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in subjects: "Particle Beams 430200* -- Particle Accelerators-- Beam Dynamics, Field Calculations, & Ion Optics"  
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Electron-beam envelopes and matching for a combined wiggler and alternating-gradient quadrupole channel

Description: This work studies the electron-beam envelopes and matching for a combined wiggler and alternating-gradient quadrupole field for a free-electron laser (FEL) that will be operated in the VUV or XUV wavelength region. The quadrupole field is assumed to vary continuously along the symmetry axis. The linearized equations of electron motion are solved analytically by using the two-scale perturbation method for a plane polarized wiggler. The electron-beam envelopes and the envelope equations, as well … more
Date: January 1, 1985
Creator: Wang, T. F. & Cooper, R. K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Crossing simple resonances

Description: A simple criterion governs the beam distortion and/or loss of protons on a fast resonance crossing. Results from numerical integrations are illustrated for simple sextupole, octupole, and 10-pole resonances.
Date: August 1, 1985
Creator: Collins, T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Importance of high order momentum terms in SLC optics

Description: The evaluation of background levels at the SLC relies, in several cases, on the proper representation of how low momentum electrons propagate through the Arcs and the Final Focus System (FFS). For example, beam - gas bremsstrahlung in the arcs causes electrons of up to 6% energy loss to be transported through to the IP; secondary showers on edges of masks and collimators yield debris with a very wide momentum spectrum. This note is a naive attempt at checking the validity of TRANSPORT and TURTL… more
Date: July 10, 1985
Creator: Kozanecki, W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Initial measurements of beam breakup instability in the advanced test accelerator

Description: This paper reports the measurements of beam breakup (BBU) instability performed on the Advanced Test Accelerator (ATA) up to the end of February, 1984. The main objective was to produce a high current usable electron beam at the ATA output. A well-known instability is BBU which arises from the accelerator cavity modes interacting with the electron beam. The dominant mode is TM/sub 130/ at a frequency of approximately 785 MHz. It couples most strongly to the beam motion and has been observed to … more
Date: May 13, 1985
Creator: Chong, Y.P.; Caporaso, G.J. & Struve, K.W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Effects of slots/holes in disks on frequencies of TM/sub 01/ and EH/sub 11/ waves in the disk-loaded waveguide

Description: The increase in the BBU threshold current is very important for the high and medium energy electron linacs because of a larger operating current attainable or a smaller emittance available at certain operating current. For this purpose, many means can be used, among which the improvement in the accelerating structure itself is always fundamental. SLAC's three-meter long section is unique with truly constant gradient performance. The theoretical analyses and operating experiences at SLAC have in… more
Date: March 1, 1985
Creator: Yao, C.G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Theories of statistical equilibrium in electron-positron colliding-beam storage rings

Description: In this lecture I introduce you to some recent theoretical work that represents a significant and long overdue departure from the mainstream of ideas on the physics of colliding- beam storage rings. The goal of the work in question is to understand analytically - without recourse to computer simulation - the role that dissipation and noise play in the observed colliding-beam behavior of electron-positron storage rings.
Date: January 1, 1985
Creator: Schonfeld, J.F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Landau damping in the SLAC linac

Description: In the SLC Landau damping can greatly stabilize the beam against changes in injection conditions into the linac. For example, by choosing phi/sub a/ = -15/sup 0/, n/sub a/ = 51, the jitter tolerances for 25% emittance growth can be relaxed by greater than a factor of 10, while sacrificing 1.6 GeV in final energy. Increasing the focusing, especially near the beginning of the linac, will lessen the energy penalty for a given amount of stability. For example, with the planned addition of more quad… more
Date: April 1, 1985
Creator: Bane, K. L. F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Relativistic klystron

Description: Theoretical analysis is presented of a relativisic klystron; i.e. a high-relativistic bunched electron beam which is sent through a succession of tuned cavities and has its energy replenished by periodic induction accelerator units. Parameters are given for a full-size device and for an experimental device using the FEL at the ETA; namely the ELF Facility. 6 refs., 2 figs.
Date: September 1, 1985
Creator: Marks, R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Collective accelerator for electron colliders

Description: A recent concept for collective acceleration and focusing of a high energy electron bunch is discussed, in the context of its possible applicability to large linear colliders in the TeV range. The scheme can be considered to be a member of the general class of two-beam accelerators, where a high current, low voltage beam produces the acceleration fields for a trailing high energy bunch.
Date: May 13, 1985
Creator: Briggs, R. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Multigigahertz beam-current and position monitor

Description: A self-integrating magnetic-loop device having a risetime of less than 175 ps has been developed to monitor the temporal behavior of the electron beam current and position within each 3.3-ns micropulse generated by the PHERMEX rf linear accelerator. Beam current is measured with a 2-GHz bandwidth by combining these loops in a four-port hybrid summer. Another application of these loops uses two 180/sup 0/ hybrids to give 2-GHz time-resolved beam position to an accuracy of 1 mm. These sensors are… more
Date: January 1, 1985
Creator: Carlson, R.L. & Stout, L.E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Transverse electron resonance accelerator

Description: Transverse (to the velocity, v, of the particles to be accelerated) electron oscillations are generated in high (e.g. solid) density plasmas by either an electromagnetic wave or by the field of charged particles traveling parallel to v. The generating field oscillates with frequency ..omega.. = ..omega../sub p/, where ..omega../sub p/ is the plasma frequency. The plasma is confined to a sequence of microstructures with typical dimensions of d approx. = 2..pi..c/..omega../sub p/, allowing the ge… more
Date: January 1, 1985
Creator: Csonka, P.L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Strong intrabeam scattering in heavy ion and proton beams

Description: Intrabeam scattering is the scattering of the particles in the beam from each other through the Coulomb forces that act between each pair of particles. This causes the beam dimensions to grow both longitudinally and transversely. In strong intrabeam scattering, the beam dimensions may grow by several fold, and the accelerator aperture is large enough to contain the beam as it grows. The growth rates may be very large initially, but they quickly decrease as the beam increases in size. The growth… more
Date: January 1, 1985
Creator: Parzen, G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Electron trajectories in a combined wiggler and alternating gradient quadrupole field

Description: This paper reports on studies of electron trajectories in a combined wiggler and alternating gradient quadrupole field. The quadrupole field is assumed to vary continuously along the symmetry axis. The linearized equations of electron motion are solved analytically for a plane-polarized wiggler by using the two-scale perturbation method. A comparison with the numerical solution is presented, and the conditions for unstable trajectories are discussed. 4 refs., 4 figs.
Date: January 1, 1985
Creator: Wang, T. F. & Cooper, R. K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Observations of accelerated high current low emittance beams in the SLC Linac

Description: The Linac of the SLAC Linear Collider (SLC) is required to accelerate several intense single electron and positron bunches to high energy while not enlarging their small transverse emittances. The improvements needed by the SLAC Linac to meet these goals have very stringent design criteria. As partial systems have become available, beam tests have been performed to confirm the designs. The results of those beam tests are discussed. Future plans of the improvement program are described. 13 refs.… more
Date: May 1, 1985
Creator: Seeman, J. T.; Ross, M. C.; Sheppard, J. C. & Stiening, R. F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Technology of magnetically driven accelerators

Description: The marriage of Induction Linac technology with Nonlinear Magnetic Modulators has produced some unique capabilities. It appears possible to produce electron beams with average currents measured in amperes, at gradients exceeding 1 MeV/meter, and with power efficiencies approaching 50%. A 2 MeV, 5 kA electron accelerator has been constructed at the Lawrence Livermore National Laboratory (LLNL) to demonstrate these concepts and to provide a test facility for high brightness sources. The pulse dri… more
Date: March 26, 1985
Creator: Birx, D. L.; Hawkins, S. A.; Poor, S. E.; Reginato, L. L.; Rogers, D., Jr. & Smith, M. W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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LAMPF transition-region mechanical fabrication

Description: The new Transition Region (TR-II) optimizes phase matching of H/sup +/ and H/sup -/ beams during simultaneous transport between the drift-tube linac and side-coupled linac at LAMPF. Improvements include, larger aperture, a straight beam track, greater beam path length adjustments, and better utility routing. Hardware density required innovative designs for magnets, mounting, vacuum, and utilities. Dipoles are powered by one constant current and one variable current supply which cause the fields… more
Date: January 1, 1985
Creator: Bush, E. D., Jr.; Gallegos, J. D. F.; Harrison, R.; Hart, V. E.; Hunter, W. T.; Rislove, S. E. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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