F. Sannibale

University of California, Berkeley, Berkeley, California, United States

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Publications (167)165.38 Total impact

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    ABSTRACT: This paper describes the scientific aims and potentials as well as the preliminary technical design of IRIDE, an innovative tool for multi-disciplinary investigations in a wide field of scientific, technological and industrial applications. IRIDE will be a high intensity “particles factory”, based on a combination of high duty cycle radio-frequency superconducting electron linacs and of high energy lasers. Conceived to provid eunique research possibilities for particle physics, for condensed matter physics,chemistry and material science, for structural biology and industrial applications, IRIDE will open completely new research possibilities and advance our knowledge in many branches of science and technology. IRIDE is also supposed to be realized in subsequent stages of development depending on the assigned priorities.
    Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 03/2014; 740:138-146. DOI:10.1016/j.nima.2013.11.040 · 1.32 Impact Factor
  • Fernando Sannibale
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    ABSTRACT: High brightness electron sources have been one of the driving forces behind the spectacular results achieved in the last decade by accelerator-based applications. Indeed, X-Ray FELs, with their 10-fold orders of magnitude increase in peak brightness, probably represent the best example of it. New ambitious proposals for X-ray FELs and ERLs, as well as inverse Compton sources for X- or gamma-ray production, are now requiring operation at MHz-GHz repetition rates. In response to that, a number of groups around the world have been actively working in developing high-brightness high-duty cycle electron injectors capable of driving such machines. The high repetition rate requirement cannot be met by the existing low-repetition rate high-brightness injector schemes, and new technologies are under investigation. This paper includes a description of the requirements for such injectors, an overview of the pursued technologies and schemes, a description of the main beam dynamics issues associated with the different choices, and a number of examples of the results obtained so far by the groups active in the field.
    Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 02/2014; 740. DOI:10.1016/j.nima.2013.10.021 · 1.32 Impact Factor
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    ABSTRACT: In this paper we report on start-to-end simulation of a next generation light source based on a high repetition rate free electron laser (FEL) driven by a CW superconducting linac. The simulation integrated the entire system in a seamless start-to-end model, including birth of photoelectrons, transport of electron beam through 600 m of the accelerator beam delivery system, and generation of coherent x-ray radiation in a two-stage self-seeding undulator beam line. The entire simulation used the real number of electrons (̃2 billion electrons/bunch) to capture the details of the physical shot noise without resorting to artificial filtering to suppress numerical noise. The simulation results shed light on several issues including the importance of space-charge effects near the laser heater and the reliability of x-ray radiation power predictions when using a smaller number of simulation particles. The results show that the microbunching instability in the linac can be controlled with 15 keV uncorrelated energy spread induced by a laser heater and demonstrate that high brightness and flux 1 nm x-ray radiation (̃1012 photons/pulse) with fully spatial and temporal coherence is achievable.
    Physical Review Special Topics - Accelerators and Beams 02/2014; 17(3). DOI:10.1103/PhysRevSTAB.17.030701 · 1.52 Impact Factor
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    ABSTRACT: The Advanced Light Source (ALS) at Berkeley Lab has been updated many times and remains as one of the brightest sources for soft x-rays worldwide. However, recent developments in technology, accelerator physics and simulation techniques open the door to much larger future brightness improvements. Similar to proposals at several other 3rd generation sources, this could be achieved by reducing the horizontal emittance with a new ring based on a multi-bend achromat lattice, reusing the existing tunnel, as well as much of the infrastructure and beamlines. After studying candidate lattice designs, development efforts in the last year have concentrated on technology and physics challenges in four main areas: Injection, Vacuum Systems, Magnets and Insertion Devices, as well as main and harmonic RF systems.
    5th International Particle Accelerator Conference (IPAC 2014), Dresden, Germany; 01/2014
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    ABSTRACT: Since the last EPAC2000 Conference, both the peak and integrated luminosity of the e+e- collider DAΦNE, Italian Φ–factory, have grown by an order of magnitude. In this paper we describe the steps that have led to the luminosity increase and discuss our plans for further luminosity upgrade.
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    ABSTRACT: This report describes the scientific aims and potentials as well as the preliminary technical design of IRIDE, an innovative tool for multi-disciplinary investigations in a wide field of scientific, technological and industrial applications. IRIDE will be a high intensity 'particle factory', based on a combination of a high duty cycle radio-frequency superconducting electron linac and of high energy lasers. Conceived to provide unique research possibilities for particle physics, for condensed matter physics, chemistry and material science, for structural biology and industrial applications, IRIDE will open completely new research possibilities and advance our knowledge in many branches of science and technology. IRIDE will contribute to open new avenues of discoveries and to address most important riddles: What does matter consist of? What is the structure of proteins that have a fundamental role in life processes? What can we learn from protein structure to improve the treatment of diseases and to design more efficient drugs? But also how does an electronic chip behave under the effect of radiations? How can the heat flow in a large heat exchanger be optimized? The scientific potential of IRIDE is far reaching and justifies the construction of such a large facility in Italy in synergy with the national research institutes and companies and in the framework of the European and international research. It will impact also on R&D work for ILC, FEL, and will be complementarity to other large scale accelerator projects. IRIDE is also intended to be realized in subsequent stages of development depending on the assigned priorities.
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    ABSTRACT: The planned Next Generation Light Source at LBNL is designed to deliver MHz repetition rate electron beams to an array of free electron lasers. Because of the high beam power approaching one MW in such a facility, effective beam collimation is extremely important to minimize ra- diation damage, prevent quenches of superconducting cav- ities, limit dose rates outside of the accelerator tunnel and prevent equipment damage. We describe the conceptual de- sign of a collimation system, including detailed simulations to verify its effectiveness.
    FEL 2013, New York, NY; 01/2013
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    ABSTRACT: The Next Generation Light Source at LBNL will deliver MHz repetition rate electron beams to an array of free elec- tron lasers. Because of the high beam power approaching one MW in such a facility, effective beam collimation is ex- tremely important to minimize radiation damage, prevent quenches of superconducting cavities, limit dose rates out- side of the accelerator tunnel and prevent equipment dam- age. This paper describes the conceptual design of a colli- mation system, including detailed simulations to verify its effectiveness.
    IPAC2013, Shanghai, China; 01/2013
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    ABSTRACT: The Advanced Photoinjector Experiment (APEX) at the Lawrence Berkeley National Laboratory is dedicated to the development of a high-brightness high-repetition rate (MHz-class) electron injector for x-ray free-electron laser (FEL) and other applications where high repetition rates and high brightness are simultaneously required. The injector is based on a new concept rf gun utilizing a normal-conducting (NC) cavity resonating in the VHF band at 186 MHz, and operating in continuous wave (cw) mode in conjunction with high quantum efficiency photocathodes capable of delivering the required charge at MHz repetition rates with available laser technology. The APEX activities are staged in three phases. In phase 0, the NC cw gun is built and tested to demonstrate the major milestones to validate the gun design and performance. Also, starting in phase 0 and continuing in phase I, different photocathodes are tested at the gun energy and at full repetition rate for validating candidate materials to operate in a high-repetition rate FEL. In phase II, a room-temperature pulsed linac is added for accelerating the beam at several tens of MeV to reduce space charge effects and allow the measurement of the brightness of the beam from the gun when integrated in an injector scheme. The installation of the phase 0 beam line and the commissioning of the VHF gun are completed, phase I components are under fabrication, and initial design and specification of components and layout for phase II are under way. This paper presents the phase 0 commissioning results with emphasis on the experimental milestones that have successfully demonstrated the APEX gun capability of operating at the required performance.
    Review of Modern Physics 10/2012; 15(10):103501. DOI:10.1103/PhysRevSTAB.15.103501 · 42.86 Impact Factor
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    ABSTRACT: 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, pre- vent quenches of superconducting cavities, limit dose rates outside of the accelerator tunnel and prevent equipment damage. This paper describes the early conceptual design of a collimation system, as well as initial results of simula- tions to test its effectiveness.
    IPAC 2012, New Orleans, Louisiana, USA; 01/2012
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    ABSTRACT: We report on on-going studies of a superconducting CW linac driver intended to support a high repetition rate FEL operating in the soft x-rays spectrum. We present a pointdesign for a 1.8 GeV machine tuned for 300 pC bunches and delivering low-emittance, low-energy spread beams as needed for the SASE and seeded beamlines.
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    ABSTRACT: The development of undulator technologies capable of generating sub-cm undulator periods is assuming an increasing importance in X-ray free electron laser (FEL) applications. Indeed, such devices jointly with the high brightness electron beams already demonstrated at operating facilities would allow for lower energy, more compact electron linacs with a beneficial impact on the size and cost of X-ray FEL facilities.A novel design super-conducting undulator is being developed at the Lawrence Berkeley National Laboratory (LBNL) with the potential of sub-cm periods with reasonably large undulator parameter and gap. The potential and capability of such undulator technology need to be experimentally demonstrated.In this paper, the possibility of constructing an infrared FEL by combining the new undulator with the high brightness beam from the APEX injector facility at LBNL is investigated.Calculations show that the resulting FEL, when operated in self-amplified-spontaneous-emission mode, is expected to deliver a saturated power of almost a MW within a ∼4m undulator length, in a single-spike of coherent radiation at ∼2μm wavelength.It will be also shown that the small-period of the undulator associated with the relatively low energy of the APEX beam, forces the FEL to operate in a regime with unusual and interesting characteristics. The alternative option of laser seeding the FEL is also briefly examined, showing the potential to reduce the saturation length even further.
    Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 12/2011; 660(1):138-146. DOI:10.1016/j.nima.2011.09.042 · 1.32 Impact Factor
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    ABSTRACT: Requirements and challenges for high-brightness electron injectors operating in a high-repetition-rate X-ray FEL are described. Schemes presently under development or study are reviewed, and their advantages and limitations are compared. Beam dynamics and engineering/technological aspects are addressed, with a particular emphasis placed on how the high-repetition-rate requirement impacts the choice of cathodes and of gun/accelerator technologies, and on how those choices consequently impact beam dynamics.
    Journal of Modern Optics 09/2011; 58(16):1419-1437. DOI:10.1080/09500340.2011.601328 · 1.17 Impact Factor
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    ABSTRACT: An upgrade project is under way to further improve the brightness of the Advanced Light Source at Berkeley Lab by reducing its horizontal emittance from 6.3 to 2.2 nm (effective emittance in the straights from 6.4 to 2.5 nm). This will result in a brightness increase by a factor of three for bend magnet beamlines and at least a factor of two for insertion device beamlines and will keep the ALS competitive with newer sources. This paper presents an overview of the upgrade project with emphasis on the nonlinear beam dynamics simulations. It also discusses in a more general way the techniques used at LBNL for finding optimum lattices (e.g. the ones with maximum brightness) and optimizing the particle dynamics, thereby increasing beam lifetime and stability.
    Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 09/2011; 649(1):25-29. DOI:10.1016/j.nima.2010.11.077 · 1.32 Impact Factor
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    ABSTRACT: With the scientific successes of the soft X-ray FLASH facility in Germany and the recent spectacular commissioning of the Linac Coherent Light Source at SLAC, free electron lasers are poised to take center stage as the premier source of tunable, intense, coherent photons of either ultra-short time resolution or ultra-fine spectral resolution, from the far infrared to the hard X-ray regime. This paper examines the state of the art in FEL performance and the underlying enabling technologies. It evaluates the state of readiness of the three basic machine architectures—SASE FELs, seeded FELs, and FEL oscillators—for the major X-ray science user facilities on the 5–10 years time scale and examines the challenges that lie ahead for FELs to achieve their full potential throughout the entire spectral range. In soft and hard X-rays, high longitudinal coherence, in addition to full transverse coherence, will be the key performance upgrade; ideas using laser-based or self-seeding or oscillators can be expected to be qualitatively superior to today's SASE sources. Short pulses, from femtoseconds to attoseconds, can be realistically envisioned. With high repetition rate electron sources coupled to superconducting radiofrequency linear accelerators, unprecedented average beam brightness will be possible and many users would be served simultaneously by a single accelerator complex.
    Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 06/2010; 618(1-3-618):69-96. DOI:10.1016/j.nima.2010.02.274 · 1.32 Impact Factor
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    ABSTRACT: The fabrication and installation at the Lawrence Berkeley National Laboratory of a high-brightness high-repetition rate photo-gun, based on a normal conducting 187 MHz (VHF) RF cavity operating in CW mode, is in an advanced phase. The cavity will generate an electric field at the cathode plane of ~ 20 MV/m to accelerate the electron bunches up to ~ 750 keV, with peak current, energy spread and transverse emittance suitable for FEL and ERL applications. The gun vacuum system has been designed for achieving pressures compatible with the use of "delicate" high quantum efficiency semiconductor cathodes to generate up to a nC bunches at MHz repetition rate with present laser technology. Several photo-cathode/laser systems are under consideration, and in particular photo-cathodes based on K 2 CsSb are being developed for the gun and have already achieved a QE of 8% at 532 nm wavelength, or close to 20% including the Schottky barrier lowering. The cathode will be operated by a μJ fiber laser in conjunction with refractive transverse beam shaping to create a flat top transverse profile, as well as a birefringent pulse stacker to create a flat top temporal profile. The present status and the plan for future activities are presented.
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    ABSTRACT: The Next Generation Light Source (NGLS) is a design concept, under development at LBNL, for a 10beamline xray FEL array powered by a superconducting linear accelerator of ~2 GeV, operating with a 1 MHz bunch repetition rate. The CW superconducting linear accelerator is supplied by a high-brightness, high-repetition-rate photocathode electron gun. Beam is distributed from the linac to the array of independently configurable FEL beamlines with nominal bunch rates up to 100 kHz, with even pulse spacing. Individual FELs may be configured for EEHG, HGHG, SASE, or oscillator mode of operation, and will produce high peak and average brightness x-rays with a flexible pulse format ranging from sub-femtoseconds to hundreds of femtoseconds.
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    ABSTRACT: Storage ring lattice design is a highly constrained multiobjective optimization problem. The objectives can include lattice functions or derived quantities like emittance, brightness, or luminosity while simultaneously fulfilling constraints such as linear stability of the lattice. In this paper we explore the use of multiobjective genetic algorithms (MOGA) to find globally optimized lattice settings in a storage ring. Using the Advanced Light Source (ALS) for illustration, three examples of MOGA are shown and analyzed—(i) using three fit parameters to optimize the straight section betatron function and the natural emittance, (ii) using three fit parameters to optimize the photon brightness of bending magnet and insertion device source points in the lattice and (iii) a six parameter fit creating alternating high and low horizontal betatron functions in subsequent straight sections while still minimizing the natural emittance. Making use of one of the main benefits of MOGA, we also study the trade-offs in the optimization objectives between sets of optimal solutions.
    Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 10/2009; 609(1):50-57. DOI:10.1016/j.nima.2009.08.027 · 1.32 Impact Factor
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    ABSTRACT: Several recent reports have identified the scientific requirements for a future soft X-ray light source [1, 2, 3, 4, 5], and a high-repetition-rate free-electron laser (FEL) facility responsive to them is being studied at Lawrence Berkeley National Laboratory (LBNL) [6]. The facility is based on a continuous-wave (CW) superconducting linear accelerator with beam supplied by a high-brightness, high-repetition-rate photocathode electron gun operating in CW mode, and on an array of FELs to which the accelerated beam is distributed, each operating at high repetition rate and with even pulse spacing. Dependent on the experimental requirements, the individualFELs may be configured for either self-amplified spontaneous emission (SASE), seeded highgain harmonic generation (HGHG), echo-enabled harmonic generation (EEHG), or oscillator mode of operation, and will produce high peak and average brightness x-rays with a flexible pulse format ranging from sub-femtoseconds to hundreds of femtoseconds. This new light source would serve a broad community of scientists in many areas of research, similar to existing utilization of storage ring based light sources. To reduce technical risks and constructioncosts, accelerator research, development, and design studies at LBNL target the most critical components and systems of the facility. We are developing a high-repetition-rate low-emittance electron gun, high quantum efficiency photocathodes, and have embarked on design and optimization of the electron beam accelerator, FEL switchyard, and array of FELs. We continue our work on precision timing and synchronization systems critical for time-resolved experiments using pump-probe techniques.
    Synchrotron Radiation News 08/2009; 22(5). DOI:10.1080/08940880903256817
  • J. Weber, M. Chin, F. Sannibale, W. Barry
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    ABSTRACT: A new bunch cleaning system has been designed and is currently in operation in the storage ring of the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory. The new system provides for high bunch purity, arbitrary filling patterns, and is compatible with the various ALS user operation modes. Design details and performance results of the new system will be described.
    Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 03/2009; 600(2-600):376-382. DOI:10.1016/j.nima.2008.11.144 · 1.32 Impact Factor

Publication Stats

835 Citations
165.38 Total Impact Points

Institutions

  • 2008–2014
    • University of California, Berkeley
      Berkeley, California, United States
  • 2002–2012
    • Lawrence Berkeley National Laboratory
      • Advanced Light Source Facility
      Berkeley, California, United States
  • 1995–2000
    • INFN - Istituto Nazionale di Fisica Nucleare
      Frascati, Latium, Italy