Electron injectors delivering relativistic electron beams with very high brightness are essential for a number of current and proposed electron accelerator applications. These high brightness beams are generally produced from photoemission cathodes. We formulate a limit on the electron beam brightness from such cathodes set by the transverse thermal energy of the electrons leaving the photocath...

Accelerator Test Facility at Brookhaven National Laboratory (BNL ATF) operates with 5 MeV photocathode gun and 70 MeV linac for different range of experiments with a few picoseconds and a few micrometers emittance electron bunch. Many conducted experiments require beam with good spatial resolution and short length as well. NdYaG laser pulse turns to the electron bunch in the gun with space char...

The University of Wisconsin-Madison has completed installation of a superconducting electron gun. Its concept was optimized to be the source for a CW free electron laser facility with multiple megahertz repetition rate end stations. This VHF superconducting configuration holds the promise of the highest performance for CW injectors. Initial commissioning efforts show that the cavity can achieve...

We present the design and fabrication of a micrometer-scale electron gun for the implementation of ultrafast low-energy electron diffraction from surfaces. A multi-step process involving photolithography and focused-ion-beam nanostructuring is used to assemble and electrically contact the photoelectron gun, which consists of a nanotip photocathode in a Schottky geometry and an einzel lens for b...

The parallel electron distribution function has been measured on an electron beam from a magnetron injection gun (MIG) using an E 11 B energy analyzer. The magnetic field, beam voltage and beam current were scaled down from normal operating parameters. The perpendicular velocity spread, inferred under the assumption that the electrons are mono-energetic, is relatively constant for electron velo...

In order to provide maximum physics benefits, the International Linear Collider (ILC) must have a highly polarized electron beam with a low emittance. High electron spin -polarization (>85%) is attainable with a modern GaAs photocathode illuminated by a circularly polarized laser. Low emittance is achievable with an rf photoinjector, and can be further improved with a round-to-flat beam transfo...

For the generation of picosecond (< 100 ps) electron beam pulses, we studied the RF modulation of a conventional triode electron gun. The feasibility study for this scheme has been experimentally investigated by modulating a triode gun of the Y-824 cathode-grid (KG) structure provided by the CPI Eimac, with 2.856-GHz pulsed RF’s generated by a solid-state amplifier (SSA). In this paper, we pres...