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Component development for X-band above 100 MW

Description: The requirement for some of the components described in this paper began with the Relativistic Klystron program done in collaboration with LLNL and LBL. This effort culminated in a klystron operating at 11.4 GHz delivering 330 MW into a pair of high-gradient accelerating structures. The electron beam for this klystron was formed in a 1 MeV induction linac at a very low duty cycle. The subsequent RF source development work at SLAC for the Next Linear Collider utilized some of these components, a… more
Date: May 1, 1991
Creator: Fowkes, W. R.; Callin, R. S. & Studzinski, M.
Partner: UNT Libraries Government Documents Department
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Perspectives on large linear colliders

Description: Three main items in the design of large linear colliders are presented. The first is the interrelation of energy and luminosity requirements. These two items impose severe constraints on the accelerator builder who must design a machine to meet the needs of experimentl high energy physics rather than designing a machine for its own sake. An introduction is also given for linear collider design, concentrating on what goes on at the collision point, for still another constraint comes here from th… more
Date: November 1, 1987
Creator: Richter, B.
Partner: UNT Libraries Government Documents Department
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Experimental challenges at linear colliders

Description: Experience with the operation of detectors at the SLC, and challenges to experimentation at future linear colliders are discussed.
Date: March 1, 1992
Creator: Burke, D.L.
Partner: UNT Libraries Government Documents Department
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General properties of an asymmetric B-factory lattice

Description: Scaling laws consistent with general rules of optimization have been established for colliders of unequal beams. They are valid for any ring deduced from the circular shape by insertion of straight sections. The constraint on the synchrotron motion seems to be met more easily for the head on configuration than for a finite crossing angle. In any case, the equal damping decrement requirement leads to the use of high field dipoles in the low energy ring. If the rules on equal beam size and equal … more
Date: April 1, 1989
Creator: Autin, B.
Partner: UNT Libraries Government Documents Department
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Hunting and identifying new gauge bosons at the NLC

Description: We examine the ability of the NLC ({radical}{bar s} = 500 GeV) e{sup +}e{sup {minus}} linear collider to discover and identify the origin of new neutral gauge bosons, with masses in excess of the machine's center of mass energy, via deviations from the predictions of the Standard Model for the process e{sup +}e{sup {minus}} {yields} {bar f}f. New gauge bosons with masses in the few TeV regime may be probed at such at collider. 7 refs., 3 figs., 2 tabs.
Date: October 1, 1991
Creator: Hewett, J. L. & Rizzo, T. G.
Partner: UNT Libraries Government Documents Department
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High brightness sources for colliders

Description: Different possible sources are considered and the importance of the gun for linear colliders discussed. Low emittance electron guns suitable for SLC are available now and we discuss current work that could also provide high polarization. The relative merits of {rvec {gamma}}, {rvec e}{sup {plus minus}} and {rvec p}{sup {plus minus}} are discussed and how the next linear collider (NLC) naturally provides both {rvec e}{sup {plus minus}} and {rvec {gamma}}. Particular emphasis was placed on stabil… more
Date: May 1, 1991
Creator: Spencer, J.E.
Partner: UNT Libraries Government Documents Department
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Wakefield measurements of SLAC linac structures at the Argonne AATF

Description: Damped and detuned linac structures designed to minimize the effects of wakefields excited by e{sup {plus minus}} bunch trains in future linear colliders are presently under investigation at SLAC. This paper describes the results of measurements of both longitudinal and transverse wakefields performed at the ANL Advanced Accelerator Test Facility with two SLAC-built X-Band disk-loaded waveguides: a conventional 30-cavity long constant-impedance structure and a non-conventional 50-cavity long st… more
Date: May 1, 1991
Creator: Wang, J.W.; Loew, G.A. (Stanford Linear Accelerator Center, Menlo Park, CA (USA)); Simpson, J.; Chojnacki, E.; Gai, W.; Konecny, R. et al.
Partner: UNT Libraries Government Documents Department
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Physics of a high luminosity collider operated near charm and tau pair thresholds

Description: The current plans for a high luminosity e/sup +/e/sup /minus// collider between 3.0 and 4.4 GeV/c/sup 2/ are described. Such a dedicated facility (The Tau-Charm Factory), operating near tau-pair and charm thresholds would allow studies of the decay of the third generation tau-lepton and the second generation c-quark with unprecedented precision and control of systematics. The charm physics of such a facility is discussed. 24 refs., 4 figs., 7 tabs.
Date: June 1, 1989
Creator: Schindler, R. H.
Partner: UNT Libraries Government Documents Department
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The final focus test beam project

Description: An overview is given of the Final Focus Test Beam (FFTB) that is being constructed as a prototype final focus system for a future electron-positron linear collider. This beam line will use as input the 50 GeV electron beam from the SLC linac, and is designed to reduce the transverse dimensions of the beam spot at the focal point to 1 {mu}m. 5 refs., 2 figs., 1 tab.
Date: May 1, 1991
Creator: Burke, D.
Partner: UNT Libraries Government Documents Department
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Research at SLAC on future linear colliders

Description: This paper discusses current thinking at SLAC concerning the design of a newer collider that will have a luminosity on the order of 10/sup 33/ cm/sup -2/ s/sup -1/ and a beamstrahlung energy loss on the order of .3. 13 refs., 1 fig., 1 tab. (LSP)
Date: October 1, 1987
Creator: Wilson, Perry B.
Partner: UNT Libraries Government Documents Department
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A perspective on future accelerators

Description: Some of the physics and technical issues are discussed which must be resolved before a future linear collider can be built. These issues include the center of mass energy and luminosity required for research in the range desired, length and power requirements, and cost. It is proposed that research and development of such a machine should be done internationally. (LEW)
Date: October 1, 1987
Creator: Richter, B.
Partner: UNT Libraries Government Documents Department
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Positrons for linear colliders

Description: The requirements of a positron source for a linear collider are briefly reviewed, followed by methods of positron production and production of photons by electromagnetic cascade showers. Cross sections for the electromagnetic cascade shower processes of positron-electron pair production and Compton scattering are compared. A program used for Monte Carlo analysis of electromagnetic cascades is briefly discussed, and positron distributions obtained from several runs of the program are discussed. … more
Date: November 1, 1987
Creator: Ecklund, S.
Partner: UNT Libraries Government Documents Department
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A high power cross-field amplifier at X-Band

Description: A high power cross-field amplifier is under development at SLAC with the objective of providing sufficient peak power to feed a section of an X-Band (11.424 GHz) accelerator without the need for pulse compression. The CFA being designed employs a conventional distributed secondary emission cathode but a novel anode structure which consists of an array of vane resonators alternatively coupled to a rectangular waveguide. The waveguide impedance (width) is tapered linearly from input to output so … more
Date: May 1, 1991
Creator: Eppley, K.; Feinstein, J.; Ko, K.; Kroll, N.; Lee, T. & Nelson, E.
Partner: UNT Libraries Government Documents Department
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Final focus systems for linear colliders

Description: The final focus system of a linear collider must perform two primary functions, it must focus the two opposing beams so that their transverse dimensions at the interaction point are small enough to yield acceptable luminosity, and it must steer the beams together to maintain collisions. In addition, the final focus system must transport the outgoing beams to a location where they can be recycled or safely dumped. Elementary optical considerations for linear collider final focus systems are disc… more
Date: November 1, 1987
Creator: Erickson, R.A.
Partner: UNT Libraries Government Documents Department
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Channeling crystals for positron production

Description: Particles traversing at small angles along a single crystal axis experience a collective scattering force of many crystal atoms. The enormous fields can trap the particles along an axis or plane, called channeling. High energy electrons are attracted by the positive nuclei and therefore produce strongly enhanced so called coherent bremsstrahlung and pair production. These effects could be used in a positron production target: A single tungsten crystal is oriented to the incident electron beam w… more
Date: May 1, 1991
Creator: Decker, F.J.
Partner: UNT Libraries Government Documents Department
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Simulations on pair creation from beam-beam interaction in linear colliders

Description: It has been recognized that e{sup +}e{sup {minus}} pair creation during the collision of intense beams in linear colliders will cause potential background problems for high energy experiments. Detailed knowledge of the angular-momentum spectrum of these low energy pairs is essential to the design of the interaction region. In this paper, we modify the computer code ABEL (Analysis of Beam-beam Effects in Linear colliders) to include the pair creation processes, using the equivalent photon approx… more
Date: May 1, 1991
Creator: Chen, P.; Tauchi, T. (Stanford Linear Accelerator Center, Menlo Park, CA (USA)) & Yokoya, K. (National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan))
Partner: UNT Libraries Government Documents Department
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Simulation of accelerating structures with large staggered tuning

Description: One idea for controlling multibunch beam breakup in future linear colliders is to use accelerating structures that have a large ({approximately}10%) staggered tuning, that is, a large cell-to-cell spread in frequencies of the transverse dipole modes. Simulations of such structures using the programs TBCI and LINACBBU are compared, and issues relevant to the design and optimization of such structures, such as choice of cell frequency distribution and role of cell-to-cell coupling are discussed. … more
Date: May 1, 1991
Creator: Thompson, K.A. & Wang, J.W.
Partner: UNT Libraries Government Documents Department
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Choice of parameters for linear colliders in multi-bunch mode

Description: The energy efficiency of a linear collider in multi-bunch mode is calculated for the case that the bunches in each of the two interacting beams are identical in all interaction points, a configuration which can be realized by taking advantage of the beam-beam effect between beams of opposite electric charge. The maximization of the efficiency is discussed, the maximum appears to increase nearly linearly with beam brightness and accelerating gradient, and about quadratically with the length of t… more
Date: January 1, 1987
Creator: Claus, J.
Partner: UNT Libraries Government Documents Department
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From the SLAC linear collider to the next linear collider: A status report and road map

Description: In this presentation, I will review what we have learned about linear colliders, the problems that have been uncovered, and the technology-development program aimed at realizing the next high energy machine. I will then close with a few comments on how to get on with the job of building it.
Date: February 1, 1992
Creator: Richter, B.
Partner: UNT Libraries Government Documents Department
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Phase control of the microwave radiation in free electron laser two-beam accelerator

Description: A phase control system for the FEL portion of Two-Beam Accelerator is proposed. The control keeps the phase error within acceptable bounds. The control mechanism is analyzed, both analytically in a ''resonant particle'' approximation and numerically in a multi-particle simulation code. Sensitivity of phase errors to the FEL parameters has been noticed.
Date: July 1, 1987
Creator: Goren, Y. & Sessler, A. M.
Partner: UNT Libraries Government Documents Department
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Beam-based alignment and tuning procedures for e sup + e sup minus collider final focus systems

Description: For future linear colliders, with very small emittances and beam sizes and demanding tolerances on final focus system alignment and magnet errors, it becomes increasingly important to use the beam as a diagnostic tool. We report here procedures we have identified and will be implemented in the Final Focus Test Beam at SLAC incorporating (1) quadrupole strength changes, (2) central orbit modifications, (3) spot size measurements, and (4) beam stability monitoring. 3 refs., 4 figs., 3 tabs.
Date: May 1, 1991
Creator: Bulos, F.; Burke, D.; Helm, R.; Irwin, J.; Odian, A.; Roy, G. et al.
Partner: UNT Libraries Government Documents Department
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Electron energy spectrum and maximum disruption angle under multi-photon beamstrahlung

Description: The final electron energy spectrum under multi-photon beamstrahlung process is derived analytically in the classical and the intermediate regimes. The maximum disruption angle from the low energy tail of the spectrum is also estimated. The results are then applied to the TLC and the CLIC parameters. 6 refs., 1 fig., 1 tab.
Date: March 1, 1989
Creator: Yokoya, Kaoru & Chen, Pisin
Partner: UNT Libraries Government Documents Department
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The optics of the Final Focus Test Beam

Description: The Final Focus Test Beam (FFTB), currently under construction at the end of the SLAC Linac, is being built by an international collaboration as a test bed for ideas and methods required in the design and construction of final focus systems for next generation e{sup +}e{sup {minus}} linear colliders. The FFTB lattice is based on the previously developed principle of using sextupole pairs in a dispersive region to compensate chromaticity. The linear lattice was optimized for length, and implemen… more
Date: May 1, 1991
Creator: Irwin, J.; Brown, K.; Bulos, F.; Burke, D.; Helm, R.; Roy, G. et al.
Partner: UNT Libraries Government Documents Department
open access

Status of LBL/LLNL FEL (free electron laser) research for two beam accelerator applications

Description: We review the status of free electron laser (FEL) research being conducted at LBL and LLNL as part of a broader program of research on two beam accelerators (TBAs). Induction accelerator-driven FELs for use as power sources for high-gradient accelerators are discussed, along with preliminary cost estimates for this type of power source. Finally, a promising new version of an FEL/TBA is described. 25 refs., 1 fig., 3 tabs.
Date: March 1, 1989
Creator: Hopkins, D. B. & Sessler, A. M.
Partner: UNT Libraries Government Documents Department
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