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2-Dimensional studies of the disk-and-washer and side-coupled resonant cavity structures

Description: The work done consists of three parts: optimizing the disk-and-washer (DAW) structure at ..beta.. = 0.5662 corresponding to E = 200 MeV; comparing the DAW structure with the side-coupled (SCS) structure at various values of beta, ranging from ..beta.. = 0.4569 and E = 116 MeV to ..beta.. = 0.7131 and E = 400 MeV; and re-optimizing the DAW structure at ..beta.. = 0.7131. 4 refs., 51 figs., 41 tabs.
Date: December 1, 1987
Creator: Larry, L.D. Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Impedances of the shielded bellows in the SSC and the effects on beam stability

Description: The 1.08 km of bellows in Design A of the SSC will contribute to single-bunch instabilities: transverse mode-coupling, transverse microwave (for broad band at 13 GHz), and longitudinal microwave. The effectiveness of shielded bellows is considered. (GHT)
Date: July 1, 1985
Creator: Ng, King-Yuen
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Resonant impedance of bellows above cutoff

Description: The perturbation method of Chatard-Moulin and Papiernik is used to calculate the longitudinal and transverse impedances, Z(..omega..) and Z/sub perpendicular/(..omega..), of a bellows. The bellows shape is defined by its radius a(z) = a (1 + epsilons(z)), where a is the mean radius, epsilon a small parameter, and s(z) describes the convolution of the bellows. A finite wall conductivity is considered and the resonant contribution to the impedance above the cutoff frequency of the unperturbed cha… more
Date: January 1, 1980
Creator: Krinsky, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Automatic voltage-imbalance detector

Description: A device is described for indicating and preventing damage to voltage cells such as galvanic cells and fuel cells connected in series by detecting sequential voltages and comparing these voltages to adjacent voltage cells. The device is implemented by using operational amplifiers and switching circuitry is provided by transistors. The device can be utilized in battery powered electric vehicles to prevent galvanic cell damage and also in series connected fuel cells to prevent fuel cell damage.
Date: May 20, 1981
Creator: Bobbett, R. E.; McCormick, J. B. & Kerwin, W. J.
Item Type: Refine your search to only Patent
Partner: UNT Libraries Government Documents Department
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A three-gap klystron output cavity at X-band

Description: A high-power X-band klystron employing a double-gap output cavity has been operating at SLAC. Multi-gap output circuits have lower surface gradients at the interaction gaps than single-gap ones but are prone to self-oscillate due to negative loading and trapped higher-order modes. In the double-gap circuit design, considerable attention had been directed to deal with these stability problems. The performance of the present tube appears to be limited by gap breakdown and beam interception partic… more
Date: March 1, 1992
Creator: Ko, K.; Lee, T.G.; Tonegawa, S. (Stanford Linear Accelerator Center, Menlo Park, CA (United States)) & Kroll, N. (Stanford Linear Accelerator Center, Menlo Park, CA (United States) California Univ., San Diego, La Jolla, CA (United States). Dept. of Physics)
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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ac-resistance-measuring instrument

Description: An auto-ranging ac resistance measuring instrument for remote measurement of the resistance of an electrical device or circuit connected to the instrument includes a signal generator which generates an ac excitation signal for application to a load, including the device and the transmission line, a monitoring circuit which provides a digitally encoded signal representing the voltage across the load, and a microprocessor which operates under program control to provide an auto-ranging function by… more
Date: April 22, 1981
Creator: Hof, P. J.
Item Type: Refine your search to only Patent
Partner: UNT Libraries Government Documents Department
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Terawatt power division and combination using self-magnetically insulated transmission lines

Description: Self-magnetically insulated transmission lines are necessary for the efficient transport of the terawatt pulses used in electron and ion accelerators. For some applications it is desirable to divide one transmission line into two, or to combine outputs of two or more lines into one, by means of self-magnetically insulated convolutes. Tests have been made on a coaxial-to-triaxial convolute in which connections between negative inner and outer lines are made by pins passing through holes in the i… more
Date: January 1, 1980
Creator: Crow, J.T. & Peterson, G.D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Lecture 1: introduction to power conditioning systems

Description: The purpose of the course is to present an overview of the power conditioning aspects of energy transfer systems. The objective, then, is to develop an understanding and appreciation of the physical processes that govern the performance of these systems, including the role of such elements as switches, capacitors, inductors, and resistors. Secondly, to discuss where are the sources of information once a problem area has been identified. All the information will be current and state-of-the-art, … more
Date: January 1, 1980
Creator: Sarjeant, W. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Longitudinal instability in HIF beams

Description: In contrast to an electron induction accelerator, in which the particle velocity is virtually constant, the resistive and inductive components of accelerating module impedances can cause instability for an intense non-relativistic heavy ion beam accelerated in a similar structure. Since focusing requirements at the fusion pellet imply a momentum spread {approx lt}3 {times} 10{sup {minus}4} at the end of the accelerator, it is essential to understand and suppress this instability. There is also … more
Date: April 1, 1991
Creator: Smith, L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Rf impedance measurements of the various vacuum chambers for the Advanced Photon Source (APS)

Description: Coupling impedances (Z) for the 7-GeV APS storage ring have been numerically estimated. In order to confirm these calculations, measurements of the coupling impedance of various vacuum components around the main storage ring was done with a synthetic pulse technique. A section of the beam + ante-chamber, a vacuum valve and without the internal RF screen, and a photon absorber were used as a device under test (DUT) to obtain the preliminary results. The result in the frequency domain (FD) measur… more
Date: January 1, 1991
Creator: Song, J.J.; Howell, J.W.; Kustom, R.L. & Bridges, J.F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Impedance calculations for 2-D and 3-D structures and the impedance budget of 7-GeV APS (Advanced Photon Source) storage ring

Description: For the storage ring of the 7-GeV Advanced Photon Source (APS), we numerically calculate the longitudinal and the transverse coupling impedances of various kinds of two- and three-dimensional structures. It is shown that the RF cavities are the main contributors to the longitudinal impedance, whereas the transitions between the chamber and the insertion device section dominate the transverse one. Several different numerical approaches are adopted. It is argued that the broadband resonator model… more
Date: January 1, 1989
Creator: Chou, W. & Jin, Y.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Estimate of the contributions of bellows to the impedances and beam instabilities of the SSC

Description: Between sections of the vacuum chamber, bellows are needed to compensate for thermal expansion and transverse offsets. For beampipe made of stainless steel with a coefficient of linear expansion 19 x 10/sup -6///sup 0/C and a temperature variation of approx.316/sup 0/C, the allowance for bellows is approx.1.2% of the total length of the beampipe, if we assume that the bellows are 50% compressible. This implies 1.08 km of bellows for Design A of the SSC which has a circumference of 90 km. Such a… more
Date: July 1, 1985
Creator: Bisognano, J. & Ng, K. Y.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Coupling impedance of laminated magnets in the booster

Description: The magnets in the Fermilab Booster Synchrotron are laminated in order to minimize the eddy current losses and associated field distortions expected at a 15 Hz operating frequency. To further reduce the eddy current losses, the vacuum chamber is outside the magnet, hence allowing the beam induced wall currents to see the laminations directly. This note estimates the coupling impedances and beam energy loss per turn caused by the exposed laminations.
Date: July 11, 1986
Creator: Shafer, R. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Damping the transverse resistive wall instability in the AGS Booster

Description: A transverse bunch-to-bunch feedback system will be installed on the AGS Booster to suppress coherent coupled bunch oscillations driven by the resistive wall impedance of the vacuum chamber when accelerating high intensity proton beams (circulating currents > 3 amp). It is possible to estimate the expected growth rate of the instability by scaling from the machine parameters and measurements made on the AGS. An upper limit of 1.5 {times} 10{sup 3} sec{sup {minus}1} at 1.5 GeV kinetic energy wit… more
Date: January 1, 1989
Creator: Raka, E. (Brookhaven National Lab., Upton, NY (USA))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Study of collective effects in a low-emittance PEP lattice

Description: This paper summarizes the work on the collective effects studied during the previously described low-emittance operation of PEP. These studies looked at the single bunch and multi-bunch current limits consistent with stable beam operation. The lower than expected current limits and observed coherent beam oscillations, together with methods of countering them, were considered at a recent SSRL workshop. A result of these studies has been that the lower momentum compaction factor and large beta fu… more
Date: January 1, 1989
Creator: Kramer, S. L.; Borland, M.; Galayda, J.; Jackson, A.; Winick, H.; Zisman, M. S. (Argonne National Lab., IL (USA) et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Analysis of resonant longitudinal instability in a heavy ion induction linac

Description: A high current beam of subrelativistic ions accelerated in an induction linac is predicted (in some circumstances) to exhibit unstable growth of current fluctuations at high frequencies (v{approximately}100 MHz). The instability is driven by the interaction between the beam and accelerator modules at frequencies close to a cavity resonance. The extent of unstable growth depends on features of the coupling impedance, beam parameters, and total pulse and accelerator lengths. Transient and asympto… more
Date: April 1, 1991
Creator: Lee, E.P. & Smith, L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Design of a high power cross field amplifier at X band with an internally coupled waveguide

Description: Cross field amplifiers (CFA) have been used in many applications where high power, high frequency microwaves are needed. Although these tubes have been manufactured for decades, theoretical analysis of their properties is not as highly developed as for other microwave devices such as klystrons. We have developed a simulation model for CFAs using the PIC code CONDOR. Our simulations indicate that there are limits to the maximum RF field strength that a CEA can sustain. When the fields become too… more
Date: January 1, 1991
Creator: Eppley, K. & Ko, Kwok.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Impedance measurements on button electrodes

Description: In the Advanced Light Source, there will be about 400 capacitance button electrodes in the beam position monitor (BPM) system, hence the contribution of each button to the machine beam impedance must be very small. We have measured the impedance of a single button as sensed by a coax connected directly to the button surface. This method is very sensitive and did not require a model of the total beam chamber as would the usual wire method. The measurements covered the range 0.1--20 GHz. The prop… more
Date: March 1, 1989
Creator: Jacob, A. & Lambertson, G.R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Rf vacuum feedthroughs

Description: The development of rf vacuum feedthroughs is discussed. Two considerations of the development are given: impedance matching to the transmission line (measured by bandwidth) and the importance of a perpendicular orientation of the dielectric window relative to the electric fields. The report consists of 25 viewgraphs. (WRF)
Date: January 1, 1985
Creator: Raridon, R. J.; Whealton, J. H.; Bell, M. A.; Hoffman, D. J.; Baity, F. W. & Owens, T. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Influence of the synchrotron radiation on particle dynamics in a rectangular undulator

Description: This paper is concerned with the synchrotron radiation from an undulating electron beam in a rectangular waveguide. It is shown analytically and numerically that the radiated energy spectrum may differ significantly from the free space result when the undulator length divided by the Lorentz factor of the electron beam is larger than the transverse size of the waveguide. The undulator radiation is identified with the awake field in beam instabilities. The concepts of wake function and impedance … more
Date: March 1, 1989
Creator: Chin, Yong Ho
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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