Download or read book Research and Development Toward a 4 5 1 5 Angstrom Linac Coherent Light Source LCLS at SLAC written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years significant studies have been initiated on the feasibility of utilizing a portion of the 3km S-band accelerator at SLAC to drive a short wavelength (4.5-1.5 A) Linac Coherent Light Source (LCLS), a Free Electron Laser (FEL) operating in the Self- Amplified Spontaneous Emission (SASE) regime. Electron beam requirements for single-pass saturation in a minimal time include: (1) a peak current in the 7 kA range, (2) a relative energy spread of[lt]0.05%, and (3) a transverse emittance, [epsilon][r-m], approximating the diffraction limit condition[epsilon]=[lambda] / 4[pi], where lambda(m) is the output wavelength. Requirements on the insertion device include field error levels of 0.02% for keeping the electron bunch centered on and in phase with the amplified photons, and a focusing beta of 8 m/rad for inhibiting the dilution of its transverse density. Although much progress has been made in developing individual components and beam processing techniques necessary for LCLS operation down to approx. 20 A, a substantial amount of research and development is still required in a number of theoretical and experimental areas leading to the construction and operation of a 4.5-1.5 A LCLS. In this paper we report on a research and development program underway and in planning at SLAC for addressing critical questions in these areas.

Download or read book Research and Development Toward a 4 5 1 5 Linac Coherent Light Source LCLS at SLAC written by and published by . This book was released on 1995 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years significant studies have been initiated on the feasibility of utilizing a portion of the 3km S-band accelerator at SLAC to drive a short wavelength (4.5-1.5 A) Linac Coherent Light Source (LCLS), a Free Electron Laser (FEL) operating in the Self- Amplified Spontaneous Emission (SASE) regime. Electron beam requirements for single-pass saturation in a minimal time include: (1) a peak current in the 7 kA range, (2) a relative energy spread of>0.05%, and (3) a transverse emittance, [epsilon][r-m], approximating the diffraction limit condition [epsilon] = [lambda] / 4[pi], where lambda(m) is the output wavelength. Requirements on the insertion device include field error levels of 0.02% for keeping the electron bunch centered on and in phase with the amplified photons, and a focusing beta of 8 m/rad for inhibiting the dilution of its transverse density. Although much progress has been made in developing individual components and beam processing techniques necessary for LCLS operation down to approx. 20 A, a substantial amount of research and development is still required in a number of theoretical and experimental areas leading to the construction and operation of a 4.5-1.5 A LCLS. In this paper we report on a research and development program underway and in planning at SLAC for addressing critical questions in these areas.

Download or read book Issues and R D Critical to the LCLS written by and published by . This book was released on 2001 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Linac Coherent Light Source (LCLS) [LCLS Design Study Report, SLAC-R-521, (1998)] is a high brightness x-ray free-electron laser project based on the SLAC linac. A new photocathode rf gun serves as injector for the last kilometer of the linac, which is fitted with two-stages of bunch compression. Acceleration to 15-GeV produces intense 1.5-Å coherent radiation by self-amplified spontaneous emission in a long undulator. A multi-laboratory project collaboration is addressing the most challenging issues [H.-D. Nuhn, 22nd Intl. FEL Conf., Aug. 2000, Durham, NC], including: (1) feasibility of a stable injector with normalized emittance of 1 mm at 1 nC; (2) emittance control in the linac including effects of coherent synchrotron radiation in the bunch compressors; (3) stability of the final electron beam in the presence of charge, timing, and energy variations; (4) design, construction and alignment of a long planar undulator with 3-cm period and discrete periodic focusing lattice; (5) understanding and control of wakefields due to wall surface roughness in the undulator vacuum chamber; (6) radiation-matter interactions in the strong field regime with mirror and crystal optics for filtering and deflecting. These issues, and a project update, are presented.

Download or read book Linac Coherent Light Source LCLS Design Study Report written by and published by . This book was released on 1998 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Stanford Linear Accelerator Center (SLAC), in collaboration with Los Alamos National Laboratory, Lawrence Livermore National Laboratory, and the University of California at Los Angeles, is proposing to build a Free-Electron-Laser (FEL) R and D facility operating in the self-amplified spontaneous emission (SASE) mode in the wavelength range 1.5--15 Å. This FEL, called Linac Coherent Light Source (LCLS), utilizes the SLAC linac and produces sub-picosecond pulses of short wavelength x-rays with very high peak brightness and full transverse coherence. In this report, the Design Team has established performance parameters for all the major components of the LCLS and developed a layout of the entire system. Chapter 1 is the Executive Summary. Chapter 2 (Overview) provides a brief description of each of the major sections of the LCLS, from the rf photocathode gun, through the experimental stations and electron beam dump. Chapter 3 describes the scientific case for the LCLS. Chapter 4 provides a review of the principles of the FEL physics that the LCLS is based on, and Chapter 5 discusses the choice of the system's physical parameters. Chapters 6 through 10 describe in detail each major element of the system. Chapters 11 through 13 respectively cover undulator controls, mechanical alignment, and radiation issues.

Download or read book Radiation Safety Aspects of the Linac Coherent Light Source Project At SLAC written by A. Fasso and published by . This book was released on 2005 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Linac Coherent Light Source (LCLS) is a Self-Amplified Spontaneous Emission based Free Electron Laser (FEL) that is being designed and built at the Stanford Linear Accelerator Center (SLAC) by a multilaboratory collaboration. This facility will provide ultra-short pulses of coherent x-ray radiation with the fundamental harmonic energy tunable over the energy range of 0.82 to 8.2 keV. One-third of the existing SLAC LINAC will compress and accelerate the electron beam to energies ranging from 4.5 GeV to 14.35 GeV. The beam will then be transported through a 130-meter long undulator, emit FEL and spontaneous radiation. After passing through the undulator, the electron beam is bent to the main electron dump. The LCLS will have two experiment halls as well as x-ray optics and infrastructure necessary to make use of the FEL for research and development in a variety of scientific fields. The facility design will incorporate features that would make it possible to expand in future such that up to 6 independent undulators can be used. While some of the radiation protection issues for the LCLS are similar to those encountered at both high-energy electron linacs and synchrotron radiation facilities, LCLS poses new challenges as well. Some of these new issues include: the length of the facility and of the undulator, the experimental floor in line with the electron beam and the occupancy near zero degrees, and the very high instantaneous intensity of the FEL. The shielding design criteria, methodology, and results from Monte Carlo and analytical calculations are presented.

Download or read book Linac Coherent Light Source II LCLS II Conceptual Design Report written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The LCLS-II Project is designed to support the DOE Office of Science mission, as described in the 22 April 2010 Mission Need Statement. The scope of the Project was chosen to provide an increase in capabilities and capacity for the facility both at project completion in 2017 and in the subsequent decade. The Project is designed to address all points of the Mission Need Statement (MNS): (1) Expanded spectral reach; (2) Capability to provide x-ray beams with controllable polarization; (3) Capability to provide 'pump' pulses over a vastly extended range of photon energies to a sample, synchronized to LCLS-II x-ray probe pulses with controllable inter-pulse time delay; and (4) Increase of user access through parallel rather than serial x-ray beam use within the constraint of a $300M-$400M Total Project Cost (TPC) range. The LCLS-II Project will construct: (1) A hard x-ray undulator source (2-13 keV); (2) A soft x-ray undulator source (250-2,000 eV); (3) A dedicated, independent electron source for these new undulators, using sectors 10-20 of the SLAC linac; (4) Modifications to existing SLAC facilities for the injector and new shielded enclosures for the undulator sources, beam dumps and x-ray front ends; (5) A new experiment hall capable of accommodating four experiment stations; and (6) Relocation of the two soft x-ray instruments in the existing Near Experiment Hall (NEH) to the new experiment hall (Experiment Hall-II). A key objective of LCLS-II is to maintain near-term international leadership in the study of matter on the fundamental atomic length scale and the associated ultrafast time scales of atomic motion and electronic transformation. Clearly, such studies promise scientific breakthroughs in key areas of societal needs like energy, environment, health and technology, and they are uniquely enabled by forefront X-ray Free Electron Laser (X-FEL) facilities. While the implementation of LCLS-II extends to about 2017, it is important to realize that LCLS-II only constitutes a stepping stone to what we believe is needed over a longer time scale. At present, a practical time horizon for planning is about 15 years into the future, matching that of worldwide planning activities for competitive X-FEL facilities in Europe and Asia. We therefore envision LCLS-II as an important stage in development to what is required by about 2025, tentatively called LCLS-2025, for continued US leadership even as new facilities around the world are being completed. We envision LCLS primarily as a hard x-ray FEL facility with some soft x-ray capabilities. A survey of planned X-FEL facilities around the world suggests that US planning to 2025 needs to include an internationally competitive soft x-ray FEL facility which complements the LCLS plans outlined in this document.

Download or read book Prospects for High Power Linac Coherent Light Source LCLS Development in the 1000 1 Wavelength Range written by and published by . This book was released on 1994 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electron bunch requirements for single-pass saturation of a Free-Electron Laser (FEL) operating at full transverse coherence in the Self-Amplified Spontaneous Emission (SASE) mode include: (1) a high peak current, (2) a sufficiently low relative energy spread, and (3) a transverse emittance {var_epsilon}[r-m] satisfying the condition {var_epsilon} ≤ [lambda]A/4[pi], where [lambda][m] is the output wavelength of the FEL. In the insertion device that induces the coherent amplification, the prepared electron bunch must be kept on a trajectory sufficiently collinear with the amplified photons without significant dilution of its transverse density. In this paper we discuss a Linac Coherent Light Source (LCLS) based on a high energy accelerator such as, e.g., the 3km S-band structure at the Stanford Linear Accelerator Center (SLAC), followed by a long high-precision undulator with superimposed quadrupole (FODO) focusing, to fulfill the given requirements for SASE operation in the 1000Å--1Å range. The electron source for the linac, an RF gun with a laser-excited photocathode featuring a normalized emittance in the 1--3 mm-mrad range, a longitudinal bunch duration of the order of 3 ps, and approximately 10−9 C/bunch, is a primary determinant of the required low transverse and longitudinal emittances. Acceleration of the injected bunch to energies in the 5--25 GeV range is used to reduce the relative longitudinal energy spread in the bunch, as well as to reduce the transverse emittance to values consistent with the cited wavelength regime. Two longitudinal compression stages are employed to increase the peak bunch current to the 2--5 kA levels required for sufficiently rapid saturation. The output radiation is delivered, via a grazing-incidence mirror bank, to optical instrumentation and a multi-user beam line system. Technological requirements for LCLS operation at 40Å, 4.5Å, and 1.5Å are examined.

Download or read book Linac Coherent Light Source LCLS Conceptual Design Report written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Stanford Linear Accelerator Center, in collaboration with Argonne National Laboratory, Brookhaven National Laboratory, Los Alamos National Laboratory, Lawrence Livermore National Laboratory, and the University of California at Los Angeles, have collaborated to create a conceptual design for a Free-Electron-Laser (FEL) R & D facility operating in the wavelength range 1.5-15 Å. This FEL, called the ''Linac Coherent Light Source'' (LCLS), utilizes the SLAC linac and produces sub-picosecond pulses of short wavelength x-rays with very high peak brightness and full transverse coherence. The first two-thirds of the SLAC linac are used for injection into the PEP-II storage rings. The last one-third will be converted to a source of electrons for the LCLS. The electrons will be transported to the SLAC Final Focus Test Beam (FFTB) Facility, which will be extended to house a 122-m undulator system. In passing through the undulators, the electrons will be bunched by the force of their own synchrotron radiation to produce an intense, spatially coherent beam of x-rays, tunable in energy from 0.8 keV to 8 keV. The LCLS will include two experiment halls as well as x-ray optics and infrastructure necessary to make use of this x-ray beam for research in a variety of disciplines such as atomic physics, materials science, plasma physics and biosciences. This Conceptual Design Report, the authors believe, confirms the feasibility of constructing an x-ray FEL based on the SLAC linac.

Download or read book FEL Research and Development at the SLAC Sub Picosecond Photon Source SPPS written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: An upgrade project to the SLAC linac allows ultra-short electron bunches to be interleaved with the routine high-energy physics program operation, for use with an undulator to produce short-pulse, high-brightness x-rays. The linac upgrade comprises of the installation in the summer of 2002 of a bunch compressor chicane of similar design to the Linac Coherent Light Source (LCLS) project. A final compression stage in the high-energy Final Focus Test Beam (FFTB) line compresses the 28 GeV, 3.4 nC electron bunch to 80 femtoseconds fwhm, where a 5 m section of undulator (K=4.45) will produce 1.5 Å x-rays with 3*107 photons per pulse and a peak brightness of 4*1024 photons mm−2 mrad−2 s−1 (0.1% BW). The facility will allow us to test the dynamics and associated technology of bunch compression and gain valuable experience for the LCLS using the SLAC linac. New ultra-short electron bunch diagnostic techniques will be developed hand in hand with the same ultra-fast laser technology to be used for LCLS. Issues of high peak power (27 GW) x-ray transport and optics can be addressed at this facility as well as pump-probe and ultra-fast laser timing and stability issues.

Download or read book Linac Coherent Light Source LCLS at 2 4 Nm Using the SLAC Linac written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors describe the possible use of the SLAC linac to drive a unique, powerful, short wavelength Linac Coherent Light Source (LCLS). Using the FEL principle, lasing is achieved in a single pass of a high peak current electron beam through a long undulator by self-amplified-spontaneous-emission (SASE). The main components are a high-brightness electron RF gun with a photocathode, two electron bunch length compressors, the existing SLAC linac, beam diagnostics, and a long undulator combined with a FODO quadrupole focusing system. The RF gun, to be installed about 1 km from the end of the SLAC linac, would produce a single bunch of 6 x 10[sup 9] electrons with an invariant emittance of about 3 mm-mrad and a bunch length of about 500 [mu]m. That bunch is then accelerated to 100 MeV and compressed to a length of about 200 [mu]m. The main SLAC linac accelerates the bunch to 2 GeV were a second bunch compressor reduces the length to 30--40 [mu]m and produces a peak current of 2--3 kA. The bunch is then accelerated to 7--8 GeV and transported to a 50--70 m long undulator. Using electrons below 8 GeV, the undulator could operate at wavelengths down to 2 nm, producing about 10 GW peak power in sub-ps light pulses. At a linac repetition rate of 120 Hz, the average power is about 1 W. Linac operation at lower beam energies provides longer wavelength radiation. After the undulator, the beam is deposited in a dump. The LCLS light pulses are then distributed to multiple user stations using grazing incident mirrors. Length compression, emittance control, phase stability, FEL design criteria, and parameter tolerances are discussed. A demonstration experiment is also described which uses the SLAC linac and (possibly) the PALADIN undulator to study SASE to power saturation at wavelengths of 40--360 nm.

Download or read book The LCLS X Ray FEL at SLAC written by and published by . This book was released on 1999 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The design status and R and D plan of a 1.5 Angstrom SASE-FEL at SLAC, called the Linac Coherent Light Source (LCLS), are described. The LCLS utilizes one third of the SLAC linac for the acceleration of electrons to about 15 GeV. The FEL radiation is produced in a long undulator and is directed to an experimental area for its utilization. The LCLS is designed to produce 300 fsec long radiation pulses at the wavelength of 1.5 Angstrom with 9 GW peak power. This radiation has much higher brightness and coherence, as well as shorter pulses, than present 3rd generation sources. It is shown that such leap in performance is now within reach, and is made possible by the advances in the physics and technology of photo-injectors, linear accelerators, insertion devices and free-electron lasers.

Download or read book Linac Design for the LCLS Project at SLAC written by and published by . This book was released on 1997 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Linac Coherent Light Source (LCLS) at SLAC is being designed to produce intense, coherent 0.15-nm x-rays. These x-rays will be produced by a single pass of a 15 GeV bunched electron beam through a long undulator. Nominally, the bunches have a charge of 1 nC, normalized transverse emittances of less than 1.5[pi] mm-mr and an rms bunch length of 20 [mu]m. The electron beam will be produced using the last third of the SLAC 3-km linac in a manner compatible with simultaneous operation of the remainder of the linac for PEP-II. The linac design necessary to produce an electron beam with the required brightness for LCLS is discussed, and the specific linac modifications are described.

Download or read book The Linac Coherent Light Source Project at SLAC written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Linac Coherent Light Source (LCLS) is an x-ray free-electron laser project presently under construction at SLAC. A 14-GeV high-brightness electron beam is produced in the last kilometer of the existing SLAC linear accelerator, generating coherent x-ray radiation in a 130-m long undulator. The peak x-ray brightness is 10 orders of magnitude higher than existing 3rd generation light sources with a wavelength of 1.5 Angstroms and a pulse duration as short as one femtosecond, opening limitless scientific opportunities in the world of the ultra-small and ultra-fast. This presentation will describe the project scope and status, highlighting especially the key accelerator physics challenges.

Download or read book The LINAC Coherent Light Source and Radiological Issues During the Commissioning written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Linac Coherent Light Source (LCLS) at SLAC National Accelerator Laboratory is the world's first X-ray free electron laser (XFEL). Pulses of x-ray laser light from LCLS will be many orders of magnitude brighter and several orders of magnitude shorter than what can be produced by other x-ray sources available in the world. These characteristics will enable frontier new science in many areas. This paper describes the LCLS beam parameters and lay-out. The general radiological issues during commissioning are presented, such as radiation dose rates and integrated doses outside the enclosure. Also, specific radiological issues related to X-ray free electron lasers are discussed. XFEL with high peak power will burn through high-Z materials. The X-ray beam needs to be blocked by stoppers when the downstream areas are occupied. LCLS stoppers feature a piece of boron carbide (B4C), 10 mm thick. B4C is one of the best materials since it has a low absorption coefficient for X-rays and a high melting temperature. Theoretical calculations indicate that the unfocused fluence of the LCLS XFEL beam should be about one order of magnitude below the damage threshold for bulk B4C, for 830 eV FEL radiation. However, these calculations have not been tested experimentally and cannot be validated until LCLS begins providing 830 eV XFEL pulses. This paper describes the test plan for using the initial LCLS radiation to evaluate the survivability of B4C and reports the preliminary results. Another major issue for LCLS is the potential radiation damage to the LCLS undulator magnets during operation. TLD dosimeters were installed along the LCLS undulators for each period of two or three weeks. This paper reports the integrated doses along the undulators with and without XFEL generation.

Download or read book Proceedings of the 1997 Particle Accelerator Conference written by and published by . This book was released on 1998 with total page 1322 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Overview of Near Field Vs Far Field Radiation Characteristics of the Linac Coherent Light Source LCLS written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The unusually long insertion devices being prepared for Angstrom-wavelength Free Electron Lasers (FELs) will generate spectral-angular distributions in the proposed experimental areas that are substantially different from those conventionally calculated for the far field. In this paper we provide a general overview of near-field effects and report on initial computational simulations of near vs. far field distributions for the SLAC linac Coherent Light Source (LCLS) undulator, an insertion device approximately 140 meters long. The properties of the coherent radiation as a limiting case of the near-field emission, for the special condition of a microbunched beam radiating along the undulator axis, are reviewed.

Download or read book Gl ssa gl sses st n Europ written by Hellas Hypurgeion Ethnikēs Paideias kai Thrēskeumatōn and published by . This book was released on 2001 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: