Author: Sannibale, F.
Paper Title Page
MOPPR075 Status of the APEX Beam Diagnostic and First Measurements 963
  • D. Filippetto, M.J. Chin, C.W. Cork, S. De Santis, L.R. Doolittle, W.E. Norum, C. F. Papadopoulos, G.J. Portmann, D.G. Quintas, F. Sannibale, R.P. Wells, M.S. Zolotorev
    LBNL, Berkeley, California, USA
  The APEX project aims to the construction of a high brightness high repetition rate photo-injector at LBNL. In its first phase a 750 keV electron bunch is produced at a maximum repetition rate of 1 MHz, with an adjustable charge per bunch spanning the pC-to-nC region. A load lock system is foreseen to test different cathodes without the need of breaking the vacuum and the downstream diagnostic is used to characterize the photo-emitted beam brightness. In the initial phase the main effort is directed toward the measurement of photocurrent, dark current, thermal emittance and electron beam kinetic energy. In a successive phase, diagnostic for full 6D phase space characterization of space charge dominated beams will be added to the beamline. We report and discuss the present diagnostic beamline layout, first beam measurements and future upgrades.  
TUPPP038 Electron Beam Collimation for the Next Generation Light Source 1695
  • C. Steier, P. Emma, H. Nishimura, C. F. Papadopoulos, F. Sannibale
    LBNL, Berkeley, California, USA
  Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
The Next Generation Light Source will deliver high (MHz) repetition rate electron beams to an array of free electron lasers. Because of the significant average current in such a facility, effective beam collimation is extremely important to minimize radiation damage to undulators, prevent quenches of superconducting cavities, limit dose rates outside of the accelerator tunnel and prevent equipment damage. This paper describes the conceptual design of the collimator system, as well as the results of simulations to test its effectiveness.
TUPPP074 Beam Dynamics Studies of a High-repetition Rate Linac Driver for a 4th-generation Light Source 1771
  • M. Venturini, J.N. Corlett, P. Emma, C. F. Papadopoulos, G. Penn, M. Placidi, J. Qiang, M.W. Reinsch, F. Sannibale, C. Steier, R.P. Wells
    LBNL, Berkeley, California, USA
  We present progress toward the design of a super-conducting linac driver of a high repetition rate FEL-based soft x-ray light source. The machine is intended to accept beams generated by the APEX* photocathode gun, operating in the MHz range, and deliver them to an array of SASE and seeded FEL beamlines. After reviewing the beam-dynamics considerations that are informing specific lattice choices we discuss the expected performance of the proposed machine design and its ability to meet the desired FEL specifications. We consider the merit of possible alternate designs (e.g., a one-stage compressor vs. a two-stage compressor) and the trade-offs between competing demands on the beam attributes (e.g., high peak current vs. acceptable energy spread).
* F. Sannibale et al., this conference.
WEEPPB004 Status of the APEX Project at LBNL 2173
  • F. Sannibale, B.J. Bailey, K.M. Baptiste, J.M. Byrd, C.W. Cork, J.N. Corlett, S. De Santis, L.R. Doolittle, J.A. Doyle, P. Emma, J. Feng, D. Filippetto, G. Huang, H. Huang, T.D. Kramasz, S. Kwiatkowski, W.E. Norum, H.A. Padmore, C. F. Papadopoulos, G.C. Pappas, G.J. Portmann, J. Qiang, D.G. Quintas, J.W. Staples, T. Vecchione, M. Venturini, M. Vinco, W. Wan, R.P. Wells, M.S. Zolotorev, F.A. Zucca
    LBNL, Berkeley, California, USA
  • M. J. Messerly, M.A. Prantil
    LLNL, Livermore, California, USA
  • C.M. Pogue
    NPS, Monterey, California, USA
  Funding: This work was supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231.
The Advanced Photo-injector Experiment (APEX) at the Lawrence Berkeley National Laboratory is focused on the development of a high-brightness high-repetition rate (MHz-class) electron injector for X-ray FEL applications. The injector is based on a new concept gun, utilizing a normal conducting 186 MHz RF cavity operating in cw mode in conjunction with high quantum efficiency photocathodes capable of delivering the required repetition rates with available laser technology. The APEX activities are staged in 3 main phases. In Phases 0 and I, the gun will be tested at its nominal energy of 750 keV and several different photocathodes are tested at full repetition rate. In Phase II, a pulsed linac will be added for accelerating the beam at several tens of MeV to reduce space charge effects and measure the high-brightness performance of the gun when integrated in an injector scheme. At Phase II energies, the radiation shielding configuration of APEX limits the repetition rate to a maximum of several Hz. Phase 0 is under commissioning, Phase I under installation, and initial activities for Phase II are underway. This paper presents an update on the status of these activities.
WEPPR031 Injector Beam Dynamics for a High-repetition Rate 4th-generation Light Source 3000
  • C. F. Papadopoulos, J.N. Corlett, P. Emma, D. Filippetto, G. Penn, J. Qiang, M.W. Reinsch, F. Sannibale, C. Steier, M. Venturini, R.P. Wells
    LBNL, Berkeley, California, USA
  Funding: This work was supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231.
We report on the beam dynamics studies and optimization methods for a high-repetition (1 MHz) photoinjector based on a VHF normal conducting electron source. The simultaneous goals of beam compression and preservation of 6-dimensional beam brightness have to be achieved in the injector, in order to accommodate a linac driven FEL light source. For this, a parallel, multiobjective optimization algorithm is used. We discuss the relative merits of different injector design points, as well as the constraints imposed on the beam dynamics by technical considerations such as the high repetition rate.
TUPPP070 Next Generation Light Source R&D and Design Studies at LBNL 1762
  • J.N. Corlett, B. Austin, K.M. Baptiste, D.L. Bowring, J.M. Byrd, S. De Santis, P. Denes, R.J. Donahue, L.R. Doolittle, P. Emma, D. Filippetto, G. Huang, T. Koettig, S. Kwiatkowski, D. Li, T.P. Lou, H. Nishimura, H.A. Padmore, C. F. Papadopoulos, G.C. Pappas, G. Penn, M. Placidi, S. Prestemon, D. Prosnitz, J. Qiang, A. Ratti, M.W. Reinsch, D. Robin, F. Sannibale, D. Schlueter, R.W. Schoenlein, J.W. Staples, C. Steier, C. Sun, T. Vecchione, M. Venturini, W. Wan, R.P. Wells, R.B. Wilcox, J.S. Wurtele
    LBNL, Berkeley, California, USA
  Funding: Work supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
LBNL is developing design concepts for a multi-beamline soft x-ray FEL array powered by a superconducting linear accelerator, operating with a high bunch repetition rate of approximately one MHz. The cw superconducting linear accelerator is supplied by an injector based on a high-brightness, high-repetition-rate photocathode electron gun. Electron bunches are distributed from the linac to the array of independently configurable FEL beamlines with nominal bunch rates up to 100 kHz in each FEL, and with even pulse spacing. Individual FELs may be configured for different modes of operation, and each may produce high peak and average brightness x-rays with a flexible pulse format, and with pulse durations ranging from sub-femtoseconds to hundreds of femtoseconds. In this paper we describe conceptual design studies and optimizations. We describe recent developments in the design and performance parameters, and progress in R&D activities.
THPPC088 LLRF Control Algorithm for APEX 3488
  • G. Huang, K.M. Baptiste, J.M. Byrd, L.R. Doolittle, F. Sannibale
    LBNL, Berkeley, California, USA
  Advanced photo-cathode experiment is an ongoing experiment of a high repetition rate low emittance VHF band gun experiment. A low level RF control and monitor subsystem is developed base on the 5 LLRF4 board. One of them is used for low level RF control and the other 4 are used as interlock and RF monitor at different point of the system. The laser is also controlled by the system to be synced to the RF system. This paper we summarize the control algorithm used in the system firmware.  
FRXBA01 Overview of Recent Progress on High Repetition Rate, High Brightness Electron Guns 4160
  • F. Sannibale
    LBNL, Berkeley, California, USA
  In the last few years, the formidable results of x-ray light sources based on FELs opened the door to classes of experiments not accessible before. Operating facilities have relatively low repetition rates (~ 10-100 Hz), and the natural step forward consists in the development of FEL light sources capable of extending their rates by orders of magnitude in the MHz regime. Additionally, ERL based x-ray facilities with their promise of outstanding performance also require extremely high, GHz-class repetition rates. The development of such facilities would represent the next revolutionary step in terms of science capability. To operate such light sources, an electron injector capable of MHz/GHz repetition rates and with the brightness required by X-ray FELs or ERLs is required. Such injector presently does not exist. In response to that, many groups around the world are intensively working on different schemes and technologies that show the potential for achieving the desired results. This presentation includes a description of the requirements for such injectors, an overview of the pursued technologies, and a review of the results obtained so far by the groups active in the field.  
slides icon Slides FRXBA01 [6.290 MB]