Related papers: Dark Current Studies for SwissFEL

For the SwissFEL project, an advanced high gradient low emittance gun is under development. Reliable operation with an electric field, preferably above 125 MV/m at a 4 mm gap, in the presence of an UV laser beam, has to be achieved in a…

Field emission or dark current from RF electron guns is problematic for accelerators for several reasons, and can be more difficult to predict, measure and understand, compared to the main beam. The work presented here is a study of the…

Dark current and multiple electron impacts (multipacting), as for example observed in radio frequency (RF) structures of accelerators, are usually harmful to the equipment and the beam quality. These effects need to be suppressed to…

Undesirable electron field emission (a.k.a. dark current) in high gradient RF photocathode guns deteriorates the quality of photoemission current and limits the operational gradient. To improve the understanding of dark current emission, a…

The SwissFEL Injector Test Facility operated at the Paul Scherrer Institute between 2010 and 2014, serving as a pilot plant and testbed for the development and realization of SwissFEL, the X-ray Free-Electron Laser facility under…

High-gradient acceleration is a key research area that could enable compact linear accelerators for future colliders, light sources, and other applications. In the pursuit of high-gradient operation, RF breakdown limits the attainable…

The S-band linear accelerator, which was built to be the source of particles and the front end of the Advanced Photon Source injector, is now also being used to support a low-energy undulator test line (LEUTL) and to drive a free-electron…

In the framework of the Low Emittance Gun (LEG) project, high gradient acceleration of a low emittance electron beam will be necessary. In order to achieve this acceleration a -500 kV, 250 ns FWHM, pulse will be applied in between two…

There is a growing demand for X-ray Free-electron lasers (FELs) in various science fields, in particular for those with short pulses, larger photon fluxes and shorter wavelengths. The level of X-ray power and the pulse energy depend on the…

The SwissFEL light-facility will provide coherent X-rays in the wavelength region 7-0.7 nm and 0.7-0.1 nm. In SwissFEL, view-screens and wire-scanners will be used to monitor the transverse profile of a 200/10pC electron beam with a…

Recent studies of the performance of radio-frequency (RF) copper cavities operated at cryogenic temperatures have shown a dramatic increase in the maximum achievable surface electric field. We propose to exploit this development to enable a…

The room temperature continuous wave (CW) very-high-frequency (VHF) gun is one of the candidates for the electron gun of the high-repetition-rate free-electron lasers (FELs). The VHF gun operates with a cathode gradient of ~ 20 MV/m and an…

Advanced accelerator-based light sources such as free electron lasers (FEL) accelerate highly relativistic electron beams to generate incredibly short (10s of femtoseconds) coherent flashes of light for dynamic imaging, whose brightness…

High-bunch-charge photoemission electron-sources operating in a continuous wave (CW) mode are required for many advanced applications of particle accelerators, such as electron coolers for hadron beams, electron-ion colliders, and…

High-gain free-electron lasers (FELs) are becoming important light sources at short wavelengths such as the EUV and X-ray regimes. A particularly promising concept is the regenerative amplifier FEL (RAFEL), which can greatly increase the…

An ultracold electron source based on near-threshold photoionization of a laser-cooled and trapped atomic gas is presented in this work. Initial DC acceleration to $\sim$10 keV and subsequent acceleration of the created bunches to 100 keV…

At SwissFEL, a fully non-invasive characterization of the beam energy distribution can be performed by means of a Synchrotron-Radiation-Monitor (SRM) imaging in the visible the transverse profile of the electron beam in a magnetic chicane.…

A Free Electron Laser (FEL) facility utilizing a recirculated Superconducting Radio Frequency (SRF) linear accelerator (linac) provides the opportunity to achieve about five times greater photon energy than an unrecirculated linac of…

Radiofrequency (RF) electron guns operating at high accelerating gradients offer a pathway to producing bright electron bunches. Such beams are expected to revolutionize many areas of science: they could form the backbone of next-generation…

Millicharged particles are generic in theories of dark sectors. A cosmic or local abundance of them may be produced by the early universe, stellar environments, or the decay or annihilation of dark matter/dark energy. Furthermore, if such…