WorldWideScience

Sample records for bistable latching solenoid

  1. Bistable (latching) solenoid actuated propellant isolation valve

    Science.gov (United States)

    Wichmann, H.; Deboi, H. H.

    1979-01-01

    The design, fabrication, assembly and test of a development configuration bistable (latching) solenoid actuated propellant isolation valve suitable for the control hydrazine and liquid fluorine to an 800 pound thrust rocket engine is described. The valve features a balanced poppet, utilizing metal bellows, a hard poppet/seat interface and a flexure support system for the internal moving components. This support system eliminates sliding surfaces, thereby rendering the valve free of self generated particles.

  2. Latching device

    Science.gov (United States)

    Ulrich, G. W. (Inventor)

    1975-01-01

    A latching device is suited for use in establishing a substantially motionless connection between a stationary receiver and a movable latching mechanism. The latching mechanism includes a pivotally supported restraining hook continuously urged into a capturing relationship with the receiver, characterized by a spring-biased pawl having a plurality of aligned teeth. The teeth are seated in the surface of the throat of the hook and positionable into restraining engagement with a rigid restraining shoulder projected from the receiver.

  3. Rotary mechanical latch

    Science.gov (United States)

    Spletzer, Barry L.; Martinez, Michael A.; Marron, Lisa C.

    2012-11-13

    A rotary mechanical latch for positive latching and unlatching of a rotary device with a latchable rotating assembly having a latching gear that can be driven to latched and unlatched states by a drive mechanism such as an electric motor. A cam arm affixed to the latching gear interfaces with leading and trailing latch cams affixed to a flange within the drive mechanism. The interaction of the cam arm with leading and trailing latch cams prevents rotation of the rotating assembly by external forces such as those due to vibration or tampering.

  4. Set–Reset latch logical operation induced by colored noise

    International Nuclear Information System (INIS)

    Wang, Nan; Song, Aiguo

    2014-01-01

    We examine the possibility of obtaining Set–Reset latch logical operation in a symmetric bistable system subjected to OU noise. Three major results are presented. First, we prove the Set–Reset latch logical operation can be obtained driven by OU noise. Second, while increasing the correlation time, the optimal noise band shifts to higher level and becomes wider. Meanwhile, peak performance degrades from 100% accuracy, but the system can still perform reliable logical operation. Third, at fixed noise intensity, the success probability evolves non-monotonically as correlation time increases. The study might provide development of the new paradigm of memory device.

  5. Bistable microelectromechanical actuator

    Science.gov (United States)

    Fleming, James G.

    1999-01-01

    A bistable microelectromechanical (MEM) actuator is formed on a substrate and includes a stressed membrane of generally rectangular shape that upon release assumes a curvilinear cross-sectional shape due to attachment at a midpoint to a resilient member and at opposing edges to a pair of elongate supports. The stressed membrane can be electrostatically switched between a pair of mechanical states having mirror-image symmetry, with the MEM actuator remaining in a quiescent state after a programming voltage is removed. The bistable MEM actuator according to various embodiments of the present invention can be used to form a nonvolatile memory element, an optical modulator (with a pair of mirrors supported above the membrane and moving in synchronism as the membrane is switched), a switchable mirror (with a single mirror supported above the membrane at the midpoint thereof) and a latching relay (with a pair of contacts that open and close as the membrane is switched). Arrays of bistable MEM actuators can be formed for applications including nonvolatile memories, optical displays and optical computing.

  6. Rod drive and latching mechanism

    International Nuclear Information System (INIS)

    Veronesi, L.; Sherwood, D.G.

    1982-01-01

    Hydraulic drive and latching mechanisms for driving reactivity control mechanisms in nuclear reactors are described. Preferably, the pressurized reactor coolant is utilized to raise the drive rod into contact with and to pivot the latching mechanism so as to allow the drive rod to pass the latching mechanism. The pressure in the housing may then be equalized which allows the drive rod to move downwardly into contact with the latching mechanism but to hold the shaft in a raised position with respect to the reactor core. Once again, the reactor coolant pressure may be utilized to raise the drive rod and thus pivot the latching mechanism so that the drive rod passes above the latching mechanism. Again, the mechanism pressure can be equalized which allows the drive rod to fall and pass by the latching mechanism so that the drive rod approaches the reactor core. (author)

  7. Self-Latching Piezocomposite Actuator

    Science.gov (United States)

    Wilkie, William K. (Inventor); Bryant, Robert G. (Inventor); Lynch, Christopher S. (Inventor)

    2017-01-01

    A self-latching piezocomposite actuator includes a plurality of shape memory ceramic fibers. The actuator can be latched by applying an electrical field to the shape memory ceramic fibers. The actuator remains in a latched state/shape after the electrical field is no longer present. A reverse polarity electric field may be applied to reset the actuator to its unlatched state/shape. Applied electric fields may be utilized to provide a plurality of latch states between the latched and unlatched states of the actuator. The self-latching piezocomposite actuator can be used for active/adaptive airfoils having variable camber, trim tabs, active/deformable engine inlets, adaptive or adjustable vortex generators, active optical components such as mirrors that change shapes, and other morphing structures.

  8. Latch-up in CMOS integrated circuits

    International Nuclear Information System (INIS)

    Estreich, D.B.; Dutton, R.W.

    1978-04-01

    An analysis is presented of latch-up in CMOS integrated circuits. A latch-up prediction algorithm has been developed and used to evaluate methods to control latch-up. Experimental verification of the algorithm is demonstrated

  9. Latching micro optical switch

    Science.gov (United States)

    Garcia, Ernest J; Polosky, Marc A

    2013-05-21

    An optical switch reliably maintains its on or off state even when subjected to environments where the switch is bumped or otherwise moved. In addition, the optical switch maintains its on or off state indefinitely without requiring external power. External power is used only to transition the switch from one state to the other. The optical switch is configured with a fixed optical fiber and a movable optical fiber. The movable optical fiber is guided by various actuators in conjunction with a latching mechanism that configure the switch in one position that corresponds to the on state and in another position that corresponds to the off state.

  10. Strong-back safety latch

    International Nuclear Information System (INIS)

    DeSantis, G.N.

    1995-01-01

    The calculation decides the integrity of the safety latch that will hold the strong-back to the pump during lifting. The safety latch will be welded to the strong-back and will latch to a 1.5-in. dia cantilever rod welded to the pump baseplate. The static and dynamic analysis shows that the safety latch will hold the strong-back to the pump if the friction clamps fail and the pump become free from the strong-back. Thus, the safety latch will meet the requirements of the Lifting and Rigging Manual for under the hook lifting for static loading; it can withstand shock loads from the strong-back falling 0.25 inch

  11. Optimization of resistively hardened latches

    International Nuclear Information System (INIS)

    Gagne, G.; Savaria, Y.

    1990-01-01

    The design of digital circuits tolerant to single-event upsets is considered. The results of a study are presented on which an analytical model was used to predict the behavior of a standard resistively hardened latch. It is shown that a worst case analysis for all possible single-event upset situations (on the latch or in the logic) can be derived from studying the effects of a transient disturbed write cycle. The existence of an intrinsic minimum write period to tolerate a transient of a given duration is also demonstrated

  12. Design and measurements of SEU tolerant latches

    CERN Document Server

    Menouni, M; Barbero, M; Beccherle, R; Breugnon, P; Ely, R; Fougeron, D; García-Sciveres, M; Gnani, D; Hemperek, T; Karagounis, M; Kluit, R; Mekkaoui, A; Rozanov, A; Schipper, J-D

    2008-01-01

    Latches based on the Dual Interlocked storage Cell or DICE are very tolerant to Single Event Upsets (SEU). However, for highly scaled processes where the sizes continue to decrease, the data in this latch can be corrupted by an SEU due to charge sharing between adjacent nodes. Some layout considerations are used to improve the tolerance of the DICE latches to SEU and especially the influence of sensitive nodes separation is tested for DICE latches designed with a 130 nm process.

  13. Electrical latching of microelectromechanical devices

    Science.gov (United States)

    Garcia, Ernest J.; Sleefe, Gerard E.

    2004-11-02

    Methods are disclosed for row and column addressing of an array of microelectromechanical (MEM) devices. The methods of the present invention are applicable to MEM micromirrors or memory elements and allow the MEM array to be programmed and maintained latched in a programmed state with a voltage that is generally lower than the voltage required for electrostatically switching the MEM devices.

  14. Control rod drive shaft latch

    International Nuclear Information System (INIS)

    Thorp, A.G. II.

    1976-01-01

    A latch mechanism is operated by differential pressure on a piston to engage the drive shaft for a control rod in a nuclear reactor, thereby preventing the control rod from being ejected from the reactor in case of failure of the control rod drive mechanism housing which is subjected to the internal pressure in the reactor vessel. 6 claims, 4 drawing figures

  15. Sprag solenoid brake

    Science.gov (United States)

    Dane, P. H.

    1972-01-01

    Operation of solenoid braking mechanism is discussed. Illustrations of construction of the brake are provided. Device is used for braking low or medium speed shaft rotations and produces approximately ten times braking torque of similar solenoid brakes.

  16. An analysis of latch-up characteristics and latch-up windows in CMOS integrated circuits

    International Nuclear Information System (INIS)

    Xu Xianguo; Yang Huaimin

    2004-01-01

    Because of topology's complexity, there may be several potential parasitic latch-up paths in a CMOS integrated circuit. All of the latch-up paths may have an effect on each other or one another due to different triggering dose rate, holding voltage and holding current and then one or more latch-up windows may appear. After we analyze the latch-up characteristic of CMOS integrated circuits in detail, a 'three-path' latch-up model is developed and used to explain the latch-up window phenomena reasonably. (authors)

  17. CRDM with separate SCRAM latch engagement and locking

    Energy Technology Data Exchange (ETDEWEB)

    Dodd, Christopher D.; DeSantis, Paul K.; Stambaugh, Kevin J.; Mackovjak, Allan R.; McLaughlin, John P.; Goodyear, Brett T.; Edwards, Michael J.; Ales, Matthew W.

    2018-01-09

    A control rod drive mechanism (CRDM) configured to latch onto the lifting rod of a control rod assembly and including separate latch engagement and latch holding mechanisms. A CRDM configured to latch onto the lifting rod of a control rod assembly and including a four-bar linkage closing the latch, wherein the four-bar linkage biases the latch closed under force of gravity.

  18. A Foot Operated Timeout Room Door Latch.

    Science.gov (United States)

    Foxx, R. M.; And Others

    1982-01-01

    This report describes the design and implementation of a foot operated timeout room door latch that permits staff members to maintain a misbehaving retarded individual in timeout without locking the door. Use of the latch also frees the staff member involved to record behavioral observations or reinforce appropriate behavior. (Author)

  19. Quick release latch for reactor scram

    International Nuclear Information System (INIS)

    Johnson, M.L.; Shawver, B.M.

    1976-01-01

    A simple, reliable, and fast-acting means for releasing a control element and allowing it to be inserted rapidly into the core region of a nuclear reactor for scram purposes is described. A latch mechanism grips a coupling head on a nuclear control element to connect the control element to the control drive assembly. The latch mechanism is closed by tensioning a cable or rod with an actuator. The control element is released by de-energizing the actuator, providing fail-safe, rapid release of the control element to effect reactor shutdown. A sensing rod provides indication that the control element is properly positioned in the latch. Two embodiments are illustrated, one involving a collet-type latch mechanism, the other a pliers-type latch mechanism with the actuator located inside the reactor vessel

  20. Quick release latch for reactor scram

    International Nuclear Information System (INIS)

    Johnson, M.L.; Shawver, B.M.

    1975-01-01

    A simple, reliable, and fast-acting means for releasing a control element and allowing it to be inserted rapidly into the core region of a nuclear reactor for scram purposes is described. A latch mechanism grips a coupling head on a nuclear control element to connect the control element to the control drive assembly. The latch mechanism is closed by tensioning a cable or rod with an actuator. The control element is released by de-energizing the actuator, providing fail-safe, rapid release of the control element to effect reactor shutdown. A sensing rod provides indication that the control element is properly positioned in the latch. Two embodiments are illustrated, one involving a collet-type latch mechanism, the other a pliers-type latch mechanism with the actuator located inside the reactor vessel

  1. Bistable Reflective Etalon (BRET)

    National Research Council Canada - National Science Library

    Shellenbarger, Zane

    2003-01-01

    This project designed, fabricated, and characterized normal-incidence etalon structures at 1550 nm wavelength operation for application, as bistable elements, to photonic analog-to-digital conversion...

  2. ATLAS Solenoid Integration

    CERN Multimedia

    Ruber, R

    Last month the central solenoid was installed in the barrel cryostat, which it shares with the liquid argon calorimeter. Figure 1: Some members of the solenoid and liquid argon teams proudly pose in front of the barrel cryosat, complete with detector and magnet. Some two years ago the central solenoid arrived at CERN after being manufactured and tested in Japan. It was kept in storage until last October when it was finally moved to the barrel cryostat integration area. Here a position survey of the solenoid (with respect to the cryostat's inner warm vessel) was performed. Figure 2: The alignment survey by Dirk Mergelkuhl and Aude Wiart. (EST-SU) At the start of the New Year the solenoid was moved to the cryostat insertion stand. Figure 3: The solenoid on the insertion stand, with Akira Yamamoto the solenoid designer and project leader. Figure 4: Taka Kondo, ATLAS Japan spokesperson, and Shoichi Mizumaki, Toshiba project engineer for the ATLAS solenoid, celebrate the insertion. Aft...

  3. ATLAS solenoid operates underground

    CERN Multimedia

    2006-01-01

    A new phase for the ATLAS collaboration started with the first operation of a completed sub-system: the Central Solenoid. Teams monitoring the cooling and powering of the ATLAS solenoid in the control room. The solenoid was cooled down to 4.5 K from 17 to 23 May. The first current was established the same evening that the solenoid became cold and superconductive. 'This makes the ATLAS Central Solenoid the very first cold and superconducting magnet to be operated in the LHC underground areas!', said Takahiko Kondo, professor at KEK. Though the current was limited to 1 kA, the cool-down and powering of the solenoid was a major milestone for all of the control, cryogenic, power and vacuum systems-a milestone reached by the hard work and many long evenings invested by various teams from ATLAS, all of CERN's departments and several large and small companies. Since the Central Solenoid and the barrel liquid argon (LAr) calorimeter share the same cryostat vacuum vessel, this achievement was only possible in perfe...

  4. The CMS superconducting solenoid

    CERN Multimedia

    Maximilien Brice

    2004-01-01

    The huge solenoid that will generate the magnetic field for the CMS experiment at the LHC is shown stored in the assembly hall above the experimental cavern. The solenoid is made up of five pieces totaling 12.5 m in length and 6 m in diameter. It weighs 220 tonnes and will produce a 4 T magnetic field, 100 000 times the strength of the Earth's magnetic field, storing enough energy to melt 18 tonnes of gold.

  5. High speed non-latching squid binary ripple counter

    International Nuclear Information System (INIS)

    Silver, A.H.; Phillips, R.R.; Sandell, R.D.

    1985-01-01

    High speed, single flux quantum (SFQ) binary scalers are important components in superconducting analog-to-digital converters (ADC). This paper reviews the concept for a SQUID ADC and the design of an SFQ binary ripple counter, and reports the simulation of key components, and fabrication and performance of non-latching SQUID scalers and SFQ binary ripple counters. The SQUIDs were fabricated with Nb/Nb 2 O 5 /PbIn junctions and interconnected by monolithic superconducting transmission lines and isolation resistors. Each SQUID functioned as a bistable flip-flop with the input connected to the center of the device and the output across one junction. All junctions were critically damped to optimize the pulse response. Operation was verified by observing the dc I-V curves of successive SQUIDs driven by a cw pulse train generated on the same chip. Each SQUID exhibited constant-voltage current steps at 1/2 the voltage of the preceding device as expected from the Josephson voltage-to-frequency relation. Steps were observed only for the same voltage polarity of successive devices and for proper phase bias of the SQUID. Binary frequency division was recorded up to 40GHz for devices designed to operate to 28GHz

  6. Burnable absorber rod releasable latching structure

    International Nuclear Information System (INIS)

    Gjertsen, R.K.; Wilson, J.F.

    1987-01-01

    An elongated nuclear reactivity control member, a releasable latching structure useful for releasably attaching the control member at an end to a top nozzle adapter plate of a nuclear fuel assembly is described comprising: (a) a mounting body including an inner plug portion attached to the end of the control member and an outer end portion disposed axially outward from the inner plug portion and the end of the member; and (b) a spring latch disposed about the mounting body and being attached to the outer end portion. The spring latch has at least one latch finger extending toward the inner plug portion of the body and is movable toward and away from the body between an outer latching position in which the finger is adapted to engage a fuel assembly top nozzle adapter plate and retain the elongated member in a stationary relationship with respect to the adapter plate and an inner unlatching position in which the finger is adapted to disengage from the adapter plate and allow removal of the member from the adapter plate

  7. A light writable microfluidic "flash memory": optically addressed actuator array with latched operation for microfluidic applications.

    Science.gov (United States)

    Hua, Zhishan; Pal, Rohit; Srivannavit, Onnop; Burns, Mark A; Gulari, Erdogan

    2008-03-01

    This paper presents a novel optically addressed microactuator array (microfluidic "flash memory") with latched operation. Analogous to the address-data bus mediated memory address protocol in electronics, the microactuator array consists of individual phase-change based actuators addressed by localized heating through focused light patterns (address bus), which can be provided by a modified projector or high power laser pointer. A common pressure manifold (data bus) for the entire array is used to generate large deflections of the phase change actuators in the molten phase. The use of phase change material as the working media enables latched operation of the actuator array. After the initial light "writing" during which the phase is temporarily changed to molten, the actuated status is self-maintained by the solid phase of the actuator without power and pressure inputs. The microfluidic flash memory can be re-configured by a new light illumination pattern and common pressure signal. The proposed approach can achieve actuation of arbitrary units in a large-scale array without the need for complex external equipment such as solenoid valves and electrical modules, which leads to significantly simplified system implementation and compact system size. The proposed work therefore provides a flexible, energy-efficient, and low cost multiplexing solution for microfluidic applications based on physical displacements. As an example, the use of the latched microactuator array as "normally closed" or "normally open" microvalves is demonstrated. The phase-change wax is fully encapsulated and thus immune from contamination issues in fluidic environments.

  8. ATLAS Solenoid Integration

    CERN Multimedia

    Ruber, R

    Last month the central solenoid was installed in the barrel cryostat, which it shares with the liquid argon calorimeter. Some two years ago the central solenoid arrived at CERN after being manufactured and tested in Japan. It was kept in storage until last October when it was finally moved to the barrel cryostat integration area. Here a position survey of the solenoid (with respect to the cryostat's inner warm vessel) was performed. At the start of the New Year the solenoid was moved to the cryostat insertion stand. After a test insertion on 6th February and a few weeks of preparation work it was finally inserted on 27th February. A couple of hectic 24-hours/7-day weeks followed in order to connect all services in the cryostat bulkhead. But last Monday, 15th March, both warm flanges of the cryostat could be closed. In another week's time we expect to finish the connection of the cryogenic cooling lines and the superconducting bus lines with the external services. Then the cool-down and test will commence... ...

  9. Resettable binary latch mechanism for use with paraffin linear motors

    Science.gov (United States)

    Maus, Daryl; Tibbitts, Scott

    1991-01-01

    A new resettable Binary Latch Mechanism was developed utilizing a paraffin actuator as the motor. This linear actuator alternately latches between extended and retracted positions, maintaining either position with zero power consumption. The design evolution and kinematics of the latch mechanism are presented, as well as the development problems and lessons that were learned.

  10. CMOS latch-up analysis and prevention

    International Nuclear Information System (INIS)

    Shafer, B.D.

    1975-06-01

    An analytical model is presented which develops relationships between ionization rates, minority carrier lifetimes, and latch-up in bulk CMOS integrated circuits. The basic mechanism for latch-up is the SCR action reported by Gregory and Shafer. The SCR is composed of a vertical NPN transistor formed by the N-channel source diffusion, the P-Well, and the N-substrate. The second part of the SCR is the lateral PNP transistor made up of the P-channel source diffusion, the N-substrate, and P-Well. It is shown that the NPN transistor turns on due to photocurrent-induced lateral voltage drops in the base of the transistor. The gain of this double diffused transistor has been shown to be as high as 100. Therefore, the transistor action of this device produces a much larger current flow in the substrate. This transistor current adds to that produced by the P-Well diode photocurrent in the substrate. It is found that the combined flow of current in the substrate forward biases the base emitter junction of the PNP device long before this could occur due to the P-Well photocurrent alone. The analysis indicated that a CD4007A CMOS device biased in the normal mode of operation should latch at about 2 . 10 8 rads/sec. Experimental results produced latch-up at 1 to 3 . 10 8 rads/sec. (U.S.)

  11. Passive Magnetic Latching Mechanisms For Robotic Applications

    KAUST Repository

    Fiaz, Usman

    2017-04-01

    This thesis investigates the passive magnetic latching mechanism designs for autonomous aerial grasping and programmable self-assembly. The enormous latching potential of neodymium magnets is a well-established fact when it comes to their ability to interact with ferrous surfaces in particular. The force of attraction or repulsion among the magnets is strong enough to keep the levitation trains, and high speed transportation pods off the rails. But such utilization of these desirable magnetic properties in commercial applications, comes at a cost of high power consumption since the magnets used are usually electromagnets. On the other hand, we explore some useful robotic applications of passive (and hence low cost) magnetic latching; which are of vital importance in autonomous aerial transportation, automated drone-based package deliveries, and programmable self-assembly and self-reconfigurable systems. We propose, and implement a novel, attach/detach mechatronic mechanism, based on passive magnetic latching of permanent magnets for usBots; our indige- nously built programmable self-assembly robots, and show that it validates the game theoretic self-assembly algorithms. Another application addressed in this thesis is the utilization of permanent magnets in autonomous aerial grasping for Unmanned Aerial Vehicles (UAVs). We present a novel gripper design for ferrous objects with a passive magnetic pick up and an impulse based drop. For both the applications, we highlight the importance, simplicity and effectiveness of the proposed designs while providing a brief comparison with the other technologies out there.

  12. 49 CFR 236.801 - Shoe, latch.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Shoe, latch. 236.801 Section 236.801 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.801...

  13. Latching device for nuclear reactor housing

    International Nuclear Information System (INIS)

    Barnes, J.G.

    1981-01-01

    A latching device for use in liquid metal cooled nuclear reactors is described which is not detached under normal operational loads on the absorber sub-assemblies. The sub-assemblies are however easily detached for repair or replacement. (U.K.)

  14. Prevention of CMOS latch-up by gold doping

    International Nuclear Information System (INIS)

    Dawes, W.R.; Derbenwick, G.F.

    1976-01-01

    CMOS integrated circuits fabricated with the bulk silicon technology typically exhibit latch-up effects in either an ionizing radiation environment or an overvoltage stress condition. The latch-up effect has been shown to arise from regenerative switching, analogous to an SCR, in the adjacent parasitic bipolar transistors formed during the fabrication of a bulk CMOS device. Once latch-up has been initiated, it is usually self-sustaining and eventually destructive. Naturally, the circuit is inoperative during latch-up. This paper discusses a generic process technique that prevents the latch-up mechanism in CMOS devices

  15. CMS (Compact Muon Solenoid)

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    The milestone workshops on LHC experiments in Aachen in 1990 and at Evian in 1992 provided the first sketches of how LHC detectors might look. The concept of a compact general-purpose LHC experiment based on a solenoid to provide the magnetic field was first discussed at Aachen, and the formal Expression of Interest was aired at Evian. It was here that the Compact Muon Solenoid (CMS) name first became public. Optimizing first the muon detection system is a natural starting point for a high luminosity (interaction rate) proton-proton collider experiment. The compact CMS design called for a strong magnetic field, of some 4 Tesla, using a superconducting solenoid, originally about 14 metres long and 6 metres bore. (By LHC standards, this warrants the adjective 'compact'.) The main design goals of CMS are: 1 - a very good muon system providing many possibilities for momentum measurement (physicists call this a 'highly redundant' system); 2 - the best possible electromagnetic calorimeter consistent with the above; 3 - high quality central tracking to achieve both the above; and 4 - an affordable detector. Overall, CMS aims to detect cleanly the diverse signatures of new physics by identifying and precisely measuring muons, electrons and photons over a large energy range at very high collision rates, while also exploiting the lower luminosity initial running. As well as proton-proton collisions, CMS will also be able to look at the muons emerging from LHC heavy ion beam collisions. The Evian CMS conceptual design foresaw the full calorimetry inside the solenoid, with emphasis on precision electromagnetic calorimetry for picking up photons. (A light Higgs particle will probably be seen via its decay into photon pairs.) The muon system now foresaw four stations. Inner tracking would use silicon microstrips and microstrip gas chambers, with over 10 7 channels offering high track finding efficiency. In the central CMS barrel, the tracking elements are

  16. LCLS Gun Solenoid Design Considerations

    International Nuclear Information System (INIS)

    Schmerge, John

    2010-01-01

    The LCLS photocathode rf gun requires a solenoid immediately downstream for proper emittance compensation. Such a gun and solenoid have been operational at the SSRL Gun Test Facility (GTF) for over eight years. Based on magnetic measurements and operational experience with the GTF gun solenoid multiple modifications are suggested for the LCLS gun solenoid. The modifications include adding dipole and quadrupole correctors inside the solenoid, increasing the bore to accommodate the correctors, decreasing the mirror plate thickness to allow the solenoid to move closer to the cathode, cutouts in the mirror plate to allow greater optical clearance with grazing incidence cathode illumination, utilizing pancake coil mirror images to compensate the first and second integrals of the transverse fields and incorporating a bipolar power supply to allow for proper magnet standardization and quick polarity changes. This paper describes all these modifications plus the magnetic measurements and operational experience leading to the suggested modifications.

  17. Magnetic latch trigger for inherent shutdown assembly

    International Nuclear Information System (INIS)

    Sowa, E.S.

    1976-01-01

    An inherent shutdown assembly for a nuclear reactor is provided. A neutron absorber is held ready to be inserted into the reactor core by a magnetic latch. The latch includes a magnet whose lines of force are linked by a yoke of material whose Curie point is at the critical temperature of the reactor at which the neutron absorber is to be inserted into the reactor core. The yoke is in contact with the core coolant or fissionable material so that when the coolant or the fissionable material increase in temperature above the Curie point the yoke loses its magnetic susceptibility and the magnetic link is broken, thereby causing the absorber to be released into the reactor core. 6 claims, 3 figures

  18. Molecular quantum cellular automata cell design trade-offs: latching vs. power dissipation.

    Science.gov (United States)

    Rahimi, Ehsan; Reimers, Jeffrey R

    2018-06-20

    The use of molecules to enact quantum cellular automata (QCA) cells has been proposed as a new way for performing electronic logic operations at sub-nm dimensions. A key question that arises concerns whether chemical or physical processes are to be exploited. The use of chemical reactions allows the state of a switch element to be latched in molecular form, making the output of a cell independent of its inputs, but costs energy to do the reaction. Alternatively, if purely electronic polarization is manipulated then no internal latching occurs, but no power is dissipated provided the fields from the inputs change slowly compared to the molecular response times. How these scenarios pan out is discussed by considering calculated properties of the 1,4-diallylbutane cation, a species often used as a paradigm for molecular electronic switching. Utilized are results from different calculation approaches that depict the ion either as a charge-localized mixed-valence compound functioning as a bistable switch, or else as an extremely polarizable molecule with a delocalized electronic structure. Practical schemes for using molecular cells in QCA and other devices emerge.

  19. What is refractive optical bistability

    International Nuclear Information System (INIS)

    Dzhehov, Tomislav

    1993-01-01

    The basic elements of the theory of refractive optical bistability, assuming mediums with linear absorption are given. Special attention is paid to bistable etalons of semiconductor materials an oxide glasses, since some of them are considered as promising components for optical bistability applications. The design optimization of such devices for minimum switching intensity is analyzed. Computer simulation of the transfer characteristic recording for two InSb etalons is presented. (author)

  20. The unsaturated bistable stochastic resonance system.

    Science.gov (United States)

    Zhao, Wenli; Wang, Juan; Wang, Linze

    2013-09-01

    We investigated the characteristics of the output saturation of the classical continuous bistable system (saturation bistable system) and its impact on stochastic resonance (SR). We further proposed a piecewise bistable SR system (unsaturated bistable system) and developed the expression of signal-to-noise ratio (SNR) using the adiabatic approximation theory. Compared with the saturation bistable system, the SNR is significantly improved in our unsaturated bistable SR system. The numerical simulation showed that the unsaturated bistable system performed better in extracting weak signals from strong background noise than the saturation bistable system.

  1. Controlling bistability by linear augmentation

    International Nuclear Information System (INIS)

    Sharma, Pooja Rani; Shrimali, Manish Dev; Prasad, Awadhesh; Feudel, Ulrike

    2013-01-01

    In many bistable oscillating systems only one of the attractors is desired to possessing certain system performance. We present a method to drive a bistable system to a desired target attractor by annihilating the other one. This shift from bistability to monostability is achieved by augmentation of the nonlinear oscillator with a linear control system. For a proper choice of the control function one of the attractors disappears at a critical coupling strength in an control-induced boundary crisis. This transition from bistability to monostability is demonstrated with two paradigmatic examples, the autonomous Chua oscillator and a neuronal system with a periodic input signal.

  2. Bistable Mechanisms for Space Applications.

    Science.gov (United States)

    Zirbel, Shannon A; Tolman, Kyler A; Trease, Brian P; Howell, Larry L

    2016-01-01

    Compliant bistable mechanisms are monolithic devices with two stable equilibrium positions separated by an unstable equilibrium position. They show promise in space applications as nonexplosive release mechanisms in deployment systems, thereby eliminating friction and improving the reliability and precision of those mechanical devices. This paper presents both analytical and numerical models that are used to predict bistable behavior and can be used to create bistable mechanisms in materials not previously feasible for compliant mechanisms. Materials compatible with space applications are evaluated for use as bistable mechanisms and prototypes are fabricated in three different materials. Pin-puller and cutter release mechanisms are proposed as potential space applications.

  3. Distributed processing in bistable perception

    NARCIS (Netherlands)

    Knapen, T.H.J.

    2007-01-01

    A very incisive way of studying visual awareness and the mechanisms that underlie it, it to use bistable perception. In bistable perception, an observer's perceptual state alternates between one interpretation and its mutually exclusive counterpart while the stimulus remains the same. This gives us

  4. SSC detector solenoid

    International Nuclear Information System (INIS)

    Fast, R.W.; Grimson, J.H.; Kephart, R.D.; Krebs, H.J.; Stone, M.E.; Theriot, E.D.; Wands, R.H.

    1989-01-01

    A detector utilizing a superconducting solenoid is being discussed for the Superconducting Super Collider (SSC). A useful field volume of 8 m diameter x 16 m length at 1.5-2 T (--1 GJ at 2T) is required. It has been decided that all of the particle physics calorimetry will be inside the bore of the solenoid and that there is no need for the coil and cryostat to be ''thin'' in radiation lengths. An iron yoke will reduce the excitation required and will provide muon identification and a redundant momentum measurement of the muons. The authors have developed a conceptual design to meet these requirements. The magnet will use a copper-stabilized Nb-Ti conductor sized for a cryostable pool boiling heat flux --0.025 W/cm/sup 2/. A thermosiphon from a storage vessel above the cryostat will be used to prevent bubble stagnation in the liquid helium bath. The operating current, current density, coil subdivision and dump resistor have been chosen to guarantee that the coil will be undamaged should a quench occur. The axial electromagnetic force will be reacted by metallic support links; the stainless steel coil case will support the radial force. The 5000 metric tons of calorimetry will be supported from the iron yoke through a trussed cylindrical shell structure separate from the cryostat. The coil and case, radiation shield and stainless vacuum vessel would be fabricated and cryogenically tested as two 8-m sections. These would be lowered into the underground experimental hall and installed into the iron flux return yoke to provide the required 16-m length

  5. Reversibly Bistable Flexible Electronics

    KAUST Repository

    Alfaraj, Nasir

    2015-05-01

    Introducing the notion of transformational silicon electronics has paved the way for integrating various applications with silicon-based, modern, high-performance electronic circuits that are mechanically flexible and optically semitransparent. While maintaining large-scale production and prototyping rapidity, this flexible and translucent scheme demonstrates the potential to transform conventionally stiff electronic devices into thin and foldable ones without compromising long-term performance and reliability. In this work, we report on the fabrication and characterization of reversibly bistable flexible electronic switches that utilize flexible n-channel metal-oxide-semiconductor field-effect transistors. The transistors are fabricated initially on rigid (100) silicon substrates before they are peeled off. They can be used to control flexible batches of light-emitting diodes, demonstrating both the relative ease of scaling at minimum cost and maximum reliability and the feasibility of integration. The peeled-off silicon fabric is about 25 µm thick. The fabricated devices are transferred to a reversibly bistable flexible platform through which, for example, a flexible smartphone can be wrapped around a user’s wrist and can also be set back to its original mechanical position. Buckling and cyclic bending of such host platforms brings a completely new dimension to the development of flexible electronics, especially rollable displays.

  6. Latch-up and radiation integrated circuit--LURIC: a test chip for CMOS latch-up investigation

    International Nuclear Information System (INIS)

    Estreich, D.B.

    1978-11-01

    A CMOS integrated circuit test chip (Latch-Up and Radiation Integrated Circuit--LURIC) designed for CMOS latch-up and radiation effects research is described. The purpose of LURIC is (a) to provide information on the physics of CMOS latch-up, (b) to study the layout dependence of CMOS latch-up, and (c) to provide special latch-up test structures for the development and verification of a latch-up model. Many devices and test patterns on LURIC are also well suited for radiation effects studies. LURIC contains 86 devices and related test structures. A 12-layer mask set allows both metal gate CMOS and silicon gate ELA (Extended Linear Array) CMOS to be fabricated. Six categories of test devices and related test structures are included. These are (a) the CD4007 metal gate CMOS IC with auxiliary test structures, (b) ELA CMOS cells, (c) field-aided lateral pnp transistors, (d) p-well and substrate spreading resistance test structures, (e) latch-up test structures (simplified symmetrical latch-up paths), and (f) support test patterns (e.g., MOS capacitors, p + n diodes, MOS test transistors, van der Pauw and Kelvin contact resistance test patterns, etc.). A standard probe pattern array has been used on all twenty-four subchips for testing convenience

  7. Solenoidal fusion system

    International Nuclear Information System (INIS)

    Linlor, W.I.

    1980-01-01

    This invention discloses apparatus and methods to produce nuclear fusion utilizing fusible material in the form of high energy ion beams confined in magnetic fields. For example, beams of deuterons and tritons are injected in the same direction relative to the axis of a vacuum chamber. The ion beams are confined by the magnetic fields of long solenoids. The products of the fusion reactions, such as neutrons and alpha particles, escape to the wall surrounding the vacuum chamber, producing heat. The momentum of the deuterons is approximately equal to the momentum of the tritons, so that both types of ions follow the same path in the confining magnetic field. The velocity of the deuteron is sufficiently greater than the velocity of the triton so that overtaking collisions occur at a relative velocity which produces a high fusion reaction cross section. Electrons for space charge neutralization are obtained by ionization of residual gas in the vacuum chamber, and additionally from solid material (Irradiated with ultra-violet light or other energetic radiation) adjacent to the confinement region. For start-up operation, injected high-energy molecular ions can be dissociated by intense laser beam, producing trapping via change of charge state. When sufficiently intense deuteron and triton beams have been produced, the laser beam can be removed, and subsequent change of charge state can be achieved by collisions

  8. Inauguration of the CMS solenoid

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    In early 2005 the final piece of the CMS solenoid magnet arrived, marked by this ceremony held in the CMS assembly hall at Cessy, France. The solenoid is made up of five pieces totaling 12.5 m in length and 6 m in diameter. Weighing 220 tonnes, it will produce a 4 T magnetic field, 100 000 times the strength of the Earth's magnetic field and store enough energy to melt 18 tonnes of gold.

  9. Optimization of Bistable Viscoelastic Systems

    DEFF Research Database (Denmark)

    Jensen, Kristian Ejlebjærg; Szabo, Peter; Okkels, Fridolin

    2014-01-01

    driving pressure corresponding to the point of bistability, such that the effect is enhanced. The point of bistability is, however, not explicitly contained in the solution, so we opt for a heuristic approach based on the dissipation ratio between the asymmetric and unstable symmetric flow solutions. We...... find a design that significantly reduces the driving pressure required for bistability, and furthermore is in agreement with the approach followed by experimental researchers. Furthermore, by comparing the two asymmetric solutions, we succesfully apply the same approach to a problem with two fluids...

  10. Bistable amphoteric centers in semiconductors

    International Nuclear Information System (INIS)

    Nikitina, A. G.; Zuev, V. V.

    2008-01-01

    It is shown that, at thermodynamic equilibrium, the release of charge carriers from the localized states of bistable amphoteric centers into quasi-free states depends on the degree of compensation. This brings about different functional dependences of the concentration of free charge carriers on temperature. It is found that, in uncompensated semiconductors, the concentration of free charge carriers follows the same dependence in the case of bistable amphoteric centers and bistable amphoteric U - centers, although the distributions of charge carriers over the charge states and configurations are different for these types of centers. The results can be used for interpreting various experimental data insufficiently explained in the context of the traditional approach

  11. A Miniature Coupled Bistable Vibration Energy Harvester

    International Nuclear Information System (INIS)

    Zhu, D; Arthur, D C; Beeby, S P

    2014-01-01

    This paper reports the design and test of a miniature coupled bistable vibration energy harvester. Operation of a bistable structure largely depends on vibration amplitude rather than frequency, which makes it very promising for wideband vibration energy harvesting applications. A coupled bistable structure consists of a pair of mobile magnets that create two potential wells and thus the bistable phenomenon. It requires lower excitation to trigger bistable operation compared to conventional bistable structures. Based on previous research, this work focused on miniaturisation of the coupled bistable structure for energy harvesting application. The proposed bistable energy harvester is a combination of a Duffing's nonlinear structure and a linear assisting resonator. Experimental results show that the output spectrum of the miniature coupled bistable vibration energy harvester was the superposition of several spectra. It had a higher maximum output power and a much greater bandwidth compared to simply the Duffing's structure without the assisting resonator

  12. Bistability of Cavity Magnon Polaritons

    Science.gov (United States)

    Wang, Yi-Pu; Zhang, Guo-Qiang; Zhang, Dengke; Li, Tie-Fu; Hu, C.-M.; You, J. Q.

    2018-01-01

    We report the first observation of the magnon-polariton bistability in a cavity magnonics system consisting of cavity photons strongly interacting with the magnons in a small yttrium iron garnet (YIG) sphere. The bistable behaviors emerged as sharp frequency switchings of the cavity magnon polaritons (CMPs) and related to the transition between states with large and small numbers of polaritons. In our experiment, we align, respectively, the [100] and [110] crystallographic axes of the YIG sphere parallel to the static magnetic field and find very different bistable behaviors (e.g., clockwise and counter-clockwise hysteresis loops) in these two cases. The experimental results are well fitted and explained as being due to the Kerr nonlinearity with either a positive or negative coefficient. Moreover, when the magnetic field is tuned away from the anticrossing point of CMPs, we observe simultaneous bistability of both magnons and cavity photons by applying a drive field on the lower branch.

  13. An advanced SEU tolerant latch based on error detection

    Science.gov (United States)

    Xu, Hui; Zhu, Jianwei; Lu, Xiaoping; Li, Jingzhao

    2018-05-01

    This paper proposes a latch that can mitigate SEUs via an error detection circuit. The error detection circuit is hardened by a C-element and a stacked PMOS. In the hold state, a particle strikes the latch or the error detection circuit may cause a fault logic state of the circuit. The error detection circuit can detect the upset node in the latch and the fault output will be corrected. The upset node in the error detection circuit can be corrected by the C-element. The power dissipation and propagation delay of the proposed latch are analyzed by HSPICE simulations. The proposed latch consumes about 77.5% less energy and 33.1% less propagation delay than the triple modular redundancy (TMR) latch. Simulation results demonstrate that the proposed latch can mitigate SEU effectively. Project supported by the National Natural Science Foundation of China (Nos. 61404001, 61306046), the Anhui Province University Natural Science Research Major Project (No. KJ2014ZD12), the Huainan Science and Technology Program (No. 2013A4011), and the National Natural Science Foundation of China (No. 61371025).

  14. Temporal nonlocality in bistable perception

    Science.gov (United States)

    Atmanspacher, Harald; Filk, Thomas

    2012-12-01

    A novel conceptual framework for theoretical psychology is presented and illustrated for the example of bistable perception. A basic formal feature of this framework is the non-commutativity of operations acting on mental states. A corresponding model for the bistable perception of ambiguous stimuli, the Necker-Zeno model, is sketched and some empirical evidence for it so far is described. It is discussed how a temporal nonlocality of mental states, predicted by the model, can be understood and tested.

  15. Dirac equation in magnetic-solenoid field

    Energy Technology Data Exchange (ETDEWEB)

    Gavrilov, S.P. [Dept. Fisica e Quimica, UNESP, Campus de Guaratingueta (Brazil); Gitman, D.M.; Smirnov, A.A. [Instituto de Fisica, Universidade de Sao Paulo (Brazil)

    2004-07-01

    We consider the Dirac equation in the magnetic-solenoid field (the field of a solenoid and a collinear uniform magnetic field). For the case of Aharonov-Bohm solenoid, we construct self-adjoint extensions of the Dirac Hamiltonian using von Neumann's theory of deficiency indices. We find self-adjoint extensions of the Dirac Hamiltonian and boundary conditions at the AB solenoid. Besides, for the first time, solutions of the Dirac equation in the magnetic-solenoid field with a finite radius solenoid were found. We study the structure of these solutions and their dependence on the behavior of the magnetic field inside the solenoid. Then we exploit the latter solutions to specify boundary conditions for the magnetic-solenoid field with Aharonov-Bohm solenoid. (orig.)

  16. Perceptual incongruence influences bistability and cortical activation

    NARCIS (Netherlands)

    Brouwer, G.J.; Tong, F.; Hagoort, P.; van Ee, R.

    2009-01-01

    We employed a parametric psychophysical design in combination with functional imaging to examine the influence of metric changes in perceptual incongruence on perceptual alternation rates and cortical responses. Subjects viewed a bistable stimulus defined by incongruent depth cues; bistability

  17. GABA shapes the dynamics of bistable perception

    NARCIS (Netherlands)

    van Loon, A.M.; Knapen, T.; Scholte, H.S.; St. John-Saaltink, E.; Donner, T.H.; Lamme, V.A.F.

    2013-01-01

    Sometimes, perception fluctuates spontaneously between two distinct interpretations of a constant sensory input. These bistable perceptual phenomena provide a unique window into the neural mechanisms that create the contents of conscious perception. Models of bistable perception posit that mutual

  18. Optical bistability without the rotating wave approximation

    Energy Technology Data Exchange (ETDEWEB)

    Sharaby, Yasser A., E-mail: Yasser_Sharaby@hotmail.co [Physics Department, Faculty of Applied Sciences, Suez Canal University, Suez (Egypt); Joshi, Amitabh, E-mail: ajoshi@eiu.ed [Department of Physics, Eastern Illinois University, Charleston, IL 61920 (United States); Hassan, Shoukry S., E-mail: Shoukryhassan@hotmail.co [Mathematics Department, College of Science, University of Bahrain, P.O. Box 32038 (Bahrain)

    2010-04-26

    Optical bistability for two-level atomic system in a ring cavity is investigated outside the rotating wave approximation (RWA) using non-autonomous Maxwell-Bloch equations with Fourier decomposition up to first harmonic. The first harmonic output field component exhibits reversed or closed loop bistability simultaneously with the usual (anti-clockwise) bistability in the fundamental field component.

  19. Optical bistability without the rotating wave approximation

    International Nuclear Information System (INIS)

    Sharaby, Yasser A.; Joshi, Amitabh; Hassan, Shoukry S.

    2010-01-01

    Optical bistability for two-level atomic system in a ring cavity is investigated outside the rotating wave approximation (RWA) using non-autonomous Maxwell-Bloch equations with Fourier decomposition up to first harmonic. The first harmonic output field component exhibits reversed or closed loop bistability simultaneously with the usual (anti-clockwise) bistability in the fundamental field component.

  20. Bistable microvalve and microcatheter system

    Science.gov (United States)

    Seward, Kirk Patrick

    2003-05-20

    A bistable microvalve of shape memory material is operatively connected to a microcatheter. The bistable microvalve includes a tip that can be closed off until it is in the desired position. Once it is in position it can opened and closed. The system uses heat and pressure to open and close the microvalve. The shape memory material will change stiffness and shape when heated above a transition temperature. The shape memory material is adapted to move from a first shape to a second shape, either open or closed, where it can perform a desired function.

  1. Optical bistability controlling light with light

    CERN Document Server

    Gibbs, Hyatt

    1985-01-01

    Optical Bistability: Controlling Light with Light focuses on optical bistability in nonlinear optical systems. Emphasis is on passive (non-laser) systems that exhibit reversible bistability with input intensity as the hysteresis variable, along with the physics and the potential applications of such systems for nonlinear optical signal processing. This book consists of seven chapters and begins with a historical overview of optical bistability in lasers and passive systems. The next chapter describes steady-state theories of optical bistability, including the Bonifacio-Lugiato model, as we

  2. Flexible Bistable Cholesteric Reflective Displays

    Science.gov (United States)

    Yang, Deng-Ke

    2006-03-01

    Cholesteric liquid crystals (ChLCs) exhibit two stable states at zero field condition-the reflecting planar state and the nonreflecting focal conic state. ChLCs are an excellent candidate for inexpensive and rugged electronic books and papers. This paper will review the display cell structure,materials and drive schemes for flexible bistable cholesteric (Ch) reflective displays.

  3. Bi-stable optical actuator

    Science.gov (United States)

    Holdener, Fred R.; Boyd, Robert D.

    2000-01-01

    The present invention is a bi-stable optical actuator device that is depowered in both stable positions. A bearing is used to transfer motion and smoothly transition from one state to another. The optical actuator device may be maintained in a stable position either by gravity or a restraining device.

  4. Stabilization of superconducting dry solenoids

    International Nuclear Information System (INIS)

    Urata, M.; Maeda, H.

    1989-01-01

    Premature quenches in superconducting solenoids, wound with Formvar coated NbTi conductors, have been studied. Some model coils were tested wound with various winding tensions. The experimental results are discussed considering the calculated stress distribution for coil winding, cool-down to liquid helium temperature, and energization at 4.2 K. /Some mechanisms of premature quenches are classified by the winding tension. Some stabilization methods are presented based on these quench mechanisms

  5. Free association transitions in models of cortical latching dynamics

    International Nuclear Information System (INIS)

    Russo, Eleonora; Treves, Alessandro; Kropff, Emilio; Namboodiri, Vijay M K

    2008-01-01

    Potts networks, in certain conditions, hop spontaneously from one discrete attractor state to another, a process we have called latching dynamics. When continuing indefinitely, latching can serve as a model of infinite recursion, which is nontrivial if the matrix of transition probabilities presents a structure, i.e. a rudimentary grammar. We show here, with computer simulations, that latching transitions cluster in a number of distinct classes: effectively random transitions between weakly correlated attractors; structured, history-dependent transitions between attractors with intermediate correlations; and oscillations between pairs of closely overlapping attractors. Each type can be described by a reduced set of equations of motion, which, once numerically integrated, matches simulations results. We propose that the analysis of such equations may offer clues on how to embed meaningful grammatical structures into more realistic models of specific recursive processes

  6. Latch-up control in CMOS integrated circuits

    International Nuclear Information System (INIS)

    Ochoa, A. Jr.; Estreich, D.B.; Dawes, W.R. Jr.

    1979-01-01

    The potential for latch-up, a pnpn self-sustaining low impedance state, is inherent in standard bulk CMOS structures. Under normal bias, the parasitic SCR is in its blocking state, but if subjected to a high-voltage spike or if exposed to an ionizing environment, triggering may occur. Prevention of latch-up has been achieved by lifetime control methods such as gold doping or neutron irradiation and by modifying the structure with buried layers. Smaller, next-generation CMOS designs will enhance parasitic action making the problem a concern for other than military or space applications alone. Latch-up control methods presently employed are surveyed. Their adaptability to VSLI designs is analyzed

  7. Free association transitions in models of cortical latching dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Russo, Eleonora; Treves, Alessandro; Kropff, Emilio [SISSA, Cognitive Neuroscience, via Beirut 4, 34014 Trieste (Italy); Namboodiri, Vijay M K [Department of Physics, IIT Bombay, Powai, Mumbai, India 400076 (India)], E-mail: russo@sissa.it, E-mail: vijay_mkn@iitb.ac.in, E-mail: ale@sissa.it, E-mail: kropff@sissa.it

    2008-01-15

    Potts networks, in certain conditions, hop spontaneously from one discrete attractor state to another, a process we have called latching dynamics. When continuing indefinitely, latching can serve as a model of infinite recursion, which is nontrivial if the matrix of transition probabilities presents a structure, i.e. a rudimentary grammar. We show here, with computer simulations, that latching transitions cluster in a number of distinct classes: effectively random transitions between weakly correlated attractors; structured, history-dependent transitions between attractors with intermediate correlations; and oscillations between pairs of closely overlapping attractors. Each type can be described by a reduced set of equations of motion, which, once numerically integrated, matches simulations results. We propose that the analysis of such equations may offer clues on how to embed meaningful grammatical structures into more realistic models of specific recursive processes.

  8. An SEU-hardened latch with a triple-interlocked structure

    International Nuclear Information System (INIS)

    Li Yuanqing; Yao Suying; Xu Jiangtao; Gao Jing

    2012-01-01

    A single event upset (SEU) tolerant latch with a triple-interlocked structure is presented. Its self-recovery mechanism is implemented by using three pairs of guard-gates and inverters to construct feedback lines inside the structure. This latch effectively suppresses the effects of charge deposition at any single internal node caused by particle strikes. Three recently reported SEU-hardened latches are chosen and compared with this latch in terms of reliability. The potential problems that these three latches could still get flipped due to single event effects or single event effects plus crosstalk coupling are pointed out, which can be mitigated by this proposed latch. The SEU tolerance of each latch design is evaluated through circuit-level SEU injection simulation. Furthermore, discussions on the crosstalk robustness and some other characteristics of these latches are also presented. (semiconductor integrated circuits)

  9. Design of SC solenoid with high homogeneity

    International Nuclear Information System (INIS)

    Yang Xiaoliang; Liu Zhong; Luo Min; Luo Guangyao; Kang Qiang; Tan Jie; Wu Wei

    2014-01-01

    A novel kind of SC (superconducting) solenoid coil is designed to satisfy the homogeneity requirement of the magnetic field. In this paper, we first calculate the current density distribution of the solenoid coil section through the linear programming method. Then a traditional solenoid and a nonrectangular section solenoid are designed to produce a central field up to 7 T with a homogeneity to the greatest extent. After comparison of the two solenoid coils designed in magnet field quality, fabrication cost and other aspects, the new design of the nonrectangular section of a solenoid coil can be realized through improving the techniques of framework fabrication and winding. Finally, the outlook and error analysis of this kind of SC magnet coil are also discussed briefly. (authors)

  10. Quench simulation in the thin superconducting solenoid

    International Nuclear Information System (INIS)

    Tominaka, T.; Takasaki, M.; Wake, M.; Yamada, R.

    1983-07-01

    The propagation velocities of a normal zone were calculated for a 1 mdiameter x 1 m superconducting solenoid and for a 3 mdiameter x 5 m thin solenoid based on a simple model using the one-dimensional thermal equation. The quench back effect can be observed in certain conditions. The quench of the large thin solenoid was also simulated by using the computer program 'QUENCH'. (author)

  11. Bistability in a laser with injected signal

    International Nuclear Information System (INIS)

    Dorobantu, I.A.; Vlad, V.I.; Ursu, I.

    1987-04-01

    A unified description of bistability is given in free running lasers, optical bistable devices, ring lasers and lasers with an injected signal (LIS). A general review of laser instabilities is also presented in the frame of the theory of elementary catastrophes, emphasizing the apparence of higher order catastrophes in the case of a LIS suggesting thus a possibility to devise from first principles the whole hierarchy of laser instabilities. Experimental results on the bistability in the polarisation of LIS are also discussed. (authors)

  12. A broadband electromagnetic energy harvester with a coupled bistable structure

    International Nuclear Information System (INIS)

    Zhu, D; Beeby, S P

    2013-01-01

    This paper investigates a broadband electromagnetic energy harvester with a coupled bistable structure. Both analytical model and experimental results showed that the coupled bistable structure requires lower excitation force to trigger bistable operation than conventional bistable structures. A compact electromagnetic vibration energy harvester with a coupled bistable structure was implemented and tested. It was excited under white noise vibrations. Experimental results showed that the coupled bistable energy harvester can achieve bistable operation with lower excitation amplitude and generate more output power than both conventional bistable and linear energy harvesters under white noise excitation

  13. Solenoid System for PRISM and COMET

    International Nuclear Information System (INIS)

    Yoshida, Makoto

    2008-01-01

    An experiment of searching for coherent neutrino-less conversion of muons to electron conversion in muonic atom, μ - +N(A,Z)→e - +N(A,Z), is powerful probe for new physics phenomena beyond the Standard Model. We offer the experiment at a sensitivity of B(μ - N→e - N) -16 with muon beamline consisting of high-field pion capture solenoids, curved solenoids to select beam momenta, and a curved solenoid spectrometer to detect μ - -e - conversion with low-counting-rate conditions. Design of superconducting solenoid magnets of pion capture and transport beam line has been studied and is described in this paper

  14. Progress in ATLAS central solenoid magnet

    CERN Document Server

    Yamamoto, A; Makida, Y; Tanaka, K; Haruyama, T; Yamaoka, H; Kondo, T; Mizumaki, S; Mine, S; Wada, K; Meguro, S; Sotoki, T; Kikuchi, K; ten Kate, H H J

    2000-01-01

    The ATLAS central solenoid magnet is being developed to provide a magnetic field of 2 Tesla in the central tracking volume of the ATLAS detector under construction at the CERN/LHC project. The solenoid coil design features high-strength aluminum stabilized superconductor to make the coil thinnest while maintaining its stability and the pure-aluminum strip technique for quench protection and safety. The solenoid coil is installed in a common cryostat with the LAr calorimeter in order to minimize the cryostat wall. A transparency of 0.66 radiation length is achieved with these integrated efforts. The progress in the solenoid coil fabrication is reported. (8 refs).

  15. A bistable mechanism for directional sensing

    International Nuclear Information System (INIS)

    Beta, C; Amselem, G; Bodenschatz, E

    2008-01-01

    We present a generic mechanism for directional sensing in eukaryotic cells that is based on bistable dynamics. As the key feature of this modeling approach, the velocity of trigger waves in the bistable sensing system changes its sign across cells that are exposed to an external chemoattractant gradient. This is achieved by combining a two-component activator/inhibitor system with a bistable switch that induces an identical symmetry breaking for arbitrary gradient input signals. A simple kinetic example is designed to illustrate the dynamics of a bistable directional sensing mechanism in numerical simulations

  16. Central Solenoid Insert Technical Specification

    Energy Technology Data Exchange (ETDEWEB)

    Martovetsky, Nicolai N [ORNL; Smirnov, Alexandre [ORNL

    2011-09-01

    The US ITER Project Office (USIPO) is responsible for the ITER central solenoid (CS) contribution to the ITER project. The Central Solenoid Insert (CSI) project will allow ITER validation the appropriate lengths of the conductors to be used in the full-scale CS coils under relevant conditions. The ITER Program plans to build and test a CSI to verify the performance of the CS conductor. The CSI is a one-layer solenoid with an inner diameter of 1.48 m and a height of 4.45 m between electric terminal ends. The coil weight with the terminals is approximately 820 kg without insulation. The major goal of the CSI is to measure the temperature margin of the CS under the ITER direct current (DC) operating conditions, including determining sensitivity to load cycles. Performance of the joints, ramp rate sensitivity, and stability against thermal or electromagnetic disturbances, electrical insulation, losses, and instrumentation are addressed separately and therefore are not major goals in this project. However, losses and joint performance will be tested during the CSI testing campaign. The USIPO will build the CSI that will be tested at the Central Solenoid Model Coil (CSMC) Test Facility at the Japan Atomic Energy Agency (JAEA), Naka, Japan. The industrial vendors (the Suppliers) will report to the USIPO (the Company). All approvals to proceed will be issued by the Company, which in some cases, as specified in this document, will also require the approval of the ITER Organization. Responsibilities and obligations will be covered by respective contracts between the USIPO, called Company interchangeably, and the industrial Prime Contractors, called Suppliers. Different stages of work may be performed by more than one Prime Contractor, as described in this specification. Technical requirements of the contract between the Company and the Prime Contractor will be covered by the Fabrication Specifications developed by the Prime Contractor based on this document and approved by

  17. Laser-heated solenoid fusion

    International Nuclear Information System (INIS)

    Vlases, G.C.

    1977-01-01

    Since the suggestion by Dawson, Hertzberg, and Kidder that high-energy CO 2 lasers could be used to heat magnetically confined plasma columns to thermonuclear temperatures, a great deal of theoretical and experimental work has been performed. In this paper we first review the experiments on the basic laser-plasma interaction phenomena, in which lasers with energies up to 1 kJ have been used to produce plasmas at n/sub e/ greater than 10 18 and T/sub e/ greater than 200 eV. The second part reviews fusion reactor studies based on the laser solenoid

  18. High field laser heated solenoids

    International Nuclear Information System (INIS)

    Hoffman, A.L.

    1979-01-01

    A 10 kJ pulsed CO 2 laser and 3.8 cm bore, 15 T, 8 μs rise time, 1-m long fast solenoid facility has been constructed to demonstrate the feasibility of using long wavelength lasers to heat magnetically confined plasmas. The most critical physics requirement is the necessity of creating and maintaining an on-axis electron density minimum to trap the axially directed laser beam. Satisfaction of this requirement has been demonstrated by heating 1.5 Torr deuterium fill plasmas in 2.7 cm bore plasma tubes to line energies of approximately 1 kJ/m. (Auth.)

  19. Bistable diverter valve in microfluidics

    Czech Academy of Sciences Publication Activity Database

    Tesař, Václav; Bandulasena, H.C.H.

    2011-01-01

    Roč. 50, č. 5 (2011), s. 1225-1233 ISSN 0723-4864 R&D Projects: GA ČR GA101/07/1499; GA AV ČR IAA200760705 Institutional research plan: CEZ:AV0Z20760514 Keywords : fluidics * bistable diverter valves * pressure-driven microfluidics Subject RIV: BK - Fluid Dynamics Impact factor: 1.735, year: 2011 http://www.springerlink.com/content/x4907p1908151522/

  20. Brain networks underlying bistable perception.

    Science.gov (United States)

    Baker, Daniel H; Karapanagiotidis, Theodoros; Coggan, David D; Wailes-Newson, Kirstie; Smallwood, Jonathan

    2015-10-01

    Bistable stimuli, such as the Necker Cube, demonstrate that experience can change in the absence of changes in the environment. Such phenomena can be used to assess stimulus-independent aspects of conscious experience. The current study used resting state functional magnetic resonance imaging (rs-fMRI) to index stimulus-independent changes in neural activity to understand the neural architecture that determines dominance durations during bistable perception (using binocular rivalry and Necker cube stimuli). Anterior regions of the Superior Parietal Lobule (SPL) exhibited robust connectivity with regions of primary sensorimotor cortex. The strength of this region's connectivity with the striatum predicted shorter dominance durations during binocular rivalry, whereas its connectivity to pre-motor cortex predicted longer dominance durations for the Necker Cube. Posterior regions of the SPL, on the other hand, were coupled to associative cortex in the temporal and frontal lobes. The posterior SPL's connectivity to the temporal lobe predicted longer dominance during binocular rivalry. In conjunction with prior work, these data suggest that the anterior SPL contributes to perceptual rivalry through the inhibition of incongruent bottom up information, whereas the posterior SPL influences rivalry by supporting the current interpretation of a bistable stimulus. Our data suggests that the functional connectivity of the SPL with regions of sensory, motor, and associative cortex allows it to regulate the interpretation of the environment that forms the focus of conscious attention at a specific moment in time. Copyright © 2015. Published by Elsevier Inc.

  1. Design of a 16 kbit superconducting latching/SFQ hybrid RAM

    International Nuclear Information System (INIS)

    Nagasawa, Shuichi; Hasegawa, Haruhiro; Hashimoto, Tatsunori; Suzuki, Hideo; Miyahara, Kazunori; Enomoto, Youichi

    1999-01-01

    We have designed a 16 kbit superconducting latching/SFQ hybrid (SLASH) RAM, which enables high-frequency clock operation up to 10 GHz. The 16 kbit SLASH RAM consists of four 4x4 matrix arrays of 256 bit RAM blocks, block decoders, latching block drivers, latching block senses, impedance matched lines and the powering circuits. The 256 bit RAM block is composed of a 16x16 matrix array of vortex transitional memory cells, latching drivers, SFQ NOR decoders and latching sense circuits. We have also designed and implemented an SFQ NOR decoder that is composed of magnetically coupled multi-input OR gates and RSFQ inverters. (author)

  2. CERN tests largest superconducting solenoid magnet

    CERN Multimedia

    2006-01-01

    "CERN's Compacts Muon Solenoid (CMS) - the world's largest superconducting solenoid magnet - has reached full field in testing. The instrument is part of the proton-proton Large Hadron Collider (LHC) project, located in a giant subterranean chamber at Cessy on the Franco-Swiss border." (1 page)

  3. A novel bistable energy harvesting concept

    International Nuclear Information System (INIS)

    Scarselli, G; Nicassio, F; Pinto, F; Ciampa, F; Iervolino, O; Meo, M

    2016-01-01

    Bistable energy harvesting has become a major field of research due to some unique features for converting mechanical energy into electrical power. When properly loaded, bistable structures snap-through from one stable configuration to another, causing large strains and consequently power generation. Moreover, bistable structures can harvest energy across a broad-frequency bandwidth due to their nonlinear characteristics. Despite the fact that snap-through may be triggered regardless of the form or frequency of exciting vibration, the external force must reach a specific snap-through activation threshold value to trigger the transition from one stable state to another. This aspect is a limiting factor for realistic vibration energy harvesting application with bistable devices. This paper presents a novel power harvesting concept for bistable composites based on a ‘lever effect’ aimed at minimising the activation force to cause the snap through by choosing properly the bistable structures’ constraints. The concept was demonstrated with the help of numerical simulation and experimental testing. The results showed that the actuation force is one order of magnitude smaller (3%–6%) than the activation force of conventionally constrained bistable devices. In addition, it was shown that the output voltage was higher than the conventional configuration, leading to a significant increase in power generation. This novel concept could lead to a new generation of more efficient bistable energy harvesters for realistic vibration environments. (paper)

  4. ATLAS's superconducting solenoid takes up position

    CERN Multimedia

    2004-01-01

    The ATLAS superconducting solenoid was moved to its final destination on 16 January. It has taken up position opposite the ATLAS liquid argon barrel cryostat, which will house the electromagnetic calorimeter. All that remains to do now is to slide it into the insulation vacuum, this will be done in the next few weeks. Built by Toshiba, under responsibility of KEK in Japan, the central solenoid is 2.4 metres in diameter, 5.3 metres long and weighs 5.5 tonnes. "It will provide an axial magnetic field of 2 Tesla that will deflect particles inside the inner detector," as Roger Ruber, on-site project coordinator, explains. The inner detector, which consists of three sub-detectors, will be installed inside the solenoid later. The solenoid during one of the transport operations. Securely attached to the overhead travelling crane, the solenoid is situated in front of the opening to the liquid argon calorimeter, it will be inserted soon.

  5. Diversity and functional properties of bistable pigments.

    Science.gov (United States)

    Tsukamoto, Hisao; Terakita, Akihisa

    2010-11-01

    Rhodopsin and related opsin-based pigments, which are photosensitive membrane proteins, have been extensively studied using a wide variety of techniques, with rhodopsin being the most understood G protein-coupled receptor (GPCR). Animals use various opsin-based pigments for vision and a wide variety of non-visual functions. Many functionally varied pigments are roughly divided into two kinds, based on their photoreaction: bistable and monostable pigments. Bistable pigments are thermally stable before and after photo-activation, but monostable pigments are stable only before activation. Here, we review the diversity of bistable pigments and their molecular characteristics. We also discuss the mechanisms underlying different molecular characteristics of bistable and monostable pigments. In addition, the potential of bistable pigments as a GPCR model is proposed.

  6. ''Massless gaps'' for solenoid + calorimeter

    International Nuclear Information System (INIS)

    Marraffino, J.; Wu, W.; Beretvas, A.; Green, D.; Denisenko, K.; Para, A.

    1991-11-01

    The necessary existence of material in front of the first active element in a calorimeter will degrade the performance of that device. The question is by what factor. The follow up question is what can be done to minimize the damage. These questions are usually of primary importance for liquid argon calorimetry because of the necessity of containment dewars. However, the problem is universal. For example, the Solenoid Detector Collaboration, SDC, has proposed a superconducting coil which would be placed in front of the EM calorimeter. Although much effort has been made to minimize the depth of material in the coil, still the resolution and linearity must be optimized if the SDC goal of precision electromagnetic (EM) calorimetry is to be realized

  7. Electron beam solenoid reactor concept

    International Nuclear Information System (INIS)

    Bailey, V.; Benford, J.; Cooper, R.; Dakin, D.; Ecker, B.; Lopez, O.; Putman, S.; Young, T.S.T.

    1977-01-01

    The electron Beam Heated Solenoid (EBHS) reactor is a linear magnetically confined fusion device in which the bulk or all of the heating is provided by a relativistic electron beam (REB). The high efficiency and established technology of the REB generator and the ability to vary the coupling length make this heating technique compatible with several radial and axial enery loss reduction options including multiple-mirrors, electrostatic and gas end-plug techniques. This paper addresses several of the fundamental technical issues and provides a current evaluation of the concept. The enhanced confinement of the high energy plasma ions due to nonadiabatic scattering in the multiple mirror geometry indicates the possibility of reactors of the 150 to 300 meter length operating at temperatures > 10 keV. A 275 meter EBHS reactor with a plasma Q of 11.3 requiring 33 MJ of beam eneergy is presented

  8. CDL, a Precise, Low-Cost Coincidence Detector Latch

    Directory of Open Access Journals (Sweden)

    Ralf Joost

    2015-12-01

    Full Text Available The electronic detection of the coincidence of two events is still a key ingredient for high-performance applications, such as Positron Emission Tomography and Quantum Optics. Such applications are demanding, since the precision of their calculations and thus their conclusions directly depend on the duration of the interval in which two events are considered coincidental. This paper proposes a new circuitry, called coincidence detector latch (CDL, which is derived from standard RS latches. The CDL has the following advantages: low complexity, fully synthesizable, and high scalability. Even in its simple implementation, it achieves a coincidence window width as short as 115 ps, which is more than 10 times better than that reported by recent research.

  9. Novel latch for adiabatic quantum-flux-parametron logic

    International Nuclear Information System (INIS)

    Takeuchi, Naoki; Yamanashi, Yuki; Yoshikawa, Nobuyuki; Ortlepp, Thomas

    2014-01-01

    We herein propose the quantum-flux-latch (QFL) as a novel latch for adiabatic quantum-flux-parametron (AQFP) logic. A QFL is very compact and compatible with AQFP logic gates and can be read out in one clock cycle. Simulation results revealed that the QFL operates at 5 GHz with wide parameter margins of more than ±22%. The calculated energy dissipation was only ∼0.1 aJ/bit, which yields a small energy delay product of 20 aJ·ps. We also designed shift registers using QFLs to demonstrate more complex circuits with QFLs. Finally, we experimentally demonstrated correct operations of the QFL and a 1-bit shift register (a D flip-flop)

  10. Indirectly cooled large thin superconducting CDF solenoid

    International Nuclear Information System (INIS)

    Kondo, Kunitaka; Mori, Shigeki; Yoshizaki, Ryozo; Saito, Ryusei; Asano, Katsuhiko.

    1985-01-01

    The manufacturing technique of the indirectly cooled large thin superconducting solenoid for the collider detector facility (CDF solenoid) has been studied through cooperation of University of Tsukuba and the National Laboratory for High Energy Physics of the Ministry of Education of Japan, and the Fermi National Accelerator Laboratory in the U.S. Fabrication and testing of the solenoid has recently been completed by Hitachi. The CDF solenoid has a large-sized thin structure for meeting the requirement by experiments to be applied. Hitachi has thus developed a variety of new technologies including the design standard, coil cooling method, material selection, and manufacturing technique in accordance with experimental data, which were confirmed in a series of analyses and tests made on various prototypes. The CDF solenoid, built using Hitachi's new technologies, is of the world's top class among equipment of this type. This paper outlines the design criteria for the major components employed in the CDF solenoid and the test results of the solenoid. (author)

  11. A broadband electromagnetic energy harvester with a coupled bistable structure

    OpenAIRE

    Zhu, Dibin; Beeby, Steve

    2013-01-01

    This paper investigates a broadband electromagnetic energy harvester with a coupled bistable structure. Both analytical model and experimental results showed that the coupled bistable structure requires lower excitation force to trigger bistable operation than conventional bistable structures. A compact electromagnetic vibration energy harvester with a coupled bistable structure was implemented and tested. It was excited under white noise vibrations. Experimental results showed that the coupl...

  12. Latch-up control in CMOS integrated circuits

    International Nuclear Information System (INIS)

    Ochoa, A.; Dawes, W.; Estreich, D.; Packard, H.

    1979-01-01

    The potential for latch-up, a pnpn self-sustaining low impedance state, is inherent in standard bulk CMOS-integrated circuit structures. Under normal bias, the parasitic SCR is in its blocking state but, if subjected to a large voltage spike or if exposed to an ionizing environment, triggering may occur. This may result in device burn-out or loss of state. The problem has been extensively studied for space and weapons applications. Prevention of latch-up has been achieved in conservative design (approx. 9 μm p-well depths) by the use of minority lifetime control methods such as gold doping and neutron irradiation and by modifying the base transport factor with buried layers. The push toward VLSI densities will enhance parasitic action sufficiently so that the problem will become of more universal concern. The paper will surveys latch-up control methods presently employed for weapons and space applications on present (approx. 9 μm p-well) CMOS and indicates the extent of their applicability to VLSI designs

  13. Designing focusing solenoids for superconducting RF accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Davis, G.; Kashikhin, V.V.; Page, T.; Terechkine, I.; Tompkins, J.; Wokas, T.; /Fermilab

    2006-08-01

    The design of a focusing solenoid for use in a superconducting RF linac requires resolving a range of problems with conflicting requirements. Providing the required focusing strength contradicts the goal of minimizing the stray field on the surfaces of adjacent superconducting RF cavities. The requirement of a compact solenoid, able to fit into a gap between cavities, contradicts the need of mechanical support necessary to restrain electromagnetic forces that can result in coil motion and subsequent quenching. In this report we will attempt to address these and other issues arising during the development of focusing solenoids. Some relevant test data will also be presented.

  14. Embedded Solenoid Transformer for Power Conversion

    DEFF Research Database (Denmark)

    2015-01-01

    A resonant power converter for operation in the radio frequency range, preferably in the VHF, comprises at least one PCB-embedded transformer. The transformer is configured for radio frequency operation and comprises a printed circuit board defining a horizontal plane, the printed circuit board...... comprising at least two horizontal conductive layers separated by an isolating layer, a first embedded solenoid forming a primary winding of the transformer and a second embedded solenoid being arranged parallel to the first solenoid and forming a secondary winding of the transformer, wherein the first...

  15. BRIEF COMMUNICATION: Electrothermal bistability tuning in a large displacement micro actuator

    Science.gov (United States)

    Gerson, Y.; Krylov, S.; Ilic, B.

    2010-11-01

    We report on an approach allowing simple yet efficient tuning of the bistability properties in large displacement micro actuators. The devices fabricated from silicon on insulator (SOI) wafers using a deep reactive ion etching (DRIE)-based process incorporate elastic suspension realized as a pair of beams initially curved in-plane and are operated electrostatically by a comb-drive transducer. The curvature of beam and therefore the stability characteristics of the suspension are controlled by passing a current through the suspension and resistive heating the beam material. Experimental results, which are in good agreement with the finite elements model predictions, demonstrate the feasibility of the suggested approach and show that the application of a small tuning current increases the device deflection from 42 to 56 µm, allows adjustment of the critical snap-through and snap-back voltages and makes it possible the control of latching without an additional electrode. The approach can be efficiently implemented in electrical and optical switches and threshold inertial and mass sensors where the use of long displacement actuators with an adjustable bistability range is beneficial.

  16. ITER Central Solenoid Module Fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Smith, John [General Atomics, San Diego, CA (United States)

    2016-09-23

    The fabrication of the modules for the ITER Central Solenoid (CS) has started in a dedicated production facility located in Poway, California, USA. The necessary tools have been designed, built, installed, and tested in the facility to enable the start of production. The current schedule has first module fabrication completed in 2017, followed by testing and subsequent shipment to ITER. The Central Solenoid is a key component of the ITER tokamak providing the inductive voltage to initiate and sustain the plasma current and to position and shape the plasma. The design of the CS has been a collaborative effort between the US ITER Project Office (US ITER), the international ITER Organization (IO) and General Atomics (GA). GA’s responsibility includes: completing the fabrication design, developing and qualifying the fabrication processes and tools, and then completing the fabrication of the seven 110 tonne CS modules. The modules will be shipped separately to the ITER site, and then stacked and aligned in the Assembly Hall prior to insertion in the core of the ITER tokamak. A dedicated facility in Poway, California, USA has been established by GA to complete the fabrication of the seven modules. Infrastructure improvements included thick reinforced concrete floors, a diesel generator for backup power, along with, cranes for moving the tooling within the facility. The fabrication process for a single module requires approximately 22 months followed by five months of testing, which includes preliminary electrical testing followed by high current (48.5 kA) tests at 4.7K. The production of the seven modules is completed in a parallel fashion through ten process stations. The process stations have been designed and built with most stations having completed testing and qualification for carrying out the required fabrication processes. The final qualification step for each process station is achieved by the successful production of a prototype coil. Fabrication of the first

  17. Transcriptional delay stabilizes bistable gene networks.

    Science.gov (United States)

    Gupta, Chinmaya; López, José Manuel; Ott, William; Josić, Krešimir; Bennett, Matthew R

    2013-08-02

    Transcriptional delay can significantly impact the dynamics of gene networks. Here we examine how such delay affects bistable systems. We investigate several stochastic models of bistable gene networks and find that increasing delay dramatically increases the mean residence times near stable states. To explain this, we introduce a non-Markovian, analytically tractable reduced model. The model shows that stabilization is the consequence of an increased number of failed transitions between stable states. Each of the bistable systems that we simulate behaves in this manner.

  18. Test results of the g-2 superconducting solenoid magnet system

    NARCIS (Netherlands)

    Bunce, G; Morse, WM; Benante, J; Cullen, MH; Danby, GT; Endo, K; Fedotovich, GV; Geller, J; Green, MA; Grossmann, A; GrossePerdckamp, M; Haeberlen, U; Hseuh, H; Hirabayashi, H; Hughes, VW; Jackson, JW; Jia, LX; Jungmann, K; Krienen, F; Larsen, R; Khazin, B; Kawall, D; Meng, W; Pai, C; Polk, T.; Prigl, R; Putlitz, GZ; Redin, S; Roberts, BL; Ryskulov, N; Semertzidas, Y; Shutt, R; Snydstrup, L; Tallerico, T; vonWalter, P; Woodle, K; Yamamoto, A

    The g-2 experiment dipole consists of a single 48 turn, 15.1 meter diameter outer solenoid and a pair of 24 turn inner solenoids, 13.4 meters in diameter. The inner solenoids are hooked in series and are run at a polarity that is opposite that of the outer solenoid, thus creating a dipole field in

  19. Form coefficient of helical toroidal solenoids

    International Nuclear Information System (INIS)

    Amelin, V.Z.; Kunchenko, V.B.

    1982-01-01

    For toroidal solenoids with continuous spiral coil, winded according to the laws of equiinclined and simple cylindrical spirals with homogeneous, linearly increasing to the coil periphery and ''Bitter'' distribution of current density, the analytical expressions for the dependence between capacity consumed and generated magnetic field, expressions for coefficients of form similar to Fabry coefficient for cylindrical solenoids are obtained and dependence of the form coefficient and relative volume of solenoid conductor on the number of revolutions of screw line per one circumvention over the large torus radius is also investigated. Analytical expressions of form coefficients and graphical material permit to select the optimum geometry as to capacity consumed both for spiral (including ''force-free'') and conventional toroidal solenoids of magnetic systems in thermonulear installations

  20. Ultimate Performance of the ATLAS Superconducting Solenoid

    CERN Document Server

    Ruber, R; Kawai, M; Kondo, Y; Doi, Y; Haruyama, T; Haug, F; Kate, H ten; Kondo, T; Pirotte, O; Metselaar, J; Mizumaki, S; Olesen, G; Sbrissa, E; Yamamoto, A

    2007-01-01

    A 2 tesla, 7730 ampere, 39 MJ, 45 mm thin superconducting solenoid with a 2.3 meters warm bore and 5.3 meters length, is installed in the center of the ATLAS detector and successfully commissioned. The solenoid shares its cryostat with one of the detector's calorimeters and provides the magnetic field required for the inner detectors to accurately track collision products from the LHC at CERN. After several years of a stepwise construction and test program, the solenoid integration 100 meters underground in the ATLAS cavern is completed. Following the on-surface acceptance test, the solenoid is now operated with its final cryogenic, powering and control system. A re-validation of all essential operating parameters is completed. The performance and test results of underground operation are reported and compared to those previously measured.

  1. Compact muon solenoid magnet reaches full field

    CERN Multimedia

    2006-01-01

    Scientist of the U.S. Department of Energy in Fermilab and collaborators of the US/CMS project announced that the world's largest superconducting solenoid magnet has reached full field in tests at CERN. (1 apge)

  2. HB+ inserted into the CMS Solenoid

    CERN Multimedia

    Tejinder S. Virdee, CERN

    2006-01-01

    The first half of the barrel hadron calorimeter (HB+) has been inserted into the superconducting solenoid of CMS, in preparation for the magnet test and cosmic challenge. The operation went smoothly, lasting a couple of days.

  3. Laser solenoid fusion--fission design

    International Nuclear Information System (INIS)

    Steinhauer, L.C.; Taussig, R.T.

    1976-01-01

    The dependence of breeding performance on system engineering parameters is examined for laser solenoid fusion-fission reactors. Reactor performance is found to be relatively insensitive to most of the engineering parameters, and compact designs can be built based on reasonable technologies. Point designs are described for the prototype series of reactors (mid-term technologies) and for second generation systems (advanced technologies). It is concluded that the laser solenoid has a good probability of timely application to fuel breeding needs

  4. Advances in laser solenoid fusion reactor design

    International Nuclear Information System (INIS)

    Steinhauer, L.C.; Quimby, D.C.

    1978-01-01

    The laser solenoid is an alternate fusion concept based on a laser-heated magnetically-confined plasma column. The reactor concept has evolved in several systems studies over the last five years. We describe recent advances in the plasma physics and technology of laser-plasma coupling. The technology advances include progress on first walls, inner magnet design, confinement module design, and reactor maintenance. We also describe a new generation of laser solenoid fusion and fusion-fission reactor designs

  5. Outcomes of Video-Assisted Teaching for Latching in Postpartum Women: A Randomized Controlled Trial.

    Science.gov (United States)

    Sroiwatana, Suttikamon; Puapornpong, Pawin

    2018-04-25

    Latching is an important process of breastfeeding and should be taught and practiced by the postpartum mother. The objective is to compare latching outcomes between video-assisted and routine teaching methods among postpartum women. A randomized controlled trial was conducted. Postpartum women who had deliveries without complications were randomized into two groups: 14 cases in the video-assisted teaching group and 14 cases in a routine teaching group. In the first group, the mothers were taught breastfeeding benefits, latching methods, and breastfeeding positions and practiced breastfeeding in a controlled setting for a 30-minute period and watched a 6-minute video with consistent content. In the second group, the mothers were taught a normal 30-minute period and then practiced breastfeeding. In both groups, Latching on, Audible swallowing, the Type of nipples, Comfort, and Help (LATCH) scores were assessed at 24-32 and 48-56 hours after the breastfeeding teaching modals. Demographic data and LATCH scores were collected and analyzed. There were no statistically significant differences in the mothers' ages, occupations, marital status, religion, education, income, infants' gestational age, body mass index, nipple length, route of delivery, and time to first latching between the video-assisted and routine breastfeeding teaching groups. First and second LATCH score assessments had shown no significant differences between both breastfeeding teaching groups. The video-assisted breastfeeding teaching did not improve latching outcomes when it was compared with routine teaching.

  6. Possible hysteresis loops of resonatorless optical bistability

    International Nuclear Information System (INIS)

    Nguyen Ba An; Le Thi Cat Tuong.

    1990-05-01

    We qualitatively show that hysteresis loops of intrinsic optical bistability phenomena without any additional feedback may be of various shapes including those of a butterfly and a three-winged bow. (author). 15 refs, 4 figs

  7. Space charge effects and electronic bistability

    International Nuclear Information System (INIS)

    Ruffini, A.; Strumia, F.; Tommasi, O.

    1996-01-01

    The excitation of metastable states in an atomic beam apparatus by means of electron collision is a widespread technique. The authors have observed a large bistable behaviour in apparatus designed to provide an intense and collimated beam of metastable helium by excitation with orthogonally impinging electrons. This bistable behaviour largely affects the efficiency of the apparatus and is therefore worth of being carefully investigated. The apparatus has an electrode configuration equivalent to that of a tetrode valve with large intergrid distances. The bistability consists in a hysteresis cycle in the curve of the anode current vs. grid voltage. Experimental measurements, supported by a simple theoretical model and by numerical simulation, stress out the crucial role played by space charge effects for the onset of bistability. A comparison with previous observations of this phenomenon is given. Spontaneous current oscillations with various shapes have been recorded in one of the two curves of the hysteresis cycle

  8. Bistable fluidic valve is electrically switched

    Science.gov (United States)

    Fiet, O.; Salvinski, R. J.

    1970-01-01

    Bistable control valve is selectively switched by direct application of an electrical field to divert fluid from one output channel to another. Valve is inexpensive, has no moving parts, and operates on fluids which are relatively poor electrical conductors.

  9. Origami Mechanics: Bistability and Isometries

    Science.gov (United States)

    Adda-Bedia, Mokhtar; Lechenault, Frederic; Morphogenesis; multiscale phenomena Team

    2015-03-01

    Origami structures are usually seen as assemblies of rigid faces articulated around creases with hinge-like behaviour. Their deployment and degrees of freedom are purely kinematic, resulting only from the geometry of the crease network. However, in real folded structures, the base material can deform outside the creases. In such situations, face bending competes with crease actuation in a morphogenetic way. In order to rationalise this interplay, we investigate the mechanical behaviour of an infinite sheet on which one or more straight creases meet at a single vertex. We find that these structures generically exhibit bistability, in the sense that they can snap through from one metastable configuration to another. Furthermore, we uncover a new class of isometry of the plane, which corresponds to metastable states of a creased sheet for which the hoop stress vanishes, an instability mechanism that is also responsible for the wrinkling of thin plates.

  10. GABA shapes the dynamics of bistable perception.

    Science.gov (United States)

    van Loon, Anouk M; Knapen, Tomas; Scholte, H Steven; St John-Saaltink, Elexa; Donner, Tobias H; Lamme, Victor A F

    2013-05-06

    Sometimes, perception fluctuates spontaneously between two distinct interpretations of a constant sensory input. These bistable perceptual phenomena provide a unique window into the neural mechanisms that create the contents of conscious perception. Models of bistable perception posit that mutual inhibition between stimulus-selective neural populations in visual cortex plays a key role in these spontaneous perceptual fluctuations. However, a direct link between neural inhibition and bistable perception has not yet been established experimentally. Here, we link perceptual dynamics in three distinct bistable visual illusions (binocular rivalry, motion-induced blindness, and structure from motion) to measurements of gamma-aminobutyric acid (GABA) concentrations in human visual cortex (as measured with magnetic resonance spectroscopy) and to pharmacological stimulation of the GABAA receptor by means of lorazepam. As predicted by a model of neural interactions underlying bistability, both higher GABA concentrations in visual cortex and lorazepam administration induced slower perceptual dynamics, as reflected in a reduced number of perceptual switches and a lengthening of percept durations. Thus, we show that GABA, the main inhibitory neurotransmitter, shapes the dynamics of bistable perception. These results pave the way for future studies into the competitive neural interactions across the visual cortical hierarchy that elicit conscious perception. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Experiments with a double solenoid system

    Energy Technology Data Exchange (ETDEWEB)

    Pampa Condori, R.; Lichtenthaeler Filho, R.; Faria, P.N. de; Lepine-Szily, A.; Mendes Junior, D.R.; Pires, K.C.C.; Assuncao, M.; Scarduelli, V.B.; Leistenschneider, E.; Morais, M.C.; Shorto, J.M.B.; Gasques, L. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica

    2012-07-01

    Full text: RIBRAS [1] is presently the only experimental equipment in South America capable of producing secondary beams of rare isotopes. It consists of two superconducting solenoids, installed in one of the beam lines of the 8 MV Pelletron Tandem accelerator of the University of Sao Paulo. The exotic nuclei are produced in the collision between the primary beam of the Pelletron Accelerator and the primary target. The secondary beam is selected by the in-flight technique and is usually contaminated with particles coming from scattering and reactions in the primary target such as {sup 7}Li, alpha and other light particles as protons, deuterons and tritons. Solenoids are selectors with large acceptance and the double solenoid system provides ways to improve the quality of the secondary beam by using a degrador in the midst of the two solenoids. The main contamination of the secondary beam comes from {sup 7}Li{sup 2+} particles coming from the primary beam. A degrador placed between the two solenoids is able to separate those particles from the {sup 6}He beam providing an additional charge exchange {sup 7}Li{sup 2+-→}3{sup +}. In addition, the differential energy loss in the degrador provides further selection of the light particles as protons, deuterons, tritons and and alpha particles by the second solenoid. Here we present the results of the first experiment performed at RIBRAS using both solenoids. A pure {sup 6}He beam was produced and the reaction {sup 6}He+p was measured using a thick CH{sub 2} target. 1. R. Lichtenthaeler et al., Eur. Phys. J. A 25,s01,733 (2005) and Nucl. Phys. News 15, 25 (2005). (author)

  12. Central Solenoid On-surface Test

    CERN Multimedia

    Ruber, R

    2004-01-01

    A full scale on-surface test of the central solenoid has been performed before its final installation in the ATLAS cavern starting in November. The successful integration of the central solenoid into the barrel cryostat, as reported in the March 2004 ATLAS eNews, was hardly finished when testing started. After a six-week period to cool down the LAr calorimeter, the solenoid underwent a similar procedure. Cooling it down to 4.6 Kelvin from room temperature took just over five and a half days. Cold and superconducting, it was time to validate the functionality of the control and safety systems. These systems were largely the same as the systems to be used in the final underground installation, and will be used not only for the solenoid and toroid magnets, but parts of it also for other LHC experiments. This solenoid test was the first occasion to test the system functionality in a real working environment. Several days were spent to fine tune the systems, especially the critical safety system, which turned out...

  13. Engineering Evaluation of International Low Impact Docking System Latch Hooks

    Science.gov (United States)

    Martinez, J.; Patin, R.; Figert, J.

    2013-01-01

    The international Low Impact Docking System (iLIDS) provides a structural arrangement that allows for visiting vehicles to dock with the International Space Station (ISS) (Fig 1). The iLIDS docking units are mechanically joined together by a series of active and passive latch hooks. In order to preserve docking capability at the existing Russian docking interfaces, the iLIDS latch hooks are required to conform to the existing Russian design. The latch hooks are classified as being fail-safe. Since the latch hooks are fail-safe, the hooks are not fracture critical and a fatigue based service life assessment will satisfy the structural integrity requirements. Constant amplitude fatigue testing to failure on four sets of active/passive iLIDS latch hooks was performed at load magnitudes of 10, 11, and 12 kips. Failure analysis of the hook fatigue failures identified multi-site fatigue initiation that was effectively centered about the hook mid-plane (consistent with the 3D model results). The fatigue crack initiation distribution implies that the fatigue damage accumulation effectively results in a very low aspect ratio surface crack (which can be simulated as thru-thickness crack). Fatigue damage progression resulted in numerous close proximity fatigue crack initiation sites. It was not possible to determine if fatigue crack coalescence occurs during cyclic loading or as result of the fast fracture response. The presence of multiple fatigue crack initiation sites on different planes will result in the formation of ratchet marks as the cracks coalesce. Once the stable fatigue crack becomes unstable and the fast fracture advances across the remaining ligament and the plane stress condition at a free-surface will result in failure along a 45 deg. shear plane (slant fracture) and the resulting inclined edge is called a shear lip. The hook thickness on the plane of fatigue crack initiation is 0.787". The distance between the shear lips on this plane was on the order of 0

  14. Field Mapping System for Solenoid Magnet

    Science.gov (United States)

    Park, K. H.; Jung, Y. K.; Kim, D. E.; Lee, H. G.; Park, S. J.; Chung, C. W.; Kang, B. K.

    2007-01-01

    A three-dimensional Hall probe mapping system for measuring the solenoid magnet of PLS photo-cathode RF e-gun has been developed. It can map the solenoid field either in Cartesian or in cylindrical coordinate system with a measurement reproducibility better than 5 × 10-5 T. The system has three axis motors: one for the azimuthal direction and the other two for the x and z direction. This architecture makes the measuring system simple in fabrication. The magnetic center was calculated using the measured axial component of magnetic field Bz in Cartesian coordinate system because the accuracy of magnetic axis measurement could be improved significantly by using Bz, instead of the radial component of magnetic field Br. This paper describes the measurement system and summarizes the measurement results for the solenoid magnetic of PLS photo-cathode RF e-gun.

  15. Hybrid optoelectronic device with multiple bistable outputs

    Energy Technology Data Exchange (ETDEWEB)

    Costazo-Caso, Pablo A; Jin Yiye; Gelh, Michael; Granieri, Sergio; Siahmakoun, Azad, E-mail: pcostanzo@ing.unlp.edu.are, E-mail: granieri@rose-hulma.edu, E-mail: siahmako@rose-hulma.edu [Department of Physics and Optical Engineering, Rose-Hulman Institute of Technology, 5500 Wabash Avenue, Terre Haute, IN 47803 (United States)

    2011-01-01

    Optoelectronic circuits which exhibit optical and electrical bistability with hysteresis behavior are proposed and experimentally demonstrated. The systems are based on semiconductor optical amplifiers (SOA), bipolar junction transistors (BJT), PIN photodiodes (PD) and laser diodes externally modulated with integrated electro-absorption modulators (LD-EAM). The device operates based on two independent phenomena leading to both electrical bistability and optical bistability. The electrical bistability is due to the series connection of two p-i-n structures (SOA, BJT, PD or LD) in reverse bias. The optical bistability is consequence of the quantum confined Stark effect (QCSE) in the multi-quantum well (MQW) structure in the intrinsic region of the device. This effect produces the optical modulation of the transmitted light through the SOA (or reflected from the PD). Finally, because the optical transmission of the SOA (in reverse bias) and the reflected light from the PD are so small, a LD-EAM modulated by the voltage across these devices are employed to obtain a higher output optical power. Experiments show that the maximum switching frequency is in MHz range and the rise/fall times lower than 1 us. The temporal response is mainly limited by the electrical capacitance of the devices and the parasitic inductances of the connecting wires. The effects of these components can be reduced in current integration technologies.

  16. Bubbling and bistability in two parameter discrete systems

    Indian Academy of Sciences (India)

    The birth of X *. · is concurrent with the ... for bistability viz. a½, and the higher order bistability points a¾, etc. are marked. The quadrilateral marked as ... The characteristics of 2 parameter 1-d maps that exhibit bubbling/bistability related to their ...

  17. Some options for the muon collider capture and decay solenoids

    International Nuclear Information System (INIS)

    Green, M.A.

    1995-11-01

    This report discusses some of the problems associated with using solenoid magnets to capture the secondary particles that are created when an intense beam of 8 to 10 GeV protons interacts with the target at the center of the capture region. Hybrid capture solenoids with inductions of 28 T and a 22T are described. The first 14 to 15 T of the solenoid induction will be generated by a superconducting magnet. The remainder of the field will be generated by a Bitter type of water cooled solenoid. The capture solenoids include a transition section from the high field solenoid to a 7 T decay channel where pions and kaons that come off of the target decay into muons. A short 7 T solenoidal decay channel between the capture solenoid system and the phase rotation system is described. A concept for separation of negative and positive pions and kaons is briefly discussed

  18. Perceptual incongruence influences bistability and cortical activation.

    Directory of Open Access Journals (Sweden)

    Gijs Joost Brouwer

    Full Text Available We employed a parametric psychophysical design in combination with functional imaging to examine the influence of metric changes in perceptual incongruence on perceptual alternation rates and cortical responses. Subjects viewed a bistable stimulus defined by incongruent depth cues; bistability resulted from incongruence between binocular disparity and monocular perspective cues that specify different slants (slant rivalry. Psychophysical results revealed that perceptual alternation rates were positively correlated with the degree of perceived incongruence. Functional imaging revealed systematic increases in activity that paralleled the psychophysical results within anterior intraparietal sulcus, prior to the onset of perceptual alternations. We suggest that this cortical activity predicts the frequency of subsequent alternations, implying a putative causal role for these areas in initiating bistable perception. In contrast, areas implicated in form and depth processing (LOC and V3A were sensitive to the degree of slant, but failed to show increases in activity when these cues were in conflict.

  19. Longitudinal magnetic bistability of electroplated wires

    International Nuclear Information System (INIS)

    Kurlyandskaya, G.V.; Garcia-Miquel, H.; Vazquez, M.; Svalov, A.V.; Vas'kovskiy, V.O.

    2002-01-01

    Fe 20 Ni 74 Co 6 and Fe 20 Ni 64 Co 16 1 μm thick magnetic tubes electroplated onto Cu 98 Be 2 conductive wire have been investigated in as-deposited state, after heat treatment under longitudinal magnetic field for 1 h at 330 deg. C, and after rf-sputtering deposition of the additional 2 μm Fe 19 Ni 81 layer. Heat treatments and an additional layer deposition modify the shape of hysteresis loops. Magnetically bistable behaviour, observed after the field annealing at a temperature of 330 deg. C, is studied as a function of the length of the samples. This is the first report by our knowledge on the bistable behaviour of the electroplated wires. The bistability of these wires is promising for applications such as tagging or pulse generator applications

  20. Balancing bistable perception during self-motion.

    Science.gov (United States)

    van Elk, Michiel; Blanke, Olaf

    2012-10-01

    In two experiments we investigated whether bistable visual perception is influenced by passive own body displacements due to vestibular stimulation. For this we passively rotated our participants around the vertical (yaw) axis while observing different rotating bistable stimuli (bodily or non-bodily) with different ambiguous motion directions. Based on previous work on multimodal effects on bistable perception, we hypothesized that vestibular stimulation should alter bistable perception and that the effects should differ for bodily versus non-bodily stimuli. In the first experiment, it was found that the rotation bias (i.e., the difference between the percentage of time that a CW or CCW rotation was perceived) was selectively modulated by vestibular stimulation: the perceived duration of the bodily stimuli was longer for the rotation direction congruent with the subject's own body rotation, whereas the opposite was true for the non-bodily stimulus (Necker cube). The results found in the second experiment extend the findings from the first experiment and show that these vestibular effects on bistable perception only occur when the axis of rotation of the bodily stimulus matches the axis of passive own body rotation. These findings indicate that the effect of vestibular stimulation on the rotation bias depends on the stimulus that is presented and the rotation axis of the stimulus. Although most studies on vestibular processing have traditionally focused on multisensory signal integration for posture, balance, and heading direction, the present data show that vestibular self-motion influences the perception of bistable bodily stimuli revealing the importance of vestibular mechanisms for visual consciousness.

  1. First Operation of the Central Solenoid

    CERN Multimedia

    Ruber, R.

    2006-01-01

    A new phase for the ATLAS collaboration started with the first operation of a completed sub-system: the Central Solenoid. It was cooled down from the 17th to 23th May 2006, and the first kA was put into it the same evening as it was cold and superconductive. That makes our solenoid the very first cold and superconducting magnet to be operated in the LHC underground areas. The Central Solenoid in its final position at the heart of ATLAS. The coil current (red line) and voltage (blue line) showing the operation at nominal current of 7.73 kA for a magnetic field of 2.0 T and the subsequent successful commissioning up to 8 kAT The cool down and powering of the solenoid was a major milestone for all control, cryogenic, power and vacuum systems and was achieved in perfect collaboration with the liquid argon detector with which it shares the Barrel Cryostat. Powering up to nominal current had to wait until the last week of July when the End-Cap Calorimeters were in closed position. The Tile Barrel and E...

  2. Compensation of oscillation coupling induced by solenoids

    International Nuclear Information System (INIS)

    Zelinskij, A.Yu.; Karnaukhov, I.M.; Shcherbakov, A.A.

    1988-01-01

    Methods for construction of various schemes of oscillation coupling compensation, induced by solenoids in charged particle storage rings, are described. Peculiarities of magnetic structure, enabling to localize oscillation coupling in wide energy range are discussed. Results of calculation of compensation schemes for design of NR-2000 storage ring spin rotation are presented

  3. Successful mapping of the solenoid magnet

    CERN Multimedia

    Aleksa, M.

    The ATLAS solenoid coil is about 5.3m long, has a diameter of 2.5m and is designed to deliver a magnetic field of approximately 2T for the ATLAS inner detector. The superconducting solenoid coil has been integrated inside the LAr barrel cryostat and was installed at its final position inside the cavern in November 2005. This summer - after completion of the extended barrel calorimeters and before the installation of the inner detector - the end cap calorimeters (LAr end caps and Tile extended barrels) were moved for the first time into their final position in order to create conditions as close as possible to final for the solenoid tests and for mapping the field inside the solenoid bore. Design and construction of the mapping machine The requirement on the absolute precision of the field measurements are 0.05% on the field integrals seen by particles; if this is achieved the momentum error coming from insufficient knowledge of the magnetic field will be negligible compared to the error stemming from the inn...

  4. Error field generation of solenoid magnets

    International Nuclear Information System (INIS)

    Saunders, J.L.

    1982-01-01

    Many applications for large solenoids and solenoidal arrays depend on the high precision of the axial field profile. In cases where requirements of ΔB/B for nonaxial fields are on the order of 10 -4 , the actual winding techniques of the solenoid need to be considered. Whereas an ideal solenoid consisting of current loops would generate no radial fields along the axis, in reality, the actual current-carrying conductors must follow spiral or helical paths. A straightforward method for determining the radial error fields generated by coils wound with actual techniques employed in magnet fabrication has been developed. The method devised uses a computer code which models a magnet by sending a single, current-carrying filament along the same path taken by the conductor during coil winding. Helical and spiral paths are simulated using small, straight-line current segments. This technique, whose results are presented in this paper, was used to predict radial field errors for the Elmo Bumpy Torus-Proof of Principle magnet. These results include effects due to various winding methods, not only spiral/helical and layer-to-layer transitions, but also the effects caused by worst-case tolerance conditions both from the conductor and the winding form (bobbin). Contributions made by extraneous circuitry (e.g., overhead buswork and incoming leads) are also mentioned

  5. Flowfield Analysis of a Pneumatic Solenoid Valve

    Directory of Open Access Journals (Sweden)

    Sheam-Chyun Lin

    2018-07-01

    Full Text Available Pneumatic solenoid valve has been widely used in the vehicle control systems for meeting the rapid-reaction demand triggered by the dynamic conditions encountered during the driving course of vehicle. For ensuring the safety of human being, the reliable and effective solenoid valve is in great demand to shorten the reaction time and thus becomes the topic of this research. This numerical study chooses a commercial 3/2-way solenoid valve as the reference valve for analysing its performance. At first, CFD software Fluent is adopted to simulate the flow field associated with the valve configuration. Then, the comprehensive flow visualization is implemented to identify the locations of adverse flow patterns. Accordingly, it is found that a high-pressure region exists in the zone between the nozzle exit and the top of iron core. Thereafter, the nozzle diameter and the distance between nozzle and spool are identified as the important design parameters for improving the pressure response characteristics of valve. In conclusion, this work establishes a rigorous and systematic CFD scheme to evaluate the performance of pneumatic solenoid valve.

  6. Growth techniques for monolithic YBCO solenoidal magnets

    International Nuclear Information System (INIS)

    Scruggs, S.J.; Putman, P.T.; Fang, H.; Alessandrini, M.; Salama, K.

    2006-01-01

    The possibility of growing large single domain YBCO solenoids by the use of a large seed has been investigated. There are two known methods for producing a similar solenoid. This first is a conventional top seeded melt growth process followed by a post processing machining step to create the bore. The second involves using multiple seeds spaced around the magnet bore. The appeal of the new technique lies in decreasing processing time compared to the single seed technique, while avoiding alignment problems found in the multiple seeding technique. By avoiding these problems, larger diameter monoliths can be produced. Large diameter monoliths are beneficial because the maximum magnetic field produced by a trapped field magnet is proportional to the radius of the sample. Furthermore, the availability of trapped field magnets with large diameter could enable their use in applications that traditionally have been considered to require wound electromagnets, such as beam bending magnets for particle accelerators or electric propulsion. A comparison of YBCO solenoids grown by the use of a large seed and grown by the use of two small seeds simulating multiple seeding is made. Trapped field measurements as well as microstructure evaluation were used in characterization of each solenoid. Results indicate that high quality growth occurs only in the vicinity of the seeds for the multiple seeded sample, while the sample with the large seeded exhibited high quality growth throughout the entire sample

  7. Growth techniques for monolithic YBCO solenoidal magnets

    Energy Technology Data Exchange (ETDEWEB)

    Scruggs, S.J. [Texas Center for Superconductivity at University of Houston, 4800 Calhoun, Houston, TX 77204 (United States)]. E-mail: Sscruggs2@uh.edu; Putman, P.T. [Texas Center for Superconductivity at University of Houston, 4800 Calhoun, Houston, TX 77204 (United States); Fang, H. [Texas Center for Superconductivity at University of Houston, 4800 Calhoun, Houston, TX 77204 (United States); Alessandrini, M. [Texas Center for Superconductivity at University of Houston, 4800 Calhoun, Houston, TX 77204 (United States); Salama, K. [Texas Center for Superconductivity at University of Houston, 4800 Calhoun, Houston, TX 77204 (United States)

    2006-10-01

    The possibility of growing large single domain YBCO solenoids by the use of a large seed has been investigated. There are two known methods for producing a similar solenoid. This first is a conventional top seeded melt growth process followed by a post processing machining step to create the bore. The second involves using multiple seeds spaced around the magnet bore. The appeal of the new technique lies in decreasing processing time compared to the single seed technique, while avoiding alignment problems found in the multiple seeding technique. By avoiding these problems, larger diameter monoliths can be produced. Large diameter monoliths are beneficial because the maximum magnetic field produced by a trapped field magnet is proportional to the radius of the sample. Furthermore, the availability of trapped field magnets with large diameter could enable their use in applications that traditionally have been considered to require wound electromagnets, such as beam bending magnets for particle accelerators or electric propulsion. A comparison of YBCO solenoids grown by the use of a large seed and grown by the use of two small seeds simulating multiple seeding is made. Trapped field measurements as well as microstructure evaluation were used in characterization of each solenoid. Results indicate that high quality growth occurs only in the vicinity of the seeds for the multiple seeded sample, while the sample with the large seeded exhibited high quality growth throughout the entire sample.

  8. Bistable Microvalve For Use With Microcatheter System

    Science.gov (United States)

    Seward, Kirk Patrick

    2003-12-16

    A bistable microvalve of shape memory material is operatively connected to a microcatheter. The bistable microvalve includes a tip that can be closed off until it is in the desired position. Once it is in position it can be opened and closed. The system uses heat and pressure to open and close the microvalve. The shape memory material will change stiffness and shape when heated above a transition temperature. The shape memory material is adapted to move from a first shape to a second shape, either open or closed, where it can perform a desired function.

  9. Unidirectional Transition Waves in Bistable Lattices.

    Science.gov (United States)

    Nadkarni, Neel; Arrieta, Andres F; Chong, Christopher; Kochmann, Dennis M; Daraio, Chiara

    2016-06-17

    We present a model system for strongly nonlinear transition waves generated in a periodic lattice of bistable members connected by magnetic links. The asymmetry of the on-site energy wells created by the bistable members produces a mechanical diode that supports only unidirectional transition wave propagation with constant wave velocity. We theoretically justify the cause of the unidirectionality of the transition wave and confirm these predictions by experiments and simulations. We further identify how the wave velocity and profile are uniquely linked to the double-well energy landscape, which serves as a blueprint for transition wave control.

  10. Bistable Topological Insulator with Exciton-Polaritons

    Science.gov (United States)

    Kartashov, Yaroslav V.; Skryabin, Dmitry V.

    2017-12-01

    The functionality of many nonlinear and quantum optical devices relies on the effect of optical bistability. Using microcavity exciton-polaritons in a honeycomb arrangement of microcavity pillars, we report the resonance response and bistability of topological edge states. A balance between the pump, loss, and nonlinearity ensures a broad range of dynamical stability and controls the distribution of power between counterpropagating states on the opposite edges of the honeycomb lattice stripe. Tuning energy and polarization of the pump photons, while keeping their momentum constant, we demonstrate control of the propagation direction of the dominant edge state. Our results facilitate the development of practical applications of topological photonics.

  11. Optimized Latching Control of Floating Point Absorber Wave Energy Converter

    Science.gov (United States)

    Gadodia, Chaitanya; Shandilya, Shubham; Bansal, Hari Om

    2018-03-01

    There is an increasing demand for energy in today’s world. Currently main energy resources are fossil fuels, which will eventually drain out, also the emissions produced from them contribute to global warming. For a sustainable future, these fossil fuels should be replaced with renewable and green energy sources. Sea waves are a gigantic and undiscovered vitality asset. The potential for extricating energy from waves is extensive. To trap this energy, wave energy converters (WEC) are needed. There is a need for increasing the energy output and decreasing the cost requirement of these existing WECs. This paper presents a method which uses prediction as a part of the control scheme to increase the energy efficiency of the floating-point absorber WECs. Kalman Filter is used for estimation, coupled with latching control in regular as well as irregular sea waves. Modelling and Simulation results for the same are also included.

  12. Bistable firing properties of soleus motor units in unrestrained rats

    DEFF Research Database (Denmark)

    EKEN, T.; KIEHN, O.

    1989-01-01

    of the motoneuron pool by stimulation of la afferents, or inhibition by stimulation of skin afferents. The shifts were not related to gross limb movements. This phenomenon is referred to as a bistable firing pattern. Bistable firing also occurred spontaneously during quiet standing. Typically the firing frequency...... was unchanged or only phasically influenced. These results demonstrate for the first time a bistable firing pattern during postural activity in the intact animal. The firing pattern closely resembles the bistable behaviour described in spinal motoneurons in reduced preparations, where it is due to the presence...... of a plateau potential. This suggests that the bistable firing is unexplained by plateau potentials also in the intact animal....

  13. First experiment with the double solenoid RIBRAS system

    Energy Technology Data Exchange (ETDEWEB)

    Lichtenthaeler, R.; Condori, R. Pampa; Lepine-Szily, A.; Pires, K. C. C.; Morais, M. C.; Leistenschneider, E.; Scarduelli, V. B.; Gasques, L. R. [Instituto de Fisica da USP, Sao Paulo, Brazil, C.P. 66318, 05314-970 (Brazil); Faria, P. N. de; Mendes, D. R. Jr. [Instituto de Fisica, Universidade Federal Fluminense, Niteroi, RJ, 24210-340 (Brazil); Shorto, J. M. B. [Instituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN, Av. Lineu Prestes, 2242, 05508-000, Sao Paulo, SP (Brazil); Assuncao, M. [Departamento de Ciencias Exatas e da Terra, Universidade Federal de Sao Paulo, Campus Diadema, Sao Paulo (Brazil)

    2013-05-06

    A description of the double solenoid system (RIBRAS) operating since 2004 in one of the beam lines of the Pelletron Laboratory of the Institute of Physics of the University of Sao Paulo is presented. The recent installation of the secondary scattering chamber after the second solenoid is reported and the first experiment in RIBRAS using both solenoids is described.

  14. Neuromechanistic Model of Auditory Bistability.

    Directory of Open Access Journals (Sweden)

    James Rankin

    2015-11-01

    Full Text Available Sequences of higher frequency A and lower frequency B tones repeating in an ABA- triplet pattern are widely used to study auditory streaming. One may experience either an integrated percept, a single ABA-ABA- stream, or a segregated percept, separate but simultaneous streams A-A-A-A- and -B---B--. During minutes-long presentations, subjects may report irregular alternations between these interpretations. We combine neuromechanistic modeling and psychoacoustic experiments to study these persistent alternations and to characterize the effects of manipulating stimulus parameters. Unlike many phenomenological models with abstract, percept-specific competition and fixed inputs, our network model comprises neuronal units with sensory feature dependent inputs that mimic the pulsatile-like A1 responses to tones in the ABA- triplets. It embodies a neuronal computation for percept competition thought to occur beyond primary auditory cortex (A1. Mutual inhibition, adaptation and noise are implemented. We include slow NDMA recurrent excitation for local temporal memory that enables linkage across sound gaps from one triplet to the next. Percepts in our model are identified in the firing patterns of the neuronal units. We predict with the model that manipulations of the frequency difference between tones A and B should affect the dominance durations of the stronger percept, the one dominant a larger fraction of time, more than those of the weaker percept-a property that has been previously established and generalized across several visual bistable paradigms. We confirm the qualitative prediction with our psychoacoustic experiments and use the behavioral data to further constrain and improve the model, achieving quantitative agreement between experimental and modeling results. Our work and model provide a platform that can be extended to consider other stimulus conditions, including the effects of context and volition.

  15. Total dose induced latch in short channel NMOS/SOI transistors

    International Nuclear Information System (INIS)

    Ferlet-Cavrois, V.; Quoizola, S.; Musseau, O.; Flament, O.; Leray, J.L.; Pelloie, J.L.; Raynaud, C.; Faynot, O.

    1998-01-01

    A latch effect induced by total dose irradiation is observed in short channel SOI transistors. This effect appears on NMOS transistors with either a fully or a partially depleted structure. It is characterized by a hysteresis behavior of the Id-Vg characteristics at high drain bias for a given critical dose. Above this dose, the authors still observe a limited leakage current at low drain bias (0.1 V), but a high conduction current at high drain bias (2 V) as the transistor should be in the off-state. The critical dose above which the latch appears strongly depends on gate length, transistor structure (fully or partially depleted), buried oxide thickness and supply voltage. Two-dimensional (2D) numerical simulations indicate that the parasitic condition is due to the latch of the back gate transistor triggered by charge trapping in the buried oxide. To avoid the latch induced by the floating body effect, different techniques can be used: doping engineering, body contacts, etc. The study of the main parameters influencing the latch (gate length, supply voltage) shows that the scaling of technologies does not necessarily imply an increased latch sensitivity. Some technological parameters like the buried oxide hardness and thickness can be used to avoid latch, even at high cumulated dose, on highly integrated SOI technologies

  16. Bent solenoids for spectrometers and emittance exchange sections

    International Nuclear Information System (INIS)

    Norem, J.

    1999-01-01

    Bent solenoids can be used to transport low energy beams as they provide both confinement and dispersion of particle orbits. Solenoids are being considered both as emittance exchange sections and spectrometers in the muon cooling system as part of the study of the muon collider. They present the results of a study of bent solenoids which considers the design of coupling sections between bent solenoids to straight solenoids, drift compensation fields, aberrations, and factors relating to the construction, such as field ripple, stored energy, coil forces and field errors

  17. Reference Design of the Mu2e Detector Solenoid

    CERN Document Server

    Feher, S; Brandt,, J; Cheban, S; Coleman, R; Dhanaraj, N; Fang, I; Lamm, M; Lombardo, V; Lopes, M; Miller, J; Ostojic, R ,; Orris, D; Page, T; Peterson, T; Tang, Z; Wands, R

    2014-01-01

    The Mu2e experiment at Fermilab has been approved by the Department of Energy to proceed developing the preliminary design. Integral to the success of Mu2e is the superconducting solenoid system. One of the three major solenoids is the Detector Solenoid that houses the stopping target and the detectors. The goal of the Detector Solenoid team is to produce detailed design specifications that are sufficient for vendors to produce the final design drawings, tooling and fabrication procedures and proceed to production. In this paper we summarize the Reference Design of the Detector Solenoid.

  18. Comparative performance analysis of a dual-solenoid mechanical oscillator

    International Nuclear Information System (INIS)

    Lee, V C C; Lee, H V; Harno, H G; Woo, K C

    2015-01-01

    An innovative dual-solenoid electro-mechanical-vibro-impact system has been constructed and experimentally studied. Comparative studies against a mechanical spring system and a permanent magnet system have been performed, where it is shown that the dual-solenoid system is able to produce oscillations better than the permanent magnet system and more energy efficiently. Comparison with a higher-powered dual solenoid system has also been conducted where a stationary solenoid has shown to be a more dominant parameter. In addition, it is also discovered that a mechanical oscillator in the dual-solenoid system is independent of the angular frequency. (paper)

  19. Form factor of some types of toroidal solenoids

    International Nuclear Information System (INIS)

    Koryavko, V.I.; Litvinenko, Yu.A.

    1979-01-01

    Obtained were the type of dependence between consumed power and formed field for toroidal helical-wound solenoids and the expression for the form factor analogous to the Fabry coefficient for cylindrical solenoids. Determined were optimum dimensions of the helical winding of ''forceless'' toroidal solenoids satisfying the condition of the formation of maximum field at minimum consumed power. Investigations also covered some types of conventional toroidal solenoids. Presented in the paper diagrams permitted to chose dimensions of the considered toroidal solenoids according to their consumed power and winding material volume

  20. Metastable and bistable defects in silicon

    International Nuclear Information System (INIS)

    Mukashev, Bulat N; Abdullin, Kh A; Gorelkinskii, Yurii V

    2000-01-01

    Existing data on the properties and structure of metastable and bistable defects in silicon are analyzed. Primary radiation-induced defects (vacancies, self-interstitial atoms, and Frenkel pairs), complexes of oxygen, carbon, hydrogen, and other impurity atoms and defects with negative correlation energy are considered. (reviews of topical problems)

  1. Organic bistable light-emitting devices

    Science.gov (United States)

    Ma, Liping; Liu, Jie; Pyo, Seungmoon; Yang, Yang

    2002-01-01

    An organic bistable device, with a unique trilayer structure consisting of organic/metal/organic sandwiched between two outmost metal electrodes, has been invented. [Y. Yang, L. P. Ma, and J. Liu, U.S. Patent Pending, U.S. 01/17206 (2001)]. When the device is biased with voltages beyond a critical value (for example 3 V), the device suddenly switches from a high-impedance state to a low-impedance state, with a difference in injection current of more than 6 orders of magnitude. When the device is switched to the low-impedance state, it remains in that state even when the power is off. (This is called "nonvolatile" phenomenon in memory devices.) The high-impedance state can be recovered by applying a reverse bias; therefore, this bistable device is ideal for memory applications. In order to increase the data read-out rate of this type of memory device, a regular polymer light-emitting diode has been integrated with the organic bistable device, such that it can be read out optically. These features make the organic bistable light-emitting device a promising candidate for several applications, such as digital memories, opto-electronic books, and recordable papers.

  2. A CW Gunn diode bistable switching element.

    Science.gov (United States)

    Hurtado, M.; Rosenbaum, F. J.

    1972-01-01

    Experiments with a current-controlled bistable switching element using a CW Gunn diode are reported. Switching rates of the order of 10 MHz have been obtained. Switching is initiated by current pulses of short duration (5-10 ns). Rise times of the order of several nanoseconds could be obtained.

  3. A bistable model of cell polarity.

    Directory of Open Access Journals (Sweden)

    Matteo Semplice

    Full Text Available Ultrasensitivity, as described by Goldbeter and Koshland, has been considered for a long time as a way to realize bistable switches in biological systems. It is not as well recognized that when ultrasensitivity and reinforcing feedback loops are present in a spatially distributed system such as the cell plasmamembrane, they may induce bistability and spatial separation of the system into distinct signaling phases. Here we suggest that bistability of ultrasensitive signaling pathways in a diffusive environment provides a basic mechanism to realize cell membrane polarity. Cell membrane polarization is a fundamental process implicated in several basic biological phenomena, such as differentiation, proliferation, migration and morphogenesis of unicellular and multicellular organisms. We describe a simple, solvable model of cell membrane polarization based on the coupling of membrane diffusion with bistable enzymatic dynamics. The model can reproduce a broad range of symmetry-breaking events, such as those observed in eukaryotic directional sensing, the apico-basal polarization of epithelium cells, the polarization of budding and mating yeast, and the formation of Ras nanoclusters in several cell types.

  4. Triggered Snap-Through of Bistable Shells

    Science.gov (United States)

    Cai, Yijie; Huang, Shicheng; Trase, Ian; Hu, Nan; Chen, Zi

    Elastic bistable shells are common structures in nature and engineering, such as the lobes of the Venus flytrap or the surface of a toy jumping poppers. Despite their ubiquity, the parameters that control the bistability of such structures are not well understood. In this study, we explore how the geometrical features of radially symmetric elastic shells affect the shape and potential energy of a shell's stable states, and how to tune certain parameters in order to generate a snap-through transition from a convex semi-stable state to concave stable state. We fabricated a series of elastic shells with varying geometric parameters out of silicone rubber and measured the resulting potential energy in the semi-stable state. Finite element simulations were also conducted in order to determine the deformation and stress in the shells during snap-through. It was found that the energy of the semi-stable state is controlled by only two geometric parameters and a dimensionless ratio. We also noted two distinct transitions during snap-through, one between monostability and semi-bistability (the state a popper toy is in before it snaps-through and jumps), and a second transition between semi-bistability and true bistability. This work shows that it is possible to use a set of simple parameters to tailor the energy landscape of an elastic shell in order to generate complex trigger motions for their potential use in smart applications. Z.C. acknowledge support from Society in Science-Branco Weiss Fellowship, administered by ETH Zurich.

  5. Non-Pyrotechnic Latch and Release System for Aerospace and Other Applications, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — American remote Vision Company (ARVC) will continue to research and develop a new non-pryotechnic latch and release sytem for use in servicing and flight release...

  6. SUPERCONDUCTING SOLENOIDS FOR THE MUON COLLIDER

    Energy Technology Data Exchange (ETDEWEB)

    GREEN,M.A.; EYSSA,Y.; KENNY,S.; MILLER,J.R.; PRESTEMON,S.; WEGGEL,R.J.

    2000-06-12

    The muon collider is a new idea for lepton colliders. The ultimate energy of an electron ring is limited by synchrotron radiation. Muons, which have a rest mass that is 200 times that of an electron can be stored at much higher energies before synchrotron radiation limits ring performance. The problem with muons is their short life time (2.1 {micro}s at rest). In order to operate a muon storage ring large numbers of muon must be collected, cooled and accelerated before they decay to an electron and two neutrinos. As the authors see it now, high field superconducting solenoids are an integral part of a muon collider muon production and cooling systems. This report describes the design parameters for superconducting and hybrid solenoids that are used for pion production and collection, RF phase rotations of the pions as they decay into muons and the muon cooling (reduction of the muon emittance) before acceleration.

  7. ATLAS superconducting solenoid on-surface test

    CERN Document Server

    Ruber, Roger J M Y; Doi, Y; Haruyama, T; Haug, F; ten Kate, H H J; Kawai, M; Kondo, T; Kondo, Y; Makida, Y; Mizumaki, S; Olesen, G; Pavlov, O V; Pezzetti, M; Pirotte, O; Sbrissa, E; Yamamoto, A

    2005-01-01

    The ATLAS detector is presently under construction as one of the five LHC experiment set-ups. It relies on a sophisticated magnet system for the momentum measurement of charged particle tracks. The superconducting solenoid is at the center of the detector, the magnet system part nearest to the proton-proton collision point. It is designed for a 2 Tesla strong axial magnetic field at the collision point, while its thin-walled construction of 0.66 radiation lengths avoids degradation of energy measurements in the outer calorimeters. The solenoid and calorimeter have been integrated in their common cryostat, cooled down and tested on-surface. We review the on-surface set-up and report the performance test results.

  8. Laser ion source with solenoid field

    International Nuclear Information System (INIS)

    Kanesue, Takeshi; Okamura, Masahiro; Fuwa, Yasuhiro; Kondo, Kotaro

    2014-01-01

    Pulse length extension of highly charged ion beam generated from a laser ion source is experimentally demonstrated. The laser ion source (LIS) has been recognized as one of the most powerful heavy ion source. However, it was difficult to provide long pulse beams. By applying a solenoid field (90 mT, 1 m) at plasma drifting section, a pulse length of carbon ion beam reached 3.2 μs which was 4.4 times longer than the width from a conventional LIS. The particle number of carbon ions accelerated by a radio frequency quadrupole linear accelerator was 1.2 × 10 11 , which was provided by a single 1 J Nd-YAG laser shot. A laser ion source with solenoid field could be used in a next generation heavy ion accelerator

  9. Laser ion source with solenoid field

    Energy Technology Data Exchange (ETDEWEB)

    Kanesue, Takeshi, E-mail: tkanesue@bnl.gov; Okamura, Masahiro [Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); Fuwa, Yasuhiro [Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo, Kyoto 606-7501 (Japan); RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Kondo, Kotaro [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo 152-8550 (Japan)

    2014-11-10

    Pulse length extension of highly charged ion beam generated from a laser ion source is experimentally demonstrated. The laser ion source (LIS) has been recognized as one of the most powerful heavy ion source. However, it was difficult to provide long pulse beams. By applying a solenoid field (90 mT, 1 m) at plasma drifting section, a pulse length of carbon ion beam reached 3.2 μs which was 4.4 times longer than the width from a conventional LIS. The particle number of carbon ions accelerated by a radio frequency quadrupole linear accelerator was 1.2 × 10{sup 11}, which was provided by a single 1 J Nd-YAG laser shot. A laser ion source with solenoid field could be used in a next generation heavy ion accelerator.

  10. Laser ion source with solenoid field

    Science.gov (United States)

    Kanesue, Takeshi; Fuwa, Yasuhiro; Kondo, Kotaro; Okamura, Masahiro

    2014-11-01

    Pulse length extension of highly charged ion beam generated from a laser ion source is experimentally demonstrated. The laser ion source (LIS) has been recognized as one of the most powerful heavy ion source. However, it was difficult to provide long pulse beams. By applying a solenoid field (90 mT, 1 m) at plasma drifting section, a pulse length of carbon ion beam reached 3.2 μs which was 4.4 times longer than the width from a conventional LIS. The particle number of carbon ions accelerated by a radio frequency quadrupole linear accelerator was 1.2 × 1011, which was provided by a single 1 J Nd-YAG laser shot. A laser ion source with solenoid field could be used in a next generation heavy ion accelerator.

  11. Cross section of the CMS solenoid

    CERN Multimedia

    Tejinder S. Virdee, CERN

    2005-01-01

    The pictures show a cross section of the CMS solenoid. One can see four layers of the superconducting coil, each of which contains the superconductor (central part, copper coloured - niobium-titanium strands in a copper coating, made into a "Rutherford cable"), surrounded by an ultra-pure aluminium as a magnetic stabilizer, then an aluminium alloy as a mechanical stabilizer. Besides the four layers there is an aluminium mechanical piece that includes pipes that transport the liquid helium.

  12. Robust mitotic entry is ensured by a latching switch

    Directory of Open Access Journals (Sweden)

    Chloe Tuck

    2013-07-01

    Cell cycle events are driven by Cyclin dependent kinases (CDKs and by their counter-acting phosphatases. Activation of the Cdk1:Cyclin B complex during mitotic entry is controlled by the Wee1/Myt1 inhibitory kinases and by Cdc25 activatory phosphatase, which are themselves regulated by Cdk1:Cyclin B within two positive circuits. Impairing these two feedbacks with chemical inhibitors induces a transient entry into M phase referred to as mitotic collapse. The pathology of mitotic collapse reveals that the positive circuits play a significant role in maintaining the M phase state. To better understand the function of these feedback loops during G2/M transition, we propose a simple model for mitotic entry in mammalian cells including spatial control over Greatwall kinase phosphorylation. After parameter calibration, the model is able to recapture the complex and non-intuitive molecular dynamics reported by Potapova et al. (Potapova et al., 2011. Moreover, it predicts the temporal patterns of other mitotic regulators which have not yet been experimentally tested and suggests a general design principle of cell cycle control: latching switches buffer the cellular stresses which accompany cell cycle processes to ensure that the transitions are smooth and robust.

  13. Robust mitotic entry is ensured by a latching switch.

    Science.gov (United States)

    Tuck, Chloe; Zhang, Tongli; Potapova, Tamara; Malumbres, Marcos; Novák, Béla

    2013-01-01

    Cell cycle events are driven by Cyclin dependent kinases (CDKs) and by their counter-acting phosphatases. Activation of the Cdk1:Cyclin B complex during mitotic entry is controlled by the Wee1/Myt1 inhibitory kinases and by Cdc25 activatory phosphatase, which are themselves regulated by Cdk1:Cyclin B within two positive circuits. Impairing these two feedbacks with chemical inhibitors induces a transient entry into M phase referred to as mitotic collapse. The pathology of mitotic collapse reveals that the positive circuits play a significant role in maintaining the M phase state. To better understand the function of these feedback loops during G2/M transition, we propose a simple model for mitotic entry in mammalian cells including spatial control over Greatwall kinase phosphorylation. After parameter calibration, the model is able to recapture the complex and non-intuitive molecular dynamics reported by Potapova et al. (Potapova et al., 2011). Moreover, it predicts the temporal patterns of other mitotic regulators which have not yet been experimentally tested and suggests a general design principle of cell cycle control: latching switches buffer the cellular stresses which accompany cell cycle processes to ensure that the transitions are smooth and robust.

  14. Bistable scattering in graphene-coated dielectric nanowires.

    Science.gov (United States)

    Li, Rujiang; Wang, Huaping; Zheng, Bin; Dehdashti, Shahram; Li, Erping; Chen, Hongsheng

    2017-06-22

    In nonlinear plasmonics, the switching threshold of optical bistability is limited by the weak nonlinear responses from the conventional Kerr dielectric media. Considering the giant nonlinear susceptibility of graphene, here we develop a nonlinear scattering model under the mean field approximation and study the bistable scattering in graphene-coated dielectric nanowires based on the semi-analytical solutions. We find that the switching intensities of bistable scattering can be smaller than 1 MW cm -2 at the working frequency. To further decrease the switching intensities, we show that the most important factor that restricts the bistable scattering is the relaxation time of graphene. Our work not only reveals some general characteristics of graphene-based bistable scattering, but also provides a guidance to further applications of optical bistability in the high speed all-optical signal processing.

  15. Bistable perception modeled as competing stochastic integrations at two levels.

    Science.gov (United States)

    Gigante, Guido; Mattia, Maurizio; Braun, Jochen; Del Giudice, Paolo

    2009-07-01

    We propose a novel explanation for bistable perception, namely, the collective dynamics of multiple neural populations that are individually meta-stable. Distributed representations of sensory input and of perceptual state build gradually through noise-driven transitions in these populations, until the competition between alternative representations is resolved by a threshold mechanism. The perpetual repetition of this collective race to threshold renders perception bistable. This collective dynamics - which is largely uncoupled from the time-scales that govern individual populations or neurons - explains many hitherto puzzling observations about bistable perception: the wide range of mean alternation rates exhibited by bistable phenomena, the consistent variability of successive dominance periods, and the stabilizing effect of past perceptual states. It also predicts a number of previously unsuspected relationships between observable quantities characterizing bistable perception. We conclude that bistable perception reflects the collective nature of neural decision making rather than properties of individual populations or neurons.

  16. Optical bistability and multistability in polaritonic materials doped with nanoparticles

    International Nuclear Information System (INIS)

    Wang, Zhiping; Yu, Benli

    2014-01-01

    We investigate the optical bistability and multistability in polaritonic materials doped with nanoparticles inside an optical ring cavity. It is found that the optical bistability and multistability can be easily controlled by adjusting the corresponding parameters of the system properly. The effect of the dipole–dipole interaction has also been included in the formulation, which leads to interesting phenomena. Our scheme opens up the possibility of controling the optical bistability and multistability in polaritonic materials doped with nanoparticles. (letter)

  17. Durable bistable auxetics made of rigid solids

    Science.gov (United States)

    Shang, Xiao; Liu, Lu; Rafsanjani, Ahmad; Pasini, Damiano

    2018-02-01

    Bistable Auxetic Metamaterials (BAMs) are a class of monolithic perforated periodic structures with negative Poisson's ratio. Under tension, a BAM can expand and reach a second state of equilibrium through a globally large shape transformation that is ensured by the flexibility of its elastomeric base material. However, if made from a rigid polymer, or metal, BAM ceases to function due to the inevitable rupture of its ligaments. The goal of this work is to extend the unique functionality of the original kirigami architecture of BAM to a rigid solid base material. We use experiments and numerical simulations to assess performance, bistability and durability of rigid BAMs at 10,000 cycles. Geometric maps are presented to elucidate the role of the main descriptors of BAM architecture. The proposed design enables the realization of BAM from a large palette of materials, including elastic-perfectly plastic materials and potentially brittle materials.

  18. Stable particle motion in a linear accelerator with solenoid focusing

    International Nuclear Information System (INIS)

    Wadlinger, E.A.

    1979-01-01

    The equation governing stable particle motion in a linear ion accelerator containing discrete rf and either discrete or continuous solenoid focusing was derived. It was found for discrete solenoid focusing that: cos μ = (1 + dΔ) cos theta/2 + (lΔ/theta - dtheta/2l - thetaΔd 2 /4l) sin theta/2, Δ = 1/f and l + 2d = βlambda, where μ, theta, f, l, and d are the phase advance per cell, precession angle in the solenoid, focal length of the rf lens, length of the solenoid in one cell, and the drift distance between the center of the rf gap and the effective edge of the solenoid. The relation for a continuous solenoid is found by setting d equal to zero. The boundaries of the stability region for theta vs Δ with fixed l and d are obtained when cos μ =+-1

  19. Two Bistable Switches Govern M Phase Entry.

    Science.gov (United States)

    Mochida, Satoru; Rata, Scott; Hino, Hirotsugu; Nagai, Takeharu; Novák, Béla

    2016-12-19

    The abrupt and irreversible transition from interphase to M phase is essential to separate DNA replication from chromosome segregation. This transition requires the switch-like phosphorylation of hundreds of proteins by the cyclin-dependent kinase 1 (Cdk1):cyclin B (CycB) complex. Previous studies have ascribed these switch-like phosphorylations to the auto-activation of Cdk1:CycB through the removal of inhibitory phosphorylations on Cdk1-Tyr15 [1, 2]. The positive feedback in Cdk1 activation creates a bistable switch that makes mitotic commitment irreversible [2-4]. Here, we surprisingly find that Cdk1 auto-activation is dispensable for irreversible, switch-like mitotic entry due to a second mechanism, whereby Cdk1:CycB inhibits its counteracting phosphatase (PP2A:B55). We show that the PP2A:B55-inhibiting Greatwall (Gwl)-endosulfine (ENSA) pathway is both necessary and sufficient for switch-like phosphorylations of mitotic substrates. Using purified components of the Gwl-ENSA pathway in a reconstituted system, we found a sharp Cdk1 threshold for phosphorylation of a luminescent mitotic substrate. The Cdk1 threshold to induce mitotic phosphorylation is distinctly higher than the Cdk1 threshold required to maintain these phosphorylations-evidence for bistability. A combination of mathematical modeling and biochemical reconstitution show that the bistable behavior of the Gwl-ENSA pathway emerges from its mutual antagonism with PP2A:B55. Our results demonstrate that two interlinked bistable mechanisms provide a robust solution for irreversible and switch-like mitotic entry. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Survey of the laser-solenoid fusion reactor

    International Nuclear Information System (INIS)

    Amherd, N.A.

    1975-09-01

    This report surveys the prospects for a laser-solenoid fusion reactor. A sample reactor and scaling laws are used to describe the concept's characteristics. Experimental results are reviewed, and the laser and magnet technologies that undergird the laser-solenoid concept are analyzed. Finally, a systems analysis of fusion power reactors is given, including a discussion of direct conversion and fusion-fission effects, to ascertain the system attributes of the laser-solenoid configuration

  1. Interlinked bistable mechanisms generate robust mitotic transitions.

    Science.gov (United States)

    Hutter, Lukas H; Rata, Scott; Hochegger, Helfrid; Novák, Béla

    2017-10-18

    The transitions between phases of the cell cycle have evolved to be robust and switch-like, which ensures temporal separation of DNA replication, sister chromatid separation, and cell division. Mathematical models describing the biochemical interaction networks of cell cycle regulators attribute these properties to underlying bistable switches, which inherently generate robust, switch-like, and irreversible transitions between states. We have recently presented new mathematical models for two control systems that regulate crucial transitions in the cell cycle: mitotic entry and exit, 1 and the mitotic checkpoint. 2 Each of the two control systems is characterized by two interlinked bistable switches. In the case of mitotic checkpoint control, these switches are mutually activating, whereas in the case of the mitotic entry/exit network, the switches are mutually inhibiting. In this Perspective we describe the qualitative features of these regulatory motifs and show that having two interlinked bistable mechanisms further enhances robustness and irreversibility. We speculate that these network motifs also underlie other cell cycle transitions and cellular transitions between distinct biochemical states.

  2. Dynamics of unidirectionally coupled bistable Henon maps

    International Nuclear Information System (INIS)

    Sausedo-Solorio, J.M.; Pisarchik, A.N.

    2011-01-01

    We study dynamics of two bistable Henon maps coupled in a master-slave configuration. In the case of coexistence of two periodic orbits, the slave map evolves into the master map state after transients, which duration determines synchronization time and obeys a -1/2 power law with respect to the coupling strength. This scaling law is almost independent of the map parameter. In the case of coexistence of chaotic and periodic attractors, very complex dynamics is observed, including the emergence of new attractors as the coupling strength is increased. The attractor of the master map always exists in the slave map independently of the coupling strength. For a high coupling strength, complete synchronization can be achieved only for the attractor similar to that of the master map. -- Highlights: → We study dynamics of two bistable Henon maps coupled in a master-slave configuration. → Synchronization time for periodic orbits obeys a -1/2 power law with respect to coupling. → For a high coupling strength, the slave map remains bistable. → Complete synchronization can be achieved only when both maps stay at the same attractor.

  3. Functional and genomic analyses of alpha-solenoid proteins.

    Science.gov (United States)

    Fournier, David; Palidwor, Gareth A; Shcherbinin, Sergey; Szengel, Angelika; Schaefer, Martin H; Perez-Iratxeta, Carol; Andrade-Navarro, Miguel A

    2013-01-01

    Alpha-solenoids are flexible protein structural domains formed by ensembles of alpha-helical repeats (Armadillo and HEAT repeats among others). While homology can be used to detect many of these repeats, some alpha-solenoids have very little sequence homology to proteins of known structure and we expect that many remain undetected. We previously developed a method for detection of alpha-helical repeats based on a neural network trained on a dataset of protein structures. Here we improved the detection algorithm and updated the training dataset using recently solved structures of alpha-solenoids. Unexpectedly, we identified occurrences of alpha-solenoids in solved protein structures that escaped attention, for example within the core of the catalytic subunit of PI3KC. Our results expand the current set of known alpha-solenoids. Application of our tool to the protein universe allowed us to detect their significant enrichment in proteins interacting with many proteins, confirming that alpha-solenoids are generally involved in protein-protein interactions. We then studied the taxonomic distribution of alpha-solenoids to discuss an evolutionary scenario for the emergence of this type of domain, speculating that alpha-solenoids have emerged in multiple taxa in independent events by convergent evolution. We observe a higher rate of alpha-solenoids in eukaryotic genomes and in some prokaryotic families, such as Cyanobacteria and Planctomycetes, which could be associated to increased cellular complexity. The method is available at http://cbdm.mdc-berlin.de/~ard2/.

  4. Approximate theory the electromagnetic energy of solenoid in special relativity

    International Nuclear Information System (INIS)

    Prastyaningrum, I; Kartikaningsih, S.

    2017-01-01

    Solenoid is a device that is often used in electronic devices. A solenoid is electrified will cause a magnetic field. In our analysis, we just focus on the electromagnetic energy for solenoid form. We purpose to analyze by the theoretical approach in special relativity. Our approach is begun on the Biot Savart law and Lorentz force. Special theory relativity can be derived from the Biot Savart law, and for the energy can be derived from Lorentz for, by first determining the momentum equation. We choose the solenoid form with the goal of the future can be used to improve the efficiency of the electrical motor. (paper)

  5. Calculus of the Cryebis 2 supraconductor solenoid

    International Nuclear Information System (INIS)

    Levy, G.

    1985-01-01

    This report describes the design of the superconducting solenoid CRYEBIS 2. With the prescribed parameters (5 Teslas central field, 120mm for inner diameter, 1600 mm for length), one determinates the dimensions of coil, its energy, the conductor, the working point of the magnet with its critical limits (intensity, field, temperature). The superconducting switch is calculated in the same manner. The study of a quench shows the good behaviour of the coil which is always safe even the detection system is in failure. In final, the mechanical stresses are verified lower than yield strength [fr

  6. Superconducting solenoid model magnet test results

    Energy Technology Data Exchange (ETDEWEB)

    Carcagno, R.; Dimarco, J.; Feher, S.; Ginsburg, C.M.; Hess, C.; Kashikhin, V.V.; Orris, D.F.; Pischalnikov, Y.; Sylvester, C.; Tartaglia, M.A.; Terechkine, I.; /Fermilab

    2006-08-01

    Superconducting solenoid magnets suitable for the room temperature front end of the Fermilab High Intensity Neutrino Source (formerly known as Proton Driver), an 8 GeV superconducting H- linac, have been designed and fabricated at Fermilab, and tested in the Fermilab Magnet Test Facility. We report here results of studies on the first model magnets in this program, including the mechanical properties during fabrication and testing in liquid helium at 4.2 K, quench performance, and magnetic field measurements. We also describe new test facility systems and instrumentation that have been developed to accomplish these tests.

  7. Superconducting solenoid model magnet test results

    International Nuclear Information System (INIS)

    Carcagno, R.; Dimarco, J.; Feher, S.; Ginsburg, C.M.; Hess, C.; Kashikhin, V.V.; Orris, D.F.; Pischalnikov, Y.; Sylvester, C.; Tartaglia, M.A.; Terechkine, I.; Tompkins, J.C.; Wokas, T.; Fermilab

    2006-01-01

    Superconducting solenoid magnets suitable for the room temperature front end of the Fermilab High Intensity Neutrino Source (formerly known as Proton Driver), an 8 GeV superconducting H- linac, have been designed and fabricated at Fermilab, and tested in the Fermilab Magnet Test Facility. We report here results of studies on the first model magnets in this program, including the mechanical properties during fabrication and testing in liquid helium at 4.2 K, quench performance, and magnetic field measurements. We also describe new test facility systems and instrumentation that have been developed to accomplish these tests

  8. ITER central solenoid manufacturing R and D

    International Nuclear Information System (INIS)

    Jay Jayakumar, R.; Tsuji, H.; Ohsaki, O.

    2001-01-01

    The International Thermonuclear Experimental Reactor (ITER) Engineering Design Activity (EDA) includes the development of high performance superconductors, high current joints between superconducting cables and insulating materials. Also in the EDA, the resulting products of this R and D are incorporated in a Central Solenoid Model Coil which utilizes full size conductors. The manufacturing of the model coil and components has led to the development of the design, materials, tooling and process which are fully applicable to the manufacture of the ITER relevant CS coil. The R and D is essentially complete and final stages of the CS Model Coil manufacturing are underway. (author)

  9. ITER central solenoid manufacturing R and D

    International Nuclear Information System (INIS)

    Jayakumar, R.J.; Tsuji, H.; Ohsaki, O.

    1999-01-01

    The International Thermonuclear Experimental Reactor (ITER) Engineering Design Activity (EDA) includes the development of high performance superconductors, high current joints between superconducting cables and insulating materials. Also in the EDA, the resulting products of this R and D are incorporated in a Central Solenoid Model Coil which utilizes full size conductors. The manufacturing of the model coil and components has led to the development of the design, materials, tooling and process which are fully applicable to the manufacture of the ITER relevant CS coil. The R and D is essentially complete and final stages of the CS Model Coil manufacturing are underway. (author)

  10. Conceptual design of a 20 Tesla pulsed solenoid for a laser solenoid fusion reactor

    International Nuclear Information System (INIS)

    Nolan, J.J.; Averill, R.J.

    1977-01-01

    Design considerations are described for a strip wound solenoid which is pulsed to 20 tesla while immersed in a 20 tesla bias field so as to achieve within the bore of the pulsed solenoid at net field sequence starting at 20 tesla and going first down to zero, then up to 40 tesla, and finally back to 20 tesla in a period of about 5 x 10 -3 seconds. The important parameters of the solenoid, e.g., aperture, build, turns, stored and dissipated energy, field intensity and powering circuit, are given. A numerical example for a specific design is presented. Mechanical stresses in the solenoid and the subsequent choice of materials for coil construction are discussed. Although several possible design difficulties are not discussed in this preliminary report of a conceptual magnet design, such as uniformity of field, long-term stability of insulation under neutron bombardment and choice of structural materials of appropriate tensile strength and elasticity to withstand magnetic forces developed, these questions are addressed in detail in the complete design report and in part in reference one. Furthermore, the authors feel that the problems encountered in this conceptual design are surmountable and are not a hindrance to the construction of such a magnet system

  11. First detector installed inside the ALICE solenoid...

    CERN Multimedia

    2006-01-01

    ALICE's emblematic red magnet welcomed its first detector on 23 September, when the array of seven Cherenkov detectors, named HMPID, was successfully installed. ALICE team members standing in front of the completed HMPID detector.The red magnet, viewed from its front opening. The HMPID unit, seen from the back (top right corner of photo) is placed on a frame and lifted onto a platform during the installation. After the installation of the ACORDE scintillator array and the muon trigger and tracking chambers, the ALICE collaboration fitted the first detector inside the solenoid. The HMPID, for High Momentum Particle Identification, was installed at the 2 o'clock position in the central and most external region of the space frame, just below the solenoid yoke. It will be used to extend the hadron identification capability of the ALICE experiment up to 5 GeV/c, thus complementing the reach of the other particle identification systems (ITS, TPC and TOF). The HMPID is a Ring Imaging Cherenkov (RICH) detector in a...

  12. Design of permanent magnetic solenoids for REGAE

    Energy Technology Data Exchange (ETDEWEB)

    Gehrke, Tim

    2013-10-15

    The Relativistic Electron Gun for Atomic Exploration (REGAE) is a small linear accelerator at DESY in Hamburg, which produces short, low emittance electron bunches. It is originally designed and built for ultrafast electron diffraction (UED) within the framework of the Center for Free-Electron Laser Science (CFEL). Additionally, two future experiments are planned at REGAE. First, an external injection experiment for Laser Wakefield Acceleration (LWA) will be performed in the framework of the LAOLA collaboration (LAboratory fOr Laser- and beam-driven plasma Acceleration). This experiment will provide a method for the reconstruction of the electric field distribution within a linear plasma wakefield. Second, a time resolving high energy Transmission Electron Microscope (TEM) will be implemented. Among others it is designed to allow for living cell imaging. Both experiments require strong focusing magnets inside the new target chamber at REGAE. Permanent magnetic solenoids (PMSs) can provide the needed focusing strength due to their enormous surface current density, while having compact dimensions at the same time. The present thesis deals with the design of such strong focusing PMSs. Since short and strong solenoids, as required for REGAE, exhibit a distinct non-linearity, the induced emittance growth is relatively large. This emittance growth is investigated and minimized for different set-ups with axially and radially magnetized annular magnets. Furthermore a magnetic shielding is developed. Together with a mechanical lifting system it assures that magnetic leakage fields do not disturb experiments, where the PMSs are removed from the beamline.

  13. Report of the large solenoid detector group

    International Nuclear Information System (INIS)

    Hanson, G.G.; Mori, S.; Pondrom, L.G.

    1987-09-01

    This report presents a conceptual design of a large solenoid for studying physics at the SSC. The parameters and nature of the detector have been chosen based on present estimates of what is required to allow the study of heavy quarks, supersymmetry, heavy Higgs particles, WW scattering at large invariant masses, new W and Z bosons, and very large momentum transfer parton-parton scattering. Simply stated, the goal is to obtain optimum detection and identification of electrons, muons, neutrinos, jets, W's and Z's over a large rapidity region. The primary region of interest extends over +-3 units of rapidity, although the calorimetry must extend to +-5.5 units if optimal missing energy resolution is to be obtained. A magnetic field was incorporated because of the importance of identifying the signs of the charges for both electrons and muons and because of the added possibility of identifying tau leptons and secondary vertices. In addition, the existence of a magnetic field may prove useful for studying new physics processes about which we currently have no knowledge. Since hermeticity of the calorimetry is extremely important, the entire central and endcap calorimeters were located inside the solenoid. This does not at the moment seem to produce significant problems (although many issues remain to be resolved) and in fact leads to a very effective muon detector in the central region

  14. The D0 solenoid NMR magnetometer

    International Nuclear Information System (INIS)

    Sten Uldall Hansen; Terry Kiper; Tom Regan; John Lofgren

    2002-01-01

    A field monitoring system for the 2 Tesla Solenoid of the D0 detector is described. It is comprised of a very small NMR probe cabled to a DSP based signal processing board. The design magnetic field range is from 1.0 to 2.2 Tesla, corresponding to an RF frequency range of 42.57 to 93.67 MHz. The desired an accuracy is one part in 10 5 . To minimize material in the interaction region of the D0 detector, the overall thickness of the NMR probe is 4 mm, including its mounting plate, and its width is 10 mm. To minimize cable mass, 4mm diameter IMR-100A cables are used for transmitting the RF signals from a nearby patch panel 25 meters to each of four probes mounted within the bore of the solenoid. RG213U cables 45 meters long are used to send the RF from the movable counting house to the patch panel. With this setup, the detector signal voltage at the moving counting room is in the range of 250-400 mV

  15. Design of permanent magnetic solenoids for REGAE

    International Nuclear Information System (INIS)

    Gehrke, Tim

    2013-10-01

    The Relativistic Electron Gun for Atomic Exploration (REGAE) is a small linear accelerator at DESY in Hamburg, which produces short, low emittance electron bunches. It is originally designed and built for ultrafast electron diffraction (UED) within the framework of the Center for Free-Electron Laser Science (CFEL). Additionally, two future experiments are planned at REGAE. First, an external injection experiment for Laser Wakefield Acceleration (LWA) will be performed in the framework of the LAOLA collaboration (LAboratory fOr Laser- and beam-driven plasma Acceleration). This experiment will provide a method for the reconstruction of the electric field distribution within a linear plasma wakefield. Second, a time resolving high energy Transmission Electron Microscope (TEM) will be implemented. Among others it is designed to allow for living cell imaging. Both experiments require strong focusing magnets inside the new target chamber at REGAE. Permanent magnetic solenoids (PMSs) can provide the needed focusing strength due to their enormous surface current density, while having compact dimensions at the same time. The present thesis deals with the design of such strong focusing PMSs. Since short and strong solenoids, as required for REGAE, exhibit a distinct non-linearity, the induced emittance growth is relatively large. This emittance growth is investigated and minimized for different set-ups with axially and radially magnetized annular magnets. Furthermore a magnetic shielding is developed. Together with a mechanical lifting system it assures that magnetic leakage fields do not disturb experiments, where the PMSs are removed from the beamline.

  16. Steady state statistical correlations predict bistability in reaction motifs.

    Science.gov (United States)

    Chakravarty, Suchana; Barik, Debashis

    2017-03-28

    Various cellular decision making processes are regulated by bistable switches that take graded input signals and convert them to binary all-or-none responses. Traditionally, a bistable switch generated by a positive feedback loop is characterized either by a hysteretic signal response curve with two distinct signaling thresholds or by characterizing the bimodality of the response distribution in the bistable region. To identify the intrinsic bistability of a feedback regulated network, here we propose that bistability can be determined by correlating higher order moments and cumulants (≥2) of the joint steady state distributions of two components connected in a positive feedback loop. We performed stochastic simulations of four feedback regulated models with intrinsic bistability and we show that for a bistable switch with variation of the signal dose, the steady state variance vs. covariance adopts a signatory cusp-shaped curve. Further, we find that the (n + 1)th order cross-cumulant vs. nth order cross-cumulant adopts a closed loop structure for at least n = 3. We also propose that our method is capable of identifying systems without intrinsic bistability even though the system may show bimodality in the marginal response distribution. The proposed method can be used to analyze single cell protein data measured at steady state from experiments such as flow cytometry.

  17. Bubbling and bistability in two parameter discrete systems

    OpenAIRE

    Ambika, G.; Sujatha, N. V.

    2000-01-01

    We present a graphical analysis of the mechanisms underlying the occurrences of bubbling sequences and bistability regions in the bifurcation scenario of a special class of one dimensional two parameter maps. The main result of the analysis is that whether it is bubbling or bistability is decided by the sign of the third derivative at the inflection point of the map function.

  18. Bistable polarization switching in a continuous wave ruby laser

    Science.gov (United States)

    Lawandy, N. M.; Afzal, R. Sohrab

    1988-01-01

    Bistability in the output power, polarization state, and mode volume of an argon-ion laser pumped single mode ruby laser at 6943 A has been observed. The laser operates in a radially confined mode which exhibits hysteresis and bistability only when the pump polarization is parallel to the c-axis.

  19. Bistable soliton states and switching in doubly inhomogeneously ...

    Indian Academy of Sciences (India)

    Dec. 2001 physics pp. 969–979. Bistable soliton states and switching in doubly inhomogeneously doped fiber couplers. AJIT KUMAR. Department of Physics, Indian Institute of Technology, Hauz Khas, New Delhi 110 016, India. Abstract. Switching between the bistable soliton states in a doubly and inhomogeneously doped.

  20. Multistability in Bistable Ferroelectric Materials toward Adaptive Applications

    NARCIS (Netherlands)

    Ghosh, Anirban; Koster, Gertjan; Rijnders, Augustinus J.H.M.

    2016-01-01

    Traditionally thermodynamically bistable ferroic materials are used for nonvolatile operations based on logic gates (e.g., in the form of field effect transistors). But, this inherent bistability in these class of materials limits their applicability for adaptive operations. Emulating biological

  1. Optical bistability using quantum interference in V-type atoms

    International Nuclear Information System (INIS)

    Anton, M A; Calderon, Oscar G

    2002-01-01

    The behaviour of a V-type three-level atomic system in a ring cavity driven by a coherent field is studied. We consider a V configuration under conditions such that interference between decay channels is important. We find that when quantum interference is taken into account, optical bistability can be realized with a considerable decrease in the threshold intensity and the cooperative parameter. On the other hand, we also include the finite bandwidth of the driving field and study its role in the optical bistable response. It is found that at certain linewidths of the driving field optical bistability is obtained even if the system satisfies the trapping condition and the threshold intensity can be controlled. Furthermore, a change from the optical bistability due to quantum interference to the usual bistable behaviour based on saturation occurs as the driving field linewidth increases

  2. Plasma confinement apparatus using solenoidal and mirror coils

    International Nuclear Information System (INIS)

    Fowler, T.K.; Condit, W.C.

    1979-01-01

    A plasma confinement apparatus is described, wherein multiple magnetic mirror cells are linked by magnetic field lines inside of a solenoid with the mirroring regions for adjacent magnetic mirror cells each formed by a separate mirror coil inside of the solenoid. The magnetic mirror cells may be field reversed

  3. Plasma confinement apparatus using solenoidal and mirror coils

    Science.gov (United States)

    Fowler, T. Kenneth; Condit, William C.

    1979-01-01

    A plasma confinement apparatus, wherein multiple magnetic mirror cells are linked by magnetic field lines inside of a solenoid with the mirroring regions for adjacent magnetic mirror cells each formed by a separate mirror coil inside of the solenoid. The magnetic mirror cells may be field reversed.

  4. Novel five-state latch using double-peak negative differential resistance and standard ternary inverter

    Science.gov (United States)

    Shin, Sunhae; Rok Kim, Kyung

    2016-04-01

    We propose complement double-peak negative differential resistance (NDR) devices with ultrahigh peak-to-valley current ratio (PVCR) over 106 by combining tunnel diode with conventional CMOS and its compact five-state latch circuit by introducing standard ternary inverter (STI). At the “high”-state of STI, n-type NDR device (tunnel diode with nMOS) has 1st NDR characteristics with 1st peak and valley by band-to-band tunneling (BTBT) and trap-assisted tunneling (TAT), whereas p-type NDR device (tunnel diode with pMOS) has second NDR characteristics from the suppression of diode current by off-state MOSFET. The “intermediate”-state of STI permits double-peak NDR device to operate five-state latch with only four transistors, which has 33% area reduction compared with that of binary inverter and 57% bit-density reduction compared with binary latch.

  5. Force analysis of the advanced neutron source control rod drive latch mechanism

    International Nuclear Information System (INIS)

    Damiano, B.

    1989-01-01

    The Advanced Neutron Source reactor (ANS), a proposed Department of Energy research reactor currently undergoing conceptual design at the Oak Ridge National Laboratory (ORNL), will generate a thermal neutron flux approximating 10 30 M -2 emdash S -1 . The compact core necessary to produce this flux provides little space for the shim safety control rods, which are located in the central annulus of the core. Without proper control rod drive design, the control rod drive magnets (which hold the control rod latch in a ready-to-scram position) may be unable to support the required load due to their restricted size. This paper describes the force analysis performed on the control rod latch mechanism to determine the fraction of control rod weight transferred to the drive magnet. This information will be useful during latch, control rod drive and magnet design. 5 refs., 12 figs

  6. SEM technique for experimentally locating latch-up paths in integrated circuits

    International Nuclear Information System (INIS)

    Dressendorfer, P.V.; Armendariz, M.G.

    1980-01-01

    A technique is presented for using the scanning electron microscope (SEM) in the electron-beam-induced current (EBIC) mode to delineate latch-up paths in CMOS ICs. In the EBIC mode, the current produced by the collection and separation of the electron-beam-generated electron-hole pairs in the space charge regions of the device is measured and used to form an image. Since the collection of these carriers is dependent on space charge region width (and thus junction potential), anything that alters the depletion layer width will affect the collection efficiency. In a latch condition the junctions involved in the latch will be biased differently from those which are not, and thus the EBIC signal from those regions should be measurably different

  7. The Design Parameters for the MICE Tracker Solenoid

    International Nuclear Information System (INIS)

    Green, Michael A.; Chen, C.Y.; Juang, Tiki; Lau, Wing W.; Taylor, Clyde; Virostek, Steve P.; Wahrer, Robert; Wang, S.T.; Witte, Holger; Yang, Stephanie Q.

    2006-01-01

    The first superconducting magnets to be installed in the muon ionization cooling experiment (MICE) will be the tracker solenoids. The tracker solenoid module is a five coil superconducting solenoid with a 400 mm diameter warm bore that is used to provide a 4 T magnetic field for the experiment tracker module. Three of the coils are used to produce a uniform field (up to 4 T with better than 1 percent uniformity) in a region that is 300 mm in diameter and 1000 mm long. The other two coils are used to match the muon beam into the MICE cooling channel. Two 2.94-meter long superconducting tracker solenoid modules have been ordered for MICE. The tracker solenoid will be cooled using two-coolers that produce 1.5 W each at 4.2 K. The magnet system is described. The decisions that drive the magnet design will be discussed in this report

  8. Pressure control valve using proportional electro-magnetic solenoid actuator

    International Nuclear Information System (INIS)

    Yun, So Nam; Ham, Young Bog; Park, Pyoung Won

    2006-01-01

    This paper presents an experimental characteristics of electro-hydraulic proportional pressure control valve. In this study, poppet and valve body which are assembled into the proportional solenoid were designed and manufactured. The constant force characteristics of proportional solenoid actuator in the control region should be independent of the plunger position in order to be used to control the valve position in the fluid flow control system. The stroke-force characteristics of the proportional solenoid actuator is determined by the shape (or parameters) of the control cone. In this paper, steady state and transient characteristics of the solenoid actuator for electro-hydraulic proportional valve are analyzed using finite element method and it is confirmed that the proportional solenoid actuator has a constant attraction force in the control region independently on the stroke position. The effects of the parameters such as control cone length, thickness and taper length are also discussed

  9. A hierarchical stochastic model for bistable perception.

    Directory of Open Access Journals (Sweden)

    Stefan Albert

    2017-11-01

    Full Text Available Viewing of ambiguous stimuli can lead to bistable perception alternating between the possible percepts. During continuous presentation of ambiguous stimuli, percept changes occur as single events, whereas during intermittent presentation of ambiguous stimuli, percept changes occur at more or less regular intervals either as single events or bursts. Response patterns can be highly variable and have been reported to show systematic differences between patients with schizophrenia and healthy controls. Existing models of bistable perception often use detailed assumptions and large parameter sets which make parameter estimation challenging. Here we propose a parsimonious stochastic model that provides a link between empirical data analysis of the observed response patterns and detailed models of underlying neuronal processes. Firstly, we use a Hidden Markov Model (HMM for the times between percept changes, which assumes one single state in continuous presentation and a stable and an unstable state in intermittent presentation. The HMM captures the observed differences between patients with schizophrenia and healthy controls, but remains descriptive. Therefore, we secondly propose a hierarchical Brownian model (HBM, which produces similar response patterns but also provides a relation to potential underlying mechanisms. The main idea is that neuronal activity is described as an activity difference between two competing neuronal populations reflected in Brownian motions with drift. This differential activity generates switching between the two conflicting percepts and between stable and unstable states with similar mechanisms on different neuronal levels. With only a small number of parameters, the HBM can be fitted closely to a high variety of response patterns and captures group differences between healthy controls and patients with schizophrenia. At the same time, it provides a link to mechanistic models of bistable perception, linking the group

  10. A hierarchical stochastic model for bistable perception.

    Science.gov (United States)

    Albert, Stefan; Schmack, Katharina; Sterzer, Philipp; Schneider, Gaby

    2017-11-01

    Viewing of ambiguous stimuli can lead to bistable perception alternating between the possible percepts. During continuous presentation of ambiguous stimuli, percept changes occur as single events, whereas during intermittent presentation of ambiguous stimuli, percept changes occur at more or less regular intervals either as single events or bursts. Response patterns can be highly variable and have been reported to show systematic differences between patients with schizophrenia and healthy controls. Existing models of bistable perception often use detailed assumptions and large parameter sets which make parameter estimation challenging. Here we propose a parsimonious stochastic model that provides a link between empirical data analysis of the observed response patterns and detailed models of underlying neuronal processes. Firstly, we use a Hidden Markov Model (HMM) for the times between percept changes, which assumes one single state in continuous presentation and a stable and an unstable state in intermittent presentation. The HMM captures the observed differences between patients with schizophrenia and healthy controls, but remains descriptive. Therefore, we secondly propose a hierarchical Brownian model (HBM), which produces similar response patterns but also provides a relation to potential underlying mechanisms. The main idea is that neuronal activity is described as an activity difference between two competing neuronal populations reflected in Brownian motions with drift. This differential activity generates switching between the two conflicting percepts and between stable and unstable states with similar mechanisms on different neuronal levels. With only a small number of parameters, the HBM can be fitted closely to a high variety of response patterns and captures group differences between healthy controls and patients with schizophrenia. At the same time, it provides a link to mechanistic models of bistable perception, linking the group differences to

  11. Technological parameter and experimental set-up influences on latch-up triggering level in bulk CMOS device

    International Nuclear Information System (INIS)

    Dubuc, J.P.; Azais, B.; Murcia, M. de

    1994-01-01

    This paper deals with experimental and simulation results on latch-up triggered by an electrical or X-rays pulse in CMOS/bulk devices. Test condition influences as well as the great importance of process parameters on latch-up immunity are emphasized. (author). 10 refs., 19 figs., 1 tab

  12. A Modular, Reusable Latch and Decking System for Securing Payloads During Launch and Planetary Surface Transport

    Science.gov (United States)

    Doggett, William R.; Dorsey, John T.; Jones, Thomas C.; King, Bruce D.; Mikulas, Martin M.

    2011-01-01

    Efficient handling of payloads destined for a planetary surface, such as the moon or mars, requires robust systems to secure the payloads during transport on the ground, in space and on the planetary surface. In addition, mechanisms to release the payloads need to be reliable to ensure successful transfer from one vehicle to another. An efficient payload handling strategy must also consider the devices available to support payload handling. Cranes used for overhead lifting are common to all phases of payload handling on Earth. Similarly, both recent and past studies have demonstrated that devices with comparable functionality will be needed to support lunar outpost operations. A first generation test-bed of a new high performance device that provides the capabilities of both a crane and a robotic manipulator, the Lunar Surface Manipulation System (LSMS), has been designed, built and field tested and is available for use in evaluating a system to secure payloads to transportation vehicles. A payload handling approach must address all phases of payload management including: ground transportation, launch, planetary transfer and installation in the final system. In addition, storage may be required during any phase of operations. Each of these phases requires the payload to be lifted and secured to a vehicle, transported, released and lifted in preparation for the next transportation or storage phase. A critical component of a successful payload handling approach is a latch and associated carrier system. The latch and carrier system should minimize requirements on the: payload, carrier support structure and payload handling devices as well as be able to accommodate a wide range of payload sizes. In addition, the latch should; be small and lightweight, support a method to apply preload, be reusable, integrate into a minimal set of hard-points and have manual interfaces to actuate the latch should a problem occur. A latching system which meets these requirements has been

  13. Superconducting Solenoid for Superfast THz Spectroscopy

    Science.gov (United States)

    Bragin, A. V.; Khrushchev, S. V.; Kubarev, V. V.; Mezencev, N. A.; Tsukanov, V. M.; Sozinov, G. I.; Shkaruba, V. A.

    This project is related to new spectroscopy method in little-developed THz range. The method is founded on using of a free electron laser (NovoFEL) with high spectral power radiation which can be smoothly tuned in desirable range of spectrum. The objects of research of this method are fast processes in physics, chemical and biological reactions. Uniform magnetic field of 6 T value in the research area can considerably increase possibilities of this method. The magnetic field will modulate radiation of free molecules induction on characteristic frequencies of the Zeeman splitting that gives more possibilities of identification of molecules having even weak magnetic momentum. Moreover, the use of magnetic field allows essentially increase sensitivity of this method due to almost complete separation of weak measuring signals from powerful radiation of the laser. A superconducting solenoid was developed for this method. Its design and peculiarities are described in this paper.

  14. Concept design of the CFETR central solenoid

    International Nuclear Information System (INIS)

    Zheng, Jinxing; Song, Yuntao; Liu, Xufeng; Li, Jiangang; Wan, Yuanxi; Wan, Baonian; Ye, Minyou; Wu, Huan

    2015-01-01

    Highlights: • Main concept design work including coil's geometry, superconductor and support structure has been carried out. • The maximum magnetic field of CS coil is 11.9 T which is calculated by the coils’ operation current based on plasma equilibrium configuration. • The stray field in plasma area is less than 20 Gs under the CS coils’ operation currents designed for the plasma-heating phase. - Abstract: China Fusion Engineering Test Reactor (CFETR) superconducting tokamak is a national scientific research project of China with major and minor radius is 5.7 m and 1.6 m respectively. The magnetic field at the center of plasma with radius as R = 5.7 m is set to be 5.0 T. The major objective of the project is to build a fusion engineering tokamak reactor with fusion power in the range of 50–200 MW and should be self-sufficient by blanket. Six central solenoid coils of CFETR with same structure are made of Nb 3 Sn superconductor. Besides, the stray field in plasma area should be less than 20 Gs with the operation current of CS coils for plasma heating phase. The maximum magnetic field of CS coil is 11.9 T. It is calculated by the coils’ operation current based on plasma equilibrium configuration. The central solenoid needs to have enough stability margin under the condition of high magnetic field and strain. This paper discusses the design parameters, electromagnetic distribution, structure and stability analysis of the CS superconducting magnet for CFETR

  15. On the bistable zone of milling processes.

    Science.gov (United States)

    Dombovari, Zoltan; Stepan, Gabor

    2015-09-28

    A modal-based model of milling machine tools subjected to time-periodic nonlinear cutting forces is introduced. The model describes the phenomenon of bistability for certain cutting parameters. In engineering, these parameter domains are referred to as unsafe zones, where steady-state milling may switch to chatter for certain perturbations. In mathematical terms, these are the parameter domains where the periodic solution of the corresponding nonlinear, time-periodic delay differential equation is linearly stable, but its domain of attraction is limited due to the existence of an unstable quasi-periodic solution emerging from a secondary Hopf bifurcation. A semi-numerical method is presented to identify the borders of these bistable zones by tracking the motion of the milling tool edges as they might leave the surface of the workpiece during the cutting operation. This requires the tracking of unstable quasi-periodic solutions and the checking of their grazing to a time-periodic switching surface in the infinite-dimensional phase space. As the parameters of the linear structural behaviour of the tool/machine tool system can be obtained by means of standard modal testing, the developed numerical algorithm provides efficient support for the design of milling processes with quick estimates of those parameter domains where chatter can still appear in spite of setting the parameters into linearly stable domains. © 2015 The Authors.

  16. Single coil bistable, bidirectional micromechanical actuator

    Science.gov (United States)

    Tabat, Ned; Guckel, Henry

    1998-09-15

    Micromechanical actuators capable of bidirectional and bistable operation can be formed on substrates using lithographic processing techniques. Bistable operation of the microactuator is obtained using a single coil and a magnetic core with a gap. A plunger having two magnetic heads is supported for back and forth linear movement with respect to the gap in the magnetic core, and is spring biased to a neutral position in which the two heads are on each side of the gap in the core. The single electrical coil is coupled to the core and is provided with electrical current to attract one of the heads toward the core by reluctance action to drive the plunger to a limit of travel in one direction. The current is then cut off and the plunger returns by spring action toward the gap, whereafter the current is reapplied to the coil to attract the other head of the plunger by reluctance action to drive the plunger to its other limit of travel. This process can be repeated at a time when switching of the actuator is required.

  17. Deployable structures using bistable reeled composites

    Science.gov (United States)

    Daton-Lovett, Andrew J.; Compton-Bishop, Quentin M.; Curry, Richard G.

    2000-06-01

    This paper describes an innovative, patented use of composite materials developed by RolaTube Technology Ltd. to make smart deployable structures. Bi-stable reeled composites (BRCs) can alternate between two stable forms; that of a strong, rigid structure and that of a compact coil of flat-wound material. Bi-stability arises as a result of the manipulation of Poisson's ratio and isotropy in the various layers of the material. BRCs are made of fiber- reinforced composite materials, most often with a thermoplastic matrix. A range of fibers and polymer matrices can be used according to the requirements of the operating environment. Samples of a BRC structure were constructed using layers of unidirectional, fiber-reinforced thermoplastic sheet with the layers at different angles. The whole assembly was then consolidated under conditions of elevated temperature and pressure. The properties of the BRC are described and the result of a series of experiments performed on the sample to determine the tensile strength of the BRC structure are reported. A full analysis using finite element methods is being undertaken in collaboration with the University of Cambridge, England. The first commercial use has been to fabricate boom and drive mechanisms for the remote inspection of industrial plant.

  18. Ca++ dependent bistability induced by serotonin in spinal motoneurons

    DEFF Research Database (Denmark)

    Hounsgaard, J.; Kiehn, O.

    1985-01-01

    The plateau potential, responsible for the bistable state of spinal motoneurons, recently described in the decerebrate cat, was suggested to depend on serotonin (Hounsgaard et al. 1984). In an in vitro preparation of the spinal cord of the turtle we now show that serotonin, applied directly...... to the bath, transforms the intrinsic response properties of motoneurons, uncovering a plateau potential and voltage sensitive bistability. The changes induced by serotonin were blocked by Mn++, while the plateau potential and the bistability remained after application of tetrodotoxin. We conclude...... that serotonin controls the expression of a Ca++ dependent plateau potential in motoneurons....

  19. Validation of Quench Simulation and Simulation of the TWIN Solenoid

    CERN Document Server

    Pots, Rosalinde Hendrika

    2015-01-01

    For the Future Circular Collider at CERN a multi-purpose detector is proposed. The 6T TWIN Solenoid, a very large magnet system with a stored energy of 53 GJ, is being designed. It is important to protect the magnet against quenches in the system. Therefore several existing quench protection systems are evaluated and simulations have be performed on quenches in the TWIN Solenoid. The simulations on quenches in the TWIN Solenoid have been performed with promising results; the hotspot temperatures do not exceed 120 K and layer to layer voltages stay below 500 V. Adding quench heaters to the system might improve the quench protection system further.

  20. Quench protection and safety of the ATLAS central solenoid

    CERN Document Server

    Makida, Y; Haruyama, T; ten Kate, H H J; Kawai, M; Kobayashi, T; Kondo, T; Kondo, Y; Mizumaki, S; Olesen, G; Sbrissa, E; Yamamoto, A; Yamaoka, H

    2002-01-01

    Fabrication of the ATLAS central solenoid was completed and the performance test has been carried out. The solenoid was successfully charged up to 8.4 kA, which is 10% higher than the normal operational current of 7.6 kA. Two methods for quench protection, pure aluminum strips accelerating quench propagation and quench protection heaters distributing normal zones, are applied in order to safely dissipate the stored energy. In this paper, quench characteristics and protection methods of the ATLAS central solenoid are described. (14 refs).

  1. A superconducting focusing solenoid for the neutrino factory linear accelerator

    International Nuclear Information System (INIS)

    Green, Michael A.; Lebedev, V.; Strauss, B.P.

    2001-01-01

    The proposed linear Accelerator that accelerates muons from 190 MeV to 2.45 GeV will use superconducting solenoids for focusing the muon beam. The accelerator will use superconducting RF cavities. These cavities are very sensitive to stay magnetic field from the focusing magnets. Superconducting solenoids can produce large stray fields. This report describes the 201.25 MHz acceleration system for the neutrino factory. This report also describes a focusing solenoid that delivers almost no stray field to a neighboring superconducting RF cavity

  2. Structure-function analysis of the OB and latch domains of chlorella virus DNA ligase.

    Science.gov (United States)

    Samai, Poulami; Shuman, Stewart

    2011-06-24

    Chlorella virus DNA ligase (ChVLig) is a minimized eukaryal ATP-dependent DNA sealing enzyme with an intrinsic nick-sensing function. ChVLig consists of three structural domains, nucleotidyltransferase (NTase), OB-fold, and latch, that envelop the nicked DNA as a C-shaped protein clamp. The OB domain engages the DNA minor groove on the face of the duplex behind the nick, and it makes contacts to amino acids in the NTase domain surrounding the ligase active site. The latch module occupies the DNA major groove flanking the nick. Residues at the tip of the latch contact the NTase domain to close the ligase clamp. Here we performed a structure-guided mutational analysis of the OB and latch domains. Alanine scanning defined seven individual amino acids as essential in vivo (Lys-274, Arg-285, Phe-286, and Val-288 in the OB domain; Asn-214, Phe-215, and Tyr-217 in the latch), after which structure-activity relations were clarified by conservative substitutions. Biochemical tests of the composite nick sealing reaction and of each of the three chemical steps of the ligation pathway highlighted the importance of Arg-285 and Phe-286 in the catalysis of the DNA adenylylation and phosphodiester synthesis reactions. Phe-286 interacts with the nick 5'-phosphate nucleotide and the 3'-OH base pair and distorts the DNA helical conformation at the nick. Arg-285 is a key component of the OB-NTase interface, where it forms a salt bridge to the essential Asp-29 side chain, which is imputed to coordinate divalent metal catalysts during the nick sealing steps.

  3. Structure-Function Analysis of the OB and Latch Domains of Chlorella Virus DNA Ligase*

    Science.gov (United States)

    Samai, Poulami; Shuman, Stewart

    2011-01-01

    Chlorella virus DNA ligase (ChVLig) is a minimized eukaryal ATP-dependent DNA sealing enzyme with an intrinsic nick-sensing function. ChVLig consists of three structural domains, nucleotidyltransferase (NTase), OB-fold, and latch, that envelop the nicked DNA as a C-shaped protein clamp. The OB domain engages the DNA minor groove on the face of the duplex behind the nick, and it makes contacts to amino acids in the NTase domain surrounding the ligase active site. The latch module occupies the DNA major groove flanking the nick. Residues at the tip of the latch contact the NTase domain to close the ligase clamp. Here we performed a structure-guided mutational analysis of the OB and latch domains. Alanine scanning defined seven individual amino acids as essential in vivo (Lys-274, Arg-285, Phe-286, and Val-288 in the OB domain; Asn-214, Phe-215, and Tyr-217 in the latch), after which structure-activity relations were clarified by conservative substitutions. Biochemical tests of the composite nick sealing reaction and of each of the three chemical steps of the ligation pathway highlighted the importance of Arg-285 and Phe-286 in the catalysis of the DNA adenylylation and phosphodiester synthesis reactions. Phe-286 interacts with the nick 5′-phosphate nucleotide and the 3′-OH base pair and distorts the DNA helical conformation at the nick. Arg-285 is a key component of the OB-NTase interface, where it forms a salt bridge to the essential Asp-29 side chain, which is imputed to coordinate divalent metal catalysts during the nick sealing steps. PMID:21527793

  4. High intensity neutrino source superconducting solenoid cyrostat design

    Energy Technology Data Exchange (ETDEWEB)

    Page, T.M.; Nicol, T.H.; Feher, S.; Terechkine, I.; Tompkins, J.; /Fermilab

    2006-06-01

    Fermi National Accelerator Laboratory (FNAL) is involved in the development of a 100 MeV superconducting linac. This linac is part of the High Intensity Neutrino Source (HINS) R&D Program. The initial beam acceleration in the front end section of the linac is achieved using room temperature spoke cavities, each of which is combined with a superconducting focusing solenoid. These solenoid magnets are cooled with liquid helium at 4.5K, operate at 250 A and have a maximum magnetic field strength of 7.5 T. The solenoid cryostat will house the helium vessel, suspension system, thermal shield, multilayer insulation, power leads, instrumentation, a vacuum vessel and cryogenic distribution lines. This paper discusses the requirements and detailed design of these superconducting solenoid cryostats.

  5. Solenoid hammer valve developed for quick-opening requirements

    Science.gov (United States)

    Wrench, E. H.

    1967-01-01

    Quick-opening lightweight solenoid hammer valve requires a low amount of electrical energy to open, and closes by the restoring action of the mechanical springs. This design should be applicable to many quick-opening requirements in fluid systems.

  6. Low-energy nuclear reactions with double-solenoid- based ...

    Indian Academy of Sciences (India)

    solenoids to produce low-energy radioactive nuclear beams. In these systems the ... For many years, the disadvantage in these investigations ... fusion or breakup reaction, preferred with large forward-peaked cross-sections. To transfer the ...

  7. Bistable responses in bacterial genetic networks: Designs and dynamical consequences

    Science.gov (United States)

    Tiwari, Abhinav; Ray, J. Christian J.; Narula, Jatin; Igoshin, Oleg A.

    2011-01-01

    A key property of living cells is their ability to react to stimuli with specific biochemical responses. These responses can be understood through the dynamics of underlying biochemical and genetic networks. Evolutionary design principles have been well studied in networks that display graded responses, with a continuous relationship between input signal and system output. Alternatively, biochemical networks can exhibit bistable responses so that over a range of signals the network possesses two stable steady states. In this review, we discuss several conceptual examples illustrating network designs that can result in a bistable response of the biochemical network. Next, we examine manifestations of these designs in bacterial master-regulatory genetic circuits. In particular, we discuss mechanisms and dynamic consequences of bistability in three circuits: two-component systems, sigma-factor networks, and a multistep phosphorelay. Analyzing these examples allows us to expand our knowledge of evolutionary design principles for networks with bistable responses. PMID:21385588

  8. Bistable luminescence of trivalent rare-earth ions in crystals

    International Nuclear Information System (INIS)

    Sole, Jose Garcia; Ramirez O, Maria de la; Rodenas, Airan; Jaque, Daniel; Bausa, Luisa; Bettinelli, Marco; Speghini, Adolfo; Cavalli, Enrico; Ivleva, Lioudmila

    2006-01-01

    In this work, we have examined three new bistable systems based on the luminescence of three different crystals activated with trivalent rare earth ions. We have focussed our attention on Yb 3+ ions activators, for which the most relevant results are obtained. The first crystal, Sr 0.6 Ba 0.4 Nb 2 O 6 , is a ferroelectric material with a relatively low phase transition temperature (∼370 K), which provides bistability in the luminescence of Yb 3+ ions due to the thermal hysteresis associated with phase transition. The second crystal, LiNbO 3 , provides an intrinsic bistability in the luminescence of Yb 3+ ions, which is driven by changes in the excitation intensity. In the third crystal, NdPO 4 , a new mechanism of excitation intensity driven bistability is obtained when activated with Yb 3+ ions, due to a interplay between the Nd 3+ ↔Yb 3+ energy transfer and back transfer processes

  9. Bifurcation of transition paths induced by coupled bistable systems.

    Science.gov (United States)

    Tian, Chengzhe; Mitarai, Namiko

    2016-06-07

    We discuss the transition paths in a coupled bistable system consisting of interacting multiple identical bistable motifs. We propose a simple model of coupled bistable gene circuits as an example and show that its transition paths are bifurcating. We then derive a criterion to predict the bifurcation of transition paths in a generalized coupled bistable system. We confirm the validity of the theory for the example system by numerical simulation. We also demonstrate in the example system that, if the steady states of individual gene circuits are not changed by the coupling, the bifurcation pattern is not dependent on the number of gene circuits. We further show that the transition rate exponentially decreases with the number of gene circuits when the transition path does not bifurcate, while a bifurcation facilitates the transition by lowering the quasi-potential energy barrier.

  10. Interaction of multiarmed spirals in bistable media.

    Science.gov (United States)

    He, Ya-feng; Ai, Bao-quan; Liu, Fu-cheng

    2013-05-01

    We study the interaction of both dense and sparse multiarmed spirals in bistable media modeled by equations of the FitzHugh-Nagumo type. A dense one-armed spiral is characterized by its fixed tip. For dense multiarmed spirals, when the initial distance between tips is less than a critical value, the arms collide, connect, and disconnect continuously as the spirals rotate. The continuous reconstruction between the front and the back drives the tips to corotate along a rough circle and to meander zigzaggedly. The rotation frequency of tip, the frequency of zigzagged displacement, the frequency of spiral, the oscillation frequency of media, and the number of arms satisfy certain relations as long as the control parameters of the model are fixed. When the initial distance between tips is larger than the critical value, the behaviors of individual arms within either dense or sparse multiarmed spirals are identical to that of corresponding one-armed spirals.

  11. Lattice stretching bistability and dynamic heterogeneity

    DEFF Research Database (Denmark)

    Christiansen, Peter Leth; Savin, A. V.; Zolotaryuk, A. V.

    2012-01-01

    A simple one-dimensional lattice model is suggested to describe the experimentally observed plateau in force-stretching diagrams for some macromolecules. This chain model involves the nearest-neighbor interaction of a Morse-like potential (required to have a saturation branch) and a harmonic second......-neighbor coupling. Under an external stretching applied to the chain ends, the intersite Morse-like potential results in the appearance of a double-well potential within each chain monomer, whereas the interaction between the second neighbors provides a homogeneous bistable (degenerate) ground state, at least...... stretched bonds with a double-well potential. This case allows us to explain the existence of a plateau in the force-extension diagram for DNA and α-helix protein. Finally, the soliton dynamics are studied in detail....

  12. A bistable electromagnetically actuated rotary gate microvalve

    International Nuclear Information System (INIS)

    Luharuka, Rajesh; Hesketh, Peter J

    2008-01-01

    Two types of rotary gate microvalves are developed for flow modulation in microfluidic systems. These microvalves have been tested for an open flow rate of up to 100 sccm and operate under a differential pressure of 6 psig with flow modulation of up to 100. The microvalve consists of a suspended gate that rotates in the plane of the chip to regulate flow through the orifice. The gate is suspended by a novel fully compliant in-plane rotary bistable micromechanism (IPRBM) that advantageously constrains the gate in all degrees of freedom except for in-plane rotational motion. Multiple inlet/outlet orifices provide flexibility of operating the microvalve in three different flow configurations. The rotary gate microvalve is switched with an external electromagnetic actuator. The suspended gate is made of a soft magnetic material and its electromagnetic actuation is based on the operating principle of a variable-reluctance stepper motor

  13. Cops or Robbers — a Bistable Society

    Science.gov (United States)

    Kułakowski, K.

    The norm game described by Axelrod in 1985 was recently treated with the master equation formalism. Here we discuss the equations, where (i) those who break the norm cannot punish and those who punish cannot break the norm, (ii) the tendency to punish is suppressed if the majority breaks the norm. The second mechanism is new. For some values of the parameters the solution shows the saddle-point bifurcation. Then, two stable solutions are possible, where the majority breaks the norm or the majority punishes. This means, that the norm breaking can be discontinuous, when measured in the social scale. The bistable character is reproduced also with new computer simulations on the Erdös-Rényi directed network.

  14. The solenoidal detector collaboration silicon detector system

    International Nuclear Information System (INIS)

    Ziock, H.J.; Gamble, M.T.; Miller, W.O.; Palounek, A.P.T.; Thompson, T.C.

    1992-01-01

    Silicon tracking systems (STS) will be fundamental components of the tracking systems for both planned major SSC experiments. The STS is physically a small part of the central tracking system and the calorimeter of the detector being proposed by the Solenoidal Detector Collaboration (SDC). Despite its seemingly small size, it occupies a volume of more than 5 meters in length and 1 meter in diameter and is an order of magnitude larger than any silicon detector system previously built. The STS will consist of silicon microstrip detectors and possibly silicon pixel detectors. The other two components are an outer barrel tracker, which will consist of straw tubes or scintillating fibers; and an outer intermediate angle tracker, which will consist of gas microstrips. The components are designed to work as an integrated system. Each componenet has specific strengths, but is individually incapable of providing the overall performance required by the physics goals of the SSC. The large particle fluxes, the short times between beam crossing, the high channel count, and the required very high position measurement accuracy pose challenging problems that must be solved. Furthermore, to avoid degrading the measurements, the solutions must be achieved using only a minimal amount of material. An additional constraint is that only low-Z materials are allowed. If that were not difficlut enough, the solutions must also be affordable

  15. The Compact Muon Solenoid Detector Control System

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    The Compact Muon Solenoid (CMS) is a CERN multi-purpose experiment that exploits the physics of the Large Hadron Collider (LHC). The Detector Control System (DCS) ensures a safe, correct and efficient experiment operation, contributing to the recording of high quality physics data. The DCS is programmed to automatically react to the LHC changes. CMS sub-detector’s bias voltages are set depending on the machine mode and particle beam conditions. A protection mechanism ensures that the sub-detectors are locked in a safe mode whenever a potentially dangerous situation exists. The system is supervised from the experiment control room by a single operator. A small set of screens summarizes the status of the detector from the approximately 6M monitored parameters. Using the experience of nearly two years of operation with beam the DCS automation software has been enhanced to increase the system efficiency. The automation allows now for configuration commands that can be used to automatically pre-configure hardwar...

  16. Cryogenic testing of the TPC superconducting solenoid

    International Nuclear Information System (INIS)

    Green, M.A.; Smits, R.G.; Taylor, J.D.

    1983-06-01

    This report describes the results of a series of tests on the TPC superconducting magnet cryogenic system which occurred during the winter and spring of 1983. The tests occurred at interaction region 2 of the PEP colliding beam facility at the Stanford Linear Accelerator Center (SLAC). The TPC Magnet Cryogenic System which was tested includes the following major components: a remote helium compressor with a full flow liquid nitrogen purification station, 400 meters of high pressure supply and low pressure return lines; and locally a CTi Model 2800 refrigerator with two Sulzer gas bearing turbines, the TPC magnet control dewar, 70 meters of transfer lines, and the TPC thin superconducting solenoid magnet. In addition, there is a conditioner (liquid nitrogen heat exchangers and gas heaters) system for cooldown and warmup of the magnet. This report describes the local cryogenic system and describes the various steps in the cooldown and operation of the TPC magnet. The tests were successful in that they showed that the TPC magnet could be cooled down in 24 hours and the magnet could be operated on the refrigerator or a helium pump with adequate cooling margin. The tests identified problems with the cryogenic system and the 2800 refrigerator. Procedures for successful operation and quenching of the superconducting magnet were developed. 19 references

  17. Detailed design of the ITER central solenoid

    International Nuclear Information System (INIS)

    Libeyre, P.; Mitchell, N.; Bessette, D.; Gribov, Y.; Jong, C.; Lyraud, C.

    2009-01-01

    The central solenoid (CS) of the ITER tokamak contributes to the inductive flux to drive the plasma, to the shaping of the field lines in the divertor region and to vertical stability control. It is made of 6 independent coils, using a Nb3Sn cable-in-conduit superconducting conductor, held together by a vertical precompression structure. This design enables ITER to access a wide operating window of plasma parameters, up to 17 MA and covering inductive and non-inductive operation. Each coil is based on a stack of multiple pancake winding units to minimise joints. A glass-polyimide electrical insulation, impregnated with epoxy resin, is giving a high voltage operating capability, tested up to 29 kV. The CS performance is fatigue driven mainly by the stress levels in the conductor jacket and in the precompression structure needed to keep the modules in contact during the repulsive forces which can arise in operation. A rigid connection to the TF coils provided at one end and a centering support at the other end allow to resist net vertical forces as well as unbalanced radial forces while avoiding torsion transmission from the TF Coils to the CS assembly.

  18. E-beam heated linear solenoid reactors

    International Nuclear Information System (INIS)

    Benford, J.; Bailey, V.; Oliver, D.

    1976-01-01

    A conceptual design and system analysis shows that electron beam heated linear solenoidal reactors are attractive for near term applications which can use low gain fusion sources. Complete plant designs have been generated for fusion based breeders of fissile fuel over a wide range of component parameters (e.g., magnetic fields, reactor lengths, plasma densities) and design options (e.g., various radial and axial loss mechanisms). It appears possible that a reactor of 100 to 300 meters length operating at power levels of 1000 MWt can economically produce 2000 to 8000 kg/yr of 233 U to supply light water reactor fuel needs beyond 2000 A.D. Pure fusion reactors of 300 to 500 meter lengths are possible. Physics and operational features of reactors are described. Beam heating by classical and anomalous energy deposition is reviewed. The technology of the required beams has been developed to MJ/pulse levels, within a factor of 20 of that needed for full scale production reactors. The required repetitive pulsing appears practical

  19. A solenoidal and monocusp ion source (SAMIS) (abstract)ab

    International Nuclear Information System (INIS)

    Burns, E.J.; Brainard, J.P.; Draper, C.H.; Ney, R.H.; Leung, K.N.; Perkins, L.T.; Williams, M.D.; Wilde, S.B.

    1996-01-01

    We have developed a new magnetic monocusp ion source for single aperture applications such as neutron generators. Coupling solenoidal magnetic fields on both sides of a monocusp magnetic field has generated over 70% atomic deuterium ions at pressures as low as 0.4 Pa (3 mTorr). This article describes the performance and characteristics of the solenoidal and monocusp ion source. copyright 1996 American Institute of Physics

  20. An Inexpensive Toroidal Solenoid for an Investigative Student Lab

    Science.gov (United States)

    Ferstl, Andrew; Broberg, John

    2008-09-01

    Magnetism and Ampère's law is a common subject in most calculus-based introductory physics courses. Many textbooks offer examples to calculate the magnetic field produced by a symmetric current by using Ampère's law. These examples include the solenoid and the toroidal solenoid (sometimes called a torus; see Fig. 1), which are used in many applications, including the study of plasmas.

  1. Asymmetric Effects on Escape Rates of Bistable System

    International Nuclear Information System (INIS)

    Wang Canjun; Mei Dongcheng; Dai Zucheng

    2011-01-01

    The asymmetric effects on the escape rates from the stable states x ± in the bistable system are analyzed. The results indicate that the multiplicative noise and the additive noise always enhance the particle escape from stable states x ± of bistable. However, the asymmetric parameter r enhances the particle escape from stable state x + , and holds back the particle escape from stable state x - . (general)

  2. Analytic descriptions of stochastic bistable systems under force ramp.

    Science.gov (United States)

    Friddle, Raymond W

    2016-05-01

    Solving the two-state master equation with time-dependent rates, the ubiquitous driven bistable system, is a long-standing problem that does not permit a complete solution for all driving rates. Here we show an accurate approximation to this problem by considering the system in the control parameter regime. The results are immediately applicable to a diverse range of bistable systems including single-molecule mechanics.

  3. Solenoid for Laser Induced Plasma Experiments at Janus

    Science.gov (United States)

    Klein, Sallee; Leferve, Heath; Kemp, Gregory; Mariscal, Derek; Rasmus, Alex; Williams, Jackson; Gillespie, Robb; Manuel, Mario; Kuranz, Carolyn; Keiter, Paul; Drake, R.

    2017-10-01

    Creating invariant magnetic fields for experiments involving laser induced plasmas is particularly challenging due to the high voltages at which the solenoid must be pulsed. Creating a solenoid resilient enough to survive through large numbers of voltage discharges, enabling it to endure a campaign lasting several weeks, is exceptionally difficult. Here we present a solenoid that is robust through 40 μs pulses at a 13 kV potential. This solenoid is a vast improvement over our previously fielded designs in peak magnetic field capabilities and robustness. Designed to be operated at small-scale laser facilities, the solenoid housing allows for versatility of experimental set-ups among diagnostic and target positions. Within the perpendicular field axis at the center there is 300 degrees of clearance which can be easily modified to meet the needs of a specific experiment, as well as an f/3 cone for transmitted or backscattered light. After initial design efforts, these solenoids are relatively inexpensive to manufacture.

  4. Does visual attention drive the dynamics of bistable perception?

    Science.gov (United States)

    Dieter, Kevin C; Brascamp, Jan; Tadin, Duje; Blake, Randolph

    2016-10-01

    How does attention interact with incoming sensory information to determine what we perceive? One domain in which this question has received serious consideration is that of bistable perception: a captivating class of phenomena that involves fluctuating visual experience in the face of physically unchanging sensory input. Here, some investigations have yielded support for the idea that attention alone determines what is seen, while others have implicated entirely attention-independent processes in driving alternations during bistable perception. We review the body of literature addressing this divide and conclude that in fact both sides are correct-depending on the form of bistable perception being considered. Converging evidence suggests that visual attention is required for alternations in the type of bistable perception called binocular rivalry, while alternations during other types of bistable perception appear to continue without requiring attention. We discuss some implications of this differential effect of attention for our understanding of the mechanisms underlying bistable perception, and examine how these mechanisms operate during our everyday visual experiences.

  5. A genetic bistable switch utilizing nonlinear protein degradation.

    Science.gov (United States)

    Huang, Daniel; Holtz, William J; Maharbiz, Michel M

    2012-07-09

    Bistability is a fundamental property in engineered and natural systems, conferring the ability to switch and retain states. Synthetic bistable switches in prokaryotes have mainly utilized transcriptional components in their construction. Using both transcriptional and enzymatic components, creating a hybrid system, allows for wider bistable parameter ranges in a circuit. In this paper, we demonstrate a tunable family of hybrid bistable switches in E. coli using both transcriptional components and an enzymatic component. The design contains two linked positive feedback loops. The first loop utilizes the lambda repressor, CI, and the second positive feedback loop incorporates the Lon protease found in Mesoplasma florum (mf-Lon). We experimentally tested for bistable behavior in exponential growth phase, and found that our hybrid bistable switch was able to retain its state in the absence of an input signal throughout 40 cycles of cell division. We also tested the transient behavior of our switch and found that switching speeds can be tuned by changing the expression rate of mf-Lon. To our knowledge, this work demonstrates the first use of dynamic expression of an orthogonal and heterologous protease to tune a nonlinear protein degradation circuit. The hybrid switch is potentially a more robust and tunable topology for use in prokaryotic systems.

  6. Genes contribute to the switching dynamics of bistable perception.

    Science.gov (United States)

    Shannon, Robert W; Patrick, Christopher J; Jiang, Yi; Bernat, Edward; He, Sheng

    2011-03-09

    Ordinarily, the visual system provides an unambiguous representation of the world. However, at times alternative plausible interpretations of a given stimulus arise, resulting in a dynamic perceptual alternation of the differing interpretations, commonly referred to as bistable or rivalrous perception. Recent research suggests that common neural mechanisms may be involved in the dynamics of very different types of bistable phenomena. Further, evidence has emerged that genetic factors may be involved in determining the rate of switch for at least one form of bistable perception, known as binocular rivalry. The current study evaluated whether genetic factors contribute to the switching dynamics for distinctly different variants of bistable perception in the same participant sample. Switching rates were recorded for MZ and DZ twin participants in two different bistable perception tasks, binocular rivalry and the Necker Cube. Strong concordance in switching rates across both tasks was evident for MZ but not DZ twins, indicating that genetic factors indeed contribute to the dynamics of multiple forms of bistable perception.

  7. The LASS [Larger Aperture Superconducting Solenoid] spectrometer

    International Nuclear Information System (INIS)

    Aston, D.; Awaji, N.; Barnett, B.

    1986-04-01

    LASS is the acronym for the Large Aperture Superconducting Solenoid spectrometer which is located in an rf-separated hadron beam at the Stanford Linear Accelerator Center. This spectrometer was constructed in order to perform high statistics studies of multiparticle final states produced in hadron reactions. Such reactions are frequently characterized by events having complicated topologies and/or relatively high particle multiplicity. Their detailed study requires a spectrometer which can provide good resolution in momentum and position over almost the entire solid angle subtended by the production point. In addition, good final state particle identification must be available so that separation of the many kinematically-overlapping final states can be achieved. Precise analyses of the individual reaction channels require high statistics, so that the spectrometer must be capable of high data-taking rates in order that such samples can be acquired in a reasonable running time. Finally, the spectrometer must be complemented by a sophisticated off-line analysis package which efficiently finds tracks, recognizes and fits event topologies and correctly associates the available particle identification information. This, together with complicated programs which perform specific analysis tasks such as partial wave analysis, requires a great deal of software effort allied to a very large computing capacity. This paper describes the construction and performance of the LASS spectrometer, which is an attempt to realize the features just discussed. The configuration of the spectrometer corresponds to the data-taking on K + and K - interactions in hydrogen at 11 GeV/c which took place in 1981 and 1982. This constitutes a major upgrade of the configuration used to acquire lower statistics data on 11 GeV/c K - p interactions during 1977 and 1978, which is also described briefly

  8. The LASS (Larger Aperture Superconducting Solenoid) spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Aston, D.; Awaji, N.; Barnett, B.; Bienz, T.; Bierce, R.; Bird, F.; Bird, L.; Blockus, D.; Carnegie, R.K.; Chien, C.Y.

    1986-04-01

    LASS is the acronym for the Large Aperture Superconducting Solenoid spectrometer which is located in an rf-separated hadron beam at the Stanford Linear Accelerator Center. This spectrometer was constructed in order to perform high statistics studies of multiparticle final states produced in hadron reactions. Such reactions are frequently characterized by events having complicated topologies and/or relatively high particle multiplicity. Their detailed study requires a spectrometer which can provide good resolution in momentum and position over almost the entire solid angle subtended by the production point. In addition, good final state particle identification must be available so that separation of the many kinematically-overlapping final states can be achieved. Precise analyses of the individual reaction channels require high statistics, so that the spectrometer must be capable of high data-taking rates in order that such samples can be acquired in a reasonable running time. Finally, the spectrometer must be complemented by a sophisticated off-line analysis package which efficiently finds tracks, recognizes and fits event topologies and correctly associates the available particle identification information. This, together with complicated programs which perform specific analysis tasks such as partial wave analysis, requires a great deal of software effort allied to a very large computing capacity. This paper describes the construction and performance of the LASS spectrometer, which is an attempt to realize the features just discussed. The configuration of the spectrometer corresponds to the data-taking on K and K interactions in hydrogen at 11 GeV/c which took place in 1981 and 1982. This constitutes a major upgrade of the configuration used to acquire lower statistics data on 11 GeV/c K p interactions during 1977 and 1978, which is also described briefly.

  9. Optimal region of latching activity in an adaptive Potts model for networks of neurons

    International Nuclear Information System (INIS)

    Abdollah-nia, Mohammad-Farshad; Saeedghalati, Mohammadkarim; Abbassian, Abdolhossein

    2012-01-01

    In statistical mechanics, the Potts model is a model for interacting spins with more than two discrete states. Neural networks which exhibit features of learning and associative memory can also be modeled by a system of Potts spins. A spontaneous behavior of hopping from one discrete attractor state to another (referred to as latching) has been proposed to be associated with higher cognitive functions. Here we propose a model in which both the stochastic dynamics of Potts models and an adaptive potential function are present. A latching dynamics is observed in a limited region of the noise(temperature)–adaptation parameter space. We hence suggest noise as a fundamental factor in such alternations alongside adaptation. From a dynamical systems point of view, the noise–adaptation alternations may be the underlying mechanism for multi-stability in attractor-based models. An optimality criterion for realistic models is finally inferred

  10. Latching device for securing a closure to a cask for transporting radioactive waste

    International Nuclear Information System (INIS)

    Obermeyer, F.D.; Cruz, R.R.; Bieberbach, G.

    1991-01-01

    This patent describes a latching device for removably securing and sealingly engaging a closure around an opening in a cask defined by an edge of the cask. It comprises: at least three shear key assemblies uniformly spaced around the outer portion of the closure, each of which includes a shear key means having a bolt portion movably mounted in the closure, and a latch portion that is insertable into and retractable out of a slot means in the cask edge in response to the application of a closing and an opening force applied to the bolt portion, at least one drive mechanism located within a cavity in the closure and connected to the bolt portion of the shear key assemblies for applying the closing and opening forces to the bolt portions

  11. Contribution to the study of the latch-up phenomenon in CMOS technologies

    International Nuclear Information System (INIS)

    Leroux, Charles

    1988-01-01

    The latch-up phenomenon is due to the presence of a parasite PNPN structure between a circuit supply and the ground. This structure may pass from its usual high impedance state to a low impedance state (few Ohms). The author reports the development of a test methodology able to identify this phenomenon. An analytic model has been developed which takes several issues into account: the three-dimensional aspect of resistances of this structure, the strong injection and its consequences. A new element is introduced which allows the phenomenon retention. This model without adjustment parameter gives good results with respect to experiment. A strategy of optimisation of these technologies with respect to the latch-up effect has also been defined. It leads to the production of a batch for which structures with a low insulation distance between sources of transistors of opposite type (four microns) display a hold voltage greater than the supply voltage (five volts) [fr

  12. Comparative research on “high currents” induced by single event latch-up and transient-induced latch-up

    International Nuclear Information System (INIS)

    Chen Rui; Han Jian-Wei; Zheng Han-Sheng; Yu Yong-Tao; Shangguang Shi-Peng; Feng Guo-Qiang; Ma Ying-Qi

    2015-01-01

    By using the pulsed laser single event effect facility and electro-static discharge (ESD) test system, the characteristics of the “high current”, relation with external stimulus and relevance to impacted modes of single event latch-up (SEL) and transient-induced latch-up (TLU) are studied, respectively, for a 12-bit complementary metal–oxide semiconductor (CMOS) analog-to-digital converter. Furthermore, the sameness and difference in physical mechanism between “high current” induced by SEL and that by TLU are disclosed in this paper. The results show that the minority carrier diffusion in the PNPN structure of the CMOS device which initiates the active parasitic NPN and PNP transistors is the common reason for the “high current” induced by SEL and for that by TLU. However, for SEL, the minority carrier diffusion is induced by the ionizing radiation, and an underdamped sinusoidal voltage on the supply node (the ground node) is the cause of the minority carrier diffusion for TLU. (paper)

  13. Bistable energy harvesting enhancement with an auxiliary linear oscillator

    Science.gov (United States)

    Harne, R. L.; Thota, M.; Wang, K. W.

    2013-12-01

    Recent work has indicated that linear vibrational energy harvesters with an appended degree-of-freedom (DOF) may be advantageous for introducing new dynamic forms to extend the operational bandwidth. Given the additional interest in bistable harvester designs, which exhibit a propitious snap through effect from one stable state to the other, it is a logical extension to explore the influence of an added DOF to a bistable system. However, bistable snap through is not a resonant phenomenon, which tempers the presumption that the dynamics induced by an additional DOF on bistable designs would inherently be beneficial as for linear systems. This paper presents two analytical formulations to assess the fundamental and superharmonic steady-state dynamics of an excited bistable energy harvester to which is attached an auxiliary linear oscillator. From an energy harvesting perspective, the model predicts that the additional linear DOF uniformly amplifies the bistable harvester response magnitude and generated power for excitation frequencies less than the attachment’s resonance while improved power density spans a bandwidth below this frequency. Analyses predict bandwidths having co-existent responses composed of a unique proportion of fundamental and superharmonic dynamics. Experiments validate key analytical predictions and observe the ability for the coupled system to develop an advantageous multi-harmonic interwell response when the initial conditions are insufficient for continuous high-energy orbit at the excitation frequency. Overall, the addition of an auxiliary linear oscillator to a bistable harvester is found to be an effective means of enhancing the energy harvesting performance and robustness.

  14. Improved StrongARM latch comparator: Design, analysis and performance evaluation

    KAUST Repository

    Almansouri, Abdullah Saud Mohammed

    2017-07-13

    This paper presents an improved StrongARM latch comparator, designed and simulated in 90nm and 32nm CMOS technologies. The proposed design provides an improvement of 7% in energy efficiency, 14% in speed and an average reduction of 41% in the clock feedthrough, compared to the conventional design. The new architecture also minimizes the area by reducing the required transistors needed for the enhanced performance.

  15. Latching and Declutching Control of the Solo Duck Wave-Energy Converter with Different Load Types

    Directory of Open Access Journals (Sweden)

    Jinming Wu

    2017-12-01

    Full Text Available The solo duck wave-energy converter (WEC captures power in a point absorber manner, hence it exhibits high power-capture efficiency within only a narrow bandwidth. Passive control is characterized by a unidirectional power flow, and thus its engineering implementation can be simplified. In this paper, two typical passive control strategies, latching and declutching control, are applied to the solo duck WEC to improve its power-capture performance at wave periods larger and smaller than the natural period of the WEC, respectively. Special attention is paid to the peak value of instantaneous WEC performance parameters, including the peak motion excursion, the peak power take-off (PTO moment, and the peak-to-average power ratio, when the captured power is maximized. Performance differences between the linear and coulomb loads are also investigated. Results show that both latching and declutching control can effectively improve captured power, but also incidentally increase the peak motion excursion and peak-to-average power ratio. When under latching and declutching control, the coulomb load leads to the same maximum relative capture width and peak motion excursion as the linear load, but presents smaller peak PTO moment and peak-to-average power ratio than the linear load, hence making the coulomb load the better choice for the solo duck WEC.

  16. A gate-latch-lock mechanism for hormone signalling by abscisic acid receptors

    KAUST Repository

    Melcher, Karsten

    2009-12-03

    Abscisic acid (ABA) is a ubiquitous hormone that regulates plant growth, development and responses to environmental stresses. Its action is mediated by the PYR/PYL/RCAR family of START proteins, but it remains unclear how these receptors bind ABA and, in turn, how hormone binding leads to inhibition of the downstream type 2C protein phosphatase (PP2C) effectors. Here we report crystal structures of apo and ABA-bound receptors as well as a ternary PYL2-ABA-PP2C complex. The apo receptors contain an open ligand-binding pocket flanked by a gate that closes in response to ABA by way of conformational changes in two highly conserved ?-loops that serve as a gate and latch. Moreover, ABA-induced closure of the gate creates a surface that enables the receptor to dock into and competitively inhibit the PP2C active site. A conserved tryptophan in the PP2C inserts directly between the gate and latch, which functions to further lock the receptor in a closed conformation. Together, our results identify a conserved gate-latch-lock mechanism underlying ABA signalling. © 2009 Macmillan Publishers Limited. All rights reserved.

  17. A gate-latch-lock mechanism for hormone signalling by abscisic acid receptors

    KAUST Repository

    Melcher, Karsten; Ng, Ley-Moy; Zhou, X. Edward; Soon, Fen-Fen; Xu, Yong; Suino-Powell, Kelly M.; Park, Sang-Youl; Weiner, Joshua J.; Fujii, Hiroaki; Chinnusamy, Viswanathan; Kovach, Amanda; Li, Jun; Wang, Yonghong; Li, Jiayang; Peterson, Francis C.; Jensen, Davin R.; Yong, Eu-Leong; Volkman, Brian F.; Cutler, Sean R.; Zhu, Jian-Kang; Xu, H. Eric

    2009-01-01

    Abscisic acid (ABA) is a ubiquitous hormone that regulates plant growth, development and responses to environmental stresses. Its action is mediated by the PYR/PYL/RCAR family of START proteins, but it remains unclear how these receptors bind ABA and, in turn, how hormone binding leads to inhibition of the downstream type 2C protein phosphatase (PP2C) effectors. Here we report crystal structures of apo and ABA-bound receptors as well as a ternary PYL2-ABA-PP2C complex. The apo receptors contain an open ligand-binding pocket flanked by a gate that closes in response to ABA by way of conformational changes in two highly conserved ?-loops that serve as a gate and latch. Moreover, ABA-induced closure of the gate creates a surface that enables the receptor to dock into and competitively inhibit the PP2C active site. A conserved tryptophan in the PP2C inserts directly between the gate and latch, which functions to further lock the receptor in a closed conformation. Together, our results identify a conserved gate-latch-lock mechanism underlying ABA signalling. © 2009 Macmillan Publishers Limited. All rights reserved.

  18. Bistable behaviour of biexciton population in a dense exciton-biexciton system in semiconductors

    International Nuclear Information System (INIS)

    Nguyen Ba An.

    1986-05-01

    The steady state bistable behaviour of biexciton population in a dense exciton-biexciton semiconductor is considered. The intrinsic optical feedback is provided by the recombination mechanism. The exciton-biexciton and biexciton-biexciton interactions play the role of non-linearity responsible for biexciton bistability to occur. The conditions leading to the effect of bistability are obtained and two-parameter phase transition diagrams are drawn for both intensity and frequency bistable phenomena. (author)

  19. Optical bistability induced by quantum coherence in a negative index atomic medium

    International Nuclear Information System (INIS)

    Zhang Hong-Jun; Sun Hui; Li Jin-Ping; Yin Bao-Yin; Guo Hong-Ju

    2013-01-01

    Bistability behaviors in an optical ring cavity filled with a dense V-type four-level atomic medium are theoretically investigated. It is found that the optical bistability can appear in the negative refraction frequency band, while both the bistability and multi-stability can occur in the positive refraction frequency bands. Therefore, optical bistability can be realized from conventional material to negative index material due to quantum coherence in our scheme. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  20. Evaluation of bistable systems versus matched filters in detecting bipolar pulse signals

    OpenAIRE

    Duan, Fabing; Abbott, Derek; Gao, Qisheng

    2004-01-01

    This paper presents a thorough evaluation of a bistable system versus a matched filter in detecting bipolar pulse signals. The detectability of the bistable system can be optimized by adding noise, i.e. the stochastic resonance (SR) phenomenon. This SR effect is also demonstrated by approximate statistical detection theory of the bistable system and corresponding numerical simulations. Furthermore, the performance comparison results between the bistable system and the matched filter show that...

  1. Lessons Learned for the MICE Coupling Solenoid from the MICE Spectrometer Solenoids

    International Nuclear Information System (INIS)

    Green, Michael A.; Wang, Li; Pan, Heng; Wu, Hong; Guo, Xinglong; Li, S.Y.; Zheng, S.X.; Virostek, Steve P.; DeMello, Allen J.; Li, Derun; Trillaud, Frederick; Zisman, Michael S.

    2010-01-01

    Tests of the spectrometer solenoids have taught us some important lessons. The spectrometer magnet lessons learned fall into two broad categories that involve the two stages of the coolers that are used to cool the magnets. On the first spectrometer magnet, the problems were centered on the connection of the cooler 2nd-stage to the magnet cold mass. On the first test of the second spectrometer magnet, the problems were centered on the cooler 1st-stage temperature and its effect on the operation of the HTS leads. The second time the second spectrometer magnet was tested; the cooling to the cold mass was still not adequate. The cryogenic designs of the MICE and MuCOOL coupling magnets are quite different, but the lessons learned from the tests of the spectrometer magnets have affected the design of the coupling magnets.

  2. Bistability and Biofilm Formation in Bacillus subtilis

    Science.gov (United States)

    Chai, Yunrong; Chu, Frances; Kolter, Roberto; Losick, Richard

    2008-01-01

    Summary Biofilms of Bacillus subtilis consist of long chains of cells that are held together in bundles by an extracellular matrix of exopolysaccharide and the protein TasA. The exopolysaccharide is produced by enzymes encoded by the epsA-O operon and the gene encoding TasA is located in the yqxM-sipW-tasA operon. Both operons are under the control of the repressor SinR. Derepression is mediated by the antirepressor SinI, which binds to SinR with a 1:1 stoichiometry. Paradoxically, in medium promoting derepression of the matrix operons, the overall concentration of SinR in the culture greatly exceeded that of SinI. We show that under biofilm-promoting conditions sinI, which is under the control of the response regulator Spo0A, was expressed only in a small subpopulation of cells, whereas sinR was expressed in almost all cells. Activation of Spo0A is known to be subject to a bistable switch, and we infer that SinI reaches levels sufficient to trigger matrix production only in the subpopulation of cells in which Spo0A is active. Additionally, evidence suggests that sinI is expressed at intermediate, but not low or high, levels of Spo0A activity, which may explain why certain nutritional conditions are more effective in promoting biofilm formation than others. PMID:18047568

  3. Bistability of mangrove forests and competition with freshwater plants

    Science.gov (United States)

    Jiang, Jiang; Fuller, Douglas O; Teh, Su Yean; Zhai, Lu; Koh, Hock Lye; DeAngelis, Donald L.; Sternberg, L.D.S.L.

    2015-01-01

    Halophytic communities such as mangrove forests and buttonwood hammocks tend to border freshwater plant communities as sharp ecotones. Most studies attribute this purely to underlying physical templates, such as groundwater salinity gradients caused by tidal flux and topography. However, a few recent studies hypothesize that self-reinforcing feedback between vegetation and vadose zone salinity are also involved and create a bistable situation in which either halophytic dominated habitat or freshwater plant communities may dominate as alternative stable states. Here, we revisit the bistability hypothesis and demonstrate the mechanisms that result in bistability. We demonstrate with remote sensing imagery the sharp boundaries between freshwater hardwood hammock communities in southern Florida and halophytic communities such as buttonwood hammocks and mangroves. We further document from the literature how transpiration of mangroves and freshwater plants respond differently to vadose zone salinity, thus altering the salinity through feedback. Using mathematical models, we show how the self-reinforcing feedback, together with physical template, controls the ecotones between halophytic and freshwater communities. Regions of bistability along environmental gradients of salinity have the potential for large-scale vegetation shifts following pulse disturbances such as hurricane tidal surges in Florida, or tsunamis in other regions. The size of the region of bistability can be large for low-lying coastal habitat due to the saline water table, which extends inland due to salinity intrusion. We suggest coupling ecological and hydrologic processes as a framework for future studies.

  4. Fundamental role of bistability in optimal homeostatic control

    Science.gov (United States)

    Wang, Guanyu

    2013-03-01

    Bistability is a fundamental phenomenon in nature and has a number of fine properties. However, these properties are consequences of bistability at the physiological level, which do not explain why it had to emerge during evolution. Using optimal homeostasis as the first principle and Pontryagin's Maximum Principle as the optimization approach, I find that bistability emerges as an indispensable control mechanism. Because the mathematical model is general and the result is independent of parameters, it is likely that most biological systems use bistability to control homeostasis. Glucose homeostasis represents a good example. It turns out that bistability is the only solution to a dilemma in glucose homeostasis: high insulin efficiency is required for rapid plasma glucose clearance, whereas an insulin sparing state is required to guarantee the brain's safety during fasting. This new perspective can illuminate studies on the twin epidemics of obesity and diabetes and the corresponding intervening strategies. For example, overnutrition and sedentary lifestyle may represent sudden environmental changes that cause the lose of optimality, which may contribute to the marked rise of obesity and diabetes in our generation.

  5. Dynamic control of a bistable wing under aerodynamic loading

    International Nuclear Information System (INIS)

    Bilgen, Onur; Arrieta, Andres F; Friswell, Michael I; Hagedorn, Peter

    2013-01-01

    The aerodynamic evaluation of a dynamic control technique applied to a bistable unsymmetrical cross-ply composite plate with surface bonded piezoelectric actuators is presented. The plate is clamped on one end to form a low-aspect-ratio wing. A previously proposed dynamic control method, utilizing bending resonance in different stable equilibrium positions, is used to induce snap-through between the two equilibrium states. Compared to quasi-static actuation, driving the bistable plate near resonance using surface bonded piezoelectric materials requires, theoretically, a lower peak excitation voltage to achieve snap-through. First, a set of extensive wind tunnel experiments are conducted on the passive bistable wing to understand the change in the dynamic behavior under various aerodynamic conditions. The passive wing demonstrated sufficient bending stiffness to sustain its shape under aerodynamic loading while preserving the desired bistable behavior. Next, by the use of the resonant control technique, the plate is turned into an effectively monostable structure, or alternatively, both stable equilibrium positions can be reached actively from the other stable equilibrium. Dynamic forward and reverse snap-through is demonstrated in the wind tunnel which shows both the effectiveness of the piezoelectric actuation as well as the load carrying capability of both states of the bistable wing. (paper)

  6. Oscillations in the bistable regime of neuronal networks.

    Science.gov (United States)

    Roxin, Alex; Compte, Albert

    2016-07-01

    Bistability between attracting fixed points in neuronal networks has been hypothesized to underlie persistent activity observed in several cortical areas during working memory tasks. In network models this kind of bistability arises due to strong recurrent excitation, sufficient to generate a state of high activity created in a saddle-node (SN) bifurcation. On the other hand, canonical network models of excitatory and inhibitory neurons (E-I networks) robustly produce oscillatory states via a Hopf (H) bifurcation due to the E-I loop. This mechanism for generating oscillations has been invoked to explain the emergence of brain rhythms in the β to γ bands. Although both bistability and oscillatory activity have been intensively studied in network models, there has not been much focus on the coincidence of the two. Here we show that when oscillations emerge in E-I networks in the bistable regime, their phenomenology can be explained to a large extent by considering coincident SN and H bifurcations, known as a codimension two Takens-Bogdanov bifurcation. In particular, we find that such oscillations are not composed of a stable limit cycle, but rather are due to noise-driven oscillatory fluctuations. Furthermore, oscillations in the bistable regime can, in principle, have arbitrarily low frequency.

  7. Non-resonant energy harvesting via an adaptive bistable potential

    International Nuclear Information System (INIS)

    Hosseinloo, Ashkan Haji; Turitsyn, Konstantin

    2016-01-01

    Narrow bandwidth and easy detuning, inefficiency in broadband and non-stationary excitations, and difficulties in matching a linear harvester’s resonance frequency to low-frequency excitations at small scales, have convinced researchers to investigate nonlinear, and in particular bistable, energy harvesters in recent years. However, bistable harvesters suffer from co-existing low and high energy orbits, and sensitivity to initial conditions, and have recently been proven inefficient when subjected to many real-world random and non-stationary excitations. Here, we propose a novel non-resonant buy-low-sell-high strategy that can significantly improve the harvester’s effectiveness at low frequencies in a much more robust fashion. This strategy could be realized by a passive adaptive bistable system. Simulation results confirm the high effectiveness of the adaptive bistable system following a buy-low-sell-high logic when subjected to harmonic and random non-stationary walking excitations compared to its conventional bistable and linear counterparts. (paper)

  8. Chaos in a new bistable rotating electromechanical system

    International Nuclear Information System (INIS)

    Tsapla Fotsa, R.; Woafo, P.

    2016-01-01

    Highlights: • A new electromechanical system with rotating arm and bistable potential energy is studied. • The bistability is generated by the interaction of three permanent magnets, one fixed at the end of the arm and two other fixed at equal distance relative to the central position of the arm. • It exhibits dissipative and Hamiltonian chaos. • Such a bistable electromechanical system can be used as the actuation part of chaotic sieves and mixers. - Abstract: A device consisting of an induction motor activating a rotating rigid arm is designed and comprises a bistable potential due to the presence of three permanent magnets. Its mathematical equations are established and the numerical results both in the absence and in the presence of magnets are compared. The generation of chaotic behavior is achieved using two different external excitations: sinewave and square wave. In the presence of magnets, the system presents periodic and dissipative chaotic dynamics. Approximating the global potential energy to a bistable quartic potential, the Melnikov method is used to derive the conditions for the appearance of Hamiltonian chaos. Such a device can be used for industrial and domestic applications for mixing and sieving activities.

  9. Frontoparietal cortex mediates perceptual transitions in bistable perception.

    Science.gov (United States)

    Weilnhammer, Veith A; Ludwig, Karin; Hesselmann, Guido; Sterzer, Philipp

    2013-10-02

    During bistable vision, perception oscillates between two mutually exclusive percepts despite constant sensory input. Greater BOLD responses in frontoparietal cortex have been shown to be associated with endogenous perceptual transitions compared with "replay" transitions designed to closely match bistability in both perceptual quality and timing. It has remained controversial, however, whether this enhanced activity reflects causal influences of these regions on processing at the sensory level or, alternatively, an effect of stimulus differences that result in, for example, longer durations of perceptual transitions in bistable perception compared with replay conditions. Using a rotating Lissajous figure in an fMRI experiment on 15 human participants, we controlled for potential confounds of differences in transition duration and confirmed previous findings of greater activity in frontoparietal areas for transitions during bistable perception. In addition, we applied dynamic causal modeling to identify the neural model that best explains the observed BOLD signals in terms of effective connectivity. We found that enhanced activity for perceptual transitions is associated with a modulation of top-down connectivity from frontal to visual cortex, thus arguing for a crucial role of frontoparietal cortex in perceptual transitions during bistable perception.

  10. Numerical and experimental study of bistable plates for morphing structures

    Science.gov (United States)

    Nicassio, F.; Scarselli, G.; Avanzini, G.; Del Core, G.

    2017-04-01

    This study is concerned with the activation energy threshold of bistable composite plates in order to tailor a bistable system for specific aeronautical applications. The aim is to explore potential configurations of the bistable plates and their dynamic behavior for designing novel morphing structure suitable for aerodynamic surfaces and, as a possible further application, for power harvesters. Bistable laminates have two stable mechanical shapes that can withstand aerodynamic loads without additional constraint forces or locking mechanisms. This kind of structures, when properly loaded, snap-through from one stable configuration to another, causing large strains that can also be used for power harvesting scopes. The transition between the stable states of the composite laminate can be triggered, in principle, simply by aerodynamic loads (pilot, disturbance or passive inputs) without the need of servo-activated control systems. Both numerical simulations based on Finite Element models and experimental testing based on different activating forcing spectra are used to validate this concept. The results show that dynamic activation of bistable plates depend on different parameters that need to be carefully managed for their use as aircraft passive wing flaps.

  11. A bistable mechanism for chord extension morphing rotors

    Science.gov (United States)

    Johnson, Terrence; Frecker, Mary; Gandhi, Farhan

    2009-03-01

    Research efforts have shown that helicopter rotor blade morphing is an effective means to improve flight performance. Previous example of rotor blade morphing include using smart-materials for trailing deflection and rotor blade twist and tip twist, the development of a comfortable airfoil using compliant mechanisms, the use of a Gurney flap for air-flow deflection and centrifugal force actuated device to increase the span of the blade. In this paper we explore the use of a bistable mechanism for rotor morphing, specifically, blade chord extension using a bistable arc. Increasing the chord of the rotor blade is expected to generate more lift-load and improve helicopter performance. Bistable or "snap through" mechanisms have multiple stable equilibrium states and are a novel way to achieve large actuation output stroke. Bistable mechanisms do not require energy input to maintain a stable equilibrium state as both states do not require locking. In this work, we introduce a methodology for the design of bistable arcs for chord morphing using the finite element analysis and pseudo-rigid body model, to study the effect of different arc types, applied loads and rigidity on arc performance.

  12. The derivation of a bistable criterion for double V-beam mechanisms

    International Nuclear Information System (INIS)

    Wu, Cho-Chun; Chen, Rongshun; Lin, Meng-Ju

    2013-01-01

    This study presents the theoretical derivation of the discriminant D as a structural and material criterion for determining whether bistability can occur in micromechanically bistable mechanisms. When D < 0, the mechanism displays bistable behavior if an appropriate force is applied to push the bistable mechanism, whereas when D > 0, bistable behavior cannot occur. The proposed V-beam bistable mechanism was successfully fabricated with various beam lengths and tilted angles. The experiments conducted in this study validated the theoretical study of bistability. A comparison of the theoretical solutions and experimental results shows good agreement. Results further show that to design a bistable V-beam mechanism, the tilted angle should be larger for the same beam length, whereas the beam length should be longer for the same tilted angle. The developed discriminant D can be used to predict if a bistable mechanism can achieve bistable behavior based on structural sizes and material properties. Consequently, researchers can reduce trial-and-error experiments when designing a bistable mechanism. A V-beam with a larger tilted angle of up to 5° was successfully fabricated to act as a bistable mechanism, compared to a 3.5° tilted angle in existing studies. Consequently, the proposed method has the advantages of shorter beam lengths and smaller device areas. (paper)

  13. Bistable near field and bistable transmittance in 2D composite slab consisting of nonlocal core-Kerr shell inclusions.

    Science.gov (United States)

    Huang, Yang; Wu, Ya Min; Gao, Lei

    2017-01-23

    We carry out a theoretical study on optical bistability of near field intensity and transmittance in two-dimensional nonlinear composite slab. This kind of 2D composite is composed of nonlocal metal/Kerr-type dielectric core-shell inclusions randomly embedded in the host medium, and we derivate the nonlinear relation between the field intensity in the shell of inclusions and the incident field intensity with self-consistent mean field approximation. Numerical demonstration has been performed to show the viable parameter space for the bistable near field. We show that nonlocality can provide broader region in geometric parameter space for bistable near field as well as bistable transmittance of the nonlocal composite slab compared to local case. Furthermore, we investigate the bistable transmittance in wavelength spectrum, and find that besides the input intensity, the wavelength operation could as well make the transmittance jump from a high value to a low one. This kind of self-tunable nano-composite slab might have potential application in optical switching devices.

  14. A Cryogenic Test Stand for Large Superconducting Solenoid Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Rabehl, R. [Fermilab; Carcagno, R. [Fermilab; Nogiec, J. [Fermilab; Orris, D. [Fermilab; Soyars, W. [Fermilab; Sylvester, C. [Fermilab

    2013-01-01

    A new test stand for testing large superconducting solenoid magnets at the Fermilab Central Helium Liquifier (CHL) has been designed, and operated. This test stand has been used to test a coupling coil for the Muon Ionization Cooling Experiment (MICE), and future uses include solenoids for the Fermilab mu2e experiment. This paper describes the test stand design and operation including controlled cool-down and warm-up. Overviews of the process controls system and the quench management system are also included.

  15. Dispersion in a bent-solenoid channel with symmetric focusing

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chun-xi [Argonne National Lab. (ANL), Argonne, IL (United States)

    2001-08-21

    Longitudinal ionization cooling of a muon beam is essential for muon colliders and will be useful for neutrino factories. Bent-solenoid channels with symmetric focusing has been considered for beam focusing and for generating the required dispersion in the ``emittance exchange'' scheme of longitudinal cooling. In this paper, we derive the Hamiltonian that governs the linear beam dynamics of a bent-solenoid channel, solve the single-particle dynamics, and give equations for determining the lattice functions, in particular, the dispersion functions.

  16. Operating experience feedback report - Solenoid-operated valve problems

    International Nuclear Information System (INIS)

    Ornstein, H.L.

    1991-02-01

    This report highlights significant operating events involving observed or potential common-mode failures of solenoid-operated valves (SOVs) in US plants. These events resulted in degradation or malfunction of multiple trains of safety systems as well as of multiple safety systems. On the basis of the evaluation of these events, the Office for Analysis and Evaluation of Operational Data (AEOD) of the US Nuclear Regulatory Commission (NRC) concludes that the problems with solenoid-operated valves are an important issue that needs additional NRC and industry attention. This report also provides AEOD's recommendations for actions to reduce the occurrence of SOV common-mode failures. 115 refs., 7 figs., 2 tabs

  17. Laser solenoid: an alternate use of lasers in fusion power

    International Nuclear Information System (INIS)

    Rose, P.H.

    1977-01-01

    A unique laser assisted fusion approach is under development at Mathematical Sciences Northwest, Inc. (MSNW). This approach captures one of the most developed aspects of high energy laser technology, the efficient, large, scalable, pulsed electron beam initiated, electric discharge, CO 2 infrared laser. This advanced technology is then combined with the simple geometry of a linear magnetic confinement system. The laser solenoid concept will be described, current work and experimental progress will be discussed, and the technological problems of building such a system will be assessed. Finally a comparison will be made of the technology and economics for the laser solenoid and alternative fusion approaches

  18. Optical Bistability in Graded Core-Shell Granular Composites

    International Nuclear Information System (INIS)

    Wu Ya-Min; Chen Guo-Qing; Xue Si-Zhong; Zhu Zhuo-Wei; Ma Chao-Qun

    2012-01-01

    The intrinsic optical bistability (OB) of graded core-shell granular composites is investigated. The coated particles are made of cores with gradient dielectric function in c (r) = A(r/a) k and nonlinear shells. In view of the exponential distribution of the core dielectric constant, the potential functions of each region are obtained by solving the Maxwell equations, and the mathematical expressions of electric field in the shells and cores are determined. Numerical study reveals that the optical bistable threshold and the threshold width of the composite medium are dependent on the shell thickness, core dielectric exponent, and power function coefficient. The optical bistable width increases with the decreasing shell thickness and the power exponent and with the increasing power function coefficient

  19. Bistable cholesteric liquid crystal light shutter with multielectrode driving.

    Science.gov (United States)

    Li, Cheng-Chang; Tseng, Heng-Yi; Pai, Tsung-Wei; Wu, Yu-Ching; Hsu, Wen-Hao; Jau, Hung-Chang; Chen, Chun-Wei; Lin, Tsung-Hsien

    2014-08-01

    An electrically activated bistable light shutter that exploits polymer-stabilized cholesteric liquid crystal film was developed. Under double-sided three-terminal electrode driving, the device can be bistable and switched between focal conic and homeotropic textures with a uniform in-plane and vertical electrical field. The transparent state with a transmittance of 80% and the opaque/scattering state with a transmittance of 13% can be realized without any optical compensation film, and each can be simply switched to the other by applying a pulse voltage. Also, gray-scale selection can be performed by varying the applied voltage. The designed energy-saving bistable light shutter can be utilized to preserve privacy and control illumination and the flow of energy.

  20. The Compact Muon Solenoid Heavy Ion program

    International Nuclear Information System (INIS)

    Yepes, Pablo

    2005-01-01

    The Pb-Pb center of mass energy at the LHC will exceed that of Au-Au collisions at RHIC (Relativistic Heavy Ion Collider) by nearly a factor of 30, providing exciting opportunities for addressing unique physics issues in a completely new energy domain. The interest of the Heavy Ion (HI) Physics at LHC is discussed in more detail in the LHC-USA white paper and the Compact Muon Solenoid (CMS) Heavy Ion proposal. A few highlights are presented in this document. Heavy ion collisions at LHC energies will explore regions of energy and particle density significantly beyond those reachable at RHIC. The energy density of the thermalized matter created at the LHC is estimated to be 20 times higher than at RHIC, implying an initial temperature, which is greater than at RHIC by more than a factor of two. The higher density of produced partons also allows a faster thermalization. As a consequence, the ratio of the quark-gluon plasma lifetime to the thermalization time increases by a factor of 10 over RHIC. Thus the hot, dense systems created in HI collisions at the LHC spend most of the time in a purely partonic state. The longer lifetime of the quark-gluon plasma state widens significantly the time window available to probe it experimentally. RHIC experiments have reported evidence for jet production in HI collisions and for suppression of high p T particle production. Those results open a new field of exploration of hot and dense nuclear matter. Even though RHIC has already broken ground, the production rates for jets with p T > 30 GeV are several orders of magnitude larger at the LHC than at RHIC, allowing for systematic studies with high statistics in a clean kinematic region. High p T quark and gluon jets can be used to study the hot hadronic medium produced in HI interactions. The larger Q 2 causes jets to materialize very soon after the collision. They are thus embedded in and propagate through the dense environment as it forms and evolves. Through their interactions

  1. Design of a bistable switch to control cellular uptake.

    Science.gov (United States)

    Oyarzún, Diego A; Chaves, Madalena

    2015-12-06

    Bistable switches are widely used in synthetic biology to trigger cellular functions in response to environmental signals. All bistable switches developed so far, however, control the expression of target genes without access to other layers of the cellular machinery. Here, we propose a bistable switch to control the rate at which cells take up a metabolite from the environment. An uptake switch provides a new interface to command metabolic activity from the extracellular space and has great potential as a building block in more complex circuits that coordinate pathway activity across cell cultures, allocate metabolic tasks among different strains or require cell-to-cell communication with metabolic signals. Inspired by uptake systems found in nature, we propose to couple metabolite import and utilization with a genetic circuit under feedback regulation. Using mathematical models and analysis, we determined the circuit architectures that produce bistability and obtained their design space for bistability in terms of experimentally tuneable parameters. We found an activation-repression architecture to be the most robust switch because it displays bistability for the largest range of design parameters and requires little fine-tuning of the promoters' response curves. Our analytic results are based on on-off approximations of promoter activity and are in excellent qualitative agreement with simulations of more realistic models. With further analysis and simulation, we established conditions to maximize the parameter design space and to produce bimodal phenotypes via hysteresis and cell-to-cell variability. Our results highlight how mathematical analysis can drive the discovery of new circuits for synthetic biology, as the proposed circuit has all the hallmarks of a toggle switch and stands as a promising design to control metabolic phenotypes across cell cultures. © 2015 The Author(s).

  2. Excitonic bistabilities, instabilities and chaos in laser-pumped semiconductor

    International Nuclear Information System (INIS)

    Nguyen Ba An; Nguyen Trung Dan; Hoang Xuan Nguyen

    1992-07-01

    The Hurwitz criteria are used for a stability analysis of the steady state excitonic optical bistability curves in a semiconductor pumped by an external laser resonant with the exciton level. Besides the middle branch of the bistability curves which is unstable in the sense of the linear stability theory, we have found other domains of instability in the upper and lower branches of the steady state curves. Numerical results show that a possible route to chaos in the photon-exciton system is period-doubling self-oscillation process. The influence of the presence of free carriers that coexist with the excitons is also discussed. (author). 16 refs, 6 figs

  3. Large-Scale Analysis of Network Bistability for Human Cancers

    Science.gov (United States)

    Shiraishi, Tetsuya; Matsuyama, Shinako; Kitano, Hiroaki

    2010-01-01

    Protein–protein interaction and gene regulatory networks are likely to be locked in a state corresponding to a disease by the behavior of one or more bistable circuits exhibiting switch-like behavior. Sets of genes could be over-expressed or repressed when anomalies due to disease appear, and the circuits responsible for this over- or under-expression might persist for as long as the disease state continues. This paper shows how a large-scale analysis of network bistability for various human cancers can identify genes that can potentially serve as drug targets or diagnosis biomarkers. PMID:20628618

  4. An Optically Driven Bistable Janus Rotor with Patterned Metal Coatings.

    Science.gov (United States)

    Zong, Yiwu; Liu, Jing; Liu, Rui; Guo, Honglian; Yang, Mingcheng; Li, Zhiyuan; Chen, Ke

    2015-11-24

    Bistable rotation is realized for a gold-coated Janus colloidal particle in an infrared optical trap. The metal coating on the Janus particles are patterned by sputtering gold on a monolayer of closely packed polystyrene particles. The Janus particle is observed to stably rotate in an optical trap. Both the direction and the rate of rotation can be experimentally controlled. Numerical calculations reveal that the bistable rotation is the result of spontaneous symmetry breaking induced by the uneven curvature of the coating patterns on the Janus sphere. Our results thus provide a simple method to construct large quantities of fully functional rotary motors for nano- or microdevices.

  5. Excitonic optical bistability in n-type doped semiconductors

    International Nuclear Information System (INIS)

    Nguyen Ba An; Le Thi Cat Tuong

    1991-07-01

    A resonant monochromatic pump laser generates coherent excitons in an n-type doped semiconductor. Both exciton-exciton and exciton-donor interactions come into play. The former interaction can give rise to the appearance of optical bistability which is heavily influenced by the latter one. When optical bistability occurs at a fixed laser frequency both its holding intensity and hysteresis loop size are shown to decrease with increasing donor concentration. Two possibilities are suggested for experimentally determining one of the two parameters of the system - the exciton-donor coupling constant and the donor concentration, if the other parameter is known beforehand. (author). 36 refs, 2 figs

  6. The Necker-Zeno model for bistable perception.

    Science.gov (United States)

    Atmanspacher, Harald; Filk, Thomas

    2013-10-01

    A novel conceptual framework for theoretical psychology is presented and illustrated for the example of bistable perception. A basic formal feature of this framework is the non-commutativity of operations acting on mental states. A corresponding model for the bistable perception of ambiguous stimuli, the Necker-Zeno model, is sketched and some empirical evidence for it so far is described. It is discussed how a temporal non-locality of mental states, predicted by the model, can be understood and tested. © 2013 Cognitive Science Society, Inc.

  7. Energy losses in the D0 β solenoid cryostat caused by current changes

    International Nuclear Information System (INIS)

    Visser, A.T.

    1993-11-01

    The proposed D0 β solenoid is a superconducting solenoid mounted inside an aluminum tube which supports the solenoid winding over it's full length. This aluminum support tube, also called bobbin, is therefore very tightly coupled to magnetic flux changes caused by solenoid current variations. These current changes in the solenoid, will cause answer currents to flow in the resistive bobbin wall and therefore cause heat losses. The insertion of an external dump resistor in the solenoid current loop reduces energy dissipation inside the cryostat during a quench and will shorten the discharge time constant. This note presents a simple electrical model for the coupled bobbin and solenoid and makes it easier to understand the circuit behavior and losses. Estimates for the maximum allowable rate of solenoid current changes, based on the maximum permissible rate of losses can be made using this model

  8. THE DENSITY DISTRIBUTION IN TURBULENT BISTABLE FLOWS

    International Nuclear Information System (INIS)

    Gazol, Adriana; Kim, Jongsoo

    2013-01-01

    We numerically study the volume density probability distribution function (n-PDF) and the column density probability distribution function (Σ-PDF) resulting from thermally bistable turbulent flows. We analyze three-dimensional hydrodynamic models in periodic boxes of 100 pc by side, where turbulence is driven in the Fourier space at a wavenumber corresponding to 50 pc. At low densities (n ∼ –3 ), the n-PDF is well described by a lognormal distribution for an average local Mach number ranging from ∼0.2 to ∼5.5. As a consequence of the nonlinear development of thermal instability (TI), the logarithmic variance of the distribution of the diffuse gas increases with M faster than in the well-known isothermal case. The average local Mach number for the dense gas (n ∼> 7.1 cm –3 ) goes from ∼1.1 to ∼16.9 and the shape of the high-density zone of the n-PDF changes from a power law at low Mach numbers to a lognormal at high M values. In the latter case, the width of the distribution is smaller than in the isothermal case and grows slower with M. At high column densities, the Σ-PDF is well described by a lognormal for all of the Mach numbers we consider and, due to the presence of TI, the width of the distribution is systematically larger than in the isothermal case but follows a qualitatively similar behavior as M increases. Although a relationship between the width of the distribution and M can be found for each one of the cases mentioned above, these relations are different from those of the isothermal case.

  9. Electrical bistabilities and memory stabilities of nonvolatile bistable devices fabricated utilizing C60 molecules embedded in a polymethyl methacrylate layer

    International Nuclear Information System (INIS)

    Cho, Sung Hwan; Lee, Dong Ik; Jung, Jae Hun; Kim, Tae Whan

    2009-01-01

    Current-voltage (I-V) measurements on Al/fullerene (C 60 ) molecules embedded in polymethyl methacrylate/Al devices at 300 K showed a current bistability due to the existence of the C 60 molecules. The on/off ratio of the current bistability for the memory devices was as large as 10 3 . The retention time of the devices was above 2.5 x 10 4 s at room temperature, and cycling endurance tests on these devices indicated that the ON and OFF currents showed no degradation until 50 000 cycles. Carrier transport mechanisms for the nonvolatile bistable devices are described on the basis of the I-V experimental and fitting results.

  10. Bistable flow spectral analysis. Repercussions on jet pumps

    International Nuclear Information System (INIS)

    Gavilan Moreno, C.J.

    2011-01-01

    Highlights: → The most important thing in this paper, is the spectral characterization of the bistable flow in a Nuclear Power Plant. → This paper goes deeper in the effect of the bistable flow over the jet pump and the induced vibrations. → The jet pump frequencies are very close to natural jet pump frequencies, in the 3rd and 6th mode. - Abstract: There have been many attempts at characterizing and predicting bistable flow in boiling water reactors (BWRs). Nevertheless, in most cases the results have only managed to develop models that analytically reproduce the phenomenon (). Modeling has been forensic in all cases, while the capacity of the model focus on determining the exclusion areas on the recirculation flow map. The bistability process is known by its effects given there is no clear definition of its causal process. In the 1980s, Hitachi technicians () managed to reproduce bistable flow in the laboratory by means of pipe geometry, similar to that which is found in recirculation loops. The result was that the low flow pattern is formed by the appearance of a quasi stationary, helicoidal vortex in the recirculation collector's branches. This vortex creates greater frictional losses than regions without vortices, at the same discharge pressure. Neither the behavior nor the dynamics of these vortices were characterized in this paper. The aim of this paper is to characterize these vortices in such a way as to enable them to provide their own frequencies and their later effect on the jet pumps. The methodology used in this study is similar to the one used previously when analyzing the bistable flow in tube arrays with cross flow (). The method employed makes use of the power spectral density function. What differs is the field of application. We will analyze a Loop B with a bistable flow and compare the high and low flow situations. The same analysis will also be carried out on the loop that has not developed the bistable flow (Loop A) at the same moments

  11. Two optical bistability domains in composites of metal nanoparticles with nonlinear dielectric core

    Energy Technology Data Exchange (ETDEWEB)

    Shewamare, Sisay, E-mail: sisayshewa20@yahoo.com [Department of Physics, Addis Ababa University, P.O. Box 1176, Addis Ababa (Ethiopia); Mal' nev, V.N., E-mail: vadimnmalnev@yahoo.com [Department of Physics, Addis Ababa University, P.O. Box 1176, Addis Ababa (Ethiopia)

    2012-12-15

    It is shown that the local field in metal spherical particles with a dielectric core in an external varying electric field has two maxima at two different frequencies. The second maximum becomes more important with an increment in the metal fraction. Due to the nonlinear dielectric function of the core, the composite of these inclusions may have two optically induced bistability domains at different frequencies. At rather high metal fraction, two bistability domains merge and form one entire bistability domain. The parameters of these domains are studied numerically. The paper focuses on the second bistability domain, which has not been discussed in the literature so far. This domain exists in a comparatively narrow frequency range and its onset fields are lower than those of the first bistability domain. The lowest bistability onset fields are obtained in the entire domain. This peculiarity of the optical induced bistability in the metal composite with small dielectric cores can be attractive for possible applications.

  12. Controllable optical bistability in a three-mode optomechanical system with atom-cavity-mirror couplings

    Science.gov (United States)

    Chen, Bin; Wang, Xiao-Fang; Yan, Jia-Kai; Zhu, Xiao-Fei; Jiang, Cheng

    2018-01-01

    We theoretically investigate the optical bistable behavior in a three-mode optomechanical system with atom-cavity-mirror couplings. The effects of the cavity-pump detuning and the pump power on the bistable behavior are discussed detailedly, the impacts of the atom-pump detuning and the atom-cavity coupling strength on the bistability of the system are also explored, and the influences of the cavity-resonator coupling strength and the cavity decay rate are also taken into consideration. The numerical results demonstrate that by tuning these parameters the bistable behavior of the system can be freely switched on or off, and the threshold of the pump power for the bistability as well as the bistable region width can also be effectively controlled. These results can find potential applications in optical bistable switch in the quantum information processing.

  13. Two optical bistability domains in composites of metal nanoparticles with nonlinear dielectric core

    International Nuclear Information System (INIS)

    Shewamare, Sisay; Mal'nev, V.N.

    2012-01-01

    It is shown that the local field in metal spherical particles with a dielectric core in an external varying electric field has two maxima at two different frequencies. The second maximum becomes more important with an increment in the metal fraction. Due to the nonlinear dielectric function of the core, the composite of these inclusions may have two optically induced bistability domains at different frequencies. At rather high metal fraction, two bistability domains merge and form one entire bistability domain. The parameters of these domains are studied numerically. The paper focuses on the second bistability domain, which has not been discussed in the literature so far. This domain exists in a comparatively narrow frequency range and its onset fields are lower than those of the first bistability domain. The lowest bistability onset fields are obtained in the entire domain. This peculiarity of the optical induced bistability in the metal composite with small dielectric cores can be attractive for possible applications.

  14. 2 T superconducting detector solenoid for the PANDA target spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Efremov, A.A.; Koshurnikov, E.K. [Joint Institute for Nuclear Research, High Energy Physics Laboratory, Joliot-Curie, 6, 141980 Dubna, Moscow Region (Russian Federation); Lobanov, Y.Y. [Joint Institute for Nuclear Research, High Energy Physics Laboratory, Joliot-Curie, 6, 141980 Dubna, Moscow Region (Russian Federation)], E-mail: lobanov@jinr.ru; Makarov, A.F. [Joint Institute for Nuclear Research, High Energy Physics Laboratory, Joliot-Curie, 6, 141980 Dubna, Moscow Region (Russian Federation); Orth, H. [Gesellschaft fuer Schwerionenforschung, Planckstrasse 1, D-64291, Darmstadt (Germany); Sissakian, A.N.; Vodopianov, A.S. [Joint Institute for Nuclear Research, High Energy Physics Laboratory, Joliot-Curie, 6, 141980 Dubna, Moscow Region (Russian Federation)

    2008-02-01

    This paper describes the JINR design of the large 2 T superconducting solenoid for the target spectrometer of the PANDA experiment at HESR (FAIR, GSI, Darmstadt, Germany). The solenoid coil has an inner radius of 1.08 m and a length of 2.90 m. This solenoid is non-centrally split providing a warm bore of 100 mm in diameter through the coil to accommodate sufficient space for the internal target installations. Maximally stored energy in the windings is 22.3 MJ. All tracking and calorimetric detectors surrounding the target point, with exception of a forward cone of 5{sup 0} opening, are placed inside the lqHe-cryostat. The main features of the design and technique are as follows: a copper stabilizer and soldering technique for the superconducting cable; a stainless steel cryostat; winding technique over a mandrel; coreless type of the coil; low operational current. The details of the PANDA solenoid design including the magnetic field and stress-strain calculations are covered.

  15. Structure design of the central solenoid in JT-60SA

    International Nuclear Information System (INIS)

    Asakawa, Shuji; Tsuchiya, Katsuhiko; Kuramochi, Masaya; Yoshida, Kiyoshi

    2009-09-01

    The upgrade of JT-60U magnet system to superconducting coils (JT-60SA: JT-60 Super Advanced) has been decided by parties of Japanese government (JA) and European commission (EU) in the framework of the Broader Approach (BA) agreement. The magnet system for JT-60SA consists of a central solenoid (CS), equilibrium field(EF) coils, toroidal field(TF) coils. The central solenoid consists the four winding pack modules. In order to counteract the thermal contraction as well as the electric magnetic repulsion and attraction together with other forces generated in each module, it is necessary to apply pre-loading to the support structure of the solenoid and to pursue a structure which is capable of sustaining such loading. In the present report, the structural design of the supporting structure of the solenoid and the jackets of the modules is verified analytically, and the results indicate that the structural design satisfies the 'Codes for Fusion Facilities - Rules on Superconducting Magnet Structure -'. (author)

  16. Improved focus solenoid design for linear induction accelerators

    International Nuclear Information System (INIS)

    Zentler, J.M.; Van Maren, R.D.; Nexsen, W.E.

    1992-08-01

    Our FXR linear induction accelerator produces a 2 KA, 17 MeV electron beam of 60 ns duration. The beam is focused on a tantalum target to produce x-rays for radiography. The FWHM spot size of the focused beam is currently 2.2 mm. We strive to reduce the spot size by 30% by improving the field characteristics of focusing solenoids housed in each of 50 induction cells along the beamline. Tilts in the magnetic axis of the existing solenoids range up to 12 mrad (0.7 degrees). We are building new solenoid assemblies which include ferromagnetic homogenizer rings. These dramatically reduce field errors. A field tilt of under 0.5 mrad has been achieved. Mechanical alignment of the rings is critical. We developed a novel construction method in which the rings are wound with 4 mil thick Si-Fe ribbon into grooves on an aluminum cylinder. The cylinder then becomes the winding mandrel for the focus solenoids. This forms a more accurate and compact assembly than the standard practice of pressing individual solid rings onto a tube

  17. Modeling plasma flow in straight and curved solenoids

    International Nuclear Information System (INIS)

    Boercker, D.B.; Sanders, D.M.; Storer, J.; Falabella, S.

    1991-01-01

    The ''flux-tube'' model originated by Morozov is a very simple and numerically efficient method for simulating ion motion in plasma filters. In order to test its utility as a design tool, we compare the predictions of the model to recent experimental measurements of plasma flow in both straight and curved solenoids

  18. Completion of the ITER central solenoid model coils installation

    International Nuclear Information System (INIS)

    Tsuji, H.

    1999-01-01

    The short article details how dozens of problems, regarding the central solenoid model coils installation, were faced and successfully overcome one by one at JAERI-Naga. A black and white photograph shows K. Kwano, a staff member of the JAERI superconducting magnet laboratory, to be still inside the vacuum tank while the lid is already being brought down..

  19. Low-energy nuclear reactions with double-solenoid

    Indian Academy of Sciences (India)

    The University of Notre Dame, USA (Becchetti et al, Nucl. Instrum. Methods Res. A505, 377 (2003)) and later the University of São Paulo, Brazil (Lichtenthaler et al, Eur. Phys. J. A25, S-01, 733 (2005)) adopted a system based on superconducting solenoids to produce low-energy radioactive nuclear beams. In these systems ...

  20. Insulating process for HT-7U central solenoid model coils

    International Nuclear Information System (INIS)

    Cui Yimin; Pan Wanjiang; Wu Songtao; Wan Yuanxi

    2003-01-01

    The HT-7U superconducting Tokamak is a whole superconducting magnetically confined fusion device. The insulating system of its central solenoid coils is critical to its properties. In this paper the forming of the insulating system and the vacuum-pressure-impregnating (VPI) are introduced, and the whole insulating process is verified under the super-conducting experiment condition

  1. Electromagnetic behaviour of the shield in turbogenerators with superconducting solenoids

    International Nuclear Information System (INIS)

    Del Vecchio, P.; Veca, G.M.; Sacerdoti, G.

    1975-11-01

    The structure of turbogenerators with superconducting solenoids is analyzed and the investigation of electromagnetic behaviour of the rotating shield is presented. The cases considered are: (a) An hypothetical operation with a single phase with nominal current; (b) Steady-state operation in inverse sequence with 10% of the nominal current; (c) A step variation of the magnetic field intensity in the shield

  2. Design of 9 tesla superconducting solenoid for VECC RIB facility

    International Nuclear Information System (INIS)

    Das, Chiranjib; Ghosh, Siddhartha; Fatma, Tabassum; Dey, Malay Kanti; Bhunia, Uttam; Bandyopadhyay, Arup; Chakrabarti, Alok

    2013-01-01

    An ISOL post-accelerator type of RIB facility is being developed at our centre. The post acceleration scheme of a Radio Frequency Quadrupole (RFQ) followed by five IH LINAC cavities will provide energy of about 1.05 MeV/u. For further accelerating up to 2 MeV/u Superconducting Quarter Wave Resonators (SCQWR) will be used. The radial defocusing of the beam bunch during the acceleration using SCQWRs will be taken care of by a Superconducting Solenoid (SCS) within the same cryostat. In this report the electromagnetic design of an SCS will be discussed. A 9 T SCS having effective length of 340 mm has been designed with the special requirement that the fringing field should fall sharply to a value less than 100 mT at the surfaces of the adjacent superconducting cavities. The designed solenoid comprise of two co-axial split solenoid conductors surrounded by iron shields and a pair of bucking coils. Optimizations have been carried out for the total current sharing of the main coils and the bucking coils as well as for the relative orientation and dimension of each component of the solenoid. (author)

  3. Design of 9 tesla superconducting solenoid for VECC RIB facility

    Energy Technology Data Exchange (ETDEWEB)

    Das, Chiranjib; Ghosh, Siddhartha; Fatma, Tabassum; Dey, Malay Kanti; Bhunia, Uttam; Bandyopadhyay, Arup; Chakrabarti, Alok [Variable Energy Cyclotron Centre, Kolkata (India)

    2013-07-01

    An ISOL post-accelerator type of RIB facility is being developed at our centre. The post acceleration scheme of a Radio Frequency Quadrupole (RFQ) followed by five IH LINAC cavities will provide energy of about 1.05 MeV/u. For further accelerating up to 2 MeV/u Superconducting Quarter Wave Resonators (SCQWR) will be used. The radial defocusing of the beam bunch during the acceleration using SCQWRs will be taken care of by a Superconducting Solenoid (SCS) within the same cryostat. In this report the electromagnetic design of an SCS will be discussed. A 9 T SCS having effective length of 340 mm has been designed with the special requirement that the fringing field should fall sharply to a value less than 100 mT at the surfaces of the adjacent superconducting cavities. The designed solenoid comprise of two co-axial split solenoid conductors surrounded by iron shields and a pair of bucking coils. Optimizations have been carried out for the total current sharing of the main coils and the bucking coils as well as for the relative orientation and dimension of each component of the solenoid. (author)

  4. Fabrication, Testing and Modeling of the MICE Superconducting Spectrometer Solenoids

    International Nuclear Information System (INIS)

    Virostek, S.P.; Green, M.A.; Trillaud, F.; Zisman, M.S.

    2010-01-01

    The Muon Ionization Cooling Experiment (MICE), an international collaboration sited at Rutherford Appleton Laboratory in the UK, will demonstrate ionization cooling in a section of realistic cooling channel using a muon beam. A five-coil superconducting spectrometer solenoid magnet will provide a 4 tesla uniform field region at each end of the cooling channel. Scintillating fiber trackers within the 400 mm diameter magnet bore tubes measure the emittance of the beam as it enters and exits the cooling channel. Each of the identical 3-meter long magnets incorporates a three-coil spectrometer magnet section and a two-coil section to match the solenoid uniform field into the other magnets of the MICE cooling channel. The cold mass, radiation shield and leads are currently kept cold by means of three two-stage cryocoolers and one single-stage cryocooler. Liquid helium within the cold mass is maintained by means of a re-condensation technique. After incorporating several design changes to improve the magnet cooling and reliability, the fabrication and acceptance testing of the spectrometer solenoids have proceeded. The key features of the spectrometer solenoid magnets, the development of a thermal model, the results of the recently completed tests, and the current status of the project are presented.

  5. Design, fabrication, and characterization of a solenoid system to ...

    Indian Academy of Sciences (India)

    system to generate magnetic field for an ECR proton source. S K JAIN .... The bore of the solenoid coils was fabricated using high voltage glass epoxy. Each ... sure drop and flow, the inlet and outlet connections were provided. ... stability of an ECR plasma source, as any small change in the distribution of the axial magnetic.

  6. Three dimensional multilayer solenoid microcoils inside silica glass

    Science.gov (United States)

    Meng, Xiangwei; Yang, Qing; Chen, Feng; Shan, Chao; Liu, Keyin; Li, Yanyang; Bian, Hao; Si, Jinhai; Hou, Xun

    2016-01-01

    Three dimensional (3D) solenoid microcoils could generate uniform magnetic field. Multilayer solenoid microcoils are highly pursued for strong magnetic field and high inductance in advanced magnetic microsystems. However, the fabrication of the 3D multilayer solenoid microcoils is still a challenging task. In this paper, 3D multilayer solenoid microcoils with uniform diameters and high aspect ratio were fabricated in silica glass. An alloy (Bi/In/Sn/Pb) with high melting point was chosen as the conductive metal to overcome the limitation of working temperature and improve the electrical property. The inductance of the three layers microcoils was measured, and the value is 77.71 nH at 100 kHz and 17.39 nH at 120 MHz. The quality factor was calculated, and it has a value of 5.02 at 120 MHz. This approach shows an improvement method to achieve complex 3D metal microstructures and electronic components, which could be widely integrated in advanced magnetic microsystems.

  7. Design of a Solenoid Magnet for a Microwave Ion Source

    International Nuclear Information System (INIS)

    Cho, Yong Sub; Kwon, Hyeok Jung; Kim, Dae Il

    2011-01-01

    A microwave ion source has many advantages, such as long-life time, low emittance, high brightness, and compactness. Also it is a big merit that 2.45GHz rf systems are easily available and inexpensive. Due to the reasons microwave ion sources are very attractive for industrial applications. But microwave ion sources need a solenoid magnet which is usually an electromagnet with a DC current power supply. The electromagnet solenoids of microwave ion sources can be installed in two methods. The first method is to use isolation transformer to supply electrical power to DC current power supply for the magnets. In this case the magnet is compact because it has the same potential with the extraction voltage. The second method is to put an electrical insulator, such as G10, between ion sources and magnets. In this case the solenoid magnet is bigger than one in the first method, especially for higher extraction voltage, because the space for the insulator is required. Permanent magnets can be a good candidate to make microwave ion source more compact. But it is difficult to control the magnetic field profile and the magnetic flux density for the permanent magnet solenoids. Due to the reason, in the case that the best performances in many operating conditions should be achieved by adjusting the profile and strength of the solenoid, electromagnet is better than permanent magnet. But in the case of industrial applications where operating conditions is usually fixed and the compactness is required, permanent magnet is better choice to build an ion source

  8. Pattern formation in the bistable Gray-Scott model

    DEFF Research Database (Denmark)

    Mazin, W.; Rasmussen, K.E.; Mosekilde, Erik

    1996-01-01

    The paper presents a computer simulation study of a variety of far-from-equilibrium phenomena that can arise in a bistable chemical reaction-diffusion system which also displays Turing and Hopf instabilities. The Turing bifurcation curve and the wave number for the patterns of maximum linear grow...

  9. Dynamics of a bistable Miura-origami structure

    Science.gov (United States)

    Fang, Hongbin; Li, Suyi; Ji, Huimin; Wang, K. W.

    2017-05-01

    Origami-inspired structures and materials have shown extraordinary properties and performances originating from the intricate geometries of folding. However, current state of the art studies have mostly focused on static and quasistatic characteristics. This research performs a comprehensive experimental and analytical study on the dynamics of origami folding through investigating a stacked Miura-Ori (SMO) structure with intrinsic bistability. We fabricate and experimentally investigated a bistable SMO prototype with rigid facets and flexible crease lines. Under harmonic base excitation, the SMO exhibits both intrawell and interwell oscillations. Spectrum analyses reveal that the dominant nonlinearities of SMO are quadratic and cubic, which generate rich dynamics including subharmonic and chaotic oscillations. The identified nonlinearities indicate that a third-order polynomial can be employed to approximate the measured force-displacement relationship. Such an approximation is validated via numerical study by qualitatively reproducing the phenomena observed in the experiments. The dynamic characteristics of the bistable SMO resemble those of a Helmholtz-Duffing oscillator (HDO); this suggests the possibility of applying the established tools and insights of HDO to predict origami dynamics. We also show that the bistability of SMO can be programmed within a large design space via tailoring the crease stiffness and initial stress-free configurations. The results of this research offer a wealth of fundamental insights into the dynamics of origami folding, and provide a solid foundation for developing foldable and deployable structures and materials with embedded dynamic functionalities.

  10. Dynamics of a bistable Miura-origami structure.

    Science.gov (United States)

    Fang, Hongbin; Li, Suyi; Ji, Huimin; Wang, K W

    2017-05-01

    Origami-inspired structures and materials have shown extraordinary properties and performances originating from the intricate geometries of folding. However, current state of the art studies have mostly focused on static and quasistatic characteristics. This research performs a comprehensive experimental and analytical study on the dynamics of origami folding through investigating a stacked Miura-Ori (SMO) structure with intrinsic bistability. We fabricate and experimentally investigated a bistable SMO prototype with rigid facets and flexible crease lines. Under harmonic base excitation, the SMO exhibits both intrawell and interwell oscillations. Spectrum analyses reveal that the dominant nonlinearities of SMO are quadratic and cubic, which generate rich dynamics including subharmonic and chaotic oscillations. The identified nonlinearities indicate that a third-order polynomial can be employed to approximate the measured force-displacement relationship. Such an approximation is validated via numerical study by qualitatively reproducing the phenomena observed in the experiments. The dynamic characteristics of the bistable SMO resemble those of a Helmholtz-Duffing oscillator (HDO); this suggests the possibility of applying the established tools and insights of HDO to predict origami dynamics. We also show that the bistability of SMO can be programmed within a large design space via tailoring the crease stiffness and initial stress-free configurations. The results of this research offer a wealth of fundamental insights into the dynamics of origami folding, and provide a solid foundation for developing foldable and deployable structures and materials with embedded dynamic functionalities.

  11. Reversal Negativity and Bistable Stimuli: Attention, Awareness, or Something Else?

    Science.gov (United States)

    Intaite, Monika; Koivisto, Mika; Ruksenas, Osvaldas; Revonsuo, Antti

    2010-01-01

    Ambiguous (or bistable) figures are visual stimuli that have two mutually exclusive perceptual interpretations that spontaneously alternate with each other. Perceptual reversals, as compared with non-reversals, typically elicit a negative difference called reversal negativity (RN), peaking around 250 ms from stimulus onset. The cognitive…

  12. Kerr nonlinearity and plasmonic bistability in graphene nanoribbons

    DEFF Research Database (Denmark)

    Christensen, Thomas; Yan, Wei; Jauho, Antti-Pekka

    2015-01-01

    due to field enhancement, and the total nonlinearity is significantly affected by the field inhomogeneity of the plasmonic excitation. Finally, we discuss the emergence of a plasmonic bistability which exists for energies red-shifted relative to the linear resonance. Our results offer insights...

  13. Drag force actuated bistable microswitches for flow sensing

    NARCIS (Netherlands)

    Kuipers, W.J.; van Baar, J.J.J.; Dijkstra, Marcel; Wiegerink, Remco J.; Lammerink, Theodorus S.J.; de Boer, J.H.; Krijnen, Gijsbertus J.M.

    2006-01-01

    This paper presents bistable microswitches with Au contacts with the aim to combine them with artificial hairs for flow sensing. The Au contacts are applied on both ends of a silicon nitride beam, suspended by a torsional bar at its center. The beam is provided with electrodes for electrostatic

  14. Bistable minimum energy structures (BiMES) for binary robotics

    International Nuclear Information System (INIS)

    Follador, M; Conn, A T; Rossiter, J

    2015-01-01

    Bistable minimum energy structures (BiMES) are devices derived from the union of the concepts of dielectric elastomer minimum energy structures and bistable systems. This article presents this novel approach to active, elastic and bistable structures. BiMES are based on dielectric elastomer actuators (DEAs), which act as antagonists and provide the actuation for switching between the two equilibrium positions. A central elastic beam is the backbone of the structure and is buckled into the minimum energy configurations by the action of the two DEAs. The theory and the model of the device are presented, and also its fabrication process. BiMES are considered as fundamental units for more complex structures, which are presented and fabricated as proof of concept. Two different ways of combining the multiple units are proposed: a parallel configuration, to make a simple gripper, and a serial configuration, to generate a binary device. The possibility of using the bistable system as a continuous bender actuator, by modulating the actuation voltage of the two DEAs, was also investigated. (paper)

  15. Phenomenological approach to bistable behavior of Josephson junctions

    International Nuclear Information System (INIS)

    Nishi, K.; Nara, S.; Hamanaka, K.

    1985-01-01

    The interaction of unbiased Josephson junction with external electromagnetic field in the presence of externally applied uniform magnetic field is theoretically examined by means of phenomenological treatment. It is proposed that an irradiated junction with suitably chosen parameters shows a bistable behavior of voltage across the junction as a function of the radiation intensity

  16. The Compact Muon Solenoid Experiment at the Large Hadron Collider The Compact Muon Solenoid Experiment at the Large Hadron Collider

    Directory of Open Access Journals (Sweden)

    David Delepine

    2012-02-01

    Full Text Available The Compact Muon Solenoid experiment at the CERN Large Hadron Collider will study protonproton collisions at unprecedented energies and luminosities. In this article we providefi rst a brief general introduction to particle physics. We then explain what CERN is. Thenwe describe the Large Hadron Collider at CERN, the most powerful particle acceleratorever built. Finally we describe the Compact Muon Solenoid experiment, its physics goals,construction details, and current status.El experimento Compact Muon Solenoid en el Large Hadron Collider del CERN estudiarácolisiones protón protón a energías y luminosidades sin precedente. En este artículo presentamos primero una breve introducción general a la física de partículas. Despuésexplicamos lo que es el CERN. Luego describimos el Large Hadron Collider, el más potente acelerador de partículas construido por el hombre, en el CERN. Finalmente describimos el experimento Compact Muon Solenoid, sus objetivos en física, los detalles de su construcción,y su situación presente.

  17. Transition of some type of integrated circuits into latch-up mode under effect of ionizing radiation of large dose rate

    International Nuclear Information System (INIS)

    Berdichevskij, B.E.; Madzharova, T.B.

    1986-01-01

    Some types of integrated circuits (IC) are almost short-circuit, i.e. they transit to the latch-up regime under the effect of ionizing radiation pulses of large dose rate. The results of investigation into IC under their transition into the latch-up regime at supply voltage of 10 V are presented. It is shown that IC stably transit to the latch-up regime if the dinistor current becomes at least equal to the photocurrent. At bias reduction from 15 to 6 V the dose rate at which the latch-up arises grows from 2.5x10 9 to 3.5x10 9 rad (Si)/s. Burn-out of supply busbar is the usual type of IC failure at latch-up arising. Measures for IC protection from latch-up are shown. In some IC the latch-up is formed beginning from a certain critical value of dose rate, the so-called ''windows'' of latch-up

  18. The large superconducting solenoids for the g-2 muon storage ring

    International Nuclear Information System (INIS)

    Bunce, G.; Cullen, J.; Danby, G.

    1994-01-01

    The g-2 muon storage ring at Brookhaven National Laboratory consists of four large superconducting solenoids. The two outer solenoids, which are 15.1 meters in diameter, share a common cryostat. The two inner solenoids, which are 13.4 meters in diameter, are in separate cryostats. The two 24 turn inner solenoids are operated at an opposite polarity from the two 24 turn outer solenoids. This generates a dipole field between the inner and outer solenoids. The flux between the solenoids is returned through a C shaped iron return yoke that also shapes the dipole field. The integrated field around the 14 meter diameter storage ring must be good to about 1 part in one million over the 90 mm dia. circular cross section where the muons are stored, averaged over the azimuth. When the four solenoids carry their 5300 A design current, the field in the 18 centimeter gap between the poles is 1.45 T. When the solenoid operates at its design current 5.5 MJ is stored between the poles. The solenoids were wound on site at Brookhaven National Laboratory. The cryostats were built around the solenoid windings which are indirectly cooled using two-phase helium

  19. IE Information Notice No. 85-17, Supplement 1: Possible sticking of ASCO solenoid valves

    International Nuclear Information System (INIS)

    Jordan, E.L.

    1992-01-01

    This notice is to inform recipients of the results of follow up investigations regarding the reasons for sticking of Automatic Switch Company (ASCO) solenoid valves used to shut main steam isolation valves (MSIVs) under accident conditions. GE has recommend that the licensee replace the potentially contaminated MSIV solenoid valves and institute a periodic examination and cleaning of the MSIV solenoid valves. Grand Gulf has replaced the eight MSIV HTX832320V dual solenoid valves with fully environmentally qualified ASCO Model NP 8323A20E dual solenoid valves. The environmentally qualified valve Model NP 8323A20E was included in a control sample placed in the test ovens with the solenoid valves that stuck at Grand Gulf. The environmentally qualified model did not stick under the test conditions that cause sticking in the other solenoid valves

  20. Focusing solenoid for the front end of a linear RF accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Terechkine, I.; Kashikhin, V.V.; Page, T.; Tartaglia, M.; Tompkins, J.; /Fermilab

    2007-06-01

    A prototype of a superconducting focusing solenoid for use in an RF linac has been built and tested at Fermi National Accelerator Laboratory (FNAL). The solenoid is comprised of the main coil, two bucking coils, two dipole corrector windings, and a low carbon steel flux return. At the excitation current of 250 A, the magnetic field reaches 7.2 T in the center of the solenoid and is less than 5 G on the axis at a distance of 150 mm from the center. The length of the solenoid is 150 mm; the length of a cryovessel for the solenoid with a 20 mm diameter 'warm' bore is 270 mm. This paper presents the main design features of the focusing solenoid and discusses results from tests of the solenoid.

  1. Bistable dynamics of a levitated nanoparticle (Presentation Recording)

    Science.gov (United States)

    Ricci, Francesco; Spasenovic, M.; Rica, Raúl A.; Novotny, Lukas; Quidant, Romain

    2015-08-01

    Bistable systems are ubiquitous in nature. Classical examples in chemistry and biology include relaxation kinetics in chemical reactions [1] and stochastic resonance processes such as neuron firing [2,3]. Likewise, bistable systems play a key role in signal processing and information handling at the nanoscale, giving rise to intriguing applications such as optical switches [4], coherent signal amplification [5,6] and weak forces detection [5]. The interest and applicability of bistable systems are intimately connected with the complexity of their dynamics, typically due to the presence of a large number of parameters and nonlinearities. Appropriate modeling is therefore challenging. Alternatively, the possibility to experimentally recreate bistable systems in a clean and controlled way has recently become very appealing, but elusive and complicated. With this aim, we combined optical tweezers with a novel active feedback-cooling scheme to develop a well-defined opto-mechanical platform reaching unprecedented performances in terms of Q-factor, frequency stability and force sensitivity [7,8]. Our experimental system consists of a single nanoparticle levitated in high vacuum with optical tweezers, which behaves as a non-linear (Duffing) oscillator under appropriate conditions. Here, we prove it to be an ideal tool for a deep study of bistability. We demonstrate bistability of the nanoparticle by noise activated switching between two oscillation states, discussing our results in terms of a double-well potential model. We also show the flexibility of our system in shaping the potential at will, in order to meet the conditions prescribed by any bistable system that could therefore then be simulated with our setup. References [1] T. Amemiya, T. Ohmori, M. Nakaiwa, T. Yamamoto, and T. Yamaguchi, "Modeling of Nonlinear Chemical Reaction Systems and Two-Parameter Stochastic Resonance," J. Biol. Phys. 25 (1999) 73 [2] F. Moss, L. M. Ward, and W. G. Sannita, "Stochastic

  2. Completeness for coherent states in a magnetic–solenoid field

    International Nuclear Information System (INIS)

    Bagrov, V G; Gavrilov, S P; Gitman, D M; Górska, K

    2012-01-01

    This paper completes our study of coherent states in the so-called magnetic–solenoid field (a collinear combination of a constant uniform magnetic field and Aharonov–Bohm solenoid field) presented in Bagrov et al (2010 J. Phys. A: Math. Theor. 43 354016, 2011 J. Phys. A: Math. Theor. 44 055301). Here, we succeeded in proving nontrivial completeness relations for non-relativistic and relativistic coherent states in such a field. In addition, we solve here the relevant Stieltjes moment problem and present a comparative analysis of our coherent states and the well-known, in the case of pure uniform magnetic field, Malkin–Man’ko coherent states. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Coherent states: mathematical and physical aspects’. (paper)

  3. Conceptual design of the CMS 4 Tesla solenoid

    International Nuclear Information System (INIS)

    Baze, J.M.; Desportes, H.; Duthil, R.; Lesmond, C.; Lottin, J.C.; Pabot, Y.

    1992-02-01

    A large and important meeting 'Toward the LHC experimental programme' is due to be held at EVIAN-les-BAINS, on 5-8 March 1992. The major goal accurate measurement of muon momenta makes necessary, for the detectors, the use of large and powerful magnetic system producing high bending power. The CMS experiment is based on a solenoidal magnetic configuration. It has been designed to produce a high magnetic induction (4 T) in a 14 m long, 5.9 m bore cylindrical volume surrounding the interaction point. The diameter has been fixed to the maximum dimension compatible with road transportation to CERN. This long solenoid with its 12 500 ton iron yoke is a fully shielded magnet. The paper presents the conceptual design of the superconducting coil and its technical characteristics

  4. H- beam neutralization measurements in a solenoidal beam transport system

    International Nuclear Information System (INIS)

    Sherman, J.; Pitcher, E.; Stevens, R.; Allison, P.

    1992-01-01

    H minus beam space-charge neutralization is measured for 65-mA, 35-keV beams extracted from a circular-aperture Penning surface-plasma source, the small-angle source. The H minus beam is transported to a RFQ matchpoint by a two-solenoid magnet system. Beam noise is typically ±4%. A four-grid analyzer is located in a magnetic-field-free region between the two solenoid magnets. H minus potentials are deduced from kinetic energy measurements of particles (electrons and positive ions) ejected radially from the beam channel by using a griddled energy analyzer. Background neutral gas density is increased by the introduction of additional Xe and Ar gases, enabling the H minus beam to become overneutralized

  5. Plasma shape control by pulsed solenoid on laser ion source

    International Nuclear Information System (INIS)

    Sekine, M.; Ikeda, S.; Romanelli, M.; Kumaki, M.; Fuwa, Y.; Kanesue, T.; Hayashizaki, N.; Lambiase, R.; Okamura, M.

    2015-01-01

    A Laser ion source (LIS) provides high current heavy ion beams with a very simple mechanical structure. Plasma is produced by a pulsed laser ablation of a solid state target and ions are extracted by an electric field. However, it was difficult to manipulate the beam parameters of a LIS, since the plasma condition could only be adjusted by the laser irradiation condition. To enhance flexibility of LIS operation, we employed a pulsed solenoid in the plasma drift section and investigated the effect of the solenoid field on singly charged iron beams. The experimentally obtained current profile was satisfactorily controlled by the pulsed magnetic field. This approach may also be useful to reduce beam emittance of a LIS

  6. Design of High Field Solenoids made of High Temperature Superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Bartalesi, Antonio; /Pisa U.

    2010-12-01

    This thesis starts from the analytical mechanical analysis of a superconducting solenoid, loaded by self generated Lorentz forces. Also, a finite element model is proposed and verified with the analytical results. To study the anisotropic behavior of a coil made by layers of superconductor and insulation, a finite element meso-mechanic model is proposed and designed. The resulting material properties are then used in the main solenoid analysis. In parallel, design work is performed as well: an existing Insert Test Facility (ITF) is adapted and structurally verified to support a coil made of YBa{sub 2}Cu{sub 3}O{sub 7}, a High Temperature Superconductor (HTS). Finally, a technological winding process was proposed and the required tooling is designed.

  7. Effect of solenoidal magnetic field on drifting laser plasma

    Science.gov (United States)

    Takahashi, Kazumasa; Okamura, Masahiro; Sekine, Megumi; Cushing, Eric; Jandovitz, Peter

    2013-04-01

    An ion source for accelerators requires to provide a stable waveform with a certain pulse length appropriate to the application. The pulse length of laser ion source is easy to control because it is expected to be proportional to plasma drifting distance. However, current density decay is proportional to the cube of the drifting distance, so large current loss will occur under unconfined drift. We investigated the stability and current decay of a Nd:YAG laser generated copper plasma confined by a solenoidal field using a Faraday cup to measure the current waveform. It was found that the plasma was unstable at certain magnetic field strengths, so a baffle was introduced to limit the plasma diameter at injection and improve the stability. Magnetic field, solenoid length, and plasma diameter were varied in order to find the conditions that minimize current decay and maximize stability.

  8. Plasma shape control by pulsed solenoid on laser ion source

    Science.gov (United States)

    Sekine, M.; Ikeda, S.; Romanelli, M.; Kumaki, M.; Fuwa, Y.; Kanesue, T.; Hayashizaki, N.; Lambiase, R.; Okamura, M.

    2015-09-01

    A Laser ion source (LIS) provides high current heavy ion beams with a very simple mechanical structure. Plasma is produced by a pulsed laser ablation of a solid state target and ions are extracted by an electric field. However, it was difficult to manipulate the beam parameters of a LIS, since the plasma condition could only be adjusted by the laser irradiation condition. To enhance flexibility of LIS operation, we employed a pulsed solenoid in the plasma drift section and investigated the effect of the solenoid field on singly charged iron beams. The experimentally obtained current profile was satisfactorily controlled by the pulsed magnetic field. This approach may also be useful to reduce beam emittance of a LIS.

  9. Transverse emittance measurement at REGAE via a solenoid scan

    Energy Technology Data Exchange (ETDEWEB)

    Hachmann, Max

    2012-12-15

    The linear accelerator REGAE at DESY produces short and low charged electron bunches, on the one hand to resolve the excitation transitions of atoms temporally by pump probe electron diffraction experiments and on the other hand to investigate principal mechanisms of laser plasma acceleration. For both cases a high quality electron beam is required. A quantity to rate the beam quality is the beam emittance. In the course of this thesis transverse emittance measurements by a solenoid scan could be realized and beyond that an improved theoretical description of a solenoid was successful. The foundation of emittance measurements are constituted by theoretical models which describe the envelope of a beam. Two different models were derived. The first is an often used model to determine the transverse beam emittance without considering space charge effects. More interesting and challenging was the development of an envelope model taking space charge effects into account. It is introduced and cross checked with measurements and simulations.

  10. Effect of solenoidal magnetic field on drifting laser plasma

    International Nuclear Information System (INIS)

    Takahashi, Kazumasa; Sekine, Megumi; Okamura, Masahiro; Cushing, Eric; Jandovitz, Peter

    2013-01-01

    An ion source for accelerators requires to provide a stable waveform with a certain pulse length appropriate to the application. The pulse length of laser ion source is easy to control because it is expected to be proportional to plasma drifting distance. However, current density decay is proportional to the cube of the drifting distance, so large current loss will occur under unconfined drift. We investigated the stability and current decay of a Nd:YAG laser generated copper plasma confined by a solenoidal field using a Faraday cup to measure the current waveform. It was found that the plasma was unstable at certain magnetic field strengths, so a baffle was introduced to limit the plasma diameter at injection and improve the stability. Magnetic field, solenoid length, and plasma diameter were varied in order to find the conditions that minimize current decay and maximize stability.

  11. Effect of solenoidal magnetic field on drifting laser plasma

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Kazumasa; Sekine, Megumi [Tokyo Institute of Technology, Yokohama 226-8502 (Japan); Okamura, Masahiro [Brookhaven National Laboratory, Upton, NY 11973 (United States) and RIKEN, Wako-shi, Saitama 351-0198 (United States); Cushing, Eric [Pennsylvania State University, University Park, PA 16802 (United States); Jandovitz, Peter [Cornell University, Ithaca, NY 14853 (United States)

    2013-04-19

    An ion source for accelerators requires to provide a stable waveform with a certain pulse length appropriate to the application. The pulse length of laser ion source is easy to control because it is expected to be proportional to plasma drifting distance. However, current density decay is proportional to the cube of the drifting distance, so large current loss will occur under unconfined drift. We investigated the stability and current decay of a Nd:YAG laser generated copper plasma confined by a solenoidal field using a Faraday cup to measure the current waveform. It was found that the plasma was unstable at certain magnetic field strengths, so a baffle was introduced to limit the plasma diameter at injection and improve the stability. Magnetic field, solenoid length, and plasma diameter were varied in order to find the conditions that minimize current decay and maximize stability.

  12. Plasma shape control by pulsed solenoid on laser ion source

    Energy Technology Data Exchange (ETDEWEB)

    Sekine, M. [Tokyo Institute of Technology, Meguro-ku, Tokyo 2-12-1 (Japan); RIKEN, Wako, Saitama 351-0198 (Japan); Ikeda, S. [Tokyo Institute of Technology, Yokohama, Kanagawa 226-8502 (Japan); RIKEN, Wako, Saitama 351-0198 (Japan); Romanelli, M. [Cornell University, Ithaca, NY 14850 (United States); Kumaki, M. [RIKEN, Wako, Saitama 351-0198 (Japan); Waseda University, Shinjuku, Tokyo 169-0072 (Japan); Fuwa, Y. [RIKEN, Wako, Saitama 351-0198 (Japan); Kyoto University, Uji, Kyoto 611-0011 (Japan); Kanesue, T. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Hayashizaki, N. [Tokyo Institute of Technology, Meguro-ku, Tokyo 2-12-1 (Japan); Lambiase, R. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Okamura, M. [RIKEN, Wako, Saitama 351-0198 (Japan); Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2015-09-21

    A Laser ion source (LIS) provides high current heavy ion beams with a very simple mechanical structure. Plasma is produced by a pulsed laser ablation of a solid state target and ions are extracted by an electric field. However, it was difficult to manipulate the beam parameters of a LIS, since the plasma condition could only be adjusted by the laser irradiation condition. To enhance flexibility of LIS operation, we employed a pulsed solenoid in the plasma drift section and investigated the effect of the solenoid field on singly charged iron beams. The experimentally obtained current profile was satisfactorily controlled by the pulsed magnetic field. This approach may also be useful to reduce beam emittance of a LIS.

  13. Magnetic Alignment of Pulsed Solenoids Using the Pulsed Wire Method

    International Nuclear Information System (INIS)

    Arbelaez, D.; Madur, A.; Lipton, T.M.; Waldron, W.L.; Kwan, J.W.

    2011-01-01

    A unique application of the pulsed-wire measurement method has been implemented for alignment of 2.5 T pulsed solenoid magnets. The magnetic axis measurement has been shown to have a resolution of better than 25 (micro)m. The accuracy of the technique allows for the identification of inherent field errors due to, for example, the winding layer transitions and the current leads. The alignment system is developed for the induction accelerator NDCX-II under construction at LBNL, an upgraded Neutralized Drift Compression experiment for research on warm dense matter and heavy ion fusion. Precise alignment is essential for NDCX-II, since the ion beam has a large energy spread associated with the rapid pulse compression such that misalignments lead to corkscrew deformation of the beam and reduced intensity at focus. The ability to align the magnetic axis of the pulsed solenoids to within 100 pm of the induction cell axis has been demonstrated.

  14. Worchester Solenoid Actuated Gas Operated MCO Isolation Valves

    International Nuclear Information System (INIS)

    VAN KATWIJK, C.

    2000-01-01

    These valves are 1 inch gas-operated full-port ball valves incorporating a solenoid and limit switches as integral parts of the actuator that are used in process streams within the CVDF hood. The valves fail closed (on loss of pressure or electrical) to prevent MCO vent drain to either reduce air in-leakage or loss of He. The valves have couplings for transverse actuator mounting

  15. System of cylindrical drift chambers in a superconducting solenoid

    International Nuclear Information System (INIS)

    Camilleri, L.; Blumenfeld, B.J.; Dimcovski, Z.

    1978-01-01

    A superconducting solenoid at the CERN ISR was equipped with a system of high accuracy cylindrical drift chambers. This detector consists of eight layers of field shaped drift cells with a delay line opposite each sense wire to provide coupled two dimensional readout. The design, construction, and operation of this system are discussed. The resolution and performance of the delay lines and sense wires under ISR running conditions are shown

  16. HIE-ISOLDE CRYO-MODULE Assembly - Superconducting Solenoid

    CERN Multimedia

    Leclercq, Yann

    2016-01-01

    Assembly of the cryo-module components in SM18 cleanroom. The superconducting solenoid (housed inside its helium vessel) is cleaned, prepared then installed on the supporting frame of the cryo-module and connected to the helium tank, prior to the assembly of the RF cavities on the structure. The completed first 2 cryo-modules installed inside the HIE-ISOLDE-LINAC ready for beam operation is also shown.

  17. Synchrotron oscillation effects on an rf-solenoid spin resonance

    Science.gov (United States)

    Benati, P.; Chiladze, D.; Dietrich, J.; Gaisser, M.; Gebel, R.; Guidoboni, G.; Hejny, V.; Kacharava, A.; Kamerdzhiev, V.; Kulessa, P.; Lehrach, A.; Lenisa, P.; Lorentz, B.; Maier, R.; Mchedlishvili, D.; Morse, W. M.; Öllers, D.; Pesce, A.; Polyanskiy, A.; Prasuhn, D.; Rathmann, F.; Semertzidis, Y. K.; Stephenson, E. J.; Stockhorst, H.; Ströher, H.; Talman, R.; Valdau, Yu.; Weidemann, Ch.; Wüstner, P.

    2012-12-01

    New measurements are reported for the time dependence of the vertical polarization of a 0.97GeV/c deuteron beam circulating in a storage ring and perturbed by an rf solenoid. The storage ring is the cooler synchrotron (COSY) located at the Forschungszentrum Jülich. The beam polarization was measured continuously using a 1.5 cm thick carbon target located at the edge of the circulating deuteron beam and the scintillators of the EDDA detector. An rf solenoid mounted on the ring was used to generate fields at and near the frequency of the 1-Gγ spin resonance. Measurements were made of the vertical beam polarization as a function of time with the operation of the rf solenoid in either fixed or continuously variable frequency mode. Using rf-solenoid strengths as large as 2.66×10-5revolutions/turn, slow oscillations (˜1Hz) were observed in the vertical beam polarization. When the circulating beam was continuously electron cooled, these oscillations completely reversed the polarization and showed no sign of diminishing in amplitude. But for the uncooled beam, the oscillation amplitude was damped to nearly zero within a few seconds. A simple spin-tracking model without the details of the COSY ring lattice was successful in reproducing these oscillations and demonstrating the sensitivity of the damping to the magnitude of the synchrotron motion of the beam particles. The model demonstrates that the characteristic features of measurements made in the presence of large synchrotron oscillations are distinct from the features of such measurements when made off resonance. These data were collected in preparation for a study of the spin coherence time, a beam property that needs to become long to enable a search for an electric dipole moment using a storage ring.

  18. Sprag solenoid brake. [development and operations of electrically controlled brake

    Science.gov (United States)

    Dane, D. H. (Inventor)

    1974-01-01

    The development and characteristics of an electrically operated brake are discussed. The action of the brake depends on energizing a solenoid which causes internally spaced sprockets to contact the inner surface of the housing. A spring forces the control member to move to the braking position when the electrical function is interrupted. A diagram of the device is provided and detailed operating principles are explained.

  19. Electron Beam Size Measurements in a Cooling Solenoid

    CERN Document Server

    Kroc, Thomas K; Burov, Alexey; Seletsky, Sergey; Shemyakin, Alexander V

    2005-01-01

    The Fermilab Electron Cooling Project requires a straight trajectory and constant beam size to provide effective cooling of the antiprotons in the Recycler. A measurement system was developed using movable appertures and steering bumps to measure the beam size in a 20 m long, nearly continuous, solenoid. This paper discusses the required beam parameters, the implimentation of the measurement system and results for our application.

  20. Worcester Solenoid-Actuated Gas Operated MCO Isolation Valves

    International Nuclear Information System (INIS)

    VAN KATWIJK, C.

    2000-01-01

    These valves are 1 inch gas-operated full-port ball valves incorporating a solenoid and limit switches as Integral parts of the actuator that are used in different process streams within the CVDF hood. The valves fail closed (on loss of pressure or electrical) for MCO isolation to either reduce air in leakage or loss of He. All valves have coupling for transverse actuator mounting

  1. Superconducting solenoids for an international muon cooling experiment

    International Nuclear Information System (INIS)

    Green, M.A.; Rey, J.M.

    2002-01-01

    The international muon ionization cooling experiment MICE will consist of two focusing cooling cells and a pair of uniform field solenoids used for particle identification and emittance measurements. The 2.75-meter long cooling cells have a pair of field flip coils and a coupling coil. The 0.52-meter diameter field flip coils surround an absorber that removes transverse and longitudinal momentum from the muons to be cooled. The beam in the absorber is at a minimum beta point so that scattering of the muons is minimized. The 1.7-meter diameter coupling coils are outside of conventional 201.25 MHz RF cavities that accelerate the muons putting longitudinal momentum into the muons without putting back the transverse momentum into the beam. A third set of flip coils helps the muon beam transition from and to the experimental solenoids. The 0.6-meter diameter experimental solenoids have a uniform field region (good to about 1 part in 1000) that is 1.3-meters long. The MICE experiment magnets must operate as a single unit so that the field profile will produce the maximum muon cooling

  2. Design and characterization of permanent magnetic solenoids for REGAE

    International Nuclear Information System (INIS)

    Hachmann, M.; Flöttmann, K.; Gehrke, T.; Mayet, F.

    2016-01-01

    REGAE is a small electron linear accelerator at DESY. In order to focus short and low charged electron bunches down to a few μm permanent magnetic solenoids were designed, assembled and field measurements were done. Due to a shortage of space close to the operation area an in-vacuum solution has been chosen. Furthermore a two-ring design made of wedges has been preferred in terms of beam dynamic issues. To keep the field quality of a piecewise built magnet still high a sorting algorithm for the wedge arrangement including a simple magnetic field model has been developed and used for the construction of the magnets. The magnetic field of these solenoids has been measured with high precision and compared to simulations. - Highlights: • presenting a two-ring radially magnetized permanent magnetic solenoid design. • development of a analytical field description and field quality factor. • development of a sorting algorithm for permanent magnetic pieces to form a magnet. • performing a high-precision field measurement of a high gradient field.

  3. Strain-based quench detection for a solenoid superconducting magnet

    International Nuclear Information System (INIS)

    Wang Xingzhe; Guan Mingzhi; Ma Lizhen

    2012-01-01

    In this paper, we present a non-electric quench detection method based on the strain gauge measurement of a superconducting solenoid magnet at cryogenic temperature under an intense magnetic field. Unlike the traditional voltage measurement of quench detection, the strain-based detection method utilizes low-temperature strain gauges, which evidently reduce electromagnetic noise and breakdown, to measure the magneto/thermo-mechanical behavior of the superconducting magnet during excitation. The magnet excitation, quench tests and trainings were performed on a prototype 5 T superconducting solenoid magnet. The transient strains and their abrupt changes were compared with the current, magnetic field and temperature signals collected during excitation and quench tests to indicate that the strain gauge measurements can detect the quench feature of the superconducting magnet. The proposed method is expected to be able to detect the quench of a superconducting coil independently or utilized together with other electrical methods. In addition, the axial quench propagation velocity of the solenoid is evaluated by the quench time lags among different localized strains. The propagation velocity is enhanced after repeated quench trainings. (paper)

  4. Controlling the optical bistability and multistability in a two-level pumped-probe system

    International Nuclear Information System (INIS)

    Mahmoudi, Mohammad; Sahrai, Mostafa; Masoumeh Mousavi, Seyede

    2010-01-01

    We study the behavior of the optical bistability (OB) and multistability (OM) in a two-level pumped-probe atomic system by means of a unidirectional ring cavity. We show that the optical bistability in a two-level atomic system can be controlled by adjusting the intensity of the pump field and the detuning between two fields. We find that applying the pumping field decreases the threshold of the optical bistability.

  5. Bistability and self-oscillations effects in a polariton-laser semiconductor microcavity

    International Nuclear Information System (INIS)

    Cotta, E A; Matinaga, F M

    2007-01-01

    We report an experimental observation of polaritonic optical bistability of the laser emission in a planar semiconductor microcavity with a 100 0 A GaAs single quantum well in the strong-coupling regime. The bistability curves show crossings that indicate a competition between a Kerr-like effect induced by the polariton population and thermal effects. Associated with the bistability, laser-like emission occurs at the bare cavity mode

  6. Understanding drivers of peatland extracellular enzyme activity in the PEATcosm experiment: mixed evidence for enzymic latch hypothesis

    Science.gov (United States)

    Karl J. Romanowicz; Evan S. Kane; Lynette R. Potvin; Aleta L. Daniels; Randy Kolka; Erik A. Lilleskov

    2015-01-01

    Aims. Our objective was to assess the impacts of water table position and plant functional groups on peatland extracellular enzyme activity (EEA) framed within the context of the enzymic latch hypothesis. Methods. We utilized a full factorial experiment with 2 water table (WT) treatments (high and low) and 3 plant functional...

  7. Modeling bistable behaviors in morphing structures through finite element simulations.

    Science.gov (United States)

    Guo, Qiaohang; Zheng, Huang; Chen, Wenzhe; Chen, Zi

    2014-01-01

    Bistable structures, exemplified by the Venus flytrap and slap bracelets, can transit between different configurations upon certain external stimulation. Here we study, through three-dimensional finite element simulations, the bistable behaviors in elastic plates in the absence of terminate loads, but with pre-strains in one (or both) of the two composite layers. Both the scenarios with and without a given geometric mis-orientation angle are investigated, the results of which are consistent with recent theoretical and experimental studies. This work can open ample venues for programmable designs of plant/shell structures with large deformations, with applications in designing bio-inspired robotics for biomedical research and morphing/deployable structures in aerospace engineering.

  8. Coupling-induced oscillations in nonhomogeneous, overdamped, bistable systems

    International Nuclear Information System (INIS)

    Hernandez, Mayra; In, Visarath; Longhini, Patrick; Palacios, Antonio; Bulsara, Adi; Kho, Andy

    2008-01-01

    Coupling-induced oscillations in a homogeneous network of overdamped bistable systems have been previously studied both theoretically and experimentally for a system of N (odd) elements, unidirectionally coupled in a ring topology. In this work, we extend the analysis of this system to include a network of nonhomogeneous elements with respect to the parameter that controls the topology of the potential function and the bistability of each element. In particular, we quantify the effects of the nonhomogeneity on the onset of oscillations and the response of the network to external (assumed to be constant and very small) perturbations, using our (recently developed) coupled core fluxgate magnetometer as a representative system. The potential applications of this work include signal detection and characterization for a large class of sensor systems

  9. Coupling-induced oscillations in nonhomogeneous, overdamped, bistable systems

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Mayra [Nonlinear Dynamical Systems Group, Department of Mathematics and Statistics, San Diego State University, San Diego, CA 92182 (United States)], E-mail: mayra.alina@yahoo.com; In, Visarath [Space and Naval Warfare Systems Center, Code 71730, 53560 Hull Street, San Diego, CA 92152-5001 (United States)], E-mail: visarath.in@navy.mil; Longhini, Patrick [Space and Naval Warfare Systems Center, Code 71730, 53560 Hull Street, San Diego, CA 92152-5001 (United States)], E-mail: longhini@navy.mil; Palacios, Antonio [Nonlinear Dynamical Systems Group, Department of Mathematics and Statistics, San Diego State University, San Diego, CA 92182 (United States)], E-mail: palacios@euler.sdsu.edu; Bulsara, Adi [Space and Naval Warfare Systems Center, Code 71730, 53560 Hull Street, San Diego, CA 92152-5001 (United States)], E-mail: bulsara@spawar.navy.mil; Kho, Andy [Space and Naval Warfare Systems Center, Code 71730, 53560 Hull Street, San Diego, CA 92152-5001 (United States)], E-mail: kho@spawar.navy.mil

    2008-06-09

    Coupling-induced oscillations in a homogeneous network of overdamped bistable systems have been previously studied both theoretically and experimentally for a system of N (odd) elements, unidirectionally coupled in a ring topology. In this work, we extend the analysis of this system to include a network of nonhomogeneous elements with respect to the parameter that controls the topology of the potential function and the bistability of each element. In particular, we quantify the effects of the nonhomogeneity on the onset of oscillations and the response of the network to external (assumed to be constant and very small) perturbations, using our (recently developed) coupled core fluxgate magnetometer as a representative system. The potential applications of this work include signal detection and characterization for a large class of sensor systems.

  10. A minimal model of burst-noise induced bistability.

    Directory of Open Access Journals (Sweden)

    Johannes Falk

    Full Text Available We investigate the influence of intrinsic noise on stable states of a one-dimensional dynamical system that shows in its deterministic version a saddle-node bifurcation between monostable and bistable behaviour. The system is a modified version of the Schlögl model, which is a chemical reaction system with only one type of molecule. The strength of the intrinsic noise is varied without changing the deterministic description by introducing bursts in the autocatalytic production step. We study the transitions between monostable and bistable behavior in this system by evaluating the number of maxima of the stationary probability distribution. We find that changing the size of bursts can destroy and even induce saddle-node bifurcations. This means that a bursty production of molecules can qualitatively change the dynamics of a chemical reaction system even when the deterministic description remains unchanged.

  11. Mathematical modeling of Myosin induced bistability of Lamellipodial fragments.

    Science.gov (United States)

    Hirsch, S; Manhart, A; Schmeiser, C

    2017-01-01

    For various cell types and for lamellipodial fragments on flat surfaces, externally induced and spontaneous transitions between symmetric nonmoving states and polarized migration have been observed. This behavior is indicative of bistability of the cytoskeleton dynamics. In this work, the Filament Based Lamellipodium Model (FBLM), a two-dimensional, anisotropic, two-phase continuum model for the dynamics of the actin filament network in lamellipodia, is extended by a new description of actin-myosin interaction. For appropriately chosen parameter values, the resulting model has bistable dynamics with stable states showing the qualitative features observed in experiments. This is demonstrated by numerical simulations and by an analysis of a strongly simplified version of the FBLM with rigid filaments and planar lamellipodia at the cell front and rear.

  12. Waterbomb base: a symmetric single-vertex bistable origami mechanism

    International Nuclear Information System (INIS)

    Hanna, Brandon H; Lund, Jason M; Magleby, Spencer P; Howell, Larry L; Lang, Robert J

    2014-01-01

    The origami waterbomb base is a single-vertex bistable origami mechanism that has unique properties which may prove useful in a variety of applications. It also shows promise as a test bed for smart materials and actuation because of its straightforward geometry and multiple phases of motion, ranging from simple to more complex. This study develops a quantitative understanding of the symmetric waterbomb base's kinetic behavior. This is done by completing kinematic and potential energy analyses to understand and predict bistable behavior. A physical prototype is constructed and tested to validate the results of the analyses. Finite element and virtual work analyses based on the prototype are used to explore the locations of the stable equilibrium positions and the force–deflection response. The model results are verified through comparisons to measurements on a physical prototype. The resulting models describe waterbomb base behavior and provide an engineering tool for application development. (paper)

  13. Novel piezoelectric bistable oscillator architecture for wideband vibration energy harvesting

    International Nuclear Information System (INIS)

    Liu, W Q; Badel, A; Formosa, F; Wu, Y P; Agbossou, A

    2013-01-01

    Bistable vibration energy harvesters are attracting more and more interest because of their capability to scavenge energy over a large frequency band. The bistable effect is usually based on magnetic interaction or buckled beams. This paper presents a novel architecture based on amplified piezoelectric structures. This buckled spring–mass architecture allows the energy of the dynamic mass to be converted into electrical energy in the piezoelectric materials as efficiently as possible. Modeling and design are performed and a normalized expression of the harvester behavior is given. Chirp and band-limited noise excitations are used to evaluate the proposed harvester’s performances. Simulation and experimental results are in good agreement. A method of using a spectrum plot for investigating the interwell motion is presented. The effect of the electric load impedance matching strategy is also studied. Results and comparisons with the literature show that the proposed device combines a large bandwidth and a high power density. (paper)

  14. Bistable dark solitons of a cubic-quintic Helmholtz equation

    International Nuclear Information System (INIS)

    Christian, J. M.; McDonald, G. S.; Chamorro-Posada, P.

    2010-01-01

    We provide a report on exact analytical bistable dark spatial solitons of a nonlinear Helmholtz equation with a cubic-quintic refractive-index model. Our analysis begins with an investigation of the modulational instability characteristics of Helmholtz plane waves. We then derive a dark soliton by mapping the desired asymptotic form onto a uniform background field and obtain a more general solution by deploying rotational invariance laws in the laboratory frame. The geometry of the new soliton is explored in detail, and a range of new physical predictions is uncovered. Particular attention is paid to the unified phenomena of arbitrary-angle off-axis propagation and nondegenerate bistability. Crucially, the corresponding solution of paraxial theory emerges in a simultaneous multiple limit. We conclude with a set of computer simulations that examine the role of Helmholtz dark solitons as robust attractors.

  15. Internal optical bistability of quasi-two-dimensional semiconductor nanoheterostructures

    Science.gov (United States)

    Derevyanchuk, Oleksandr V.; Kramar, Natalia K.; Kramar, Valeriy M.

    2018-01-01

    We represent the results of numerical computations of the frequency and temperature domains of possible realization of internal optical bistability in flat quasi-two-dimensional semiconductor nanoheterostructures with a single quantum well (i.e., nanofilms). Particular computations have been made for a nanofilm of layered semiconductor PbI2 embedded in dielectric medium, i.e. ethylene-methacrylic acid (E-MAA) copolymer. It is shown that an increase in the nanofilm's thickness leads to a long-wave shift of the frequency range of the manifestation the phenomenon of bistability, to increase the size of the hysteresis loop, as well as to the expansion of the temperature interval at which the realization of this phenomenon is possible.

  16. Controllable optical bistability and multistability in asymmetric double quantum wells via spontaneously generated coherence

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yuan; Deng, Li [Department of Applied Physics, East China Jiaotong University, Nanchang, 330013 (China); Chen, Aixi, E-mail: aixichen@ecjtu.jx.cn [Department of Applied Physics, East China Jiaotong University, Nanchang, 330013 (China); Institute for Quantum Computing, University of Waterloo, Ontario N2L 3G1 (Canada)

    2015-02-15

    We investigate the nonlinear optical phenomena of the optical bistability and multistability via spontaneously generated coherence in an asymmetric double quantum well structure coupled by a weak probe field and a controlling field. It is shown that the threshold and hysteresis cycle of the optical bistability can be conveniently controlled only by adjusting the intensity of the SGC or the controlling field. Moreover, switching between optical bistability and multistability can be achieved. These studies may have practical significance for the preparation of optical bistable switching device.

  17. Controllable optical bistability and multistability in asymmetric double quantum wells via spontaneously generated coherence

    International Nuclear Information System (INIS)

    Chen, Yuan; Deng, Li; Chen, Aixi

    2015-01-01

    We investigate the nonlinear optical phenomena of the optical bistability and multistability via spontaneously generated coherence in an asymmetric double quantum well structure coupled by a weak probe field and a controlling field. It is shown that the threshold and hysteresis cycle of the optical bistability can be conveniently controlled only by adjusting the intensity of the SGC or the controlling field. Moreover, switching between optical bistability and multistability can be achieved. These studies may have practical significance for the preparation of optical bistable switching device

  18. A Redox-Active Bistable Molecular Switch Mounted inside a Metal-Organic Framework.

    Science.gov (United States)

    Chen, Qishui; Sun, Junling; Li, Peng; Hod, Idan; Moghadam, Peyman Z; Kean, Zachary S; Snurr, Randall Q; Hupp, Joseph T; Farha, Omar K; Stoddart, J Fraser

    2016-11-02

    We describe the incorporation of a bistable mechanically interlocked molecule (MIM) into a robust Zr-based metal-organic framework (MOF), NU-1000, by employing a post-synthetic functionalization protocol. On average, close to two bistable [2]catenanes can be incorporated per repeating unit of the hexagonal channels of NU-1000. The reversible redox-switching of the bistable [2]catenanes is retained inside the MOF, as evidenced by solid-state UV-vis-NIR reflectance spectroscopy and cyclic voltammetry. This research demonstrates that bistable MIMs are capable of exhibiting robust dynamics inside the nanopores of a MOF.

  19. Modeling Bistable Composite Laminates for Piezoelectric Morphing Structures

    OpenAIRE

    Darryl V. Murray; Oliver J. Myers

    2013-01-01

    A sequential modeling effort for bistable composite laminates for piezoelectric morphing structures is presented. Thin unsymmetric carbon fiber composite laminates are examined for use of morphing structures using piezoelectric actuation. When cooling from the elevated cure temperature to room temperature, these unsymmetric composite laminates will deform. These postcure room temperature deformation shapes can be used as morphing structures. Applying a force to these deformed laminates will c...

  20. Spatial effect on stochastic dynamics of bistable evolutionary games

    International Nuclear Information System (INIS)

    So, Kohaku H Z; Ohtsuki, Hisashi; Kato, Takeo

    2014-01-01

    We consider the lifetimes of metastable states in bistable evolutionary games (coordination games), and examine how they are affected by spatial structure. A semiclassical approximation based on a path integral method is applied to stochastic evolutionary game dynamics with and without spatial structure, and the lifetimes of the metastable states are evaluated. It is shown that the population dependence of the lifetimes is qualitatively different in these two models. Our result indicates that spatial structure can accelerate the transitions between metastable states. (paper)

  1. Dynamic optical bistability in resonantly enhanced Raman generation

    International Nuclear Information System (INIS)

    Novikova, I.; Phillips, D.F.; Zibrov, A.S.; Andre, A.; Walsworth, R.L.

    2004-01-01

    We report observations of novel dynamic behavior in resonantly enhanced stimulated Raman scattering in Rb vapor. In particular, we demonstrate a dynamic hysteresis of the Raman scattered optical field in response to changes of the drive laser field intensity and/or frequency. This effect may be described as a dynamic form of optical bistability resulting from the formation and decay of atomic coherence. We have applied this phenomenon to the realization of an all-optical switch

  2. A Precise Temperature-Responsive Bistable Switch Controlling Yersinia Virulence.

    Science.gov (United States)

    Nuss, Aaron Mischa; Schuster, Franziska; Roselius, Louisa; Klein, Johannes; Bücker, René; Herbst, Katharina; Heroven, Ann Kathrin; Pisano, Fabio; Wittmann, Christoph; Münch, Richard; Müller, Johannes; Jahn, Dieter; Dersch, Petra

    2016-12-01

    Different biomolecules have been identified in bacterial pathogens that sense changes in temperature and trigger expression of virulence programs upon host entry. However, the dynamics and quantitative outcome of this response in individual cells of a population, and how this influences pathogenicity are unknown. Here, we address these questions using a thermosensing virulence regulator of an intestinal pathogen (RovA of Yersinia pseudotuberculosis) as a model. We reveal that this regulator is part of a novel thermoresponsive bistable switch, which leads to high- and low-invasive subpopulations within a narrow temperature range. The temperature range in which bistability is observed is defined by the degradation and synthesis rate of the regulator, and is further adjustable via a nutrient-responsive regulator. The thermoresponsive switch is also characterized by a hysteretic behavior in which activation and deactivation occurred on vastly different time scales. Mathematical modeling accurately mirrored the experimental behavior and predicted that the thermoresponsiveness of this sophisticated bistable switch is mainly determined by the thermo-triggered increase of RovA proteolysis. We further observed RovA ON and OFF subpopulations of Y. pseudotuberculosis in the Peyer's patches and caecum of infected mice, and that changes in the RovA ON/OFF cell ratio reduce tissue colonization and overall virulence. This points to a bet-hedging strategy in which the thermoresponsive bistable switch plays a key role in adapting the bacteria to the fluctuating conditions encountered as they pass through the host's intestinal epithelium and suggests novel strategies for the development of antimicrobial therapies.

  3. A Precise Temperature-Responsive Bistable Switch Controlling Yersinia Virulence.

    Directory of Open Access Journals (Sweden)

    Aaron Mischa Nuss

    2016-12-01

    Full Text Available Different biomolecules have been identified in bacterial pathogens that sense changes in temperature and trigger expression of virulence programs upon host entry. However, the dynamics and quantitative outcome of this response in individual cells of a population, and how this influences pathogenicity are unknown. Here, we address these questions using a thermosensing virulence regulator of an intestinal pathogen (RovA of Yersinia pseudotuberculosis as a model. We reveal that this regulator is part of a novel thermoresponsive bistable switch, which leads to high- and low-invasive subpopulations within a narrow temperature range. The temperature range in which bistability is observed is defined by the degradation and synthesis rate of the regulator, and is further adjustable via a nutrient-responsive regulator. The thermoresponsive switch is also characterized by a hysteretic behavior in which activation and deactivation occurred on vastly different time scales. Mathematical modeling accurately mirrored the experimental behavior and predicted that the thermoresponsiveness of this sophisticated bistable switch is mainly determined by the thermo-triggered increase of RovA proteolysis. We further observed RovA ON and OFF subpopulations of Y. pseudotuberculosis in the Peyer's patches and caecum of infected mice, and that changes in the RovA ON/OFF cell ratio reduce tissue colonization and overall virulence. This points to a bet-hedging strategy in which the thermoresponsive bistable switch plays a key role in adapting the bacteria to the fluctuating conditions encountered as they pass through the host's intestinal epithelium and suggests novel strategies for the development of antimicrobial therapies.

  4. Stochastic dynamics of a delayed bistable system with multiplicative noise

    Energy Technology Data Exchange (ETDEWEB)

    Dung, Nguyen Tien, E-mail: dung-nguyentien10@yahoo.com, E-mail: dungnt@fpt.edu.vn [Department of Mathematics, FPT University, No 8 Ton That Thuyet, My Dinh, Tu Liem, Hanoi (Viet Nam)

    2014-05-15

    In this paper we investigate the properties of a delayed bistable system under the effect of multiplicative noise. We first prove the existence and uniqueness of the positive solution and show that its moments are uniformly bounded. Then, we study stochastic dynamics of the solution in long time, the lower and upper bounds for the paths and an estimate for the average value are provided.

  5. Traveling waves in the discrete fast buffered bistable system.

    Science.gov (United States)

    Tsai, Je-Chiang; Sneyd, James

    2007-11-01

    We study the existence and uniqueness of traveling wave solutions of the discrete buffered bistable equation. Buffered excitable systems are used to model, among other things, the propagation of waves of increased calcium concentration, and discrete models are often used to describe the propagation of such waves across multiple cells. We derive necessary conditions for the existence of waves, and, under some restrictive technical assumptions, we derive sufficient conditions. When the wave exists it is unique and stable.

  6. Bistable flapping of flexible flyers in oscillatory flow

    Science.gov (United States)

    Huang, Yangyang; Kanso, Eva

    2016-11-01

    Biological and bio-inspired flyers move by shape actuation. The direct control of shape variables for locomotory purposes is well studied. Less is known about indirect shape actuation via the fluid medium. Here, we consider a flexible Λ-flyer in oscillatory flow that is free to flap and rotate around its fixed apex. We study its motion in the context of the inviscid vortex sheet model. We first analyze symmetric flapping about the vertical axis of gravity. We find that there is a finite value of the flexibility that maximizes both the flapping amplitude and elastic energy storage. Our results show that rather than resonance, the flyer relies on fluidic effects to optimize these two quantities. We then perturb the flyer away from the vertical and analyze its stability. Four distinct types of rolling behavior are identified: mono-stable, bistable, bistable oscillatory rotations and chaotic dynamics. We categorize these types of behavior in terms of the flyer's and flow parameters. In particular, the transition from mono-stable to bistable behavior occurs at a constant value of the product of the flow amplitude and acceleration. This product can be interpreted as the ratio of fluidic drag to gravity, confirming the fluid role in this transition.

  7. Interplay of bistable kinetics of gene expression during cellular growth

    International Nuclear Information System (INIS)

    Zhdanov, Vladimir P

    2009-01-01

    In cells, the bistable kinetics of gene expression can be observed on the level of (i) one gene with positive feedback between protein and mRNA production, (ii) two genes with negative mutual feedback between protein and mRNA production, or (iii) in more complex cases. We analyse the interplay of two genes of type (ii) governed by a gene of type (i) during cellular growth. In particular, using kinetic Monte Carlo simulations, we show that in the case where gene 1, operating in the bistable regime, regulates mutually inhibiting genes 2 and 3, also operating in the bistable regime, the latter genes may eventually be trapped either to the state with high transcriptional activity of gene 2 and low activity of gene 3 or to the state with high transcriptional activity of gene 3 and low activity of gene 2. The probability to get to one of these states depends on the values of the model parameters. If genes 2 and 3 are kinetically equivalent, the probability is equal to 0.5. Thus, our model illustrates how different intracellular states can be chosen at random with predetermined probabilities. This type of kinetics of gene expression may be behind complex processes occurring in cells, e.g., behind the choice of the fate by stem cells

  8. Bistable switches control memory and plasticity in cellular differentiation

    Science.gov (United States)

    Wang, Lei; Walker, Brandon L.; Iannaccone, Stephen; Bhatt, Devang; Kennedy, Patrick J.; Tse, William T.

    2009-01-01

    Development of stem and progenitor cells into specialized tissues in multicellular organisms involves a series of cell fate decisions. Cellular differentiation in higher organisms is generally considered irreversible, and the idea of developmental plasticity in postnatal tissues is controversial. Here, we show that inhibition of mitogen-activated protein kinase (MAPK) in a human bone marrow stromal cell-derived myogenic subclone suppresses their myogenic ability and converts them into satellite cell-like precursors that respond to osteogenic stimulation. Clonal analysis of the induced osteogenic response reveals ultrasensitivity and an “all-or-none” behavior, hallmarks of a bistable switch mechanism with stochastic noise. The response demonstrates cellular memory, which is contingent on the accumulation of an intracellular factor and can be erased by factor dilution through cell divisions or inhibition of protein synthesis. The effect of MAPK inhibition also exhibits memory and appears to be controlled by another bistable switch further upstream that determines cell fate. Once the memory associated with osteogenic differentiation is erased, the cells regain their myogenic ability. These results support a model of cell fate decision in which a network of bistable switches controls inducible production of lineage-specific differentiation factors. A competitive balance between these factors determines cell fate. Our work underscores the dynamic nature of cellular differentiation and explains mechanistically the dual properties of stability and plasticity associated with the process. PMID:19366677

  9. Brain mechanisms for simple perception and bistable perception.

    Science.gov (United States)

    Wang, Megan; Arteaga, Daniel; He, Biyu J

    2013-08-27

    When faced with ambiguous sensory inputs, subjective perception alternates between the different interpretations in a stochastic manner. Such multistable perception phenomena have intrigued scientists and laymen alike for over a century. Despite rigorous investigations, the underlying mechanisms of multistable perception remain elusive. Recent studies using multivariate pattern analysis revealed that activity patterns in posterior visual areas correlate with fluctuating percepts. However, increasing evidence suggests that vision--and perception at large--is an active inferential process involving hierarchical brain systems. We applied searchlight multivariate pattern analysis to functional magnetic resonance imaging signals across the human brain to decode perceptual content during bistable perception and simple unambiguous perception. Although perceptually reflective activity patterns during simple perception localized predominantly to posterior visual regions, bistable perception involved additionally many higher-order frontoparietal and temporal regions. Moreover, compared with simple perception, both top-down and bottom-up influences were dramatically enhanced during bistable perception. We further studied the intermittent presentation of ambiguous images--a condition that is known to elicit perceptual memory. Compared with continuous presentation, intermittent presentation recruited even more higher-order regions and was accompanied by further strengthened top-down influences but relatively weakened bottom-up influences. Taken together, these results strongly support an active top-down inferential process in perception.

  10. Experimental chaotic quantification in bistable vortex induced vibration systems

    Science.gov (United States)

    Huynh, B. H.; Tjahjowidodo, T.

    2017-02-01

    The study of energy harvesting by means of vortex induced vibration systems has been initiated a few years ago and it is considered to be potential as a low water current energy source. The energy harvester is realized by exposing an elastically supported blunt structure under water flow. However, it is realized that the system will only perform at a limited operating range (water flow) that is attributed to the resonance phenomenon that occurs only at a frequency that corresponds to the fluid flow. An introduction of nonlinear elements seems to be a prominent solution to overcome the problem. Among many nonlinear elements, a bistable spring is known to be able to improve the harvested power by a vortex induced vibrations (VIV) based energy converter at the low velocity water flows. However, it is also observed that chaotic vibrations will occur at different operating ranges that will erratically diminish the harvested power and cause a difficulty in controlling the system that is due to the unpredictability in motions of the VIV structure. In order to design a bistable VIV energy converter with improved harvested power and minimum negative effect of chaotic vibrations, the bifurcation map of the system for varying governing parameters is highly on demand. In this study, chaotic vibrations of a VIV energy converter enhanced by a bistable stiffness element are quantified in a wide range of the governing parameters, i.e. damping and bistable gap. Chaotic vibrations of the bistable VIV energy converter are simulated by utilization of a wake oscillator model and quantified based on the calculation of the Lyapunov exponent. Ultimately, a series of experiments of the system in a water tunnel, facilitated by a computer-based force-feedback testing platform, is carried out to validate the existence of chaotic responses. The main challenge in dealing with experimental data is in distinguishing chaotic response from noise-contaminated periodic responses as noise will smear

  11. D0 Central Tracking Solenoid Energization, Controls, Interlocks and Quench Protection Operating Procedures

    International Nuclear Information System (INIS)

    Hance, R.

    1998-01-01

    This procedure is used when it is necessary to operate the solenoid energization, controls, interlocks and quench detection system. Note that a separate procedure exists for operating the solenoid 'cryogenic' systems. Only D0 Control Room Operators or the Project Electrical Engineer are qualified to execute these procedures or operate the solenoid system. This procedure assumes that the operator is familiar with using the Distributed Manufacturing Automation and Control Software (DMACS).

  12. A simple formula for emittance growth due to spherical aberration in a solenoid lens

    International Nuclear Information System (INIS)

    Kumar, V.; Phadte, D.; Patidar, C.B.

    2011-01-01

    We analyse the beam dynamics in a solenoid without the paraxial approximation, including up to the fifth order term in the radial displacement. We use this analysis to derive expressions for the coefficients of spherical aberration in terms of the on-axis field profile of the solenoid. Under the thin lens approximation, a simple formula is derived for the growth of rms emittance resulting due to spherical aberration in a solenoid. (author)

  13. Generation of ten kilotesla longitudinal magnetic fields in ultraintense laser-solenoid target interactions

    OpenAIRE

    Xiao, K. D.; Zhou, C. T.; Zhang, H.; Huang, T. W.; Li, R.; Qiao, B.; Cao, J. M.; Cai, T. X.; Ruan, S. C.; He, X. T.

    2018-01-01

    Production of the huge longitudinal magnetic fields by using an ultraintense laser pulse irradiating a solenoid target is considered. Through three-dimensional particle-in-cell simulations, it is shown that the longitudinal magnetic field up to ten kilotesla can be observed in the ultraintense laser-solenoid target interactions. The finding is associated with both fast and return electron currents in the solenoid target. The huge longitudinal magnetic field is of interest for a number of impo...

  14. Design of an elliptical solenoid magnet for transverse beam matching to the spiral inflector

    International Nuclear Information System (INIS)

    Goswami, A.; Sing Babu, P.; Pandit, V.S.

    2013-01-01

    In this work, we present the design study of an elliptical solenoid magnet to be used for transverse beam matching at the input of a spiral inflector for efficient transmission. We have studied the dependence of axial field and gradients in the transverse directions of the elliptical solenoid magnet with ellipticity of the aperture. Using the beam envelope equations we have studied the feasibility of using an elliptical solenoid for transverse beam matching to the acceptance of a spiral inflector. (author)

  15. Solenoidal Fields for Ion Beam Transport and Focusing

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Edward P.; Leitner, Matthaeus

    2007-11-01

    In this report we calculate time-independent fields of solenoidal magnets that are suitable for ion beam transport and focusing. There are many excellent Electricity and Magnetism textbooks that present the formalism for magnetic field calculations and apply it to simple geometries [1-1], but they do not include enough relevant detail to be used for designing a charged particle transport system. This requires accurate estimates of fringe field aberrations, misaligned and tilted fields, peak fields in wire coils and iron, external fields, and more. Specialized books on magnet design, technology, and numerical computations [1-2] provide such information, and some of that is presented here. The AIP Conference Proceedings of the US Particle Accelerator Schools [1-3] contain extensive discussions of design and technology of magnets for ion beams - except for solenoids. This lack may be due to the fact that solenoids have been used primarily to transport and focus particles of relatively low momenta, e.g. electrons of less than 50 MeV and protons or H- of less than 1.0 MeV, although this situation may be changing with the commercial availability of superconducting solenoids with up to 20T bore field [1-4]. Internal reports from federal laboratories and industry treat solenoid design in detail for specific applications. The present report is intended to be a resource for the design of ion beam drivers for Inertial Fusion Energy [1-5] and Warm Dense Matter experiments [1-6], although it should also be useful for a broader range of applications. The field produced by specified currents and material magnetization can always be evaluated by solving Maxwell's equations numerically, but it is also desirable to have reasonably accurate, simple formulas for conceptual system design and fast-running beam dynamics codes, as well as for general understanding. Most of this report is devoted to such formulas, but an introduction to the Tosca{copyright} code [1-7] and some

  16. Solenoidal Fields for Ion Beam Transport and Focusing

    International Nuclear Information System (INIS)

    Lee, Edward P.; Leitner, Matthaeus

    2007-01-01

    In this report we calculate time-independent fields of solenoidal magnets that are suitable for ion beam transport and focusing. There are many excellent Electricity and Magnetism textbooks that present the formalism for magnetic field calculations and apply it to simple geometries (1-1), but they do not include enough relevant detail to be used for designing a charged particle transport system. This requires accurate estimates of fringe field aberrations, misaligned and tilted fields, peak fields in wire coils and iron, external fields, and more. Specialized books on magnet design, technology, and numerical computations (1-2) provide such information, and some of that is presented here. The AIP Conference Proceedings of the US Particle Accelerator Schools (1-3) contain extensive discussions of design and technology of magnets for ion beams - except for solenoids. This lack may be due to the fact that solenoids have been used primarily to transport and focus particles of relatively low momenta, e.g. electrons of less than 50 MeV and protons or H- of less than 1.0 MeV, although this situation may be changing with the commercial availability of superconducting solenoids with up to 20T bore field (1-4). Internal reports from federal laboratories and industry treat solenoid design in detail for specific applications. The present report is intended to be a resource for the design of ion beam drivers for Inertial Fusion Energy (1-5) and Warm Dense Matter experiments (1-6), although it should also be useful for a broader range of applications. The field produced by specified currents and material magnetization can always be evaluated by solving Maxwell's equations numerically, but it is also desirable to have reasonably accurate, simple formulas for conceptual system design and fast-running beam dynamics codes, as well as for general understanding. Most of this report is devoted to such formulas, but an introduction to the Tosca(copyright) code (1-7) and some numerical

  17. Design and fabrication of the PDX poloidal field solenoid utilizing fiberglass reinforced epoxy

    International Nuclear Information System (INIS)

    Young, K.S.C.

    1975-11-01

    This paper discusses the basic design of the Poloidal Field Solenoid Coil. It will be mainly concerned with the more unique features of the Solenoid such as the copper coil windings and the design of the epoxy-glass structural support mandrels. The center solenoid coil of the PDX machine consists of five different coil systems (OH No. 8, No. 9; NF No. 11; DF No. 7; EF Solenoid and CF No. 9). Three concentric fiberglass reinforced epoxy cylinders fabricated in-house will act as mandrels to support and to house the coils that will result as an integral unit

  18. Beam dynamics of the interaction region solenoid in a linear collider due to a crossing angle

    Directory of Open Access Journals (Sweden)

    P. Tenenbaum

    2003-06-01

    Full Text Available Future linear colliders may require a nonzero crossing angle between the two beams at the interaction point (IP. This requirement in turn implies that the beams will pass through the strong interaction region solenoid with an angle, and thus that the component of the solenoidal field perpendicular to the beam trajectory is nonzero. The interaction of the beam and the solenoidal field in the presence of a crossing angle will cause optical effects not observed for beams passing through the solenoid on axis; these effects include dispersion, deflection of the beam, and synchrotron radiation effects. For a purely solenoidal field, the optical effects which are relevant to luminosity exactly cancel at the IP when the influence of the solenoid’s fringe field is taken into account. Beam size growth due to synchrotron radiation in the solenoid is proportional to the fifth power of the product of the solenoidal field, the length of the solenoid, and the crossing angle. Examples based on proposed linear collider detector solenoid configurations are presented.

  19. Detection circuit of solenoid valve operation and control rod drive mechanism utilizing the circuit

    International Nuclear Information System (INIS)

    Ono, Takehiko.

    1976-01-01

    Object: To detect the operation of a plunger and detect opening and closing operations of a solenoid valve driving device due to change in impedance of a coil for driving the solenoid valve to judge normality and abnormality of the solenoid valve, thereby increasing reliance and safety of drive and control apparatus of control rods. Structure: An arrangement comprises a drive and operation detector section wherein the operation of a solenoid driving device for controlling power supply to a coil for driving the solenoid valve to control opening and closing of the solenoid valve, and a plunger operation detector section for detecting change in impedance of the drive coil to detect that the plunger of the solenoid valve is either in the opening direction or closing direction, whereby a predetermined low voltage such as not to activate the solenoid valve even when the solenoid valve is open or closed is applied to detect a current flowing into the coil at that time, thus detecting an operating state of the plunger. (Yoshino, Y.)

  20. Analysis of electromagnetic field of direct action solenoid valve with current changing

    International Nuclear Information System (INIS)

    Liu Qianfeng; Bo Hanliang; Qin Benke

    2009-01-01

    Control rod hydraulic drive mechanism(CRHDM) is a newly invented patent of Institute of Nuclear and New Energy Technology of Tsinghua University. The direct action solenoid valve is the key part of this technology, so the performance of the solenoid valve directly affects the function of the CRHDM. With the current and the air gap changing,the electromagnetic field of the direct action solenoid valve was analyzed using the ANSYS software,which was validated by the experiment. The result shows that the electromagnetic force of the solenoid valve increases with the current increasing or the gap between the two armatures decreasing. Further more, the working current was confirmed. (authors)

  1. What caused the failures of the solenoid valve screws

    International Nuclear Information System (INIS)

    Vassallo, T.P.; Mumford, J.R.; Hossain, F.

    2001-01-01

    At Seabrook Station on May 5,1998 following a lengthy purge of the pressurizer steam space through Containment isolation sample valve 1-RC-FV-2830, the UL status light associated with this solenoid valve did not come on when the valve was closed from the plant's main control board. The UL status light is used to confirm valve closure position to satisfy the plant's Technical Specification requirements. The incorrect valve position indication on the main control board was initially believed to have resulted from excessive heat from a failed voltage control module that did not reduce the voltage to the valve's solenoid coil. This conclusion was based on a similar event that occurred in November of 1996. Follow-up in-plant testing of the valve determined that the voltage control module had not failed and was functioning satisfactorily. Subsequent investigations determined the root cause of the event to be excessive heat-up of the valve caused by high process fluid temperature and an excessively long purge of the pressurizer. The excessive heat-up of the valve from the high temperature process fluid weakened the magnetic field strength of the valve stem magnet to the extent that the UL status light reed switch would not actuate when the valve was closed. Since the voltage control module was tested and found to be functioning properly it was not replaced. Only the UL status light reed switch was replaced with a more sensitive reed that would respond better to a reduced magnetic field strength that results from a hot magnet. During reed switch replacement, three terminal block screws in the valve housing were found fractured and three other terminal block screws fractured during determination of the electrical conductors. This paper describes the initial plant event and ensuing laboratory tests and examinations that were performed to determine the root cause of the failure of the terminal block screws from the Containment isolation sample solenoid valve. (author)

  2. Gas-mixing system for drift chambers using solenoid valves

    International Nuclear Information System (INIS)

    Cooper, W.E.; Sugano, K.; Trentlage, D.B.

    1983-04-01

    We describe an inexpensive system for mixing argon and ethane drift chamber gas which is used for the E-605 experiment at Fermilab. This system is based on the idea of intermittent mixing of gases with fixed mixing flow rates. A dual-action pressure switch senses the pressure in a mixed gas reservoir tank and operates solenoid valves to control mixing action and regulate reservoir pressure. This system has the advantages that simple controls accurately regulate the mixing ratio and that the mixing ratio is nearly flow rate independent. We also report the results of the gas analysis of various samplings, and the reliability of the system in long-term running

  3. Test Results for HINS Focusing Solenoids at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Tartaglia, M.A.; Orris, D.F.; Terechkine, I.; Tompkins, J.C.; /Fermilab

    2008-08-01

    A focusing lens R&D program is close to completion and industrial production of magnets has begun. Two types of magnets are being built for use in the room temperature RF section at the front end of a superconducting H-minus linac of a High Intensity Neutrino Source. All of the magnets are designed as a solenoid with bucking coils to cancel the field in the vicinity of adjacent RF cavities, and one type incorporates steering dipole corrector coils. We present a summary of the predicted and measured quench and magnetic properties for both R&D and production device samples that have been tested at Fermilab.

  4. Solenoid fringe field compensation for the Cluster Klystron

    International Nuclear Information System (INIS)

    Wang, H.; Fernow, R.C.; Kirk, H.G.; Palmer, R.B.; Zhao, Y.

    1996-04-01

    Optimization of the solenoid pancake currents so as to have a uniform axial magnetic field over an extended volume, is very important for the successful operation of the Cluster Klystron. By boosting the first and the last pancake currents by 35%, a uniform field Br/Bz ≤ 0.1% at radius R ≤ 2 cm can be extended from ± 7 cm to ± 16 cm. The result confirms simulations and the requirements for a 3-beam Cluster Klystron Experiment are achieved

  5. A spectrometer using one or two superconducting coaxial solenoids

    International Nuclear Information System (INIS)

    Schapira, J.P.; Gales, S.; Laurent, J.P.

    1979-06-01

    A set of two superconducting solenoidal coils which are presently under construction at the Orsay I.P.N. is described. Because of its optical properties, the system can be used as spectrometer: focusing properties with small geometrical aberrations allowing large solid angles to be used together with good transmission and isochronism. Various types of experiments can be envisaged with such a device: angular correlation at zero degree, study of rare events like exotic reactions, time of flight for mass identification and rapid (much less than 1 μs) and efficient collection of radioactive nuclei for subsequent spectroscopy measurements [fr

  6. Mechanical design of a 250 kilogauss solenoidal magnet

    International Nuclear Information System (INIS)

    Bonanos, P.

    1975-12-01

    The mechanical design and construction of a 5 cm bore, 23 cm long solenoidal magnet operated at 250 kilogauss is described. The magnet provides confining field for a plasma heated by a CO 2 laser. Radial diagnostic ports with a clear aperture of 0.41 cm allow viewing access near the magnet midplane. The on-axis field homogeneity is within 5 percent over a central length of 12 cm. The magnet sustained 500 to 1000 pulses at the highest field levels before catastrophic failure

  7. The Mechanical Design Optimization of a High Field HTS Solenoid

    Energy Technology Data Exchange (ETDEWEB)

    Lalitha, SL; Gupta, RC

    2015-06-01

    This paper describes the conceptual design optimization of a large aperture, high field (24 T at 4 K) solenoid for a 1.7 MJ superconducting magnetic energy storage device. The magnet is designed to be built entirely of second generation (2G) high temperature superconductor tape with excellent electrical and mechanical properties at the cryogenic temperatures. The critical parameters that govern the magnet performance are examined in detail through a multiphysics approach using ANSYS software. The analysis results formed the basis for the performance specification as well as the construction of the magnet.

  8. An earthworm-like actuator using segmented solenoids

    International Nuclear Information System (INIS)

    Shin, Bu Hyun; Choi, Seung-Wook; Lee, Seung-Yop; Bang, Young-Bong

    2011-01-01

    A biomimetic actuator is developed using four segmented solenoids mimicking earthworm locomotion. The proposed actuator not only has a simple structure composed of cores and coils, but also enables bi-directional actuation and high speed locomotion regardless of friction conditions. We have implemented theoretical analysis to design the optimal profiles of input current signal for maximum speed and predict the output force and stroke. Experiments using a prototype show that the earthworm-like actuator travels with a speed above 60 mm s −1 regardless of friction conditions

  9. HB+ prepares for insertion into the CMS solenoid

    CERN Multimedia

    Dave Barney, CERN

    2006-01-01

    With calibration of the first half of the barrel Hadron Calorimeter (HB+) complete (using a radioactive source), preparations begin for its insertion into the solenoid for the Magnet Test and Cosmic Challenge (MTCC). It was moved out of its alcove at the beginning of March - a non-trivial (but completely successful) operation due to the proximity of one of the barrel yoke rings (YB+1). The other half of the barrel Hadron Calorimeter (HB-) and one of the endcaps (HE+) should also be calibrated before the MTCC.

  10. Bistable optical response of a nanoparticle heterodimer : Mechanism, phase diagram, and switching time

    NARCIS (Netherlands)

    Nugroho, Bintoro; Iskandar, Alexander; Malyshev, V.A.; Knoester, Jasper

    2013-01-01

    We conduct a theoretical study of the bistable optical response of a nanoparticle heterodimer comprised of a closely spaced semiconductor quantum dot and a metal nanoparticle. The bistable nature of the response results from the interplay between the quantum dot's optical nonlinearity and its

  11. Optical bistability in Er-Yb codoped phosphate glass microspheres at room temperature

    NARCIS (Netherlands)

    Warda, Jonathan M.; O'Shea, Danny G.; Shortt, Brian J.; Chormaic, Sile Nic

    2007-01-01

    We experimentally demonstrate optical bistability in Er(3+)-Yb(3+) phosphate glass microspheres at 295 K. Bistability is associated with both Er(3+) fluorescence and lasing behavior, and chromatic switching. The chromatic switching results from an intrinsic mechanism exploiting the thermal coupling

  12. Take it of leave it : Mechanisms underlying bacterial bistable regulatory networks

    NARCIS (Netherlands)

    Siebring, Jeroen; Sorg, Robin; Herber, Martijn; Kuipers, Oscar; Filloux, Alain A.M.

    2012-01-01

    Bistable switches occur in regulatory networks that can exist in two distinct stable states. Such networks allow distinct switching of individual cells. In bacteria these switches coexist with regulatory networks that respond gradually to environmental input. Bistable switches play key roles in high

  13. Configurational rearrangements of bistable centers in covalent semiconductors - phase transitions of the second type

    International Nuclear Information System (INIS)

    Ivanyukovich, V.A.; Karas', V.I.; Lomako, V.M.

    1989-01-01

    A new radiation configurational-bistable defect diffring from the known similar defects by the fact that it possessestemperature inversion of states is detected in gallium arsenide. Configurational-bistable rearrangements are shown to be considered as phase transitions of the second type

  14. Bistable traveling waves for a competitive-cooperative system with nonlocal delays

    Science.gov (United States)

    Tian, Yanling; Zhao, Xiao-Qiang

    2018-04-01

    This paper is devoted to the study of bistable traveling waves for a competitive-cooperative reaction and diffusion system with nonlocal time delays. The existence of bistable waves is established by appealing to the theory of monotone semiflows and the finite-delay approximations. Then the global stability of such traveling waves is obtained via a squeezing technique and a dynamical systems approach.

  15. Topical Meeting on Optical Bistability Held at Rochester, New York on 15-17 June 1983.

    Science.gov (United States)

    1983-01-01

    ThB16-1 SELF-BEATING INSTABILITIES IN BISTABLE DEVICES J.A. MARTIN-PEREDA .. M.A. MURIEL DEPARTAMENTO DE ELECTRONICA CUANTICA E.T.S. ING...OPTICAL BISTABLL SYSTEMS J.A. MARTIN PEREDA M.A. MURIEL ; DEPARTAMENIO DE ELECTRONICA CUANTICA E.T.S. ING. TELLCOMUNICACION UNIVERSIDAD POLITECNICA DE

  16. Linear population allocation by bistable switches in response to transient stimulation.

    Science.gov (United States)

    Srimani, Jaydeep K; Yao, Guang; Neu, John; Tanouchi, Yu; Lee, Tae Jun; You, Lingchong

    2014-01-01

    Many cellular decision processes, including proliferation, differentiation, and phenotypic switching, are controlled by bistable signaling networks. In response to transient or intermediate input signals, these networks allocate a population fraction to each of two distinct states (e.g. OFF and ON). While extensive studies have been carried out to analyze various bistable networks, they are primarily focused on responses of bistable networks to sustained input signals. In this work, we investigate the response characteristics of bistable networks to transient signals, using both theoretical analysis and numerical simulation. We find that bistable systems exhibit a common property: for input signals with short durations, the fraction of switching cells increases linearly with the signal duration, allowing the population to integrate transient signals to tune its response. We propose that this allocation algorithm can be an optimal response strategy for certain cellular decisions in which excessive switching results in lower population fitness.

  17. Optical bistability via quantum interference from incoherent pumping and spontaneous emission

    International Nuclear Information System (INIS)

    Sahrai, M.; Asadpour, S.H.; Sadighi-Bonabi, R.

    2011-01-01

    We theoretically investigate the optical bistability (OB) in a V-type three-level atomic system confined in a unidirectional ring cavity via incoherent pumping field. It is shown that the threshold of optical bistability can be controlled by the rate of an incoherent pumping field and by interference mechanism arising from the spontaneous emission and incoherent pumping field. We demonstrate that the optical bistability converts to optical multi-stability (OM) by the quantum interference mechanism. - Highlights: → We modulate the optical bistability (OB) in a four-level N-type atomic system. → The threshold of optical bistability can be controlled by the quantum interferences. → OB converts to optical multi-stability (OM) by the quantum interferences. → We discuss the effect of an incoherent pumping field on reduction of OB threshold.

  18. A review of the recent research on vibration energy harvesting via bistable systems

    International Nuclear Information System (INIS)

    Harne, R L; Wang, K W

    2013-01-01

    The investigation of the conversion of vibrational energy into electrical power has become a major field of research. In recent years, bistable energy harvesting devices have attracted significant attention due to some of their unique features. Through a snap-through action, bistable systems transition from one stable state to the other, which could cause large amplitude motion and dramatically increase power generation. Due to their nonlinear characteristics, such devices may be effective across a broad-frequency bandwidth. Consequently, a rapid engagement of research has been undertaken to understand bistable electromechanical dynamics and to utilize the insight for the development of improved designs. This paper reviews, consolidates, and reports on the major efforts and findings documented in the literature. A common analytical framework for bistable electromechanical dynamics is presented, the principal results are provided, the wide variety of bistable energy harvesters are described, and some remaining challenges and proposed solutions are summarized. (topical review)

  19. Analysis of an adjustable field permanent magnet solenoid

    Science.gov (United States)

    Burris-Mog, T.; Burns, M.; Chavez, A.; Schillig, J.

    2017-10-01

    A feasibility study has been performed on an adjustable-field permanent magnet (PM) solenoid concept in an effort to reduce the dependence that linear induction accelerators have on large direct current power supplies and associated cooling systems. The concept relies on the ability to reorient sections of the PMs and thus redirect their magnetization vector to either add to or subtract from the on-axis magnetic field. This study concentrated on the focal strengths and emittance growths for two different designs, both with 19 cm bore diameters extending 53 cm in length. The first design is expected to produce peak magnetic fields ranging from 260 to 900 G (0.026 to 0.09 T) while the second design is expected to produce peak magnetic fields ranging from 580 to 2100 G (0.058 to 0.21 T). Although the PM configuration generates a variable magnetic field and the torques acting on PMs within the assembly appear manageable, the emittance growth is larger than that of a DC solenoid.

  20. Design verification methodology for a solenoid valve for industrial applications

    International Nuclear Information System (INIS)

    Park, Chang Dae; Lim, Byung Ju; Chun, Kyung Yul

    2015-01-01

    Solenoid operated valves (SOV) are widely used in many applications due to their fast dynamic responses, cost effectiveness, and less contamination sensitive characteristics. In this paper, we tried to provide a convenient method of design verification of SOV to design engineers who depend on their experiences and experiment during design and development process of SOV. First, we summarize a detailed procedure for designing SOVs for industrial applications. All of the design constraints are defined in the first step of the design, and then the detail design procedure is presented based on design experiences as well as various physical and electromagnetic relationships. Secondly, we have suggested a verification method of this design using theoretical relationships, which enables optimal design of SOV from a point of view of safety factor of design attraction force. Lastly, experimental performance tests using several prototypes manufactured based on this design method show that the suggested design verification methodology is appropriate for designing new models of solenoids. We believe that this verification process is novel logic and useful to save time and expenses during development of SOV because verification tests with manufactured specimen may be substituted partly by this verification methodology.

  1. Laser heated solenoid as a neutron source facility

    International Nuclear Information System (INIS)

    Steinhauer, L.C.; Rose, P.H.

    1975-01-01

    Conceptual designs are presented for a radiation test facility based on a laser heated plasma confined in a straight solenoid. The thin plasma column, a few meters in length and less than a centimeter in diameter, serves as a line source of neutrons. Test samples are located within or just behind the plasma tube, at a radius of 1-2 cm from the axis. The plasma is heated by an axially-directed powerful long-wavelength laser beam. The plasma is confined radially in the intense magnetic field supplied by a pulsed solenoid surrounding the plasma tube. The facility is pulsed many times a second to achieve a high time-averaged neutron flux on the test samples. Based on component performance achievable in the near term (e.g., magnetic field, laser pulse energy) and assuming classical physical processes, it appears that average fluxes of 10 13 to 10 14 neutrons/cm 2 -sec can be achieved in such a device. The most severe technical problems in such a facility appear to be rapid pulsing design and lifetime of some electrical and laser components

  2. Design and analysis of a novel latch system implementing fiber-reinforced composite materials

    Science.gov (United States)

    Guevara Arreola, Francisco Javier

    The use of fiber-reinforced composite materials have increased in the last four decades in high technology applications due to their exceptional mechanical properties and low weight. In the automotive industry carbon fiber have become popular exclusively in luxury cars because of its high cost. However, Carbon-glass hybrid composites offer an effective alternative to designers to implement fiber-reinforced composites into several conventional applications without a considerable price increase maintaining most of their mechanical properties. A door latch system is a complex mechanism that is under high loading conditions during car accidents such as side impacts and rollovers. Therefore, the Department of Transportation in The United States developed a series of tests that every door latch system comply in order to be installed in a vehicle. The implementation of fiber-reinforced composite materials in a door latch system was studied by analyzing the material behavior during the FMVSS No. 206 transverse test using computational efforts and experimental testing. Firstly, a computational model of the current forkbolt and detent structure was developed. Several efforts were conducted in order to create an effective and time efficient model. Two simplified models were implemented with two different contact interaction approaches. 9 composite materials were studied in forkbolt and 5 in detent including woven carbon fiber, unidirectional carbon fiber, woven carbon-glass fiber hybrid composites and unidirectional carbon-glass fiber hybrid composites. The computational model results showed that woven fiber-reinforced composite materials were stiffer than the unidirectional fiber-reinforced composite materials. For instance, a forkbolt made of woven carbon fibers was 20% stiffer than a forkbolt made of unidirectional fibers symmetrically stacked in 0° and 90° alternating directions. Furthermore, Hybrid composite materials behaved as expected in forkbolt noticing a decline

  3. Stochastic resonance in bistable systems driven by harmonic noise

    International Nuclear Information System (INIS)

    Neiman, A.; Schimansky-Geier, L.

    1994-01-01

    We study stochastic resonance in a bistable system which is excited simultaneously by white and harmonic noise which we understand as the signal. In our case the spectral line of the signal has a finite width as it occurs in many real situations. Using techniques of cumulant analysis as well as computer simulations we find that the effect of stochastic resonance is preserved in the case of harmonic noise excitation. Moreover we show that the width of the spectral line of the signal at the output can be decreased via stochastic resonance. The last could be of importance in the practical using of the stochastic resonance

  4. Bistability By Self-Reflection In A Saturable Absorber

    Science.gov (United States)

    Roso-Franco, Luis

    1987-01-01

    Propagation of laser light through a saturable absorber is theoretically studied. Computed steady state solutions of the Maxwell equations describing the unidimensional propagation of a plane monochromatic wave without introducing the slowly-varying envelope approximation are presented showing how saturation effects can influence the absorption of the field. At a certain range of refractive index and extintion coefficients, computed solutions display a very susprising behaviour, and a self-reflected wave appears inside the absorber. This can be useful for a new kind of biestable device, similar to a standard bistable cavity but with the back mirror self-induced by the light.

  5. The tunable bistable and multistable memory effect in polymer nanowires

    International Nuclear Information System (INIS)

    Rahman, Atikur; Sanyal, Milan K

    2008-01-01

    Tunable bistable and multistable resistance switching in conducting polymer nanowires has been reported. These wires show reproducible switching transition under several READ-WRITE-ERASE cycles. The switching is observed at low temperature and the ON/OFF resistance ratio for the voltage biased switching transition was found to be more than 10 3 . Current biased measurements show lower ON/OFF ratio and some of the nanowires exhibit a multistable switching transition in current biased measurements. The threshold voltage for switching and the ON/OFF resistance ratio can be tuned by changing doping concentration of the nanowires

  6. Electron transfer dynamics of bistable single-molecule junctions

    DEFF Research Database (Denmark)

    Danilov, A.V; Kubatkin, S.; Kafanov, S. G.

    2006-01-01

    We present transport measurements of single-molecule junctions bridged by a molecule with three benzene rings connected by two double bonds and with thiol end-groups that allow chemical binding to gold electrodes. The I-V curves show switching behavior between two distinct states. By statistical ...... analysis of the switching events, we show that a 300 meV mode mediates the transition between the two states. We propose that breaking and reformation of a S-H bond in the contact zone between molecule and electrode explains the observed bistability....

  7. Application of the Asymptotic Taylor Expansion Method to Bistable Potentials

    Directory of Open Access Journals (Sweden)

    Okan Ozer

    2013-01-01

    Full Text Available A recent method called asymptotic Taylor expansion (ATEM is applied to determine the analytical expression for eigenfunctions and numerical results for eigenvalues of the Schrödinger equation for the bistable potentials. Optimal truncation of the Taylor series gives a best possible analytical expression for eigenfunctions and numerical results for eigenvalues. It is shown that the results are obtained by a simple algorithm constructed for a computer system using symbolic or numerical calculation. It is observed that ATEM produces excellent results consistent with the existing literature.

  8. Atom-loss-induced quantum optical bi-stability switch

    International Nuclear Information System (INIS)

    Wu Bao-Jun; Cui Fu-Cheng

    2012-01-01

    We investigate the nonlinear dynamics of a system composed of a cigar-shaped Bose—Einstein condensate and an optical cavity with the two sides coupled dispersively. By adopting discrete-mode approximation for the condensate, taking atom loss as a necessary part of the model to analyze the evolution of the system, while using trial and error method to find out steady states of the system as a reference, numerical simulation demonstrates that with a constant pump, atom loss will trigger a quantum optical bi-stability switch, which predicts a new interesting phenomenon for experiments to verify

  9. Optical bistabilities of higher harmonics: Inhomogeneous and transverse effects

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, S.S., E-mail: Shoukryhassan@hotmail.com [Department of Mathematics, College of Science, University of Bahrain, P.O. Box 32038 (Bahrain); Manchester Metropolitan University, Dept. of Computing, Maths. and Digital Technology, Manchester M1 5GD (United Kingdom); Sharaby, Y.A., E-mail: Yasser_Sharaby@hotmail.com [Department of Physics, Faculty of Science, Suez Canal University, Suez (Egypt); Ali, M.F.M., E-mail: dr.mona.fathy@hotmail.com [Department of Mathematics: Faculty of Science, Ain Shams University, Cairo (Egypt); Joshi, A., E-mail: ajoshi@eiu.edu [Department of Physics, Eastern Illinois University, Charleston, IL 61920 (United States)

    2012-10-15

    The steady state behavior of optical bistable system in a ring cavity with transverse field variations and inhomogeneousely broadened two-level atoms is investigated outside the rotating wave approximation (RWA). Analytical and numerical investigation is presented for different cases of transverse field variations with Lorentzian or Gaussian line widths. When both (transverse and inhomogeneous) features taken into account, the first harmonic output field component outside the RWA exhibits a one-way switching down processes (butterfly OB) or reversed (clockwise) OB behavior, depending on the atomic linewidth shape.

  10. Optical bistabilities of higher harmonics: Inhomogeneous and transverse effects

    International Nuclear Information System (INIS)

    Hassan, S.S.; Sharaby, Y.A.; Ali, M.F.M.; Joshi, A.

    2012-01-01

    The steady state behavior of optical bistable system in a ring cavity with transverse field variations and inhomogeneousely broadened two-level atoms is investigated outside the rotating wave approximation (RWA). Analytical and numerical investigation is presented for different cases of transverse field variations with Lorentzian or Gaussian line widths. When both (transverse and inhomogeneous) features taken into account, the first harmonic output field component outside the RWA exhibits a one-way switching down processes (butterfly OB) or reversed (clockwise) OB behavior, depending on the atomic linewidth shape.

  11. Bistable Helmholtz solitons in cubic-quintic materials

    International Nuclear Information System (INIS)

    Christian, J. M.; McDonald, G. S.; Chamorro-Posada, P.

    2007-01-01

    We propose a nonlinear Helmholtz equation for modeling the evolution of broad optical beams in media with a cubic-quintic intensity-dependent refractive index. This type of nonlinearity is appropriate for some semiconductor materials, glasses, and polymers. Exact analytical soliton solutions are presented that describe self-trapped nonparaxial beams propagating at any angle with respect to the reference direction. These spatially symmetric solutions are, to the best of our knowledge, the first bistable Helmholtz solitons to be derived. Accompanying conservation laws (both integral and particular forms) are also reported. Numerical simulations investigate the stability of the solitons, which appear to be remarkably robust against perturbations

  12. Bistable switching in dual-frequency liquid crystals

    Energy Technology Data Exchange (ETDEWEB)

    Palto, S. P., E-mail: palto@online.ru; Barnik, M I [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2006-06-15

    Various bistable switching modes in nematic liquid crystals with frequency inversion of the sign of dielectric anisotropy are revealed and investigated. Switching between states with different helicoidal distributions of the director field of a liquid crystal, as well as between uniform and helicoidal states, is realized by dual-frequency waveforms of a driving voltage. A distinctive feature of the dual-frequency switching is that the uniform planar distribution of the director field may correspond to a thermodynamically equilibrium state, and the chirality of an LC is not a necessary condition for switching to a helicoidal state.

  13. Entire solutions for bistable lattice differential equations with obstacles

    CERN Document Server

    Hoffman, Aaron; Vleck, E S Van

    2018-01-01

    The authors consider scalar lattice differential equations posed on square lattices in two space dimensions. Under certain natural conditions they show that wave-like solutions exist when obstacles (characterized by "holes") are present in the lattice. Their work generalizes to the discrete spatial setting the results obtained in Berestycki, Hamel, and Matuno (2009) for the propagation of waves around obstacles in continuous spatial domains. The analysis hinges upon the development of sub and super-solutions for a class of discrete bistable reaction-diffusion problems and on a generalization of a classical result due to Aronson and Weinberger that concerns the spreading of localized disturbances.

  14. Noticeable positive Doppler effect on optical bistability in an N-type active Raman gain atomic system

    International Nuclear Information System (INIS)

    Chang Zeng-Guang; Zhang Jing-Tao; Niu Yue-Ping; Gong Shang-Qing

    2012-01-01

    We theoretically investigate the Doppler effect on optical bistability in an N-type active Raman gain atomic system inside an optical ring cavity. It is shown that the Doppler effect can greatly enhance the dispersion and thus create the bistable behaviour or greatly increase the bistable region, which has been known as the positive Doppler effect on optical bistability. In addition, we find that a positive Doppler effect can change optical bistability from the hybrid dispersion-gain type to a dispersive type

  15. Derivation of magnetic Coulomb's law for thin, semi-infinite solenoids

    OpenAIRE

    Kitano, Masao

    2006-01-01

    It is shown that the magnetic force between thin, semi-infinite solenoids obeys a Coulomb-type law, which corresponds to that for magnetic monopoles placed at the end points of each solenoid. We derive the magnetic Coulomb law from the basic principles of electromagnetism, namely from the Maxwell equations and the Lorentz force.

  16. Plasma heating in a long solenoid by a laser or a relativistic electron beam

    International Nuclear Information System (INIS)

    Tajima, T.

    1975-01-01

    Advances in the technology of a large energy laser and/or relativistic electron beam (REB) generator have made it possible to seriously consider a long solenoid reactor concept. This concept has been reviewed. The physical problems in the plasma heating of the long solenoid by a laser or a REB are studied

  17. A large superconducting thin solenoid for the STAR experiment at RHIC

    International Nuclear Information System (INIS)

    Green, M.A.

    1992-06-01

    This Report describes the 4.4 meter, warm bore diameter, thin superconducting solenoid, for the proposed STAR experiment at the Brookhaven National Laboratory. The STAR solenoid will generate a very uniform central magnetic induction of 0.5 T within a space which is 4.0 meters in diameter by 4.2 meters long. The solenoid and its cryostat will be 0.7 radiation lengths thick over a length of 5.45 meters, about the center of the magnet making it the largest solenoid less than one radiation length to be built. This report describes a proposed design for the solenoid and cryostat, its flux return iron, its cryogenic system and its power supply and quench protection system

  18. Performance of a proximity cryogenic system for the ATLAS central solenoid magnet

    CERN Document Server

    Doi, Y; Makida, Y; Kondo, Y; Kawai, M; Aoki, K; Haruyama, T; Kondo, T; Mizumaki, S; Wachi, Y; Mine, S; Haug, F; Delruelle, N; Passardi, Giorgio; ten Kate, H H J

    2002-01-01

    The ATLAS central solenoid magnet has been designed and constructed as a collaborative work between KEK and CERN for the ATLAS experiment in the LHC project The solenoid provides an axial magnetic field of 2 Tesla at the center of the tracking volume of the ATLAS detector. The solenoid is installed in a common cryostat of a liquid-argon calorimeter in order to minimize the mass of the cryostat wall. The coil is cooled indirectly by using two-phase helium flow in a pair of serpentine cooling line. The cryogen is supplied by the ATLAS cryogenic plant, which also supplies helium to the Toroid magnet systems. The proximity cryogenic system for the solenoid has two major components: a control dewar and a valve unit In addition, a programmable logic controller, PLC, was prepared for the automatic operation and solenoid test in Japan. This paper describes the design of the proximity cryogenic system and results of the performance test. (7 refs).

  19. Detector solenoid compensation in the PEP-II B-Factory

    International Nuclear Information System (INIS)

    Nosochkov, Y.; Cai, Y.; Irwin, J.; Sullivan, M.

    1995-01-01

    The PEP-II experimental detector includes a strong 1.5 T solenoid field in the interaction region (IR). With the fringe fields, the solenoid extends over a range of 6 m. Additional complications are that (1) it is displaced longitudinally from the interaction point (IP) by about 40 cm, (2) neither beam is parallel to the solenoid axis, and (3) the solenoid overlaps a dipole and a quadrupole on either side of the IP. In each half IR the correction system includes a set of skew quadrupoles, dipole correctors and normal quadrupoles to independently compensate the coupling, orbit perturbation, dispersion and focusing effect produced by the solenoid. The correction schemes for the Low Energy Ring (LER) and for the High Energy Ring (HER) are described, and the impact on the dynamic aperture is evaluated

  20. Multiple Bistability in Quinonoid-Bridged Diiron(II) Complexes: Influence of Bridge Symmetry on Bistable Properties.

    Science.gov (United States)

    van der Meer, Margarethe; Rechkemmer, Yvonne; Breitgoff, Frauke D; Marx, Raphael; Neugebauer, Petr; Frank, Uta; van Slageren, Joris; Sarkar, Biprajit

    2016-11-21

    Quinonoid bridges are well-suited for generating dinuclear assemblies that might display various bistable properties. In this contribution we present two diiron(II) complexes where the iron(II) centers are either bridged by the doubly deprotonated form of a symmetrically substituted quinonoid bridge, 2,5-bis[4-(isopropyl)anilino]-1,4-benzoquinone (H 2 L2') with a [O,N,O,N] donor set, or with the doubly deprotonated form of an unsymmetrically substituted quinonoid bridge, 2-[4-(isopropyl)anilino]-5-hydroxy-1,4-benzoquinone (H 2 L5') with a [O,O,O,N] donor set. Both complexes display temperature-induced spin crossover (SCO). The nature of the SCO is strongly dependent on the bridging ligand, with only the complex with the [O,O,O,N] donor set displaying a prominent hysteresis loop of about 55 K. Importantly, only the latter complex also shows a pronounced light-induced spin state change. Furthermore, both complexes can be oxidized to the mixed-valent iron(II)-iron(III) form, and the nature of the bridge determines the Robin and Day classification of these forms. Both complexes have been probed by a battery of electrochemical, spectroscopic, and magnetic methods, and this combined approach is used to shed light on the electronic structures of the complexes and on bistability. The results presented here thus show the potential of using the relatively new class of unsymmetrically substituted bridging quinonoid ligands for generating intriguing bistable properties and for performing site-specific magnetic switching.

  1. High-voltage Pulse-triggered SR Latch Level-Shifter Design Considerations

    DEFF Research Database (Denmark)

    Larsen, Dennis Øland; Llimos Muntal, Pere; Jørgensen, Ivan Harald Holger

    2014-01-01

    translating a signal from 0- 3 : 3 V to 87 : 5 - 100 V. The operation of this level-shifter is verified with measurements on a fabricated chip. The shortcomings of the implemented level-shifter in terms of power dissipation, transition delay, area, and startup behavior are then considered and an improved......This paper compares pulse-triggered level shifters with a traditional level-triggered topology for high-voltage ap- plications with supply voltages in the 50 V to 100 V range. It is found that the pulse-triggered SR (Set/Reset) latch level- shifter has a superior power consumption of 1800 W = MHz...... circuit is suggested which has been designed in three variants being able to translate the low-voltage 0- 3 : 3 V signal to 45 - 50 V, 85 - 90 V, and 95 - 100 V respectively. The improved 95 - 100 V level shifter achieves a considerably lower power consumption of 438 W = MHz along with a significantly...

  2. Understanding Graphics on a Scalable Latching Assistive Haptic Display Using a Shape Memory Polymer Membrane.

    Science.gov (United States)

    Besse, Nadine; Rosset, Samuel; Zarate, Juan Jose; Ferrari, Elisabetta; Brayda, Luca; Shea, Herbert

    2018-01-01

    We present a fully latching and scalable 4 × 4 haptic display with 4 mm pitch, 5 s refresh time, 400 mN holding force, and 650 μm displacement per taxel. The display serves to convey dynamic graphical information to blind and visually impaired users. Combining significant holding force with high taxel density and large amplitude motion in a very compact overall form factor was made possible by exploiting the reversible, fast, hundred-fold change in the stiffness of a thin shape memory polymer (SMP) membrane when heated above its glass transition temperature. Local heating is produced using an addressable array of 3 mm in diameter stretchable microheaters patterned on the SMP. Each taxel is selectively and independently actuated by synchronizing the local Joule heating with a single pressure supply. Switching off the heating locks each taxel into its position (up or down), enabling holding any array configuration with zero power consumption. A 3D-printed pin array is mounted over the SMP membrane, providing the user with a smooth and room temperature array of movable pins to explore by touch. Perception tests were carried out with 24 blind users resulting in 70 percent correct pattern recognition over a 12-word tactile dictionary.

  3. Polarization encoded all-optical quaternary R-S flip-flop using binary latch

    Science.gov (United States)

    Chattopadhyay, Tanay; Roy, Jitendra Nath; Chakraborty, Ajoy Kumar

    2009-04-01

    The developments of different multi-valued logic (MVL) systems have received considerable interests in recent years all over the world. In electronics, efforts have already been made to incorporate multi-valued system in logic and arithmetic data processing. But, very little efforts have been given in realization of MVL with optics. In this paper we present novel designs of certain all-optical circuits that can be used for realizing multi-valued logic functions. Polarization encoded all-optical quaternary (4-valued) R-S flip-flop is proposed and described. Two key circuits (all-optical encoder/decoder and a binary latch) are designed first. They are used to realize quaternary flip-flop in all-optical domain. Here the different quaternary logical states are represented by different polarized state of light. Terahertz Optical Asymmetric Demultiplexer (TOAD) based interferometric switch can take an important role. Computer simulation result confirming described methods and conclusion are given in this paper.

  4. SEU simulation and testing of resistor-hardened D-latches in the SA3300 microprocessor

    International Nuclear Information System (INIS)

    Sexton, F.W.; Corbett, W.T.; Treece, R.K.; Hass, K.J.; Axness, C.L.; Hash, G.L.; Shaneyfelt, M.R.; Wunsch, T.F.; Hughes, K.L.

    1991-01-01

    In this paper the SEU tolerance of the SA3300 microprocessor with feedback resistors is presented and compared to the SA3300 without feedback resistors and to the commercial version (NS32016). Upset threshold at room temperature increased from 23 MeV-cm 2 /mg and 180 MeV-cm 2 /mg with feedback resistors of 50 kΩ and 160 kΩ, respectively. The performance goal of 10 MHz over the full temperature range of -55 degrees C to +125 degrees C is exceeded for feedback resistors of 160 kΩ and less. Error rate calculations for this design predict that the error rate is less than once every 100 years when 50 kΩ feedback resistors are used in the D-latch design. Analysis of the SEU response using a lumped-parameter circuit simulator imply a charge collection depth of 4.5 μm. This is much deeper than the authors would expect for prompt collection in the epi and funnel regions and has been explained in terms of diffusion current in the heavily doped substrate

  5. Optical bistability and limiting in polymer dispersed liquid crystal

    Energy Technology Data Exchange (ETDEWEB)

    Yshino, K.; Tagawa, A.; Sadohara, Y.; Ozaki, M. (Osaka University, Osaka (Japan). Faculty of Engineering); Munezawa, T. (Ajinomoto Co. Inc., Tokyo (Japan)); Nomura, Y. (Takiron Co. Ltd., Osaka (Japan))

    1991-04-15

    The linear electro-optical effect of polymer dispersed liquid crystal (PDLC) and the nonlinear optical response of electrically feedbacked PDLC were studied. Electro-optical limiting and bistability were observed in PDLCs with negative and positive feedback, respectively. In the PDLC film with positive feedback gain, an optical hysteresis loop shifted toward a high intensity region with decreasing magnitude of the feedback gain. The switching between high and low transmission states in an optical bistable region was realized by controlling incident light, and the on-off switching by superimposing light pulse on incident light for an extremely short period (several hundreds {mu}s). As the light pulse was strong, the minimum pulse width required for switching was as short as 500 {mu}s or less. The on-off switching was also realized by shutting out the incident light for a period equivalent to the pulse width. Slower response times of the PDLC film required longer minimum pulse widths. 12 refs., 11 figs.

  6. Bistability and displacement fluctuations in a quantum nanomechanical oscillator

    Science.gov (United States)

    Avriller, R.; Murr, B.; Pistolesi, F.

    2018-04-01

    Remarkable features have been predicted for the mechanical fluctuations at the bistability transition of a classical oscillator coupled capacitively to a quantum dot [Micchi et al., Phys. Rev. Lett. 115, 206802 (2015), 10.1103/PhysRevLett.115.206802]. These results have been obtained in the regime ℏ ω0≪kBT ≪ℏ Γ , where ω0, T , and Γ are the mechanical resonating frequency, the temperature, and the tunneling rate, respectively. A similar behavior could be expected in the quantum regime of ℏ Γ ≪kBT ≪ℏ ω0 . We thus calculate the energy- and displacement-fluctuation spectra and study their behavior as a function of the electromechanical coupling constant when the system enters the Frank-Condon regime. We find that in analogy with the classical case, the energy-fluctuation spectrum and the displacement spectrum widths show a maximum for values of the coupling constant at which a mechanical bistability is established.

  7. Designing a stochastic genetic switch by coupling chaos and bistability

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xiang [State Key Laboratory for Mesoscopic Physics and School of Physics, Peking University, Beijing 100871 (China); Ouyang, Qi [State Key Laboratory for Mesoscopic Physics and School of Physics, Peking University, Beijing 100871 (China); Center for Quantitative Biology, Peking University, Beijing 100871 (China); The Peking-Tsinghua Center for Life Sciences, Beijing 100871 (China); Wang, Hongli, E-mail: hlwang@pku.edu.cn [State Key Laboratory for Mesoscopic Physics and School of Physics, Peking University, Beijing 100871 (China); Center for Quantitative Biology, Peking University, Beijing 100871 (China)

    2015-11-15

    In stem cell differentiation, a pluripotent stem cell becomes progressively specialized and generates specific cell types through a series of epigenetic processes. How cells can precisely determine their fate in a fluctuating environment is a currently unsolved problem. In this paper, we suggest an abstract gene regulatory network to describe mathematically the differentiation phenomenon featuring stochasticity, divergent cell fates, and robustness. The network consists of three functional motifs: an upstream chaotic motif, a buffering motif of incoherent feed forward loop capable of generating a pulse, and a downstream motif which is bistable. The dynamic behavior is typically a transient chaos with fractal basin boundaries. The trajectories take transiently chaotic journeys before divergently settling down to the bistable states. The ratio of the probability that the high state is achieved to the probability that the low state is reached can maintain a constant in a population of cells with varied molecular fluctuations. The ratio can be turned up or down when proper parameters are adjusted. The model suggests a possible mechanism for the robustness against fluctuations that is prominently featured in pluripotent cell differentiations and developmental phenomena.

  8. Control and characterization of a bistable laminate generated with piezoelectricity

    Science.gov (United States)

    Lee, Andrew J.; Moosavian, Amin; Inman, Daniel J.

    2017-08-01

    Extensive research has been conducted on utilizing smart materials such as piezoelectric and shape memory alloy actuators to induce snap through of bistable structures for morphing applications. However, there has only been limited success in initiating snap through from both stable states due to the lack of actuation authority. A novel solution in the form of a piezoelectrically generated bistable laminate consisting of only macro fiber composites (MFC), allowing complete configuration control without any external assistance, is explored in detail here. Specifically, this paper presents the full analytical, computational, and experimental results of the laminate’s design, geometry, bifurcation behavior, and snap through capability. By bonding two actuated MFCs in a [0MFC/90MFC]T layup and releasing the voltage post cure, piezoelectric strain anisotropy and the resulting in-plane residual stresses yield two statically stable states that are cylindrically shaped. The analytical model uses the Rayleigh-Ritz minimization of total potential energy and finite element analysis is implemented in MSC Nastran. The [0MFC/90MFC]T laminate is then manufactured and experimentally characterized for model validation. This paper demonstrates the adaptive laminate’s unassisted forward and reverse snap through capability enabled by the efficiencies gained from simultaneously being the actuator and the primary structure.

  9. A new concept for active bistable twisting structures

    Science.gov (United States)

    Schultz, Marc R.

    2005-05-01

    A novel type of morphing structure capable of a large change in shape with a small energy input is discussed in this paper. The considered structures consist of two curved shells that are joined in a specific manner to form a bistable airfoil-like structure. The two stable shapes have a difference in axial twist, and the structure may be transformed between the stable shapes by a simple snap-through action. The benefit of a bistable structure of this type is that, if the stable shapes are operational shapes, power is needed only to transform the structure from one shape to another. The discussed structures could be used in aerodynamic applications such as morphing wings, or as aerodynamic control surfaces. The investigation discussed in this paper considers both experiment and finite-element analysis. Several graphite-epoxy composite and one steel device were created as proof-of-concept models. To demonstrate active control of these structures, piezocomposite actuators were applied to one of the composite structures and used to transform the structure between stable shapes. The analysis was used to compare the predicted shapes with the experimental shapes, and to study how changes to the geometric input values affected the shape and operational characteristics of the structures. The predicted shapes showed excellent agreement with the experimental shapes, and the results of the parametric study suggest that the shapes and the snap-through characteristics can be easily tailored to meet specific needs.

  10. A Reliable Bistable Board Implementation through I/O Redundancy

    International Nuclear Information System (INIS)

    Kim, Min Gyu; Chung, Tae Hyok; Lee, Youn Sang; Kim, Tae Hee; Song, Seung Hwan

    2010-01-01

    Nuclear power plant safety systems and related equipment used in the design, including an accident in all driving conditions that must be proven In addition, the safety-related equipment that is derived according to the digitization of the safety equipment is the most important factors. Therefore, it is necessary to prove that the device was satisfied the requirements for a given performance for safety-related digital equipment for the life of the installation. These proven is done through the process, design verification of the equipment, production management, such as installation and maintenance. Among other things, it is most important to implement of the performance and reliability features the safety-related equipment in the design phase. In this paper, Bistable Board implemented to generate a ESF sign-on signal throughout the signal processing of input signal from sensors. Also, for the reliable signal input and output, I/O Module that implements the redundancy increases the reliability of the Bistable Board , to verify the performance of safety-related equipment

  11. Designing a stochastic genetic switch by coupling chaos and bistability.

    Science.gov (United States)

    Zhao, Xiang; Ouyang, Qi; Wang, Hongli

    2015-11-01

    In stem cell differentiation, a pluripotent stem cell becomes progressively specialized and generates specific cell types through a series of epigenetic processes. How cells can precisely determine their fate in a fluctuating environment is a currently unsolved problem. In this paper, we suggest an abstract gene regulatory network to describe mathematically the differentiation phenomenon featuring stochasticity, divergent cell fates, and robustness. The network consists of three functional motifs: an upstream chaotic motif, a buffering motif of incoherent feed forward loop capable of generating a pulse, and a downstream motif which is bistable. The dynamic behavior is typically a transient chaos with fractal basin boundaries. The trajectories take transiently chaotic journeys before divergently settling down to the bistable states. The ratio of the probability that the high state is achieved to the probability that the low state is reached can maintain a constant in a population of cells with varied molecular fluctuations. The ratio can be turned up or down when proper parameters are adjusted. The model suggests a possible mechanism for the robustness against fluctuations that is prominently featured in pluripotent cell differentiations and developmental phenomena.

  12. Model-based design of bistable cell factories for metabolic engineering.

    Science.gov (United States)

    Srinivasan, Shyam; Cluett, William R; Mahadevan, Radhakrishnan

    2018-04-15

    Metabolism can exhibit dynamic phenomena like bistability due to the presence of regulatory motifs like the positive feedback loop. As cell factories, microorganisms with bistable metabolism can have a high and a low product flux at the two stable steady states, respectively. The exclusion of metabolic regulation and network dynamics limits the ability of pseudo-steady state stoichiometric models to detect the presence of bistability, and reliably assess the outcomes of design perturbations to metabolic networks. Using kinetic models of metabolism, we assess the change in the bistable characteristics of the network, and suggest designs based on perturbations to the positive feedback loop to enable the network to produce at its theoretical maximum rate. We show that the most optimal production design in parameter space, for a small bistable metabolic network, may exist at the boundary of the bistable region separating it from the monostable region of low product fluxes. The results of our analysis can be broadly applied to other bistable metabolic networks with similar positive feedback network topologies. This can complement existing model-based design strategies by providing a smaller number of feasible designs that need to be tested in vivo. http://lmse.biozone.utoronto.ca/downloads/. krishna.mahadevan@utoronto.ca. Supplementary data are available at Bioinformatics online.

  13. Performance of Nb3Sn multifilamentary superconductors in solenoidal magnets

    International Nuclear Information System (INIS)

    Sampson, W.B.; Suenaga, M.; Robins, K.E.

    High current Nb 3 Sn multifilamentary conductors have been formed by heat treating cables braided from three types of composite wire. In the simplest configuration, these wires contain niobium filaments in a pure copper matrix. After braiding the conductor is coated with a layer of tin which diffuses through the copper during heat treatment to form Nb 3 S n filaments. The second configuration is made from wires containing niobium filaments in a copper-tin alloy and requires only heat treatment to form the Nb 3 Sn filaments. The third type of braid has wires which consist of groups of niobium filaments in the bronze matrix which are in turn in a copper matrix. Tantalum barriers surround each group of filaments to prevent the tin from contaminating the pure copper matrix. The cables have been wound into solenoids after heat treatment and the effect of mechanical handling was studied by monitoring the resistive voltage distribution in the coils. (U.S.)

  14. submitter Starting Manufacture of the ITER Central Solenoid

    CERN Document Server

    Libeyre, P; Dolgetta, N; Gaxiola, E; Jong, C; Lyraud, C; Mitchell, N; Journeaux, J Y; Vollmann, T; Evans, D; Sgobba, S; Langeslag, S; Reiersen, W; Martovetsky, N; Everitt, D; Hatfield, D; Rosenblad, P; Litherland, S; Freudenberg, K; Myatt, L; Smith, J; Brazelton, C; Abbott, R; Daubert, J; Rackers, K; Nentwich, T

    2016-01-01

    The central solenoid (CS) is a key component of the ITER magnet system to provide the magnetic flux swing required to drive induced plasma current up to 15 MA. The manufacture of its different subcomponents has now started, following completion of the design analyses and achievement of the qualification of the manufacturing procedures. A comprehensive set of analyses has been produced to demonstrate that the CS final design meets all requirements. This includes in particular structural analyses carried out with different finite-element models and addressing normal and fault conditions. Following the Final Design Review, held in November 2013, and the subsequent design modifications, the analyses were updated for consistency with the final design details and provide evidence that the Magnet Structural Design Criteria are fully met. Before starting any manufacturing activity of a CS component, a corresponding dedicated qualification program has been carried out. This includes manufacture of mockups using the re...

  15. Quench protection analysis of the Mu2e production solenoid

    International Nuclear Information System (INIS)

    Kashikhin, Vadim; Ambrosio, Giorgio; Andreev, Nikolai; Lamm, Michael; Nicol, Thomas; Orris, Darryl; Page, Thomas

    2014-01-01

    The Muon-to-Electron conversion experiment (Mu2e), under development at Fermilab, seeks to detect direct muon to electron conversion to provide evidence for a process violating muon and electron lepton number conservation that cannot be explained by the Standard Model of particle physics. The Mu2e magnet system consists of three large superconducting solenoids. In case of a quench, the stored magnetic energy is extracted to an external dump circuit. However, because of the fast current decay, a significant fraction of the energy dissipates inside of the cryostat in the coil support shells made of structural aluminum, and in the radiation shield. A 3D finite-element model of the complete cold-mass was created in order to simulate the quench development and understand the role of the quench-back. The simulation results are reported at the normal and non-standard operating conditions

  16. Quench protection analysis of the Mu2e production solenoid

    Science.gov (United States)

    Kashikhin, Vadim; Ambrosio, Giorgio; Andreev, Nikolai; Lamm, Michael; Nicol, Thomas; Orris, Darryl; Page, Thomas

    2014-01-01

    The Muon-to-Electron conversion experiment (Mu2e), under development at Fermilab, seeks to detect direct muon to electron conversion to provide evidence for a process violating muon and electron lepton number conservation that cannot be explained by the Standard Model of particle physics. The Mu2e magnet system consists of three large superconducting solenoids. In case of a quench, the stored magnetic energy is extracted to an external dump circuit. However, because of the fast current decay, a significant fraction of the energy dissipates inside of the cryostat in the coil support shells made of structural aluminum, and in the radiation shield. A 3D finite-element model of the complete cold-mass was created in order to simulate the quench development and understand the role of the quench-back. The simulation results are reported at the normal and non-standard operating conditions.

  17. Testing of the superconducting solenoid for the Fermilab collider detector

    International Nuclear Information System (INIS)

    Fast, R.W.; Holmes, C.N.; Kephart, R.D.

    1985-07-01

    The 3 m phi x 5 m long x 1.5 T superconducting solenoid for the Fermilab Collider Detector has been installed at Fermilab and was tested in early 1985 with a dedicated refrigeration system. The refrigerator and 5.6-Mg magnet cold mass were cooled to 5 K in 210 hours. After testing at low currents, the magnet was charged to the design current of 5 kA in 5-MJ steps. During a 390 A/min charge a spontaneous quench occurred at 4.5 kA due to insufficient liquid helium flow. Three other quenches occurred during ''slow'' discharges which were nevertheless fast enough to cause high eddy current heating in the outer support cylinder. Quench behavior is well understood and the magnet is now quite reliable

  18. Start-up of spherical tokamak without a center solenoid

    International Nuclear Information System (INIS)

    Maekawa, Takashi; Nagata, Masayoshi

    2012-01-01

    For low-aspect tokamak reactors, spherical tokamak reactors, ST-type FESF/CTFs, it is essential to remove or minimize a central solenoid (CS). Even with the minimized CS, non-inductive start up of the plasma current is required. Rapid increase in the spontaneous plasma current at the final stage of current start-up drives ignition. At the initial stage, formation of plasma and magnetic surfaces are required. As non-inductive plasma start-up scenarios, ECH/ECCD, LHCD, HHFW, DC HELICITY injection, plasma merging and NBI have been studied. In the present article, the present status and future prospect of experimental and theoretical works on these subjects. (author)

  19. Behaviour of large cylindrical drift chambers in a superconducting solenoid

    International Nuclear Information System (INIS)

    Boer, W. de; Fues, W.; Grindhammer, G.; Kotthaus, R.; Lierl, H.; Moss, L.

    1980-04-01

    We describe the construction and behaviour of a set of cylindrical drift chambers operating inside a superconducting solenoid with a central magnetic field of 1.3 T. The chambers are part of the 4 π detector CELLO at the e + e - storage ring PETRA in Hamburg. The chambers were designed without field shaping to keep them as simple as possible. In order to parametrize accurately the nonlinear space-time relation, we used a computer simulation of the drift process in inhomogenous electric and magnetic fields. With such a parametrization we achieved a resolution of 210 μm, averaged over the whole drift cell and angles of incidence up to 30 0 . (orig.)

  20. Design of the pancake-winding central solenoid coil

    International Nuclear Information System (INIS)

    Yoshida, Kiyoshi; Nishi, Masataka; Tsuji, Hirosi

    1995-01-01

    There was a debate over whether a pancake-winding or layer-winding technique is more appropriate for the Central Solenoid (CS) coil for ITER superconducting magnet. The layer-winding CS has the advantage of homogeneous winding supporting the TF centering force without weak joints, but has many difficulties during manufacturing and quality control. On other hand, the pancake-winding has the advantage of better quality control during manufacturing and module testing but has difficulties with joints and feeders, and pipes located in the load path of the bucking force from the toroidal field coils. The compact joints, reinforcement by preformed amour, sharp bending, and double seals are applied to the design of pancake-winding CS coil and demonstrated by hardware developments. The pancake-winding CS coil by using modified existing technology is compatible with the bucking concept of the ITER magnet system. (author)

  1. Conceptual fusion reactor designs based on the laser heat solenoid

    International Nuclear Information System (INIS)

    Steinhauer, L.C.

    1976-01-01

    The feasibility of the laser heated solenoid (LHS) as an approach to fusion and fusion-fission commercial power generation has been examined. The LHS concept is based on magnetic confinement of a long slender plasma column which is partly heated by the axially directed beam from a powerful long wavelength laser. As a pure fusion concept, the LHS configurations studied so far are characterized by fairly difficult engineering constraints, particularly on the magnet, a large laser, and a marginally acceptable system energy balance. As a fusion-fission system, however, the LHS is capable of a very attractive energy balance, has much more relaxed engineering constraints, requires a relatively modest laser, and as such holds great potential as a power generator and fissile fuel breeding scheme

  2. Fusion--fission hybrid reactors based on the laser solenoid

    International Nuclear Information System (INIS)

    Steinhauer, L.C.; Taussig, R.T.; Quimby, D.C.

    1976-01-01

    Fusion-fission reactors, based on the laser solenoid concept, can be much smaller in scale than their pure fusion counterparts, with moderate first-wall loading and rapid breeding capabilities (1 to 3 tonnes/yr), and can be designed successfully on the basis of classical plasma transport properties and free-streaming end-loss. Preliminary design information is presented for such systems, including the first wall, pulse coil, blanket, superconductors, laser optics, and power supplies, accounting for the desired reactor performance and other physics and engineering constraints. Self-consistent point designs for first and second generation reactors are discussed which illustrate the reactor size, performance, component parameters, and the level of technological development required

  3. Alternative connections for the large MFTF-B solenoids

    International Nuclear Information System (INIS)

    Owen, E.W.; Shimer, D.W.; Wang, S.T.

    1983-01-01

    The MFTF-B central-cell solenoids are a set of twelve closely coupled, large superconducting magnets with similar but not exactly equal currents. Alternative methods of connecting them to their power supplies and dump resistors are investigated. The circuits are evaluated for operating conditions and fault conditions. The factors considered are the voltage to ground during a dump, short circuits, open circuits, quenches, and failure of the protection system to detect a quench. Of particular interest are the current induced in coils that remain superconducting when one or more coils quench. The alternative connections include separate power supplies, combined power supplies, individual dump resistors, series dump resistors and combinations of these. A new circuit that contains coupling resistors is proposed. The coupling resistors do not affect normal fast dumps but reduce the peak induced currents while also reducing the energy rating of the dump resistors. Another novel circuit, the series circuit with diodes, is discussed in detail

  4. Construction of compact FEM using solenoid-induced helical wiggler

    International Nuclear Information System (INIS)

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

    2003-01-01

    A prototype of compact Free-Electron Maser (FEM) has been designed for the operation in a usual small laboratory which does not have electric source capacity available enough. The electron energy is 60-120 keV. As it is lower, stronger guiding magnetic field is necessary in addition to wiggler field. To fulfil this condition a solenoid-induced helical wiggler is applied from the viewpoint of saving the electric power of restricted source capacity. The wiggler, for example, with the period of 12 mm creates the field of 92 G in the guiding field of 3.2 kG. The whole system of FEM has been just constructed in a small-scale laboratory. It is so small to occupy the area of 0.7x2.9 m 2

  5. Numerical analysis of modified Central Solenoid insert design

    Energy Technology Data Exchange (ETDEWEB)

    Khodak, Andrei, E-mail: akhodak@pppl.gov [Princeton Plasma Physics Laboratory, Princeton, NJ (United States); Martovetsky, Nicolai; Smirnov, Aleksandre [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Titus, Peter [Princeton Plasma Physics Laboratory, Princeton, NJ (United States)

    2015-10-15

    Highlights: • Modified design of coil for testing ITER superconducting cable is presented. • Numerical analysis allowed design verification. • Three-dimensional current sharing temperature distributions are obtained from the results. - Abstract: The United States ITER Project Office (USIPO) is responsible for fabrication of the Central Solenoid (CS) for ITER project. The ITER machine is currently under construction by seven parties in Cadarache, France. The CS Insert (CSI) project should provide a verification of the conductor performance in relevant conditions of temperature, field, currents and mechanical strain. The US IPO designed the CSI that will be tested at the Central Solenoid Model Coil (CSMC) Test Facility at JAEA, Naka. To validate the modified design three-dimensional numerical simulations were performed using coupled solver for simultaneous structural, thermal and electromagnetic analysis. Thermal and electromagnetic simulations supported structural calculations providing necessary loads and strains. According to current analysis design of the modified coil satisfies ITER magnet structural design criteria for the following conditions: (1) room temperature, no current, (2) temperature 4 K, no current, (3) temperature 4 K, current 60 kA direct charge, and (4) temperature 4 K, current 60 kA reverse charge. Fatigue life assessment analysis is performed for the alternating conditions of: temperature 4 K, no current, and temperature 4 K, current 45 kA direct charge. Results of fatigue analysis show that parts of the coil assembly can be qualified for up to 1 million cycles. Distributions of the Current Sharing Temperature (TCS) in the superconductor were obtained from numerical results using parameterization of the critical surface in the form similar to that proposed for ITER. Special ADPL scripts were developed for ANSYS allowing one-dimensional representation of TCS along the cable, as well as three-dimensional fields of TCS in superconductor

  6. Bistable resistive memory behavior in gelatin-CdTe quantum dot composite film

    Science.gov (United States)

    Vallabhapurapu, Sreedevi; Rohom, Ashwini; Chaure, N. B.; Du, Shengzhi; Srinivasan, Ananthakrishnan

    2018-05-01

    Bistable memory behavior has been observed for the first time in gelatin type A thin film dispersed with functionalized CdTe quantum dots. The two terminal device with the polymer nanocomposite layer sandwiched between an indium tin oxide coated glass plate and an aluminium top electrode performs as a bistable resistive random access memory module. Butterfly shaped (O-shaped with a hysteresis in forward and reverse sweeps) current-voltage response is observed in this device. The conduction mechanism leading to the bistable electrical switching has been deduced to be a combination of ohmic and electron hopping.

  7. Bistability Analysis of Excitatory-Inhibitory Neural Networks in Limited-Sustained-Activity Regime

    International Nuclear Information System (INIS)

    Ni Yun; Wu Liang; Wu Dan; Zhu Shiqun

    2011-01-01

    Bistable behavior of neuronal complex networks is investigated in the limited-sustained-activity regime when the network is composed of excitatory and inhibitory neurons. The standard stability analysis is performed on the two metastable states separately. Both theoretical analysis and numerical simulations show consistently that the difference between time scales of excitatory and inhibitory populations can influence the dynamical behaviors of the neuronal networks dramatically, leading to the transition from bistable behaviors with memory effects to the collapse of bistable behaviors. These results may suggest one possible neuronal information processing by only tuning time scales. (interdisciplinary physics and related areas of science and technology)

  8. Optical nonlinearity and bistability in the bound exciton energy range of CdS

    International Nuclear Information System (INIS)

    Hoenig, T.; Gutowski, J.

    1988-01-01

    Under high excitation conditions thick CdS samples show pronounced broad-band nonlinear transmission in the bound exciton region and up to a wavelength of about 515 nm at cryo-temperatures. This behavior is only explainable in a model based on impurity neutralization and bound exciton creation. The suitability of these nonlinearities to yield optical bistability will be shown. Bistable operation is investigated in dependence of crystal thickness, impurity concentration, excitation density, wavelength, and temperature. A strong correlation to acceptor-bound exciton generation is obtained, and the explanation of this bistable operation fits well with that of the above mentioned transmission behavior. (author)

  9. Orbital parameters of proton and deuteron beams in the NICA collider with solenoid Siberian snakes

    International Nuclear Information System (INIS)

    Kovalenko, A D; Butenko, A V; Kekelidze, V D; Mikhaylov, V A; Kondratenko, M A; Filatov, Yu N; Kondratenko, A M

    2016-01-01

    Two solenoid Siberian snakes are required to obtain ion polarization in the “spin transparency” mode of the NICA collider. The field integrals of the solenoid snakes for protons and deuterons at maximum momentum of 13.5 GeV/c are equal to 2×50 T·m and 2×160 T·m respectively. The snakes introduce strong betatron oscillation coupling. The calculations of orbital parameters of proton and deuteron beams in NICA collider with solenoid snakes are presented. (paper)

  10. Spin Transparency Mode in the NICA Collider with Solenoid Siberian Snakes for Proton and Deuteron Beam

    Science.gov (United States)

    Kovalenko, A. D.; Butenko, A. V.; Mikhaylov, V. A.; Kondratenko, M. A.; Kondratenko, A. M.; Filatov, Yu N.

    2017-12-01

    Two solenoid Siberian Snakes are required to obtain ion polarization in spin transparency mode of the NICA collider. The snake solenoids with a total field integral of 2×50 T·m are placed into the straight sections of the NICA collider. It allows one to control polarization of protons and deuterons up to 13.5 GeV/c and 4 GeV/c respectively. The snakes introduce a strong betatron oscillation coupling. The calculations of orbital parameters of proton and deuteron beams in the NICA collider with solenoid Snakes are presented.

  11. Computer simulations of quench properties of thin, large superconducting solenoid magnets

    International Nuclear Information System (INIS)

    Kishimoto, Takeshi; Mori, Shigeki; Noguchi, Masaharu

    1983-01-01

    Measured quench data of a 1 m diameter x 1 m thin superconducting solenoid magnet with a single layer aluminum-stabilized NbTi/Cu superconductor of 269 turns were fitted by computer simulations using the one-dimensional approximation. Parameters obtained were used to study quench properties of a 3 m diameter x 5 m (1.5 Tesla) thin superconducting solenoid magnet with a stored magnetic energy of 30 x 10 6 J. Conductor dimensions with which the solenoid could be built substantially safe for the full field quench were optimized. (author)

  12. LIL-W: Positron conversion target and solenoid (pictures 01 and 04).

    CERN Multimedia

    Laurent Guiraud

    1997-01-01

    In the direction of the beam, from right to left: a steering dipole (DHZ.25); the arm, at 45 deg, of a wire scanner which measures beam size; the conversion target, housed in the small tank with a window, where positrons are produced; immediately afterwards, invisible inside the vacuum chamber, is a pulsed solenoid to focus the emerging positrons; finally, a large solenoid, consisting of 3 pancakes, further focuses the positrons. Towards the left, the linac LIL-W, its accelerating structure hidden under a continuous outer solenoid mantle.

  13. Delay induced stability switch, multitype bistability and chaos in an intraguild predation model.

    Science.gov (United States)

    Shu, Hongying; Hu, Xi; Wang, Lin; Watmough, James

    2015-12-01

    In many predator-prey models, delay has a destabilizing effect and induces oscillations; while in many competition models, delay does not induce oscillations. By analyzing a rather simple delayed intraguild predation model, which combines both the predator-prey relation and competition, we show that delay in intraguild predation models promotes very complex dynamics. The delay can induce stability switches exhibiting a destabilizing role as well as a stabilizing role. It is shown that three types of bistability are possible: one stable equilibrium coexists with another stable equilibrium (node-node bistability); one stable equilibrium coexists with a stable periodic solution (node-cycle bistability); one stable periodic solution coexists with another stable periodic solution (cycle-cycle bistability). Numerical simulations suggest that delay can also induce chaos in intraguild predation models.

  14. A novel optic bistable device with very low threshold intensity using photorefractive films

    Science.gov (United States)

    Wang, Sean X.; Sun, Yuankun; Trivedi, Sudhir B.; Li, Guifang

    1994-08-01

    Brimrose Corporation of America reports the successful completion of the SBIR Phase I research in low-threshold intensity optical bistable devices using photorefractive nonlinearity. A thin photorefractive film optical bistable device was proposed in the Phase I proposal. The feasibility of this device was theoretically investigated. The theoretical feasibility study formulates the materials requirements in such a kind of configuration for Phase II research. In addition, we have proposed and investigated another configuration of optical bistable devices that do not require advanced photorefractive materials, namely, the self-pumped phase conjugator. We have successfully demonstrated a low-threshold optical bistable operation in a KNSBN:CU crystal. To the best of our knowledge, the threshold of 650 mW/sq. cm is the lowest of its kind to be achieved so far.

  15. Innovative Energy Harvester Design Using Bistable Mechanism With Compensational Springs In Gravity Field

    International Nuclear Information System (INIS)

    Vysotskyi, Bogdan; Parrain, Fabien; Lefeuvre, Elie; Aubry, Denis; Gaucher, Philippe

    2016-01-01

    The purpose of the presented work is to introduce the novel design of electrostatic energy harvester using bistable mechanism with compensational springs in gravity field capable of providing the output of several μW under the excitation of extremely small amplitude (up to 0.2g) and low frequency (10-100Hz). Presented energy harvester uses the bistable hysteresis modification to achieve low-frequency low-amplitude sensibility. It was demonstrated with finite element modelling (FEM) that hysteresis width produced by bistability is changing with a constant linear coefficient as a function of a compensational spring stiffness and thus a device sensitivity could be adjusted to the minimum point for the amplitude of external excitation. Further, highly non-linear bistable double curved beam mechanism assures the high sensitivity in frequencial domain due to the non-defined bandwidth. The equivalent circuit technique is used for simulating the device performance. (paper)

  16. Geometric and potential dynamics interpretation of the optic ring resonator bistability

    Science.gov (United States)

    Chiangga, S.; Chittha, T.; Frank, T. D.

    2015-07-01

    The optical bistability is a fundamental nonlinear feature of the ring resonator. A geometric and potential dynamics interpretation of the bistability is given. Accordingly, the bistability of the nonlinear system is shown to be a consequence of geometric laws of vector calculus describing the resonator ring. In contrast, the so-called transcendental relations that have been obtained in the literature in order to describe the optical wave are interpreted in terms of potential dynamical systems. The proposed novel interpretation provides new insights into the nature of the ring resonator optical bistability. The fundamental work by Rukhlenko, Premaratne and Agrawal (2010) as well as a more recent study by Chiangga, Pitakwongsaporn, Frank and Yupapin (2013) are considered.

  17. Bistable output from a coupled-resonator vertical-cavity laser diode

    International Nuclear Information System (INIS)

    Fischer, A. J.; Choquette, K. D.; Chow, W. W.; Allerman, A. A.; Geib, K.

    2000-01-01

    We report a monolithic coupled-resonator vertical-cavity laser with an ion-implanted top cavity and a selectively oxidized bottom cavity which exhibits bistable behavior in the light output versus injection current. Large bistability regions over current ranges as wide as 18 mA have been observed with on/off contrast ratios of greater than 20 dB. The position and width of the bistability region can be varied by changing the bias to the top cavity. Switching between on and off states can be accomplished with changes as small as 250 μW to the electrical power applied to the top cavity. The bistable behavior is the response of the nonlinear susceptibility in the top cavity to the changes in the bottom intracavity laser intensity as the bottom cavity reaches the thermal rollover point

  18. Harnessing the bistable composite shells to design a tunable phononic band gap structure

    Science.gov (United States)

    Li, Yi; Xu, Yanlong

    2018-02-01

    By proposing a system composed of an array of bistable composite shells immersed in air, we develop a new class of periodic structure to control the propagation of sound. Through numerical investigation, we find that the acoustic band gap of this system can be switched on and off by triggering the snap through deformation of the bistable composite shells. The shape of cross section and filling fraction of unit cell can be altered by different number of bistable composite shells, and they have strong impact on the position and width of the band gap. The proposed concept paves the way of using the bistable structures to design a new class of metamaterials that can be enable to manipulate sound.

  19. Microscopic observation of zenithal bistable switching in nematic devices with different surface relief structures

    International Nuclear Information System (INIS)

    Uche, C; Elston, S J; Parry-Jones, L A

    2005-01-01

    Nematic liquid crystals have been shown to exhibit zenithal electro-optic bistability in devices containing sinusoidal and deformed sinusoidal gratings. Recently it has been shown that zenithal bistable states can also be supported at isolated edges of square gratings. In this paper, we present microscopic observations of bistability in cells containing sinusoidal gratings and long-pitch square gratings. We have also investigated a novel display based on square wells. High frame-rate video microscopy was used to obtain time-sequenced images when the devices were switched with monopolar pulses. These show that zenithal bistable switching can occur by two different processes: (i) domain growth (observed in cells containing sinusoidal gratings) and (ii) homogenous switching (observed in cells containing isolated edges

  20. Optical bistability in the oscillation of an inhomogeneously broadened quasi-three-level laser

    International Nuclear Information System (INIS)

    Liu, Junhai; Tian, Xueping

    2013-01-01

    A theoretical modeling analysis is presented to study the optical bistability exhibited in the oscillation of an inhomogeneously broadened quasi-three-level laser. All the major characteristics of optical bistability depend on two normalized parameters, f and x a , which are defined by f = I sat,a /I sat,m and x a = 2α a0 p a /δ and are related to measurable properties of the laser medium. In comparison with the case of a homogeneously broadened laser, the essential condition for the occurrence of such bistability, f a /(x a + 1), turns out to be the same, whereas the intensities at the up- and down-thresholds are substantially increased and the bistability range is reduced. (paper)

  1. A bistable switch in dynamic thiodepsipeptide folding and template-directed ligation.

    Science.gov (United States)

    Mukherjee, Rakesh; Cohen-Luria, Rivka; Wagner, Nathaniel; Ashkenasy, Gonen

    2015-10-12

    Bistable reaction networks provide living cells with chemically controlled mechanisms for long-term memory storage. Such networks are also often switchable and can be flipped from one state to the other. We target here a major challenge in systems chemistry research, namely developing synthetic, non-enzymatic, networks that mimic such a complex function. Therefore, we describe a dynamic network that depending on initial thiodepsipeptide concentrations leads to one of two distinct steady states. This bistable system is readily switched by applying the appropriate stimuli. The relationship between the reaction network topology and its capacity to invoke bistability is then analyzed by control experiments and theory. We suggest that demonstrating bistable behavior using synthetic networks further highlights their possible role in early evolution, and may shine light on potential utility for novel applications, such as chemical memories. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Angular dependence of the exchange bias for the bistable state

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Yuhao [College of Physics and Electronic Information, Shanxi Normal University, Linfen 041004 (China); Research College of materials science, Shanxi Normal University, Linfen 041004 (China); Xu, Xiaohong, E-mail: xuxh@dns.sxnu.edu.cn [Research College of materials science, Shanxi Normal University, Linfen 041004 (China); Key Laboratory of Magnetic Molecules and Magnetic Information Materials, Ministry of Education, Shanxi Normal University, Linfen 041004 (China)

    2017-06-15

    The angular dependence of the exchange bias (ADEB) has been investigated in detail when the exchange-coupled ferromagnetic (FM)/antiferromagnetic (AFM) bilayer is in the bistable state. Complete and incomplete jump phenomena were found at the intrinsic easy and hard axes, when they pass through two special positions making the angular deviation of 58.2826° and 121.7174° from the easy axis of the uniaxial anisotropy, respectively. The combination of these different types of the jump phenomena at the intrinsic easy and hard axes yields five distinct types of the ADEB. The physical condition for each type of ADEB is established. Additionally, the extreme value problem of the exchange bias field and coercivity are also discussed, which is an important technological issue in the design of the magnetoresistive and spintronic devices. These results enable us to make a comprehensive understanding of the experimental ADEB curves.

  3. Synaptic Bistability Due to Nucleation and Evaporation of Receptor Clusters

    KAUST Repository

    Burlakov, V. M.

    2012-01-10

    We introduce a bistability mechanism for long-term synaptic plasticity based on switching between two metastable states that contain significantly different numbers of synaptic receptors. One state is characterized by a two-dimensional gas of mobile interacting receptors and is stabilized against clustering by a high nucleation barrier. The other state contains a receptor gas in equilibrium with a large cluster of immobile receptors, which is stabilized by the turnover rate of receptors into and out of the synapse. Transitions between the two states can be initiated by either an increase (potentiation) or a decrease (depotentiation) of the net receptor flux into the synapse. This changes the saturation level of the receptor gas and triggers nucleation or evaporation of receptor clusters. © 2012 American Physical Society.

  4. Controllable optical bistability and multistability in a graphene monolayer system

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Duo, E-mail: zhangduo10@126.com [School of Electrical and Electronic Engineering, Wuhan Polytechnic University, Wuhan 430023 (China); Sun, Zhaoyu [School of Electrical and Electronic Engineering, Wuhan Polytechnic University, Wuhan 430023 (China); Ding, Chunling [School of Physics and Electronics, Henan University, Kaifeng 475004 (China); Yu, Rong [School of Science, Hubei Province Key Laboratory of Intelligent Robot, Wuhan Institute of Technology, Wuhan 430073 (China); Yang, Xiaoxue [Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2016-02-15

    We theoretically investigate the behavior of optical bistability (OB) and optical multistability (OM) in a graphene monolayer system driven by an elliptically polarized control field and a right-hand circularly polarized probe field. Our numerical results show that it is easy to realize the transition from OB to OM or vice versa by adjusting the frequency detunings of the probe field and the control field, as well as the polarization-dependent phase difference between the two components of the control laser field. The influences of the intensity of the control field and the cooperation parameter on the OB behavior are also discussed in detail. These results may provide some new possibilities for technological applications in optoelectronics and solid-state quantum information science.

  5. Coherent-feedback-induced controllable optical bistability and photon blockade

    International Nuclear Information System (INIS)

    Liu, Yu-Long; Liu, Zhong-Peng; Zhang, Jing

    2015-01-01

    It is well known that some nonlinear phenomena such as strong photon blockade are difficult to observe in optomechanical systems with current experimental technology. Here we present a coherent feedback control strategy in which a linear cavity is coherently controlled by an optomechanical controller in a feedback manner. The coherent feedback loop transfers quantum nonlinearity from the controller to the controlled cavity causing destructive quantum interference to occur, and making it possible to observe strong nonlinear effects. With the help of the coherent feedback loop, large and tunable bistability and strong photon blockade of the cavity modes can be achieved even in the optomechanical weak coupling regime. Additionally, the coherent feedback loop leads to two-photon and multiphoton tunnelings for the controlled linear cavity, which are also typical quantum nonlinear phenomena. We hope that our work can give new perspectives on engineering nonlinear interactions in quantum systems. (paper)

  6. Oscillatory bistability of real-space transfer in semiconductor heterostructures

    Science.gov (United States)

    Do˙ttling, R.; Scho˙ll, E.

    1992-01-01

    Charge transport parallel to the layers of a modulation-doped GaAs/AlxGa1-xAs heterostructure is studied theoretically. The heating of electrons by the applied electric field leads to real-space transfer of electrons from the GaAs into the adjacent AlxGa1-xAs layer. For sufficiently large dc bias, spontaneous periodic 100-GHz current oscillations, and bistability and hysteretic switching transitions between oscillatory and stationary states are predicted. We present a detailed investigation of complex bifurcation scenarios as a function of the bias voltage U0 and the load resistance RL. For large RL subcritical Hopf bifurcations and global bifurcations of limit cycles are displayed.

  7. Effects of non-latching blast valves on the source term and consequences of the design-basis accidents in the Device Assembly Facility (DAF)

    International Nuclear Information System (INIS)

    Nguyen, D.H.

    1993-08-01

    The analysis of the Design-Basis Accidents (DBA) involving high explosives (HE) and Plutonium (Pu) in the assembly cell of the Device Assembly Facility (DAF), which was completed earlier, assumed latching blast valves in the ventilation system of the assembly cell. Latching valves effectively sealed a release path through the ventilation duct system. However, the blast valves in the assembly cell, as constructed are actually non-latching valves, and would reopen when the gas pressure drops to 0.5 psi above one atmosphere. Because the reopening of the blast valves provides an additional release path to the environment, and affects the material transport from the assembly cell to other DAF buildings, the DOE/NV DAF management has decided to support an additional analysis of the DAF's DBA to account for the effects of non-latching valves. Three cases were considered in the DAF's DBA, depending on the amount of HE and Pu involved, as follows: Case 1 -- 423 number-sign HE, 16 kg Pu; Case 2 -- 150 number-sign HE 10 kg Pu; Case 3 -- 55 number-sign HE 5 kg Pu. The results of the analysis with non-latching valves are summarized

  8. Design of new central solenoid for SST-1

    Science.gov (United States)

    Prasad, Upendra; Pradhan, Subrata; Ghate, Mahesh; Raj, Piyush; Tanna, V. L.; Khan, Ziauddin; Roy, Swati; Santra, Prosenjit; Biswas, Prabal; Sharma, A. N.; Khristi, Yohan; Kanaber, Deven; Varmora, Pankaj

    2017-04-01

    The key role of central solenoid (CS) magnet of a Tokamak is for gas breakdown, ramp up and maintaining of plasma current. The magnetic flux change in CS along with other PF coils generates magnetic null and induces electric field in toroidal direction. The induced toroidal electric field accelerates the residual electrons which collide with the neutrals and an avalanche takes place which led to the net plasma in the vacuum vessel of a Tokamak. In order to maximize the CS volt-sec capability, the higher magnetic field with a greater magnetic flux linkage is necessary. In order to facilitate all these requirements of SST-1 a new superconducting CS has been designed for SST-1. The design of new central solenoid has two bases; first one is physics and second is smart engineering in limited bore diameter of ∼ 655 mm. The physics basis of the design includes volt-sec storage capacity of ∼ 0.8 volt-sec, magnetic field null around 0.2 m over major radius of 1.1 m and toroidal electric field of ∼ 0.3 volt/m. The engineering design of new CS consists of Nb3Sn cable in conduit conductor (CICC) of operating current of 14 kA @ 4.5 K at 6 T, consolidated winding pack, smart quench detection system, protection system, housing cryostat and conductor terminations and joint design. The winding pack consists of 576 numbers of turns distributed in four layers with 0.75 mm FRP tape soaked with cyanide Easter based epoxy resin turn insulation and 3 mm of ground insulation. The interlayer low resistance (∼1 nΩ) terminal praying hand joints at 14 kA at 4.5 K has been designed for making winding pack continuous. The total height of winding pack is 2500 mm. The stored energy of this winding pack is ∼ 3 MJ at 14 kA of operating current. The expected heat load at cryogenic temperature is ∼ 10 W per layer, which requires helium mass flow rate of 1.4 g/s at 1.4 bars @ 4.5 K. The typical diameter and height of housing cryostat are 650 mm and 2563 mm with 80 K shield respectively

  9. Design of new central solenoid for SST-1

    International Nuclear Information System (INIS)

    Prasad, Upendra; Pradhan, Subrata; Ghate, Mahesh; Raj, Piyush; Tanna, V L; Khan, Ziauddin; Roy, Swati; Santra, Prosenjit; Biswas, Prabal; Sharma, A N; Khristi, Yohan; Kanaber, Deven; Varmora, Pankaj

    2017-01-01

    The key role of central solenoid (CS) magnet of a Tokamak is for gas breakdown, ramp up and maintaining of plasma current. The magnetic flux change in CS along with other PF coils generates magnetic null and induces electric field in toroidal direction. The induced toroidal electric field accelerates the residual electrons which collide with the neutrals and an avalanche takes place which led to the net plasma in the vacuum vessel of a Tokamak. In order to maximize the CS volt-sec capability, the higher magnetic field with a greater magnetic flux linkage is necessary. In order to facilitate all these requirements of SST-1 a new superconducting CS has been designed for SST-1. The design of new central solenoid has two bases; first one is physics and second is smart engineering in limited bore diameter of ∼ 655 mm. The physics basis of the design includes volt-sec storage capacity of ∼ 0.8 volt-sec, magnetic field null around 0.2 m over major radius of 1.1 m and toroidal electric field of ∼ 0.3 volt/m. The engineering design of new CS consists of Nb3Sn cable in conduit conductor (CICC) of operating current of 14 kA @ 4.5 K at 6 T, consolidated winding pack, smart quench detection system, protection system, housing cryostat and conductor terminations and joint design. The winding pack consists of 576 numbers of turns distributed in four layers with 0.75 mm FRP tape soaked with cyanide Easter based epoxy resin turn insulation and 3 mm of ground insulation. The interlayer low resistance (∼1 nΩ) terminal praying hand joints at 14 kA at 4.5 K has been designed for making winding pack continuous. The total height of winding pack is 2500 mm. The stored energy of this winding pack is ∼ 3 MJ at 14 kA of operating current. The expected heat load at cryogenic temperature is ∼ 10 W per layer, which requires helium mass flow rate of 1.4 g/s at 1.4 bars @ 4.5 K. The typical diameter and height of housing cryostat are 650 mm and 2563 mm with 80 K shield respectively

  10. Design of new superconducting central solenoid of SST-1 tokamak

    International Nuclear Information System (INIS)

    Prasad, Upendra; Pradhan, Subrata; Ghate, Mahesh

    2015-01-01

    The key role of the central solenoid (CS) magnet of a Tokamak is for gas breakdown, ramp up and maintaining of plasma current for longer duration. The magnetic flux change in CS along with other PF coils generates magnetic null and induces electric field in toroidal direction. The induced toroidal electric field accelerates the residual electrons which collide with the neutrals and an avalanche takes place which led to the net plasma in the vacuum vessel of a Tokamak. In order to maximize the CS volt-sec capability, the higher magnetic field with a greater magnetic flux linkage is necessary. In order to facilitate all these requirements of SST-1 a new superconducting CS has been designed for SST-1. The design of new central solenoid has two bases; first one is physics and second is smart engineering in limited bore diameter of ∼655 mm. The physics basis of the design includes volt-sec storage capacity of ∼0.8 volt-sec, magnetic field null around 0.2 m over major radius of 1.1 m and toroidal electric field of ∼0.3 volt/m.The engineering design of new CS consists of Nb 3 Sn cable in conduit conductor (CICC) of operating current of 14 kA @ 4.5 K at 6 T, consolidated winding pack, smart quench detection system, protection system, housing cryostat and conductor terminations and joint design. The winding pack consists of 576 numbers of turns distributed in four layers with 0.75 mm FRP tape soaked with cyanide Easter based epoxy resin turn insulation and 3 mm of ground insulation. The inter-layer low resistance (∼1 nΩ) at 14 kA @ 4.5 K terminal praying hand joints has been designed for making winding pack continuous. The total height of winding pack is 2500 mm. The stored energy of this winding pack is ∼3 MJ at 14 kA of operating current. The expected heat load at cryogenic temperature is ∼10 W per layer, which requires helium mass flow rate of 1.4 g/s at 1.4 bars @ 4.5 K. The typical diameter and height of housing cryostat are 650 mm and 2563 mm with 80 K

  11. Optical bistability of optical fiber ring doped by Erbium and quantum dots

    International Nuclear Information System (INIS)

    Safari, S.; Tofighi, S.; Bahrampour, A.; Sajad, B.; Shahshahani, F.

    2012-01-01

    In this paper, theoretical analysis of the steady state behavior of the optical bistability in an optical fiber ring doped by Erbium and quantum dots is presented. The up and down switching power is calculated and the dependence of the switching power on different fiber ring parameters is investigated. The switching power for this type of optical bistability device is obtained much lower than the fiber ring which its half length is doped by Erbium ion.

  12. A predictive coding account of bistable perception - a model-based fMRI study.

    Directory of Open Access Journals (Sweden)

    Veith Weilnhammer

    2017-05-01

    Full Text Available In bistable vision, subjective perception wavers between two interpretations of a constant ambiguous stimulus. This dissociation between conscious perception and sensory stimulation has motivated various empirical studies on the neural correlates of bistable perception, but the neurocomputational mechanism behind endogenous perceptual transitions has remained elusive. Here, we recurred to a generic Bayesian framework of predictive coding and devised a model that casts endogenous perceptual transitions as a consequence of prediction errors emerging from residual evidence for the suppressed percept. Data simulations revealed close similarities between the model's predictions and key temporal characteristics of perceptual bistability, indicating that the model was able to reproduce bistable perception. Fitting the predictive coding model to behavioural data from an fMRI-experiment on bistable perception, we found a correlation across participants between the model parameter encoding perceptual stabilization and the behaviourally measured frequency of perceptual transitions, corroborating that the model successfully accounted for participants' perception. Formal model comparison with established models of bistable perception based on mutual inhibition and adaptation, noise or a combination of adaptation and noise was used for the validation of the predictive coding model against the established models. Most importantly, model-based analyses of the fMRI data revealed that prediction error time-courses derived from the predictive coding model correlated with neural signal time-courses in bilateral inferior frontal gyri and anterior insulae. Voxel-wise model selection indicated a superiority of the predictive coding model over conventional analysis approaches in explaining neural activity in these frontal areas, suggesting that frontal cortex encodes prediction errors that mediate endogenous perceptual transitions in bistable perception. Taken together

  13. Optical bistability of a thin film of resonant atoms in a phase-sensitive thermostate

    International Nuclear Information System (INIS)

    Basharov, A.M.

    1995-01-01

    It is shown theoretically that when a thin film of two-level atoms interacting with a resonant coherent electromagnetic wave is additionally illuminated with a squeezed field, a bistable transmission/reflection regime for coherent waves is obtained. This regime depends strongly on the phase difference between the coherent and the squeezed fields. New regimes, including a bistable regime, for the interaction of a coherent field with a film of resonant atoms are predicted based on this phenomenon. 14 refs., 5 figs

  14. Optical bistability in a single-sided cavity coupled to a quantum channel

    Science.gov (United States)

    Payravi, M.; Solookinejad, Gh; Jabbari, M.; Nafar, M.; Ahmadi Sangachin, E.

    2018-06-01

    In this paper, we discuss the long wavelength optical reflection and bistable behavior of an InGaN/GaN quantum dot nanostructure coupled to a single-sided cavity. It is found that due to the presence of a strong coupling field, the reflection coefficient can be controlled at long wavelength, which is essential for adjusting the threshold of reflected optical bistability. Moreover, the phase shift features of the reflection pulse inside an electromagnetically induced transparency window are also discussed.

  15. Bistability of heat transfer of a viscous liquid under conditions of flow channel

    International Nuclear Information System (INIS)

    Melkikh, A.V.; Seleznev, V.D.

    2001-01-01

    The heat exchange model for a viscous liquid flowing under the pressure drop effect in a tube, surrounded by the medium with a lower temperature, is considered. It is shown that the system bistable behavior is possible by availability of the liquid viscosity exponential dependence on the temperature and by negligible dissipative heat release. The transitions between cold and hot flows in this case should proceed by a jump. The liquid and channel parameters, whereby the bistability may be observed, are determined [ru

  16. Heat dissipation and information flow for delayed bistable Langevin systems near coherence resonance.

    Science.gov (United States)

    Xiao, Tiejun

    2016-11-01

    In this paper, stochastic thermodynamics of delayed bistable Langevin systems near coherence resonance is discussed. We calculate the heat dissipation rate and the information flow of a delayed bistable Langevin system under various noise intensities. Both the heat dissipation rate and the information flow are found to be bell-shaped functions of the noise intensity, which implies that coherence resonance manifests itself in the thermodynamic properties.

  17. Bistable laser device with multiple coupled active vertical-cavity resonators

    Science.gov (United States)

    Fischer, Arthur J.; Choquette, Kent D.; Chow, Weng W.

    2003-08-19

    A new class of bistable coupled-resonator vertical-cavity semiconductor laser devices has been developed. These bistable laser devices can be switched, either electrically or optically, between lasing and non-lasing states. A switching signal with a power of a fraction of a milliwatt can change the laser output of such a device by a factor of a hundred, thereby enabling a range of optical switching and data encoding applications.

  18. A predictive coding account of bistable perception - a model-based fMRI study.

    Science.gov (United States)

    Weilnhammer, Veith; Stuke, Heiner; Hesselmann, Guido; Sterzer, Philipp; Schmack, Katharina

    2017-05-01

    In bistable vision, subjective perception wavers between two interpretations of a constant ambiguous stimulus. This dissociation between conscious perception and sensory stimulation has motivated various empirical studies on the neural correlates of bistable perception, but the neurocomputational mechanism behind endogenous perceptual transitions has remained elusive. Here, we recurred to a generic Bayesian framework of predictive coding and devised a model that casts endogenous perceptual transitions as a consequence of prediction errors emerging from residual evidence for the suppressed percept. Data simulations revealed close similarities between the model's predictions and key temporal characteristics of perceptual bistability, indicating that the model was able to reproduce bistable perception. Fitting the predictive coding model to behavioural data from an fMRI-experiment on bistable perception, we found a correlation across participants between the model parameter encoding perceptual stabilization and the behaviourally measured frequency of perceptual transitions, corroborating that the model successfully accounted for participants' perception. Formal model comparison with established models of bistable perception based on mutual inhibition and adaptation, noise or a combination of adaptation and noise was used for the validation of the predictive coding model against the established models. Most importantly, model-based analyses of the fMRI data revealed that prediction error time-courses derived from the predictive coding model correlated with neural signal time-courses in bilateral inferior frontal gyri and anterior insulae. Voxel-wise model selection indicated a superiority of the predictive coding model over conventional analysis approaches in explaining neural activity in these frontal areas, suggesting that frontal cortex encodes prediction errors that mediate endogenous perceptual transitions in bistable perception. Taken together, our current work

  19. Evidence for distinct mechanisms underlying attentional priming and sensory memory for bistable perception.

    Science.gov (United States)

    Brinkhuis, M A B; Kristjánsson, Á; Brascamp, J W

    2015-08-01

    Attentional selection in visual search paradigms and perceptual selection in bistable perception paradigms show functional similarities. For example, both are sensitive to trial history: They are biased toward previously selected targets or interpretations. We investigated whether priming by target selection in visual search and sensory memory for bistable perception are related. We did this by presenting two trial types to observers. We presented either ambiguous spheres that rotated over a central axis and could be perceived as rotating in one of two directions, or search displays in which the unambiguously rotating target and distractor spheres closely resembled the two possible interpretations of the ambiguous stimulus. We interleaved both trial types within experiments, to see whether priming by target selection during search trials would affect the perceptual outcome of bistable perception and, conversely, whether sensory memory during bistable perception would affect target selection times during search. Whereas we found intertrial repetition effects among consecutive search trials and among consecutive bistable trials, we did not find cross-paradigm effects. Thus, even though we could ascertain that our experiments robustly elicited processes of both search priming and sensory memory for bistable perception, these same experiments revealed no interaction between the two.

  20. Cell individuality: the bistable gene expression of the type III secretion system in Dickeya dadantii 3937.

    Science.gov (United States)

    Zeng, Quan; Laiosa, Michael D; Steeber, Douglas A; Biddle, Eulandria M; Peng, Quan; Yang, Ching-Hong

    2012-01-01

    Dickeya dadantii 3937 is a gram-negative phytopathogenic bacterium that expresses genes encoding a type III secretion system (T3SS) in a bistable pattern when cultured in a homogeneous minimal media. In this work, we further characterized the bistable gene expression of T3SS at the single-cell level. We demonstrated that bistable expression of the HrpL-regulon genes, such as hrpA and hrpN, is controlled by the same regulatory mechanism. We also showed that the expression level of the T3SS master regulatory gene hrpL plays an important role in the development of the bistable expression of hrpA. A high expression level of hrpL is required but unable to guarantee the high-state expression of hrpA in a cell. In addition, bistable expression patterns of T3SS genes in other gram-negative pathogens of the Enterobacteriaceae and Pseudomonadaceae families were also described in this study. This suggests that the T3SS bistability might be a conserved population behavior in several gram-negative bacterial pathogens.

  1. Investigation of a bistable dual-stage vibration isolator under harmonic excitation

    International Nuclear Information System (INIS)

    Yang, Kai; Huang, Hai; Harne, R L; Wang, K W

    2014-01-01

    This study explores the steady-state performance of a dual-stage vibration isolator, which is configured by a bistable oscillator and a linear oscillator. The potential force of the bistable stage comprises negative linear and positive cubic nonlinear stiffnesses such that the two restoring force contributions may counterbalance to minimize dynamic force transmission. By applying a first-order harmonic balance, it is predicted that the bistable dual-stage isolator may significantly outperform an equivalent pure linear dual-stage isolator. This conclusion is verified through a series of numerical investigations. Following a parametric study, design guidelines are detailed to achieve performance improvements. Then, the ‘valley’ response, which is the special phenomenon of the bistable dual-stage isolator due to the counterbalance of the negative linear and positive nonlinear potential forces, is revealed and quantitatively explained. Numerical studies demonstrate the role of initial conditions, and it is shown that the likelihood of beneficial single periodic valley and intra-well responses for isolation purposes can be increased by greater bistable stage damping. Finally, a bistable dual-stage isolator prototype is developed and tested, and the numerical and experimental results verify the theoretical predictions. (paper)

  2. Magnetic-field induced bistability in a quasi-one-dimensional semiconductor microcavity

    International Nuclear Information System (INIS)

    Zhang, Chuanyi; Zhang, Weifeng

    2015-01-01

    We theoretically study the magnetic-field induced bistability in a quasi-one-dimensional semiconductor microcavity. A critical magnetic field is obtained, and the bistability appears if a magnetic field is greater than the critical value. For a positive energy detuning of the pump from the bare exciton polaritons, one bistability loop first emerges, then it divides into two loops, and finally one of them vanishes with the increasing magnetic field. This phenomenon originates from the magnetic-field modulated interactions for opposite spins. In the variational process, there are two important effects: one is a logic gate with a small variation of the excitation laser, and the other is a spin texture like skyrmion and this texture is periodic if the energy detuning varies periodically in real space, which is useful for designing the spin-dependent optoelectronic devices. - Highlights: • We study the bistability induced by a magnetic field in a microcavity. • One bistability loop can divide into two, and then the two loops return to one. • A spin texture like skyrmion and logic gate arise in the variation of bistability loop

  3. The Independent and Shared Mechanisms of Intrinsic Brain Dynamics: Insights From Bistable Perception

    Directory of Open Access Journals (Sweden)

    Teng Cao

    2018-04-01

    Full Text Available In bistable perception, constant input leads to alternating perception. The dynamics of the changing perception reflects the intrinsic dynamic properties of the “unconscious inferential” process in the brain. Under the same condition, individuals differ in how fast they experience the perceptual alternation. In this study, testing many forms of bistable perception in a large number of observers, we investigated the key question of whether there is a general and common mechanism or multiple and independent mechanisms that control the dynamics of the inferential brain. Bistable phenomena tested include binocular rivalry, vase-face, Necker cube, moving plaid, motion induced blindness, biological motion, spinning dancer, rotating cylinder, Lissajous-figure, rolling wheel, and translating diamond. Switching dynamics for each bistable percept was measured in 100 observers. Results show that the switching rates of subsets of bistable percept are highly correlated. The clustering of dynamic properties of some bistable phenomena but not an overall general control of switching dynamics implies that the brain’s inferential processes are both shared and independent – faster in constructing 3D structure from motion does not mean faster in integrating components into an objects.

  4. The influence of the iron shield of the solenoid on spin tracking

    Directory of Open Access Journals (Sweden)

    Toprek Dragan

    2005-01-01

    Full Text Available The influence of the iron shield of the solenoid on spin tracking is studied in this paper. In the case of the 200 MeV proton, the study has been numerically done in the ZGOUBI code. The distribution of the magnetic field was done by POISSON. We have come to the conclusion that the influence of the solenoid’s shielding on spin tracking is the same at its entrance and exit and that is directly proportional to the intensity of the magnetic induction B on the axis of the solenoid. We have also determined that the influence of the solenoid’s shielding is much stronger on transversal components of the spin than on its longitudinal component. The differences between components of the spin for the shielded and not-shielded solenoid diminish with the in crease in the distance from the solenoid.

  5. The electromagnetic calorimeter for the solenoidal tracker at RHIC. A Conceptual Design Report

    Energy Technology Data Exchange (ETDEWEB)

    Beddo, M.E.; Bielick, E.; Dawson, J.W. [Argonne National Lab., IL (United States)] [and others; The STAR EMC Collaboration

    1993-09-22

    This report discusses the following on the electromagnetic calorimeter for the solenoidal tracker at RHIC: conceptual design; the physics of electromagnetic calorimetry in STAR; trigger capability; integration into STAR; and cost, schedule, manpower, and funding.

  6. Proceedings of the international workshop on solenoidal detectors for the SSC

    International Nuclear Information System (INIS)

    Abe, Fumio; Hasegawa, Katsuo

    1990-07-01

    This issue is the collection of the papers presented at the International Workshop on solenoidal detectors for the Superconducting Super Collider (SSC). The 48 of the presented papers are indexed individually. (J.P.N.)

  7. Applications of a superconducting solenoidal separator in the experimental investigation of nuclear reactions

    International Nuclear Information System (INIS)

    Hinde, D J; Carter, I P; Dasgupta, M; Simpson, E C; Cook, K J; Kalkal, Sunil; Luong, D H; Williams, E

    2017-01-01

    This paper describes applications of a novel superconducting solenoidal separator, with magnetic fields up to 8 Tesla, for studies of nuclear reactions using the Heavy Ion Accelerator Facility at the Australian National University. (paper)

  8. Design features of the solenoid magnets for the central cell of the MFTF-B

    International Nuclear Information System (INIS)

    Wohlwend, J.W.; Tatro, R.E.; Ring, D.S.

    1981-01-01

    The 14 superconducting solenoid magnets which form the central cell of the MFTF-B are being designed and fabricated by General Dynamics for the Lawrence Livermore National Laboratory. Each solenoid coil has a mean diameter of five meters and contains 600 turns of a proven conductor type. Structural loading resulting from credible fault events, cooldown and warmup requirements, and manufacturing processes consistent with other MFTF-B magnets have been considered in the selection of 304 LN as the structural material for the magnet. The solenoid magnets are connected by 24 intercoil beams and 20 solid struts which resist the longitudinal seismic and electromagnetic attractive forces and by 24 hanger/side supports which react magnet dead weight and seismic loads. A modular arrangement of two solenoid coils within a vacuum vessel segment allow for sequential checkout and installation

  9. Impact of detector solenoid on the Compact Linear Collider luminosity performance

    CERN Document Server

    Inntjore Levinsen, Y.; Tomás, Rogelio; Schulte, Daniel

    2014-05-27

    In order to obtain the necessary luminosity with a reasonable amount of beam power, the Compact Linear Collider (CLIC) design includes an unprecedented collision beam size of {\\sigma} = 1 nm vertically and {\\sigma} = 45 nm horizontally. Given the small and very flat beams, the luminosity can be significantly degraded from the impact of the experimental solenoid field in combination with a large crossing angle. Main effects include y-x'-coupling and increase of vertical dispersion. Additionally, Incoherent Synchrotron Radiation (ISR) from the orbit deflection created by the solenoid field, increases the beam emittance. A detailed study of the impact from a realistic solenoid field and the associated correction techniques for the CLIC Final Focus is presented. In particular, the impact of techniques to compensate the beam optics distortions due to the detector solenoid main field and its overlap with the final focus magnets are shown. The unrecoverable luminosity loss due to ISR has been evaluated, and found to...

  10. Beam collimation and transport of laser-accelerated protons by a solenoid field

    Energy Technology Data Exchange (ETDEWEB)

    Harres, K; Alber, I; Guenther, M; Nuernberg, F; Otten, A; Schuetrumpf, J; Roth, M [Technische Universitaet Darmstadt, Institut fuer Kernphysik, Schlossgartenstrasse 9, 64289 Darmstadt (Germany); Tauschwitz, A; Bagnoud, V [GSI - Hemholtzzentrum fur Schwerionenforschung GmbH, Plasmaphysik and PHELIX, Planckstrasse 1, 64291 Darmstadt (Germany); Daido, H; Tampo, M [Photo Medical Research Center, JAEA, 8-1 Umemidai, Kizugawa-city, Kyoto, 619-0215 (Japan); Schollmeier, M, E-mail: k.harres@gsi.d [Sandia National Laboratories, Albuquerque NM 87185 (United States)

    2010-08-01

    A pulsed high field solenoid was used in a laser-proton acceleration experiment to collimate and transport the proton beam that was generated at the irradiation of a flat foil by a high intensity laser pulse. 10{sup 12} particles at an energy of 2.3 MeV could be caught and transported over a distance of more than 240 mm. Strong space charge effects occur, induced by the high field of the solenoid that forces all co-moving electrons down the the solenoid's axis, building up a strong negative space charge that interacts with the proton beam. This leads to an aggregation of the proton beam around the solenoid's axis and therefore to a stronger focusing effect. The collimation and transport of laser-accelerated protons is the first step to provide these unique beams for further applications like post-acceleration by conventional accelerator structures.

  11. Beam collimation and transport of laser-accelerated protons by a solenoid field

    International Nuclear Information System (INIS)

    Harres, K; Alber, I; Guenther, M; Nuernberg, F; Otten, A; Schuetrumpf, J; Roth, M; Tauschwitz, A; Bagnoud, V; Daido, H; Tampo, M; Schollmeier, M

    2010-01-01

    A pulsed high field solenoid was used in a laser-proton acceleration experiment to collimate and transport the proton beam that was generated at the irradiation of a flat foil by a high intensity laser pulse. 10 12 particles at an energy of 2.3 MeV could be caught and transported over a distance of more than 240 mm. Strong space charge effects occur, induced by the high field of the solenoid that forces all co-moving electrons down the the solenoid's axis, building up a strong negative space charge that interacts with the proton beam. This leads to an aggregation of the proton beam around the solenoid's axis and therefore to a stronger focusing effect. The collimation and transport of laser-accelerated protons is the first step to provide these unique beams for further applications like post-acceleration by conventional accelerator structures.

  12. Confinement of laser plasma by solenoidal field for laser ion source

    International Nuclear Information System (INIS)

    Okamura, M.; Kanesue, T.; Kondo, K.; Dabrowski, R.

    2010-01-01

    A laser ion source can provide high current, highly charged ions with a simple structure. However, it was not easy to control the ion pulse width. To provide a longer ion beam pulse, the plasma drift length, which is the distance between laser target and extraction point, has to be extended and as a result the plasma is diluted severely. Previously, we applied a solenoid field to prevent reduction of ion density at the extraction point. Although a current enhancement by a solenoid field was observed, plasma behavior after a solenoid magnet was unclear because plasma behavior can be different from usual ion beam dynamics. We measured a transverse ion distribution along the beam axis to understand plasma motion in the presence of a solenoid field.

  13. Non-inductive Solenoid-less Plasma Current Start-up in NSTX Using Transient CHI

    International Nuclear Information System (INIS)

    Raman, R.; Mueller, D.; Jarboe, T.R.; Nelson, B.A.; Bell, M.G.; Ono, M.; Bigelow, T.; Kaita, R.; LeBlanc, B.; Lee, K.C.; Maqueda, R.; Menard, J.; Paul, S.; Roquemore, L.

    2007-01-01

    Coaxial Helicity Injection (CHI) has been successfully used in the National Spherical Torus Experiment (NSTX) for a demonstration of closed flux current generation without the use of the central solenoid. The favorable properties of the Spherical Torus (ST) arise from its very small aspect ratio. However, small aspect ratio devices have very restricted space for a substantial central solenoid. Thus methods for initiating the plasma current without relying on induction from a central solenoid are essential for the viability of the ST concept. CHI is a promising candidate for solenoid-free plasma startup in a ST. The method has now produced closed flux current up to 160 kA verifying the high current capability of this method in a large ST built with conventional tokamak components.

  14. Solenoid-free plasma startup in NSTX using transient CHI

    International Nuclear Information System (INIS)

    Raman, R.; Jarboe, T.R.; Nelson, B.A.; Mueller, D.; Bell, M.G.; Bell, R.; Gates, D.; Gerhardt, S.; Hosea, J.; Kaita, R.; Kugel, H.; LeBlanc, B.; Menard, J.; Ono, M.; Paul, S.; Roquemore, L.; Maingi, R.; Maqueda, R.; Nagata, M.; Sabbagh, S.

    2009-01-01

    Experiments in NSTX have now demonstrated the coupling of toroidal plasmas produced by the technique of coaxial helicity injection (CHI) to inductive sustainment and ramp-up of the toroidal plasma current. In these discharges, the central Ohmic transformer was used to apply an inductive loop voltage to discharges with a toroidal current of about 100 kA created by CHI. The coupled discharges have ramped up to >700 kA and transitioned into an H-mode demonstrating compatibility of this startup method with conventional operation. The electron temperature in the coupled discharges reached over 800 eV and the resulting plasma had low inductance, which is preferred for long-pulse high-performance discharges. These results from NSTX in combination with the previously obtained record 160 kA non-inductively generated startup currents in an ST or tokamak in NSTX demonstrate that CHI is a viable solenoid-free plasma startup method for future STs and tokamaks.

  15. Testing of ITER central solenoid coil insulation in an array

    International Nuclear Information System (INIS)

    Jayakumar, R.; Martovetsky, N.N.; Perfect, S.A.

    1995-01-01

    A glass-polyimide insulation system has been proposed by the US team for use in the Central Solenoid (CS) coil of the international Thermonuclear Experimental Reactor (ITER) machine and it is planned to use this system in the CS model coil inner module. The turn insulation will consist of 2 layers of combined prepreg and Kapton. Each layer is 50% overlapped with a butt wrap of prepreg and an overwrap of S glass. The coil layers will be separated by a glass-resin composite and impregnated in a VPI process. Small scale tests on the various components of the insulation are complete. It is planned to fabricate and test the insulation in a 4 x 4 insulated CS conductor array which will include the layer insulation and be vacuum impregnated. The conductor array will be subjected to 20 thermal cycles and 100000 mechanical load cycles in a Liquid Nitrogen environment. These loads are similar to those seen in the CS coil design. The insulation will be electrically tested at several stages during mechanical testing. This paper will describe the array configuration, fabrication: process, instrumentation, testing configuration, and supporting analyses used in selecting the array and test configurations

  16. Conceptual design report for the Solenoidal Tracker at RHIC

    International Nuclear Information System (INIS)

    1992-01-01

    The Solenoidal Tracker At RHIC (STAR) will search for signatures of quark-gluon plasma (QGP) formation and investigate the behavior of strongly interacting matter at high energy density. The emphasis win be the correlation of many observables on an event-by-event basis. In the absence of definitive signatures for the QGP, it is imperative that such correlations be used to identify special events and possible signatures. This requires a flexible detection system that can simultaneously measure many experimental observables. The physics goals dictate the design of star and it's experiment. To meet the design criteria, tracking, momentum analysis, and particle identification of most of the charged particles at midrapidity are necessary. The tracking must operate in conditions at higher than the expected maximum charged particle multiplicities for central Au + Au collisions. Particle identification of pions/kaons for p < 0.7 GeV/c and kaons/protons for p < 1 GeV/c, as well as measurement of decay particles and reconstruction of secondary vertices will be possible. A two-track resolution of 2 cm at 2 m radial distance from, the interaction is expected. Momentum resolution of Δp/p ∼ 0.02 at p = 0.1 GeV/c is required to accomplish the physics, and,Δp/p of several percent at p = 10 GeV/c is sufficient to accurately measure the rapidly failing spectra at high Pt and particles from mini-jets and jets

  17. A superconducting solenoid and press for permanent magnet fabrication

    International Nuclear Information System (INIS)

    Mulcahy, T. M.; Hull, J. R.

    2002-01-01

    For the first time, a superconducting solenoid (SCM) was used to increase the remnant magnetization of sintered NdFeB permanent magnets (PMs). In particular, improved magnetic alignment of commercial-grade PM powder was achieved, as it was axial die pressed into 12.7-mm diameter cylindrical compacts in the 76.2-mm warm bore of a 9-T SCM. The press used to compact the powder is unique and was specifically designed for use with the SCM. Although the press was operated in the batch mode for this proof of concept study, its design is intended to enable automated production. In operation, a simple die and punch set made of nonmagnetic materials was filled with powder and loaded into a nonmagnetic press tube. The cantilevered press tube was inserted horizontally, on a carrier manually advanced along a track, into the SCM. The robustness of the mechanical components and the SCM, in its liquid helium dewar, were specifically designed to allow for insertion and extraction of the magnetic powder and compacts, while operating at 9 T. Compaction was achieved by pressing the punches between the closed end of the press tube and the hydraulic cylinder mounted on the opposite end. Improvements up to 10% in magnetization and 20% in energy products of the permanent magnets were obtained, as the alignment fields were increased above the 2-T maximum field of the electromagnets used in industry. Increases in magnetization of 3% are significant in the mature sintered magnet industry

  18. Conceptual design report for the Solenoidal Tracker at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    The STAR Collaboration

    1992-06-15

    The Solenoidal Tracker At RHIC (STAR) will search for signatures of quark-gluon plasma (QGP) formation and investigate the behavior of strongly interacting matter at high energy density. The emphasis win be the correlation of many observables on an event-by-event basis. In the absence of definitive signatures for the QGP, it is imperative that such correlations be used to identify special events and possible signatures. This requires a flexible detection system that can simultaneously measure many experimental observables. The physics goals dictate the design of star and it`s experiment. To meet the design criteria, tracking, momentum analysis, and particle identification of most of the charged particles at midrapidity are necessary. The tracking must operate in conditions at higher than the expected maximum charged particle multiplicities for central Au + Au collisions. Particle identification of pions/kaons for p < 0.7 GeV/c and kaons/protons for p < 1 GeV/c, as well as measurement of decay particles and reconstruction of secondary vertices will be possible. A two-track resolution of 2 cm at 2 m radial distance from, the interaction is expected. Momentum resolution of {Delta}p/p {approximately} 0.02 at p = 0.1 GeV/c is required to accomplish the physics, and,{Delta}p/p of several percent at p = 10 GeV/c is sufficient to accurately measure the rapidly failing spectra at high Pt and particles from mini-jets and jets.

  19. Inservice diagnostic methods for solenoid-operated valves

    International Nuclear Information System (INIS)

    Kryter, R.C.

    1993-01-01

    Solenoid-operated valves (SOVs) were studied at Oak Ridge National Laboratory as part of the USNRC Nuclear Plant Aging Research (NPAR) Program. The primary objective of the study was to identify, evaluate, and recommend methods for inspection, surveillance, monitoring, and maintenance of SOVs that can help ensure their operational readiness-that is, their ability to perform required safety functions under all anticipated operating conditions, since failure of one of these small and relatively inexpensive devices could have serious consequences under certain circumstances. An earlier (Phase 1) NPAR program study described SOV failure modes and causes and had identified measurable parameters thought to be linked to the progression of everpresent degradation mechanisms that may ultimately result in functional failure of the valve. Using this earlier work as a guide, the present (Phase 11) study focused on devising and then demonstrating the effectiveness of techniques and equipment with which to measure performance parameters that show promise for detecting the presence and trending the progress of such degradations before they reach a critical stage. Intrusive techniques requiring the addition of magnetic or acoustic sensors or the application of special test signals were investigated briefly, but major emphasis was placed on the examination of condition-indicating techniques that can be applied with minimal cost and impact on plant operation. Experimental results are presented that demonstrate the technical feasibility and practicality of the monitoring techniques assessed in the study, and recommendations for further work are provided

  20. A solenoidal and monocusp ion source (SAMIS) (abstract){sup a}{sup b}

    Energy Technology Data Exchange (ETDEWEB)

    Burns, E.J.; Brainard, J.P.; Draper, C.H.; Ney, R.H. [Sandia National Laboratories, Albuquerque, New Mexico 87185-0516 (United States); Leung, K.N.; Perkins, L.T.; Williams, M.D.; Wilde, S.B. [Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720 (United States)

    1996-03-01

    We have developed a new magnetic monocusp ion source for single aperture applications such as neutron generators. Coupling solenoidal magnetic fields on both sides of a monocusp magnetic field has generated over 70{percent} atomic deuterium ions at pressures as low as 0.4 Pa (3 mTorr). This article describes the performance and characteristics of the solenoidal and monocusp ion source. {copyright} {ital 1996 American Institute of Physics.}

  1. Fourier Bessel transform method for efficiently calculating the magnetic field of solenoids

    International Nuclear Information System (INIS)

    Nachamkin, J.; Maggiore, C.J.

    1980-01-01

    A numerical procedure for calculating the magnetic field of a selenoid is derived. Based on the properties of Bessel functions, the procedure is shown to be convergent everywhere, including within the windings of the solenoid. The most critical part of the procedure is detailed in the main text. A simple method is used to ensure numerical significance while allowing economical computational times. In the appendix the procedure is generalized to universal convergence by appropriate partitioning of the solenoid windings

  2. A new scheme for critical current measurements on straight superconducting cables in a large solenoid

    International Nuclear Information System (INIS)

    Rossi, L.; Volpini, G.

    1991-01-01

    The precision of I c measurement of straight superconducting cables in solenoids can be limited by the magnetic field inhomogeneity. A solution in order to improve the field homogeneity based on iron shims is presented here. A conceptual design for the experimental lay-out of a test station to be used in connection with the SOLEMI-I solenoid at the Milan INFN Section (LASA Laboratory) is given

  3. Short-circuited coil in a solenoid circuit of a pulse magnetic field

    International Nuclear Information System (INIS)

    Kivshik, A.F.; Dubrovin, V.Yu.

    1976-01-01

    A short-circuited coil at the end of a long pulse solenoid attenuates the dissipation field by 3-5 times. A plug-configuration field is set up in the middle portion of the pulse solenoid incorporating the short-circuited coils. Shunting of the coils with the induction current by resistor Rsub(shunt) provides for the adjustment of the plug ratio γ

  4. Performance of solenoids versus quadrupoles in focusing and energy selection of laser accelerated protons

    OpenAIRE

    Hofmann, Ingo

    2013-01-01

    Using laser accelerated protons or ions for various applications—for example in particle therapy or short-pulse radiographic diagnostics—requires an effective method of focusing and energy selection. We derive an analytical scaling for the performance of a solenoid compared with a doublet/triplet as function of the energy, which is confirmed by TRACEWIN simulations. Generally speaking, the two approaches are equivalent in focusing capability, if parameters are such that the solenoid length ap...

  5. Development of the experimental setup for investigation of latching of superconducting single-photon detector caused by blinding attack on the quantum key distribution system

    Directory of Open Access Journals (Sweden)

    Elezov M.S.

    2017-01-01

    Full Text Available Recently bright-light control of the SSPD has been demonstrated. This attack employed a “backdoor” in the detector biasing scheme. Under bright-light illumination, SSPD becomes resistive and remains “latched” in the resistive state even when the light is switched off. While the SSPD is latched, Eve can simulate SSPD single-photon response by sending strong light pulses, thus deceiving Bob. We developed the experimental setup for investigation of a dependence on latching threshold of SSPD on optical pulse length and peak power. By knowing latching threshold it is possible to understand essential requirements for development countermeasures against blinding attack on quantum key distribution system with SSPDs.

  6. Bulk chirality effect for symmetric bistable switching of liquid crystals on topologically self-patterned degenerate anchoring surface.

    Science.gov (United States)

    Park, Min-Kyu; Joo, Kyung-Il; Kim, Hak-Rin

    2017-06-26

    We demonstrate a bistable switching liquid crystal (LC) mode utilizing a topologically self-structured dual-groove surface for degenerated easy axes of LC anchoring. In our study, the effect of the bulk elastic distortion of the LC directors on the bistable anchoring surface is theoretically analyzed for balanced bistable states based on a free energy diagram. By adjusting bulk LC chirality, we developed ideally symmetric and stable bistable anchoring and switching properties, which can be driven by a low in-plane pulsed field of about 0.7 V/µm. The fabricated device has a contrast ratio of 196:1.

  7. The effect of magnetic field on bistability in 1D photonic crystal doped by magnetized plasma and coupled nonlinear defects

    International Nuclear Information System (INIS)

    Mehdian, H.; Mohammadzahery, Z.; Hasanbeigi, A.

    2014-01-01

    In this work, we study the defect mode and bistability behavior of 1-D photonic band gap structure with magnetized plasma and coupled nonlinear defects. The transfer matrix method has been employed to investigate the magnetic field effect on defect mode frequency and bistability threshold. The obtained results show that the frequency of defect mode and bistability threshold can be altered, without changing the structure of the photonic multilayer. Therefore, the bistability behavior of the subjected structure in the presence of magnetized plasma can be utilized in manufacturing wide frequency range devices

  8. Influence of Fano interference and incoherent processes on optical bistability in a four-level quantum dot nanostructure

    International Nuclear Information System (INIS)

    Hossein Asadpour, Seyyed; Solookinejad, G; Panahi, M; Ahmadi Sangachin, E

    2016-01-01

    Role of Fano interference and incoherent pumping field on optical bistability in a four-level designed InGaN/GaN quantum dot nanostructure embedded in a unidirectional ring cavity are analyzed. It is found that intensity threshold of optical bistability can be manipulated by Fano interference. It is shown that incoherent pumping fields make the threshold of optical bistability behave differently by Fano interference. Moreover, in the presence of Fano interference the medium becomes phase-dependent. Therefore, the relative phase of applied fields can affect the behaviors of optical bistability and intensity threshold can be controlled easily. (paper)

  9. Conditional bistability, a generic cellular mnemonic mechanism for robust and flexible working memory computations.

    Science.gov (United States)

    Rodriguez, Guillaume; Sarazin, Matthieu; Clemente, Alexandra; Holden, Stephanie; Paz, Jeanne T; Delord, Bruno

    2018-04-30

    Persistent neural activity, the substrate of working memory, is thought to emerge from synaptic reverberation within recurrent networks. However, reverberation models do not robustly explain fundamental dynamics of persistent activity, including high-spiking irregularity, large intertrial variability, and state transitions. While cellular bistability may contribute to persistent activity, its rigidity appears incompatible with persistent activity labile characteristics. Here, we unravel in a cellular model a form of spike-mediated conditional bistability that is robust, generic and provides a rich repertoire of mnemonic computations. Under asynchronous synaptic inputs of the awakened state, conditional bistability generates spiking/bursting episodes, accounting for the irregularity, variability and state transitions characterizing persistent activity. This mechanism has likely been overlooked because of the sub-threshold input it requires and we predict how to assess it experimentally. Our results suggest a reexamination of the role of intrinsic properties in the collective network dynamics responsible for flexible working memory. SIGNIFICANCE STATEMENT This study unravels a novel form of intrinsic neuronal property, i.e. conditional bistability. We show that, thanks of its conditional character, conditional bistability favors the emergence of flexible and robust forms of persistent activity in PFC neural networks, in opposition to previously studied classical forms of absolute bistability. Specifically, we demonstrate for the first time that conditional bistability 1) is a generic biophysical spike-dependent mechanism of layer V pyramidal neurons in the PFC and that 2) it accounts for essential neurodynamical features for the organisation and flexibility of PFC persistent activity (the large irregularity and intertrial variability of the discharge and its organization under discrete stable states), which remain unexplained in a robust fashion by current models

  10. Silicon subsystem mechanical engineering work for the solenoidal detector collaboration

    International Nuclear Information System (INIS)

    Miller, W.O.; Barney, M.; Byrd, D.; Christensen, R.W.; Dransfield, G.; Elder, M.; Gamble, M.; Crastataro, C.; Hanlon, J.; Jones, D.C.

    1995-01-01

    The silicon tracking system (STS) for the Solenoidal Detector Collaboration (SDC) represented an order of magnitude increase in size over any silicon system that had been previously built or even planned. In order to meet its performance requirements, it could not simply be a linear scaling of earlier systems, but instead required completely new concepts. The small size of the early systems made it possible to simply move the support hardware and services largely outside the active volume of the system. For a system five meters long, that simply is not an option. The design of the STS for the SDC experiment was the result of numerous compromises between the capabilities required to do the physics and the limitations imposed by cost, material properties, and silicon strip detector characteristics. From the point of view of the physics, the silicon system should start as close to the interaction point as possible. In addition, the detectors should measure the position of particles passing through them with no errors, and should not deflect or interact with the particles in any way. However, cost, radiation damage, and other factors limiting detector performance dictated, other, more realistic values. Radiation damage limited the inner radius of the silicon detectors to about 9 cm, whereas cost limited the outer radius of the detectors to about 50 cm. Cost also limits the half length of the system to about 250 cm. To control the effects of radiation damage on the detectors required operating the system at a temperature of 0 degrees C or below, and maintaining that temperature throughout life of the system. To summarize, the physics and properties of the silicon strip detectors requires that the detectors be operated at or below 0 degrees C, be positioned very accurately during assembly and remain positionally stable throughout their operation, and that all materials used be radiation hard and have a large thickness for one radiation length

  11. Conceptual design report for the Solenoidal Tracker at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    1992-06-15

    The Solenoidal Tracker At RHIC (STAR) will search for signatures of quark-gluon plasma (QGP) formation and investigate the behavior of strongly interacting matter at high energy density. The emphasis win be the correlation of many observables on an event-by-event basis. In the absence of definitive signatures for the QGP, it is imperative that such correlations be used to identify special events and possible signatures. This requires a flexible detection system that can simultaneously measure many experimental observables. The physics goals dictate the design of star and it's experiment. To meet the design criteria, tracking, momentum analysis, and particle identification of most of the charged particles at midrapidity are necessary. The tracking must operate in conditions at higher than the expected maximum charged particle multiplicities for central Au + Au collisions. Particle identification of pions/kaons for p < 0.7 GeV/c and kaons/protons for p < 1 GeV/c, as well as measurement of decay particles and reconstruction of secondary vertices will be possible. A two-track resolution of 2 cm at 2 m radial distance from, the interaction is expected. Momentum resolution of {Delta}p/p {approximately} 0.02 at p = 0.1 GeV/c is required to accomplish the physics, and,{Delta}p/p of several percent at p = 10 GeV/c is sufficient to accurately measure the rapidly failing spectra at high Pt and particles from mini-jets and jets.

  12. Silicon subsystem mechanical engineering work for the solenoidal detector collaboration

    Energy Technology Data Exchange (ETDEWEB)

    Miller, W.O.; Barney, M.; Byrd, D.; Christensen, R.W.; Dransfield, G.; Elder, M.; Gamble, M.; Crastataro, C.; Hanlon, J.; Jones, D.C. [and others

    1995-02-01

    The silicon tracking system (STS) for the Solenoidal Detector Collaboration (SDC) represented an order of magnitude increase in size over any silicon system that had been previously built or even planned. In order to meet its performance requirements, it could not simply be a linear scaling of earlier systems, but instead required completely new concepts. The small size of the early systems made it possible to simply move the support hardware and services largely outside the active volume of the system. For a system five meters long, that simply is not an option. The design of the STS for the SDC experiment was the result of numerous compromises between the capabilities required to do the physics and the limitations imposed by cost, material properties, and silicon strip detector characteristics. From the point of view of the physics, the silicon system should start as close to the interaction point as possible. In addition, the detectors should measure the position of particles passing through them with no errors, and should not deflect or interact with the particles in any way. However, cost, radiation damage, and other factors limiting detector performance dictated, other, more realistic values. Radiation damage limited the inner radius of the silicon detectors to about 9 cm, whereas cost limited the outer radius of the detectors to about 50 cm. Cost also limits the half length of the system to about 250 cm. To control the effects of radiation damage on the detectors required operating the system at a temperature of 0{degrees}C or below, and maintaining that temperature throughout life of the system. To summarize, the physics and properties of the silicon strip detectors requires that the detectors be operated at or below 0{degrees}C, be positioned very accurately during assembly and remain positionally stable throughout their operation, and that all materials used be radiation hard and have a large thickness for one radiation length.

  13. Experimental study of a laser-heated solenoid

    International Nuclear Information System (INIS)

    Rutkowski, H.L.

    1975-01-01

    An experimental investigation was made of the interaction of an intense CO 2 laser beam with a column of initially uv-ionized hydrogen immersed in a steady magnetic field of up to 100 kG. Under the intense laser radiation, the gas becomes ionized and heated to temperatures as high as 150 eV (1.6 x 10 6 0 K). The primary purpose of the investigation was to determine the properties of the dense, hot plasma formed in this manner. Time and space resolved measurements of the plasma electron density were made using holographic interferometry along the axis and Mach--Zehnder interferometry across the column. The temperature was determined by measuring the decay rate of a line from CV in the quartz uv. These measurements were supplemented by streak photography to provide data on the development of the luminosity of the plasma column, radially and axially, as a function of time. From these various diagnostic techniques, it was possible to determine that a density minimum is formed on-axis within a few tens of nanoseconds after initiation of the laser pulse. This effectively produces a light pipe which traps the beam, and suggests that long columns can be formed by laser irradiation. The beam energy was efficiently absorbed and plasma loss rates appeared to be those expected from classical MHD modelling. While a completely unambiguous answer as to the mode of laser discharge propagation occurring in the experiment was not obtained, the bulk of the evidence suggests a ''bleaching wave'' rather than a laser driven detonator. In summary, the experiment was successful in demonstrating the creation of dense, slender columns by laser breakdown, in support of the ''laser-heated solenoid'' fusion concept

  14. Dynamics and control of twisting bi-stable structures

    Science.gov (United States)

    Arrieta, Andres F.; van Gemmeren, Valentin; Anderson, Aaron J.; Weaver, Paul M.

    2018-02-01

    Compliance-based morphing structures have the potential to offer large shape adaptation, high stiffness and low weight, while reducing complexity, friction, and scalability problems of mechanism based systems. A promising class of structure that enables these characteristics are multi-stable structures given their ability to exhibit large deflections and rotations without the expensive need for continuous actuation, with the latter only required intermittently. Furthermore, multi-stable structures exhibit inherently fast response due to the snap-through instability governing changes between stable states, enabling rapid configuration switching between the discrete number of programmed shapes of the structure. In this paper, the design and utilisation of the inherent nonlinear dynamics of bi-stable twisting I-beam structures for actuation with low strain piezoelectric materials is presented. The I-beam structure consists of three compliant components assembled into a monolithic single element, free of moving parts, and showing large deflections between two stable states. Finite element analysis is utilised to uncover the distribution of strain across the width of the flange, guiding the choice of positioning for piezoelectric actuators. In addition, the actuation authority is maximised by calculating the generalised coupling coefficient for different positions of the piezoelectric actuators. The results obtained are employed to tailor and test I-beam designs exhibiting desired large deflection between stable states, while still enabling the activation of snap-through with the low strain piezoelectric actuators. To this end, the dynamic response of the I-beams to piezoelectric excitation is investigated, revealing that resonant excitations are insufficient to dynamically trigger snap-through. A novel bang-bang control strategy, which exploits the nonlinear dynamics of the structure successfully triggers both single and constant snap-through between the stable states

  15. Rac1 and RhoA: Networks, loops and bistability.

    Science.gov (United States)

    Nguyen, Lan K; Kholodenko, Boris N; von Kriegsheim, Alex

    2016-08-17

    Cell migration requires a precise temporal and spatial coordination of several processes which allow the cell to efficiently move. The extension and retraction of membrane protrusion, as well as adhesion are controlled by the Rho-family small GTPases. Two members of the family, Rac1 and RhoA, can show opposite behaviors and spatial localisations, with RhoA being active toward the rear of the cell and regulating its retraction during migration, whereas Rac1 is active toward the front of the cell. In addition to the spatial segregation, RhoA and Rac1 activity at the leading edge of the cells has an element of temporal segregation, with RhoA and Rac1 activities peaking at separate points during the migratory cycle of protrusion and retraction. Elements of this separation have been explained by the presence of 2 mutually inhibitory feedbacks, where Rac1 inhibits RhoA and RhoA in turn can inhibit Rac1. Recently, it was shown that Rac1 and RhoA activity and downstream signaling respond in a bistable manner to perturbations of this network.

  16. Hindrances to bistable front propagation: application to Wolbachia invasion.

    Science.gov (United States)

    Nadin, Grégoire; Strugarek, Martin; Vauchelet, Nicolas

    2018-05-01

    We study the biological situation when an invading population propagates and replaces an existing population with different characteristics. For instance, this may occur in the presence of a vertically transmitted infection causing a cytoplasmic effect similar to the Allee effect (e.g. Wolbachia in Aedes mosquitoes): the invading dynamics we model is bistable. We aim at quantifying the propagules (what does it take for an invasion to start?) and the invasive power (how far can an invading front go, and what can stop it?). We rigorously show that a heterogeneous environment inducing a strong enough population gradient can stop an invading front, which will converge in this case to a stable front. We characterize the critical population jump, and also prove the existence of unstable fronts above the stable (blocking) fronts. Being above the maximal unstable front enables an invading front to clear the obstacle and propagate further. We are particularly interested in the case of artificial Wolbachia infection, used as a tool to fight arboviruses.

  17. Nonlinear response and bistability of driven ion acoustic waves

    Science.gov (United States)

    Akbari-Moghanjoughi, M.

    2017-08-01

    The hydrodynamic model is used to obtain a generalized pseudoforce equation through which the nonlinear response of periodically driven ion acoustic waves is studied in an electron-ion plasma with isothermal and adiabatic ion fluids. The pseudotime series, corresponding to different driving frequencies, indicates that nonlinearity effects appear more strongly for smaller frequency values. The existence of extra harmonic resonances in the nonlinear amplitude spectrum is a clear indication of the interaction of an external force with harmonic components of the nonlinear ion acoustic waves. It is shown that many plasma parameters significantly and differently affect the nonlinear resonance spectrum of ion acoustic excitations. A heuristic but accurate model for the foldover effect is used which quite satisfactorily predicts the bistability of driven plasma oscillations. It is remarked that the characteristic resonance peak of isothermal ion plasma oscillations appears at lower frequencies but is stronger compared to that of adiabatic ions. Comparison of the exact numerical results for fully nonlinear and approximate (weakly nonlinear) models indicates that a weakly nonlinear model exaggerates the hysteresis and jump phenomenon for higher values of the external force amplitude.

  18. On the functional relevance of frontal cortex for passive and voluntarily controlled bistable vision.

    Science.gov (United States)

    de Graaf, Tom A; de Jong, Maartje C; Goebel, Rainer; van Ee, Raymond; Sack, Alexander T

    2011-10-01

    In bistable vision, one constant ambiguous stimulus leads to 2 alternating conscious percepts. This perceptual switching occurs spontaneously but can also be influenced through voluntary control. Neuroimaging studies have reported that frontal regions are activated during spontaneous perceptual switches, leading some researchers to suggest that frontal regions causally induce perceptual switches. But the opposite also seems possible: frontal activations may themselves be caused by spontaneous switches. Classically implicated in attentional processes, these same regions are also candidates for the origins of voluntary control over bistable vision. Here too, it remains unknown whether frontal cortex is actually functionally relevant. It is even possible that spontaneous perceptual switches and voluntarily induced switches are mediated by the same top-down mechanisms. To directly address these issues, we here induced "virtual lesions," with transcranial magnetic stimulation, in frontal, parietal, and 2 lower level visual cortices using an established ambiguous structure-from-motion stimulus. We found that dorsolateral prefrontal cortex was causally relevant for voluntary control over perceptual switches. In contrast, we failed to find any evidence for an active role of frontal cortex in passive bistable vision. Thus, it seems the same pathway used for willed top-down modulation of bistable vision is not used during passive bistable viewing.

  19. Investigation of bistable perception with the "silhouette spinner": sit still, spin the dancer with your will.

    Science.gov (United States)

    Liu, Chao-Hsuan; Tzeng, Ovid J L; Hung, Daisy L; Tseng, Philip; Juan, Chi-Hung

    2012-05-01

    Many studies have used static and non-biologically related stimuli to investigate bistable perception and found that the percept is usually dominated by their intrinsic nature with some influence of voluntary control from the viewer. Here we used a dynamic stimulus of a rotating human body, the silhouette spinner illusion, to investigate how the viewers' intentions may affect their percepts. In two experiments, we manipulated observer intention (active or passive), fixation position (body or feet), and spinning velocity (fast, medium, or slow). Our results showed that the normalized alternating rate between two bistable percepts was greater when (1) participants actively attempted to switch percepts, (2) when participants fixated at the spinner's feet rather than the body, inducing as many as 25 switches of the bistable percepts within 1 min, and (3) when they watched the spinner at high velocity. These results suggest that a dynamic biologically-bistable percept can be quickly alternated by the viewers' intention. Furthermore, the higher alternating rate in the feet condition compared to the body condition suggests a role for biological meaningfulness in determining bistable percepts, where 'biologically plausible' interpretations are favored by the visual system. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Revisiting the Lissajous figure as a tool to study bistable perception.

    Science.gov (United States)

    Weilnhammer, V A; Ludwig, K; Sterzer, P; Hesselmann, G

    2014-05-01

    During bistable vision perception spontaneously "switches" between two mutually exclusive percepts despite constant sensory input. The endogenous nature of these perceptual transitions has motivated extensive research aimed at the underlying mechanisms, since spontaneous perceptual transitions of bistable stimuli should in principle allow for a dissociation of processes related to sensory stimulation from those related to conscious perception. However, transitions from one conscious percept to another are often not instantaneous, and participants usually report a considerable amount of mixed or unclear percepts. This feature of bistable vision makes it difficult to isolate transition-related visual processes. Here, we revisited an ambiguous depth-from-motion stimulus which was first introduced to experimental psychology more than 80 years ago. This rotating Lissajous figure might prove useful in complementing other bistable stimuli, since its perceptual transitions only occur at critical stimulus configurations and are virtually instantaneous, thus facilitating the construction of a perceptually equivalent replay condition. We found that three parameters of the Lissajous figure - complexity, line width, and rotational speed - differentially modulated its perceptual dominance durations and transition probabilities, thus providing experimenters with a versatile tool to study the perceptual dynamics of bistable vision. Copyright © 2014 Elsevier B.V. All rights reserved.