M. Bergamaschi
A5034825409- Particle Accelerators and Free-Electron Lasers
- Laser-Plasma Interactions and Diagnostics
- Particle accelerators and beam dynamics
- Particle Detector Development and Performance
- Magnetic confinement fusion research
- Gyrotron and Vacuum Electronics Research
- Radiation Detection and Scintillator Technologies
- Advanced X-ray Imaging Techniques
- Optical Systems and Laser Technology
- Particle physics theoretical and experimental studies
- Atomic and Molecular Physics
- Crystallography and Radiation Phenomena
- Terahertz technology and applications
- Laser-Matter Interactions and Applications
- Astrophysics and Cosmic Phenomena
- Advanced Optical Sensing Technologies
- Radiation Therapy and Dosimetry
- Laser Design and Applications
- Plasma Diagnostics and Applications
- Laser-induced spectroscopy and plasma
- Medical Imaging Techniques and Applications
- Electromagnetic Simulation and Numerical Methods
- Ion-surface interactions and analysis
- Pulsed Power Technology Applications
- Electron and X-Ray Spectroscopy Techniques
Max Planck Institute for Physics
2021-2024
Campbell Collaboration
2020-2023
European Organization for Nuclear Research
2018-2021
Royal Holloway University of London
2017-2020
We show in experiments that a long, underdense, relativistic proton bunch propagating plasma undergoes the oblique instability, which we observe as filamentation. determine threshold value for ratio between transverse size and skin depth instability to occur. At threshold, outcome of experiment alternates filamentation self-modulation (evidenced by longitudinal modulation into microbunches). Time-resolved images density distribution reveal grows an observable level late along bunch,...
Plasma wakefield acceleration is a promising technology to reduce the size of particle accelerators. The use high energy protons drive wakefields in plasma has been demonstrated during Run 1 AWAKE programme at CERN. Protons 400 GeV drove that accelerated electrons 2 under 10 m plasma. collaboration now embarking on with main aims demonstrate stable accelerating gradients 0.5–1 GV/m, preserve emittance electron bunches and develop sources scalable 100s metres beyond. By end 2, scheme should...
Experimental results show that hosing of a long particle bunch in plasma can be induced by wakefields driven short, misaligned preceding bunch. Hosing develops the plane misalignment, self-modulation perpendicular plane, at frequencies close to electron frequency, and are reproducible. Development depends on misalignment direction, its growth extent proton charge. Results have main characteristics theoretical model, relevant other plasma-based accelerators represent first characterization...
A long, narrow, relativistic charged particle bunch propagating in plasma is subject to the self-modulation (SM) instability. We show that SM of a proton can be seeded by wakefields driven preceding electron bunch. timing reproducibility and control are at level small fraction modulation period. With this seeding method, we independently amplitude seed with charge growth rate Seeding leads larger than instability case.
We report on the observation of incoherent Cherenkov radiation emitted by a 5.3 GeV positron beam circulating in Cornell electron-positron storage ring as passes close vicinity surface fused silica radiator (i.e., at distance larger than 0.8 mm). The shape was designed order to send photons towards detector, consisting compact optical system equipped with an intensified camera. allows both measurements 2D images and angular distribution including polarization study. corresponding light...
We present the observation and detailed investigation of coherent Cherenkov diffraction radiation (CChDR) in terms spectral-angular characteristics. Electromagnetic simulations have been performed to optimize design a prismatic dielectric radiator performance detection system with aim providing longitudinal beam diagnostics. Successful experimental validations organized on CLEAR CLARA facilities based at CERN Daresbury laboratory respectively. With ps sub-ps long electron bunches, emitted...
We observe for the first time an effect on driver caused by motion of ions in a plasma wakefield accelerator. The manifests itself as beam tail, which only occurs when sufficient suppresses wakefields. By changing (helium, argon, xenon) experiment, we show that depends inversely ion mass, predicted from theory and simulations. Wakefields are driven resonantly multiple bunches, simulation results indicate ponderomotive force causes ions. In this case, is also expected to depend amplitude...
The CERN Linear Electron Accelerator for Research (CLEAR) has now finished its second year of operation, providing a testbed new accelerator technologies and versatile radiation source. Hosting varied experimental program, this beamline provides flexible test facility users both internal external to CERN, as well being an excellent physics training ground. energy can be between 60 220 MeV, bunch length 1 4 ps, charge in the range 10 pC 2 nC, number bunches 200, at repetition rate 0.8 Hz....
We present recent achievements in the application of optical diffraction radiation (ODR) to measurement transverse beam size a 1.3 GeV micrometer-size electron performed with an instrument installed extended extraction line KEK Accelerator Test Facility. ODR is technique for and emittance highly relativistic particle beams. has advantage being noninvasive relatively inexpensive candidate operation linear accelerators, where no simple alternatives (e.g., synchrotron radiation) are available....
We report on the radiation studies performed at CLEAR facility of CERN in sub-THz range, exploiting picosecond ultrarelativistic electron bunches for production coherent radiation. The radiation, produced by different mechanisms (in particular transition radiation), has been fully characterized using techniques and detectors. main aim that to setup a new beam-based source mm-waves external users, individuating performances limitations. Moreover used longitudinal diagnostics, providing...
We study experimentally the longitudinal and transverse wakefields driven by a highly relativistic proton bunch during self-modulation in plasma. show that wakefields' growth amplitude increase with increasing seed as well charge using maximum radius of distribution measured on screen downstream from externally injecting electrons measuring their final energy. Measurements agree trends predicted theory numerical simulations validate our understanding development self-modulation. Experiments...
Abstract In 2017, AWAKE demonstrated the seeded self-modulation (SSM) of a 400 GeV proton beam from Super Proton Synchrotron at CERN. The angular distribution protons deflected due to SSM is quantitative measure process, which agrees with simulations by two-dimensional (axisymmetric) particle-in-cell code LCODE about 5%. agreement achieved in population scans two selected plasma densities and scan longitudinal density gradient. reached only case wide enough simulation box (several...
We study experimentally the effect of linear plasma density gradients on self-modulation a 400\,GeV proton bunch. Results show that positive/negative gradient in/decreases number micro-bunches and relative charge per micro-bunch observed after 10\,m plasma. The measured modulation frequency also in/decreases. With largest positive we observe two frequencies in power spectrum. are consistent with changes wakefields' phase velocity due to adding slow during growth predicted by theory.
Self-modulation is a beam–plasma instability that useful to drive large-amplitude wakefields with bunches much longer than the plasma skin depth. We present experimental results showing that, when increasing ratio between initial transverse size of bunch and depth, occurs later along bunch, or not at all, over fixed length because amplitude decreases. show cases for which self-modulation does develop, we introduce simple model discussing conditions it would occur after any length. Changing...
Creating extended, highly homogeneous plasma columns like that required by wakefield accelerators can be a challenge. We study the propagation of ultra-short, terawatt power ionizing laser pulses in 10-meter-long rubidium vapor and they create. perform experiments numerical simulations for with 780 nm central wavelength, which is resonant D2 transition from ground state atoms, as well 810 some distance resonances. measure transmitted energy transverse width pulse use schlieren imaging to...
We report the observation of shadowing between two optical transition radiation (OTR) sources from a 205 MeV electron beam. The total intensity is measured as function distance d sources, covering range 0<d<4L_{v}, where L_{v} formation length particles. Data show that starts decreasing due to when approaches until it becomes undetectable for very short distances d/L_{v}→0. A model based solely on interference OTR in good agreement with experimental data. To knowledge authors this first...
The vertical plane transverse emittance of accelerated electron bunches at the AWAKE experiment CERN has been determined, using three different methods data analysis. This is a proof-of-principle measurement existing spectrometer to validate technique. Large values geometric emittance, compared that injection beam, are observed ($\sim \SI{0.5}{\milli\metre\milli\radian}$ with $\sim \SI{0.08}{\milli\metre\milli\radian}$), which in line expectations growth arising from plasma density ramps and...
We describe the implementation of light diagnostics for studying self-modulation instability a long relativistic proton bunch in 10m-long plasma. The wakefields driven by dissipate their energy surrounding amount emitted as atomic line radiation is related to dissipated setup and calibration diagnostics, configured discharge plasma source vapor source. For both sources, we analyze measurements from only (no bunch). show that with source, signal proportional deposited vapor/plasma ionizing...
Plasma wakefield dynamics over timescales up to 800 ps, approximately 100 plasma periods, are studied experimentally at the Advanced Wakefield Experiment (AWAKE). The development of longitudinal amplitude driven by a self-modulated proton bunch is measured using external injection witness electrons that sample fields. In simulation, resonant excitation causes electron trajectory crossing, resulting in potential outside boundary as transversely ejected. Trends consistent with presence this...
We present numerical simulations and experimental results of the self-modulation a long proton bunch in plasma with linear density gradients along beam path. Simulation agree reported [F. Braunmller, T. Nechaeva et al. (AWAKE Collaboration), Phys. Rev. Lett. 125, 264801 (2020)]: negative gradients, charge modulated is lower than positive gradients. In addition, modulation frequency varies gradient. show that dephasing wakefields respect to relativistic protons main cause for loss charge. The...
We outline plans to use plasma light emitted as atomic lines radiation a diagnostic for wakefields driven in by self-modulating, long proton bunch. This is built into the design of new vapor/plasma source that will also allow imposing density step various height at locations. Such few percent relative placed location where self-modulation process grows predicted numerical simulations make bunch drive with GV/m amplitude over hundreds meters plasma.