focusing field. A 'mismatched' beam exhibits unwanted oscillations in size, which are a source of free energy that contributes to emittance growth. This is undesirable, because in the absence of beam-target effects, the radiographic spot size is proportional to the emittance. Tuning the Axis-II LIA is done in two steps. First, the solenoidal focusing elements are set to values designed to provide a matched beam with little or no envelope oscillations, and little or no beam-breakup (BBU) instability growth. Then, steering elements are adjusted to minimize the motion of the centroid of a well-centered beam at the LIA exit. This article only describes the design of the tune for the focusing solenoids. The DARHT Axis-II LIA was required to be re-tuned after installing an accelerator cell to replace a failed solenoid in March of 2012. We took advantage of this opportunity to improve the design of the focusing tune with better models of the remaining partially failed solenoids, better estimates of beam initial conditions, and better values for pulsed-power voltages. As with all previous tunes for Axis-II, this one incorporates measures to mitigate beam-breakup (BBU) instability, image displacement instability (IDI), corkscrew (sweep), and emittance growth. Section II covers the general approach to of design of focusing solenoid tunes for the DARHT Axis-2 LIA. Section III explains the specific requirements and simulations needed to design the tune for the injector, which includes the thermionic electron source, diode, and six induction cells. Section IV explains the requirements and simulations for tuning the main accelerator, which consists of 68 induction cells. Finally, Section V explores sensitivity of the tune to deviations of parameters from nominal, random variations, and uncertainties in values. Four appendices list solenoid settings for this new tune, discuss comparisons of different simulation codes, show halo formation in mismatched beams, and present a brief discussion of the beam envelope equation, which is the heart of the method used to design LIA solenoid tunes.
A superconducting focusing solenoid for the neutrino factory linear accelerator
Green, Michael A.; Lebedev, V.; Strauss, B.P.
2001-01-01T23:59:59.000Z
et al, “The Role of Superconductivity and Cryogenics in theA Superconducting Focusing Solenoid for the Neutrino FactoryAcceleration Cells for the Superconducting Linac. Shown in
Design of a MeV, 4kA linear induction accelerator for flash radiography
Kulke, B.; Brier, R.; Chapin, W.
1981-02-10T23:59:59.000Z
For verifying the hydrodynamics of nuclear weapons design it is useful to have flash x-ray machines that can deliver a maximum dose in a minimum pulse length and with very high reliability. At LLNL, such a requirement was identified some years ago as 500 roentgens at one meter, in a 60 nsec pulse length. In response to this requirement, a linear induction accelerator was proposed to and funded by DOE in 1977. The design of this machine, called FXR, has now been completed and construction has begun. The FXR design extends the parameters of a similar machine that had been built and operated at LBL, Berkeley, some ten years ago. Using a cold cathode injector followed by 48 accelerator modules rated at 400 kV each, the FXR machine will accelerate a 4 kA electron beam pulse to 20 MeV final energy. Key design features are the generation and the stable transport of a low emittance (100 mr-cm) beam from a field emitter diode, the design of reliable, compact energy storage components such as Blumleins, feedlines and accelerator modules, and a computer-assisted control system.
Reiser, M
1973-01-01T23:59:59.000Z
Equilibrium Orbit And Linear Oscillations Of Charged particles In axisymmetric E X B Fields And Application To Electron Ring accelerator
Alsmiller, R G Jr; Lewis, T A
1985-01-01T23:59:59.000Z
Calculations Pertaining to the Design ofa Prebuncher fora 150-MeV electron Linear Accelerator. 3. Comparisons with Experimental Data
Zelinsky, A Y
2008-01-01T23:59:59.000Z
Transportation Channel with Uniform Electron Distribution for the Kharkov Neutron Source based on Subcritical Assembly Driven with Linear Accelerator
Simonov, K G; Mamontov, A V
2008-01-01T23:59:59.000Z
20 MW Pulse Amplifier Klystron with Multiple Frequency Two-Gap Bunching Resonators for Linear Electron Accelerators
Solar system constraints on Rindler acceleration
Sante Carloni; Daniel Grumiller; Florian Preis
2011-05-09T23:59:59.000Z
We discuss the classical tests of general relativity in the presence of Rindler acceleration. Among these tests the perihelion shifts give the tightest constraints and indicate that the Pioneer anomaly cannot be caused by a universal solar system Rindler acceleration. We address potential caveats for massive test-objects. Our tightest bound on Rindler acceleration that comes with no caveats is derived from radar echo delay and yields |a|<3nm/s^2.
Identifying Redundant Linear Constraints in Systems of Linear ...
2006-06-22T23:59:59.000Z
Jun 22, 2006 ... redundant linear constraints from the system (2.1) and (2.2). ... It is informative to note that in the above theorem, the optimal ..... S. Boyd and L. El Ghaoui, “Linear Matrix Inequalities in System and Control Theory”, SIAM, vol.
Wang, Yan Alexander
2011-01-01T23:59:59.000Z
THE JOURNAL OF CHEMICAL PHYSICS 134, 241103 (2011) Communication: Linear-expansion shooting techniques for accelerating self-consistent field convergence Yan Alexander Wang,1,a) Chi Yung Yam,2 Ya Kun), to accelerate the convergence of self-consistent field (SCF) calculations. Case studies show that overall LISTi
Photoelectron linear accelerator for producing a low emittance polarized electron beam
Yu, David U.; Clendenin, James E.; Kirby, Robert E.
2004-06-01T23:59:59.000Z
A photoelectron linear accelerator for producing a low emittance polarized electric beam. The accelerator includes a tube having an inner wall, the inner tube wall being coated by a getter material. A portable, or demountable, cathode plug is mounted within said tube, the surface of said cathode having a semiconductor material formed thereon.
A dosimetric characterization of a novel linear accelerator collimator
Thompson, C. M.; Weston, S. J., E-mail: steve.weston@leedsth.nhs.uk; Cosgrove, V. C. [Leeds Cancer Centre, Bexley Wing, St. James’ University Hospital, Leeds LS9 7TF (United Kingdom)] [Leeds Cancer Centre, Bexley Wing, St. James’ University Hospital, Leeds LS9 7TF (United Kingdom); Thwaites, D. I. [Institute of Medical Physics, School of Physics, University of Sydney, Sydney NSW 2006, Australia and Division of Medical Physics, Leeds Institute of Genetics, Health and Therapeutics, University of Leeds, Leeds LS2 9JT (United Kingdom)] [Institute of Medical Physics, School of Physics, University of Sydney, Sydney NSW 2006, Australia and Division of Medical Physics, Leeds Institute of Genetics, Health and Therapeutics, University of Leeds, Leeds LS2 9JT (United Kingdom)
2014-03-15T23:59:59.000Z
Purpose: The aim of this work is to characterize a new linear accelerator collimator which contains a single pair of sculpted diaphragms mounted orthogonally to a 160 leaf multileaf collimator (MLC). The diaphragms have “thick” regions providing full attenuation and “thin” regions where attenuation is provided by both the leaves and the diaphragm. The leaves are mounted on a dynamic leaf guide allowing rapid leaf motion and leaf travel over 350 mm. Methods: Dosimetric characterization, including assessment of leaf transmission, leaf tip transmission, penumbral width, was performed in a plotting tank. Head scatter factor was measured using a mini-phantom and the effect of leaf guide position on output was assessed using a water phantom. The tongue and groove effect was assessed using multiple exposures on radiochromic film. Leaf reproducibility was assessed from portal images of multiple abutting fields. Results: The maximum transmission through the multileaf collimator is 0.44% at 6 MV and 0.52% at 10 MV. This reduced to 0.22% and 0.27%, respectively, when the beam passes through the dynamic leaf guide in addition to the MLC. The maximum transmission through the thick part of the diaphragm is 0.32% and 0.36% at 6 and 10 MV. The combination of leaf and diaphragm transmission ranges from 0.08% to 0.010% at 6 MV and 0.10% to 0.14% depending on whether the shielding is through the thick or thin part of the diaphragm. The off-axis intertip transmission for a zero leaf gap is 2.2% at 6 and 10 MV. The leaf tip penumbra for a 100 × 100 mm field ranges from 5.4 to 4.3 mm at 6 and 10 MV across the full range of leaf motion when measured in the AB direction, which reduces to 4.0–3.4 mm at 6 MV and 4.5–3.8 mm at 10 MV when measured in the GT direction. For a 50 × 50?mm field, the diaphragm penumbra ranges from 4.3 to 3.7 mm at 6 MV and 4.5 to 4.1 mm at 10 MV in the AB direction and 3.7 to 3.2 mm at 6 MV and 4.2 to 3.7 mm when measured in the GT direction. The tongue and groove effect observed from exposure of a radiochromic film to two abutting fields is an underdose of 25%. The head scatter factor at both 6 and 10 MV is similar to that from the MLCi2 collimator to within 0.8%. The uncertainty in the leaf position reproducibility is 0.05 mm (2?). Conclusions: The Agility collimator is a low leakage, high definition collimator where both the MLC and the sculpted diaphragm have been optimized for dynamic treatments.
Proceedings of the Oak Ridge Electron Linear Accelerator (ORELA) Workshop
Dunn, M.E.
2006-02-27T23:59:59.000Z
The Oak Ridge National Laboratory (ORNL) organized a workshop at ORNL July 14-15, 2005, to highlight the unique measurement capabilities of the Oak Ridge Electron Linear Accelerator (ORELA) facility and to emphasize the important role of ORELA for performing differential cross-section measurements in the low-energy resonance region that is important for nuclear applications such as nuclear criticality safety, nuclear reactor and fuel cycle analysis, stockpile stewardship, weapons research, medical diagnosis, and nuclear astrophysics. The ORELA workshop (hereafter referred to as the Workshop) provided the opportunity to exchange ideas and information pertaining to nuclear cross-section measurements and their importance for nuclear applications from a variety of perspectives throughout the U.S. Department of Energy (DOE). Approximately 50 people, representing DOE, universities, and seven U.S. national laboratories, attended the Workshop. The objective of the Workshop was to emphasize the technical community endorsement for ORELA in meeting nuclear data challenges in the years to come. The Workshop further emphasized the need for a better understanding of the gaps in basic differential nuclear measurements and identified the efforts needed to return ORELA to a reliable functional measurement facility. To accomplish the Workshop objective, nuclear data experts from national laboratories and universities were invited to provide talks emphasizing the unique and vital role of the ORELA facility for addressing nuclear data needs. ORELA is operated on a full cost-recovery basis with no single sponsor providing complete base funding for the facility. Consequently, different programmatic sponsors benefit by receiving accurate cross-section data measurements at a reduced cost to their respective programs; however, leveraging support for a complex facility such as ORELA has a distinct disadvantage in that the programmatic funds are only used to support program-specific measurements. As a result, ORELA has not received base funding to support major upgrades and significant maintenance operations that are essential to keep the facility in a state of readiness over the long term. As a result, ORELA has operated on a ''sub-bare-minimum'' budget for the past 10 to 15 years, and the facility has not been maintained at a level for continued reliable operation for the long term. During the Workshop, Jerry McKamy (NNSA/NA-117) used a hospital patient metaphor that accurately depicts the facility status. ORELA is currently in the intensive care unit (ICU) on life support, and refurbishment efforts are needed to get the ''patient'' off life support and out to an ordinary hospital room. McKamy further noted that the DOE NCSP is planning to fund immediate refurbishment tasks ($1.5 M over three years) to help reestablish reliable ORELA operation (i.e., move ORELA from ICU to an ordinary hospital room). Furthermore, the NCSP will work to identify and carry out the actions needed to discharge ORELA from the ''hospital'' over the next five to seven years. In accordance with the Workshop objectives, the technical community publicly endorsed the need for a reliable ORELA facility that can meet current and future nuclear data needs. These Workshop proceedings provide the formal documentation of the technical community endorsement for ORELA. Furthermore, the proceedings highlight the past and current contributions that ORELA has made to the nuclear industry. The Workshop further emphasized the operational and funding problems that currently plague the facility, thereby limiting ORELA's operational reliability. Despite the recent operational problems, ORELA is a uniquely capable measurement facility that must be part of the overall U.S. nuclear data measurement portfolio in order to support current and emerging nuclear applications. The Workshop proceedings further emphasize that ORNL, the technical community, and programmatic sponsors are eager to see ORELA reestablish reliable measurement operation and be readily available to address nuclear data challe
Preliminary Safety Analysis Report (PSAR), The NSLS 200 MeV Linear Electron Accelerator
Blumberg, L.N.; Ackerman, A.I.; Dickinson, T.; Heese, R.N.; Larson, R.A.; Neuls, C.W.; Pjerov, S.; Sheehan, J.F.
1993-06-15T23:59:59.000Z
The radiological, fire and electrical hazards posed by a 200 MeV electron Linear Accelerator, which the NSLS Department will install and commission within a newly assembled structure, are addressed in this Preliminary Safety Analysis Report. Although it is clear that this accelerator is intended to be the injector for a future experimental facility, we address only the Linac in the present PSAR since neither the final design nor the operating characteristics of the experimental facility are known at the present time. The fire detection and control system to be installed in the building is judged to be completely adequate in terms of the marginal hazard presented - no combustible materials other than the usual cabling associated with such a facility have been identified. Likewise, electrical hazards associated with power supplies for the beam transport magnets and accelerator components such as the accelerator klystrons and electron gun are classified as marginal in terms of potential personnel injury, cost of equipment lost, program downtime and public impact perceptions as defined in the BNL Environmental Safety and Health Manual and the probability of occurrence is deemed to be remote. No unusual features have been identified for the power supplies or electrical distribution system, and normal and customary electrical safety standards as practiced throughout the NSLS complex and the Laboratory are specified in this report. The radiation safety hazards are similarly judged to be marginal in terms of probability of occurrence and potential injury consequences since, for the low intensity operation proposed - a factor of 25 less than the maximum Linac capability specified by the vendor - the average beam power is only 0.4 watts. The shielding specifications given in this report will give adequate protection to both the general public and nonradiation workers in areas adjacent to the building as well as radiation workers within the controlled access building.
Accelerating the transformation of power systems
Accelerating the transformation of power systems Introduction Flexibility of operation--the ability of a power system to respond to change in demand and supply--is a characteristic of all power systems. Flexibility is especially prized in twenty-first century power systems, with higher levels of grid
Non-perturbative aspects of particle acceleration in non-linear electrodynamics
David A. Burton; Stephen P. Flood; Haibao Wen
2015-04-20T23:59:59.000Z
We undertake an investigation of particle acceleration in the context of non-linear electrodynamics. We deduce the maximum energy that an electron can gain in a non-linear density wave in a magnetised plasma, and we show that an electron can `surf' a sufficiently intense Born-Infeld electromagnetic plane wave and be strongly accelerated by the wave. The first result is valid for a large class of physically reasonable modifications of the linear Maxwell equations, whilst the second result exploits the special mathematical structure of Born-Infeld theory.
Accelerating the transformation of power systems
Accelerating the transformation of power systems Ancillary Services Peer Exchange with India in power system transformation is an increasingly vital resource for national and subnational decision of power systems. The Power Partnership is a multilateral effort of the Clean Energy Ministerial and serves
Vehicle Systems Integration Laboratory Accelerates Powertrain Development
None
2014-04-15T23:59:59.000Z
ORNL's Vehicle Systems Integration (VSI) Laboratory accelerates the pace of powertrain development by performing prototype research and characterization of advanced systems and hardware components. The VSI Lab is capable of accommodating a range of platforms from advanced light-duty vehicles to hybridized Class 8 powertrains with the goals of improving overall system efficiency and reducing emissions.
Vehicle Systems Integration Laboratory Accelerates Powertrain Development
None
2014-06-25T23:59:59.000Z
ORNL's Vehicle Systems Integration (VSI) Laboratory accelerates the pace of powertrain development by performing prototype research and characterization of advanced systems and hardware components. The VSI Lab is capable of accommodating a range of platforms from advanced light-duty vehicles to hybridized Class 8 powertrains with the goals of improving overall system efficiency and reducing emissions.
Superstructure for high current applications in superconducting linear accelerators
Sekutowicz, Jacek (Elbchaussee, DE); Kneisel, Peter (Williamsburg, VA)
2008-03-18T23:59:59.000Z
A superstructure for accelerating charged particles at relativistic speeds. The superstructure consists of two weakly coupled multi-cell subunits equipped with HOM couplers. A beam pipe connects the subunits and an HOM damper is included at the entrance and the exit of each of the subunits. A coupling device feeds rf power into the subunits. The subunits are constructed of niobium and maintained at cryogenic temperatures. The length of the beam pipe between the subunits is selected to provide synchronism between particles and rf fields in both subunits.
Lee, Hyunho; Jo, Yunhui; Yoon, Myonggeun
2015-01-01T23:59:59.000Z
Quality assurance (QA) for medical linear accelerators is indispensable for appropriate cancer treatment. Some international organizations and western advanced countries provide QA guidelines for linear accelerators. Currently, QA regulations for linear accelerators in Korean hospitals specify a system in which each hospital stipulates its independent hospital-based protocols for QA procedures (HP_QAPs) and conducts QA based on these HP_QAPs while regulatory authorities verify whether items under these HP_QAPs have been performed. However, because this regulatory method cannot guarantee the quality of universal treatment, and QA items with tolerance criteria are different in many hospitals, the presentation of standardized QA items and tolerance criteria is essential. In this study, QA items in HP_QAPs from various hospitals and those presented by international organizations. Concordance rates between QA items for linear accelerators that were presented by the aforementioned organizations and those currently ...
Application accelerator system having bunch control
Wang, Dunxiong (Newport News, VA); Krafft, Geoffrey Arthur (Newport News, VA)
1999-01-01T23:59:59.000Z
An application accelerator system for monitoring the gain of a free electron laser. Coherent Synchrotron Radiation (CSR) detection techniques are used with a bunch length monitor for ultra short, picosec to several tens of femtosec, electron bunches. The monitor employs an application accelerator, a coherent radiation production device, an optical or beam chopping device, an infrared radiation collection device, a narrow-banding filter, an infrared detection device, and a control.
Application accelerator system having bunch control
Wang, D.; Krafft, G.A.
1999-06-22T23:59:59.000Z
An application accelerator system for monitoring the gain of a free electron laser is disclosed. Coherent Synchrotron Radiation (CSR) detection techniques are used with a bunch length monitor for ultra short, picosec to several tens of femtosec, electron bunches. The monitor employs an application accelerator, a coherent radiation production device, an optical or beam chopping device, an infrared radiation collection device, a narrow-banding filter, an infrared detection device, and a control. 1 fig.
Optimal coupler and power setting for superconductive linear accelerators
Branlard, J.; Chase, B,; Nagaitsev, S.; Nezhevenko, O.; Reid, J.; /Fermilab
2008-09-01T23:59:59.000Z
The modeling analysis presented in this paper addresses the question of how to achieve the highest vector sum gradient for all beam currents when individual cavities operate at different gradients due to their inherent quenching limitations. The analytical method explained here constitutes a step forward toward the operability of the International Linear Collider (ILC), Project X [8], or XFEL [7]. Unlike previously proposed methods [1, 2], this approach prevents cavities from quenching should the beam current be lower than its maximum value.
Fermilab accelerator control system: Analog monitoring facilities
Seino, K.; Anderson, L.; Smedinghoff, J.
1987-10-01T23:59:59.000Z
Thousands of analog signals are monitored in different areas of the Fermilab accelerator complex. For general purposes, analog signals are sent over coaxial or twinaxial cables with varying lengths, collected at fan-in boxes and digitized with 12 bit multiplexed ADCs. For higher resolution requirements, analog signals are digitized at sources and are serially sent to the control system. This paper surveys ADC subsystems that are used with the accelerator control systems and discusses practical problems and solutions, and it describes how analog data are presented on the console system.
Generic device controller for accelerator control systems
Mariotti, R.; Buxton, W.; Frankel, R.; Hoff, L.
1987-01-01T23:59:59.000Z
A new distributed intelligence control system has become operational at the AGS for transport, injection, and acceleration of heavy ions. A brief description of the functionality of the physical devices making up the system is given. An attempt has been made to integrate the devices for accelerator specific interfacing into a standard microprocessor system, namely, the Universal Device Controller (UDC). The main goals for such a generic device controller are to provide: local computing power; flexibility to configure; and real time event handling. The UDC assemblies and software are described. (LEW)
System identification for passive linear quantum systems
Madalin Guta; Naoki Yamamoto
2014-08-27T23:59:59.000Z
System identification is a key enabling component for the implementation of quantum technologies, including quantum control. In this paper, we consider the class of passive linear input-output systems, and investigate several basic questions: (1) which parameters can be identified? (2) Given sufficient input-output data, how do we reconstruct system parameters? (3) How can we optimize the estimation precision by preparing appropriate input states and performing measurements on the output? We show that minimal systems can be identified up to a unitary transformation on the modes, and systems satisfying a Hamiltonian connectivity condition called "infecting" are completely identifiable. We propose a frequency domain design based on a Fisher information criterion, for optimizing the estimation precision for coherent input state. As a consequence of the unitarity of the transfer function, we show that the Heisenberg limit with respect to the input energy can be achieved using non-classical input states.
Muon Accelerator Program: Area System Concept
McDonald, Kirk
Muon Accelerator Program: Area System Concept Specification Area System: Front End MAP L2 Manager coil insert near the target. Radiation damage (particularly to organic insulators) limits the dose stored in the 20-T coils is about 3 GJ. The target will also suffer radiation damage and must be replaced
BNL ACCELERATOR TEST FACILITY CONTROL SYSTEM UPGRADE R. Malone...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
ACCELERATOR TEST FACILITY CONTROL SYSTEM UPGRADE R. Malone, I. Ben-Zvi, X. Wang, V. Yakimenko BNL , Upton, NY 11973, USA Abstract Brookhaven National Laboratory's Accelerator...
Superconducting magnets for SCRF cryomodules at front end of linear accelerators
Kashikhin, V.S.; Andreev, N.; Orlov, Y.; Orris, D.F.; Tartaglia, M.A.; /Fermilab
2010-05-01T23:59:59.000Z
Linear accelerators based on a superconducting technology need various superconducting magnets mounted inside SCRF Cryomodules. Relatively weak iron-dominated magnets are installed at the front end of linear accelerators. The focusing quadrupoles have integrated gradients in the range of 1-4 T, and apertures in the range 35-90 mm. Superconducting dipole correctors and quadrupoles were designed at Fermilab for various projects. In this paper these magnet designs, and test results of a fabricated dipole corrector, are presented. Also briefly discussed are magnetic and mechanical designs, quench protection, cooling, fabrication, and assembly into cryomodule.
Electron beam dynamics in the DARHT-II linear induction accelerator
Ekdahl, Carl A [Los Alamos National Laboratory; Abeyta, Epifanio O [Los Alamos National Laboratory; Aragon, Paul [Los Alamos National Laboratory; Archuleta, Rita [Los Alamos National Laboratory; Cook, Gerald [Los Alamos National Laboratory; Dalmas, Dale [Los Alamos National Laboratory; Esquibel, Kevin [Los Alamos National Laboratory; Gallegos, Robert A [Los Alamos National Laboratory; Garnett, Robert [Los Alamos National Laboratory; Harrison, James F [Los Alamos National Laboratory; Johnson, Jeffrey B [Los Alamos National Laboratory; Jacquez, Edward B [Los Alamos National Laboratory; Mccuistian, Brian T [Los Alamos National Laboratory; Montoya, Nicholas A [Los Alamos National Laboratory; Nath, Subrata [Los Alamos National Laboratory; Nielsen, Kurt [Los Alamos National Laboratory; Oro, David [Los Alamos National Laboratory; Prichard, Benjamin [Los Alamos National Laboratory; Rowton, Lawrence [Los Alamos National Laboratory; Sanchez, Manolito [Los Alamos National Laboratory; Scarpetti, Raymond [Los Alamos National Laboratory; Schauer, Martin M [Los Alamos National Laboratory; Seitz, Gerald [Los Alamos National Laboratory; Schulze, Martin [Los Alamos National Laboratory; Bender, Howard A [Los Alamos National Laboratory; Broste, William B [Los Alamos National Laboratory; Carlson, Carl A [Los Alamos National Laboratory; Frayer, Daniel K [Los Alamos National Laboratory; Johnson, Douglas E [Los Alamos National Laboratory; Tom, C Y [Los Alamos National Laboratory; Trainham, C [NSTEC/STL; Williams, John [Los Alamos National Laboratory; Genoni, Thomas [VOSS; Hughes, Thomas [VOSS; Toma, Carsten [VOSS
2008-01-01T23:59:59.000Z
The DARHT-II linear induction accelerator (LIA) accelerates a 2-kA electron beam to more than 17 MeV. The beam pulse has a greater than 1.5-microsecond flattop region over which the electron kinetic energy is constant to within 1%. The beam dynamics are diagnosed with 21 beam-position monitors located throughout the injector, accelerator, and after the accelerator exit, where we also have beam imaging diagnostics. We discuss the tuning of the injector and accelerator, and present data for the resulting beam dynamics. We discuss the tuning procedures and other methods used to minimize beam motion, which is undesirable for its application as a bremsstrahlung source for multi-pulse radiography of exlosively driven hydrodynamic experiments. We also present beam stability measurements, which we relate to previous stability experiments at lower current and energy.
Small system for tritium accelerator mass spectrometry
Roberts, Mark L. (Livermore, CA); Davis, Jay C. (Livermore, CA)
1993-01-01T23:59:59.000Z
Apparatus for ionizing and accelerating a sample containing isotopes of hydrogen and detecting the ratios of hydrogen isotopes contained in the sample is disclosed. An ion source generates a substantially linear ion beam including ions of tritium from the sample. A radio-frequency quadrupole accelerator is directly coupled to and axially aligned with the source at an angle of substantially zero degrees. The accelerator accelerates species of the sample having different mass to different energy levels along the same axis as the ion beam. A spectrometer is used to detect the concentration of tritium ions in the sample. In one form of the invention, an energy loss spectrometer is used which includes a foil to block the passage of hydrogen, deuterium and .sup.3 He ions, and a surface barrier or scintillation detector to detect the concentration of tritium ions. In another form of the invention, a combined momentum/energy loss spectrometer is used which includes a magnet to separate the ion beams, with Faraday cups to measure the hydrogen and deuterium and a surface barrier or scintillation detector for the tritium ions.
Small system for tritium accelerator mass spectrometry
Roberts, M.L.; Davis, J.C.
1993-02-23T23:59:59.000Z
Apparatus for ionizing and accelerating a sample containing isotopes of hydrogen and detecting the ratios of hydrogen isotopes contained in the sample is disclosed. An ion source generates a substantially linear ion beam including ions of tritium from the sample. A radio-frequency quadrupole accelerator is directly coupled to and axially aligned with the source at an angle of substantially zero degrees. The accelerator accelerates species of the sample having different mass to different energy levels along the same axis as the ion beam. A spectrometer is used to detect the concentration of tritium ions in the sample. In one form of the invention, an energy loss spectrometer is used which includes a foil to block the passage of hydrogen, deuterium and [sup 3]He ions, and a surface barrier or scintillation detector to detect the concentration of tritium ions. In another form of the invention, a combined momentum/energy loss spectrometer is used which includes a magnet to separate the ion beams, with Faraday cups to measure the hydrogen and deuterium and a surface barrier or scintillation detector for the tritium ions.
Ground test accelerator control system software
Burczyk, L.; Dalesio, R.; Dingler, R.; Hill, J.; Howell, J.A.; Kerstiens, D.; King, R.; Kozubal, A.; Little, C.; Martz, V.; Rothrock, R.; Sutton, J.
1988-01-01T23:59:59.000Z
The GTA control system provides an environment in which the automation of a state-of-the-art accelerator can be developed. It makes use of commercially available computers, workstations, computer networks, industrial I/O equipment, and software. This system has built-in supervisory control (like most accelerator control systems), tools to support continuous control (like the process control industry), and sequential control for automatic startup and fault recovery (like few other accelerator control systems). Several software tools support these levels of control: a real-time operating system (VxWorks) with a real-time kernel (VRTX), a configuration database, a sequencer, and a graphics editor. VxWorks supports multitasking, fast context-switching, and preemptive scheduling. VxWorks/VRTX is a network-based development environment specifically designed to work in partnership with the UNIX operating system. A database provides the interface to the accelerator components. It consists of a run time library and a database configuration and editing tool. A sequencer initiates and controls the operation of all sequence programs (expressed as state programs). A graphics editor gives the user the ability to create color graphic displays showing the state of the machine in either text or graphics form. 11 refs., 2 figs.
Haworth, M.D.; Platt, R.C.; Smith, D.L.,; Mazarakis, M.G.; Poukey, J.W.; Leifeste, G.T.; Hasti, D.E.; Bennett, L.F.; Lucero, S.J. (Science Applications International Corp., Albuquerque, NM (USA); Sandia National Labs., Albuquerque, NM (USA); Diversus, Inc., Albuquerque, NM (USA))
1989-01-01T23:59:59.000Z
Beam transport experiments on Sandia's Recirculating Linear Accelerator (RLA) using a 1.5-MV injector with and without an additional 1.0 MV of acceleration provided by the ET-2 accelerating cavity were concluded this year. Our experimental results show that an injected beam of only 1.5 MeV requires too large an f-value in the IFR channel to effectively propagate a 10-kA beam. Dramatic improvement in current transport was seen for the higher-{gamma} 2.5 MeV beam. Based on these results plus computer simulation results, the 4.0 MeV IBEX accelerator is now being used as the RLA injector. 10 refs., 7 figs.
Byer, Robert L.
Proposed structure for a crossed-laser beam, GeV per meter gradient, vacuum electron linear We propose a dielectric-based, multistaged, laser-driven electron linear accelerator structure operating in a vacuum that is capable of accelerating electrons to 1 TeV in 1 km. Our study shows that a Ge
2002-01-01T23:59:59.000Z
PHYSICAL REVIEW SPECIAL TOPICS - ACCELERATORS AND BEAMS, VOLUME 5, 011001 (2002) Energy doubler. Hogan, R. Iverson, and D. Walz Stanford Linear Accelerator Center, Stanford University, Stanford of microbunches with the first driving a plasma wake that accelerates the second. The luminosity of the doubled
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article) |govInstrumentsmfrirtA Journey Inside the Complex and PowerfulJosephCenterCenter (LMI-EFRC) - PaulChoices toLeeLinda
Hardware Accelerator for MIMO Wireless Systems
Bhagawat, Pankaj
2012-02-14T23:59:59.000Z
of DOCTOR OF PHILOSOPHY Approved by: Chair of Committee, Gwan Choi Committee Members, Jiang Hu Rabi Mahapatra Jim Ji Head of Department, Costas Georghiades December 2011 Major Subject: Computer Engineering iii ABSTRACT Hardware Accelerator for MIMO... Wireless Systems. (December 2011) Pankaj Bhagawat, B.S., National Insitute of Technology, Tiruchirapally, India; M.S., Texas A&M University Chair of Advisory Committee: Dr. Gwan Choi Ever increasing demand for higher data rates and better Quality...
The design of a simulated in-line side-coupled 6 MV linear accelerator waveguide
St Aubin, Joel; Steciw, Stephen; Fallone, B. G. [Department of Physics, University of Alberta, 11322-89 Avenue, Edmonton, Alberta T6G 2G7 (Canada) and Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada) and Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Department of Physics, University of Alberta, 11322-89 Avenue, Edmonton, Alberta T6G 2G7 (Canada); Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); and Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada)
2010-02-15T23:59:59.000Z
Purpose: The design of a 3D in-line side-coupled 6 MV linac waveguide for medical use is given, and the effect of the side-coupling and port irises on the radio frequency (RF), beam dynamics, and dosimetric solutions is examined. This work was motivated by our research on a linac-MR hybrid system, where accurate electron trajectory information for a clinical medical waveguide in the presence of an external magnetic field was needed. Methods: For this work, the design of the linac waveguide was generated using the finite element method. The design outlined here incorporates the necessary geometric changes needed to incorporate a full-end accelerating cavity with a single-coupling iris, a waveguide-cavity coupling port iris that allows power transfer into the waveguide from the magnetron, as well as a method to control the RF field magnitude within the first half accelerating cavity into which the electrons from the gun are injected. Results: With the full waveguide designed to resonate at 2998.5{+-}0.1 MHz, a full 3D RF field solution was obtained. The accuracy of the 3D RF field solution was estimated through a comparison of important linac parameters (Q factor, shunt impedance, transit time factor, and resonant frequency) calculated for one accelerating cavity with the benchmarked program SUPERFISH. It was found that the maximum difference between the 3D solution and SUPERFISH was less than 0.03%. The eigenvalue solver, which determines the resonant frequencies of the 3D side-coupled waveguide simulation, was shown to be highly accurate through a comparison with lumped circuit theory. Two different waveguide geometries were examined, one incorporating a 0.5 mm first side cavity shift and another with a 1.5 mm first side cavity shift. The asymmetrically placed side-coupling irises and the port iris for both models were shown to introduce asymmetries in the RF field large enough to cause a peak shift and skewing (center of gravity minus peak shift) of an initially cylindrically uniform electron beam accelerating within the waveguide. The shifting and skewing of the electron beam were found to be greatest due to the effects of the side-coupling irises on the RF field. A further Monte Carlo study showed that this effect translated into a 1% asymmetry in a 40x40 cm{sup 2} field dose profile. Conclusions: A full 3D design for an in-line side-coupled 6 MV linear accelerator that emulates a common commercial waveguide has been given. The effect of the side coupling on the dose distribution has been shown to create a slight asymmetry, but overall does not affect the clinical applicability of the linac. The 3D in-line side-coupled linac model further provides a tool for the investigation of linac performance within an external magnetic field, which exists in an integrated linac-MR system.
Design and Factory Test of the E /E- Frascati Linear Accelerator for DAFNE
Anamkath, H.; Lyons, S.; Nett, D.; Treas, P.; Whitham, K.; Zante, T.; /Titan Beta, Dublin; Miller, R.; /Titan Beta, Dublin /SLAC; Boni, R.; Hsieh, H.; Sannibale, F.; Vescovi, M.; Vignola, G.; /Frascati
2011-11-28T23:59:59.000Z
The electron-positron accelerator for the DAFNE project has been built and is in test at Titan Beta in Dublin, CA. This S-Band RF linac system utilizes four 45 MW sledded klystrons and 16-3 m accelerating structures to achieve the required performance. It delivers a 4 ampere electron beam to the positron converter and accelerates the resulting positrons to 550 MeV. The converter design uses a 4.3T pulsed tapered flux compressor along with a pseudo-adiabatic tapered field to a 5 KG solenoid over the first two positron accelerating sections. Quadrupole focusing is used after 100 MeV. The system performance is given in Table 1. This paper briefly describes the design and development of the various subassemblies in this system and gives the initial factory test data.
Proceedings of the conference on computer codes and the linear accelerator community
Cooper, R.K. (comp.)
1990-07-01T23:59:59.000Z
The conference whose proceedings you are reading was envisioned as the second in a series, the first having been held in San Diego in January 1988. The intended participants were those people who are actively involved in writing and applying computer codes for the solution of problems related to the design and construction of linear accelerators. The first conference reviewed many of the codes both extant and under development. This second conference provided an opportunity to update the status of those codes, and to provide a forum in which emerging new 3D codes could be described and discussed. The afternoon poster session on the second day of the conference provided an opportunity for extended discussion. All in all, this conference was felt to be quite a useful interchange of ideas and developments in the field of 3D calculations, parallel computation, higher-order optics calculations, and code documentation and maintenance for the linear accelerator community. A third conference is planned.
Orbit correction in a linear nonscaling fixed field alternating gradient accelerator
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Kelliher, D. J.; Machida, S.; Edmonds, C. S.; Kirkman, I. W.; Jones, J. K.; Muratori, B. D.; Garland, J. M.; Berg, J. S.
2014-11-01T23:59:59.000Z
In a linear non-scaling FFAG the large natural chromaticity of the machine results in a betatron tune that varies by several integers over the momentum range. Orbit correction is complicated by the consequent variation of the phase advance between lattice elements. Here we investigate how the correction of multiple closed orbit harmonics allows correction of both the COD and the accelerated orbit distortion over the momentum range.
Kim, I Jong; Kim, Chul Min; Kim, Hyung Taek; Sung, Jae Hee; Lee, Seong Ku; Yu, Tae Jun; Choi, Il Woo; Lee, Chang-Lyoul; Nam, Kee Hwan; Nickles, Peter V; Jeong, Tae Moon; Lee, Jongmin
2013-01-01T23:59:59.000Z
Particle acceleration using ultraintense, ultrashort laser pulses is one of the most attractive topics in relativistic laser-plasma research. We report proton/ion acceleration in the intensity range of 5x1019 W/cm2 to 3.3x1020 W/cm2 by irradiating linearly polarized, 30-fs, 1-PW laser pulses on 10- to 100-nm-thick polymer targets. The proton energy scaling with respect to the intensity and target thickness was examined. The experiments demonstrated, for the first time with linearly polarized light, a transition from the target normal sheath acceleration to radiation pressure acceleration and showed a maximum proton energy of 45 MeV when a 10-nm-thick target was irradiated by a laser intensity of 3.3x1020 W/cm2. The experimental results were further supported by two- and three-dimensional particle-in-cell simulations. Based on the deduced proton energy scaling, proton beams having an energy of ~ 200 MeV should be feasible at a laser intensity of 1.5x1021 W/cm2.
Tower systems for Linearly repetitive Delone sets
José Aliste-Prieto; Daniel Coronel
2010-03-22T23:59:59.000Z
In this paper we study linearly repetitive Delone sets and prove, following the work of Bellissard, Benedetti and Gambaudo, that the hull of a linearly repetitive Delone set admits a properly nested sequence of box decompositions (tower system) with strictly positive and uniformly bounded (in size and norm) transition matrices. This generalizes a result of Durand for linearly recurrent symbolic systems. Furthermore, we apply this result to give a new proof of a classic estimation of Lagarias and Pleasants on the rate of convergence of patch-frequencies.
Danon, Yaron
Advances in Parametric X-Ray Production at the RPI Linear Accelerator B. Sones, Y. Danon, and R-ray source for practical applications such as medical imaging and material characterization. This phenomenon
Alain Blondel; Alex Chao; Weiren Chou; Jie Gao; Daniel Schulte; Kaoru Yokoya
2013-02-15T23:59:59.000Z
This paper is a summary report of the ICFA Beam Dynamics Workshop 'Accelerators for a Higgs Factory: Linear vs. Circular' (HF2012). It discusses four types of accelerators as possible candidates for a Higgs factory: linear e+e- colliders, circular e+e- colliders, muon collider and photon colliders. The comparison includes: physics reach, performance (energy and luminosity), upgrade potential, technology maturity and readiness, and technical challenges requiring further R&D.
Parameter choices for a muon recirculating linear accelerator from 5 to 63 GeV
Berg, J. S. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.
2014-06-19T23:59:59.000Z
A recirculating linear accelerator (RLA) has been proposed to accelerate muons from 5 to 63 GeV for a muon collider. It should be usable both for a Higgs factory and as a stage for a higher energy collider. First, the constraints due to the beam loading are computed. Next, an expression for the longitudinal emittance growth to lowest order in the longitudinal emittance is worked out. After finding the longitudinal expression, a simplified model that describes the arcs and their approximate expression for the time of flight dependence on energy in those arcs is found. Finally, these results are used to estimate the parameters required for the RLA arcs and the linac phase.
Lebrun, Philippe
2010-01-01T23:59:59.000Z
High-energy accelerators are large projects funded by public money, developed over the years and constructed via major industrial contracts both in advanced technology and in more conventional domains such as civil engineering and infrastructure, for which they often constitute one-of markets. Assessing their cost, as well as the risk and uncertainty associated with this assessment is therefore an essential part of project preparation and a justified requirement by the funding agencies. Stemming from the experience with large circular colliders at CERN, LEP and LHC, as well as with the Main Injector, the Tevatron Collider Experiments and Accelerator Upgrades, and the NOvA Experiment at Fermilab, we discuss sources of cost variance and derive cost risk assessment methods applicable to the future linear collider, through its two technical approaches for ILC and CLIC. We also address disparities in cost risk assessment imposed by regional differences in regulations, procedures and practices.
Optimal Linear Quadratic Regulator for Markovian Jump Linear Systems, in the
Baras, John S.
, in the last fifteen, the classical paradigms of optimal control for Markovian jump linear systems (see CostaOptimal Linear Quadratic Regulator for Markovian Jump Linear Systems, in the presence of one time] and in the design of controllers Chizeck [1986] of controllers for Markovian jump linear systems. More specifically
Grisham, Larry R
2013-12-17T23:59:59.000Z
The present invention provides systems and methods for the magnetic insulation of accelerator electrodes in electrostatic accelerators. Advantageously, the systems and methods of the present invention improve the practically obtainable performance of these electrostatic accelerators by addressing, among other things, voltage holding problems and conditioning issues. The problems and issues are addressed by flowing electric currents along these accelerator electrodes to produce magnetic fields that envelope the accelerator electrodes and their support structures, so as to prevent very low energy electrons from leaving the surfaces of the accelerator electrodes and subsequently picking up energy from the surrounding electric field. In various applications, this magnetic insulation must only produce modest gains in voltage holding capability to represent a significant achievement.
E-157: A 1.4-m-long plasma wake field acceleration experiment using a 30 GeV electron beam from conducted at the Stanford Linear Accelerator Center, a 30 GeV electron beam of 2 1010 electrons in a 0.65-mm beam density is greater than the plasma density, and the head of the bunch expels the plasma electrons
Dual-range linearized transimpedance amplifier system
Wessendorf, Kurt O. (Albuquerque, NM)
2010-11-02T23:59:59.000Z
A transimpedance amplifier system is disclosed which simultaneously generates a low-gain output signal and a high-gain output signal from an input current signal using a single transimpedance amplifier having two different feedback loops with different amplification factors to generate two different output voltage signals. One of the feedback loops includes a resistor, and the other feedback loop includes another resistor in series with one or more diodes. The transimpedance amplifier system includes a signal linearizer to linearize one or both of the low- and high-gain output signals by scaling and adding the two output voltage signals from the transimpedance amplifier. The signal linearizer can be formed either as an analog device using one or two summing amplifiers, or alternately can be formed as a digital device using two analog-to-digital converters and a digital signal processor (e.g. a microprocessor or a computer).
STABILIZING SUPERVISORY CONTROL OF HYBRID SYSTEMS BASED ON PIECEWISE LINEAR
Antsaklis, Panos
STABILIZING SUPERVISORY CONTROL OF HYBRID SYSTEMS BASED ON PIECEWISE LINEAR LYAPUNOV FUNCTIONS1 Lyapunov func- tions. In particular, we consider discrete-time switched linear systems. The control problem of discrete-time piecewise linear hybrid systems is in- vestigated using piecewise linear Lyapunov functions
Controllability of Linear Systems with inner derivation on Lie Groups
Boyer, Edmond
Controllability of Linear Systems with inner derivation on Lie Groups Philippe JOUAN November 2 group of automorphisms. A control-ane system is linear if the drift is linear and the controlled vector groups are stated. The paper ends by many examples. Keywords: Lie groups; Linear systems; controllability
1. INTRODUCTION It is relatively easy to control linear systems.
Wilamowski, Bogdan Maciej
of the biggest challenges in modern control theory. While linear control system theory has been well developed1. INTRODUCTION It is relatively easy to control linear systems. Unfortunately, in practice most systems are nonlinear. Some of them can be linearized and use well developed linear control theory
Kunkel, Peter
The linear quadratic optimal control problem for linear descriptor systems with variable coefficients Peter Kunkel 3 Volker Mehrmann y 17.01.97 Abstract We study linear quadratic optimal control, 93B11, 93B40 1 Introduction In this paper we study the linearÂquadratic optimal control problem
Neutron source, linear-accelerator fuel enricher and regenerator and associated methods
Steinberg, Meyer (Huntington Station, NY); Powell, James R. (Shoreham, NY); Takahashi, Hiroshi (Setauket, NY); Grand, Pierre (Blue Point, NY); Kouts, Herbert (Brookhaven, NY)
1982-01-01T23:59:59.000Z
A device for producing fissile material inside of fabricated nuclear elements so that they can be used to produce power in nuclear power reactors. Fuel elements, for example, of a LWR are placed in pressure tubes in a vessel surrounding a liquid lead-bismuth flowing columnar target. A linear-accelerator proton beam enters the side of the vessel and impinges on the dispersed liquid lead-bismuth columns and produces neutrons which radiate through the surrounding pressure tube assembly or blanket containing the nuclear fuel elements. These neutrons are absorbed by the natural fertile uranium-238 elements and are transformed to fissile plutonium-239. The fertile fuel is thus enriched in fissile material to a concentration whereby they can be used in power reactors. After use in the power reactors, dispensed depleted fuel elements can be reinserted into the pressure tubes surrounding the target and the nuclear fuel regenerated for further burning in the power reactor.
Integer Algorithms to Solver Diophantine Linear Equations and Systems
Florentin Smarandache
2007-11-28T23:59:59.000Z
The present work includes some of the author's original researches on integer solutions of Diophantine liner equations and systems. The notion of "general integer solution" of a Diophantine linear equation with two unknowns is extended to Diophantine linear equations with $n$ unknowns and then to Diophantine linear systems. The proprieties of the general integer solution are determined (both for a Diophantine linear equation and for a Diophantine linear system). Seven original integer algorithms (two for Diophantine linear equations, and five for Diophantine linear systems) are exposed. The algorithms are strictly proved and an example for each of them is given. These algorithms can be easily implemented on the computer.
Electron beam dynamics in the long-pulse, high-current DARHT-II linear induction accelerator
Ekdahl, Carl A [Los Alamos National Laboratory; Abeyta, Epifanio O [Los Alamos National Laboratory; Aragon, Paul [Los Alamos National Laboratory; Archuleta, Rita [Los Alamos National Laboratory; Cook, Gerald [Los Alamos National Laboratory; Dalmas, Dale [Los Alamos National Laboratory; Esquibel, Kevin [Los Alamos National Laboratory; Gallegos, Robert A [Los Alamos National Laboratory; Garnett, Robert [Los Alamos National Laboratory; Harrison, James F [Los Alamos National Laboratory; Johnson, Jeffrey B [Los Alamos National Laboratory; Jacquez, Edward B [Los Alamos National Laboratory; Mccuistian, Brian T [Los Alamos National Laboratory; Montoya, Nicholas A [Los Alamos National Laboratory; Nath, Subrato [Los Alamos National Laboratory; Nielsen, Kurt [Los Alamos National Laboratory; Oro, David [Los Alamos National Laboratory; Prichard, Benjamin [Los Alamos National Laboratory; Rowton, Lawrence [Los Alamos National Laboratory; Sanchez, Manolito [Los Alamos National Laboratory; Scarpetti, Raymond [Los Alamos National Laboratory; Schauer, Martin M [Los Alamos National Laboratory; Seitz, Gerald [Los Alamos National Laboratory; Schulze, Martin [Los Alamos National Laboratory; Bender, Howard A [Los Alamos National Laboratory; Broste, William B [Los Alamos National Laboratory; Carlson, Carl A [Los Alamos National Laboratory; Frayer, Daniel K [Los Alamos National Laboratory; Johnson, Douglas E [Los Alamos National Laboratory; Tom, C Y [Los Alamos National Laboratory; Williams, John [Los Alamos National Laboratory; Hughes, Thomas [Los Alamos National Laboratory; Anaya, Richard [LLNL; Caporaso, George [LLNL; Chambers, Frank [LLNL; Chen, Yu - Jiuan [LLNL; Falabella, Steve [LLNL; Guethlein, Gary [LLNL; Raymond, Brett [LLNL; Richardson, Roger [LLNL; Trainham, C [NSTEC/STL; Watson, Jim [LLNL; Weir, John [LLNL; Genoni, Thomas [VOSS; Toma, Carsten [VOSS
2009-01-01T23:59:59.000Z
The DARHT-II linear induction accelerator (LIA) now accelerates 2-kA electron beams to more than 17 MeV. This LIA is unique in that the accelerated current pulse width is greater than 2 microseconds. This pulse has a flat-top region where the final electron kinetic energy varies by less than 1% for more than 1.5 microseconds. The long risetime of the 6-cell injector current pulse is 0.5 {micro}s, which can be scraped off in a beam-head cleanup zone before entering the 68-cell main accelerator. We discuss our experience with tuning this novel accelerator; and present data for the resulting beam transport and dynamics. We also present beam stability data, and relate these to previous stability experiments at lower current and energy.
X-Band klystron development at the Stanford Linear Accelerator Center
Sprehn, D.W.
2000-03-24T23:59:59.000Z
X-band klystrons capable of 75 MW and utilizing either solenoidal or Periodic Permanent Magnet (PPM) focusing are undergoing design, fabrication and testing at the Stanford Linear Accelerator Center (SLAC). The klystron development is part of an effort to realize components necessary for the construction of the Next Linear Collider (NLC). SLAC has completed a solenoidal-focused X-band klystron development effort to study the design and operation of tubes with beam microperveances of 1.2. As of early 2000, nine 1.2{micro}K klystrons have been tested to 50 MW at 1.5{micro}s. The first 50 MW PPM klystron, constructed in 1996, was designed with a 0.6 {micro}K beam at 465 kV and uses a 5-cell traveling-wave output structure. Recent testing of this tube at wider pulsewidths has reached 50 MW at 55% efficiency, 2.4{micro}s and 60 Hz. A 75 MW PPM klystron prototype was constructed in 1998 and has reached the NLC design target of 75 MW at 1.5 {micro}s. A new 75 MW PPM klystron design, which is aimed at reducing the cost and increasing the reliability of multi-megawatt PPM klystrons, is under investigation. The tube is scheduled for testing during early 2001.
Proliferation Potential of Accelerator-Drive Systems: Feasibility Calculations
Riendeau, C.D.; Moses, D.L.; Olson, A.P.
1998-11-01T23:59:59.000Z
Accelerator-driven systems for fissile materials production have been proposed and studied since the early 1950s. Recent advances in beam power levels for small accelerators have raised the possibility that such use could be feasible for a potential proliferator. The objective of this study is to review the state of technology development for accelerator-driven spallation neutron sources and subcritical reactors. Energy and power requirements were calculated for a proton accelerator-driven neutron spallation source and subcritical reactors to produce a significant amount of fissile material--plutonium.
Stability and Controllability of Planar, Conewise Linear Systems
Broucke, Mireille E.
Stability and Controllability of Planar, Conewise Linear Systems Ari Arapostathis a,2 and Mireille and controllability of piecewise-linear systems defined on a conic partition of R2. This includes necessary. Key words: switched systems, piecewise linear systems, stability, controllability 1 Introduction
Accelerator Systems Division (ASD) | Advanced Photon Source
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Efficient scalable algorithms for solving dense linear systems with ...
2013-12-11T23:59:59.000Z
superfast direct solvers for both dense and sparse linear systems. ... Introduction. .... parallel HSS algorthms, taking into account communication latency and ...
Gao Song; Balter, Peter A. [Department of Radiation Physics, Unit 94, University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 (United States); Rose, Mark; Simon, William E. [Sun Nuclear Corporation, 425-A Pineda Court, Melbourne, Florida 32940 (United States)
2013-04-15T23:59:59.000Z
Purpose: To compare the use of flatness versus percent depth dose (PDD) for determining changes in photon beam energy for a megavoltage linear accelerator. Methods: Energy changes were accomplished by adjusting the bending magnet current by up to {+-}15% in 5% increments away from the value used clinically. Two metrics for flatness, relative flatness in the central 80% of the field (Flat) and average maximum dose along the diagonals normalized by central axis dose (F{sub DN}), were measured using a commercially available planner ionization chamber array. PDD was measured in water at depths of 5 and 10 cm in 3 Multiplication-Sign 3 cm{sup 2} and 10 Multiplication-Sign 10 cm{sup 2} fields using a cylindrical chamber. Results: PDD was more sensitive to changes in energy when the beam energy was increased than when it was decreased. For the 18-MV beam in particular, PDD was not sensitive to energy reductions below the nominal energy. The value of Flat was found to be more sensitive to decreases in energy than to increases, with little sensitivity to energy increases above the nominal energy for 18-MV beams. F{sub DN} was the only metric that was found to be sensitive to both increases and reductions of energy for both the 6- and 18-MV beams. Conclusions: Flatness based metrics were found to be more sensitive to energy changes than PDD, In particular, F{sub DN} was found to be the most sensitive metric to energy changes for photon beams of 6 and 18 MV. The ionization chamber array allows this metric to be conveniently measured as part of routine accelerator quality assurance.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Piot, P [Northern Illinois U.; Fermilab; Behrens, C; Gerth, C; Dohlus, M [DESY; Lemery, F; Mihalcea, D [Northern Illinois U.; Stoltz, P [Tech-X, Boulder; Vogt, M [DESY
2011-09-07T23:59:59.000Z
We report on the successful experimental generation of electron bunches with ramped current profiles. The technique relies on impressing nonlinear correlations in the longitudinal phase space using a superconducing radiofrequency linear accelerator operating at two frequencies and a current-enhancing dispersive section. The produced {approx} 700-MeV bunches have peak currents of the order of a kilo-Ampere. Data taken for various accelerator settings demonstrate the versatility of the method and in particular its ability to produce current profiles that have a quasi-linear dependency on the longitudinal (temporal) coordinate. The measured bunch parameters are shown, via numerical simulations, to produce gigavolt-per-meter peak accelerating electric fields with transformer ratios larger than 2 in dielectric-lined waveguides.
Piot, P; Gerth, C; Dohlus, M; Lemery, F; Mihalcea, D; Stoltz, P; Vogt, M
2011-01-01T23:59:59.000Z
We report on the successful experimental generation of electron bunches with ramped current profiles. The technique relies on impressing nonlinear correlations in the longitudinal phase space using a superconducing radiofrequency linear accelerator operating at two frequencies and a current-enhancing dispersive section. The produced $\\sim 700$-MeV bunches have peak currents of the order of a kilo-Amp\\`ere. Data taken for various accelerator settings demonstrate the versatility of the method and in particular its ability to produce current profiles that have a quasi-linear dependency on the longitudinal (temporal) coordinate. The measured bunch parameters are shown, via numerical simulations, to produce gigavolt-per-meter peak accelerating electric fields with transformer ratios larger than 2 in dielectric-lined waveguides.
LINEAR CONTROL SYSTEMS OVER ORE ALGEBRAS: EFFECTIVE ALGORITHMS FOR
Robertz, Daniel
LINEAR CONTROL SYSTEMS OVER ORE ALGEBRAS: EFFECTIVE ALGORITHMS FOR THE COMPUTATION@momo.math.rwth-aachen.de. Abstract: In this paper, we study linear control systems over Ore algebras. Within this mathematical framework, we can simultaneously deal with different classes of linear control systems such as time
Linearization of affine connection control system David R. Tyner
Lewis, Andrew D.
Linearization of affine connection control system David R. Tyner 22/09/2002 Abstract A simple system. If these systems are underactuated then they do not provide a control- lable linearization about their equilibrium points. Without a controllable linearization it is not entirely clear how one should deriving
Infinite-dimensional linear systems: a distributional approach
Opmeer, Mark
resolvent linear system and solve the linear quadratic optimal control problem for this class of systems contributions to the linear quadratic optimal control problem for operators on infinite-dimensional spaces. We quadratic optimal control problem on a finite time horizon for this class 1 #12;of systems. The infinite
OPTIMAL CONTROL OF LINEAR SYSTEMS WITH STATE EQUALITY CONSTRAINTS
Bitmead, Bob
, a number of modern model-based control design methods sought to deal with system constraints directlyOPTIMAL CONTROL OF LINEAR SYSTEMS WITH STATE EQUALITY CONSTRAINTS Sangho Ko , Robert R. Bitmead 1 with the optimal control problem for systems with state linear equality constraints. For deterministic linear
Krylov space solvers for shifted linear systems
B. Jegerlehner
1996-12-15T23:59:59.000Z
We investigate the application of Krylov space methods to the solution of shifted linear systems of the form (A+\\sigma) x - b = 0 for several values of \\sigma simultaneously, using only as many matrix-vector operations as the solution of a single system requires. We find a suitable description of the problem, allowing us to understand known algorithms in a common framework and developing shifted methods basing on short recurrence methods, most notably the CG and the BiCGstab solvers. The convergence properties of these shifted solvers are well understood and the derivation of other shifted solvers is easily possible. The application of these methods to quark propagator calculations in quenched QCD using Wilson and Clover fermions is discussed and numerical examples in this framework are presented. With the shifted CG method an optimal algorithm for staggered fermions is available.
Tian, Zhen; Folkerts, Michael; Shi, Feng; Jiang, Steve B; Jia, Xun
2015-01-01T23:59:59.000Z
Monte Carlo (MC) simulation is considered as the most accurate method for radiation dose calculations. Accuracy of a source model for a linear accelerator is critical for the overall dose calculation accuracy. In this paper, we presented an analytical source model that we recently developed for GPU-based MC dose calculations. A key concept called phase-space-ring (PSR) was proposed. It contained a group of particles that are of the same type and close in energy and radial distance to the center of the phase-space plane. The model parameterized probability densities of particle location, direction and energy for each primary photon PSR, scattered photon PSR and electron PSR. For a primary photon PSRs, the particle direction is assumed to be from the beam spot. A finite spot size is modeled with a 2D Gaussian distribution. For a scattered photon PSR, multiple Gaussian components were used to model the particle direction. The direction distribution of an electron PSRs was also modeled as a 2D Gaussian distributi...
Linear induction accelerators at the Los Alamos National Laboratory DARHT facility
Nath, Subrata [Los Alamos National Laboratory
2010-09-07T23:59:59.000Z
The Dual-Axis Radiographic Hydrodynamic Test Facility (DARHT) at Los Alamos National Laboratory consists of two linear induction accelerators at right angles to each other. The First Axis, operating since 1999, produces a nominal 20-MeV, 2-kA single beam-pulse with 60-nsec width. In contrast, the DARHT Second Axis, operating since 2008, produces up to four pulses in a variable pulse format by slicing micro-pulses out of a longer {approx}1.6-microseconds (flat-top) pulse of nominal beam-energy and -current of 17 MeV and 2 kA respectively. Bremsstrahlung x-rays, shining on a hydro-dynamical experimental device, are produced by focusing the electron beam-pulses onto a high-Z target. Variable pulse-formats allow for adjustment of the pulse-to-pulse doses to record a time sequence of x-ray images of the explosively driven imploding mock device. Herein, we present a sampling of the numerous physics and engineering aspects along with the current status of the fully operational dual axes capability. First successful simultaneous use of both the axes for a hydrodynamic experiment was achieved in 2009.
Disposition of Nuclear Waste Using Subcritical Accelerator-Driven Systems
Doolen, G.D.; Venneri, F.; Li, N.; Williamson, M.A.; Houts, M.; Lawrence, G.
1998-06-27T23:59:59.000Z
ATW destroys virtually all the plutonium and higher actinides without reprocessing the spent fuel in a way that could lead to weapons material diversion. An ATW facility consists of three major elements: (1) a high-power proton linear accelerator; (2) a pyrochemical spent fuel treatment i waste cleanup system; (3) a liquid lead-bismuth cooled burner that produces and utilizes an intense source-driven neutron flux for transmutation in a heterogeneous (solid fuel) core. The concept is the result of many years of development at LANL as well as other major international research centers. Once demonstrated and developed, ATW could be an essential part of a global non-proliferation strategy for countries that could build up large quantities of plutonium from their commercial reactor waste. ATW technology, initially proposed in the US, has received wide and rapidly increasing attention abroad, especially in Europe and the Far East with major programs now being planned, organized and tided. Substantial convergence presently exists on the technology choices among the programs, opening the possibility of a strong and effective international collaboration on the phased development of the ATW technology.
Advances in Normal Conducting Accelerator Technology from the X-Band Linear Collider Program
Adolphsen, Chris
2005-01-01T23:59:59.000Z
In the early 1990's, groups at SLAC and KEK began dedicated development of X-band (11.4 GHz) rf technology for a next generation, TeV-scale linear collider. The choice of a relatively high frequency, four times that of the SLAC 50 GeV Linac, was motivated by the cost benefits of having lower rf energy per pulse (hence fewer rf components) and reasonable efficiencies at high gradients (hence shorter linacs). However, to realize such savings requires operation at gradients and peak powers much higher than that hitherto achieved. During the past 15 years, these challenges were met through innovations on several fronts, and resulted in a viable rf system design for a linear collider. This paper reviews these achievements, which include developments in the generation and transport of high power rf, and new insights into high gradient limitations.
Upcoming Numerical Linear Algebra Issues in Systems and Control Theory
Upcoming Numerical Linear Algebra Issues in Systems and Control Theory Paul Van Dooren University in the interdisciplinary area of numerical linear algebra and systems and control theory. Although we do not claimto, and normalized coprime factorizations in robust control. Key words. Numerical algorithms, linear algebra, sparse
Optimal linear control systems with input derivative constraints
Moore, John Barratt
. Optimal linear control systems with input derivative constraints J. B. Moore, Ph. D., and Prof. B-loss-function minimisation problem is linear. The "paper applies the results of this optimal control theory to a class of performance desired. For linear, finite-dimensional, completely controllable systems, Kalmanl has shown
Upcoming Numerical Linear Algebra Issues in Systems and Control Theory
Upcoming Numerical Linear Algebra Issues in Systems and Control Theory Paul Van Dooren University in the interdisciplinary area of numerical linear algebra and systems and control theory. Although we do not claim, and normalized coprime factorizations in robust control. Key words. Numerical algorithms, linear algebra, sparse
Communication channel of fermionic system in accelerated frame
Jinho Chang; Younghun Kwon
2012-08-23T23:59:59.000Z
In this article, we investigate the communication channel of fermionic system in an accelerated frame. We observe that at the infinite acceleration, the mutual information of single rail quantum channel coincides with that of double rail quantum channel, but those of classical ones reach different values. Furthermore, we find that at the infinite acceleration, the conditional entropy of single(or double) rail quantum channel vanishes, but those of classical ones may have finite values. In addition, we see that even when considering a method beyond the single mode approximation, the dual rail entangled state seems to provide better channel capacity than the single rail entangled state, unlike the bosonic case. Moreover, we find that the single-mode approximation is not sufficient to analyze the communication channel of fermionic system in an accelerated frame.
The Brookhaven National Laboratory Accelerator Test Facility
Batchelor, K.
1992-01-01T23:59:59.000Z
The Brookhaven National Laboratory Accelerator Test Facility comprises a 50 MeV traveling wave electron linear accelerator utilizing a high gradient, photo-excited, raidofrequency electron gun as an injector and an experimental area for study of new acceleration methods or advanced radiation sources using free electron lasers. Early operation of the linear accelerator system including calculated and measured beam parameters are presented together with the experimental program for accelerator physics and free electron laser studies.
The Brookhaven National Laboratory Accelerator Test Facility
Batchelor, K.
1992-09-01T23:59:59.000Z
The Brookhaven National Laboratory Accelerator Test Facility comprises a 50 MeV traveling wave electron linear accelerator utilizing a high gradient, photo-excited, raidofrequency electron gun as an injector and an experimental area for study of new acceleration methods or advanced radiation sources using free electron lasers. Early operation of the linear accelerator system including calculated and measured beam parameters are presented together with the experimental program for accelerator physics and free electron laser studies.
A general solution to non-linear particle acceleration at non-relativistic shock waves
Elena Amato; Pasquale Blasi
2005-09-22T23:59:59.000Z
Diffusive acceleration at collisionless shock waves remains one of the most promising acceleration mechanisms for the description of the origin of cosmic rays at all energies. A crucial ingredient to be taken into account is the reaction of accelerated particles on the shock, which in turn determines the efficiency of the process. Here we propose a semi-analytical kinetic method that allows us to calculate the shock modification induced by accelerated particles together with the efficiency for particle acceleration and the spectra of accelerated particles. The shock modification is calculated for arbitrary environment parameters (Mach number, maximum momentum, density) and for arbitrary diffusion properties of the medium. Several dependences of the diffusion coefficient on particle momentum and location are considered to assess the goodness of the method.
Linear_Accelerator_C+6_Ions_as_Injector_for_a_Synchrotron, Intended for Hadrons Therapy
Dolya, S N
2013-01-01T23:59:59.000Z
We consider acceleration light ions by the field of a traveling-wave in a helical waveguide. The frequency of the accelerating RF field f = 100 MHz, generator power P = 2 MW. Ion focusing is provided by a solenoidal magnetic field with the intensity B = 3.5 Tesla. With increasing the accelerator length up to L = 15 m, the final energy of the ions can be increased up to a value of E = 7 MeV / nucleon.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Piot, P; Fermilab; Behrens, C; Gerth, C; Dohlus, M; Lemery, F; Mihalcea, D; Stoltz, P; Vogt, M
2011-09-07T23:59:59.000Z
We report on the successful experimental generation of electron bunches with ramped current profiles. The technique relies on impressing nonlinear correlations in the longitudinal phase space using a superconducing radiofrequency linear accelerator operating at two frequencies and a current-enhancing dispersive section. The produced {approx} 700-MeV bunches have peak currents of the order of a kilo-Ampere. Data taken for various accelerator settings demonstrate the versatility of the method and in particular its ability to produce current profiles that have a quasi-linear dependency on the longitudinal (temporal) coordinate. The measured bunch parameters are shown, via numerical simulations, to produce gigavolt-per-meter peak acceleratingmore »electric fields with transformer ratios larger than 2 in dielectric-lined waveguides.« less
Klystron based high power rf system for proton accelerator
Pande, Manjiri; Shrotriya, Sandip; Sharma, Sonal; Patel, Niranjan; Handu, Verander, E-mail: manjiri@barc.gov.in, E-mail: manjiri08@gmail.com [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai (India)
2011-07-01T23:59:59.000Z
As a part of ADS program a proton accelerator (20 MeV, 30 mA) and its high power RF systems (HPRF) are being developed in BARC. This paper explains design details of this klystron based HPRF system. (author)
Non-linear system identification in flow-induced vibration
Spanos, P.D.; Zeldin, B.A. [Rice Univ., Houston, TX (United States); Lu, R. [Hudson Engineering Corp., Houston, TX (United States)
1996-12-31T23:59:59.000Z
The paper introduces a method of identification of non-linear systems encountered in marine engineering applications. The non-linearity is accounted for by a combination of linear subsystems and known zero-memory non-linear transformations; an equivalent linear multi-input-single-output (MISO) system is developed for the identification problem. The unknown transfer functions of the MISO system are identified by assembling a system of linear equations in the frequency domain. This system is solved by performing the Cholesky decomposition of a related matrix. It is shown that the proposed identification method can be interpreted as a {open_quotes}Gram-Schmidt{close_quotes} type of orthogonal decomposition of the input-output quantities of the equivalent MISO system. A numerical example involving the identification of unknown parameters of flow (ocean wave) induced forces on offshore structures elucidates the applicability of the proposed method.
High Performance Dense Linear System Solver with Soft Error Resilience
Dongarra, Jack
High Performance Dense Linear System Solver with Soft Error Resilience Peng Du, Piotr Luszczek systems, and in some scientific applications C/R is not applicable for soft error at all due to error) high performance dense linear system solver with soft error resilience. By adopting a mathematical
Optimization Online - Global Optimization of Non-Linear Systems of ...
Nicholas Harkiolakis
2008-10-20T23:59:59.000Z
Oct 20, 2008 ... Global Optimization of Non-Linear Systems of Equations by Simulating the ... 10th WSEAS International Conference on Mathematical Methods, ...
Hardware Accelerator for MIMO Wireless Systems
Bhagawat, Pankaj
2012-02-14T23:59:59.000Z
potential that multiple antenna systems promise. Furthermore, in order to make judicious use of the available bandwidth, the baseband units have to dynamically adapt to different modes (modulation schemes, code rates etc) of operations. Flexibility and high...
An integrated 6 MV linear accelerator model from electron gun to dose in a water tank
St Aubin, J.; Steciw, S.; Kirkby, C.; Fallone, B. G. [Department of Physics, University of Alberta, 11322-89 Avenue, Edmonton, Alberta T6G 2G7 (Canada) and Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada) and Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Department of Physics, University of Alberta, 11322-89 Avenue, Edmonton, Alberta T6G 2G7 (Canada); Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada) and Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada)
2010-05-15T23:59:59.000Z
Purpose: The details of a full simulation of an inline side-coupled 6 MV linear accelerator (linac) from the electron gun to the target are presented. Commissioning of the above simulation was performed by using the derived electron phase space at the target as an input into Monte Carlo studies of dose distributions within a water tank and matching the simulation results to measurement data. This work is motivated by linac-MR studies, where a validated full linac simulation is first required in order to perform future studies on linac performance in the presence of an external magnetic field. Methods: An electron gun was initially designed and optimized with a 2D finite difference program using Child's law. The electron gun simulation served as an input to a 6 MV linac waveguide simulation, which consisted of a 3D finite element radio-frequency field solution within the waveguide and electron trajectories determined from particle dynamics modeling. The electron gun design was constrained to match the cathode potential and electron gun current of a Varian 600C, while the linac waveguide was optimized to match the measured target current. Commissioning of the full simulation was performed by matching the simulated Monte Carlo dose distributions in a water tank to measured distributions. Results: The full linac simulation matched all the electrical measurements taken from a Varian 600C and the commissioning process lead to excellent agreements in the dose profile measurements. Greater than 99% of all points met a 1%/1mm acceptance criterion for all field sizes analyzed, with the exception of the largest 40x40 cm{sup 2} field for which 98% of all points met the 1%/1mm acceptance criterion and the depth dose curves matched measurement to within 1% deeper than 1.5 cm depth. The optimized energy and spatial intensity distributions, as given by the commissioning process, were determined to be non-Gaussian in form for the inline side-coupled 6 MV linac simulated. Conclusions: An integrated simulation of an inline side-coupled 6 MV linac has been completed and benchmarked matching all electrical and dosimetric measurements to high accuracy. The results showed non-Gaussian spatial intensity and energy distributions for the linac modeled.
Relative Humidity in Limited Streamer Tubes for Stanford Linear Accelerator Center's BaBar Detector
Lang, M.I.; /MIT; Convery, M.; /SLAC; Menges, W.; /Queen Mary, U. of London
2005-12-15T23:59:59.000Z
The BABAR Detector at the Stanford Linear Accelerator Center studies the decay of B mesons created in e{sup +}e{sup -} collisions. The outermost layer of the detector, used to detect muons and neutral hadrons created during this process, is being upgraded from Resistive Plate Chambers (RPCs) to Limited Streamer Tubes (LSTs). The standard-size LST tube consists of eight cells, where a silver-plated wire runs down the center of each. A large potential difference is placed between the wires and ground. Gas flows through a series of modules connected with tubing, typically four. LSTs must be carefully tested before installation, as it will be extremely difficult to repair any damage once installed in the detector. In the testing process, the count rate in most modules showed was stable and consistent with cosmic ray rate over an approximately 500 V operating range between 5400 to 5900 V. The count in some modules, however, was shown to unexpectedly spike near the operation point. In general, the modules through which the gas first flows did not show this problem, but those further along the gas chain were much more likely to do so. The suggestion was that this spike was due to higher humidity in the modules furthest from the fresh, dry inflowing gas, and that the water molecules in more humid modules were adversely affecting the modules' performance. This project studied the effect of humidity in the modules, using a small capacitive humidity sensor (Honeywell). The sensor provided a humidity-dependent output voltage, as well as a temperature measurement from a thermistor. A full-size hygrometer (Panametrics) was used for testing and calibrating the Honeywell sensors. First the relative humidity of the air was measured. For the full calibration, a special gas-mixing setup was used, where relative humidity of the LST gas mixture could be varied from almost dry to almost fully saturated. With the sensor calibrated, a set of sensors was used to measure humidity vs. time in the LSTs. The sensors were placed in two sets of LST modules, one gas line flowing through each set. These modules were tested for count rate v. voltage while simultaneously measuring relative humidity in each module. One set produced expected readings, while the other showed the spike in count rate. The relative humidity in the two sets of modules looked very similar, but it rose significantly for modules further along the gas chain.
Electronic Non-Contacting Linear Position Measuring System
Post, Richard F. (Walnut Creek, CA)
2005-06-14T23:59:59.000Z
A non-contacting linear position location system employs a special transmission line to encode and transmit magnetic signals to a receiver on the object whose position is to be measured. The invention is useful as a non-contact linear locator of moving objects, e.g., to determine the location of a magnetic-levitation train for the operation of the linear-synchronous motor drive system.
McDonald, R.J. (ed.)
1987-09-01T23:59:59.000Z
This report consists of a description of the accelerator facilities and a review of research programs being conducted there. Lists of SuperHILAC researchers and publications are also given.
Methods for Estimation and Control of Linear Systems Driven by Cauchy Noises
Fernandez, Javier Huerta
2013-01-01T23:59:59.000Z
prediction optimal control for a scalar linear system withPrediction Optimal Control for a Scalar Linear System withsystems in modern stochastic optimal control, algorithms like the linear
Chapter 5 -Linear Systems Math 267, Ordinary differential equations
-1). #12;Chapter 5 - Linear Systems Spring-mass-spring-mass, Brine tanks I Example 1 Two carts;Chapter 5 - Linear Systems Spring-mass-spring-mass, Brine tanks II computed. Brine (saltwater) goes from 1 at 20 gal/min and brine flows out of tank 2 at 20 gal/min. This can be written as x = - 3 10 x + 1
POLYGRAPHS FOR TERMINATION OF LEFT-LINEAR TERM REWRITING SYSTEMS
Paris-Sud XI, Université de
POLYGRAPHS FOR TERMINATION OF LEFT-LINEAR TERM REWRITING SYSTEMS February 2, 2007 Yves GUIRAUD termination of left-linear term rewriting systems (TRSs) by using Albert Burroni's polygraphs, a kind whose termination is proven with a polygraphic interpretation, then we get back the property on the TRS
Linear programming model for optimum resource allocation in rural systems
Devadas, V. [Indian Inst. of Tech., Kharagpur (India)
1997-07-01T23:59:59.000Z
The article presents a model for optimum resource allocation in a rural system. Making use of linear programming, the objective function of the linear programming model is to maximize the revenue of the rural system, and optimum resource allocation is made subject to a number of energy- and nonenergy-related constraints relevant to the rural system. The model also quantifies the major yields as well as the by-products of different sectors of the rural economic system.
Artoos, K; Fernandez Carmona, P; Guinchard, M; Hauviller, C; Janssens, S; Kuzmin, A; Slaathaug, A
2010-01-01T23:59:59.000Z
To reach a sufficient luminosity, the transverse beam sizes and emittances in future linear particle accelerators should be reduced to the nanometer level. Mechanical stabilisation of the quadrupole magnets is of the utmost importance for this. The piezo actuators used for this purpose can also be used to make fast incremental orientation adjustments with a nanometer resolution. The main requirements for the CLIC stabilisation electronics is a robust, low noise, low delay, high accuracy and resolution, low band and radiation resistant feedback control loop. Due to the high number of controllers (about 4000) a cost optimization should also be made. Different architectures are evaluated for a magnet stabilisation prototype, including the sensors type and configuration, partition between software and hardware for control algorithms, and optimization of the ADC/DAC converters. The controllers will be distributed along the 50 km long accelerator and a communication bus should allow external control. Furthermore, o...
On Optimal Feedback Control for Stationary Linear Systems
Russell, David L., E-mail: russell@math.vt.ed [Virginia Tech, Department of Mathematics (United States)
2010-04-15T23:59:59.000Z
We study linear-quadratic optimal control problems for finite dimensional stationary linear systems AX+BU=Z with output Y=CX+DU from the viewpoint of linear feedback solution. We interpret solutions in relation to system robustness with respect to disturbances Z and relate them to nonlinear matrix equations of Riccati type and eigenvalue-eigenvector problems for the corresponding Hamiltonian system. Examples are included along with an indication of extensions to continuous, i.e., infinite dimensional, systems, primarily of elliptic type.
Simulation of the relativistic electron dynamics and acceleration in a linearly-chirped laser pulse
Jisrawi, Najeh M; Salamin, Yousef I
2014-01-01T23:59:59.000Z
Theoretical investigations are presented, and their results are discussed, of the laser acceleration of a single electron by a chirped pulse. Fields of the pulse are modeled by simple plane-wave oscillations and a $\\cos^2$ envelope. The dynamics emerge from analytic and numerical solutions to the relativistic Lorentz-Newton equations of motion of the electron in the fields of the pulse. All simulations have been carried out by independent Mathematica and Python codes, with identical results. Configurations of acceleration from a position of rest as well as from injection, axially and sideways, at initial relativistic speeds are studied.
Alignment tolerance of accelerating structures and corrections for future linear colliders
Kubo, K.; Adolphsen, C.; Bane, K.L.F.; Raubenheimer, T.O.; Thompson, K.A.
1995-06-01T23:59:59.000Z
The alignment tolerance of accelerating structures is estimated by tracking simulations. Both single-bunch and multi-bunch effects are taken into account. Correction schemes for controlling the single and multi-bunch emittance growth in the case of large misalignment are also tested by simulations.
Broader source: Energy.gov [DOE]
This EA evaluates the environmental impacts of the proposed construction of the Linac Coherent Light Source at SLAC National Accelerator Laboratory, Menlo Park, California. None available at this time. For more information, contact: Mr. Dave Osugi DOE SLAC Site Office 2575 Sand Hill Road, MS8A Menlo Park, CA 94025 E-mail: dave.osugi@sso.science.doe.gov
Acceleration Control in Nonlinear Vibrating Systems based on Damped Least Squares
Pilipchuk, V N
2011-01-01T23:59:59.000Z
A discrete time control algorithm using the damped least squares is introduced for acceleration and energy exchange controls in nonlinear vibrating systems. It is shown that the damping constant of least squares and sampling time step of the controller must be inversely related to insure that vanishing the time step has little effect on the results. The algorithm is illustrated on two linearly coupled Duffing oscillators near the 1:1 internal resonance. In particular, it is shown that varying the dissipation ratio of one of the two oscillators can significantly suppress the nonlinear beat phenomenon.
Institute of Radiological Sciences Rev. Sci. Instrum. 83, 02A332 (2012) Concepts for the magnetic design of the MITICA neutral beam test facility ion accelerator Rev. Sci. Instrum. 83, 02B107 (2012) A 2 MV Van de, Z, and the National Ignition Facility (NIF). Sig- nificant improvements to the system in recent
Syllabus: EE 313 Linear Signals and Systems Spring 2012 1
Heath Jr., - Robert W.
, and biomedical engineering among others. The emphasis of this course is on signal processing tools but we Linear Signals and Systems Spring 2012 2 Course Introduction Signal processing is rich with tools will be your first introduction to the concepts of signal processing, especially processing signals with linear
Output regulation problem for differentiable families of linear systems
PolitÃ¨cnica de Catalunya, Universitat
The output regulation problem arose as one of the main research topics in linear control theory in the 1970s regulation when modeled by a global or a local differentiable family. Partially supported by DGICYT n.PB97Output regulation problem for differentiable families of linear systems Albert Compta and Marta Pe
Modal approximations to damped linear systems
K. Veseli/'c
2009-07-01T23:59:59.000Z
We consider a finite dimensional damped second order system and obtain spectral inclusion theorems for the related quadratic eigenvalue problem. The inclusion sets are the 'quasi Cassini ovals' which may greatly outperform standard Gershgorin circles. As the unperturbed system we take a modally damped part of the system; this includes the known proportionally damped models, but may give much sharper estimates. These inclusions are then applied to derive some easily calculable sufficient conditions for the overdampedness of a given damped system.
Quick setup of unit test for accelerator controls system
Fu, W.; D'Ottavio, T.; Gassner, D.; Nemesure, S.; Morris, J.
2011-03-28T23:59:59.000Z
Testing a single hardware unit of an accelerator control system often requires the setup of a program with graphical user interface. Developing a dedicated application for a specific hardware unit test could be time consuming and the application may become obsolete after the unit tests. This paper documents a methodology for quick design and setup of an interface focused on performing unit tests of accelerator equipment with minimum programming work. The method has three components. The first is a generic accelerator device object (ADO) manager which can be used to setup, store, and log testing controls parameters for any unit testing system. The second involves the design of a TAPE (Tool for Automated Procedure Execution) sequence file that specifies and implements all te testing and control logic. The sting third is the design of a PET (parameter editing tool) page that provides the unit tester with all the necessary control parameters required for testing. This approach has been used for testing the horizontal plane of the Stochastic Cooling Motion Control System at RHIC.
Feasibility of an XUV FEL Oscillator Driven by a SCRF Linear Accelerator
Lumpkin, A. H.; Freund, H. P.; Reinsch, M.
2014-01-01T23:59:59.000Z
The Advanced Superconducting Test Accelerator (ASTA) facility is currently under construction at Fermi National Accelerator Laboratory. Using a1-ms-long macropulse composed of up to 3000 micropulses, and with beam energies projected from 45 to 800 MeV, the possibility for an extreme ultraviolet (XUV) free-electron laser oscillator (FELO) with the higher energy is evaluated. We have used both GINGER with an oscillator module and the MEDUSA/OPC code to assess FELO saturation prospects at 120 nm, 40 nm, and 13.4 nm. The results support saturation at all of these wavelengths which are also shorter than the demonstrated shortest wavelength record of 176 nm from a storage-ring-based FELO. This indicates linac-driven FELOs can be extended into this XUV wavelength regime previously only reached with single-pass FEL configurations.
Andreas Stathopoulos; Kostas Orginos
2008-06-12T23:59:59.000Z
We present a new algorithm that computes eigenvalues and eigenvectors of a Hermitian positive definite matrix while solving a linear system of equations with Conjugate Gradient (CG). Traditionally, all the CG iteration vectors could be saved and recombined through the eigenvectors of the tridiagonal projection matrix, which is equivalent theoretically to unrestarted Lanczos. Our algorithm capitalizes on the iteration vectors produced by CG to update only a small window of vectors that approximate the eigenvectors. While this window is restarted in a locally optimal way, the CG algorithm for the linear system is unaffected. Yet, in all our experiments, this small window converges to the required eigenvectors at a rate identical to unrestarted Lanczos. After the solution of the linear system, eigenvectors that have not accurately converged can be improved in an incremental fashion by solving additional linear systems. In this case, eigenvectors identified in earlier systems can be used to deflate, and thus accelerate, the convergence of subsequent systems. We have used this algorithm with excellent results in lattice QCD applications, where hundreds of right hand sides may be needed. Specifically, about 70 eigenvectors are obtained to full accuracy after solving 24 right hand sides. Deflating these from the large number of subsequent right hand sides removes the dreaded critical slowdown, where the conditioning of the matrix increases as the quark mass reaches a critical value. Our experiments show almost a constant number of iterations for our method, regardless of quark mass, and speedups of 8 over original CG for light quark masses.
Moment-linear stochastic systems and their applications
Roy, Sandip, 1978-
2003-01-01T23:59:59.000Z
Our work is motivated by the need for tractable stochastic models for complex network and system dynamics. With this motivation in mind, we develop a class of discrete-time Markov models, called moment-linear stochastic ...
Russell, Steven J. [Los Alamos National Laboratory; Carlsten, Bruce E. [Los Alamos National Laboratory
2012-06-26T23:59:59.000Z
We will quickly go through the history of the non-linear transmission lines (NLTLs). We will describe how they work, how they are modeled and how they are designed. Note that the field of high power, NLTL microwave sources is still under development, so this is just a snap shot of their current state. Topics discussed are: (1) Introduction to solitons and the KdV equation; (2) The lumped element non-linear transmission line; (3) Solution of the KdV equation; (4) Non-linear transmission lines at microwave frequencies; (5) Numerical methods for NLTL analysis; (6) Unipolar versus bipolar input; (7) High power NLTL pioneers; (8) Resistive versus reactive load; (9) Non-lineaer dielectrics; and (10) Effect of losses.
Feed forward rf control system of the accelerator test facility
Ben-Zvi, I.; Xie, Jialin; Zhang, Renshan.
1991-01-01T23:59:59.000Z
We report a scheme to control the amplitude and phase of the rf accelerating field in a klystron driven electron linac. The amplitude and phase distribution within the rf pulse can be controlled to follow specified functions to reduce the energy spread of the electron beam being accelerated. The scheme employs fast beam energy and phase detectors and voltage-controlled electronic attenuator and phase shifter in the amplifier chain. The control voltages of these devices are generated by arbitrary function generators. The function generators' outputs are calculated numerically using an algorithm which takes into consideration the desired target function and the deviation (due to load variations or system parameter drift) from the target function. Results of preliminary tests on producing flat rf power and phase pulses from a high power klystron indicate that amplitude variation of {plus minus}0.2% and phase variation of {plus minus}1{degree} can be readily achieved. 4 refs., 3 figs.
Cavity beam position monitor system for the Accelerator Test Facility 2
Kim, Y.I.; /Kyungpook Natl. U.; Ainsworth, R.; /Royal Holloway, U. of London; Aryshev, A.; /KEK, Tsukuba; Boogert, S.T.; Boorman, G.; /Royal Holloway, U. of London; Frisch, J.; /SLAC; Heo, A.; /Kyungpook Natl. U.; Honda, Y.; /KEK, Tsukuba; Hwang, W.H.; Huang, J.Y.; /Pohang Accelerator Lab.; Kim, E-S.; /Kyungpook Natl. U. /Pohang Accelerator Lab. /Royal Holloway, U. of London /KEK, Tsukuba
2012-04-02T23:59:59.000Z
The Accelerator Test Facility 2 (ATF2) is a scaled demonstrator system for final focus beam lines of linear high energy colliders. This paper describes the high resolution cavity beam position monitor (BPM) system, which is a part of the ATF2 diagnostics. Two types of cavity BPMs are used, C-band operating at 6.423 GHz, and S-band at 2.888 GHz with an increased beam aperture. The cavities, electronics, and digital processing are described. The resolution of the C-band system with attenuators was determined to be approximately 250 nm and 1 {mu}m for the S-band system. Without attenuation the best recorded C-band cavity resolution was 27 nm.
Exercises UNIVERSITY OF TWENTE. Linear Systems
Vellekoop, Michel
) Find the homogeneous solution. b) Find the impulse response. c) Find the step response s(t) (the(t) = 2x(t). a) Find the homogeneous solution. b) Find the impulse response. c) Find the step response s response s(t) of a system is the response of a system to the step signal u(t). Show that the step response
Optimal Control of Linear Systems with State Equality Constraints
Bitmead, Bob
system specifications. Recently, a number of modern model- based control design methods seek to dealOptimal Control of Linear Systems with State Equality Constraints Sangho Ko and Robert R. Bitmead and control community, since it is closely connected with system performance and, thus, fulfillment of given
Joint Optimization of Communication Rates and Linear Systems
Joint Optimization of Communication Rates and Linear Systems L. Xiao M. Johansson H. Hindi S. Boyd system, such as a controller or estimator, in which several signals are transmitted over communication in the design of networked controllers and the associated communication systems, including bit rate limitations
Model checking LTL over controllable linear systems is decidable
Pappas, George J.
Model checking LTL over controllable linear systems is decidable Paulo Tabuada and George J. Pappas Department of Electrical and Systems Engineering University of Pennsylvania Philadelphia, PA 19104 {tabuadap,pappasg}@seas.upenn.edu Abstract. The use of algorithmic verification and synthesis tools for hy- brid systems is currently limited
High Power Klystrons: Theory and Practice at the Stanford Linear Accelerator CenterPart I
Caryotakis, G.
2004-12-15T23:59:59.000Z
This is Part I of a two-part report on design and manufacturing methods used at SLAC to produce accelerator klystrons. Chapter 1 begins with the history and applications for klystrons, in both of which Stanford University was extensively involved. The remaining chapters review the theory of klystron operation, derive the principal formulae used in their design, and discuss the assumptions that they involve. These formulae are subsequently used in small-signal calculations of the frequency response of a particular klystron, whose performance is also simulated by two different computer codes. The results of calculations and simulations are compared to the actual performance of the klystron.
Kreitzer, B R; Houck, T L; Luchterhand, O C
2011-07-19T23:59:59.000Z
This paper addresses thermal drift in sodium thiosulfate liquid resistors and their replacement with linear disk resistors from HVR Advanced Power Components. Sodium thiosulfate resistors in the FXR induction linear accelerator application have a temperature coefficient of {approx}1.8%/C. The FXR Marx banks send an 8kJ pulse through eight 524 cm{sup 3} liquid resistors at a repetition rate of up to 1 every 45 seconds. Every pulse increases the temperature of the solution by {approx}0.4 C which produces a 0.7% change in resistance. The typical cooling rate is {approx}0.4 C per minute which results in {approx}0.1% energy drop per pulse during continuous pulsed operations. A radiographic accelerator is extraordinarily sensitive to energy variations. Changes in beam energy produce movement in beam transport, changes in spot size, and large dose variations. If self-heating were the only problem, we could predict the increase in input voltage required to compensate for the energy loss. However, there are other variables that influence the temperature of the resistors such as focus magnet heating, changes in room temperature, changes in cooling water, where the cell is located, etc. Additionally not all of the resistors have equivalent cooling rates and as many as 32 resistors are driven from a single power source. The FXR accelerator group elected to replace the sodium thiosulfate resistors with HVR Linear Disk Resistors in a stack type configuration. With data limited for these resistors when used in oil and at low resistance values, a full characterization needed to be performed. High currents (up to 15kA), high voltages (up to 400kV), and Fast Rise times (<10ns) made a resistor choice difficult. Other solid resistors have been tried and had problems at the connection points and with the fact that the resistivity changed as they absorbed oil. The selected HVR resistors have the advantage of being manufactured with the oil impregnated in to them so this characteristic is minimized while still offering the desired low temperature coefficient of resistance compared to sodium thiosulfate. The characterization experiments and comparison with the sodium thiosulfate liquid resistors will be fully discussed and the final design described.
Lee, Shiu-Hang; Kamae, Tuneyoshi; Ellison, Donald C.
2008-07-02T23:59:59.000Z
We present a 3-dimensional model of supernova remnants (SNRs) where the hydrodynamical evolution of the remnant is modeled consistently with nonlinear diffusive shock acceleration occurring at the outer blast wave. The model includes particle escape and diffusion outside of the forward shock, and particle interactions with arbitrary distributions of external ambient material, such as molecular clouds. We include synchrotron emission and cooling, bremsstrahlung radiation, neutral pion production, inverse-Compton (IC), and Coulomb energy-loss. Boardband spectra have been calculated for typical parameters including dense regions of gas external to a 1000 year old SNR. In this paper, we describe the details of our model but do not attempt a detailed fit to any specific remnant. We also do not include magnetic field amplification (MFA), even though this effect may be important in some young remnants. In this first presentation of the model we don't attempt a detailed fit to any specific remnant. Our aim is to develop a flexible platform, which can be generalized to include effects such as MFA, and which can be easily adapted to various SNR environments, including Type Ia SNRs, which explode in a constant density medium, and Type II SNRs, which explode in a pre-supernova wind. When applied to a specific SNR, our model will predict cosmic-ray spectra and multi-wavelength morphology in projected images for instruments with varying spatial and spectral resolutions. We show examples of these spectra and images and emphasize the importance of measurements in the hard X-ray, GeV, and TeV gamma-ray bands for investigating key ingredients in the acceleration mechanism, and for deducing whether or not TeV emission is produced by IC from electrons or pion-decay from protons.
Sheng Ke [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States)]. E-mail: ks2mc@virginia.edu; Molloy, Janelle A. [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States); Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Read, Paul W. [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States)
2006-07-01T23:59:59.000Z
Purpose: To date, most intensity-modulated radiation therapy (IMRT) delivery has occurred using linear accelerators (linacs), although helical tomotherapy has become commercially available. To quantify the dosimetric difference, we compared linac-based and helical tomotherapy-based treatment plans for IMRT of the oropharynx. Methods and Materials: We compared the dosimetry findings of 10 patients who had oropharyngeal carcinoma. Five patients each had cancers in the base of the tongue and tonsil. Each plan was independently optimized using either the CORVUS planning system (Nomos Corporation, Sewickly, PA), commissioned for a Varian 2300 CD linear accelerator (Varian Medical Systems, Palo Alto, CA) with 1-cm multileaf collimator leaves, or helical tomotherapy. The resulting treatment plans were evaluated by comparing the dose-volume histograms, equivalent uniform dose (EUD), dose uniformity, and normal tissue complication probabilities. Results: Helical tomotherapy plans showed improvement of critical structure avoidance and target dose uniformity for all patients. The average equivalent uniform dose reduction for organs at risk (OARs) surrounding the base of tongue and the tonsil were 17.4% and 27.14% respectively. An 80% reduction in normal tissue complication probabilities for the parotid glands was observed in the tomotherapy plans relative to the linac-based plans. The standard deviation of the planning target volume dose was reduced by 71%. In our clinic, we use the combined dose-volume histograms for each class of plans as a reference goal for helical tomotherapy treatment planning optimization. Conclusions: Helical tomotherapy provides improved dose homogeneity and normal structure dose compared with linac-based IMRT in the treatment of oropharyngeal carcinoma resulting in a reduced risk for complications from focal hotspots within the planning target volume and for the adjacent parotid glands.
Sufficient statistics for linear control strategies in decentralized systems with partial history
Mahajan, Aditya
1 Sufficient statistics for linear control strategies in decentralized systems with partial history sharing Aditya Mahajan and Ashutosh Nayyar Abstract In decentralized control systems with linear dynamics, quadratic cost, and Gaussian disturbance (also called decentralized LQG systems) linear control strategies
Alternative linear structures for classical and quantum systems
E. Ercolessi; A. Ibort; G. Marmo; G. Morandi
2007-06-12T23:59:59.000Z
The possibility of deforming the (associative or Lie) product to obtain alternative descriptions for a given classical or quantum system has been considered in many papers. Here we discuss the possibility of obtaining some novel alternative descriptions by changing the linear structure instead. In particular we show how it is possible to construct alternative linear structures on the tangent bundle TQ of some classical configuration space Q that can be considered as "adapted" to the given dynamical system. This fact opens the possibility to use the Weyl scheme to quantize the system in different non equivalent ways, "evading", so to speak, the von Neumann uniqueness theorem.
Optical Effects of Wakefields in the PEP-II Stanford Linear Accelerator Center B Factory
Heifets, S.; Novokhatski, S.; Teytelman, D.; /SLAC
2007-01-29T23:59:59.000Z
Wakefields defining beam stability affect also the beam optics and beam properties in high current machines. In this paper we present observations and analysis of the optical effects in the PEP-II SLAC B-factory, which has the record in achievement of high electron and positron currents. We study the synchronous phase and the bunch length variation along the train of bunches, overall bunch lengthening and effects of the wakes on the tune and on the Twiss parameters. This analysis is being used in upgrades of PEP-II and may be applied to future B-factories and damping rings for Linear Colliders.
Energy and linear and angular momenta in simple electromagnetic systems
Mansuripur, Masud
2015-01-01T23:59:59.000Z
We present examples of simple electromagnetic systems in which energy, linear momentum, and angular momentum exhibit interesting behavior. The systems are sufficiently simple to allow exact solutions of Maxwell's equations in conjunction with the electrodynamic laws of force, torque, energy, and momentum. In all the cases examined, conservation of energy and momentum is confirmed.
Optimization on linear matrix inequalities for polynomial systems control
Paris-Sud XI, Université de
Optimization on linear matrix inequalities for polynomial systems control Didier Henrion1,2 Draft Many problems of systems control theory boil down to solving polynomial equations, polynomial conclude this part with applications to optimal control (design of a trajectory optimal w.r.t. a given
Models of f(R) Cosmic Acceleration that Evade Solar-System Tests
Wayne Hu; Ignacy Sawicki
2007-05-08T23:59:59.000Z
We study a class of metric-variation f(R) models that accelerates the expansion without a cosmological constant and satisfies both cosmological and solar-system tests in the small-field limit of the parameter space. Solar-system tests alone place only weak bounds on these models, since the additional scalar degree of freedom is locked to the high-curvature general-relativistic prediction across more than 25 orders of magnitude in density, out through the solar corona. This agreement requires that the galactic halo be of sufficient extent to maintain the galaxy at high curvature in the presence of the low-curvature cosmological background. If the galactic halo and local environment in f(R) models do not have substantially deeper potentials than expected in LCDM, then cosmological field amplitudes |f_R| > 10^{-6} will cause the galactic interior to evolve to low curvature during the acceleration epoch. Viability of large-deviation models therefore rests on the structure and evolution of the galactic halo, requiring cosmological simulations of f(R) models, and not directly on solar-system tests. Even small deviations that conservatively satisfy both galactic and solar-system constraints can still be tested by future, percent-level measurements of the linear power spectrum, while they remain undetectable to cosmological-distance measures. Although we illustrate these effects in a specific class of models, the requirements on f(R) are phrased in a nearly model-independent manner.
Optimal Unravellings for Feedback Control in Linear Quantum Systems
H. M . Wiseman; A. C. Doherty
2005-02-26T23:59:59.000Z
For quantum systems with linear dynamics in phase space much of classical feedback control theory applies. However, there are some questions that are sensible only for the quantum case, such as: given a fixed interaction between the system and the environment what is the optimal measurement on the environment for a particular control problem? We show that for a broad class of optimal (state-based) control problems (the stationary Linear-Quadratic-Gaussian class), this question is a semi-definite program. Moreover, the answer also applies to Markovian (current-based) feedback.
Equivalence of Control Systems with Linear Systems on Lie Groups and Homogeneous Spaces
Paris-Sud XI, Université de
Equivalence of Control Systems with Linear Systems on Lie Groups and Homogeneous Spaces Philippe of geometric control theory arguments. Keywords: Lie groups; Homogeneous spaces; Linear systems; Com- plete JOUAN 28th November 2008 Abstract The aim of this paper is to prove that a control affine system
Koutsoukos, Xenofon D.
Design of Stabilizing Switching Control Laws for Discrete and Continuous-Time Linear Systems Using Piecewise-Linear Lyapunov Functions Xenofon D. Koutsoukos Palo Alto Research Center 3333 Coyote Hill Road-219-631-5792 Fax +1-219-631-4393 antsaklis.1@nd.edu Abstract In this paper, the stability of switched linear
RELWAY: a process data highway system optimized for accelerators
Frankel, R.; Buxton, W,; Kohler, K.; Warkentien, R.; White, A.
1981-01-01T23:59:59.000Z
The command/control scheme for the Isabelle accelerator, specifically the process data highway are discussed. (GHT)J
Denis, Daniel (Daniel B.)
2009-01-01T23:59:59.000Z
In Inertial Confinement Fusion (ICF) research, passive detection systems are often required in several applications for observing fusion-product spectra from an ICF-capsule implosion. These detection devices can be calibrated ...
Complex geometric optics for symmetric hyperbolic systems I: linear theory
Omar Maj
2008-02-12T23:59:59.000Z
We obtain an asymptotic solution for $\\ep \\to 0$ of the Cauchy problem for linear first-order symmetric hyperbolic systems with oscillatory initial values written in the eikonal form of geometric optics with frequency $1/\\ep$, but with complex phases. For the most common linear wave propagation models, this kind on Cauchy problems are well-known in the applied literature and their asymptotic theory, referred to as complex geometric optics, is attracting interest for applications. In this work, which is the first of a series of papers dedicated to complex geometric optics for nonlinear symmetric hyperbolic systems, we develop a rigorous linear theory and set the basis for the subsequent nonlinear analysis.
Termination of Narrowing in Left-Linear Constructor Systems
Vidal, Germán
[24], partial evaluation [1, 48], refining methods for proving the termination of rewriting [8, 9Termination of Narrowing in Left-Linear Constructor Systems Germ´an Vidal Technical University.g., it forms the basis of functional logic languages). Surprisingly, the termination of narrowing has been
Termination of Narrowing in Left-Linear Constructor Systems
Vidal, Germán
], model checking [17], partial evaluation [1, 32], refining methods for proving the terminationTermination of Narrowing in Left-Linear Constructor Systems Germ´an Vidal Technical University in different contexts, ranging from the- orem proving to language design. Surprisingly, the termination of nar
Multipole-based preconditioners for large sparse linear systems
Sarin, Vivek
Multipole-based preconditioners for large sparse linear systems Sreekanth R. Sambavaram a,1 , Vivek and hierarchical multipole approximations, the cost of computing and storing these preconditioners has reduced drama- tically. This paper describes the use of multipole operators as parallel preconditioners
cryogenic units, resulting in 2.5 km long beam vacuum sections. There is considerable concern, that due - the beam vacuum and a separate input coupler vacuum; the other separates the input coupler vac- uum from the wave guide, which is supposedly filled with nitrogen or dry air. The beam vacuum systems at both sides
Design and performance of the Stanford Linear Collider Control System
Melen, R.E.
1984-10-01T23:59:59.000Z
The success of the Stanford Linear Collider (SLC) will be dependent upon the implementation of a very large advanced computer-based instrumentation and control system. This paper describes the architectural design of this system as well as a critique of its performance. This critique is based on experience obtained from its use in the control and monitoring of 1/3 of the SLAC linac and in support of an expensive experimental machine physics experimental program. 11 references, 3 figures.
RFQ (radio-frequency quadrupole) accelerator tuning system
Bolie, V.W.
1988-04-12T23:59:59.000Z
A cooling system is provided for maintaining a preselected operating temperature in a device, which may be an RFQ accelerator, having a variable heat removal requirement, by circulating a cooling fluid through a cooling system remote from the device. Internal sensors in the device enable an estimated error signal to be generated from parameters which are indicative of the heat removal requirement from the device. Sensors are provided at predetermined locations in the cooling system for outputting operational temperature signals. Analog and digital computers define a control signal functionally related to the temperature signals and the estimated error signal, where the control signal is defined effective to return the device to the preselected operating temperature in a stable manner. The cooling system includes a first heat sink responsive to a first portion of the control signal to remove heat from a major portion of the circulating fluid. A second heat sink is responsive to a second portion of the control to remove heat from a minor portion of the circulating fluid. The cooled major and minor portions of the circulating fluid are mixed in responsive to a mixing portion of the control signal, which is effective to proportion the major and minor portions of the circulating fluid to establish a mixed fluid temperature which is effective to define the preselected operating temperature for the remote device. 3 figs., 2 tabs.
POLE EXPANSION FOR SOLVING A TYPE OF PARAMETRIZED LINEAR SYSTEMS IN ELECTRONIC STRUCTURE
Ying, Lexing
POLE EXPANSION FOR SOLVING A TYPE OF PARAMETRIZED LINEAR SYSTEMS IN ELECTRONIC STRUCTURE, parametrized linear systems, electronic structure calculation AMS subject classifications. 65F30,65D30,65Z05 1 linear systems. Under certain assumptions on the parametrization, solutions to the linear systems for all
Modified Accelerated Cost-Recovery System (MACRS) + Bonus Depreciation (2008-2012)
Broader source: Energy.gov [DOE]
Under the federal Modified Accelerated Cost-Recovery System (MACRS), businesses may recover investments in certain property through depreciation deductions. The MACRS establishes a set of class...
Energy absorption by "sparse" systems: beyond linear response theory
Doron Cohen
2013-01-21T23:59:59.000Z
The analysis of the response to driving in the case of weakly chaotic or weakly interacting systems should go beyond linear response theory. Due to the "sparsity" of the perturbation matrix, a resistor network picture of transitions between energy levels is essential. The Kubo formula is modified, replacing the "algebraic" average over the squared matrix elements by a "resistor network" average. Consequently the response becomes semi-linear rather than linear. Some novel results have been obtained in the context of two prototype problems: the heating rate of particles in Billiards with vibrating walls; and the Ohmic Joule conductance of mesoscopic rings driven by electromotive force. Respectively, the obtained results are contrasted with the "Wall formula" and the "Drude formula".
Diamant, Kevin David; Raitses, Yevgeny; Fisch, Nathaniel Joseph
2014-05-13T23:59:59.000Z
Systems and methods may be provided for cylindrical Hall thrusters with independently controllable ionization and acceleration stages. The systems and methods may include a cylindrical channel having a center axial direction, a gas inlet for directing ionizable gas to an ionization section of the cylindrical channel, an ionization device that ionizes at least a portion of the ionizable gas within the ionization section to generate ionized gas, and an acceleration device distinct from the ionization device. The acceleration device may provide an axial electric field for an acceleration section of the cylindrical channel to accelerate the ionized gas through the acceleration section, where the axial electric field has an axial direction in relation to the center axial direction. The ionization section and the acceleration section of the cylindrical channel may be substantially non-overlapping.
Coherent versus measurement feedback: Linear systems theory for quantum information
Naoki Yamamoto
2014-10-10T23:59:59.000Z
To control a quantum system via feedback, we generally have two options in choosing control scheme. One is the coherent feedback, which feeds the output field of the system, through a fully quantum device, back to manipulate the system without involving any measurement process. The other one is the measurement-based feedback, which measures the output field and performs a real-time manipulation on the system based on the measurement results. Both schemes have advantages/disadvantages, depending on the system and the control goal, hence their comparison in several situation is important. This paper considers a general open linear quantum system with the following specific control goals; back-action evasion (BAE), generation of a quantum non-demolished (QND) variable, and generation of a decoherence-free subsystem (DFS), all of which have important roles in quantum information science. Then some no-go theorems are proven, clarifying that those goals cannot be achieved by any measurement-based feedback control. On the other hand it is shown that, for each control goal, there exists a coherent feedback controller accomplishing the task. The key idea to obtain all the results is system theoretic characterizations of BAE, QND, and DFS in terms of controllability and observability properties or transfer functions of linear systems, which are consistent with their standard definitions.
Forno, Massimo Dal [Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Trieste (Italy) [Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Trieste (Italy); Department of Engineering and Architecture, University of Trieste, Trieste (Italy); Craievich, Paolo [Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Trieste (Italy) [Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Trieste (Italy); P.S.I. (Paul Scherrer Institute), Villigen (Switzerland); Penco, Giuseppe [Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Trieste (Italy)] [Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Trieste (Italy); Vescovo, Roberto [Department of Engineering and Architecture, University of Trieste, Trieste (Italy)] [Department of Engineering and Architecture, University of Trieste, Trieste (Italy)
2013-11-15T23:59:59.000Z
The front-end injection systems of the FERMI@Elettra linac produce high brightness electron beams that define the performance of the Free Electron Laser. The photoinjector mainly consists of the radiofrequency (rf) gun and of two S-band rf structures which accelerate the beam. Accelerating structures endowed with a single feed coupler cause deflection and degradation of the electron beam properties, due to the asymmetry of the electromagnetic field. In this paper, a new type of single feed structure with movable short-circuit is proposed. It has the advantage of having only one waveguide input, but we propose a novel design where the dipolar component is reduced. Moreover, the racetrack geometry allows to reduce the quadrupolar component. This paper presents the microwave design and the analysis of the particle motion inside the linac. A prototype has been machined at the Elettra facility to verify the new coupler design and the rf field has been measured by adopting the bead-pull method. The results are here presented, showing good agreement with the expectations.
Controller Synthesis for a class of Uncertain Piecewise Linear Hybrid Dynamical Systems 1
Sontag, Eduardo
Controller Synthesis for a class of Uncertain Piecewise Linear Hybrid Dynamical Systems 1 Hai Lin2, observability and controllability etc. Piecewise linear systems arise often from linearization of nonlinear systems1 . Here we consider the controller synthesis problem for uncertain piecewise linear hybrid dynami
Transmutation of nuclear waste in accelerator-driven systems
Herrera-Martínez, A
2004-01-01T23:59:59.000Z
Today more than ever energy is not only a cornerstone of human development, but also a key to the environmental sustainability of economic activity. In this context, the role of nuclear power may be emphasized in the years to come. Nevertheless, the problems of nuclear waste, safety and proliferation still remain to be solved. It is believed that the use of accelerator-driven systems (ADSs) for nuclear waste transmutation and energy production would address these problems in a simple, clean and economically viable, and therefore sustainable, manner. This thesis covers the major nuclear physics aspects of ADSs, in particular the spallation process and the core neutronics specific to this type of systems. The need for accurate nuclear data is described, together with a detailed analysis of the specific isotopes and energy ranges in which this data needs to be improved and the impact of their uncertainty. Preliminary experimental results for some of these isotopes, produced by the Neutron Time-of-Flight (n_TOF) ...
Elena Amato; Pasquale Blasi
2006-06-23T23:59:59.000Z
Particle acceleration at astrophysical shocks may be very efficient if magnetic scattering is self-generated by the same particles. This nonlinear process adds to the nonlinear modification of the shock due to the dynamical reaction of the accelerated particles on the shock. Building on a previous general solution of the problem of particle acceleration with arbitrary diffusion coefficients (Amato & Blasi, 2005), we present here the first semi-analytical calculation of particle acceleration with both effects taken into account at the same time: charged particles are accelerated in the background of Alfven waves that they generate due to the streaming instability, and modify the dynamics of the plasma in the shock vicinity.
The effect of a paraffin screen on the neutron dose at the maze door of a 15 MV linear accelerator
Krmar, M.; Kuzmanovi?, A. [Physics Department, Faculty of Science, University of Novi Sad, Novi Sad 21000 (Serbia)] [Physics Department, Faculty of Science, University of Novi Sad, Novi Sad 21000 (Serbia); Nikoli?, D. [National Institute for Nanotechnology, Edmonton, Alberta T6G 2M9 (Canada)] [National Institute for Nanotechnology, Edmonton, Alberta T6G 2M9 (Canada); Kuzmanovi?, Z. [International Medical Centers, Banja Luka 78000, Republika Srpska, Bosnia and Herzegovina (Bosnia and Herzegowina)] [International Medical Centers, Banja Luka 78000, Republika Srpska, Bosnia and Herzegovina (Bosnia and Herzegowina); Ganezer, K. [Physics Department, California State University Dominguez Hills, Carson, California 90747 (United States)] [Physics Department, California State University Dominguez Hills, Carson, California 90747 (United States)
2013-08-15T23:59:59.000Z
Purpose: The purpose of this study was to explore the effects of a paraffin screen located at various positions in the maze on the neutron dose equivalent at the maze door.Methods: The neutron dose equivalent was measured at the maze door of a room containing a 15 MV linear accelerator for x-ray therapy. Measurements were performed for several positions of the paraffin screen covering only 27.5% of the cross-sectional area of the maze. The neutron dose equivalent was also measured at all screen positions. Two simple models of the neutron source were considered in which the first assumed that the source was the cross-sectional area at the inner entrance of the maze, radiating neutrons in an isotropic manner. In the second model the reduction in the neutron dose equivalent at the maze door due to the paraffin screen was considered to be a function of the mean values of the neutron fluence and energy at the screen.Results: The results of this study indicate that the equivalent dose at the maze door was reduced by a factor of 3 through the use of a paraffin screen that was placed inside the maze. It was also determined that the contributions to the dosage from areas that were not covered by the paraffin screen as viewed from the dosimeter, were 2.5 times higher than the contributions from the covered areas. This study also concluded that the contributions of the maze walls, ceiling, and floor to the total neutron dose equivalent were an order of magnitude lower than those from the surface at the far end of the maze.Conclusions: This study demonstrated that a paraffin screen could be used to reduce the neutron dose equivalent at the maze door by a factor of 3. This paper also found that the reduction of the neutron dose equivalent was a linear function of the area covered by the maze screen and that the decrease in the dose at the maze door could be modeled as an exponential function of the product ?·E at the screen.
Feasibility Study of Accelerator Driven System Proposed by JAEA
Sugawara, Takanori; Nishihara, Kenji; Tsujimoto, Kazufumi; Iwanaga, Kohei; Kurata, Yuji; Sasa, Toshinobu; Oigawa, Hiroyuki [Japan Atomic Energy Agency: 2-4 Shirakata-shirane Tokai-Mura, Ibaraki, 319-1195 (Japan)
2007-07-01T23:59:59.000Z
Accelerator Driven System (ADS) has been studied to transmute minor actinides (MA) discharged from spent fuel of commercial nuclear power plants. In Japan Atomic Energy Agency (JAEA), various R and D for an 800 MWt, lead bismuth eutectic (LBE) cooled ADS have been performed. The feasibility for the ADS is discussed in the present study in terms of the neutronics design, the safety analysis and the design of the beam window. In the neutronics design, the maximum temperature at the surface of the fuel pin was decreased from 578 deg. C to 498 deg. C by the adjustment of the ZrN inert matrix ratio for four zones. In the safety analysis, it was confirmed that there was very little possibility of core disruptive accidents at unprotected accidents in the ADS proposed by JAEA. For the design of the beam window, the parametric survey for the buckling failure was performed to discuss the methods to increase the margin for the buckling pressure. (authors)
Muon Acceleration - RLA and FFAG
Alex Bogacz
2011-10-01T23:59:59.000Z
Various acceleration schemes for muons are presented. The overall goal of the acceleration systems: large acceptance acceleration to 25 GeV and 'beam shaping' can be accomplished by various fixed field accelerators at different stages. They involve three superconducting linacs: a single pass linear Pre-accelerator followed by a pair of multi-pass Recirculating Linear Accelerators (RLA) and finally a non-scaling FFAG ring. The present baseline acceleration scenario has been optimized to take maximum advantage of appropriate acceleration scheme at a given stage. The solenoid based Pre-accelerator offers very large acceptance and facilitates correction of energy gain across the bunch and significant longitudinal compression trough induced synchrotron motion. However, far off-crest acceleration reduces the effective acceleration gradient and adds complexity through the requirement of individual RF phase control for each cavity. The RLAs offer very efficient usage of high gradient superconducting RF and ability to adjust path-length after each linac pass through individual return arcs with uniformly periodic FODO optics suitable for chromatic compensation of emittance dilution with sextupoles. However, they require spreaders/recombiners switchyards at both linac ends and significant total length of the arcs. The non-scaling Fixed Field Alternating Gradient (FFAG) ring combines compactness with very large chromatic acceptance (twice the injection energy) and it allows for large number of passes through the RF (at least eight, possibly as high as 15).
One-electron linear systems in a strong magnetic field
J. C. Lopez V.; A. Turbiner
2000-01-19T23:59:59.000Z
Using a variational method we study a sequence of the one-electron atomic and molecular-type systems H, H_2^+, H_3^(2+) and H_4^(3+) in the presence of a homogeneous magnetic field ranging B = 0 - 4.414x10^{13} G. These systems are taken as a linear configuration aligned with the magnetic lines. For H_3^(2+) the potential energy surface has a minimum for B\\sim 10^{11} G which deepens with growth of the magnetic field strength (JETP Lett. 69, 844 (1999)); for B \\gtrsim 10^{12} G the minimum of the potential energy surface becomes sufficiently deep to have longitudinal vibrational state. We demonstrate that for the (ppppe) system the potential energy surface at B \\gtrsim 4.414x10^{13} G develops a minimum, indicating the possible existence of exotic molecular ion H_4^(3+). We find that for almost all accessible magnetic fields H_2^+ is the most bound one-electron linear system while for magnetic fields B \\gtrsim 10^{13} G the molecular ion H_3^(2+) becomes the most bound.
Compact accelerator for medical therapy
Caporaso, George J.; Chen, Yu-Jiuan; Hawkins, Steven A.; Sampayan, Stephen E.; Paul, Arthur C.
2010-05-04T23:59:59.000Z
A compact accelerator system having an integrated particle generator-linear accelerator with a compact, small-scale construction capable of producing an energetic (.about.70-250 MeV) proton beam or other nuclei and transporting the beam direction to a medical therapy patient without the need for bending magnets or other hardware often required for remote beam transport. The integrated particle generator-accelerator is actuable as a unitary body on a support structure to enable scanning of a particle beam by direction actuation of the particle generator-accelerator.
The thermodynamic dual structure of linear-dissipative driven systems
Eric Smith
2005-05-02T23:59:59.000Z
The spontaneous emergence of dynamical order, such as persistent currents, is sometimes argued to require principles beyond the entropy maximization of the second law of thermodynamics. I show that, for linear dissipation in the Onsager regime, current formation can be driven by exactly the Jaynesian principle of entropy maximization, suitably formulated for extended systems and nonequilibrium boundary conditions. The Legendre dual structure of equilibrium thermodynamics is also preserved, though it requires the admission of current-valued state variables, and their correct incorporation in the entropy.
A RECIPE FOR LINEAR COLLIDER FINAL FOCUS SYSTEM DESIGN
Seryi, Andrei
2003-05-27T23:59:59.000Z
The design of Final Focus systems for linear colliders is challenging because of the large demagnifications needed to produce nanometer-sized beams at the interaction point. Simple first- and second-order matrix matching have proven insufficient for this task, and minimization of third- and higher-order aberrations is essential. An appropriate strategy is required for the latter to be successful. A recipe for Final Focus design, and a set of computational tools used to implement this approach, are described herein. An example of the use of this procedure is given.
Schachinger, L.C.
2011-01-01T23:59:59.000Z
and Controlling Accelerator Physics Parameters at theLight Source for accelerator physics studies and accelerator
Yu Qi; Xu Tao Guang
2002-01-01T23:59:59.000Z
As a prior option of the next generation of energy source, the accelerator driven subcritical nuclear power system (ADS) can use efficiently the uranium and thorium resource, transmute the high-level long-lived radioactive wastes and raise nuclear safety. The ADS accelerator should provide the proton beam with tens megawatts. The superconducting linac (SCL) is a good selection of ADS accelerator because of its high efficiency and low beam loss rate. It is constitute by a series of the superconducting accelerating cavities. The cavity geometry is determined by means of the electromagnetic field computation. The SCL main parameters are determined by the particle dynamics computation
Designing Accelerator-Based Distributed Systems for High Performance M. Mustafa Rafique, Ali R. Butt
Butt, Ali R.
), yielding highly power-efficient and cost-efficient designs, with per- formance exceeding 100 Gflops [1Designing Accelerator-Based Distributed Systems for High Performance M. Mustafa Rafique, Ali R general- purpose cores (e.g. x86, PowerPC) and computational accelerators (e.g. SIMD processors and GPUs
BYPASS SYSTEM FOR SHUNTING OF ELECTROMAGNETS FOR ACCELERATORS AND STORAGE RINGS
Kozak, Victor R.
BYPASS SYSTEM FOR SHUNTING OF ELECTROMAGNETS FOR ACCELERATORS AND STORAGE RINGS O. Belikov, A accelerators and charge particle storage rings faces the problem of placement of detached elements for magnetic should be a 1F capacitance battery for the main magnet; voltage across the magnet to be bypassed
AT2 DS II - Accelerator System Design (Part II) - CCC Video Conference
None
2011-10-06T23:59:59.000Z
Discussion Session - Accelerator System Design (Part II) Tutors: C. Darve, J. Weisend II, Ph. Lebrun, A. Dabrowski, U. Raich Video Conference with the CERN Control Center. Experts in the field of Accelerator science will be available to answer the students questions. This session will link the CCC and SA (using Codec VC).
Limited Model Information Control Design for Linear Discrete-Time Systems with Stochastic Parameters
Johansson, Karl Henrik
Limited Model Information Control Design for Linear Discrete-Time Systems with Stochastic systems with stochastically varying parameters. Recently, there have been studies in optimal control subsystems' parameters. There have been many studies in optimal control design for linear discrete
Uniform Stability of Switched Linear Systems: Extensions of LaSalle's Invariance Principle
Liebling, Michael
1 Uniform Stability of Switched Linear Systems: Extensions of LaSalle's Invariance Principle Jo linear systems, where uniformity refers to the con- vergence rate of the multiple solutions that one be viewed as extensions of LaSalle's Invariance Principle to certain classes of switched linear systems
Exploiting the Eigenstructure of Linear Systems to speed up Reachability Computations
Fanchon, Eric
Exploiting the Eigenstructure of Linear Systems to speed up Reachability Computations Alexandre computations of linear systems. Furthemore, it can be applied to improve the time-efficiency of the dynamic. In this paper, we propose a method exploiting the eigenstructure of a linear continuous system to efficiently
OFS model-based adaptive control for block-oriented non-linear Systems
Cambridge, University of
-type non-linear systems (Go´mez and Baeyens, 2004; Henson, 1997). Wiener-type systems consist of a linear the same elements in reverse order (Go´mez and Baeyens, 2004). In recent years, the control of these types of systems has become one of the most important and difficult tasks in non-linear control field (Go´mez
Mahajan, Aditya
1 Sufficient statistics for linear control strategies in decentralized systems with partial history sharing Aditya Mahajan and Ashutosh Nayyar Abstract--In decentralized control systems with linear dy- namics, quadratic cost, and Gaussian disturbance (also called decentralized LQG systems) linear control
Offset-free Receding Horizon Control of Constrained Linear Systems subject to
Cambridge, University of
Offset-free Receding Horizon Control of Constrained Linear Systems subject to Time/F-INFENG/TR.468 November 4, 2003 #12;Offset-free Receding Horizon Control of Constrained Linear Systems subject and offset-free control of con- strained, linear time-invariant systems in the presence of time
A New Book "NUMERICAL METHODS FOR LINEAR CONTROL SYSTEMS DESIGN AND ANALYSIS"
Datta, Biswa
A New Book "NUMERICAL METHODS FOR LINEAR CONTROL SYSTEMS DESIGN AND ANALYSIS" by Biswa Nath Datta I am pleased to announce publication of my book: "Numerical Methods for Linear Control Systems Design-of-the-art computationally viable algorithms for major tasks arising in linear control systems design and analysis
Tube-based distributed control of linear constrained systems Stefano Riverso a
Ferrari-Trecate, Giancarlo
Tube-based distributed control of linear constrained systems Stefano Riverso a , Giancarlo Ferrari in [20] for linear systems and aim at approximating centralized MPC controllers. However, they require, 27100 Pavia, Italy Abstract In this paper we consider a linear system structured into physically coupled
A General Result on the Stabilization of Linear Systems Using Bounded Controls 1
Sontag, Eduardo
A General Result on the Stabilization of Linear Systems Using Bounded Controls 1 H'ector J of controllers that globally stabilize linear systems subject to control saturation. We allow essentially words: linear systems, saturated actuators, bounded controls, neural nets October, 1992. Revised
OPTIMAL REGULATOR FOR LINEAR SYSTEMS WITH TIME DELAY IN CONTROL INPUT
OPTIMAL REGULATOR FOR LINEAR SYSTEMS WITH TIME DELAY IN CONTROL INPUT MICHAEL BASIN JESUS RODRIGUEZ are included. Keywords: Linear Time-Delay System; Optimal Control; Filtering Category of the paper: Regular 1 Introduction Although the optimal control (regulator) problem for linear system states was solved, as well
An LQ sub-optimal stabilizing feedback law for switched linear systems
Paris-Sud XI, Université de
An LQ sub-optimal stabilizing feedback law for switched linear systems P. Riedinger J.-C. Vivalda linear switched system based on the optimization of a quadratic criterion. The main result provides is a challenging task. LQ regulators are widely used for the control of linear systems because of their simple
Application of JLab 12GeV helium refrigeration system for the FRIB accelerator at MSU
Ganni, V.; Knudsen, P.; Arenius, D. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Casagrande, F. [MSU-FRIB, East Lansing, MI 48824 (United States)
2014-01-29T23:59:59.000Z
The planned approach to have a turnkey helium refrigeration system for the MSU-FRIB accelerator system, encompassing the design, fabrication, installation and commissioning of the 4.5-K refrigerator cold box(es), cold compression system, warm compression system, gas management, oil removal and utility/ancillary systems, was found to be cost prohibitive. Following JLab’s suggestion, MSU-FRIB accelerator management made a formal request to evaluate the applicability of the recently designed 12GeV JLab cryogenic system for this application. The following paper will outline the findings and the planned approach for the FRIB helium refrigeration system.
Application of JLab 12GeV helium refrigeration system for the FRIB accelerator at MSU
Ganni, Venkatarao [JLAB; Knudsen, Peter N. [JLAB; Arenius, Dana M. [JLAB; Casagrande, Fabio [Michigan State University
2014-01-01T23:59:59.000Z
The planned approach to have a turnkey helium refrigeration system for the MSU-FRIB accelerator system, encompassing the design, fabrication, installation and commissioning of the 4.5-K refrigerator cold box(es), cold compression system, warm compression system, gas management, oil removal and utility/ancillary systems, was found to be cost prohibitive. Following JLab’s suggestion, MSU-FRIB accelerator management made a formal request to evaluate the applicability of the recently designed 12GeV JLab cryogenic system for this application. The following paper will outline the findings and the planned approach for the FRIB helium refrigeration system.
Cambridge, University of
Offset-free control of constrained linear discrete-time systems subject to persistent unmeasured, this objective is obtained by designing a dynamic, linear, time-invariant, offset-free controller, and an appropriate domain of attraction for this linear controller is defined. Following this, the linear
An algorithm to solve any tropical linear system $A\\odot x=B\\odot x$
Lorenzo, E
2010-01-01T23:59:59.000Z
An algorithm to solve any tropical linear system $A\\odot x=B\\odot x$ is presented. The given system is converted into two classical linear systems: a system of equations and a system of inequalities, each item (equation or inequality) involving exactly two variables, one with coefficient $1$, and another with coefficient $-1$. The two classical linear systems are solved, essentially, by triangulation and backward substitution.
Development of repetitive railgun pellet accelerator and steady-state pellet supply system
Oda, Y.; Onozuka, M.; Azuma, K. [Mitsubishi Heavy Industries, Ltd., Kobe (Japan); Kasai, S.; Hasegawa, K. [Japan Atomic Energy Research Inst., Naka (Japan)
1995-12-31T23:59:59.000Z
A railgun system for repetitive high-speed pellet acceleration and steady-state pellet supply system has been developed and investigated. Using a 2m-long railgun system, the hydrogen pellet was accelerated to 2.6km/sec by the supplied energy of 1.7kJ. It is expected that the hydrogen pellet can be accelerated to 3km/sec using the present pneumatic pellet accelerator and a 2m-long augment railgun. Screw-driven hydrogen-isotope filament extruding system has been fabricated and will be tested to examine its applicability to the steady-state extrusion of the solid hydrogen-isotope filament.
#12;COVER: Part of the drift-tube linear accelerator designed and built by Los Alamos National, Brookhaven, Jefferson, and Los Alamos. No single laboratory possessed the resources needed to design
Resource analysis of the quantum linear system algorithm
Artur Scherer; Benoît Valiron; Siun-Chuon Mau; Scott Alexander; Eric van den Berg; Thomas E. Chapuran
2015-05-25T23:59:59.000Z
We provide a detailed estimate for the logical resource requirements of the quantum linear system algorithm (QLSA) [Phys. Rev. Lett. 103, 150502 (2009)] including the recently described generalization [Phys. Rev. Lett. 110, 250504 (2013)]. Our resource estimates are based on the standard quantum-circuit model of quantum computation; they comprise circuit width, circuit depth, the number of qubits and ancilla qubits employed, and the overall number of elementary quantum gate operations as well as more specific gate counts for each elementary fault-tolerant gate from the standard set {X, Y, Z, H, S, T, CNOT}. To perform these estimates, we used an approach that combines manual analysis with automated estimates generated via the Quipper quantum programming language and compiler. Our estimates pertain to the example problem size N=332,020,680 beyond which, according to a crude big-O complexity comparison, QLSA is expected to run faster than the best known classical linear-system solving algorithm. For this problem size, a desired calculation accuracy 0.01 requires an approximate circuit width 340 and circuit depth of order $10^{25}$ if oracle costs are excluded, and a circuit width and depth of order $10^8$ and $10^{29}$, respectively, if oracle costs are included, indicating that the commonly ignored oracle resources are considerable. In addition to providing detailed logical resource estimates, it is also the purpose of this paper to demonstrate explicitly how these impressively large numbers arise with an actual circuit implementation of a quantum algorithm. While our estimates may prove to be conservative as more efficient advanced quantum-computation techniques are developed, they nevertheless provide a valid baseline for research targeting a reduction of the resource requirements, implying that a reduction by many orders of magnitude is necessary for the algorithm to become practical.
Conceptual study of high power proton linac for accelerator driven subcritical nuclear power system
Yu Qi; Ouyang Hua Fu; Xu Tao Guang
2001-01-01T23:59:59.000Z
As a prior option of the next generation of energy source, the accelerator driven subcritical nuclear power system (ADS) can use efficiently the uranium and thorium resource, transmute the high-level long-lived radioactive wastes and raise nuclear safety. The ADS accelerator should provide the proton beam with tens megawatts. The superconducting linac is a good selection of ADS accelerator because of its high efficiency and low beam loss rate. The ADS accelerator presented by the consists of a 5 MeV radio-frequency quadrupole, a 100 MeV independently phased superconducting cavity linac and a 1 GeV elliptical superconducting cavity linac. The accelerating structures and main parameters are determined and the research and development plan is considered
Formulae of Partial Reduction for Linear Systems of First Order Operator Equations
Branko Malesevic; Dragana Todoric; Ivana Jovovic; Sonja Telebakovic
2010-04-21T23:59:59.000Z
This paper deals with reduction of non-homogeneous linear systems of first order operator equations with constant coefficients. An equivalent reduced system, consisting of higher order linear operator equations having only one variable and first order linear operator equations in two variables, is obtained by using the rational canonical form.
On Topological Equivalence of Linear Flows with Applications to Bilinear Control Systems
Colonius, Fritz
On Topological Equivalence of Linear Flows with Applications to Bilinear Control Systems Victor theory for general linear ows. One of our main motivations comes from bilinear control systems, which This paper classi...es continuous linear ows using concepts and tech- niques from topological dynamics. Speci
LQG Control of Linear Systems with Network-Induced Varying Delay using the Delta Operator
LQG Control of Linear Systems with Network-Induced Varying Delay using the Delta Operator Masakazu be represented as a linear delay- depending feedback from the state and the previous control signal. Finally control of linear systems with long random time delays in delta domain is proposed in [22]. By using
Impulsive observer-based control for linear systems using irregularly sampled measurements
Paris-Sud XI, Université de
Impulsive observer-based control for linear systems using irregularly sampled measurements Y linear state feedback controller and an impulsive observer to provide an estimate the non-measured states, which are subsequently fed back in the control algorithm. We consider linear systems that can
ON LOCAL LINEARIZATION OF CONTROL SYSTEMS LAURENT BARATCHART AND JEAN-BAPTISTE POMET
Paris-Sud XI, Université de
ON LOCAL LINEARIZATION OF CONTROL SYSTEMS LAURENT BARATCHART AND JEAN-BAPTISTE POMET INRIA, B.P. 93-Baptiste.Pomet@sophia.inria.fr Abstract. We consider the problem of topological linearization of smooth (C or C) control systems, i u IRm , to be locally smoothly linearizable, i.e. locally equivalent to a control- lable linear
Offset-free control of constrained linear discrete-time systems subject to persistent
Cambridge, University of
Offset-free control of constrained linear discrete-time systems subject to persistent unmeasured-free control of constrained linear discrete-time systems subject to persistent unmeasured disturbances Gabriele Technical report CUED/F-INFENG/TR.466 September 10, 2003 #12;#12;Offset-free control of constrained linear
Event-triggered control with LQ optimality guarantees for saturated linear systems
Paris-Sud XI, Université de
Event-triggered control with LQ optimality guarantees for saturated linear systems A. Seuret , C of the domain of attraction. Keywords: event-based control, input saturation, linear quadratic performance 1 with event-triggered control algorithms for linear systems subject to plant input saturation. Hence, given
A General Result on the Stabilization of Linear Systems Using Bounded Controls1
Sontag, Eduardo
A General Result on the Stabilization of Linear Systems Using Bounded Controls1 HÂ´ector J. Sussmann that globally stabilize linear systems subject to control saturation. We allow essentially arbitrary saturation- braic) linear control theory, but are ubiquitous in control applications. To quote the recent textbook
Issues in the design of switched linear control systems: A benchmark study
Duffy, Ken
Issues in the design of switched linear control systems: A benchmark study Douglas Leith, Robert a tutorial overview of some of the issues that arise in the design of switched linear control systems, and issues concerning the realisation of switched linear controllers (and the associated transient response
Design of piecewise linear hybrid dynamical systems using a control regulator approach
Antsaklis, Panos
Design of piecewise linear hybrid dynamical systems using a control regulator approach X This paper presents a novel framework for hierarchical control of piecewise linear hybrid dynamical systems the continuous and the discrete part is defined by piecewise linear maps. Control design is formulated
Control of linear systems subject to input constraints: a polynomial approach. \\Lambda
Henrion, Didier
rely on the extended Farkas lemma [14], linear programming [32, 9], eigenstructure assignment [8, 9Control of linear systems subject to input constraints: a polynomial approach. \\Lambda Didier Republic Abstract A polynomial approach is pursued for locally stabilizing discretetime linear systems
Extending PowerPack for Profiling and Analysis of High Performance Accelerator-Based Systems
Li, Bo; Chang, Hung-Ching; Song, Shuaiwen; Su, Chun-Yi; Meyer, Timmy; Mooring, John; Cameron, Kirk
2014-12-01T23:59:59.000Z
Accelerators offer a substantial increase in efficiency for high-performance systems offering speedups for computational applications that leverage hardware support for highly-parallel codes. However, the power use of some accelerators exceeds 200 watts at idle which means use at exascale comes at a significant increase in power at a time when we face a power ceiling of about 20 megawatts. Despite the growing domination of accelerator-based systems in the Top500 and Green500 lists of fastest and most efficient supercomputers, there are few detailed studies comparing the power and energy use of common accelerators. In this work, we conduct detailed experimental studies of the power usage and distribution of Xeon-Phi-based systems in comparison to the NVIDIA Tesla and at SandyBridge.
H-Infinity Control of Linear Quantum Stochastic Systems
M. R. James; H. I. Nurdin; I. R. Petersen
2007-05-03T23:59:59.000Z
The purpose of this paper is to formulate and solve a H-infinity controller synthesis problem for a class of non-commutative linear stochastic systems which includes many examples of interest in quantum technology. The paper includes results on the class of such systems for which the quantum commutation relations are preserved (such a requirement must be satisfied in a physical quantum system). A quantum version of standard (classical) dissipativity results are presented and from this a quantum version of the Strict Bounded Real Lemma is derived. This enables a quantum version of the two Riccati solution to the H-infinity control problem to be presented. This result leads to controllers which may be realized using purely quantum, purely classical or a mixture of quantum and classical elements. This issue of physical realizability of the controller is examined in detail, and necessary and sufficient conditions are given. Our results are constructive in the sense that we provide explicit formulas for the Hamiltonian function and coupling operator corresponding to the controller.
Sarkar, B; Roy, S; Paul, S; Munshi, A; Roy, Shilpi; Jassal, K; Ganesh, T; Mohanti, BK [Fortis Memorial Research Institute, Gurgaon (India)
2014-06-01T23:59:59.000Z
Purpose: Spatially separated fields are required for craniospinal irradiation due to field size limitation in linear accelerator. Field junction shits are conventionally done to avoid hot or cold spots. Our study was aimed to demonstrate the feasibility of junction free irradiation plan of craniospinal irradiation (CSI) for Meduloblastoma cases treated in linear accelerator using Volumetric modulated arc therapy (VMAT) technique. Methods: VMAT was planned using multiple isocenters in Monaco V 3.3.0 and delivered in Elekta Synergy linear accelerator. A full arc brain and 40° posterior arc spine fields were planned using two isocentre for short (<1.3 meter height ) and 3 isocentres for taller patients. Unrestricted jaw movement was used in superior-inferior direction. Prescribed dose to PTV was achieved by partial contribution from adjacent beams. A very low dose gradient was generated to taper the isodoses over a long length (>10 cm) at the conventional field junction. Results: In this primary study five patients were planned and three patients were delivered using this novel technique. As the dose contribution from the adjacent beams were varied (gradient) to create a complete dose distribution, therefore there is no specific junction exists in the plan. The junction were extended from 10–14 cm depending on treatment plan. Dose gradient were 9.6±2.3% per cm for brain and 7.9±1.7 % per cm for spine field respectively. Dose delivery error due to positional inaccuracy was calculated for brain and spine field for ±1mm, ±2mm, ±3mm and ±5 mm were 1%–0.8%, 2%–1.6%, 2.8%–2.4% and 4.3%–4% respectively. Conclusion: Dose tapering in junction free CSI do not require a junction shift. Therefore daily imaging for all the field is also not essential. Due to inverse planning dose to organ at risk like thyroid kidney, heart and testis can be reduced significantly. VMAT gives a quicker delivery than Step and shoot or dynamic IMRT.
BenAbdallah, Abdallah [Institut superieur d'informatique et multimedia de Sfax BP 242-3021 (Tunisia); Hammami, Mohamed Ali [Faculty of Sciences of Sfax, BP 802-3018 Sfax (Tunisia); Kallel, Jalel [Institut preparatoire aux etudes d'ingenieurs de Sfax BP 1172-3018 (Tunisia)
2009-03-05T23:59:59.000Z
In this paper we present some sufficient conditions for the robust stability and stabilization of time invariant uncertain piecewise linear system using homogenous piecewise polynomial Lyapunov function. The proposed conditions are given in terms of linear matrix inequalities which can be numerically solved. An application of the obtained result is given. It consists in resolving the stabilization of piecewise uncertain linear control systems by using a state piecewise linear feedback.
Domain walls and vortices in linearly coupled systems
Dror, Nir; Zeng, Jianhua
2011-01-01T23:59:59.000Z
We investigate 1D and 2D radial domain-wall (DW) states in the system of two nonlinear-Schr\\"{o}dinger/Gross-Pitaevskii equations, which are coupled by the linear mixing and by the nonlinear XPM (cross-phase-modulation). The system has straightforward applications to two-component Bose-Einstein condensates, and to the bimodal light propagation in nonlinear optics. In the former case, the two components represent different hyperfine atomic states, while in the latter setting they correspond to orthogonal polarizations of light. Conditions guaranteeing the stability of flat continuous wave (CW) asymmetric bimodal states are established, followed by the study of families of the corresponding DW patterns. Approximate analytical solutions for the DWs are found near the point of the symmetry-breaking bifurcation of the CW states. An exact DW solution is produced for ratio 3:1 of the XPM and SPM coefficients. The DWs between flat asymmetric states, which are mirror images to each other, are completely stable, and al...
Li, H.
2008-01-01T23:59:59.000Z
Yu, S. S. , "Relativistic Klystron Two-Beam Accelerator,"Consideration of Relativistic Klystron Two-Beam AcceleratorStudy of the Relativistic Klystron Two-Beam Accelerator
Advanced Klystrons for High Efficiency Accelerator Systems - Final Report
Read, Michael; Ives, Robert Lawrence
2014-03-26T23:59:59.000Z
This program explored tailoring of RF pulses used to drive accelerator cavities. Simulations indicated that properly shaping the pulse risetime to match accelerator cavity characteristics reduced reflected power and increased total efficiency. Tailoring the pulse requires a high power, gridded, klystron to shape the risetime while also controlling the beam current. The Phase I program generated a preliminary design of a gridded electron gun for a klystron producing 5-10 MW of RF power. This required design of a segmented cathode using Controlled Porosity Reservoir cathodes to limit power deposition on the grid. The program was successful in computationally designing a gun producing a high quality electron beam with grid control. Additional analysis of pulse tailoring indicated that technique would only be useful for cavity drive pulses that were less than approximately 2-3 times the risetime. Otherwise, the efficiency gained during the risetime of the pulse became insignificant when considering the efficiency over the entire pulse. Consequently, it was determined that a Phase II program would not provide sufficient return to justify the cost. Never the less, other applications for a high power gridded gun are currently being pursued. This klystron, for example, would facilitate development inverse Comptom x-ray sources by providing a high repetition rate (10 -100 kHz) RF source.
Interconnected Automata and Linear Systems: A Theoretical Framework in Discrete-Time
Sontag, Eduardo
the power of hybrid systems may be exhibited in this context: · As models of systems to be controlled: one ranging from aerospace to automotive control. Linear systems provide highly accurate models of many Systems Linear control theory is well-developed and highly sophisticated, and is widely applied in areas
Beam dynamics study of a 30?MeV electron linear accelerator to drive a neutron source
Kumar, Sandeep; Yang, Haeryong; Kang, Heung-Sik, E-mail: hskang@postech.ac.kr [Pohang Accelerator Laboratory, San31, Hyoja-dong, Pohang, Gyeongbuk 790-784 (Korea, Republic of)
2014-02-14T23:59:59.000Z
An experimental neutron facility based on 32?MeV/18.47?kW electron linac has been studied by means of PARMELA simulation code. Beam dynamics study for a traveling wave constant gradient electron accelerator is carried out to reach the preferential operation parameters (E?=?30?MeV, P?=?18?kW, dE/E?accelerating columns. A disk-loaded, on-axis-coupled, 2?/3-mode type accelerating rf cavity is considered for this linac. After numerous optimizations of linac parameters, 32?MeV beam energy is obtained at the end of the linac. As high electron energy is required to produce acceptable neutron flux. The final neutron flux is estimated to be 5?×?10{sup 11}?n/cm{sup 2}/s/mA. Future development will be the real design of a 30?MeV electron linac based on S band traveling wave.
Bontempi, Gianluca
Lazy learning indirect control for discrete-time non-linear systems Gianluca Bontempi, Mauro propose a hybrid architecture for the indirect control of non linear discrete time plants from of the resulting controller in a simplified case. Experimental results in the control of some non linear benchmarks
Hierarchical Design of Piecewise Linear Hybrid Dynamical Systems Using a Control Regulator Approach
Koutsoukos, Xenofon D.
Hierarchical Design of Piecewise Linear Hybrid Dynamical Systems Using a Control Regulator Approach.edu Abstract This paper presents a novel framework for hierarchical control of piecewise linear hybrid between the continuous and the discrete part is defined by piecewise linear maps. Control design is for
Linear Control of Nonlinear Systems The Interplay between Nonlinearity and Feedback
Nikolaou, Michael
1 Linear Control of Nonlinear Systems The Interplay between Nonlinearity and Feedback S. Alper computational methodology that addresses the question of when and what linear control is adequate linear and/or b. the controlled process will be operating closely enough to a steady state for its
On the Stabilisation of Linear Unstable Systems with Control Constraints y
Braslavsky, Julio H.
On the Stabilisation of Linear Unstable Systems with Control Constraints y J. H. Braslavsky and R, and another using any standard linear controller design. A switching strategy, with hysteresis, is suggested so that locally, the linear control behaviour is achieved, but nonlocally, the maximal possible
Amplitude Linearizers for PEP-II 1.2 MW Klystrons and LLRF Systems
Van Winkle, D.; Browne, J.; Fox, J.D.; Mastorides, T.; Rivetta, C.; Teytelman, D.; /SLAC
2006-07-18T23:59:59.000Z
The PEP-II B-factory has aggressive current increases planned for luminosity through 2008. At 2.2A (HER) on 4A (LER) currents, we estimate that longitudinal growth rates will be comparable to the damping rates currently achieved in the existing low level RF and longitudinal feedback systems. Prior to having a good non-linear time domain model [1] it was postulated that klystron small signal gain non-linearity may be contributing to measured longitudinal growth rates being higher than linearly predicted growth rates. Five prototype klystron amplitude modulation linearizers have been developed to explore improved linearity in the LLRF system. The linearizers operate at 476 MHz with 15 dB dynamic range and 1 MHz linear control bandwidth. Results from lab measurements and high current beam tests are presented. Future development plans, conclusions from beam testing and ideas for future use of this linearization technique are presented.
Allen, Matthew S.
Identifying parameters of nonlinear structural dynamic systems using linear time- periodic nonlinearity. 1. Introduction Most dynamical systems behave nonlinearly in the most general scenario. This can point bifurcation [1], in rotor dynamic systems with bearing contact nonlinearities [2], in biomechanics
On the Parameter Estimation of Linear Models of Aggregate Power System Loads
Cañizares, Claudio A.
1 On the Parameter Estimation of Linear Models of Aggregate Power System Loads Valery Knyazkin-- This paper addressed some theoretical and practical issues relevant to the problem of power system load, and the corresponding results are used to validate a commonly used linear model of aggre- gate power system load
Mixtures of Predictive Linear Gaussian Models for Nonlinear Stochastic Dynamical Systems
Baveja, Satinder Singh
Mixtures of Predictive Linear Gaussian Models for Nonlinear Stochastic Dynamical Systems David dynamical systems. The primary contribution of this work is to extend the PLG to nonlinear, stochastic- proves upon traditional linear dynamical system mod- els by using a predictive representation of state
Stochastic study of a non-linear self-excited system with E. Sarrouya,
Paris-Sud XI, Université de
changes) using MEgPC for a system with dry friction when one parameter (the friction coefficient) variesStochastic study of a non-linear self-excited system with friction E. Sarrouya, , O. Dessombza , J on the Polynomial Chaos to carry out the stochastic study of a self-excited non-linear system with friction which
A linear theory for control of non-linear stochastic systems
H. J. Kappen
2005-10-05T23:59:59.000Z
We address the role of noise and the issue of efficient computation in stochastic optimal control problems. We consider a class of non-linear control problems that can be formulated as a path integral and where the noise plays the role of temperature. The path integral displays symmetry breaking and there exist a critical noise value that separates regimes where optimal control yields qualitatively different solutions. The path integral can be computed efficiently by Monte Carlo integration or by Laplace approximation, and can therefore be used to solve high dimensional stochastic control problems.
HIGH-POWER PRECISION CURRENT SUPPLY IST2-1000M FOR ELEMENTS OF MAGNETIC SYSTEMS OF ACCELERATORS AND
Kozak, Victor R.
HIGH-POWER PRECISION CURRENT SUPPLY IST2-1000M FOR ELEMENTS OF MAGNETIC SYSTEMS OF ACCELERATORS. These supplies are intended to power magnetic systems of accelerators, requiring high stability and low ripples current at non-inductive load % 0,02 Rate of current raise without disturbing operation of the system
Advanced Accelerator Concepts Workshop
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
FOR LINEAR COLLIDERS Serguei Kalmykov Laser wakefield acceleration by petawatt ultra-short laser pulses David Yu NEW DEVELOPMENTS ON PBG RF CAVITIES Mitsuru Uesaka...
Design of penalty functions for optimal control of linear dynamical systems under state and input of solving a constrained optimal control for a general single-input single output linear time varying system dimensional (functional optimization) case. The main novelty is that both the bounds on the control variable
A LYAPUNOV FUNCTION FOR SYSTEMS WHOSE LINEAR PART IS ALMOST CLASSICALLY DAMPED
Cox, Steven J.
A LYAPUNOV FUNCTION FOR SYSTEMS WHOSE LINEAR PART IS ALMOST CLASSICALLY DAMPED Steven J. Coxy) Spain Abstract: We show that one may construct a Lyapunov function for any classically damped linear system. The explicit nature of the construction permits us to show that it remains a Lyapunov function
Wehenkel, Louis
Lecture 7 The Kalman filter · Linear system driven by stochastic process · Statistical steady-state · Linear Gauss-Markov model · Kalman filter · Steady-state Kalman filter 71 #12;Linear system driven.e., the means propagate by the same linear dynamical system The Kalman filter 72 #12;now let's consider
Wang, Yuan
the controllability of switched linear sys- tems. The structure of accessibility Lie algebra is revealed. Some accessi or normal) controllability of a large class of switched linear systems are obtained. Index Terms--Accessibility, controllability, Lie algebra, switched linear system. I. INTRODUCTION Consider a switched linear system _x(t) = A
Sontag, Eduardo
optimal control (CFTOC) problem for the class of discrete-time linear hybrid systems. For a linear control (CITOC) problem with linear performance index for constrained PWA systems was recently presentedStability Analysis of Hybrid Systems with a Linear Performance Index Frank J. Christophersen, Mato
Asynchronous data change notification between database server and accelerator controls system
Fu, W.; Morris, J.; Nemesure, S.
2011-10-10T23:59:59.000Z
Database data change notification (DCN) is a commonly used feature. Not all database management systems (DBMS) provide an explicit DCN mechanism. Even for those DBMS's which support DCN (such as Oracle and MS SQL server), some server side and/or client side programming may be required to make the DCN system work. This makes the setup of DCN between database server and interested clients tedious and time consuming. In accelerator control systems, there are many well established software client/server architectures (such as CDEV, EPICS, and ADO) that can be used to implement data reflection servers that transfer data asynchronously to any client using the standard SET/GET API. This paper describes a method for using such a data reflection server to set up asynchronous DCN (ADCN) between a DBMS and clients. This method works well for all DBMS systems which provide database trigger functionality. Asynchronous data change notification (ADCN) between database server and clients can be realized by combining the use of a database trigger mechanism, which is supported by major DBMS systems, with server processes that use client/server software architectures that are familiar in the accelerator controls community (such as EPICS, CDEV or ADO). This approach makes the ADCN system easy to set up and integrate into an accelerator controls system. Several ADCN systems have been set up and used in the RHIC-AGS controls system.
Collider-Accelerator Department/SNSRing Systems BROOKHAVENNATIONALLABORATORY
shall be installed by Brookhaven National Laboratory (BNL) as part of a large magnet power system ANSI/IEEE C57 Distribution, Power and Regulating Transformers NFPA70 National ElectricCode IEEE 5ScienceAssociates Upton, New York 11973 SPEC. SNS-OO9 December 14, 1999 SDecification for Iuiection Bumo Power Suoolies "T
Xiaofeng Wu; Guanrong Chen; Jianping Cai
2008-07-14T23:59:59.000Z
This paper provides a unified method for analyzing chaos synchronization of the generalized Lorenz systems. The considered synchronization scheme consists of identical master and slave generalized Lorenz systems coupled by linear state error variables. A sufficient synchronization criterion for a general linear state error feedback controller is rigorously proven by means of linearization and Lyapunov's direct methods. When a simple linear controller is used in the scheme, some easily implemented algebraic synchronization conditions are derived based on the upper and lower bounds of the master chaotic system. These criteria are further optimized to improve their sharpness. The optimized criteria are then applied to four typical generalized Lorenz systems, i.e. the classical Lorenz system, the Chen system, the Lv system and a unified chaotic system, obtaining precise corresponding synchronization conditions. The advantages of the new criteria are revealed by analytically and numerically comparing their sharpness with that of the known criteria existing in the literature.
Perinic, G; Alonso-Canella, I; Balle, C; Barth, K; Bel, J F; Benda, V; Bremer, J; Brodzinski, K; Casas-Cubillos, J; Cuccuru, G; Cugnet, M; Delikaris, D; Delruelle, N; Dufay-Chanat, L; Fabre, C; Ferlin, G; Fluder, C; Gavard, E; Girardot, R; Haug, F; Herblin, L; Junker, S; Klabi , T; Knoops, S; Lamboy, J P; Legrand, D; Metselaar, J; Park, A; Perin, A; Pezzetti, M; Penacoba-Fernandez, G; Pirotte, O; Rogez, E; Suraci, A; Stewart, L; Tavian, L J; Tovar-Gonzalez, A; Van Weelderen, R; Vauthier, N; Vullierme, B; Wagner, U
2012-01-01T23:59:59.000Z
The Large Hadron Collider (LHC) cryogenic system comprises eight independent refrigeration and distribution systems that supply the eight 3.3 km long accelerator sectors with cryogenic refrigeration power as well as four refrigeration systems for the needs of the detectors ATLAS and CMS. In order to ensure the highest possible reliability of the installations, it is important to apply a reliability centred approach for the maintenance. Even though large scale cryogenic refrigeration exists since the mid 20th century, very little third party reliability data is available today. CERN has started to collect data with its computer aided maintenance management system (CAMMS) in 2009, when the accelerator has gone into normal operation. This paper presents the reliability observations from the operation and the maintenance side, as well as statistical data collected by the means of the CAMMS system.
Baillie, Devin [Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Aubin, J. St. [Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Fallone, B. G. [Department of Physics, University of Alberta, 11322-89 Avenue, Edmonton, Alberta T6G 2G7 (Canada); Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Steciw, S. [Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada)
2013-04-15T23:59:59.000Z
Purpose: To use a finite-element method (FEM) model to study the feasibility of producing a short s-band (2.9985 GHz) waveguide capable of producing x-rays energies up to 10 MV, for applications in a linac-MR, as well as conventional radiotherapy. Methods: An existing waveguide FEM model developed by the authors' group is used to simulate replacing the magnetron power source with a klystron. Peak fields within the waveguide are compared with a published experimental threshold for electric breakdown. The RF fields in the first accelerating cavity are scaled, approximating the effect of modifications to the first coupling cavity. Electron trajectories are calculated within the RF fields, and the energy spectrum, beam current, and focal spot of the electron beam are analyzed. One electron spectrum is selected for Monte Carlo simulations and the resulting PDD compared to measurement. Results: When the first cavity fields are scaled by a factor of 0.475, the peak magnitude of the electric fields within the waveguide are calculated to be 223.1 MV/m, 29% lower than the published threshold for breakdown at this operating frequency. Maximum electron energy increased from 6.2 to 10.4 MeV, and beam current increased from 134 to 170 mA. The focal spot FWHM is decreased slightly from 0.07 to 0.05 mm, and the width of the energy spectrum increased slightly from 0.44 to 0.70 MeV. Monte Carlo results show d{sub max} is at 2.15 cm for a 10 Multiplication-Sign 10 cm{sup 2} field, compared with 2.3 cm for a Varian 10 MV linac, while the penumbral widths are 4.8 and 5.6 mm, respectively. Conclusions: The authors' simulation results show that a short, high-energy, s-band accelerator is feasible and electric breakdown is not expected to interfere with operation at these field strengths. With minor modifications to the first coupling cavity, all electron beam parameters are improved.
Chattopadhyay, S.; Byrns, R.; Donahue, R.; Edighoffer, J.; Gough, R.; Hoyer, E.; Kim, K.J.; Leemans, W.; Staples, J.; Taylor, B.; Xie, M.
1992-08-01T23:59:59.000Z
An accelerator complex has recently been designed at LBL as part of an Infrared Free Electron Laser facility in support of a proposed Chemical Dynamics Research Laboratory. We will outline the choice of parameters and design philosophy, which are strongly driven by the demand of reliable and spectrally stable operation of the FEL for very special scientific experiments. The design is based on a 500 MHz recirculating superconducting electron linac with highest energy reach of about 60 MeV. The accelerator is injected with beams prepared by a specially designed gun-buncher system and incorporates a near-isochronous and achromatic recirculation line tunable over a wide range of beam energies. The stability issues considered to arrive at the specific design will be outlined.
Accelerating Acceptance of Fuel Cell Backup Power Systems - Final Report
Petrecky, James; Ashley, Christopher
2014-07-21T23:59:59.000Z
Since 2001, Plug Power has installed more than 800 stationary fuel cell systems worldwide. Plug Power’s prime power systems have produced approximately 6.5 million kilowatt hours of electricity and have accumulated more than 2.5 million operating hours. Intermittent, or backup, power products have been deployed with telecommunications carriers and government and utility customers in North and South America, Europe, the United Kingdom, Japan and South Africa. Some of the largest material handling operations in North America are currently using the company’s motive power units in fuel cell-powered forklifts for their warehouses, distribution centers and manufacturing facilities. The low-temperature GenSys fuel cell system provides remote, off-grid and primary power where grid power is unreliable or nonexistent. Built reliable and designed rugged, low- temperature GenSys delivers continuous or backup power through even the most extreme conditions. Coupled with high-efficiency ratings, low-temperature GenSys reduces operating costs making it an economical solution for prime power requirements. Currently, field trials at telecommunication and industrial sites across the globe are proving the advantages of fuel cells—lower maintenance, fuel costs and emissions, as well as longer life—compared with traditional internal combustion engines.
Exposure of Polymeric Glazing Materials Using NREL's Ultra-Accelerated Weathering System (UAWS)
Bingham, C.; Jorgensen, G.; Wylie, A.
2010-01-01T23:59:59.000Z
NREL's Ultra-Accelerated Weathering System (UAWS) selectively reflects and concentrates natural sunlight ultraviolet irradiance below 475 nm onto exposed samples to provide accelerated weathering of materials while keeping samples within realistic temperature limits. This paper will explain the design and implementation of the UAWS which allow it to simulate the effect of years of weathering in weeks of exposure. Exposure chamber design and instrumentation will be discussed for both a prototype UAWS used to test glazing samples as well as a commercial version of UAWS. Candidate polymeric glazing materials have been subjected to accelerated exposure testing at a light intensity level of up to 50 UV suns for an equivalent outdoor exposure in Miami, FL exceeding 15 years. Samples include an impact modified acrylic, fiberglass, and polycarbonate having several thin UV-screening coatings. Concurrent exposure is carried out for identical sample sets at two different temperatures to allow thermal effects to be quantified along with resistance to UV.
Norem, J.; Brandeberry, F.; Rauchas, A.
1983-08-01T23:59:59.000Z
The Rapid Cycling Synchrotron (RCS) of the Intense Pulsed Neutron Source (IPNS) operating at Argonne National Laboratory is presently producing intensities of 2-2.5 x 10/sup 12/ protons per pulse (ppp) with the addition of a new ion source. This intensity is close to the space charge limit of the machine, estimated at about 3 x 10/sup 12/ ppp, depending somewhat on the available aperture. With the present good performance in mind, accelerator improvements are being directed at increasing beam intensities for neutron science, lowering acceleration losses to minimize activation, and gaining better control of the beam so that losses can be made to occur when and where they can be most easily controlled. On the basis of preliminary measurements, the authors are now proposing a third cavity for the RF system which would provide control of the longitudinal bunch shape during the cycle which would permit raising the effective space charge limit of the accelerator and reducing losses.
Selection of Output Function in Nonlinear Feedback Linearizing Excitation Control for Power Systems
Pota, Himanshu Roy
Selection of Output Function in Nonlinear Feedback Linearizing Excitation Control for Power Systems for power systems. Depending on the relative degree of the system which depends on the output function Power systems are large, complex, and highly nonlinear interconnected dynamic systems. The power demand
Centrifugal accelerator, system and method for removing unwanted layers from a surface
Foster, Christopher A. (Clinton, TN); Fisher, Paul W. (Heiskell, TN)
1995-01-01T23:59:59.000Z
A cryoblasting process having a centrifugal accelerator for accelerating frozen pellets of argon or carbon dioxide toward a target area utilizes an accelerator throw wheel designed to induce, during operation, the creation of a low-friction gas bearing within internal passages of the wheel which would otherwise retard acceleration of the pellets as they move through the passages. An associated system and method for removing paint from a surface with cryoblasting techniques involves the treating, such as a preheating, of the painted surface to soften the paint prior to the impacting of frozen pellets thereagainst to increase the rate of paint removal. A system and method for producing large quantities of frozen pellets from a liquid material, such as liquid argon or carbon dioxide, for use in a cryoblasting process utilizes a chamber into which the liquid material is introduced in the form of a jet which disintegrates into droplets. A non-condensible gas, such as inert helium or air, is injected into the chamber at a controlled rate so that the droplets freeze into bodies of relatively high density.
of Linear and Nonlinear Optimisation in the Electricity Sector Miguel F. Anjos Professor and Canada Research Chair Interim Director, Trottier Energy Institute Various parts are joint work with T. Barbier (Poly Mtl of electricity markets. Most models incorporate the transmission system by using linear DC approximations
LASER-PLASMA-ACCELERATOR-BASED GAMMA GAMMA COLLIDERS
Schroeder, C. B.
2010-01-01T23:59:59.000Z
LASER-PLASMA-ACCELERATOR-BASED ?? COLLIDERS ? C. B.linear col- lider based on laser-plasma-accelerators arediscussed, and a laser-plasma-accelerator-based gamma-
Optimal Controllers for Hybrid Systems: Stability and Piecewise Linear Explicit Form
Sontag, Eduardo
of the heat exchange system [16] shows the potential of the method. Keywords: Hybrid systems, model predictiveOptimal Controllers for Hybrid Systems: Stability and Piecewise Linear Explicit Form A. Bemporad for hybrid sys- tems and investigate conditions for closed-loop stabil- ity. Hybrid systems are modeled
Performance Limitations of Linear Systems over Additive White Noise Channels
Li, Yiqian
2011-01-01T23:59:59.000Z
Control over additive white noise channels . . . . . . . 1.3Additive white noise channel . . . . . . . . . . . . . . Angaussian systems over additive gaussian wireles fading
ON HIGHER ORDER EMBEDDINGS OF FANO THREEFOLDS BY THE ANTICANONICAL LINEAR SYSTEM
Sommese, Andrew J.
ON HIGHER ORDER EMBEDDINGS OF FANO THREEFOLDS BY THE ANTICANONICAL LINEAR SYSTEM MAURO C. BELTRAMETTI, SANDRA DI ROCCO, AND ANDREW J. SOMMESE Abstract to a number of natural notions of higher order embeddings of* * projective manifolds. This is of importance
13th International Conference on Magnetically Levitated Systems and Linear Drives
Not Available
1993-09-01T23:59:59.000Z
This report contains short papers on research being conducted throughout the world on magnetically levitated systems, mainly consisting of trains, and magnetic linear drives. These papers have been index separately elsewhere on the data base.
Linear and Nonlinear Optics in a System of Massless Dirac Fermions
Yao, Xianghan
2014-08-10T23:59:59.000Z
Graphene electrons possess linear energy dispersion relation, and thus behave as two-dimensional (2D) Dirac fermions. Consequently, compared with the conventional 2D electron gas systems (2DEG) found in MOSFETs and quantum ...
Shih-Yuin Lin; B. L. Hu
2008-07-24T23:59:59.000Z
We study an exactly solvable model where an uniformly accelerated detector is linearly coupled to a massless scalar field initially in the Minkowski vacuum. Using the exact correlation functions we show that as soon as the coupling is switched on one can see information flowing from the detector to the field and propagating with the radiation into null infinity. By expressing the reduced density matrix of the detector in terms of the two-point functions, we calculate the purity function in the detector and study the evolution of quantum entanglement between the detector and the field. Only in the ultraweak coupling regime could some degree of recoherence in the detector appear at late times, but never in full restoration. We explicitly show that under the most general conditions the detector never recovers its quantum coherence and the entanglement between the detector and the field remains large at late times. To the extent this model can be used as an analog to the system of a black hole interacting with a quantum field, our result seems to suggest in the prevalent non-Markovian regime, assuming unitarity for the combined system, that black hole information is not lost but transferred to the quantum field degrees of freedom. Our combined system will evolve into a highly entangled state between a remnant of large area (in Bekenstein's black hole atom analog) without any information of its initial state, and the quantum field, now imbued with complex information content not-so-easily retrievable by a local observer.
Qiang Zhao; Zhiyong He; Lei Yang; Xueying Zhang; Wenjuan Cui; Zhiqiang Chen; Hushan Xu
2015-08-09T23:59:59.000Z
In this paper, we study the monitoring method of neutron flux for the spallation target used in an accelerator driven sub-critical (ADS) system, where the spallation target located vertically at the centre of a sub-critical core is bombarded vertically by the high-energy protons from an accelerator. First, by considering the characteristics in the spatial variation of neutron flux from the spallation target, we propose the following multi-point measurement technique, i.e. the spallation neutron flux should be measured at multiple vertical locations. To explain why the flux should be measured at multiple locations, we have studied the neutron production from tungsten target bombarded by a 250 MeV-proton beam with the Geant4-based Monte Carlo simulations. The simulation results have indicated that the neutron flux at the central location is up to three orders of magnitude higher than the flux at the lower locations. Secondly, we have developed an effective technique in order to measure the spallation neutron flux with the fission chamber (FC). The effective technique consists in establishing the relation between the fission rate measured by FC and the spallation neutron flux. Since this relation is linear for FC, a constant calibration factor is used to derive the neutron flux from the measured fission rate. This calibration factor can be extracted from the energy spectra of spallation neutrons. Finally, we have evaluated the proposed calibration method for FC in the environment of ADS system. The results indicate that the proposed method functions very well when the neutron flux is below 10^{13} neutron/cm^2/second.
Diffusive Acceleration of Ions at Interplanetary Shocks
Matthew G. Baring; Errol J. Summerlin
2005-06-08T23:59:59.000Z
Heliospheric shocks are excellent systems for testing theories of particle acceleration in their environs. These generally fall into two classes: (1) interplanetary shocks that are linear in their ion acceleration characteristics, with the non-thermal ions serving as test particles, and (2) non-linear systems such as the Earth's bow shock and the solar wind termination shock, where the accelerated ions strongly influence the magnetohydrodynamic structure of the shock. This paper explores the modelling of diffusive acceleration at a particular interplanetary shock, with an emphasis on explaining in situ measurements of ion distribution functions. The observational data for this event was acquired on day 292 of 1991 by the Ulysses mission. The modeling is performed using a well-known kinetic Monte Carlo simulation, which has yielded good agreement with observations at several heliospheric shocks, as have other theoretical techniques, namely hybrid plasma simulations, and numerical solution of the diffusion-convection equation. In this theory/data comparison, it is demonstrated that diffusive acceleration theory can, to first order, successfully account for both the proton distribution data near the shock, and the observation of energetic protons farther upstream of this interplanetary shock than lower energy pick-up protons, using a single turbulence parameter. The principal conclusion is that diffusive acceleration of inflowing upstream ions can model this pick-up ion-rich event without the invoking any seed pre-acceleration mechanism, though this investigation does not rule out the action of such pre-acceleration.
Sontag, Eduardo
Infinite Time Optimal Control of Hybrid Systems with a Linear Performance Index Mato BaotiÂ´c, Frank the constrained infinite time optimal control problem for the class of discrete time linear hybrid systems. When time, optimal control, discrete time, linear hybrid systems, dynamic program- ming, multi
Johansson, Karl Henrik
Controllability of a class of networked passive linear systems Bart Besselink, Henrik Sandberg- works of diffusively coupled linear systems are considered through the controllability Gramian. For a class of passive linear systems, it is shown that the controllability Gramian can be decomposed into two
Mamalui-Hunter, M; Wu, J; Li, Z; Su, Z [University of Florida/Radiation Oncology, Jacksonville, FL (United States)
2014-06-01T23:59:59.000Z
Purpose: Following the ‘end-to-end testing’ paradigm of Dynamic Target Tracking option in our Image-Guided dedicated SBRT VeroTM linac, we verify the capability of the system to deliver planned dose to moving targets in the heterogeneous thorax phantom (CIRSTM). The system includes gimbaled C-band linac head, robotic 6 degree of freedom couch and a tumor tracking method based on predictive modeling of target position using fluoroscopically tracked implanted markers and optically tracked infrared reflecting external markers. Methods: 4DCT scan of the motion phantom with the VisicoilTM implanted marker in the close vicinity of the target was acquired, the ‘exhale’=most prevalent phase was used for planning (iPlan by BrainLabTM). Typical 3D conformal SBRT treatment plans aimed to deliver 6-8Gy/fx to two types of targets: a)solid water-equivalent target 3cm in diameter; b)single VisicoilTM marker inserted within lung equivalent material. The planning GTV/CTV-to-PTV margins were 2mm, the block margins were 3 mm. The dose calculated by MonteCarlo algorithm with 1% variance using option Dose-to-water was compared to the ion chamber (CC01 by IBA Dosimetry) measurements in case (a) and GafchromicTM EBT3 film measurements in case (b). During delivery, the target 6 motion patterns available as a standard on CIRSTM motion phantom were investigated: in case (a), the target was moving along the designated sine or cosine4 3D trajectory; in case (b), the inserted marker was moving sinusoidally in 1D. Results: The ion chamber measurements have shown the agreement with the planned dose within 1% under all the studied motion conditions. The film measurements show 98.1% agreement with the planar calculated dose (gamma criteria: 3%/3mm). Conclusion: We successfully verified the capability of the SBRT VeroTM linac to perform real-time tumor tracking and accurate dose delivery to the target, based on predictive modeling of the correlation between implanted marker motion and external surrogate of breathing motion.
Nonlinear Excitation Control of Power Systems with Dynamic Loads via Feedback Linearization
Pota, Himanshu Roy
Nonlinear Excitation Control of Power Systems with Dynamic Loads via Feedback Linearization M. A.Pota)@adfa.edu.au Abstract--This paper presents a nonlinear control design method for interconnected power systems points. I. INTRODUCTION Control of modern electric power systems becomes more and more challenging
Approximate Hierarchies of Linear Control Systems Antoine Girard and George J. Pappas
Pappas, George J.
Approximate Hierarchies of Linear Control Systems Antoine Girard and George J. Pappas Abstract introduced. The proposed hierarchical control architecture consists of a precise model (the concrete system) of the plant to be controlled and of a rough model (the abstract system) of the plant that is used for control
A 20-SUN HYBRID PV-THERMAL LINEAR MICRO-CONCENTRATOR SYSTEM FOR URBAN ROOFTOP APPLICATIONS
, ACT, Australia P. Le Livre 2 , M. Greaves 2 , A. Tanner 2 2 Chromasun Inc, San Jose, CA, United States of America ABSTRACT A unique, linear, low-concentration, hybrid `micro- concentrator' (MCT) system concept, system output of 500 Wpe and 2 kWpt is expected, for a combined system efficiency of up to 75%. The MCT
Antsaklis, Panos
A Linear Programming Approach to Time Optimal Control of Integrator Switched Systems with State, USA Abstract-- In this paper, time optimal control problems of a class of integrator switched systems Recently, optimal control problems of switched and hybrid systems have attracted many researchers from
Optimal Control of Discrete-Time Linear Systems with Network-Induced Varying Delay
importance in modern systems applications. However, most traditional digital control and algorithmsOptimal Control of Discrete-Time Linear Systems with Network-Induced Varying Delay Hiroyuki Hirano for networked control systems, that have network induced time delay in the communication networks. In our
Distributed state estimation and model predictive control of linear interconnected system
Boyer, Edmond
requirements, modern control systems are becoming more and more complex. For these processes, different controlDistributed state estimation and model predictive control of linear interconnected system: In this paper, a distributed and networked control system architecture based on independent Model Predictive
Stabilization of Linear Dynamical Systems with Scalar Quantizers under Communication Constraints
Reissig, Gunther
Stabilization of Linear Dynamical Systems with Scalar Quantizers under Communication Constraints for stabilizing the system at reduced data rates. I. INTRODUCTION Historically, communication and control have been an increasing demand on networks consisting of control and communication systems which are subject
Tian, Zhen; Li, Yongbao; Shi, Feng; Jiang, Steve B; Jia, Xun
2015-01-01T23:59:59.000Z
We recently built an analytical source model for GPU-based MC dose engine. In this paper, we present a sampling strategy to efficiently utilize this source model in GPU-based dose calculation. Our source model was based on a concept of phase-space-ring (PSR). This ring structure makes it effective to account for beam rotational symmetry, but not suitable for dose calculations due to rectangular jaw settings. Hence, we first convert PSR source model to its phase-space let (PSL) representation. Then in dose calculation, different types of sub-sources were separately sampled. Source sampling and particle transport were iterated. So that the particles being sampled and transported simultaneously are of same type and close in energy to alleviate GPU thread divergence. We also present an automatic commissioning approach to adjust the model for a good representation of a clinical linear accelerator . Weighting factors were introduced to adjust relative weights of PSRs, determined by solving a quadratic minimization ...
Caporaso, George J. (Livermore, CA); Sampayan, Stephen E. (Manteca, CA); Kirbie, Hugh C. (Los Alamos, NM)
2007-02-06T23:59:59.000Z
A compact linear accelerator having at least one strip-shaped Blumlein module which guides a propagating wavefront between first and second ends and controls the output pulse at the second end. Each Blumlein module has first, second, and third planar conductor strips, with a first dielectric strip between the first and second conductor strips, and a second dielectric strip between the second and third conductor strips. Additionally, the compact linear accelerator includes a high voltage power supply connected to charge the second conductor strip to a high potential, and a switch for switching the high potential in the second conductor strip to at least one of the first and third conductor strips so as to initiate a propagating reverse polarity wavefront(s) in the corresponding dielectric strip(s).
Linear Sum Assignment Algorithms for Distributed Multi-robot Systems
Liu, Lantao
2013-04-30T23:59:59.000Z
Multi-robot task assignment (allocation) involves assigning robots to tasks in order to optimize the entire team’s performances. Until now, one of the most useful non-domain-specific ways to coordinate multi-robot systems is through task allocation...
An efficient algorithm for damper optimization for linear vibrating systems
Truhar, Ninoslav
of the bridge with the wind induced oscillatory forces. For the majority of engineering applications, resonance, used in [14], is given by requirement of the minimization of the total energy of the system, that is 0 E(t) dt = min (1.4) The advantage of this criterion are: (i) its obvious closeness to the total en
Solving systems of linear equations using a grid structural outlook
Awwad, A.M.; Al-Ayyoub, A.; Ould-Khaoua, M.
Awwad,A.M. Al-Ayyoub,A. Ould-Khaoua,M. Day,K. Proceedings 13th IASTED International Conference Parallel and Distributed Computing and Systems (PDCS 2001), Anaheim, California, August 21-24, 2001. pp 365-369 CSREA Press
SEQUENTIAL MONTE CARLO TECHNIQUES FOR THE SOLUTION OF LINEAR SYSTEMS
Li, Yaohang
the solutions to mathematical problems (whether they have a probabilistic background or not), is very ancient reactors, radiation shielding, nuclear fission and fusion bombs; studies of percolation and diffusion in optimization, operations research, and systems analysis. The underlying mathematical concept is simple. We
Tallerico, P.J.; Lynch, M.T.
1993-11-01T23:59:59.000Z
RF driven proton accelerators for the transmutation of nuclear waste (ATW) or for the production of tritium (APT) require unprecedented amounts of CW RF power at UHF frequencies. For both systems, the baseline design is for 246 MW at 700 MHz and 8,5 MW at 350 MHz. The main technical challenges are how to design and build such a large system so that it has excellent reliability, high efficiency, and reasonable capital cost. The issues associated with the selection of the RF amplifier and the sizes of the power supplies are emphasized in this paper.
Amesos2 and Belos: Direct and Iterative Solvers for Large Sparse Linear Systems
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Bavier, Eric; Hoemmen, Mark; Rajamanickam, Sivasankaran; Thornquist, Heidi
2012-01-01T23:59:59.000Z
Solvers for large sparse linear systems come in two categories: direct and iterative. Amesos2, a package in the Trilinos software project, provides direct methods, and Belos, another Trilinos package, provides iterative methods. Amesos2 offers a common interface to many different sparse matrix factorization codes, and can handle any implementation of sparse matrices and vectors, via an easy-to-extend C++ traits interface. It can also factor matrices whose entries have arbitrary “Scalar” type, enabling extended-precision and mixed-precision algorithms. Belos includes many different iterative methods for solving large sparse linear systems and least-squares problems. Unlike competing iterative solver libraries, Belos completely decouples themore »algorithms from the implementations of the underlying linear algebra objects. This lets Belos exploit the latest hardware without changes to the code. Belos favors algorithms that solve higher-level problems, such as multiple simultaneous linear systems and sequences of related linear systems, faster than standard algorithms. The package also supports extended-precision and mixed-precision algorithms. Together, Amesos2 and Belos form a complete suite of sparse linear solvers.« less
Linear systems solvers - recent developments and implications for lattice computations
Andreas Frommer
1996-08-14T23:59:59.000Z
We review the numerical analysis' understanding of Krylov subspace methods for solving (non-hermitian) systems of equations and discuss its implications for lattice gauge theory computations using the example of the Wilson fermion matrix. Our thesis is that mature methods like QMR, BiCGStab or restarted GMRES are close to optimal for the Wilson fermion matrix. Consequently, preconditioning appears to be the crucial issue for further improvements.
Pratt, Preston Persley
2003-01-01T23:59:59.000Z
Accelerator transmutation of waste (ATW) is a new concept that would destroy actinides in spent fuel and produce electrical power. This study explores the possibility of modeling the thermo-hydraulics of this system with computational fluid...
Pratt, Preston Persley
2003-01-01T23:59:59.000Z
Accelerator transmutation of waste (ATW) is a new concept that would destroy actinides in spent fuel and produce electrical power. This study explores the possibility of modeling the thermo-hydraulics of this system with computational fluid...
Beam-driven acceleration in ultra-dense plasma media
Shin, Young-Min [Fermi National Accelerator Laboratory, Batavia, IL (United States)
2014-09-12T23:59:59.000Z
Accelerating parameters of beam-driven wakefield acceleration in an extremely dense plasma column has been analyzed with the dynamic framed particle-in-cell plasma simulator, and compared with analytic calculations. In the model, a witness beam undergoes a TeV/m scale alternating potential gradient excited by a micro-bunched drive beam in a 1025 m-3 and 1.6 x 1028 m-3 plasma column. The acceleration gradient, energy gain, and transformer ratio have been extensively studied in quasi-linear, linear-, and blowout-regimes. The simulation analysis indicated that in the beam-driven acceleration system a hollow plasma channel offers 20 % higher acceleration gradient by enlarging the channel radius (r) from 0.2 Ap to 0.6 .Ap in a blowout regime. This paper suggests a feasibility of TeV/m scale acceleration with a hollow crystalline structure (e.g. nanotubes) of high electron plasma density.
Beam-driven acceleration in ultra-dense plasma media
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Shin, Young-Min [Fermi National Accelerator Laboratory, Batavia, IL (United States)
2014-09-15T23:59:59.000Z
Accelerating parameters of beam-driven wakefield acceleration in an extremely dense plasma column has been analyzed with the dynamic framed particle-in-cell plasma simulator, and compared with analytic calculations. In the model, a witness beam undergoes a TeV/m scale alternating potential gradient excited by a micro-bunched drive beam in a 1025 m-3 and 1.6 x 1028 m-3 plasma column. The acceleration gradient, energy gain, and transformer ratio have been extensively studied in quasi-linear, linear-, and blowout-regimes. The simulation analysis indicated that in the beam-driven acceleration system a hollow plasma channel offers 20 % higher acceleration gradient by enlarging the channel radius (r) from 0.2 ?p to 0.6 ?p in a blowout regime. This paper suggests a feasibility of TeV/m scale acceleration with a hollow crystalline structure (e.g. nanotubes) of high electron plasma density.
Beam-driven acceleration in ultra-dense plasma media
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Shin, Young-Min
2014-09-15T23:59:59.000Z
Accelerating parameters of beam-driven wakefield acceleration in an extremely dense plasma column has been analyzed with the dynamic framed particle-in-cell plasma simulator, and compared with analytic calculations. In the model, a witness beam undergoes a TeV/m scale alternating potential gradient excited by a micro-bunched drive beam in a 1025 m-3 and 1.6 x 1028 m-3 plasma column. The acceleration gradient, energy gain, and transformer ratio have been extensively studied in quasi-linear, linear-, and blowout-regimes. The simulation analysis indicated that in the beam-driven acceleration system a hollow plasma channel offers 20 % higher acceleration gradient by enlarging the channel radius (r)more »from 0.2 ?p to 0.6 ?p in a blowout regime. This paper suggests a feasibility of TeV/m scale acceleration with a hollow crystalline structure (e.g. nanotubes) of high electron plasma density.« less
Linear hydraulic drive system for a Stirling engine
Walsh, Michael M. (Schenectady, NY)
1984-02-21T23:59:59.000Z
A hydraulic drive system operating from the periodic pressure wave produced by a Stirling engine along a first axis thereof and effecting transfer of power from the Stirling engine to a load apparatus therefor and wherein the movable, or working member of the load apparatus is reciprocatingly driven along an axis substantially at right angles to the first axis to achieve an arrangement of a Stirling engine and load apparatus assembly which is much shorter and the components of the load apparatus more readily accessible.
Pole placement design for linear multivariable control systems
Keel, Leehyun
1982-01-01T23:59:59.000Z
. 8893 32. 6274 -48. 5512 -108. 257 6. 93611 36. 2073 -43. 4464. -45. 3662 -13. 3483 -60. 2753 27. 2660 -0. 75720 ? ZO. 6834 -Z5. 3096 5. 45564 -3. 32199 14. . 0371 Condition No. of X = 9249. 36803 Closed Loop System Poles -3. 50001-3. 49998jy -3.... 50001+3. 49998j -2. 00005-1. 99998j& -2. 00005+1. 99998j -2 49994-2. 49995js -2 49994+ 2 49995j -4 . 99940-0, 99980j, -4 . 99940+0 . 99980j -4. 50091 -4. 00025 B the new al orithm tt com anion form 0, -1146600 ? 2341990 -2286968 -1288684 -576460...
Alternative to the Well-known Statistical Dynamics of Linear Systems
V. N. Tibabishev
2013-01-22T23:59:59.000Z
The problem of determining the mathematical model of the dynamics of multi-dimensional control systems in the presence of noise under the condition that the correlation functions cannot be found. Known statistical dynamics of linear systems is a more effective alternative. Background information is presented in the form of individual implementations nonergodic stochastic processes. Such a realization is deterministic functions. We introduce the concept of systems of sets of signals for the components on the semiring. For the system of sets of linearly dependent and linearly independent of the measured signals of a certain frequency properties. Frequency method is designed to deal with the noise on the set of deterministic functions. Example is the determination of the dynamic characteristics of the aircraft in accordance with the data obtained in one automatic landing.
Yao, Bin
Integrated Direct/Indirect Adaptive Robust Precision Control of Linear Motor Drive Systems The focus of the paper is on the synthesis of nonlinear adaptive robust controllers for precision linear control of linear motor drive systems but with an improved estimation model, in which accurate parameter
Jameson, Antony
Optimization of linear systems of constrained configuration Reprinted from: INT. J. CONTROL, 1970-developed theory for the optimal regulation of a linear system [1]. The optimal controller incorporates feedbacks, the lateral motion of an aircraft is represented by a linearized equations, the resulting optimal control
Design of coherent quantum observers for linear quantum systems
Shanon L. Vuglar; Hadis Amini
2015-01-27T23:59:59.000Z
Quantum versions of control problems are often more difficult than their classical counterparts because of the additional constraints imposed by quantum dynamics. For example, the quantum LQG and quantum H infinity optimal control problems remain open. To make further progress, new, systematic and tractable methods need to be developed. This paper gives three algorithms for designing coherent observers, i.e., quantum systems that are connected to a quantum plant and their outputs provide information about the internal state of the plant. Importantly, coherent observers avoid measurements of the plant outputs. We compare our coherent observers with a classical (measurement-based) observer by way of an example involving an optical cavity with thermal and vacuum noises as inputs.
Norem, J.; Brandeberry, F.; Rauchas, A.
1983-01-01T23:59:59.000Z
The Rapid Cycling Synchrotron (RCS) of the Intense Pulsed Neutron Source (IPNS) operating at Argonne National Laboratory is presently producing intensities of 2 to 2.5 x 10/sup 12/ protons per pulse (ppp) with the addition of a new ion source. This intensity is close to the space charge limit of the machine, estimated at approx.3 x 10/sup 12/ ppp, depending somewhat on the available aperture. With the present good performance in mind, accelerator improvements are being directed at: (1) increasing beam intensities for neutron science; (2) lowering acceleration losses to minimize activation; and (3) gaining better control of the beam so that losses can be made to occur when and where they can be most easily controlled. On the basis of preliminary measurements, we are now proposing a third cavity for the RF systems which would provide control of the longitudinal bunch shape during the cycle which would permit raising the effective space charge limit of the accelerator and reducing losses.
Back to the Roots From Polynomial System Solving to Linear Algebra
Back to the Roots Â From Polynomial System Solving to Linear Algebra Philippe Dreesen Bart De Moor systems of polynomial equations have been developed in the area of algebraic geometry. A large body in this research area require exact algebraic computations and suffer from numerical issues. We present a method
LINEAR SYSTEMS WITH SIGNOBSERVATIONS \\Lambda EE SCHWARZSCHILD AND EDUARDO D. SONTAG y
Sontag, Eduardo
of symbolic processing. Classical control techniques, especially for linear systems, have proved spec for the resulting models. Successful approaches will eventually allow the interplay of modern control theory into areas such as discreteÂevent systems, supervisory control, and more generally ``intelligent control
Solar receiver heliostat reflector having a linear drive and position information system
Horton, Richard H. (Schenectady, NY)
1980-01-01T23:59:59.000Z
A heliostat for a solar receiver system comprises an improved drive and control system for the heliostat reflector assembly. The heliostat reflector assembly is controllably driven in a predetermined way by a light-weight drive system so as to be angularly adjustable in both elevation and azimuth to track the sun and efficiently continuously reflect the sun's rays to a focal zone, i.e., heat receiver, which forms part of a solar energy utilization system, such as a solar energy fueled electrical power generation system. The improved drive system includes linear stepping motors which comprise low weight, low cost, electronic pulse driven components. One embodiment comprises linear stepping motors controlled by a programmed, electronic microprocessor. Another embodiment comprises a tape driven system controlled by a position control magnetic tape.
Caporaso, G.J.; Sampayan, S.E.; Kirbie, H.C.
1998-10-13T23:59:59.000Z
A dielectric-wall linear accelerator is improved by a high-voltage, fast rise-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface. 12 figs.
Caporaso, George J. (Livermore, CA); Sampayan, Stephen E. (Manteca, CA); Kirbie, Hugh C. (Dublin, CA)
1998-01-01T23:59:59.000Z
A dielectric-wall linear accelerator is improved by a high-voltage, fast rise-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface.
Murray, Richard M.
On the Control of Jump Linear Markov Systems with Markov State Estimation Vijay Gupta, Richard M of such a system and also solve the optimal LQR control problem for the case when the state estimate update uses. As an example of how jump linear Markov systems might be useful to model systems being controlled over a network
Lyapunov Functions in Piecewise Linear Systems: From Fixed Point to Limit Cycle
Yian Ma; Ruoshi Yuan; Yang Li; Ping Ao; Bo Yuan
2013-06-28T23:59:59.000Z
This paper provides a first example of constructing Lyapunov functions in a class of piecewise linear systems with limit cycles. The method of construction helps analyze and control complex oscillating systems through novel geometric means. Special attention is stressed upon a problem not formerly solved: to impose consistent boundary conditions on the Lyapunov function in each linear region. By successfully solving the problem, the authors construct continuous Lyapunov functions in the whole state space. It is further demonstrated that the Lyapunov functions constructed explain for the different bifurcations leading to the emergence of limit cycle oscillation.
Effects of time delay in feedback control of linear quantum systems
Kazunori Nishio; Kenji Kashima; Jun-ichi Imura
2008-11-27T23:59:59.000Z
We investigate feedback control of linear quantum systems subject to feedback-loop time delays. In particular, we examine the relation between the potentially achievable control performance and the time delays, and provide theoretical guidelines for the future experimental setup in two physical systems, which are typical in this research field. The evaluation criterion for the analysis is given by the optimal control performance formula, the derivation of which is from the classical control theoretic results about the input-output delay systems.
Mumby, Peter J.
by delay in a linearly controlled system Outline Sketch of modelled setup t Chaos Bifurcation analysis of an inverted pendulum that is balanced with linear feedback control. References ( www.enm.bris.ac.uk/anm) J cos (t) ¨(t) = 2 3 L F where F is a delayed linear proportional- plus-derivative feedback control
DualÂSamplingÂRate Moving Horizon Control of a Class of Linear Systems with Input SaturationÂsamplingÂrate moving horizon control scheme for a class of linear, continuousÂtime plants with strict input saturation, it is not computed by a simple linear feedback law, but as a solution of an optimal control problem. As a result
Dual-Sampling-Rate Moving Horizon Control of a Class of Linear Systems with Input Saturation and
Dual-Sampling-Rate Moving Horizon Control of a Class of Linear Systems with Input Saturation horizon control scheme for a class of linear, continuous-time plants with strict input saturation horizon control, robust, fast sampling, stability, linear sys- tems, input constraints 1 Introduction
Kaya, Yalcin
Appeared in: IMA Journal of Mathematical Control and Information. 12, 207-217, 1995. Linearized a practice to design control laws. In this paper, an analysis is given involving linear approxima- tion-time reachable sets of the nonlinear control system and its linear approximation. Behaviour of the nonlinear
Linear Response Calculations of Lattice Dynamics in Strongly Correlated Systems S.Y. Savrasov
Savrasov, Sergej Y.
electronic structure calculations has already led to new insights in long-standing prob- lemsLinear Response Calculations of Lattice Dynamics in Strongly Correlated Systems S.Y. Savrasov electrons and the local density functional theory of electronic structure. We apply the method to study
mn header will be provided by the publisher Linear Passive Stationary Scattering Systems
Rovnyak, James
mn header will be provided by the publisher Linear Passive Stationary Scattering Systems 26, Odessa 65020, Ukraine 2 Department of Mathematics, University of Virginia, P. O. Box 400137@farlep.net Corresponding author: e-mail: rovnyak@Virginia.edu e-mail: sergey saprikin@ukr.net Copyright line
ON HIGHER ORDER EMBEDDINGS OF FANO THREEFOLDS BY THE ANTICANONICAL LINEAR SYSTEM
Sommese, Andrew J.
ON HIGHER ORDER EMBEDDINGS OF FANO THREEFOLDS BY THE ANTICANONICAL LINEAR SYSTEM MAURO C order embeddings of projective manifolds. This is of importance in the understanding of higher order embeddings of the special varieties of ad- junction theory, which are usually bered by special Fano manifolds
ON HIGHER ORDER EMBEDDINGS OF FANO THREEFOLDS BY THE ANTICANONICAL LINEAR SYSTEM
Sommese, Andrew J.
ON HIGHER ORDER EMBEDDINGS OF FANO THREEFOLDS BY THE ANTICANONICAL LINEAR SYSTEM MAURO C order embeddings of projective manifolds. This is of importance in the understanding of higher order embeddings of the special varieties of adÂ junction theory, which are usually fibered by special Fano
Fast Jacobi-type Algorithm for Computing Distances Between Linear Dynamical Systems
Vidal, René
Fast Jacobi-type Algorithm for Computing Distances Between Linear Dynamical Systems Nicolas D Jacobi-type algorithm that solves this problem. Each step of the algorithm is equivalent to finding, in this paper, we introduce a fast and accurate Jacobi-type algorithm for computing alignment distances. Our
A Converse Lyapunov Theorem for Uncertain Switched Linear Systems Hai Lin and Panos J. Antsaklis
Antsaklis, Panos
A Converse Lyapunov Theorem for Uncertain Switched Linear Systems Hai Lin and Panos J. Antsaklis Abstract-- The main contribution of this paper is a converse Lyapunov theorem derived for a class switching laws implies the existence of a polyhedral Lyapunov function along with conic partition based
A REVIEW OF LINEAR RESPONSE THEORY FOR GENERAL DIFFERENTIABLE DYNAMICAL SYSTEMS.
#erentiable dynamical system, identify nonequilibÂ rium steady states (NESS), and study how these vary under the ''attractor'' corresponding to the NESS). If the chaotic hypothesis does not hold, two new phenomena may arise. The first is a violation of linear response in the sense that the NESS does not depend di
STABLE REDUCTION TO KKT SYSTEMS IN BARRIER METHODS FOR LINEAR AND QUADRATIC PROGRAMMING
Stanford University
-dual barrier methods for linear and quadratic programming. Following Freund and Jarre, we explore methods, y, z. Most authors eliminate z and/or x without further ado. Freund and Jarre [FJ95] first showed scaling into a KKT system involving a symmetric matrix K. We generalize Freund and Jarre's approach
Paris-Sud XI, Université de
-conservative mechanical systems is proposed. In particular, dry-friction non-linearities are considered although degrees-of-freedom example featuring dry-friction illustrates the method and highlights the effects of a turbomachinery blade, with dry-friction interfaces is proposed. In the latter, an original framework
COMPUTING AND DEFLATING EIGENVALUES WHILE SOLVING MULTIPLE RIGHT HAND SIDE LINEAR SYSTEMS WITH AN
Stathopoulos, Andreas
COMPUTING AND DEFLATING EIGENVALUES WHILE SOLVING MULTIPLE RIGHT HAND SIDE LINEAR SYSTEMS a new algorithm that computes eigenvalues and eigenvectors of a Her- mitian positive definite matrix applications, where hundreds of right hand sides may be needed. Specifically, about 70 eigenvectors
Minimax design of vibration absorbers for linear damped systems Brandon Brown, Tarunraj Singh
Singh, Tarunraj
Minimax design of vibration absorbers for linear damped systems Brandon Brown, Tarunraj Singh Ã Department of Mechanical and Aerospace Engineering, State University of New York at Buffalo, Buffalo, NY addresses the issue of design of a passive vibration absorber in the presence of uncertainties
Plug-and-play decentralized model predictive control for linear systems
Ferrari-Trecate, Giancarlo
1 Plug-and-play decentralized model predictive control for linear systems Stefano Riverso, Graduate to automatize the design of local controllers so that it can be carried out in parallel by smart actuators. In particular, local controllers exploit tube-based Model Predictive Control (MPC) in order to guarantee
The number of genotypic assignments on a genealogy II. Further results for linear systems
The number of genotypic assignments on a genealogy II. Further results for linear systems N. J known phenotypes could be calculated for an arbitrary genealogy. Here, we present further results for several regular genealogies constructed according to some specified recursive formulae and for which
Use of Linear Predictive Control for a Solar Electric Generating System
Wisconsin at Madison, University of
behavior can be used to design and operate plants. The solar power plant is characterized by significant1 Use of Linear Predictive Control for a Solar Electric Generating System Thorsten Stuetzle, Nathan Blair, William A. Beckman, John W. Mitchell Solar Energy Laboratory University of Wisconsin-Madison 1500
Smith, Zachary A.; Gorgulho, Alessandra A.; Bezrukiy, Nikita; McArthur, David [Department of Neurosurgery, UCLA Medical Center, Los Angeles, CA (United States); Agazaryan, Nzhde; Selch, Michael T. [Department of Radiation Oncology, UCLA Medical Center, Los Angeles, CA (United States); De Salles, Antonio A.F., E-mail: adesalles@mednet.ucla.edu [Department of Neurosurgery, UCLA Medical Center, Los Angeles, CA (United States); Department of Radiation Oncology, UCLA Medical Center, Los Angeles, CA (United States); West Los Angeles Veteran's Administration Hospital, Los Angeles, CA (United States)
2011-09-01T23:59:59.000Z
Purpose: Dedicated linear accelerator radiosurgery (D-LINAC) has become an important treatment for trigeminal neuralgia (TN). Although the use of gamma knife continues to be established, few large series exist using D-LINAC. The authors describe their results, comparing the effects of varied target and dose regimens. Methods and Materials: Between August 1995 and January 2008, 179 patients were treated with D-LINAC radiosurgery. Ten patients (5.58%) had no clinical follow-up. The median age was 74.0 years (range, 32-90 years). A total of 39 patients had secondary or atypical pain, and 130 had idiopathic TN. Initially, 28 patients received doses between 70 and 85 Gy, with the 30% isodose line (IDL) touching the brainstem. Then, using 90 Gy, 82 consecutive patients were treated with a 30% IDL and 59 patients with a 50% IDL tangential to the pons. Results: Of 169 patients, 134 (79.3%) experienced significant relief at a mean of 28.8 months (range, 5-142 months). Average time to relief was 1.92 months (range, immediate to 6 months). A total of 31 patients (19.0%) had recurrent pain at 13.5 months. Of 87 patients with idiopathic TN without prior procedures, 79 (90.8%) had initial relief. Among 28 patients treated with 70 Gy and 30% IDL, 18 patients (64.3%) had significant relief, and 10 (35.7%) had numbness. Of the patients with 90 Gy and 30% IDL at the brainstem, 59 (79.0%) had significant relief and 48.9% had numbness. Among 59 consecutive patients with similar dose but the 50% isodoseline at the brainstem, 49 patients (88.0%) had excellent/good relief. Numbness, averaging 2.49 on a subjective scale of 1 to 5, was experienced by 49.7% of the patients, Conclusions: Increased radiation dose and volume of brainstem irradiation may improve clinical outcomes with the trade-off of trigeminal dysfunction. Further study of the implications of dose and target are needed to optimize outcomes and to minimize complications.
AN ACCELERATOR-BASED NEUTRON MICROBEAM SYSTEM FOR STUDIES OF RADIATION EFFECTS
Brenner, David Jonathan
and David J. Brenner1 1 Radiological Research Accelerator Facility, Columbia University, Irvington, NY 10533 2010 A novel neutron microbeam is being developed at the Radiological Research Accelerator Facility on existing microbeam tech- niques at the Radiological Research Accelerator Facility (RARAF) of Columbia
Application of convolution theory for solving non-linear flow problems: gas flow systems
Mireles, Thomas Joseph
1995-01-01T23:59:59.000Z
. . . . . . . . . . . . 15 3. 2. 1 Generalized Analytical Solution for Real Gas Systems . . . . . . . . 15 3. 2. 2 Dry Gas Material Balance Relations: P(tn) - g(u) Identity. . . . . . 16 3. 3 Functional and Numerical Data Models for the Non-Linear CHAPTER IV Component... of the functions. " By applying this theorem and taking the Laplace transform of the right hand side of Eq. 3. 1 (expressed by Eq. 3. 3), we obtain Eq. 3. 4. Q(ft * fj)(t)) = ft(u) g(u) . where the non-linear transform function is given as g(u) = X(g(t)) . (3...
Optimal steering of a linear stochastic system to a final probability distribution
Yongxin Chen; Tryphon Georgiou; Michele Pavon
2014-08-10T23:59:59.000Z
We consider the problem to steer a linear dynamical system with full state observation from an initial gaussian distribution in state-space to a final one with minimum energy control. The system is stochastically driven through the control channels; an example for such a system is that of an inertial particle experiencing random "white noise" forcing. We show that a target probability distribution can always be achieved in finite time. The optimal control is given in state-feedback form and is computed explicitely by solving a pair of differential Lyapunov equations that are coupled through their boundary values. This result, given its attractive algorithmic nature, appears to have several potential applications such as to active control of nanomechanical systems and molecular cooling. The problem to steer a diffusion process between end-point marginals has a long history (Schr\\"odinger bridges) and therefore, the present case of steering a linear stochastic system constitutes a Schr\\"odinger bridge for possibly degenerate diffusions. Our results, however, provide the first implementable form of the optimal control for a general Gauss-Markov process. Illustrative examples of the optimal evolution and control for inertial particles and a stochastic oscillator are provided. A final result establishes directly the property of Schr\\"{o}dinger bridges as the most likely random evolution between given marginals to the present context of linear stochastic systems.
Laser-based proton acceleration on ultra-thin foil with a 100 TW class high intensity laser system
Marjoribanks, Robin S.
of electromagnetic fields in plasma, isotopes production or hadron therapy. The 100 TW class laser systemLaser-based proton acceleration on ultra-thin foil with a 100 TW class high intensity laser system. To characterize the plasma expansion, we monitor it with an imaging technique using a femtosecond laser probe
DIWAN,M.; MARCIANO,W.; WENG,W.; RAPARIA,D.
2003-04-21T23:59:59.000Z
This document describes the design of the accelerator and target systems for the AGS Super Neutrino Beam Facility. Under the direction of the Associate Laboratory Director Tom Kirk, BNL has established a Neutrino Working Group to explore the scientific case and facility requirements for a very long baseline neutrino experiment. Results of a study of the physics merit and detector performance was published in BNL-69395 in October 2002, where it was shown that a wide-band neutrino beam generated by a 1 MW proton beam from the AGS, coupled with a half megaton water Cerenkov detector located deep underground in the former Homestake mine in South Dakota would be able to measure the complete set of neutrino oscillation parameters: (1) precise determination of the oscillation parameters {Delta}m{sub 32}{sup 2} and sin{sup 2} 2{theta}{sub 32}; (2) detection of the oscillation of {nu}{sub {mu}}-{nu}{sub e} and measurement of sin{sup 2} 2{theta}{sub 13}; (3) measurement of {Delta}m{sub 21}{sup 2} sin 2{theta}{sub 12} in a {nu}{sub {mu}} {yields} {nu}{sub e} appearance mode, independent of the value of {theta}{sub 13}; (4) verification of matter enhancement and the sign of {Delta}m{sub 32}{sup 2}; and (5) determination of the CP-violation parameter {delta}{sub CP} in the neutrino sector. This report details the performance requirements and conceptual design of the accelerator and the target systems for the production of a neutrino beam by a 1.0 MW proton beam from the AGS. The major components of this facility include a new 1.2 GeV superconducting linac, ramping the AGS at 2.5 Hz, and the new target station for 1.0 MW beam. It also calls for moderate increase, about 30%, of the AGS intensity per pulse. Special care is taken to account for all sources of proton beam loss plus shielding and collimation of stray beam halo particles to ensure equipment reliability and personal safety. A preliminary cost estimate and schedule for the accelerator upgrade and target system are also included.
Chattopadhyay, S.
2011-01-01T23:59:59.000Z
500 MHz buncher is a 4-cell SCRF cavity in which the beam issection consists of two SCRF accelerating modules in whichoperating temperature for the SCRF cavities. A standard, 600
Topaloudis, A; Bellas, N; Jensen, L
The world’s largest research center in the domain of High Energy Physics (HEP) is the European Organization for Nuclear Research (CERN) whose main goal is to accelerate particles through a sequence of accelerators – accelerator complex – and bring them into collision in order to study the fundamental elements of matter and the forces acting between them. For controlling the accelerator complex, CERN needs several diagnostic tools to provide information about the beam’s attributes and one such system is the Fast Beam Current Transformer (FBCT) measuring system that provides bunch-by-bunch and total beam intensity information. The current hardware and firmware of the FBCT system has certain issues and lacks diagnostics as a lot of the calculations are done in an FPGA. In order to improve on this, the firmware was redesigned and simplified in order to increase its capabilities and provide the base of a unified FBCT measuring system that could be installed in several of CERN’s accelerator complex’s pa...
High brightness electron accelerator
Sheffield, Richard L. (Los Alamos, NM); Carlsten, Bruce E. (Los Alamos, NM); Young, Lloyd M. (Los Alamos, NM)
1994-01-01T23:59:59.000Z
A compact high brightness linear accelerator is provided for use, e.g., in a free electron laser. The accelerator has a first plurality of acclerating cavities having end walls with four coupling slots for accelerating electrons to high velocities in the absence of quadrupole fields. A second plurality of cavities receives the high velocity electrons for further acceleration, where each of the second cavities has end walls with two coupling slots for acceleration in the absence of dipole fields. The accelerator also includes a first cavity with an extended length to provide for phase matching the electron beam along the accelerating cavities. A solenoid is provided about the photocathode that emits the electons, where the solenoid is configured to provide a substantially uniform magnetic field over the photocathode surface to minimize emittance of the electons as the electrons enter the first cavity.
A temperature-mapping system for multi-cell SRF accelerating cavities
Ge, M; Furuta, F; Smith, E; Liepe, M; Posen, S; Padamsee, H; Hartill, D; Mi, X
2015-01-01T23:59:59.000Z
A Temperature mapping (T-map) system for Superconducting Radio Frequency (SRF) cavities consists of a thermometer array positioned precisely on an exterior cavity wall, capable of detecting small increases in temperature; therefore it is a powerful tool for research on the quality factor (Q0) of SRF cavities. A new multi-cell T-mapping system is has been developed at Cornell University. The system has nearly two thousand thermometers to cover 7-cell SRF cavities for Cornell ERL project. A new multiplexing scheme was adopted to reduce number of wires. A 1mK resolution of the temperature increase Delta T is achieved. A 9-cell cavity of TESLA geometry was tested with the T-map system. By converting Delta T to power loss and quality factor, it has been found that for this cavity, most surface losses were generated by the first cell when the accelerating gradient is increased above 15MV/m. The comparison of Q-value between with and without hotspots shows the heating on cavity wall degraded cavity Q0 about 1.65 tim...
NONE
1993-07-01T23:59:59.000Z
The Accelerator System Model (ASM) is a computer program developed to model proton radiofrequency accelerators and to carry out system level trade studies. The ASM FORTRAN subroutines are incorporated into an intuitive graphical user interface which provides for the {open_quotes}construction{close_quotes} of the accelerator in a window on the computer screen. The interface is based on the Shell for Particle Accelerator Related Codes (SPARC) software technology written for the Macintosh operating system in the C programming language. This User Manual describes the operation and use of the ASM application within the SPARC interface. The Appendix provides a detailed description of the physics and engineering models used in ASM. ASM Version 1.0 is joint project of G. H. Gillespie Associates, Inc. and the Accelerator Technology (AT) Division of the Los Alamos National Laboratory. Neither the ASM Version 1.0 software nor this ASM Documentation may be reproduced without the expressed written consent of both the Los Alamos National Laboratory and G. H. Gillespie Associates, Inc.
2012-01-01T23:59:59.000Z
Proposal for the award of a contract for the design, supply, installation and commissioning of Heating, Ventilation and Air-Conditioning (HVAC) systems for the PS accelerator infrastructure
California at Davis, University of
Light Source RF-gun Accelerating cavity for International Linear Collider Summary and Future work #12 Light Source RF-gun Accelerating cavity for International Linear Collider Summary and Future work #12;RF-gun Accelerating cavity for International Linear Collider Summary and Future work #12;Quadratric
Coherent Feedback Control of Linear Quantum Optical Systems via Squeezing and Phase Shift
Guofeng Zhang; Heung Wing Joseph Lee; Bo Huang; Hu Zhang
2012-06-16T23:59:59.000Z
The purpose of this paper is to present a theoretic and numerical study of utilizing squeezing and phase shift in coherent feedback control of linear quantum optical systems. A quadrature representation with built-in phase shifters is proposed for such systems. Fundamental structural characterizations of linear quantum optical systems are derived in terms of the new quadrature representation. These results reveal considerable insights of issue of physical realizability of such quantum systems. The problem of coherent quantum LQG feedback control studied in [35,50] is re-investigated in depth. Firstly, the optimization methods in [35,50] are extended to a multi-step optimization algorithm which utilizes ideal squeezers. Secondly, a two-stage optimization approach is proposed on the basis of controller parametrization. Numerical studies show that closed-loop systems designed via the second approach may offer LQG control performance even better than that when the closed-loop systems are in the vacuum state. When ideal squeezers in a close-loop system are replaced by (more realistic) degenerate parametric amplifiers, a sufficient condition is derived for the asymptotic stability of the resultant new closed-loop system; the issue of performance convergence is also discussed in the LQG control setting.
Yoshio Uwano; Hiromi Yuya
2008-07-25T23:59:59.000Z
In the paper of Uwano [Czech. J. of Phys., vol.56, pp.1311-1316 (2006)], a gradient system is found on the space of density matrices endowed with the quantum SLD Fisher metric (to be referred to as the quantum information space) that realizes a generalization of a gradient system on the space of multinomial distributions studied by Nakamura [Japan J. Indust. Appl. Math., vol.10, pp.179-189 (1993)]. On motived by those papers, the present paper aims to construct a gradient system on the quantum information space that realizes the Karmarkar flow, the continuous limit of the Karmarkar projective scaling algorithm for linear programming.
A Novel MagPipe Pipeline transportation system using linear motor drives
Fang, J.R.; Montgomery, D.B.; Roderick, L. [Magplane Technology Inc., Littleton, MA (United States)
2009-11-15T23:59:59.000Z
A novel capsule pipeline transportation system using linear motor drives, called Magplane MagPipe, is under development with the intention to replace trucks and railways for hauling materials from the mine to the rail head, power plant, or processing plant with reduced operating cost and energy consumption. The initial demonstration of a MagPipe line in Inner Mongolia will be a 500-m-long double-pipe coal transport system with the design transportation capacity of 3 Mega-Mg per year. The pipeline consists of 6-m-long plastic pipe modules with an I-beam suspension system inside the pipe to carry sets of five coupled capsules. The pipe will also contain noncontinuous motor winding modules spaced at 50-m intervals. A set of Halbach-arrayed permanent magnets on the bottom of the capsules interact with the linear motor windings to provide propulsion. The motor is driven by variable frequency drives outside the pipe to control the speed. This paper briefly describes the overall MagPipe pipeline transportation system, including the preliminary conclusions of the linear synchronous motor analysis.
YÃ¼ksel, Serdar
notion of controllability, these form the essence of modern linear control theory. In this technical note states intact. Furthermore, with the increasing emphasis on networked control systems, it has been realized that the controllability and observability concepts for linear systems with controllers having
Ayati, Moosa [Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario (Canada); Faculty of Electrical and Computer Engineering, K. N. Toosi University of Technology, Tehran (Iran, Islamic Republic of); Alwan, Mohamad; Liu Xinzhi [Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario (Canada); Khaloozadeh, Hamid [Faculty of Electrical and Computer Engineering, K. N. Toosi University of Technology, Tehran (Iran, Islamic Republic of)
2011-11-30T23:59:59.000Z
State observation (estimation) is a very important issue in system analysis and control. This paper develops a new observer called Stochastic Adaptive Impulsive Observer (SAIO) for the state estimation of impulsive systems. The proposed observer is applicable to linear and nonlinear stochastic impulsive systems. In addition, the effect of parametric uncertainty is considered and unknown parameters of the system are estimated by suitable adaptation laws. Impulsive system theory, particularly stochastic Lyapunov-like function, is used to analyze the stability and convergence of the state estimations. The main advantages of the proposed observer are: 1) it gives continuous estimation from discrete time measurements of the system output, and 2) it is useful for state estimation when continuous measurements are impossible or expensive. Simulation results show the effectiveness of the proposed observer and we believe that it has many applications in control and estimation theories.
Operational status of the Brookhaven National Laboratory Accelerator Test Facility
Batchelor, K.; Ben-Zvi, I.; Fernow, R.C.; Fischer, A.S.; Gallardo, J.; Jialin, Xie; Kirk, H.G.; Malone, R.G.; Parsa, Z.; Palmer, R.B.; Rao, T.; Rogers, J.; Sheehan, J.; Tsang, T.Y.F.; Ulc, S.; van Steenbergen, A.; Woodle, M.; Zhang, R.S. (Brookhaven National Lab., Upton, NY (USA)); Bigio, I.; Kurnit, N.; Shimada, T. (Los Alamos National Lab., NM (USA)); McDonald, K.T.; Russel, D.P. (Princeton Univ., NJ (USA)); Jiang,
1990-01-01T23:59:59.000Z
Initial design parameters and early operational results of a 50 MeV high brightness electron linear accelerator are described. The system utilizes a radio frequency electron gun operating at a frequency of 2.856 GHz and a nominal output energy of 4.5 MeV followed by two, 2{pi}/3 mode, disc loaded, traveling wave accelerating sections. The gun cathode is photo excited with short (6 psec) laser pulses giving design peak currents of a few hundred amperes. The system will be utilized to carry out infra-red FEL studies and investigation of new high gradient accelerating structures.
Accelerator Development @ Daresbury Laboratory
-injectors Superconducting RF acceleration Cryogenic systems Advanced diagnostics Free Electron Lasers Photon beam radioisotopes. 2 Treatment & Diagnostics #12;Basic Accelerator Configuration 3 Beam Source Low Energy Capture electron beam technology development. 4 Booster Compressor IR-FEL Photoinjector Laser Linac Acceleration
Wechsler, Risa H.
#12;Accelerator Physics Accelerators form the backbone of SLAC's on-site experimental program. Research at SLAC is continually improving accelerators, both here and at other laboratories, and paving the way for a new generation of particle acceleration technology. SLAC's famous linear accelerator
Synthesis of Optimal Ensemble Controls for Linear Systems using the Singular Value Decomposition
Zlotnik, Anatoly
2011-01-01T23:59:59.000Z
An emerging and challenging area in mathematical control theory called Ensemble Control encompasses a class of problems that involves the guidance of an uncountably infinite collection of structurally identical dynamical systems, which are indexed by a parameter set, by applying the same open-loop control. The subject originates from the study of complex spin dynamics in Nuclear Magnetic Resonance (NMR) spectroscopy and imaging (MRI). A fundamental question concerns ensemble controllability, which determines the existence of controls that transfer the system between desired initial and target states. For ensembles of finite-dimensional time-varying linear systems, the necessary and sufficient controllability conditions and analytical optimal control laws have been shown to depend on the singular system of the operator characterizing the system dynamics. Because analytical solutions are available only in the simplest cases, there is a need to develop numerical methods for synthesizing these controls. We introd...
Frequency response of linear systems from transient data utilizing the digital computer
Roberts, Edward E
1956-01-01T23:59:59.000Z
- nautical Science, Vol. XVII (July 1950), p. 446. M. E. LaVerne and A. S. Boksenbom, "Frequency Response of Linear Systems from Transient Data, " NACA Report 977 (1950). H. J. Curfman and R. A. Gardiner, "Method for Determining the Frequency Response...- quency ur by: Y(j ar) = ( Y~ e&& Ytl e Jm'(~) + Yt2 e j3ar(~) dt Ch "t Yt3e j3m(+) + YtA e j7 (~) + t mt (3A) The addition of these vectors results in a vector defining the I response characteristics of the element or system at the forcing fre...
Accelerating Structure design and fabrication For KIPT and PAL XFEL
Hou, Mi; Pei, Shilun
2014-01-01T23:59:59.000Z
ANL and the National Science Center "Kharkov Institute of Physics Technology" (NSC KIPT, Kharkov, Ukraine) jointly proposed to design and build a 100MeV/100KW linear accelerator which will be used to drive the neutron source subcritical assembly. Now the linac was almost assembled in KIPT by the team from Institute of High Energy Physics (IHEP, Beijing, China). The design and measurement result of the accelerating system of the linac will be described in this paper.
Final technical report [ACCELERATED MOLECULAR DYNAMICS SIMULATIONS OF REACTIVE HYDROCARBON SYSTEMS
Stuart, Steven J.
2014-02-25T23:59:59.000Z
The research activities in this project consisted of four different sub-projects. Three different accelerated dynamics techniques (parallel replica dynamics, hyperdynamics, and temperature-accelerated dynamics) were applied to the modeling of pyrolysis of hydrocarbons. In addition, parallel replica dynamics was applied to modeling of polymerization.
Linear motor drive system for continuous-path closed-loop position control of an object
Barkman, William E. (Oak Ridge, TN)
1980-01-01T23:59:59.000Z
A precision numerical controlled servo-positioning system is provided for continuous closed-loop position control of a machine slide or platform driven by a linear-induction motor. The system utilizes filtered velocity feedback to provide system stability required to operate with a system gain of 100 inches/minute/0.001 inch of following error. The filtered velocity feedback signal is derived from the position output signals of a laser interferometer utilized to monitor the movement of the slide. Air-bearing slides mounted to a stable support are utilized to minimize friction and small irregularities in the slideway which would tend to introduce positioning errors. A microprocessor is programmed to read command and feedback information and converts this information into the system following error signal. This error signal is summed with the negative filtered velocity feedback signal at the input of a servo amplifier whose output serves as the drive power signal to the linear motor position control coil.
A practical target system for accelerator-based BNCT which may effectively double the dose rate
Brenner, David Jonathan
. Randers-Pehrsona) and D. J. Brenner Center for Radiological Research, Radiological Research Accelerator Facility, Columbia University, Irvington, New York 10533 Received 27 May 1997; accepted for publication 31
APT accelerator. Topical report
Lawrence, G.; Rusthoi, D. [comp.] [ed.
1995-03-01T23:59:59.000Z
The Accelerator Production of Tritium (APT) project, sponsored by Department of Energy Defense Programs (DOE/DP), involves the preconceptual design of an accelerator system to produce tritium for the nation`s stockpile of nuclear weapons. Tritium is an isotope of hydrogen used in nuclear weapons, and must be replenished because of radioactive decay (its half-life is approximately 12 years). Because the annual production requirements for tritium has greatly decreased since the end of the Cold War, an alternative approach to reactors for tritium production, based on a linear accelerator, is now being seriously considered. The annual tritium requirement at the time this study was undertaken (1992-1993) was 3/8 that of the 1988 goal, usually stated as 3/8-Goal. Continued reduction in the number of weapons in the stockpile has led to a revised (lower) production requirement today (March, 1995). The production requirement needed to maintain the reduced stockpile, as stated in the recent Nuclear Posture Review (summer 1994) is approximately 3/16-Goal, half the previous level. The Nuclear Posture Review also requires that the production plant be designed to accomodate a production increase (surge) to 3/8-Goal capability within five years, to allow recovery from a possible extended outage of the tritium plant. A multi-laboratory team, collaborating with several industrial partners, has developed a preconceptual APT design for the 3/8-Goal, operating at 75% capacity. The team has presented APT as a promising alternative to the reactor concepts proposed for Complex-21. Given the requirements of a reduced weapons stockpile, APT offers both significant safety, environmental, and production-fexibility advantages in comparison with reactor systems, and the prospect of successful development in time to meet the US defense requirements of the 21st Century.
Resurgence, Stokes phenomenon and alien derivatives for level-one linear differential systems
Loday-Richaud, Michèle
2010-01-01T23:59:59.000Z
A precise description of the singularities of the Borel transform of solutions of a level-one linear differential system is deduced from a proof of the summable-resurgence of the solutions by the perturbative method of J. \\'Ecalle. Then we compare the meromorphic classification (Stokes phenomenon) from the viewpoint of the Stokes cocycle and the viewpoint of alien derivatives. We make explicit the Stokes-Ramis matrices as functions of the connection constants in the Borel plane and we develop two examples. No assumption of genericity is made.
Conceptual design of minor actinides burner with an accelerator-driven subcritical system.
Cao, Y.; Gohar, Y. (Nuclear Engineering Division)
2011-11-04T23:59:59.000Z
In the environmental impact study of the Yucca Mountain nuclear waste repository, the limit of spent nuclear fuel (SNF) for disposal is assessed at 70,000 metric tons of heavy metal (MTHM), among which 63,000 MTHM are the projected SNF discharge from U.S. commercial nuclear power plants though 2011. Within the 70,000 MTHM of SNF in storage, approximately 115 tons would be minor actinides (MAs) and 585 tons would be plutonium. This study describes the conceptual design of an accelerator-driven subcritical (ADS) system intended to utilize (burn) the 115 tons of MAs. The ADS system consists of a subcritical fission blanket where the MAs fuel will be burned, a spallation neutron source to drive the fission blanket, and a radiation shield to reduce the radiation dose to an acceptable level. The spallation neutrons are generated from the interaction of a 1 GeV proton beam with a lead-bismuth eutectic (LBE) or liquid lead target. In this concept, the fission blanket consists of a liquid mobile fuel and the fuel carrier can be LBE, liquid lead, or molten salt. The actinide fuel materials are dissolved, mixed, or suspended in the liquid fuel carrier. Therefore, fresh fuel can be fed into the fission blanket to adjust its reactivity and to control system power during operation. Monte Carlo analyses were performed to determine the overall parameters of an ADS system utilizing LBE as an example. Steady-state Monte Carlo simulations were studied for three fission blanket configurations that are similar except that the loaded amount of actinide fuel in the LBE is either 5, 7, or 10% of the total volume of the blanket, respectively. The neutron multiplication factor values of the three configurations are all approximately 0.98 and the MA initial inventories are each approximately 10 tons. Monte Carlo burnup simulations using the MCB5 code were performed to analyze the performance of the three conceptual ADS systems. Preliminary burnup analysis shows that all three conceptual ADS systems consume about 1.2 tons of actinides per year and produce 3 GW thermal power, with a proton beam power of 25 MW. Total MA fuel that would be consumed in the first 10 years of operation is 9.85, 11.80, or 12.68 tons, respectively, for the systems with 5, 7, or 10% actinide fuel particles loaded in the LBE. The corresponding annual MA fuel transmutation rate after reaching equilibrium at 10 years of operation is 0.83, 0.94, or 1.02 tons/year, respectively. Assuming that the ADS systems can be operated for 35 full-power years, the total MAs consumed in the three ADS systems are 30.6, 35.3, and 37.2 tons, respectively. For the three configurations, it is estimated that 3.8, 3.3, or 3.1 ADS system units are required to utilize the entire 115 tons of MA fuel in the SNF inventory, respectively.
Chintala, Rohit
2012-10-19T23:59:59.000Z
Numerical methods of designing control systems are currently an active area of research. Convex optimization with linear matrix inequalities (LMIs) is one such method. Control objectives like minimizing the H_2, H_infinity norms, limiting...
Entanglement of Accelerating Particles
W. L. Ku; M. -C. Chu
2007-09-03T23:59:59.000Z
We study how the entanglement of a maximally entangled pair of particles is affected when one or both of the pair are uniformly accelerated, while the detector remains in an inertial frame. We find that the entanglement is unchanged if all degrees of freedom are considered. However, particle pairs are produced, and the entanglements of different bipartite systems may change with the acceleration. In particular, the entanglement between accelerating fermions is transferred preferentially to the produced antiparticles when the acceleration is large, and the entanglement transfer is complete when the acceleration approaches infinity. However, for scalar particles, no entanglement transfer to the antiparticles is observed.
Design optimization of the International Linear Collider Final Focus System with a long L*
Plassard, Fabien
This Master's Thesis work has been done in the Aerospace Engineering master's programme framework and carried out at the European Organization for Nuclear Research (CERN). It was conducted under the 500 GeV e-e+ International Linear Collider (ILC) study and focused on the design and performance optimization of the Final Focus System (FFS). The purpose of the final focus system of the future linear colliders (ILC and CLIC) is to demagnify the beam to the required transverse size at the interaction point (IP). The FFS is designed for a flat-beam in a compact way based on a local chromaticity correction which corrects both horizontal and vertical chromaticities simultaneously. An alternative FFS configuration based on the traditional scheme with two dedicated chromatic correction sections for horizontal and vertical chromaticities and a long L * option has been developed. A longer free space between the last quadrupole and the IP allows to place the last quadrupole on a stable ground, with fewer engineering ...
Accelerators and the Accelerator Community
Malamud, Ernest
2009-01-01T23:59:59.000Z
for a PhD in accelerator physics was by E.O. Lawrence.of Beams) organizes accelerator physics sessions at APSstudents specializing in accelerator physics are not being “
SNEAP 80: symposium of Northeastern Accelerator personnel
Billen, J.H. (ed.) ed.
1980-01-01T23:59:59.000Z
Reports of operations are presented for twenty-seven facilities, along with reports on accelerators in progress, ion sources, insulating gases, charging systems, stripping foils, accelerating tubes, and upgraded accelerator systems. (GHT)
Accelerator driven production of tritium: target and blanket design
Ragusa, Jean Concetto
1996-01-01T23:59:59.000Z
of neutrons in the 'target' and the use of these neutrons in the 'blanket assembly'. The systems described in this thesis employ a linear accelerator (1 GeV protons, I 00 mA beam current), lead targets for the production of neutrons via spallation reactions...
Kinetic approaches to particle acceleration at cosmic ray modified shocks
Elena Amato; Pasquale Blasi; Stefano Gabici
2008-01-09T23:59:59.000Z
Kinetic approaches provide an effective description of the process of particle acceleration at shock fronts and allow to take into account the dynamical reaction of the accelerated particles as well as the amplification of the turbulent magnetic field as due to streaming instability. The latter does in turn affect the maximum achievable momentum and thereby the acceleration process itself, in a chain of causality which is typical of non-linear systems. Here we provide a technical description of two of these kinetic approaches and show that they basically lead to the same conclusions. In particular we discuss the effects of shock modification on the spectral shape of the accelerated particles, on the maximum momentum, on the thermodynamic properties of the background fluid and on the escaping and advected fluxes of accelerated particles.
Size reduction of high- and low-moisture corn stalks by linear knife grid system
Womac, A.R. [University of Tennessee; Igathinathane, C. [Mississippi State University (MSU); Sokhansanj, Shahabaddine [ORNL; Narayan, S. [First American Scientific Co.
2009-04-01T23:59:59.000Z
High- and low-moisture corn stalks were tested using a linear knife grid size reduction device developed for first-stage size reduction. The device was used in conjunction with a universal test machine that quantified shearing stress and energy characteristics for forcing a bed of corn stalks through a grid of sharp knives. No published engineering performance data for corn stover with similar devices are available to optimize performance; however, commercial knife grid systems exist for forage size reduction. From the force displacement data, mean and maximum ultimate shear stresses, cumulative and peak mass-based cutting energies for corn stalks, and mean new surface area-based cutting energies were determined from 4 5 refill runs at two moisture contents (78.8% and 11.3% wet basis), three knife grid spacings (25.4, 50.8, and 101.6 mm), and three bed depths (50.8, 101.6, and 152.4 mm). In general, the results indicated that peak failure load, ultimate shear stress, and cutting energy values varied directly with bed depth and inversely with knife grid spacing. Mean separation analysis established that high- and low-moisture conditions and bed depths 101.6 mm did not differ significantly (P < 0.05) for ultimate stress and cutting energy values, but knife grid spacing were significantly different. Linear knife grid cutting energy requirements for both moisture conditions of corn stalks were much smaller than reported cutting energy requirements. Ultimate shear stress and cutting energy results of this research should aid the engineering design of commercial scale linear knife gird size reduction equipment for various biomass feedstocks.
Revised 1/17/02 Physics 575 Accelerator Physics and
Revised 1/17/02 Physics 575 Accelerator Physics and Technologies for Linear Colliders (Winter .......................................................................................2-38 #12;2-1 Accelerator Physics and Technologies for Linear Colliders (Winter 2002) Kwang-Je Kim 2-linear resonances....................................................2-21 2.3 Acceleration and longitudinal motion
Lower Bounds on Complexity of Lyapunov Functions for Switched Linear Systems
Amir Ali Ahmadi; Raphael Jungers
2015-04-15T23:59:59.000Z
We show that for any positive integer $d$, there are families of switched linear systems---in fixed dimension and defined by two matrices only---that are stable under arbitrary switching but do not admit (i) a polynomial Lyapunov function of degree $\\leq d$, or (ii) a polytopic Lyapunov function with $\\leq d$ facets, or (iii) a piecewise quadratic Lyapunov function with $\\leq d$ pieces. This implies that there cannot be an upper bound on the size of the linear and semidefinite programs that search for such stability certificates. Several constructive and non-constructive arguments are presented which connect our problem to known (and rather classical) results in the literature regarding the finiteness conjecture, undecidability, and non-algebraicity of the joint spectral radius. In particular, we show that existence of an extremal piecewise algebraic Lyapunov function implies the finiteness property of the optimal product, generalizing a result of Lagarias and Wang. As a corollary, we prove that the finiteness property holds for sets of matrices with an extremal Lyapunov function belonging to some of the most popular function classes in controls.
Optimal steering of a linear stochastic system to a final probability distribution, part II
Yongxin Chen; Tryphon Georgiou; Michele Pavon
2014-10-13T23:59:59.000Z
We consider the problem of minimum energy steering of a linear stochastic system to a final prescribed distribution over a finite horizon and to maintain a stationary distribution over an infinite horizon. We present sufficient conditions for optimality in terms of a system of dynamically coupled Riccati equations in the finite horizon case and algebraic in the stationary case. We then address the question of feasibility for both problems. For the finite-horizon case, provided the system is controllable, we prove that without any restriction on the directionality of the stochastic disturbance it is always possible to steer the state to any arbitrary Gaussian distribution over any specified finite time-interval. For the stationary infinite horizon case, it is not always possible to maintain the state at an arbitrary Gaussian distribution through constant state-feedback. It is shown that covariances of admissible stationary Gaussian distributions are characterized by a certain Lyapunov-like equation. We finally present an alternative to solving the system of coupled Riccati equations, by expressing the optimal controls in the form of solutions to (convex) semi-definite programs for both cases. We conclude with an example to steer the state covariance of the distribution of inertial particles to an admissible stationary Gaussian distribution over a finite interval, to be maintained at that stationary distribution thereafter by constant-gain state-feedback control.
Design of an electromagnetic accelerator for turbulent hydrodynamic mix studies
Susoeff, A.R.; Hawke, R.S.; Morrison, J.J.; Dimonte, G.; Remington, B.A.
1993-12-08T23:59:59.000Z
An electromagnetic accelerator in the form of a linear electric motor (LEM) has been designed to achieve controlled acceleration profiles of a carriage containing hydrodynamically unstable fluids for the investigation of the development of turbulent mix. The Rayleigh- Taylor instability is investigated by accelerating two dissimilar density fluids using the LEM to achieve a wide variety of acceleration and deceleration profiles. The acceleration profiles are achieved by independent control of rail and augmentation currents. A variety of acceleration-time profiles are possible including: (1) constant, (2) impulsive and (3) shaped. The LEM and support structure are a robust design in order to withstand high loads with deflections and to mitigate operational vibration. Vibration of the carriage during acceleration could create artifacts in the data which would interfere with the intended study of the Rayleigh-Taylor instability. The design allows clear access for diagnostic techniques such as laser induced fluorescence radiography, shadowgraphs and particle imaging velocimetry. Electromagnetic modeling codes were used to optimize the rail and augmentation coil positions within the support structure framework. Results of contemporary studies for non-arcing sliding contact of solid armatures are used for the design of the driving armature and the dynamic electromagnetic braking system. A 0. 6MJ electrolytic capacitor bank is used for energy storage to drive the LEM. This report will discuss a LEM design which will accelerate masses of up to 3kg to a maximum of about 3000g{sub o}, where g{sub o} is accelerated due to gravity.
ILC Reference Design Report Volume 3 - Accelerator
Phinney, Nan; Walker, Nicholas
2007-01-01T23:59:59.000Z
The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a total footprint of about 31 km and is designed for a peak luminosity of 2x10^34 cm^-2 s^-1. The complex includes a polarized electron source, an undulator-based positron source, two 6.7 km circumference damping rings, two-stage bunch compressors, two 11 km long main linacs and a 4.5 km long beam delivery system. This report is Volume III (Accelerator) of the four volume Reference Design Report, which describes the design and cost of the ILC.
On the optimal feedback control of linear quantum systems in the presence of thermal noise
Marco G. Genoni; Stefano Mancini; Alessio Serafini
2013-04-27T23:59:59.000Z
We study the possibility of taking bosonic systems subject to quadratic Hamiltonians and a noisy thermal environment to non-classical stationary states by feedback loops based on weak measurements and conditioned linear driving. We derive general analytical upper bounds for the single mode squeezing and multimode entanglement at steady state, depending only on the Hamiltonian parameters and on the number of thermal excitations of the bath. Our findings show that, rather surprisingly, larger number of thermal excitations in the bath allow for larger steady-state squeezing and entanglement if the efficiency of the optimal continuous measurements conditioning the feedback loop is high enough. We also consider the performance of feedback strategies based on homodyne detection and show that, at variance with the optimal measurements, it degrades with increasing temperature.
Direct-Steam Linear Fresnel Performance Model for NREL's System Advisor Model
Wagner, M. J.; Zhu, G.
2012-09-01T23:59:59.000Z
This paper presents the technical formulation and demonstrated model performance results of a new direct-steam-generation (DSG) model in NREL's System Advisor Model (SAM). The model predicts the annual electricity production of a wide range of system configurations within the DSG Linear Fresnel technology by modeling hourly performance of the plant in detail. The quasi-steady-state formulation allows users to investigate energy and mass flows, operating temperatures, and pressure drops for geometries and solar field configurations of interest. The model includes tools for heat loss calculation using either empirical polynomial heat loss curves as a function of steam temperature, ambient temperature, and wind velocity, or a detailed evacuated tube receiver heat loss model. Thermal losses are evaluated using a computationally efficient nodal approach, where the solar field and headers are discretized into multiple nodes where heat losses, thermal inertia, steam conditions (including pressure, temperature, enthalpy, etc.) are individually evaluated during each time step of the simulation. This paper discusses the mathematical formulation for the solar field model and describes how the solar field is integrated with the other subsystem models, including the power cycle and optional auxiliary fossil system. Model results are also presented to demonstrate plant behavior in the various operating modes.
in microelectromechanical systems (MEMS) was first proposed for amplification of harmonically excited os- cillators in [1310 JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 16, NO. 2, APRIL 2007 Linear and Nonlinear Tuning of Parametrically Excited MEMS Oscillators Barry E. DeMartini, Student Member, IEEE, Jeffrey F
Accelerators and the Accelerator Community
Malamud, Ernest
2009-01-01T23:59:59.000Z
such as the International Linear Collider (ILC). In 2008, acollider: the International Linear Collider (ILC). Just what
Microelectromechanical acceleration-sensing apparatus
Lee, Robb M. (Albuquerque, NM); Shul, Randy J. (Albuquerque, NM); Polosky, Marc A. (Albuquerque, NM); Hoke, Darren A. (Albuquerque, NM); Vernon, George E. (Rio Rancho, NM)
2006-12-12T23:59:59.000Z
An acceleration-sensing apparatus is disclosed which includes a moveable shuttle (i.e. a suspended mass) and a latch for capturing and holding the shuttle when an acceleration event is sensed above a predetermined threshold level. The acceleration-sensing apparatus provides a switch closure upon sensing the acceleration event and remains latched in place thereafter. Examples of the acceleration-sensing apparatus are provided which are responsive to an acceleration component in a single direction (i.e. a single-sided device) or to two oppositely-directed acceleration components (i.e. a dual-sided device). A two-stage acceleration-sensing apparatus is also disclosed which can sense two acceleration events separated in time. The acceleration-sensing apparatus of the present invention has applications, for example, in an automotive airbag deployment system.
SLAC linear collider: the machine, the physics, and the future
Richter, B.
1981-11-01T23:59:59.000Z
The SLAC linear collider, in which beams of electrons and positrons are accelerated simultaneously, is described. Specifications of the proposed system are given, with calculated preditions of performance. New areas of research made possible by energies in the TeV range are discussed. (GHT)
Krishnan, Mahadevan; Elliott, Kristi Wilson; Madden, Robert E. [Alameda Applied Sciences Corporation, San Leandro, California 94577 (United States); Coleman, P. L. [Evergreen Hill Sciences, Philomath, Oregon 97370 (United States); Thompson, John R. [812 Temple Street, San Diego, California 92106 (United States); Bixler, Alex [Space Sciences Laboratory, University of California, Berkeley, Berkeley, California 94720 (United States); Lamppa, D. C.; McKenney, J. L.; Strizic, T.; Johnson, D.; Johns, O.; Vigil, M. P.; Jones, B.; Ampleford, D. J.; Savage, M. E.; Cuneo, M. E.; Jones, M. C. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)
2013-06-15T23:59:59.000Z
Tests are ongoing to conduct {approx}20 MA z-pinch implosions on the Z accelerator at Sandia National Laboratory using Ar, Kr, and D{sub 2} gas puffs as the imploding loads. The relatively high cost of operations on a machine of this scale imposes stringent requirements on the functionality, reliability, and safety of gas puff hardware. Here we describe the development of a prototype gas puff system including the multiple-shell nozzles, electromagnetic drivers for each nozzle's valve, a UV pre-ionizer, and an inductive isolator to isolate the {approx}2.4 MV machine voltage pulse present at the gas load from the necessary electrical and fluid connections made to the puff system from outside the Z vacuum chamber. This paper shows how the assembly couples to the overall Z system and presents data taken to validate the functionality of the overall system.
Zamantzas, C; Dehning, B
2006-01-01T23:59:59.000Z
The superconducting Large Hadron Collider (LHC) under construction at the European Organisation for Nuclear Research (CERN) is an accelerator unprecedented in terms of beam energy, particle production rate and also in the potential of self-destruction. Its operation requires a large variety of instrumentation, not only for the control of the beams, but also for the protection of the complex hardware systems. The Beam Loss Monitoring (BLM) system has to prevent the superconducting magnets from becoming normal conducting and protect the machine components against damages making it one of the most critical elements for the protection of the LHC. For its operation, the system requires 3600 detectors to be placed at various locations around the 27 km ring. The measurement system is sub-divided to the tunnel electronics, which are responsible for acquiring, digitising and transmitting the data, and the surface electronics, which receive the data via 2 km optical data links, process, analyze, store and issue warning...
Gajic, Zoran
function impulse. (b) Find and plot the step response using the function step. (c) Find the zero) The unit step response. Plot the corresponding output variables. (e) Let the initial system condition be i8.7.2 Experiment 2--Response of Continuous Systems Part 1. Consider a continuous-time linear system
Simulations of flame acceleration and deflagration-to-detonation transitions in methane-air systems
Kessler, D.A.; Gamezo, V.N.; Oran, E.S. [Laboratory for Computational Physics and Fluid Dynamics, Naval Research Laboratory, Washington, DC (United States)
2010-11-15T23:59:59.000Z
Flame acceleration and deflagration-to-detonation transitions (DDT) in large obstructed channels filled with a stoichiometric methane-air mixture are simulated using a single-step reaction mechanism. The reaction parameters are calibrated using known velocities and length scales of laminar flames and detonations. Calculations of the flame dynamics and DDT in channels with obstacles are compared to previously reported experimental data. The results obtained using the simple reaction model qualitatively, and in many cases, quantitatively match the experiments and are found to be largely insensitive to small variations in model parameters. (author)
A Parallel Modified Lagrangian Method for an Optimal Control Problem of a Linear Distributed@informatik.uni-halle.de Abstract We consider an optimal control problem for a Hilbert space valued linear* * stochastic Optimization, Control, Parallel Algorithms AMS Classification: 65Y05, 93E20, 93E23 1 Introduction
Klystron Linearizer for Use with 1.2 MW 476 MHz Klystrons in PEP-II RF Systems
Fox, J.; Mastorides, T.; Teytelman, D.; Van Winkle, D.; Zhou, Y.; /SLAC; Gallo, A.; /Frascati
2005-06-15T23:59:59.000Z
The direct and comb loop feedback around the RF cavities in PEP-II is critical in reducing longitudinal instabilities driven by the cavity impedance. The non-linear 1.2 MW klystron is in the signal path for these feedback loops. As a result, the effective small-signal gain of the klystron at 85% saturation reduces the impedance control by factors of 5 to 20 as compared to a linear power amplifier. A klystron linearizer circuit has been developed which operates in series with the power amplifier and acts to equalize the small and large signal gains through the combination. The technique must implement a 1 MHz linear control bandwidth over roughly 15 dB of RF signal level variation. The dynamics of this system is operating point dependent, and the channel must have dynamic gain compensation to keep the linearity compensation loop stable over changes in operating point. The design of this non-linear signal processing channel (incorporating RF and DSP techniques) and measured results from full-power klystron testing are presented.
Full Diversity Codes for MISO Systems Equipped with Linear or ML Detectors
Liu, Jing; Wong, Kon Max
2008-01-01T23:59:59.000Z
In this paper, a general criterion for space time block codes (STBC) to achieve full-diversity with a linear receiver is proposed for a wireless communication system having multiple transmitter and single receiver antennas (MISO). Particularly, the STBC with Toeplitz structure satisfies this criterion and therefore, enables full-diversity. Further examination of this Toeplitz STBC reveals the following important properties: a) The symbol transmission rate can be made to approach unity. b) Applying the Toeplitz code to any signalling scheme having nonzero distance between the nearest constellation points results in a non-vanishing determinant. In addition, if QAM is used as the signalling scheme, then for independent MISO flat fading channels, the Toeplitz codes is proved to approach the optimal diversity-vs-multiplexing tradeoff with a ZF receiver when the number of channel uses is large. This is, so far, the first non-orthogonal STBC shown to achieve the optimal tradeoff for such a receiver. On the other han...
The International Linear Collider
Jim Brau; Paul Grannis; Mike Harrison; Michael Peskin; Marc Ross; Harry Weerts
2013-04-09T23:59:59.000Z
We present a brief summary of the International Linear Collider as documented in the 2013 Technical Design Report. The Technical Design Report has detailed descriptions of the accelerator baseline design for a 500 GeV e+e- linear collider, the R&D program that has demonstrated its feasibility, the physics goals and expected sensitivities, and the description of the ILD and SiD detectors and their capabilities.
Barth, Eric J.
reservoir gas flow line 4-way proportional valve gas actuator actuator output shaft VC controlled volumeAbstract-- Pneumatic systems are highly non-linear by their nature. Despite their many advantages significant energy savings. They used two three- way spool valves instead of a conventional four
Beam-driven acceleration in ultra-dense plasma media
Shin, Young-Min [Fermi National Accelerator Laboratory, Batavia, IL (United States)
2014-09-15T23:59:59.000Z
Accelerating parameters of beam-driven wakefield acceleration in an extremely dense plasma column has been analyzed with the dynamic framed particle-in-cell plasma simulator, and compared with analytic calculations. In the model, a witness beam undergoes a TeV/m scale alternating potential gradient excited by a micro-bunched drive beam in a 10^{25} m^{-3} and 1.6 x 10^{28} m^{-3 }plasma column. The acceleration gradient, energy gain, and transformer ratio have been extensively studied in quasi-linear, linear-, and blowout-regimes. The simulation analysis indicated that in the beam-driven acceleration system a hollow plasma channel offers 20 % higher acceleration gradient by enlarging the channel radius (r) from 0.2 ?_{p} to 0.6 ?_{p} in a blowout regime. This paper suggests a feasibility of TeV/m scale acceleration with a hollow crystalline structure (e.g. nanotubes) of high electron plasma density.
Beam-driven acceleration in ultra-dense plasma media
Shin, Young-Min [Department of Physics, Northern Illinois University, Dekalb, Illinois 60115 (United States); Accelerator Physics Center (APC), Fermi National Accelerator Laboratory (FNAL), Batavia, Illinois 60510 (United States)
2014-09-15T23:59:59.000Z
Accelerating parameters of beam-driven wakefield acceleration in an extremely dense plasma column has been analyzed with the dynamic framed particle-in-cell plasma simulator, and compared with analytic calculations. In the model, a witness beam undergoes a TeV/m scale alternating potential gradient excited by a micro-bunched drive beam in a 10{sup 25?}m{sup ?3} and 1.6?×?10{sup 28?}m{sup ?3} plasma column. The acceleration gradient, energy gain, and transformer ratio have been extensively studied in quasi-linear, linear-, and blowout-regimes. The simulation analysis indicated that in the beam-driven acceleration system a hollow plasma channel offers ?20% higher acceleration gradient by enlarging the channel radius (r) from 0.2 ?{sub p} to 0.6 ?{sub p} in a blowout regime. This paper suggests a feasibility of TeV/m scale acceleration with a hollow crystalline structure (e.g., nanotubes) of high electron plasma density.
Linear and Nonlinear PT-symmetric Oligomers: A Dynamical Systems Analysis
M. Duanmu; K. Li; R. L. Horne; P. G. Kevrekidis; N. Whitaker
2012-10-15T23:59:59.000Z
In the present work we focus on the cases of two-site (dimer) and three-site (trimer) configurations, i.e. oligomers, respecting the parity-time (PT) symmetry, i.e., with a spatially odd gain-loss profile. We examine different types of solutions of such configurations with linear and nonlinear gain/loss profiles. Solutions beyond the linear PT-symmetry critical point as well as solutions with asymmetric linearization eigenvalues are found in both the nonlinear dimer and trimer. The latter feature is absent in linear PT-symmetric trimers, while both of them are absent in linear PT symmetric dimers. Furthermore, nonlinear gain/loss terms enable the existence of both symmetric and asymmetric solution profiles (and of bifurcations between them), while only symmetric solutions are present in the linear PT-symmetric dimers and trimers. The linear stability analysis around the obtained solutions is discussed and their dynamical evolution is explored by means of direct numerical simulations. Finally, a brief discussion is also given of recent progress in the context of PT-symmetric quadrimers.
Antsaklis, Panos
Linear State Feedback," Control Systems Technical Report #55, Dept. of Electrical and Computer," Control Systems Technical Report #55, Dept. of Electrical and Computer Engineering, University of Notre Feedback," Control Systems Technical Report #55, Dept. of Electrical and Computer Engineering, University
Development of a Rating System for a Comparative Accelerated Test Standard (Presentation)
Kurtz, S.
2013-06-01T23:59:59.000Z
This presentation discusses methods of developing and structuring a useful rating system and communicating the results.
Progress on laser plasma accelerators
Chen, P.
1986-04-01T23:59:59.000Z
Several laser plasma accelerator schemes are reviewed, with emphasis on the Plasma Beat Wave Accelerator (PBWA). Theory indicates that a very high acceleration gradient, of order 1 GeV/m, can exist in the plasma wave driven by the beating lasers. Experimental results obtained on the PBWA experiment at UCLA confirms this. Parameters related to the PBWA as an accelerator system are derived, among them issues concerning the efficiency and the laser power and energy requirements are discussed.
Advancing Large Scale Many-Body QMC Simulations on GPU accelerated Multicore Systems
California at Davis, University of
and superconductors. It treats these interactions exactly, but the solution of a system of N electrons must
Radiation from Accelerated Branes
Mohab Abou-Zeid; Miguel S. Costa
2000-01-29T23:59:59.000Z
The radiation emitted by accelerated fundamental strings and D-branes is studied within the linear approximation to the supergravity limit of string theory. We show that scalar, gauge field and gravitational radiation is generically emitted by such branes. In the case where an external scalar field accelerates the branes, we derive a Larmor-type formula for the emitted scalar radiation and study the angular distribution of the outgoing energy flux. The classical radii of the branes are calculated by means of the corresponding Thompson scattering cross sections. Within the linear approximation, the interaction of the external scalar field with the velocity fields of the branes gives a contribution to the observed gauge field and gravitational radiation.
Fiber Bragg Grating Sensors Based Monitoring System for Superconducting Accelerator Magnets
Chiuchiolo, A; Perez, J C; Bajas, H; Consales, M; Giordano, M; Breglio, G; Cusano, A
2014-01-01T23:59:59.000Z
New generation of accelerator magnets for high energy applications currently designed, manufactured and tested at the European Organization for Nuclear Research (CERN) require the implementation of precise cryogenic sensors with long-term robustness and reliability able to withstand cryogenic temperature and to monitor the mechanical stresses affecting the winding during all the stages of his service life, assembly, cool down and powering. Monitoring the mechanical behavior of the magnet from assembly to operation is a critical task which aims to assure the integrity of the magnet and to safely handle the coils made of new brittle material. This contribution deals with the first successful embedding of Fiber Bragg Grating sensors in a subscale Nb3Sn dipole magnet in order to monitor the strain developed in the coil during the cool down to 1.9 K, the powering up to 15.8 kA and the warm up, offering new perspectives for the development of a complementary sensing technology based on fiber optic sensors.
Science opportunities at high power accelerators like APT
Browne, J.C.
1996-12-31T23:59:59.000Z
This paper presents applications of high power RF proton linear accelerators to several fields. Radioisotope production is an area in which linacs have already provided new isotopes for use in medical and industrial applications. A new type of spallation neutron source, called a long-pulse spallation source (LPSS), is discussed for application to neutron scattering and to the production and use of ultra-cold neutrons (UCN). The concept of an accelerator-driven, transmutation of nuclear waste system, based on high power RF linac technology, is presented along with its impact on spent nuclear fuels.
OPERATING EXPERIENCE WITH A NEW ACCELERATOR CONTROL SYSTEM BASED UPON MICROPROCESSORS
Magyary, S.
2010-01-01T23:59:59.000Z
CONTROL SYSTEM BASED UPON MICROPROCESSORS* E S. Magyary, H.architecture of i t s microprocessor based control systemlarge number (~20) of microprocessor boards, each executiny
Dynamics of atom-field probability amplitudes in a coupled cavity system with Kerr non-linearity
Priyesh, K. V.; Thayyullathil, Ramesh Babu [Department of Physics, Cochin University of Science and Technology, Cochin (India)
2014-01-28T23:59:59.000Z
We have investigated the dynamics of two cavities coupled together via photon hopping, filled with Kerr non-linear medium and each containing a two level atom in it. The evolution of various atom (field) state probabilities of the coupled cavity system in two excitation sub space are obtained numerically. Detailed analysis has been done by taking different initial conditions of the system, with various coupling strengths and by varying the susceptibility of the medium. The role of susceptibility factor, on the dynamics atom field probability has been examined. In a coupled cavity system with strong photon hopping it is found that the susceptibility factor modifies the behaviour of probability amplitudes.
Cryogenic systems for the HEB accelerator of the Superconducting Super Collider
Abramovich, S.; Yuecel, A.
1994-07-01T23:59:59.000Z
This report discusses the following topics related to the Superconducting Super Collider: Cryogenic system -- general requirements; cryogenic system components; heat load budgets and refrigeration plant capacities; flow and thermal characteristics; process descriptions; cryogenic control instrumentation and value engineering trade-offs.
LASER-PLASMA-ACCELERATOR-BASED COLLIDERS C. B. Schroeder
Geddes, Cameron Guy Robinson
LASER-PLASMA-ACCELERATOR-BASED COLLIDERS C. B. Schroeder , E. Esarey, Cs. T´oth, C. G. R. Geddes-generation linear col- lider based on laser-plasma-accelerators are discussed, and a laser-plasma-accelerator gamma-gamma () collider is considered. An example of the parameters for a 0.5 TeV laser-plasma-accelerator collider
Rong, Yue; Tang, Xiaojun; Hua, Yingbo
2009-01-01T23:59:59.000Z
MIMO RELAY COMMUNICATION SYSTEMS [25] S. M. Kay,MIMO RELAY COMMUNICATION SYSTEMS Fig. 4. Example 3: BERMIMO Relay Communication Systems Yue Rong, Member, IEEE,
Linearity and Noise Improvement Techniques Employing Low Power in Analog and RF Circuits and Systems
Abdel Ghany, Ehab
2012-12-07T23:59:59.000Z
Trans. Circuits Syst. II, vol. 57, no. 12, pp. 921-925. 4 Cartesian feedback (CFB) [1, 2] is one of the methods to linearize an RF transmit- ter and enhance the spectral purity of nonlinear circuits. CFB is an analog solution that achieves high e...
Zero crossings, overshoot and initial undershoot in the step and impulse responses of linear systems
Damm, Tobias
1 Zero crossings, overshoot and initial undershoot in the step and impulse responses of linear-known. (i) The number of zero crossings of the step and impulse response is bounded from below by the number (counting multiplicities), then the step response exhibits initial undershoot, see [4]. Our goal
System Demonstration of Spiral: Generator for High-Performance Linear Transform Libraries
Franchetti, Franz
-specific language, program generation, rewriting, matrix algebra, automatic performance tuning, multithreading, SIMD been made towards this goal, in particular in two performance- critical domains: linear algebra] to generate code for small fixed size transform functions, called "codelets". However, all top-level recursive
Maximum Output Amplitude of Linear Systems for certain Input Constraints1
Sontag, Eduardo
of this input and calculates the maximum amplitude of the output. The solution of this problem is a necessary, Linear Sys- tems. 1 Introduction and Motivation Most practical control problems are dominated by hard bounds. Valves can only be operated between fully open and fully closed, pumps and compressors have
Muon Acceleration in Cosmic-ray Sources
Spencer R. Klein; Rune Mikkelsen; Julia K. Becker Tjus
2012-08-09T23:59:59.000Z
Many models of ultra-high energy cosmic-ray production involve acceleration in linear accelerators located in Gamma-Ray Bursts magnetars, or other sources. These source models require very high accelerating gradients, $10^{13}$ keV/cm, with the minimum gradient set by the length of the source. At gradients above 1.6 keV/cm, muons produced by hadronic interactions undergo significant acceleration before they decay. This acceleration hardens the neutrino energy spectrum and greatly increases the high-energy neutrino flux. We rule out many models of linear acceleration, setting strong constraints on plasma wakefield accelerators and on models for sources like Gamma Ray Bursts and magnetars.
Indirectly sensing accelerator beam currents for limiting maximum beam current magnitude
Bogaty, J.M.; Clifft, B.E.; Bollinger, L.M.
1995-08-08T23:59:59.000Z
A beam current limiter is disclosed for sensing and limiting the beam current in a particle accelerator, such as a cyclotron or linear accelerator, used in scientific research and medical treatment. A pair of independently operable capacitive electrodes sense the passage of charged particle bunches to develop an RF signal indicative of the beam current magnitude produced at the output of a bunched beam accelerator. The RF signal produced by each sensing electrode is converted to a variable DC voltage indicative of the beam current magnitude. The variable DC voltages thus developed are compared to each other to verify proper system function and are further compared to known references to detect beam currents in excess of pre-established limits. In the event of a system malfunction, or if the detected beam current exceeds pre-established limits, the beam current limiter automatically inhibits further accelerator operation. A high Q tank circuit associated with each sensing electrode provides a narrow system bandwidth to reduce noise and enhance dynamic range. System linearity is provided by injecting, into each sensing electrode, an RF signal that is offset from the bunching frequency by a pre-determined beat frequency to ensure that subsequent rectifying diodes operate in a linear response region. The system thus provides a large dynamic range in combination with good linearity. 6 figs.
Indirectly sensing accelerator beam currents for limiting maximum beam current magnitude
Bogaty, John M. (Lombard, IL); Clifft, Benny E. (Park Forest, IL); Bollinger, Lowell M. (Downers Grove, IL)
1995-01-01T23:59:59.000Z
A beam current limiter for sensing and limiting the beam current in a particle accelerator, such as a cyclotron or linear accelerator, used in scientific research and medical treatment. A pair of independently operable capacitive electrodes sense the passage of charged particle bunches to develop an RF signal indicative of the beam current magnitude produced at the output of a bunched beam accelerator. The RF signal produced by each sensing electrode is converted to a variable DC voltage indicative of the beam current magnitude. The variable DC voltages thus developed are compared to each other to verify proper system function and are further compared to known references to detect beam currents in excess of pre-established limits. In the event of a system malfunction, or if the detected beam current exceeds pre-established limits, the beam current limiter automatically inhibits further accelerator operation. A high Q tank circuit associated with each sensing electrode provides a narrow system bandwidth to reduce noise and enhance dynamic range. System linearity is provided by injecting, into each sensing electrode, an RF signal that is offset from the bunching frequency by a pre-determined beat frequency to ensure that subsequent rectifying diodes operate in a linear response region. The system thus provides a large dynamic range in combination with good linearity.
Shih, Ting-Chih
2009-01-01T23:59:59.000Z
Raytheon produces a diverse range of defense products using a wide range of business systems and tools that are not currently integrated. To achieve the corporate vision of "one company", in 2005, Raytheon began to deploy ...
Shinozuka, Masanobu
sensor network 1. INTRODUCTION Urban water distribution systems, particularly underground pipeline networks, can be damaged due to earthquake, pipe corrosion, severely cold weather, heavy traffic load include corrosion and aging, excessive surface traffic load- ing, soil failure, etc. For identifying
An RF Waveguide Distribution System for the ILC Test Accelerator at Fermilab's NML
Nantista, Christopher; Adolphsen, Chris; Bowden, Gordon; Swent, Richard; McKee, Bobby; /SLAC
2007-06-27T23:59:59.000Z
An ILC R&D facility is being constructed in the NML building at Fermilab which, in addition to an injector and beam dump with spectrometer, will contain up to three cryomodules of ILC-type superconducting 9-cell cavities. This linac will be powered by a single klystron. As part of SLAC's contribution to this project, we will provide a distribution network in WR650 waveguide to the various cavity couplers. In addition to commercial waveguide components and circulators and loads, this system will include adjustable tap-offs, and customized hybrids. In one configuration, the circulators will be removed to test pair-wise cancellation of cavity reflections through hybrids. The system will be pressurized with nitrogen to 3 bar absolute to avoid the need for SF{sub 6}. The full distribution system for the first cryomodule will be delivered and installed later this year. We describe the design of the system and completed RF testing.
Pyeon, C. H.; Yagi, T.; Lim, J. Y.; Misawa, T. [Nuclear Science Engineering Div., Research Reactor Inst., Kyoto Univ., Asashiro-nishi, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan)
2012-07-01T23:59:59.000Z
The experimental study on the thorium-loaded accelerator-driven system (ADS) is conducted in the Kyoto Univ. Critical Assembly (KUCA). The experiments are carried out in both the critical and subcritical states for attaining the reaction rates of the thorium capture and fission reactions. In the critical system, the thorium plate irradiation experiment is carried out for the thorium capture and fission reactions. From the results of the measurements, the thorium fission reactions are obtained apparently in the critical system, and the C/E values of reaction rates show the accuracy of relative difference of about 30%. In the ADS experiments with 14 MeV neutrons and 100 MeV protons, the subcritical experiments are carried out in the thorium-loaded cores to obtain the capture reaction rates through the measurements of {sup 115}In(n, {gamma}){sup 116m}In reactions. The results of the experiments reveal the difference between the reaction rate distributions for the change in not only the neutron spectrum but also the external neutron source. The comparison between the measured and calculated reaction rate distributions demonstrates a discrepancy of the accuracy of reaction rate analyses of thorium capture reactions through the thorium-loaded ADS experiments with 14 MeV neutrons. Hereafter, kinetic experiments are planned to be carried out to deduce the delayed neutron decay constants and subcriticality using the pulsed neutron method. (authors)
A polynomial projection algorithm for linear programming
2013-05-03T23:59:59.000Z
We propose a polynomial algorithm for linear programming. The algorithm represents a linear optimization or decision problem in the form of a system of linear ...
Abdel-Rehim, A. M.; Stathopoulos, Andreas; Orginos, Kostas
2014-08-01T23:59:59.000Z
The technique that was used to build the EigCG algorithm for sparse symmetric linear systems is extended to the nonsymmetric case using the BiCG algorithm. We show that, similarly to the symmetric case, we can build an algorithm that is capable of computing a few smallest magnitude eigenvalues and their corresponding left and right eigenvectors of a nonsymmetric matrix using only a small window of the BiCG residuals while simultaneously solving a linear system with that matrix. For a system with multiple right-hand sides, we give an algorithm that computes incrementally more eigenvalues while solving the first few systems and then uses the computed eigenvectors to deflate BiCGStab for the remaining systems. Our experiments on various test problems, including Lattice QCD, show the remarkable ability of EigBiCG to compute spectral approximations with accuracy comparable to that of the unrestarted, nonsymmetric Lanczos. Furthermore, our incremental EigBiCG followed by appropriately restarted and deflated BiCGStab provides a competitive method for systems with multiple right-hand sides.
Broader source: Energy.gov [DOE]
Presentation given by Argonne National Laboratory at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about accelerating the...
Broader source: Energy.gov [DOE]
Presentation given by Argonne National Laboratory at 2015 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about accelerate the...
Stephens, Jennifer Anne
2006-04-12T23:59:59.000Z
on the evaluation procedures of whole-school reform organizations. Because the ultimate goal is to improve school performance, it should also be a goal of each whole-school reform organization to design a comprehensive data collection system to evaluate each school...
The International Linear Collider
Marco Battaglia
2007-05-28T23:59:59.000Z
The International Linear Collider (ILC) is the next large scale project in accelerator particle physics. Colliding electrons with positrons at energies from 0.3 TeV up to about 1 TeV, the ILC is expected to provide the accuracy needed to complement the LHC data and extend the sensitivity to new phenomena at the high energy frontier and answer some of the fundamental questions in particle physics and in its relation to Cosmology. This paper reviews some highlights of the ILC physics program and some of the major challenges for the accelerator and detector design.
International linear collider reference design report
Aarons, G.
2008-01-01T23:59:59.000Z
those of other modern accelerator control systems, includingmodern telecom switches and computer servers, but has not been a requirement of present accelerator control systems.system using digital feedback control. Digital Technologies The key technologies to be used are modern
Widely linear equalization for MIMO and SISO communications systems using filter banks
Pun, Ka Shun Carson
2007-01-01T23:59:59.000Z
Figure 4.3: The communications system employing a complex3.4: The overall communications system (as a virtual MIMOFigure 3.1: The communications system with M t -transmitting
Structural changes in quasi- 1D many-electron systems: from linear to zig-zag and beyond
Ballone, R Cortes-Huerto M Paternostro P
2010-01-01T23:59:59.000Z
Many-electron systems confined to a quasi-1D geometry by a cylindrical distribution of positive charge have been investigated by density functional computations in the unrestricted local spin density approximation. Our investigations have been focused on the low density regime, in which electrons are localised. The results reveal a wide variety of different charge and spin configurations, including linear and zig-zag chains, single and double-strand helices, and twisted chains of dimers. The spin-spin coupling turns from weakly anti-ferromagnetic at relatively high density, to weakly ferromagnetic at the lowest densities considered in our computations. The stability of linear chains of localised charge has been investigated by analysing the radial dependence of the self-consistent potential and by computing the dispersion relation of low-energy harmonic excitations.
Structural changes in quasi- 1D many-electron systems: from linear to zig-zag and beyond
R. Cortes-Huerto M. Paternostro P. Ballone
2010-05-24T23:59:59.000Z
Many-electron systems confined to a quasi-1D geometry by a cylindrical distribution of positive charge have been investigated by density functional computations in the unrestricted local spin density approximation. Our investigations have been focused on the low density regime, in which electrons are localised. The results reveal a wide variety of different charge and spin configurations, including linear and zig-zag chains, single and double-strand helices, and twisted chains of dimers. The spin-spin coupling turns from weakly anti-ferromagnetic at relatively high density, to weakly ferromagnetic at the lowest densities considered in our computations. The stability of linear chains of localised charge has been investigated by analysing the radial dependence of the self-consistent potential and by computing the dispersion relation of low-energy harmonic excitations.
International Workshop on Linear Colliders 2010
None
2011-10-06T23:59:59.000Z
IWLC2010 International Workshop on Linear Colliders 2010ECFA-CLIC-ILC joint meeting: Monday 18 October - Friday 22 October 2010Venue: CERN and CICG (International Conference Centre Geneva, Switzerland) This year, the International Workshop on Linear Colliders organized by the European Committee for Future Accelerators (ECFA) will study the physics, detectors and accelerator complex of a linear collider covering both CLIC and ILC options.Contact Workshop Secretariat IWLC2010 is hosted by CERN
On the linear operation of cloned dynamical systems and its Lyapunov exponents
Pengfei Wang
2014-03-16T23:59:59.000Z
The cloned dynamical system theory is introduced and the Lyapunov exponents of this system are qualitatively proven to be same as the original dynamical system. This property indicates that these two systems have the same error propagation speed in the phase space, and thus we can interpret the phenomenon as why the ensemble mean method sometimes is not effective.
Novel MIMO Linear Zero Dynamic Controller for the Grid-connected Photovoltaic System with
Pota, Himanshu Roy
connected PV system also has its own draw- backs, the conversion efficiency of the inverter is low under low (PV) system. The relative degree is investigated through the concept of Lie derivative to execute the LZDC for three phase grid connected PV system. To implement the control theory, system stability
Accelerators and the Accelerator Community
Malamud, Ernest
2009-01-01T23:59:59.000Z
became the APS Division of the Physics of Beams. If oneorganizes accelerator physics sessions at APS meetings, and,creating the APS topical group on beam physics, which later
Jr, Peter Chien; Rosenman, Karla; Cheung, Wang; Wang, Nadia; Sanchez, Miguel
2009-01-01T23:59:59.000Z
type 1/type 2 mosaic of psoriasis? Dermatology 2006; 212:Magalhaes RF, et al. Linear psoriasis in Brazilian childrensuffering from linear psoriasis along lines of Blaschko. Br
Muon acceleration in cosmic-ray sources
Klein, Spencer R.; Mikkelsen, Rune E. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Becker Tjus, Julia [Fakultät für Physik and Astronomie, Theoretische Physik I, Ruhr-Universität Bochum, D-44780 Bochum (Germany)
2013-12-20T23:59:59.000Z
Many models of ultra-high energy cosmic-ray production involve acceleration in linear accelerators located in gamma-ray bursts, magnetars, or other sources. These transient sources have short lifetimes, which necessitate very high accelerating gradients, up to 10{sup 13} keV cm{sup –1}. At gradients above 1.6 keV cm{sup –1}, muons produced by hadronic interactions undergo significant acceleration before they decay. This muon acceleration hardens the neutrino energy spectrum and greatly increases the high-energy neutrino flux. Using the IceCube high-energy diffuse neutrino flux limits, we set two-dimensional limits on the source opacity and matter density, as a function of accelerating gradient. These limits put strong constraints on different models of particle acceleration, particularly those based on plasma wake-field acceleration, and limit models for sources like gamma-ray bursts and magnetars.
Fowler, John Welsh
1986-01-01T23:59:59.000Z
AND CONCLUSIONS REFERENCES APPENDICES APPENDIX A ? USER' S MANUAL APPENDIX B ? CODE CHANGES NECESSARY TO PREVENT CYCLING IN THE K SHORTEST PATH PROBLEM VITA 90 92 94 95 110 112 LIST OF TABLES Table DISTANCE MATRIX Page 15 INPUT DATA FOR PLANNING... variety of problems and situations. Network analysis techniques have been used to model transportation systems, communication systems, distribution systems, river systems, precedence ordering of events, computer systems, etc. Phillips and Garcia [1981...
IPAC15 Jefferson Lab - International Particle Accelerator Conference...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
D07 High Intensity Circular Machines - Space Charge, Halos D08 High Intensity in Linear Accelerators - Space Charge, Halos D09 Emittance manipulation, Bunch Compression...
Tranceiver Design using Linear Precoding in a Multiuser MIMO System with Limited
Adve, Raviraj
(MU) multiple input single output (MISO) and multiple input multiple output (MIMO) Page 1 of 23 IET increase system reliability as well as the spectral efficiency of multiuser systems. However, limitations caused by interference and channel fading remain a concern in MU MISO and MU MIMO systems. These can
Multiple-Input Multiple-Output (MIMO) Linear Systems Extreme Inputs/Outputs
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Smallwood, David O.
2007-01-01T23:59:59.000Z
A linear structure is excited at multiple points with a stationary normal random process. The response of the structure is measured at multiple outputs. If the autospectral densities of the inputs are specified, the phase relationships between the inputs are derived that will minimize or maximize the trace of the autospectral density matrix of the outputs. If the autospectral densities of the outputs are specified, the phase relationships between the outputs that will minimize or maximize the trace of the input autospectral density matrix are derived. It is shown that other phase relationships and ordinary coherence less than one willmore »result in a trace intermediate between these extremes. Least favorable response and some classes of critical response are special cases of the development. It is shown that the derivation for stationary random waveforms can also be applied to nonstationary random, transients, and deterministic waveforms.« less
Fourier Accelerated Conjugate Gradient Lattice Gauge Fixing
R. J. Hudspith
2014-05-22T23:59:59.000Z
We provide details of the first implementation of a non-linear conjugate gradient method for Landau and Coulomb gauge fixing with Fourier acceleration. We find clear improvement over the Fourier accelerated steepest descent method, with the average time taken for the algorithm to converge to a fixed, high accuracy, being reduced by a factor of 2 to 4.
Milan Batista; Abdel Rahman A. Ibrahim Karawia
2008-07-24T23:59:59.000Z
The article presents the theoretical background of the algorithms for solving cyclic block tridiagonal and cyclic block penta-diagonal systems of linear algebraic equations present in ref [1] and [2]. The theory is based on the Woodbury formula.
Gajic, Zoran
students interested in linear dynamic systems and signals---especially biomedical, aerospace, mechanical processing courses. In addition, many problems in wireless communications, networking, signal processing senior level courses in wireless communications, networking, photonics, and signal processing, some
Gajic, Zoran
students interested in linear dynamic systems and signals--especially biomedical, aerospace, mechanical processing courses. In addition, many problems in wireless communications, networking, signal processing senior level courses in wireless communications, networking, photonics, and signal processing, some
Widely linear equalization for MIMO and SISO communications systems using filter banks
Pun, Ka Shun Carson
2007-01-01T23:59:59.000Z
Selective MISO Channel . . . . . . . . . . . . . . . .input-single- output (MISO) channel is not fully addressed.system in a frequency selective MISO channel and the WLE
The Laboratory SLAC National Accelerator Laboratory is home to a two-mile
Wechsler, Risa H.
-program laboratory for photon science, astrophysics, and accelerator and particle physics research. Six scientists promises to be just as extraordinary. #12;Accelerator Physics Particle accelerators are the working engines#12;The Laboratory SLAC National Accelerator Laboratory is home to a two-mile linear accelerator
Wang, Zhehui (Los Alamos, NM); Barnes, Cris W. (Santa Fe, NM)
2002-01-01T23:59:59.000Z
There has been invented an apparatus for acceleration of a plasma having coaxially positioned, constant diameter, cylindrical electrodes which are modified to converge (for a positive polarity inner electrode and a negatively charged outer electrode) at the plasma output end of the annulus between the electrodes to achieve improved particle flux per unit of power.
Paris-Sud XI, Université de
Sensing cum Actuating Linear Motor Ali Karimi Varkani Tarbiat Modares University Tehran, Iran ali of an electric machine (a linear motor) without using conventional sensors. Tested is a back-drivable linear motor stage which uses the linear motor electric machine as simultaneous sensor cum actuator
Irrigation System Scientists: B. Wherley and A. Chandra - Texas AgriLife Research- Dallas, and J. Heitholt gradient irrigation system (LGIS) project were to 1) quantify the extent of water stress that different the implications of deficit irrigation practices on reflective heat load generation, and 3) determine how cultural
LINEAR SYSTEMS WITH SIGN-OBSERVATIONS RENEE KOPLON AND EDUARDO D. SONTAG
Sontag, Eduardo
relatively simple systems. However, for large-scale problems, controllers resulting from the application, various types of switching controllers, and humans Âor, more re- cently, expert systems,Â in supervisory the interplay of modern control theory with automata theory and other techniques from computer science
Sontag, Eduardo
- cations in control of mechanical systems, process control, au- tomotive industry, power systems, aircraft variations and exterior disturbances are considered. The problem of synthesis of switching control laws that orchestrates switching between these subsystems. Properties of this type of model have been studied
Linear-optical simulation of the cooling of a cluster-state Hamiltonian system
G. H. Aguilar; T. Kolb; D. Cavalcanti; L. Aolita; R. Chaves; S. P. Walborn; P. H. Souto Ribeiro
2014-03-26T23:59:59.000Z
A measurement-based quantum computer could consist of a local-gapped Hamiltonian system, whose thermal states --at sufficiently low temperature-- are universal resources for the computation. Initialization of the computer would correspond to cooling the system. We perform an experimental quantum simulation of such cooling process with entangled photons. We prepare three-qubit thermal cluster states exploiting the equivalence between local dephasing and thermalisation for these states. This allows us to tune the system's temperature by changing the dephasing strength. We monitor the entanglement as the system cools down and observe the transitions from separability to bound entanglement, and then to free entanglement. We also analyze the performance of the system for measurement-based single-qubit state preparation. These studies constitute a basic characterisation of experimental cluster-state computation under imperfect conditions.
Advances in Ion Accelerators Boost Argonne's ATLAS User Facility...
Office of Science (SC) Website
as well as accelerator driven systems for nuclear waste transmutation or power generation, high-current accelerator-based isotope production facilities, and compact...
Test Facility Daniil Stolyarov, Accelerator Test Facility User...
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Development of the Solid-State Laser System for the Accelerator Test Facility Daniil Stolyarov, Accelerator Test Facility User's Meeting April 3, 2009 Outline Motivation for...
Antsaklis, Panos
Optimal Controller for Disturbance Attenuation in Linear Hybrid Systems," Proc. of the 16th IFAC World Hybrid Optimal Controller for Disturbance Attenuation in Linear Hybrid Systems," Proc. of the 16th IFAC, "Explicit Hybrid Optimal Controller for Disturbance Attenuation in Linear Hybrid Systems," Proc. of the 16th
Thomas Precession by Uniform Acceleration
Pardy, Miroslav
2015-01-01T23:59:59.000Z
We determine the nonlinear transformations between coordinate systems which are mutually in a constant symmetrical accelerated motion. The maximal acceleration limit follows from the kinematical origin and it is an analogue of the maximal velocity in special relativity. We derive the dependence of mass, length, time, Doppler effect, Cherenkov effect and transition radiation angle on acceleration as an analogue phenomena in special theory of relativity. The last application of our method is the Thomas precession by uniform acceleration with the possible role in the modern physics and cosmology. The comparison of derived results with other relativistic methods is necessary.
Thomas Precession by Uniform Acceleration
Miroslav Pardy
2014-12-09T23:59:59.000Z
We determine the nonlinear transformations between coordinate systems which are mutually in a constant symmetrical accelerated motion. The maximal acceleration limit follows from the kinematical origin and it is an analogue of the maximal velocity in special relativity. We derive the dependence of mass, length, time, Doppler effect, Cherenkov effect and transition radiation angle on acceleration as an analogue phenomena in special theory of relativity. The last application of our method is the Thomas precession by uniform acceleration with the possible role in the modern physics and cosmology. The comparison of derived results with other relativistic methods is necessary.
Spin Transport and Polarimetry in the Beam Delivery System of the International Linear Collider
Beckmann, Moritz; Vauth, Annika; Vormwald, Benedikt
2014-01-01T23:59:59.000Z
Polarised electron and positron beams are key ingredients to the physics programme of future linear colliders. Due to the chiral nature of weak interactions in the Standard Model - and possibly beyond - the knowledge of the luminosity-weighted average beam polarisation at the $e^+e^-$ interaction point is of similar importance as the knowledge of the luminosity and has to be controlled to permille-level precision in order to fully exploit the physics potential. The current concept to reach this challenging goal combines measurements from Laser-Compton polarimeters before and after the interaction point with measurements at the interaction point. A key element for this enterprise is the understanding of spin-transport effects between the polarimeters and the interaction point as well as collision effects. We show that without collisions, the polarimeters can be cross-calibrated to 0.1 %, and we discuss in detail the impact of collision effects and beam parameters on the polarisation value relevant for the inte...
A flexible uncertainty quantification method for linearly coupled multi-physics systems
Chen, Xiao, E-mail: chen73@llnl.gov; Ng, Brenda; Sun, Yunwei; Tong, Charles, E-mail: tong10@llnl.gov
2013-09-01T23:59:59.000Z
Highlights: •We propose a “modularly hybrid” UQ methodology suitable for independent development of module-based multi-physics simulation. •Our algorithmic framework allows for each module to have its own UQ method (either intrusive or non-intrusive). •Information from each module is combined systematically to propagate “global uncertainty”. •Our proposed approach can allow for easy swapping of new methods for any modules without the need to address incompatibilities. •We demonstrate the proposed framework on a practical application involving a multi-species reactive transport model. -- Abstract: This paper presents a novel approach to building an integrated uncertainty quantification (UQ) methodology suitable for modern-day component-based approach for multi-physics simulation development. Our “hybrid” UQ methodology supports independent development of the most suitable UQ method, intrusive or non-intrusive, for each physics module by providing an algorithmic framework to couple these “stochastic” modules for propagating “global” uncertainties. We address algorithmic and computational issues associated with the construction of this hybrid framework. We demonstrate the utility of such a framework on a practical application involving a linearly coupled multi-species reactive transport model.
Linear Processing for the Downlink in Multiuser MIMO Systems with Multiple Data Streams
Adve, Raviraj
the reliability and data rate of a transmission. More recently, researchers have investigated using downlink problem with individual SINR constraints in a multiple-input single-output (MISO) system, i
On the synthesis of switched output feedback controllers for linear, time-invariant systems
Santarelli, Keith R. (Keith Robert), 1977-
2007-01-01T23:59:59.000Z
The theory of switching systems has seen many advances in the past decade. Its beginnings were founded primarily due to the physical limitations in devices to implement control such as relays, but today there exists a ...
A Single Differential Equation for First-Excursion Time in a Class of Linear Systems
Greytak, Matthew B.
First-excursion times have been developed extensively in the literature for oscillators; one major application is structural dynamics of buildings. Using the fact that most closed-loop systems operate with a moderate to ...
Li, Bin
2012-11-29T23:59:59.000Z
Most designs for wave energy converters include a hydraulic (or pneumatic) interface between the wave device and the generator to smooth electricity production, but a direct drive power take-off system is a possible way ...
Prediction-based stabilization of linear systems subject to input-dependent input delay of
Boyer, Edmond
engine [17] and exhaust line [13], heat collector plant [32], blending in liquid or solid networks [12 of system fitting inside this framework is the one of the exhaust Fuel/Air Ratio (FAR) for Gasoline engines
Ackermann, Mark R. (Albuquerque, NM); Diels, Jean-Claude M. (Albuquerque, NM)
2007-06-26T23:59:59.000Z
An optical system comprising a concave primary mirror reflects light through an intermediate focus to a secondary mirror. The secondary mirror re-focuses the image to a final image plane. Optical limiter material is placed near the intermediate focus to optically limit the intensity of light so that downstream components of the optical system are protected from intense optical transients. Additional lenses before and/or after the intermediate focus correct optical aberrations.
Gajic, Zoran
responses of a higher-order linear discrete- time system using MATLAB. We study system impulse, step , and find the impulse response of the reduced order system for k=0:1:40. Part 3. Find the step response using the MATLAB function dstep. Plot the step response k=0:1:14 and k=0:1:40. Comment
Model-independent particle accelerator tuning
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Scheinker, Alexander; Pang, Xiaoying; Rybarcyk, Larry
2013-10-01T23:59:59.000Z
We present a new model-independent dynamic feedback technique, rotation rate tuning, for automatically and simultaneously tuning coupled components of uncertain, complex systems. The main advantages of the method are: 1) It has the ability to handle unknown, time-varying systems, 2) It gives known bounds on parameter update rates, 3) We give an analytic proof of its convergence and its stability, and 4) It has a simple digital implementation through a control system such as the Experimental Physics and Industrial Control System (EPICS). Because this technique is model independent it may be useful as a real-time, in-hardware, feedback-based optimization scheme formore »uncertain and time-varying systems. In particular, it is robust enough to handle uncertainty due to coupling, thermal cycling, misalignments, and manufacturing imperfections. As a result, it may be used as a fine-tuning supplement for existing accelerator tuning/control schemes. We present multi-particle simulation results demonstrating the scheme’s ability to simultaneously adaptively adjust the set points of twenty two quadrupole magnets and two RF buncher cavities in the Los Alamos Neutron Science Center (LANSCE) Linear Accelerator’s transport region, while the beam properties and RF phase shift are continuously varying. The tuning is based only on beam current readings, without knowledge of particle dynamics. We also present an outline of how to implement this general scheme in software for optimization, and in hardware for feedback-based control/tuning, for a wide range of systems.« less
THE CRYOGENIC SYSTEM OF TESLA S. Wolff, DESY, Notkestr. 85, 22607 Hamburg, Germany
THE CRYOGENIC SYSTEM OF TESLA S. Wolff, DESY, Notkestr. 85, 22607 Hamburg, Germany for the TESLA collaboration Abstract TESLA, a 33 km long 500 GeV centre-of-mass energy superconducting linear collider The 33 km long e+ e- linear collider TESLA (Tera eV Energy Superconductiong Linear Accelerator) with 500
BERG,S.J.
2003-11-18T23:59:59.000Z
One of the major motivations driving recent interest in FFAGs is their use for the cost-effective acceleration of muons. This paper summarizes the progress in this area that was achieved leading up to and at the FFAG workshop at KEK from July 7-12, 2003. Much of the relevant background and references are also given here, to give a context to the progress we have made.
Testing a combined vibration and acceleration environment.
Jepsen, Richard Alan; Romero, Edward F.
2005-01-01T23:59:59.000Z
Sandia National Laboratories has previously tested a capability to impose a 7.5 g-rms (30 g peak) radial vibration load up to 2 kHz on a 25 lb object with superimposed 50 g acceleration at its centrifuge facility. This was accomplished by attaching a 3,000 lb Unholtz-Dickie mechanical shaker at the end of the centrifuge arm to create a 'Vibrafuge'. However, the combination of non-radial vibration directions, and linear accelerations higher than 50g's are currently not possible because of the load capabilities of the shaker and the stresses on the internal shaker components due to the combined centrifuge acceleration. Therefore, a new technique using amplified piezo-electric actuators has been developed to surpass the limitations of the mechanical shaker system. They are lightweight, modular and would overcome several limitations presented by the current shaker. They are 'scalable', that is, adding more piezo-electric units in parallel or in series can support larger-weight test articles or displacement/frequency regimes. In addition, the units could be mounted on the centrifuge arm in various configurations to provide a variety of input directions. The design along with test results will be presented to demonstrate the capabilities and limitations of the new piezo-electric Vibrafuge.
A Non-linear Dynamical Systems' Proof of Kraft-McMillan Inequality and its Converse
Nithin Nagaraj
2007-10-31T23:59:59.000Z
In this short paper, we shall provide a dynamical systems' proof of the famous Kraft-McMillan inequality and its converse. Kraft-McMillan inequality is a basic result in information theory which gives a necessary and sufficient condition for the lengths of the codewords of a code to be uniquely decodable.
Some Useful Matlab and Control Systems Toolbox Functions Creating and converting linear models
Abate, Alessandro
). step - Step response. impulse - Impulse response. lsim - Response to arbitrary inputs. bode - Bode-zero map. damp - Natural frequency and damping of system poles. ltiview - Response analysis GUI (LTI Viewer diagrams of the frequency response. ctrb - Controllability matrix (for ss models). obsv - Observability
Larsen, R.S.
1985-09-01T23:59:59.000Z
The SLD Detector will contain five major electronics subsystems: Vertex, Drift, Liquid Argon Calorimeter, Cerenkov Ring Imaging, and Warm Iron Calorimeter. To implement the approximately 170,000 channels of electronics, extensive miniaturization and heavy use of multiplexing techniques are required. Design criteria for each subsystem, overall system architecture, and the R and D program are described.
Approximation and inversion of a complex meteorological system via local linear filters
Schoenberg, Frederic Paik (Rick)
been the site of some of the nation's most severe air pollution (Lu et al., 1997b). In order to model to a complex mul- tivariate dynamic model for Southern California air quality is given and the method is shown, simulate, and predict levels of ozone and other pollutants, a multivariate dynamic modeling system called
Tube-based distributed control of linear constrained systems Stefano Riverso
Ferrari-Trecate, Giancarlo
to coupling. Lower controllers generate planned trajectories using Model Predictive Control (MPC) independently of the other subsystems. The proposed control scheme is arguably easier to design and apply than Control; Large-scale Systems; Robustness; Model Predictive Control; Decentralized Control. The research
A Linear Framework for Time-Scale Separation in Nonlinear Biochemical Systems
Gunawardena, Jeremy
permits unrestricted use, distribution, and reproduction in any medium, provided the original author combinatorial construction of vast numbers of molecular states, [2]. How such complexity evolves and how system and its environment adjust on slower time-scales to the steady-state of the sub
Becker, Jörg D
2015-01-01T23:59:59.000Z
In many European countries the growth of the real GDP per capita has been linear since 1950. An explanation for this linearity is still missing. We propose that in artificial intelligence we may find models for a linear growth of performance. We also discuss possible consequences of the fact that in systems with linear growth the percentage growth goes to zero.
NONE
1995-04-01T23:59:59.000Z
This Environmental Assessment (EA) analyzes the potential environmental impacts that would be expected to occur if the Department of Energy (DOE) were to construct and operate a small research and development laboratory building at Technical Area (TA) 53 at the Los Alamos National Laboratory (LANL), Los Alamos, New Mexico. DOE proposes to construct a small building to be called the Low Energy Accelerator Laboratory (LEAL), at a previously cleared, bladed, and leveled quarter-acre site next to other facilities housing linear accelerator research activities at TA-53. Operations proposed for LEAL would consist of bench-scale research, development, and testing of the initial section of linear particle accelerators. This initial section consists of various components that are collectively called an injector system. The anticipated life span of the proposed development program would be about 15 years.
Cox, James V.; Candelaria, Sam A.; Dugger, Michael Thomas; Duesterhaus, Michelle Ann; Tanner, Danelle Mary; Timpe, Shannon J.; Ohlhausen, James Anthony; Skousen, Troy J.; Jenkins, Mark W.; Jokiel, Bernhard, Jr.; Walraven, Jeremy Allen; Parson, Ted Blair
2006-06-01T23:59:59.000Z
Qualification of microsystems for weapon applications is critically dependent on our ability to build confidence in their performance, by predicting the evolution of their behavior over time in the stockpile. The objective of this work was to accelerate aging mechanisms operative in surface micromachined silicon microelectromechanical systems (MEMS) with contacting surfaces that are stored for many years prior to use, to determine the effects of aging on reliability, and relate those effects to changes in the behavior of interfaces. Hence the main focus was on 'dormant' storage effects on the reliability of devices having mechanical contacts, the first time they must move. A large number ({approx}1000) of modules containing prototype devices and diagnostic structures were packaged using the best available processes for simple electromechanical devices. The packaging processes evolved during the project to better protect surfaces from exposure to contaminants and water vapor. Packages were subjected to accelerated aging and stress tests to explore dormancy and operational environment effects on reliability and performance. Functional tests and quantitative measurements of adhesion and friction demonstrated that the main failure mechanism during dormant storage is change in adhesion and friction, precipitated by loss of the fluorinated monolayer applied after fabrication. The data indicate that damage to the monolayer can occur at water vapor concentrations as low as 500 ppm inside the package. The most common type of failure was attributed to surfaces that were in direct contact during aging. The application of quantitative methods for monolayer lubricant analysis showed that even though the coverage of vapor-deposited monolayers is generally very uniform, even on hidden surfaces, locations of intimate contact can be significantly depleted in initial concentration of lubricating molecules. These areas represent defects in the film prone to adsorption of water or contaminants that can cause movable structures to adhere. These analysis methods also indicated significant variability in the coverage of lubricating molecules from one coating process to another, even for identical processing conditions. The variability was due to residual molecules left in the deposition chamber after incomplete cleaning. The coating process was modified to result in improved uniformity and total coverage. Still, a direct correlation was found between the resulting static friction behavior of MEMS interfaces, and the absolute monolayer coverage. While experimental results indicated that many devices would fail to start after aging, the modeling approach used here predicted that all the devices should start. Adhesion modeling based upon values of adhesion energy from cantilever beams is therefore inadequate. Material deposition that bridged gaps was observed in some devices, and potentially inhibits start-up more than the adhesion model indicates. Advances were made in our ability to model MEMS devices, but additional combined experimental-modeling studies will be needed to advance the work to a point of providing predictive capability. The methodology developed here should prove useful in future assessments of device aging, however. Namely, it consisted of measuring interface properties, determining how they change with time, developing a model of device behavior incorporating interface behavior, and then using the age-aware interface behavior model to predict device function.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
in accelerator and beam physics. Some of the topics in Advanced Accelerator R&D are laser acceleration of electrons, wake field acceleration, novel high power rf sources, new...