In the TESLA Test Facility (TTF), short bunches with low emittance are needed for the operation of a free electron laser. Several stages of bunch compression by means of magnetic chicanes will be used to reach the required peak current. The second stage of the bunch compression system, bunch compressor II, has been taken into operation recently. We describe design and instrumentation of the bun...

We report on the status of emittance tuning techniques at the CESR Test Accelerator (CesrTA). The CesrTA experimental program requires that we operate in a variety of machine lattices, each with the smallest possible emittance. We utilize high-bandwidth BPM electronics for fast, precision measurements of orbit, betatron phase, transverse coupling, and dispersion. Analysis of the data and implem...

BESSY VSR, a scheme where 1.7 ps and 15 ps long bunches (rms) can be stored simultaneously in the BESSY II storage ring has recently been proposed [1]. The strong longitudinal bunch focusing is achieved by superconducting high gradient RF cavities. If the bunch fill pattern exhibits a significant inhomogeneity, e.g. due to gaps, transient beam loading causes a distortion of the longitudinal pha...

In a plasma wakefield accelerator in the nonlinear regime the accelerated bunch electrons oscillate in a pure ion column. They emit strong synchrotron, also known as betatron radiation, in the keV to MeV photon range [1]. In previous experiments with a single electron bunch the oscillating electrons where distributed symmetrically about the beam axis or the ion column axis. However, with a driv...

A positron be additional focusing is g cloud densities. This pa Linear Collider Collaboration Tech Notes Single Bunch Electron Cloud Effects in the NLC Beam Delivery System David Chen, Arthur Chang, M. T. F. Pivi, T. O. Raubenheimer Stanford Linear Accelerator Center Stanford University Stanford, CA am passing through a linear collider beam delivery line is finely focused to desired specificati...

Characteristics of electron-cooled bunched ion beams have been studied using the particle-tracking simulation in which the space-charge force and the force induced through the transverse broadband impedance are taken into account. The beams become space-charge dominated during the bunching of coasting beams. The simulation results show that the beams meet the transverse instability which can be...

The TTF Free Electron Laser needs very short bunches to produce self-amplified spontaneous emission (SASE). This short bunch length is produced in a magnetic bunch compressor where the trajectories of particles with different energy have different path length in a way that the bunch is longitudinally compressed. As a parasitic effect the wake fields produced by the passing bunch will have the p...

A dual-axis, synchroscan streak camera was used to measure longitudinal bunch profiles in three storage rings at SLAC: the PEP-II lowand high-energy rings, and SPEAR3. At high currents, both PEP rings exhibit a transient synchronous-phase shift along the bunch train due to RF-cavity beam loading. Bunch length and profile asymmetry were measured along the train for a range of beam currents. To a...

For several years, a large variety of beams have been prepared in the LHC injectors, such as single-bunch and multi-bunch beams, with 25 ns, 50 ns and 75 ns bunch spacings, nominal and intermediate intensities per bunch. As compared to the nominal LHC beam (i.e. with nominal bunch intensity and 25 ns spacing) the other beams can be produced with lower transverse emittances. Beams of low transve...

In order to achieve high luminosity in CLIC, ultra-low emittance bunches have to be generated in both electron and positron damping rings. To achieve this goal, big energy loss per turn in the wigglers has to be compensated by the RF system. This results in very strong beam loading transients affecting the longitudinal bunch position and bunch length. In this paper, the conceptual design of the...