L. Hendrickson

Bio: L. Hendrickson is an academic researcher from Stanford University. The author has contributed to research in topics: Control system & Communications system. The author has an hindex of 8, co-authored 13 publications receiving 161 citations.

Wire scanners for beam size and emittance measurements at the SLC

Abstract: The authors describe the design, construction, commissioning and ultimate uses of wire scanners in the SLC (SLAC Linear Collider), focusing on the linear accelerator and upstream systems scanners. Of particular interest is the interaction between the wire and the scattered radiation from the wire with the extreme electric field of the beam. As this field reaches the level of several volts/angstrom, as it does easily at the SLC interaction point (and may in upstream parts of SLC), field emission from the wire may occur. A key feature of SLC operation is the degree of high level active control required to keep it optimized. Advanced high level control software allows the use of wire scanner data in feedback and beam optimization procedures. Non-invasive scans are performed almost continually and the results are logged so that long term trends in emittance can be examined. >

Adaptive cascaded beam based feedback at the SLC

Abstract: The SLAC Linear Collider now has a total of twenty-four beam-steering feedback loops used to keep the electron and positron beams on their desired trajectories. Seven of these loops measure and control the same beam as it proceeds down the linac through the arcs to the final focus. Ideally each loop should correct only for disturbances that occur between it and the immediate upstream loop. In fact, in the original system each loop corrected for all upstream disturbances. This resulted in undesirable overcorrection and ringing. We added MIMO (Multiple Input Multiple Output) adaptive noise cancellers to separate the signal we wish to correct from disturbances further up stream. This adaptive control improved performance in the 1992 run. >

Generalized fast feedback system in the SLC

Abstract: A generalized fast feedback system has been developed to stabilize beams at various locations in the SLC. The system is designed to perform measurements and change actuator settings to control beam states such as position, angle and energy on a pulse to pulse basis. The software design is based on the state space formalism of digital control theory. The system is database-driven, facilitating the addition of new loops without requiring additional software. A communications system, KISNet, provides fast communications links between microprocessors for feedback loops which involve multiple micros. Feedback loops have been installed in seventeen locations throughout the SLC and have proven to be invaluable in stabilizing the machine.

Adaptive cascaded beam-based feedback at the SLC

Abstract: The SLAC Linear Collider now has a total of twenty-four beam-steering feedback loops used to keep the electron and positron beams on their desired trajectories. Seven of these loops measure and control the same beam as it proceeds down the linac through the arcs to the final focus. Ideally each loop should correct only for disturbances that occur between it and the immediate upstream loop. In fact, in the original system each loop corrected for all upstream disturbances. This resulted in undesirable overcorrection and ringing. We added MIMO (Multiple Input Multiple Output) adaptive noise cancellers to separate the signal we wish to correct from disturbances further up stream. This adaptive control improved performance in the 1992 run. >

Use of digital control theory state space formalism for feedback at SLC

Abstract: The algorithms used in the database-driven SLC fast-feedback system are based on the state-space formalism of digital control theory. These are implemented as a set of matrix equations which use a Kalman filter to estimate a vector of states from a vector of measurements and then apply a gain matrix to determine the actuator settings from the state vector. The matrices used in the calculation are derived offline using linear quadratic Gaussian minimization. For a given noise spectrum, this procedure minimizes the RMS of the states (e.g., the position or energy of the beam). The offline program also allows simulation of the loop's response to arbitrary inputs and calculates its frequency response. >

Digital control of dynamic systems

Abstract: Digital Control Of Dynamic Systems This well-respected, market-leading text discusses the use of digital computers in the real-time control of dynamic systems. The emphasis is on the design of digital controls that achieve good dynamic response and small errors while using signals that are sampled in time and quantized in amplitude. Digital Control of Dynamic Systems (3rd Edition): Franklin ... This well-respected, market-leading text discusses the use of digital computers in the real-time control of dynamic systems. The emphasis is on the design of digital controls that achieve good dynamic response and small errors while using signals that are sampled in time and quantized in amplitude. Digital Control of Dynamic Systems: Gene F. Franklin ... Digital Control of Dynamic Systems, 2nd Edition. Gene F. Franklin, Stanford University. J. David Powell, Stanford University Digital Control of Dynamic Systems, 2nd Edition Pearson This well-respected work discusses the use of digital computers in the real-time control of dynamic systems. The emphasis is on the design of digital controls that achieve good dynamic response and small errors while using signals that are sampled in time and quantized in amplitude. MATLAB statements and problems are thoroughly and carefully integrated throughout the book to offer readers a complete design picture. Digital Control of Dynamic Systems, 3rd Edition ... Digital control of dynamic systems | Gene F. Franklin, J. David Powell, Michael L. Workman | download | B–OK. Download books for free. Find books Digital control of dynamic systems | Gene F. Franklin, J ... Abstract This well-respected work discusses the use of digital computers in the real-time control of dynamic systems. The emphasis is on the design of digital controls that achieve good dynamic... (PDF) Digital Control of Dynamic Systems Digital Control of Dynamic Systems, Addison.pdf There is document Digital Control of Dynamic Systems, Addison.pdfavailable here for reading and downloading. Use the download button below or simple online reader. The file extension PDFand ranks to the Documentscategory. Digital Control of Dynamic Systems, Addison.pdf Download ... Automatic control is the science that develops techniques to steer, guide, control dynamic systems. These systems are built by humans and must perform a specific task. Examples of such dynamic systems are found in biology, physics, robotics, finance, etc. Digital Control means that the control laws are implemented in a digital device, such as a microcontroller or a microprocessor. Introduction to Digital Control of Dynamic Systems And ... The discussions are clear, nomenclature is not hard to follow and there are plenty of worked examples. The book covers discretization effects and design by emulation (i.e. design of continuous-time control system followed by discretization before implementation) which are not to be found on every book on digital control. Amazon.com: Customer reviews: Digital Control of Dynamic ... Find helpful customer reviews and review ratings for Digital Control of Dynamic Systems (3rd Edition) at Amazon.com. Read honest and unbiased product reviews from our users. Amazon.com: Customer reviews: Digital Control of Dynamic ... 1.1.2 Digital control Digital control systems employ a computer as a fundamental component in the controller. The computer typically receives a measurement of the controlled variable, also often receives the reference input, and produces its output using an algorithm. Introduction to Applied Digital Control From the Back Cover This well-respected, marketleading text discusses the use of digital computers in the real-time control of dynamic systems. The emphasis is on the design of digital controls that achieve good dynamic response and small errors while using signals that are sampled in time and quantized in amplitude. Digital Control of Dynamic Systems (3rd Edition) Test Bank `Among the advantages of digital logic for control are the increased flexibility `of the control programs and the decision-making or logic capability of digital `systems, which can be combined with the dynamic control function to meet `other system requirements. `The digital controls studied in this book are for closed-loop (feedback) Every day, eBookDaily adds three new free Kindle books to several different genres, such as Nonfiction, Business & Investing, Mystery & Thriller, Romance, Teens & Young Adult, Children's Books, and others.

A 2 to 4 nm high power FEL on the SLAC linac

Abstract: We report the results of preliminary studies of a 2 to 4 nm SASE FEL, using a photoinjector to produce the electron beam, and the SLAC linac to accelerate it to an energy up to 10 GeV. Longitudinal bunch compression is used to increase ten fold the peak current to 2.5 kA, while reducing the bunch length to the subpicosecond range. The saturated output power is in the multi-gigawatt range, producing about 1014 coherent photons within a bandwidth of about 0.2% rms, in a pulse of several millijoules. At 120 Hz repetition rate the average power is about 1 W. The system is optimized for X-ray microscopy in the water window around 2 to 4 nm, and will permit imaging a biological sample in a single subpicosecond pulse.

Wire scanners for beam size and emittance measurements at the SLC

Abstract: The authors describe the design, construction, commissioning and ultimate uses of wire scanners in the SLC (SLAC Linear Collider), focusing on the linear accelerator and upstream systems scanners. Of particular interest is the interaction between the wire and the scattered radiation from the wire with the extreme electric field of the beam. As this field reaches the level of several volts/angstrom, as it does easily at the SLC interaction point (and may in upstream parts of SLC), field emission from the wire may occur. A key feature of SLC operation is the degree of high level active control required to keep it optimized. Advanced high level control software allows the use of wire scanner data in feedback and beam optimization procedures. Non-invasive scans are performed almost continually and the results are logged so that long term trends in emittance can be examined. >

Beam diagnostics for accelerators

Abstract: This introductory course aims at a reasonably complete coverage of beam diagnostic devices used in linear and circular accelerators and in primary beam lines. The weight is on the concepts and the indication of variants, while for technical details the reader is referred to the literature. The present updated version replaces those from previous General Accelerator Physics Courses.

A laser-based beam profile monitor for the SLC/SLD interaction region

Abstract: Beam size estimates made using beam-beam deflections are used for optimization of the Stanford Linear Collider (SLC) electron-positron beam sizes. Typical beam sizes and intensities expected for 1996 operations are 2.1 × 0.6 μm (x, y) at 4.0 × 1010 particles per pulse. Conventional profile monitors, such as scanning wires, fail at charge densities well below this. The laser-based profile monitor uses a finely-focused 350-nm wavelength tripled YLF laser pulse that traverses the particle beam path about 29 cm away from the e+/e− IP. Compton scattered photons and degraded e+/e− are detected as the beam is steered across the laser pulse. The laser pulse has a transverse size of 380 nm and a Rayleigh range of about 5 μm.