GeV Electron Beams from Cm-scale Channel Guided Laser Wakefieldaccelerator - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook GeV Electron Beams from Cm-scale Channel Guided Laser Wakefieldaccelerator write by . This book was released on 2007. GeV Electron Beams from Cm-scale Channel Guided Laser Wakefieldaccelerator available in PDF, EPUB and Kindle. Laser-wakefield accelerators (LWFA) can produce electricfields of order 10-100 GV/m suitable for acceleration of electrons torelativistic energies. The wakefields are excited by a relativisticallyintense laser pulse propagating through a plasma and have a phasevelocity determined by the group velocity of the light pulse. Twoimportant effects that can limit the acceleration distanceand hence thenet energy gain obtained by an electron are diffraction of the drivelaser pulse and particle-wake dephasing. Diffraction of a focusedultra-short laser pulse can be overcome by using preformed plasmachannels. The dephasing limit can be increased by operating at a lowerplasma density, since this results in an increase in the laser groupvelocity. Here we present detailed results on the generation of GeV-classelectron beams using an intense femtosecond laser beamand a 3.3 cm longpreformed discharge-based plasma channel [W.P. Leemans et al., NaturePhysics 2, 696-699 (2006)]. The use of a discharge-based waveguidepermitted operation at an order ofmagnitude lower density and 15 timeslonger distance than in previous experiments that relied on laserpreformed plasma channels. Laser pulses with peak power ranging from10-50 TW were guided over more than 20 Rayleigh ranges and high-qualityelectron beams with energy up to 1 GeV were obtained by channelling a 40TW peak power laser pulse. The dependence of the electron beamcharacteristics on capillary properties, plasma density, and laserparameters are discussed.
Laser Guiding for GeV Laser-Plasma Accelerators
Laser Guiding for GeV Laser-Plasma Accelerators - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Laser Guiding for GeV Laser-Plasma Accelerators write by . This book was released on 2005. Laser Guiding for GeV Laser-Plasma Accelerators available in PDF, EPUB and Kindle. Guiding of relativistically intense laser beams in preformed plasma channels is discussed for development of GeV-class laser accelerators. Experiments using a channel guided laser wakefield accelerator (LWFA) at LBNL have demonstrated that near mono-energetic 100 MeV-class electron beams can be produced with a 10 TW laser system. Analysis, aided by particle-in-cell simulations, as well as experiments with various plasma lengths and densities, indicate that tailoring the length of the accelerator, together with loading of the accelerating structure with beam, is the key to production of mono-energetic electron beams. Increasing the energy towards a GeV and beyond will require reducing the plasma density and design criteria are discussed for an optimized accelerator module. The current progress and future directions are summarized through comparison with conventional accelerators, highlighting the unique short term prospects for intense radiation sources based on laser-driven plasma accelerators.
GeV Electron Beams from a Cm-scale Accelerator
GeV Electron Beams from a Cm-scale Accelerator - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook GeV Electron Beams from a Cm-scale Accelerator write by . This book was released on 2006. GeV Electron Beams from a Cm-scale Accelerator available in PDF, EPUB and Kindle. GeV electron accelerators are essential to synchrotron radiation facilities and free electron lasers, and as modules for high-energy particle physics. Radio frequency based accelerators are limited to relatively low accelerating fields (10-50 MV/m) and hence require tens to hundreds of meters to reach the multi-GeV beam energies needed to drive radiation sources, and many kilometers to generate particle energies of interest to the frontiers of high-energy physics. Laser wakefield accelerators (LWFA) in which particles are accelerated by the field of a plasma wave driven by an intense laser pulse produce electric fields several orders of magnitude stronger (10-100 GV/m) and so offer the potential of very compact devices. However, until now it has not been possible to maintain the required laser intensity, and hence acceleration, over the several centimeters needed to reach GeV energies. For this reason laser-driven accelerators have to date been limited to the 100 MeV scale. Contrary to predictions that PW-class lasers would be needed to reach GeV energies, here we demonstrate production of a high-quality electron beam with 1 GeV energy by channeling a 40 TW peak power laser pulse in a 3.3 cm long gas-filled capillary discharge waveguide. We anticipate that laser-plasma accelerators based on capillary discharge waveguides will have a major impact on the development of future femtosecond radiation sources such as x-ray free electron lasers and become a standard building block for next generation high-energy accelerators.
Laser Wakefield Electron Acceleration
Laser Wakefield Electron Acceleration - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Laser Wakefield Electron Acceleration write by Karl Schmid. This book was released on 2011-05-18. Laser Wakefield Electron Acceleration available in PDF, EPUB and Kindle. This thesis covers the few-cycle laser-driven acceleration of electrons in a laser-generated plasma. This process, known as laser wakefield acceleration (LWFA), relies on strongly driven plasma waves for the generation of accelerating gradients in the vicinity of several 100 GV/m, a value four orders of magnitude larger than that attainable by conventional accelerators. This thesis demonstrates that laser pulses with an ultrashort duration of 8 fs and a peak power of 6 TW allow the production of electron energies up to 50 MeV via LWFA. The special properties of laser accelerated electron pulses, namely the ultrashort pulse duration, the high brilliance, and the high charge density, open up new possibilities in many applications of these electron beams.
Energy Spread Reduction of Electron Beams Produced Via Laser Wake
Energy Spread Reduction of Electron Beams Produced Via Laser Wake - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Energy Spread Reduction of Electron Beams Produced Via Laser Wake write by . This book was released on 2012. Energy Spread Reduction of Electron Beams Produced Via Laser Wake available in PDF, EPUB and Kindle. Laser wakefield acceleration of electrons holds great promise for producing ultra-compact stages of GeV scale, high quality electron beams for applications such as x-ray free electron lasers and high energy colliders. Ultra-high intensity laser pulses can be self-guided by relativistic plasma waves over tens of vacuum diffraction lengths, to give>1 GeV energy in cm-scale low density plasma using ionization-induced injection to inject charge into the wake at low densities. This thesis describes a series of experiments which investigates the physics of LWFA in the self-guided blowout regime. Beginning with high density gas jet experiments the scaling of the LWFA-produced electron beam energy with plasma electron density is found to be in excellent agreement with both phenomenological theory and with 3-D PIC simulations. It is also determined that self-trapping of background electrons into the wake exhibits a threshold as a function of the electron density, and at the densities required to produce electron beams with energies exceeding 1 GeV a different mechanism is required to trap charge into low density wakes. By introducing small concentrations of high-Z gas to the nominal He background the ionization-induced injection mechanism is enabled. Electron trapping is observed at densities as low as 1.3 x 1018 cm-3 in a gas cell target, and 1.45 GeV electrons are demonstrated for the first time from LWFA. This is currently the highest electron energy ever produced from LWFA. The ionization-induced trapping mechanism is also shown to generate quasi-continuous electron beam energies, which is undesirable for accelerator applications. By limiting the region over which ionization-induced trapping occurs, the energy spread of the electron beams can be controlled. The development of a novel two-stage gas cell target provides the capability to tailor the gas composition in the longitudinal direction, and confine the trapping process to occur only in a limited, defined region. Using this technique a 460 MeV electron beam was produced with an energy spread of 5%. This technique is directly scalable to multi-GeV electron beam generation with sub-percent energy spreads.
