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Main Injector synchronous timing system

Description: The Synchronous Timing System is designed to provide sub-nanosecond timing to instrumen-tation during the acceleration of particles in the Main Injector. Increased energy of the beam particles leads to a small but significant increase in speed, reducing the time it takes to com-plete a full turn of the ring by 61 nanoseconds (or more than 3 RF buckets). In contrast, the reference signal, used to trigger instrumentation and transmitted over a cable, has a constant group delay. This difference leads to a phase slip during the ramp and prevents instrumentation such as dampers from properly operating without additional measures. The Synchronous Tim-ing System corrects for this phase slip as well as signal propagation time changes due to tem-perature variations. A module at the LLRF system uses a 1.2 Gbit/s G-Link chip to transmit the RF clock and digital data (e.g. the current frequency) over a single mode fiber around the ring. Fiber optic couplers at service buildings split off part of this signal for a local module which reconstructs a synchronous beam reference signal. This paper describes the background, design, and expected performance of the Synchronous Timing System.
Date: March 2, 1999
Creator: Steimel, Willem Blokland and James
Partner: UNT Libraries Government Documents Department

Upgrade of NSLS timing system

Description: We report on the progress of the new NSLS timing system. There are three types of requirements for NSLS timing system: clocks, synchronization and trigger circuits. All ring revolution frequency clocks are generated using ECL and high speed TTL logic. The synchronization circuits allows to fill both storage rings with any bunch pattern. The triggers are generated by using commercially available digital delay generators. The delay unit`s outputs are ultrastable, with a resolution of 5 ps, and are programmed by computer via IEEE 488 interface. The block diagrams, description of all major timing components and the present status are provided in this paper.
Date: May 1, 1995
Creator: Singh, O.; Ramamoorthy, S.; Sheehan, J. & Smith, J.
Partner: UNT Libraries Government Documents Department

Timer modules for radiation detection systems

Description: In developing radiation detection instrumentation at Rocky Flats, a system concept using plug-in modules was planned. Losses of operational time due to maintenance are drastically reduced as a malfunctioning module can be replaced within minutes. Versatility is another advantage of the modular concept and a particular module can be used in many different system designs. A significant cost savings in system development can also be realized. Two of the timers described are housed in two-wide Nuclear Instrumentation Bin (NIM-BIN) modules and a third model in a one-wide NIM-BIN module. The design uses the latest COS/ MOS (complimentary symmetry metal-oxide semiconductor) integrated circuitry, featuring low power, low cost, and high reliability. These modules were developed specifically for radiation detection systems. Model 24370-21 is used in gross alpha detection systems. Model 27213-21 appears in a medical wound- counter system and the third, Model 27213-23, operates in a gamma spectrometer system. These modules can have application in other related systems as well. Operational procedures and servicing are included. (auth)
Date: March 29, 1974
Creator: Martin, B. E.
Partner: UNT Libraries Government Documents Department

A Dual Triangle Timing Circuit for Improved Performance of 4-Quadrant H-Bridge Switches

Description: Fermilab is in the process of upgrading its Booster Correction Element System to include full field correction element magnets to correct position and chromaticity throughout the booster cycle. This upgrade requires power supplies with maximum outputs of {+-}180V/{+-}65A, with current bandwidths of 5k Hz and with slew rates of min to max current in 1ms. For seamless operation around zero current and voltage, we use continuous switching on both sides of the bridge. Although the straightforward way of coordinating the switching on both sides of the bridge can be accomplished with one triangle timing wave and one voltage reference, we have found that using two triangle waves yields a switching coordination that effectively doubles the frequency of the differential ripple on the load and allows for better filtering of the output ripple.
Date: May 1, 2009
Creator: Krafczyk, G.; Jensen, C.; Pfeffer, H.; Warchol, G. & /Fermilab
Partner: UNT Libraries Government Documents Department

Weighting mean timers for high energy physics electronics

Description: A new family of electronics circuits, weighting mean timer, is presented in this technical memo. Weighting mean timers can be used in high energy physics experiment electronics to implement the \concurrence" condition in hardware trigger stage. Several possible architectures of weighting mean timers have been discussed.
Date: November 1, 1998
Creator: Wu, J.
Partner: UNT Libraries Government Documents Department

A bunch clock for the Advanced Photon Source

Description: A bunch clock timing module has been developed for use by Advanced Photon Source beamlines. The module provides bunch pattern and timing information that can be used to trigger beamline data collection equipment. The module is fully integrated into the control system software (EPICS) which automatically loads it with the storage ring fill pattern at injection time. Fast timing outputs (1 ns FWHM) for each stored bunch are generated using the storage ring low-level rf and revolution clock as input references. Fiber-optic-based transmitters and receivers are used to transmit a 352-MHz low-level rf reference to distributed bunch clock modules. The bunch clock module is a single-width VME module and may be installed in a VME crate located near beamline instrumentation. A prototype has been in use on the SRI CAT beamline for over a year. The design and integration into the control system timing software along with measured performance results are presented.
Date: June 1, 1997
Creator: Lenkszus, F.R. & Laird, R.J.
Partner: UNT Libraries Government Documents Department

Los Alamos Neutron Science Center (LANSCE) accelerator timing system upgrade

Description: The Los Alamos Neutron Science Center (LANSCE) 800 MeV proton linear accelerator (linac) operates at a maximum repetition rate of twice the AC power line frequency, i.e. 120 Hz. The start of each machine cycle occurs a fixed delay after each zero-crossing of the AC line voltage. Fluctuations in the AC line frequency and phase are therefore present on all linac timing signals. Proper beam acceleration along the linac requires that the timing signals remain well synchronized to the AC line. For neutron chopper spectrometers, e.g., PHAROS at the Manuel Lujan Jr. Neutron Scattering Center, accurate neutron energy selection requires that precise synchronization be maintained between the beam-on-target arrival time and the neutron chopper rotor position. This is most easily accomplished when the chopper is synchronized to a stable, fixed frequency signal. A new zero-crossing circuit which employs a Phase-Locked Loop (PLL) has been developed to increase the phase and frequency stability of the linac timing signals and thereby improve neutron chopper performance while simultaneously maintaining proper linac operation. Results of timing signal data analysis and modeling and a description of the PLL circuit are presented.
Date: October 1, 1997
Creator: Rybarcyk, L.J. & Shelley, F.E. Jr.
Partner: UNT Libraries Government Documents Department

National Ignition Facility sub-system design requirements integrated timing system SSDR 1.5.3

Description: This System Design Requirement document establishes the performance, design, development, and test requirements for the Integrated Timing System, WBS 1.5.3 which is part of the NIF Integrated Computer Control System (ICCS). The Integrated Timing System provides all temporally-critical hardware triggers to components and equipment in other NIF systems.
Date: August 26, 1996
Creator: Wiedwald, J.; Van Aersau, P. & Bliss, E.
Partner: UNT Libraries Government Documents Department

Method and apparatus for detecting timing errors in a system oscillator

Description: This invention is comprised of a method of detecting timing errors in a system oscillator for an electronic device, such as a power supply, includes the step of comparing a system oscillator signal with a delayed generated signal and generating a signal representative of the timing error when the system oscillator signal is not identical to the delayed signal. An LED indicates to an operator that a timing error has occurred. A hardware circuit implements the above-identified method.
Date: December 31, 1991
Creator: Gliebe, R.J. & Kramer, W.R.
Partner: UNT Libraries Government Documents Department

Modified Noise Power Ratio testing of high resolution digitizers

Description: A broadband, full signal range, side-by-side (tandem) test method for estimating the internal noise performance of high resolution digitizers is described and illustrated. The technique involves a re-definition of the traditional Noise Power Ratio (NPR) test, a change that not only makes this test applicable to higher resolution systems than was previously practical, but also enhances its value and flexibility. Since coherence analysis is the basis of this new definition, and since the application of coherence procedures to high resolution data poses several problems, this report discusses these problems and their resolution.
Date: May 1, 1994
Creator: McDonald, T. S.
Partner: UNT Libraries Government Documents Department

The Advanced Photon Source event system

Description: The Advanced Photon Source, like many other facilities, requires a means of transmitting timing information to distributed control system 1/0 controllers. The APS event system provides the means of distributing medium resolution/accuracy timing events throughout the facility. It consists of VME event generators and event receivers which are interconnected with 10OMbit/sec fiber optic links at distances of up to 650m in either a star or a daisy chain configuration. The systems event throughput rate is 1OMevents/sec with a peak-to-peak timing jitter down to lOOns depending on the source of the event. It is integrated into the EPICS-based A.PS control system through record and device support. Event generators broadcast timing events over fiber optic links to event receivers which are programmed to decode specific events. Event generators generate events in response to external inputs, from internal programmable event sequence RAMS, and from VME bus writes. The event receivers can be programmed to generate both pulse and set/reset level outputs to synchronize hardware, and to generate interrupts to initiate EPICS record processing. In addition, each event receiver contains a time stamp counter which is used to provide synchronized time stamps to EPICS records.
Date: December 31, 1995
Creator: Lenkszus, F.R. & Laird, R.
Partner: UNT Libraries Government Documents Department

The future of GPS-based electric power system measurements, operation and control

Description: Much of modern society is powered by inexpensive and reliable electricity delivered by a complex and elaborate electric power network. Electrical utilities are currently using the Global Positioning System-NAVSTAR (GPS) timekeeping to improve the network`s reliability. Currently, GPS synchronizes the clocks on dynamic recorders and aids in post-mortem analysis of network disturbances. Two major projects have demonstrated the use of GPS-synchronized power system measurements. In 1992, the Electric Power Research Institute`s (EPRI) sponsored Phase Measurements Project used a commercially available Phasor Measurements Unit (PMU) to collect GPS-synchronized measurements for analyzing power system problems. In 1995, Bonneville Power Administration (BPA) and Western Area Power Administration (WAPA) under DOE`s and EPRI`s sponsorship launched the Wide Area Measurements (WAMS) project. WAMS demonstrated GPS-synchronized measurements over a large area of their power networks and demonstrated the networking of GPS-based measurement systems in BPA and WAPA. The phasor measurement technology has also been used to conduct dynamic power system tests. During these tests, a large dynamic resistor was inserted to simulate a small power system disturbance.
Date: November 1, 1998
Creator: Rizy, D. T.; Wilson, R. E.; Martin, K. E.; Litzenberger, W. H.; Hauer, J. F.; Overholt, P. N. et al.
Partner: UNT Libraries Government Documents Department

Ultrasonic Sensor and Method of use

Description: An ultrasonic sensor system and method of use for measuring transit time through a liquid sample, comprising at least one ultrasonic transducer coupled to a precision time interval counter. The timing circuit captures changes in transit time, representing small changes in the velocity of sound transmitted, over necessarily small time intervals (nanoseconds) and uses the transit time changes to identify the presence of non-conforming constituents in the sample.
Date: July 22, 1999
Creator: Condreva, Kenneth J.
Partner: UNT Libraries Government Documents Department

The Timing Synchronization System At Jefferson Lab

Description: This paper will present the requirements and design of the Timing Synchronization System for the Continuous Electron Beam Accelerator Facility control system at Thomas Jefferson National Accelerator Facility. A clock module has been designed to reside in a VME crate with a master front-end computer and communicate with the Data Acquisition VME crates and their front-end computers via a serial fiber optic line. Configuration of the clock modules is jumper and software selectable. The application that motivated the development of the Timing Synchronization System, the Accelerator 30 Hz System, will also be presented. This system needs less than 1ms time differential between the data acquisitions on the various DAQ front-end computers in order to gather correlated information. The development of and our operational experience with this application using the new timing synchronization system will be discussed. *This work was supported by the U.S. DOE contract No. DE-AC05-84-ER40150
Date: November 1, 2001
Creator: Keesee, Marie; Dickson, Richard; Flood, Roger & Lebedev, Valeri
Partner: UNT Libraries Government Documents Department

PEP-II injection timing and controls

Description: Hardware has been built and software written and incorporated in the existing SLC accelerator control system to control injection of beam pulses from the accelerator into the PEP-II storage rings currently under construction. Hardware includes a CAMAC module to delay the machine timing fiducial in order that a beam pulse extracted from a damping ring will be injected into a selected group of four 476 MHz buckets in a PEP-II ring. Further timing control is accomplished by shifting the phase of the bunches stored in the damping rings before extraction while leaving the phase of the PEP-II stored beam unchanged. The software which drives timing devices on a pulse-to-pulse basis relies on a dedicated communication link on which one scheduling microprocessor broadcasts a 128-bit message to all distributed control microprocessors at 360 Hz. PEP-II injection will be driven by the scheduling microprocessor according to lists specifying bucket numbers in arbitrary order, and according to scheduling constraints maximizing the useful beam delivered to the SLC collider currently in operation. These lists will be generated by a microprocessor monitoring the current stored per bucket in each of the PEP-II rings.
Date: July 1997
Creator: Bharadwaj, V.; Browne, M.; Crane, M.; Gromme, T.; Himel, T.; Ross, M. et al.
Partner: UNT Libraries Government Documents Department

Low power RF beam control electronics for the LEB

Description: Beam Control Electronics for the Low Energy Booster (LEB) should provide a fine reference phase and frequency for the High Power RF System. Corrections applied on the frequency of the rf signal will reduce dipole synchrotron oscillations due to power supply regulation errors, errors in frequency source or errors in the cavity voltage. It will allow programmed beam radial position control throughout the LEB acceleration cycle. Furthermore the rf signal provides necessary connections during, adiabatic capture of the beam as injected into the LEB by the Linac and will guarantee LEB rf phase synchronism with the Medium Energy Booster (MEB) rf at a programmed time in the LEB cycle between a unique LEB bucket and a unique MEB bucket. We show in this paper a design and possible interfaces with other subsystems of the LEB such as the beam instrumentation, High Power RF Stations, global accelerator controls and the precision timing system. The outline of various components of the beam control system is also presented followed by some test results.
Date: May 1, 1993
Creator: Mestha, L.K.; Mangino, J.; Brouk, V.; Uher, T. & Webber, R.C.
Partner: UNT Libraries Government Documents Department

Multichannel interval timer

Description: A CAMAC based modular multichannel interval timer is described. The timer comprises twelve high resolution time digitizers with a common start enabling twelve independent stop inputs. Ten time ranges from 2.5 ..mu..s to 1.3 ..mu..s can be preset. Time can be read out in twelve 24-bit words either via CAMAC Crate Controller or an external FIFO register. LSB time calibration is 78.125 ps. An additional word reads out the operational status of twelve stop channels. The system consists of two modules. The analog module contains a reference clock and 13 analog time stretchers. The digital module contains counters, logic and interface circuits. The timer has an excellent differential linearity, thermal stability and crosstalk free performance.
Date: October 1, 1983
Creator: Turko, B.T.
Partner: UNT Libraries Government Documents Department

Burst mode FEL with the ETA-III induction linac

Description: Pulses of 140 GHz microwaves have been produced at a 2 kHz rate using the ETA-III induction linac and IMP wiggler. The accelerator was run in bursts of up to 50 pulses at 6 MeV and greater than 2 kA peak current. A feedback timing control system was used to synchronize acceleration voltage pulses with the electron beam, resulting in sufficient reduction of the corkscrew and energy sweep for efficient FEL operation. Peak microwave power for short bursts was in the range 0.5--1.1 GW, which is comparable to the single-pulse peak power of 0.75--2 GW. FEL bursts of more than 25 pulses were obtained.
Date: May 13, 1993
Creator: Lasnier, C. J.; Allen, S. L. & Felker, B.
Partner: UNT Libraries Government Documents Department

Optical timing receiver for the NASA laser ranging system. Part I. Constant-fraction discriminator

Description: Position-resolution capabilities of the NASA laser ranging system are essentially determined by time-resolution capabilities of its optical timing receiver. The optical timing receiver consists of a fast photoelectric device, primarily a standard of microchannel-plate-type photomultiplier or an avalanche photodiode detector, a timing discriminator, a high-precision time-interval digitizer, and a signal-processing system. The time-resolution capabilities of the receiver are determined by the photoelectron time spread of the photoelectric device, the time walk and resolution characteristics of the timing discriminator, and the time-interval digitizer. It is thus necessary to evaluate available fast photoelectronic devices with respect to their time-resolution capabilities, and to design a very low time walk timing discriminator and a high-precision time digitizer which will be used in the laser ranging system receiver. (auth)
Date: August 14, 1975
Creator: Leskovar, B. & Lo, C.C.
Partner: UNT Libraries Government Documents Department

A CMOS delay locked loop and sub-nanosecond time-to-digital converter chip

Description: Many high energy physics and nuclear science applications require sub-nanosecond time resolution measurements over many thousands of detector channels. Phase-locked loops have been employed in the past to obtain accurate time references for these measurements. An alternative solution, based on a delay-locked loop (DLL) is described. This solution allows for a very high level of integration yet still offers resolution in the sub-nanosecond regime. Two variations on this solution are outlined. A novel phase detector, based on the Muller C element, is used to implement a charge pump where the injected charge approaches zero as the loop approaches lock on the leading edge of an input clock reference. This greatly reduces timing jitter. In the second variation the loop locks to both the leading and trailing clock edges. In this second implementation, software coded layout generators are used to automatically layout a highly integrated, multi-channel, time to digital converter (TDC). Complex clock generation can be, achieved by taking symmetric taps off the delay elements. The two circuits, DLL and TDC, were implemented in a CMOS 1.2{mu}m and 0.8{mu}m technology, respectively. Test results show a timing jitter of less than 35 ps for the DLL circuit and better solution for the TDC circuit.
Date: December 1, 1995
Creator: Santos, D.M.; Dow, S.F. & Levi, M.E.
Partner: UNT Libraries Government Documents Department