Download or read book Multipass Beam Breakup in the CEBAF Superconducting Linac May 1986 written by Joseph J. Bisognano and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multipass Beam Breakup in the Continuous Electron Beam Accelerator Faility Superconducting Linac written by Joseph J. Bisognano and published by . This book was released on 1986 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multipass Beam Breakup in the CEBAF Superconducting Linac written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Beam breakup (BBU) instabilities in superconducting linacs are a significant issue due to the potentially high Q values of the cavity higher order modes (HOMs). The CEBAF accelerator, which employs high CW current and 5- pass recirculation through two superconducting linacs, poses unique instability problems. An experimental investigation of multipass BBU along with energy recovery has been completed using a single recirculation through the CEBAF injector linac. Experimental results are compared with computer simulation of multipass BBU.

Download or read book Multipass Beam Breakup in Recirculating Linacs July 1986 written by Joseph J. Bisognano and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Studies of Multipass Beam Breakup and Energy Recovery Using the CEBAF Injector Linac written by and published by . This book was released on 1993 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Beam breakup (BBU) instabilities in superconducting linacs are a significant issue due to the potentially high Q values of the cavity higher order modes (HOMs). The CEBAF accelerator, which employs high CW current and 5-pass recirculation through two superconducting linacs, poses unique instability problems. An experimental investigation of multipass BBU along with energy recovery has been completed using a single recirculation through the CEBAF injector linac. Experimental results are compared with computer simulation of multipass BBU.

Download or read book Multipass Beam Breakup in Recirculating Linacs written by and published by . This book was released on 1987 with total page 2060 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multipass beam breakup, a transverse beam instability generated by coherent excitation of cavity higher order modes in a recirculating linac, is a particular concern in designs utilizing superconducting technology. In this paper, an analytic model is presented that includes a description of this effect for a distribution of cavities along the linac with several recirculations in an impulse approximation. For N passes and M cvities, solution of the resulting equations reduces in general to finding M zeros of a 2(N-1) dimensional determinant or equivalently the M eigenvalues of an M-dimensional matrix. The parametric dependence of this system on higher order mode frequencies and Q, lattice functions, and transit times is discussed. Numerical examples are presented to clarify these issues and to model the CEBAF superconducting linac, where threshold currents are found to exceed design currents by more than an order of magnitude.

Download or read book Multipass Beam Breakup Study at Jefferson Lab for the 12 GeV CEBAF Upgrade written by Ilkyoung Shin and published by . This book was released on 2013 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Studies of Multipass Beam Breakup and Energy Recovery Using the CEBAF Injector Linac May 1993 written by Nicholas Sereno and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Calculating Beam Breakup in Superconducting Linear Accelerators written by and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: As the intensity of a particle beam passing through a linear accelerator is raised, interactions between particles play an increasingly prominent role in determining the overall dynamics of the beam. These many body effects, known collectively as beam breakup, tend to degrade the quality of the transported beam, and hence they must be calculated to accurately predict the evolution of the beam as it traverses the accelerator. Several codes which compute various collective effects have been developed and used to simulate the dynamics of beams passing through superconducting accelerator structures. All the codes use the same basic algorithm: the beam is tracked through elements giving the focusing forces on the particles, and at the appropriate locations in the linac, localized forces are impressed on the particles which model the electromagnetic interactions. Here, a difficulty is that the usual ''Coulomb'' interaction between particles is changed by the electromagnetic environment of the accelerator. By such calculations it has been shown that recirculating linear accelerators such as the one being built at the Continuous Electron Beam Accelerator Facility (CEBAF) should remain stable against multipass beam breakup instability as long as the average current does not exceed about 20 mA, that the beam quality at CEBAF will be degraded when the single bunch charge approaches 109 electrons, and that the beam quality of superconducting linacs that are optimized for high current transport begins to decrease at around 101° electrons per bunch. The latter result is of interest to individuals who would use superconducting linacs as beam sources for free electron lasers or for superconducting colliders for high energy physics research.

Download or read book Energy Research Abstracts written by and published by . This book was released on 1988 with total page 1472 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multipass Beam Breakup in Recirculating Linacs written by Joseph J. Bisognano and published by . This book was released on 1987 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book 1986 Linear Accelator Conference Proceedings written by and published by . This book was released on 1986 with total page 662 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Beam Breakup Simulations of the Saclay Recirculation Linac October 1986 written by Geoffrey Krafft and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Cure for Multipass Beam Breakup in Recirculating Linacs written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We investigate a method to control the multipass dipole beam breakup instability in a recirculating linac including energy recovery. Effectiveness of an external feedback system for such a goal is shown clearly in a simplified model. We also verify the theoretical result with a simulation study.

Download or read book A METHOD TO CONTROL MULTIPASS BEAM BREAKUP IN RECIRCULATING LINACS written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We investigate a method to control the multipass dipole beam breakup instability in a recirculating linac including energy recovery. Effectiveness of an external feedback system for such a goal is shown clearly in a simplified model. We also verify the theoretical result with a simulation study.

Download or read book Optics of Beam Recirculation in the CEBAF CW Linac May 1986 written by David Douglas and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Studies of Energy Recovery Linacs at Jefferson Laboratory written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An energy recovering linac (ERL) offers an attractive alternative for generating intense beams of charged particles by approaching the operational efficiency of a storage ring while maintaining the superior beam quality typical of a linear accelerator. Two primary physics challenges exist in pushing the frontier of ERL performance. The first is energy recovering a high energy beam while demonstrating operational control of two coupled beams in a common transport channel. The second is controlling the high average current effects in ERLs, specifically a type of beam instability called multipass beam breakup (BBU). This work addresses both of these issues. A successful 1 GeV energy recovery demonstration with a maximum-to-injection energy ratio of 51:1 was carried out on the Continuous Electron Beam Accelerator Facility at Jefferson Laboratory in an effort to address issues related to beam quality preservation in a large scale system. With a 1.3 km recirculation length and containing 312 superconducting radio frequency (SRF) cavities, this experiment has demonstrated energy recovery on the largest scale, and through the largest SRF environment, to date. The BBU instability imposes a potentially severe limitation to the average current that can be accelerated in an ERL. Simulation results for Jefferson Laboratory's 10 kW free electron laser (FEL) Upgrade Driver predict the occurrence of BBU below the nominal operating current. Measurements of the threshold current are described and shown to agree to within 10% of predictions from BBU simulation codes. This represents the first time the codes have been benchmarked with experimental data. With BBU limiting the beam current, several suppression schemes were developed. These include direct damping of the higher-order mode using two different cavity-based feedbacks and modifying the electron beam optics to reduce the coupling between the beam and mode. Specifically the effect of implementing (1) point-to-point focusing (2) a reflection of the betatron planes about 45± and (3) a rotation of the betatron planes by 90± is measured. Each method increased the threshold current for stability. Beam optical control methods proved to be so effective that they are routinely used in the operation of the 10 kW FEL Upgrade.