Related papers: Higher-order mode-based cavity misalignment measur…
Superconducting TESLA-type cavities are widely used to accelerate electrons in long bunch trains, such as in high repetition rate free electron lasers. The TESLA cavity is equipped with two higher order mode couplers and a fundamental power…
Existing FEL facilities often suffer from stability issues: so electron orbit, transverse electron optics, electron bunch compression and other parameters have to be readjusted often to account for drifts in performance of various…
Free-electron lasers (FELs) provide a revolutionary tool for capturing the structure and dynamics of matter in real time at the atomic scale. The size and cost of FELs can be substantially reduced by using laser wakefield acceleration…
We report experiments on field-free molecular alignment performed at FLASH, the free electron laser (FEL) in Hamburg. The impulsive alignment induced by a 100 fs near-infrared laser pulse in a rotationally cold CO_2 sample is characterized…
The Fermilab Accelerator Science and Technology (FAST) facility is currently in operation with its linac based on TESLA-type superconducting rf cavities. Using a 3-MHz micropulse repetition rate with a long macropulse composed of up to 3000…
The European XFEL is a new research facility currently under construction at DESY in the Hamburg area in Germany. From 2015 on, it will generate extremely intense X-ray flashes that will be used by researchers from all over the world. The…
The FLASH L-band (1.3 GHz) superconducting accelerator facility at DESY has a Low Level RF (LLRF) system that is similar to that envisioned for ILC. This system has extensive monitoring capability and was used to gather performance data…
With electron beam durations down to femtoseconds and sub-femtoseconds achievable in current state-of-the-art accelerators, longitudinal bunch length diagnostics with resolution at the attosecond level are required. In this paper, we…
The design of the proposed linear collider TESLA is based on 9-cell 1.3 GHz superconducting niobium cavities, operated in pulsed mode. Within the framework of an international collaboration the TESLA Test Facility (TTF) has been set up at…
An international team is currently investigating the best way to use Higher Order Modes (HOM) for beam diagnostics in 3.9 GHz cavities. HOMs are excited by charged particles when passing through an accelerating structure. Third harmonic…
High-brightness electron bunches, such as those generated and accelerated in free-electron lasers (FELs), can develop small-scale structure in the longitudinal phase space. This causes variations in the slice energy spread and current…
An electron beam entering an accelerator cavity excites higher order modes (HOM). These are radiated to HOM couplers and subsequently damped. They can also be used to facilitate beam position monitoring. The modes excited by off-axis beams…
For the development of the X-ray Free Electron Lasers test facility (SXFEL) at SINAP, ultra-short bunch is the crucial requirement for excellent lasing performance. It's a big challenge for deflecting cavity to measure the length of…
The conceptional design of the proposed linear electron-positron collider TESLA is based on 9-cell 1.3 GHz superconducting niobium cavities with an accelerating gradient of Eacc >= 25 MV/m at a quality factor Q0 > 5E+9. The design goal for…
Laser-driven grating type DLA (Dielectric Laser Accelerator) structures have been shown to produce accelerating gradients on the order of GeV/m. In simple $\beta$-matched grating structures due to the nature of the laser induced…
The driving engine of the Free Electron Laser in Hamburg (FLASH) is an L-band superconducting accelerator. It is designed to operate in burst mode with 800 microsecond pulse duration at a repetition rate of 10 Hz. The maximum accelerated…
The concept of Dielectric Laser Acceleration (DLA) provides highest gradients among non-plasma particle accelerators. However, stable beam transport and staging have not been shown experimentally yet. We present a scheme that confines the…
Free Electron Lasers (FEL) are commonly regarded as the potential key application of laser wakefield accelerators (LWFA). It has been found that electron bunches exiting from state-of-the-art LWFAs exhibit a normalized 6-dimensional beam…
The FLASH L-band (1.3 GHz) superconducting accelerator facility at DESY has a Low Level RF (LLRF) system that is similar to that envisioned for ILC. This system has extensive monitoring capability and was used to gather performance data…
The control of beam phase relative to the accelerating RF field within a superconducting cavity is important in many accelerator applications and is of particular importance for a free electron laser facility. As standard practice, the…