Driven Plasma Wakefield Acceleration Experiment Research Articles

EARLI: design of a laser wakefield accelerator for AWAKE

Following the successful Run 1 experiment, the Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) Run2 experiment requires the design and implementation of a compact electron source. The “high-quality Electron Accelerator driven by a Reliable Laser wakefield for Industrial uses” (EARLI) project aims to design a stand-alone high-quality electron injector based on a laser wakefield accelerator (LWFA) as an alternative proposal to AWAKE’s baseline design of an X-band electron gun. This project is currently in the design phase, including simulations and experimental tests. Exhaustive beam physics studies for conventional accelerators are applied to LWFA physics.

Online multi-objective particle accelerator optimization of the AWAKE electron beam line for simultaneous emittance and orbit control

Multi-objective optimization is important for particle accelerators where various competing objectives must be satisfied routinely such as, for example, transverse emittance vs bunch length. We develop and demonstrate an online multi-time scale multi-objective optimization algorithm that performs real time feedback on particle accelerators. We demonstrate the ability to simultaneously minimize the emittance and maintain a reference trajectory of a beam in the electron beamline in CERN’s Advanced Proton Driven Plasma Wakefield Acceleration Experiment.

First fully kinetic three-dimensional simulation of the AWAKE baseline scenario

The ‘Advanced Proton Driven Plasma Wakefield Acceleration Experiment’ (AWAKE) aims to accelerate leptons via proton-beam-driven wakefield acceleration. It comprises extensive numerical studies as well as experiments at the CERN laboratory. The baseline scenario incorporates a plasma volume of approximately 62 cm3. The plasma wavelength is about 1.25 mm and needs to be adequately resolved, using a minimum of 130 points per plasma wavelength, in order to accurately reproduce the physics. The baseline scenario incorporates the proton beam micro-bunching, the concurrent nonlinear wakefield growth as well as the off-axis electron beam injection, trapping and acceleration. We present results for the first three-dimensional simulation of this baseline scenario with a full model, using a sufficient resolution. The simulation consumed about 22 Mch of computer resources and scaled up to 32 768 cores, thanks to a multitude of adaptions, improvements and optimization of the simulation code PSC. Through this large-scale simulation effort we were able to verify the results of reduced-model simulations as well as identify important novel effects during the electron injection process.

Commissioning of beam instrumentation at the CERN AWAKE facility after integration of the electron beam line

The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) is a project at CERN aiming to accelerate an electron bunch in a plasma wakefield driven by a proton bunch. The plasma is induced in a 10 m long rubidium vapor cell using a pulsed Ti:Sapphire laser, with the wakefield formed by a proton bunch from the CERN Super Proton Synchrotron (SPS). A 16 MeV electron bunch is simultaneously injected into the plasma cell to be accelerated by the wakefield to energies in the GeV range over this short distance. After successful runs with the proton and laser beams, the electron beam line was installed and commissioned at the end of 2017 to produce and inject a suitable electron bunch into the plasma cell. To achieve the goals of the experiment, it is important to have reliable beam instrumentation measuring the various parameters of the proton, electron and laser beams. This contribution presents the status of the beam instrumentation in AWAKE and reports on the performance achieved during the AWAKE runs in 2017.

Physics at the SPS.

The CERN Super Proton Synchrotron (SPS) has delivered a variety of beams to a vigorous fixed target physics program since 1978. In this paper, we restrict ourselves to the description of a few illustrative examples in the ongoing physics program at the SPS. We will outline the physics aims of the COmmon Muon Proton Apparatus for Structure and Spectroscopy (COMPASS), north area 64 (NA64), north area 62 (NA62), north area 61 (NA61), and advanced proton driven plasma wakefield acceleration experiment (AWAKE). COMPASS studies the structure of the proton and more specifically of its spin. NA64 searches for the dark photon A', which is the messenger for interactions between normal and dark matter. The NA62 experiment aims at a 10% precision measurement of the very rare decay K+ → π+νν. As this decay mode can be calculated very precisely in the Standard Model, it offers a very good opportunity to look for new physics beyond the Standard Model. The NA61/SHINE experiment studies the phase transition to Quark Gluon Plasma, a state in which the quarks and gluons that form the proton and the neutron are de-confined. Finally, AWAKE investigates proton-driven wake field acceleration: a promising technique to accelerate electrons with very high accelerating gradients. The Physics Beyond Colliders study at CERN is paving the way for a significant and diversified continuation of this already rich and compelling physics program that is complementary to the one at the big colliders like the Large Hadron Collider.

The electron accelerators for the AWAKE experiment at CERN—Baseline and Future Developments

The AWAKE collaboration prepares a proton driven plasma wakefield acceleration experiment using the SPS beam at CERN. A long proton bunch extracted from the SPS interacts with a high power laser and a 10 m long rubidium vapor plasma cell to create strong wakefields allowing sustained electron acceleration. The electron beam to probe these wakefields is created by an electron accelerator consisting of an rf-gun and a booster structure. This electron source should provide beams with intensities between 0.1 and 1 nC, bunch lengths between 0.3 and 3 ps and an emittance of the order of 2 mm mrad. The booster structure should accelerate the electrons to 16 MeV. The electron line includes a series of diagnostics (pepper-pot, BPMs, spectrometer, Faraday cup and screens) and an optical transfer line merges the electron beam with the proton beam on the same axis. The installation of the electron line started in early 2017 and the commissioning will take place at the end of 2017. The first phase of operation is called RUN1. After the long shutdown of LHC a second phase for AWAKE is planned starting 2021 called RUN2. In this phase the aim is to demonstrate the acceleration of high quality electron beams therefore a bunch length of the order of 100 fs rms is required corresponding to a fraction of the plasma wavelength. The AWAKE collaboration is studying the design of such an injector either based on classical rf-gun injectors or on laser wake-field acceleration. The focus for the RF accelerator is on a hybrid design using an S-band rf-gun and x-band bunching and acceleration cavities. The layout of the current and the future electron accelerator and transfer line, including the diagnostics will be presented.

AWAKE, The Advanced Proton Driven Plasma Wakefield Acceleration Experiment at CERN

The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plasma wakefield generation and electron acceleration driven by proton bunches. It is a proof-of-principle R&D experiment at CERN and the world׳s first proton driven plasma wakefield acceleration experiment. The AWAKE experiment will be installed in the former CNGS facility and uses the 400GeV/c proton beam bunches from the SPS. The first experiments will focus on the self-modulation instability of the long (rms ~12cm) proton bunch in the plasma. These experiments are planned for the end of 2016. Later, in 2017/2018, low energy (~15MeV) electrons will be externally injected into the sample wakefields and be accelerated beyond 1GeV. The main goals of the experiment will be summarized. A summary of the AWAKE design and construction status will be presented.

The electron accelerator for the AWAKE experiment at CERN

The AWAKE collaboration prepares a proton driven plasma wakefield acceleration experiment using the SPS beam at CERN. A long proton bunch extracted from the SPS interacts with a high power laser and a 10m long rubidium vapour plasma cell to create strong wakefields allowing sustained electron acceleration. The electron bunch to probe these wakefields is supplied by a 20MeV electron accelerator. The electron accelerator consists of an RF-gun and a short booster structure. This electron source should provide beams with intensities between 0.1 and 1nC, bunch lengths between 0.3 and 3ps and an emittance of the order of 2mm mrad. The wide range of parameters should cope with the uncertainties and future prospects of the planned experiments. The layout of the electron accelerator, its instrumentation and beam dynamics simulations are presented.

Beam studies and experimental facility for the AWAKE experiment at CERN

A Proton Driven Plasma Wakefield Acceleration Experiment has been proposed as an approach to eventually accelerate an electron beam to the TeV energy range in a single plasma section. To verify this novel technique, a proof of principle R&D experiment, AWAKE, is planned at CERN using 400GeV proton bunches from the SPS. An electron beam will be injected into the plasma cell to probe the accelerating wakefield. The AWAKE experiment will be installed in the CNGS facility profiting from existing infrastructure where only minor modifications need to be foreseen. The design of the experimental area and the proton and electron beam lines are shown. The achievable SPS proton bunch properties and their reproducibility have been measured and are presented.