Simulations and measurements of the TTF phase-1 injector gun

International audienceThe TTF phase-1 injector will use a conventional thermionic triode gun as its electron source. The temporal structure of the injector will be obtained by the application of fast (<1 ns) pulses to the gun cathode. As it is necessary to operate the injector at a fixed average macropulse current of 8 mA, while having the ability to vary the repetition frequency of the micropulses, the gun has to function at peak currents varying from 100 mA to 400 mA. We report on both measurements and simulations (using EGUN) of the current-voltage characteristics of the TTF gun. In addition we report on measurements of the emittance of the gun over a limited range of current and voltage. The emittance is seen to be dependent upon the operating perveance and is smallest for perveances closest to the space-charge limited valu

First Observation of Self-Amplified Spontaneous Emission in a Free-Electron Laser at 109 nm Wavelength

We present the first observation of Self-Amplified Spontaneous Emission (SASE) in a free-electron laser (FEL) in the Vacuum Ultraviolet regime at 109 nm wavelength (11 eV). The observed free-electron laser gain (approx. 3000) and the radiation characteristics, such as dependency on bunch charge, angular distribution, spectral width and intensity fluctuations all corroborate the existing models for SASE FELs.Comment: 6 pages including 6 figures; e-mail: [email protected]

Developments in conditioning procedures for the TTF-III power couplers

JACoW web site http://accelconf.web.cern.ch/AccelConf/e06/Despite extensive experience in many laboratories on power conditioning of couplers for RF superconducting accelerators, it is still not a well understood procedure and can produce many unpredictable phenomena. There remains considerable interest in reducing the power coupler conditioning time necessary for superconducting linear accelerators. This paper presents studies of optimisation of the conditioning procedure for the couplers intended for use on the European XFEL project

Simulations and Measurements of the TTF phase-1 Injector Gun

The TTF phase-1 injector will use a conventional thermionic triode gun as its electron source. The temporal structure of the injector will be obtained by the application of fast (&lt; 1 ns) pulses to the gun cathode. As it is necessary to operate the injector at a fixed average macropulse current of 8 mA, while having the ability to vary the repetition frequency of the micropulses, the gun has to function at peak currents varying from 100 mA to 400 mA. We report on both measurements and simulations (using EGUN) of the currentvoltage characteristics of the TTF gun. In addition we report on measurements of the emittance of the gun over a limited range of current and voltage. The emittance is seen to be dependent upon the operating perveance and is smallest for perveances closest to the space-charge limited value. 1. INTRODUCTION The TTF phase-1 injector must provide the TTF linac with an average macropulse current of 8 mA. In addition it is forseen that this current should be provided usi..

Progress in the study and construction of the tesla test facility injector

International audienceA 500 MeV, 1.3 GHz superconducting linear accelerator is being studied and built to serve as a test facility for the TESLA linear collider project. The phase 1 injector, having an energy of 8-14 MeV and an intensity of 8 mA with a high duty cycle (800 microseconds, 10 Hz repetition rate), consists of a 250 keV electron gun, a 216.7 MHz subharmonic buncher and a superconducting capture cavity at the main linac frequency. The main characteristics (intensity, position, emittance, bunch length, energy spread) are to be measured using different techniques. A particular effort will be made on the use of optical transition radiation (OTR) for the determination of the transverse beam emittance as well as the bunch length. The injector, involving, the participation of three French laboratories (LAL, CEA/DAPNIA, IPN), will be tested partly in France (Orsay-Saclay) and then completely at DESY (Hamburg