tags:
view citation format
12 papers
| title: | High Energy Gain of Trapped Electrons in a Tapered, Diffraction-Dominated Inverse-Free-Electron Laser |
| format: | preprint |
| year: | 2005 |
| 17 authors: | | | | | | | | | | | | | | | | | |
| abstract: | Energy gain of trapped electrons in excess of 20 MeV has been demonstrated in an Inverse-Free- Electron-Laser (IFEL) accelerator experiment. A 14.5 MeV electron beam is copropagated with a 400 GW CO2 laser beam in a 50 cm long undulator strongly tapered in period and ¯eld amplitude. The Rayleigh range of the laser, » 1.8 cm, is much shorter than the undulator length yielding a di®raction-dominated interaction. Experimental results on the dependence of the acceleration on injection energy, laser focus position, and laser power are discussed. Simulations, in good agreement with the experimental data, show that most of the energy gain occurs in the ¯rst half of the undulator at a gradient of 70 MeV/m and that the structure in the measured energy spectrum arises because of higher harmonic IFEL interaction in the second half of the undulator. |
| keywords: | |
| Download | View | Details | edit | delete | |
| title: | Commissioning of the Neptune photoinjector |
| format: | conference procceeding |
| conference: | 2001 Particle Accelerator Conference |
| year: | 2001 |
| 9 authors: | | | | | | | | | |
| abstract: | The status of the RF photoinjector in the Neptune advanced accelerator laboratory is discussed. The components of the photoinjector: the RF gun and booster linac, chicane compressor, and beam diagnostic systems are described. Measurement techniques used to diagnose the short pulse length, high brightness beam are detailed and measurements of emittance and pulse compression are given. The effect of the pulse compressor on transverse emittance is explored. (11 References). |
| keywords: | |
| Download | View | Details | edit | delete | |
| title: | Commissioning of the Neptune photoinjector |
| format: | conference procceeding |
| conference: | 1999 Particle Accelerator Conference |
| year: | 1999 |
| 21 authors: | | | | | | | | | | | | | | | | | | | | | |
| abstract: | The status of the commissioning of the RF photoinjector in the Neptune advanced accelerator laboratory is discussed. The component parts of the photoinjector, the RF gun, photocathode drive laser system, booster linac, RF system, chicane compressor, beam diagnostics systems, and control system are described. This injector is designed to produce short pulse length, high brightness electron beams. Experiments planned for the immediate future are described. Initial measurements of various beam parameters are presented. (10 References). |
| keywords: | |
| Download | View | Details | edit | delete | |
| title: | Very High Energy Gain at the Neptune Inverse Free Electron Laser Experiment |
| format: | journal article |
| year: | Dec 2004 |
| 16 authors: | | | | | | | | | | | | | | | | |
| abstract: | We report the observation of energy gain in excess of 20 MeV at the Inverse Free Electron Laser Accelerator experiment at the Neptune Laboratory at UCLA. A 14.5 MeV electron beam is injected in an undulator strongly tapered in period and field amplitude. The IFEL driver is a CO2 10.6 µm laser with power larger than 400 GW. The Rayleigh range of the laser, ~ 1.8 cm, is much shorter than the undulator length so that the interaction is diffraction dominated. A few per cent of the injected particles are trapped in a stable accelerating bucket. Electrons with energies up to 35 MeV are measured by a magnetic spectrometer. Three-dimensional simulations, in good agreement with the measured electron energy spectrum, indicate that most of the acceleration occurs in the first 25 cm of the undulator, corresponding to an energy gradient larger than 70 MeV/m. The measured energy spectrum also indicates that higher harmonic Inverse Free Electron Laser interaction takes place in the second section of the undulator. |
| keywords: | pbpl |
| Download | View | Details | edit | delete | |
| title: | A Novel Fabrication Technique for the Production of RF Photoinjectors |
| format: | conference procceeding |
| conference: | EPAC 2008 |
| year: | 2008 |
| 9 authors: | | | | | | | | | |
| abstract: | Recent developments in Solid Freeform Fabrication (SFF) technology may make it possible to design and produce near netshape copper structures for the next generation of very high duty factor, high gradient radio frequency (RF) photoinjectors. RF and thermal management optimized geometries could be fully realized without the usual constraints and compromises of conventional machining techniques. A photoinjector design incorporating SFF and results from an initial material feasibility study will be reported. |
| keywords: | pbpl_pub |
| Download | View | Details | edit | delete | |
| title: | Design and Fabrication of an X-Band traveling wave deflection mode cavity for longitudinal characterization of ultra-short electron beam pulses |
| format: | conference procceeding |
| conference: | EPAC 2008 |
| year: | 2008 |
| 9 authors: | | | | | | | | | |
| abstract: | An X-band Traveling wave Deflector mode cavity (XTD) has been developed at Radiabeam Technologies to perform longitudinal characterization of the subpicosecond ultra-relativistic electron beams. The device is optimized for the 100 MeV electron beam parameters at the Accelerator Test Facility (ATF) at Brookhaven National Laboratory, and is scalable to higher energies. An XTD is designed to operate at 11.424 GHz, and features short filling time, femtosecond resolution, and a small footprint. RF design, fabrication procedure, and commissioning plans are presented. An experimental program at ATF to utilize the deflector for compressed beam characterization is discussed, including proposed measurements of the phase space filamentation due to non-linear processes in a chicane compressor. |
| keywords: | pbpl_pub |
| Download | View | Details | edit | delete | |
| title: | Simulation of and progress towards a micron-scale laser-powered dielectric electron source |
| format: | conference procceeding |
| conference: | EPAC 2008 |
| year: | 2008 |
| 5 authors: | | | | | |
| abstract: | A dielectric, slab-symmetric structure for generating and accelerating low-energy electrons has been under study for the past two years. The resonant device is driven by a side-coupled laser and is configured to maintain field profiles necessary for synchronous acceleration and focusing of nonrelativistic particles. Intended applications of the structure include the production of radiation for medical treatments, imaging, and industrial uses. Results from 3D simulation of the structure geometry and its resonant properties are presented here. |
| keywords: | pbpl_pub |
| Download | View | Details | edit | delete | |
| title: | A real-time bunch length terahertz interferometer |
| format: | conference procceeding |
| conference: | EPAC 2008 |
| year: | 2008 |
| 5 authors: | | | | | |
| abstract: | The recent development of advanced photoinjectors and next generation light sources guides the progression towards high-current, ultra-short beams. The measurement of these short pulses, with sub-picosecond resolution, is essential for successful beam operation and optimization. This paper describes the development of a real-time, shotto-shot bunch length diagnostic utilizing a novel coherent terahertz radiation autocorrelation technique. The proposed diagnostic is called the real-time interferometer (RTI). |
| keywords: | pbpl_pub |
| Download | View | Details | edit | delete | |
| title: | High Average Current Betatrons for Industrial and Security Applications |
| format: | conference procceeding |
| conference: | PAC07 |
| year: | 2007 |
| 8 authors: | | | | | | | | |
| abstract: | The fixed-field alternating-gradient (FFAG) betatron has emerged as a viable alternative to RF linacs as a source of high-energy radiation for industrial and security applications. For industrial applications, high average currents at modest relativistic electron beam energies, typically in the 5 to 10 MeV range, are desired for medical product sterilization, food irradiation and materials processing. For security applications, high power x-rays in the 3 to 20 MeV range are needed for rapid screening of cargo containers and vehicles. In a FFAG betatron, high-power output is possible due to high duty factor and fast acceleration cycle: electrons are injected and accelerated in a quasi-CW mode while being confined and focused in the fixed-field alternating- gradient lattice. The beam is accelerated via magnetic induction from a betatron core made with modern low- loss magnetic materials. Here we present the design and status of a prototype FFAG betatron, called the Radiatron, as well as future prospects for these machines. |
| keywords: | pbpl_pub |
| Download | View | Details | edit | delete | |
| title: | Acceleration of electrons in a diffraction-dominated IFEL |
| format: | journal article |
| year: | 2004 |
| 16 authors: | | | | | | | | | | | | | | | | |
| abstract: | We report on the observation of energy gain in excess of 20 MeV at the Inverse Free Electron Laser Accelerator ex- periment at the Neptune Laboratory at UCLA. A 14.5 MeV electron beam is injected in a 50 cm long undulator strongly tapered both in period and field amplitude. A CO2 10.6 μm laser with power > 300 GW is used as the IFEL driver. The Rayleigh range of the laser ( ∼ 1.8 cm) is shorter than the undulator length so that the interaction is diffraction dom- inated. Few per cent of the injected particles are trapped in stable accelerating buckets and electrons with energies up to 35 MeV are detected on the magnetic spectrometer. Three dimensional simulations are in good agreement with the electron energy spectrums observed in the experiment and indicate that substantial energy exchange between laser and electron beam only occurs in the first 25-30 cm of the undulator. An energy gradient of > 70 MeV is inferred. In the second section of the undulator higher harmonic IFEL interaction is observed. |
| keywords: | pbpl |
| Download | View | Details | edit | delete | |
| title: | High Energy Gain of Trapped Electrons in a Tapered, Diffraction-Dominated Inverse-Free-Electron Laser |
| format: | journal article |
| year: | |
| 17 authors: | | | | | | | | | | | | | | | | | |
| abstract: | Energy gain of trapped electrons in excess of 20 MeV has been demonstrated in an inverse-freeelectron-laser (IFEL) accelerator experiment. A 14.5 MeVelectron beam is copropagated with a 400 GW CO2 laser beam in a 50 cm long undulator strongly tapered in period and field amplitude. The Rayleigh range of the laser, 1:8 cm, is much shorter than the undulator length yielding a diffraction-dominated interaction. Experimental results on the dependence of the acceleration on injection energy, laser focus position, and laser power are discussed. Simulations, in good agreement with the experimental data, show that most of the energy gain occurs in the first half of the undulator at a gradient of 70 MeV=m and that the structure in the measured energy spectrum arises because of higher harmonic IFEL interaction in the second half of the undulator. |
| keywords: | |
| Download | View | Details | edit | delete | |
| title: | High Energy gain IFEL at the UCLA Neptune Laboratory |
| format: | journal article |
| year: | |
| 16 authors: | | | | | | | | | | | | | | | | |
| abstract: | We report on the observation of energy gain in excess of 20MeV at the Inverse Free Electron Laser Accelerator experiment at the Neptune Laboratory at UCLA. A 14.5MeV electron beam is injected in a 50cm longundulator strongly tapered both in period and field amplitude. A CO210.6μm laser with power > 400GW is used as the IFEL driver. The Rayleigh range of the laser(∼1.8cm)is shorter than the undulator length so that the interaction is diffraction dominated. Few per cent of the injected particles are trapped instable accelerating buckets and electrons with energies up to 35 MeV are detected on the magnetic spectrometer. Three dimensional simulations are in good agreement with the electron energy spectrums observed in the experiment and indicate that substantial energy exchange between laser and electron beam only occurs in the first 25-30 cm of the undulator. Anenergygradientof>70MeVisinferred. In these cond section of the undulator higher harmonic IFEL interaction is observed. |
| keywords: | |
| Download | View | Details | edit | delete | |