Related papers: Field Emission Dark Current of Technical Metallic …
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…
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…
The properties of the electron source define the ultimate limit of the beam quality in linear accelerators like Free Electron Lasers (FEL). The goal is to develop an electron gun delivering beam emittance lower than current state of the…
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…
For the Low Emittance Gun (LEG) project at Paul Scherrer Institute a stable and reliable high voltage pulsed generator was needed in order to study low emittance beams generation and transport. The system had to provide variable asymmetric…
Field Emitting Arrays (FEAs) are a promising alternative to the conventional cathodes in different vacuum electronic devices such as traveling wave tubes, electron accelerators and etc. Electrical gating and modulation capabilities,…
A device has been built and tested, in which a ceramic superconducting cathode and a copper anode cause electrical discharges in low pressure gases, at temperatures between 50 and 70 K. The electrodes are connected to a capacitors array…
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…
A pulsed electron gun that can produce MHz repetition rate nanosecond pulses is described. The gun uses a Pierce grid in combination with an anode to extract electrons from a tungsten filament cathode. The electrons emerging from the anode…
High-energy-density flows through dense matter are needed for effective progress in the production of laser-driven intense sources of energetic particles and radiation, in driving matter to extreme temperatures creating state regimes…
The specific form of one electrode capacitive discharge was studied in long tubes filled with high purity neon or argon at pressure 1-4 Torr. The main feature of the discharge is the low rate (less than 10 kHz) of the voltage pulses of…
The emission from an electron in the field of a relativistically strong laser pulse is analyzed. At pulse intensities of J > 2 10^22 W/cm2 the emission from counter-propagating electrons is modified by the effects of Quantum ElectroDynamics…
Ultrafast transmission electron microscopy (UTEM) has emerged as a versatile technique for the time-resolved imaging of nanoscale dynamics on timescales down to few-hundred attoseconds but the temporal and spatial resolutions are still…
Femtosecond electron bunches with keV energies and eV energy spread are needed by condensed matter physicists to resolve state transitions in carbon nanotubes, molecular structures, organic salts, and charge density wave materials. These…
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…
Experimental measurements using the OMEGA EP laser facility demonstrated direct laser acceleration (DLA) of electron beams to (505 $\pm$ 75) MeV with (140 $\pm$ 30)~nC of charge from a low-density plasma target using a 400 J, picosecond…
Theory of electron emission by metallic photocathodes under the exposure of long wavelength lasers will be studied. Energy of photons in long wavelength lasers is less than the work function of the photocathode material, and can only emit…
A novel kind of electron beam sustained discharge is presented in which a 12keV electron beam is combined with a 2.45GHz microwave power to excite argon gas at atmospheric pressure in a continuous mode of operation. Optical emission…
The process of nonlinear electron emission from a metal surface under the action of femtosecond laser pulse with moderate intensity $\sim10^{11}$~W/cm$^2$ is considered. One-dimensional model is formulated, taking into account the advantage…