Nothing epitomizes the mystery of life more than the spatial organization and dynamics of the cytoplasm. How can a bunch of molecules, no matter how sophisticated, generate spatially complex behavior on a scale that is much larger than the molecules themselves? In my view, we will be done as cell biologists when we can predict the structure and dynamics of cells from DNA sequence. That goal is ...

We have directly measured the mm-wave wake fields induced by subpicosecond, intense relativistic electron bunches in a diamond loaded accelerating structure via the dielectric wake-field acceleration mechanism. Fields produced by a leading drive beam were used to accelerate a trailing witness electron bunch which followed the driving bunch at an adjustable distance. The energy change of the wit...

A novel, non-invasive method of measuring the beam energy at the International Linear Collider is proposed. Laser light collides head-on with beam particles and either the energy of the Compton scattered electrons near the kinematic endpoint is measured or the positions of the Compton backscattered γ-rays, the edge electrons and the unscattered beam particles are recorded. A compact layout for ...

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...

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...

A novel, non-invasive method of measuring the beam energy at the International Linear Collider is proposed. Laser light collides head-on with beam particles and either the energy of the Compton scattered electrons near the kinematic end-point is measured or the positions of the Compton backscattered γ-rays, the edge electrons and the unscattered beam particles are recorded. A compact layout for...

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...

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...

Particle accelerators at X-band frequencies have been shown to reach gradients of greater than 100 MV/m [1,2]. Such technology permits more compact accelerators. One of our aims at the Colorado State University (CSU) Accelerator Laboratory is to adapt this technology to our L-band (1.3 GHz) accelerator system to increase our overall beam energy; however, we would like to do this in a passive ma...