Download or read book Investigations of Cumulative Beam Breakup in Radio frequency Linacs written by and published by . This book was released on 1991 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cumulative Beam Breakup in Radio frequency Linacs written by C.L. Bohn and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cumulative Beam Breakup in Radio frequency Linacs written by and published by . This book was released on 1990 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analytic model of cumulative beam breakup has been developed which is applicable to both low-velocity ion and high-energy electron linear accelerators. The model includes arbitrary velocity, acceleration, focusing, initial conditions, beam-cavity resonances, and variable cavity geometry and spacing along the accelerator. The model involves a continuum approximation'' in which the transverse kicks in momentum imparted by the cavities are smoothed over the length of the linac. The resulting equation of transverse motion is solved via the WKBJ method. Specific examples are discussed which correspond to limiting cases of the solution. 16 refs.

Download or read book Cumulative beam breakup in large scale linacs written by Kaoru Yokoya and published by . This book was released on 1986 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cumulative Beam Breakup in Linear Accelerators with Time dependent Parameters written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A formalism presented in a previous paper for the analysis of cumulative beam breakup (BBU) with arbitrary time dependence of the beam current and with misalignment of the cavities and focusing elements [J.R. Delayen, Phys. Rev. ST Accel. Beams 6, 084402 (2003)] is extended to include time dependence of the focusing and coupling between the beam and the dipole modes. Such time dependence, which could result from an energy chirp imposed on the beam or from rf focusing, is known to be effective in reducing BBU-induced instabilities and emittance growth. The analytical results are presented and applied to practical accelerator configurations and compared to numerical simulations.

Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 754 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cumulative Beam Breakup in Linear Accelerators with Arbitrary Beam Current Profile written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An analytic formalism for the solution of cumulative beam breakup in linacs with arbitrary beam current profile is developed. It is applied to obtain an expression for the transverse displacement of trains of bunches of finite length. The same formalism is used to investigate the beam breakup-enhanced displacement of beams caused by the misalignment of the deflecting structures or focusing elements.

Download or read book Cumulative Beam Breakup with Random Displacement of Cavities and Focusing Elements written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We have recently developed an analytical formalism for cumulative beam breakup in linear accelerators with arbitrary beam current profile. The same formalism could be used to investigate the beam breakup-enhanced displacement due to the misalignment of the cavities and the focusing elements. In this paper this analytical formalism is extended and applied to investigate the behavior of beams in misaligned pulsed and cw linear accelerators.

Download or read book Intense Microwave and Particle Beams written by and published by . This book was released on 1991 with total page 674 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.

Download or read book Effect of Rf Structure on Cumulative Beam Breakup written by and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We treat the effect of rf structure of a linac beam on cumulative beam breakup in the presence of external focusing. Starting with the difference equations of Helm and Loew, we derive two forms of an exact analytic solution for coasting beams: as a sum of products of Gegenbauer polynomials involving external focusing and rf structure, and as an integral involving these same parameters. The continuous-beam limit of Neil, Hall, and Cooper is obtained as the bunch separation goes to zero. An explicit solution is presented for the steady state, including modulation of the incoming displacement, showing both stable and unstable behavior with distance. Asymptotic amplitude expressions are derived for the transient solution, which can lead to even larger beam displacements. Approximate solutions also are obtained for accelerated and decelerated beams. Comparison with numerical simulations are presented.

Download or read book Application of Theory of Cumulative Beam Breakup in Linacs to Transverse Instabilities in Storage Rings written by Robert L. Gluckstern and published by . This book was released on 1984 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Intense Microwave and Particle Beams II written by Howard E. Brandt and published by . This book was released on 1991 with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sparking Limits Cavity Loading and Beam Breakup Instability Associated with High current Rf Linacs written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The limitations on high-current rf linacs due to gap sparking, cavity loading, and the beam breakup instability are studied. It appears possible to achieve cavity accelerating gradients as high as 35 MV/m without sparking. Furthermore, a linear analysis, as well as self-consistent particle simulations of a multipulsed 10 kA beam, indicated that only a negligible small fraction of energy is radiated into nonfundamental cavity modes. Finally, the beam breakup instability is analyzed and found to be able to magnify initial radial perturbations by a factor of no more than about 20 during the beam transit time through a 1 GeV accelerator.

Download or read book Beam Breakup in Superconducting Recirculating Linacs written by and published by . This book was released on 1988 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The performance and operational flexibility of superconducting recirculating linacs can be limited by a variety of collective phenomena which are grouped under the name beam breakup. In this note the various beam breakup phenomena found in recirculating superconducting radio frequency linacs are described and appraised relative to beam performance.

Download or read book Beam Breakup in Recirculating Linacs written by and published by . This book was released on 1991 with total page 2483 pages. Available in PDF, EPUB and Kindle. Book excerpt: In general, a recirculation path length in a recirculating accelerator has to be an integer multiple of RF wavelength if recirculations are all in the same direction. However, it is not necessary to require such a relation to be satisfied with respect to the bunching frequency, when the bunch repetition rate is different from the RF frequency. An analytic model of multipass beam breakup (BBU) in recirculating linacs studied by Bisognano and Gluckstern has been generalized to include the case of a subharmonic bunching scheme in the operation of such linacs.

Download or read book Cumulative Beam Breakup in Linear Accelerators with Random Displacement of Cavities and Focusing Elements written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A formalism presented in a previous paper for the analysis of cumulative beam breakup with arbitrary time dependence of the beam current [J.R. Delayen, Phys. Rev. ST Accel Beams 6, 084402 (2003)] is applied to the problem of beam breakup in the presence of random displacements of cavities and focusing elements. A closed-form solution is obtained and is applied to the behavior of a single bunch and to the steady-state and transient behavior of dc beams and beams composed of point-like bunches.