arXiv subjects

M. P. Anania

Publications and source records attributed to M. P. Anania.

At least 19 recordsLinked to original sources

arXiv2025

Recovery of hydrogen plasma at the sub-nanosecond timescale in a plasma-wakefield accelerator

Plasma wakefield acceleration revolutionized the field of particle accelerators by generating gigavolt-per-centimeter fields. To compete with conventional radio-frequency (RF) accelerators, plasma technology must demonstrate operation at high repetition rates, with a recent research showing feasibility at megahertz levels using an Argon source that recovered after about 60 ns. Here we report about a proof-of-principle experiment that demonstrates the recovery of a Hydrogen plasma at the sub-nanosecond timescale. The result is obtained with a pump-and-probe setup and has been characterized for a wide range of plasma densities. We observed that large plasma densities reestablish their initial state soon after the injection of the pump beam (< 0.7 ns). Conversely, at lower densities we observe the formation of a local dense plasma channel affecting the probe beam dynamics even at long delay times (> 13 ns). The results are supported with numerical simulations and represent a step forward for the next-generation of compact high-repetition rate accelerators.

physics.acc-ph↗

arXiv2022

Design, optimization and experimental characterization of RF injectors for high brightness electron beams and plasma acceleration

In this article, we share our experience related to the new photo-injector commissioning at the SPARC\_LAB test facility. The new photo-injector was installed into an existing machine and our goal was not only to improve the final beam parameters themselves but to improve the machine handling in day-to-day operations as well. Thus, besides the pure beam characterization, this article contains information about the improvements, that were introduced into the new photo-injector design from the machine maintenance point of view, and the benefits, that we gained by using the new technique to assemble the gun itself.

physics.acc-ph↗

arXiv2021

First emittance measurement of the beam-driven plasma wakefield accelerated electron beam

Next-generation plasma-based accelerators can push electron beams to GeV energies within centimetre distances. The plasma, excited by a driver pulse, is indeed able to sustain huge electric fields that can efficiently accelerate a trailing witness bunch, which was experimentally demonstrated on multiple occasions. Thus, the main focus of the current research is being shifted towards achieving a high quality of the beam after the plasma acceleration. In this letter we present beam-driven plasma wakefield acceleration experiment, where initially preformed high-quality witness beam was accelerated inside the plasma and characterized. In this experiment the witness beam quality after the acceleration was maintained on high level, with $0.2\%$ final energy spread and $3.8~μm$ resulting normalized transverse emittance after the acceleration. In this article, for the first time to our knowledge, the emittance of the PWFA beam was directly measured.

physics.acc-ph↗

arXiv2020

Energy spread minimization in a beam-driven plasma wakefield accelerator

Next-generation plasma-based accelerators can push electron bunches to gigaelectronvolt energies within centimetre distances. The plasma, excited by a driver pulse, generates large electric fields that can efficiently accelerate a trailing witness bunch making possible the realization of laboratory-scale applications ranging from high-energy colliders to ultra-bright light sources. So far several experiments have demonstrated a significant acceleration but the resulting beam quality, especially the energy spread, is still far from state of the art conventional accelerators. Here we show the results of a beam-driven plasma acceleration experiment where we used an electron bunch as a driver followed by an ultra-short witness. The experiment demonstrates, for the first time, an innovative method to achieve an ultra-low energy spread of the accelerated witness of about 0.1%. This is an order of magnitude smaller than what has been obtained so far. The result can lead to a major breakthrough toward the optimization of the plasma acceleration process and its implementation in forthcoming compact machines for user-oriented applications.

physics.acc-ph↗

arXiv2020

Accurate spectra for high energy ions by advanced time-of-flight diamond-detector schemes in experiments with high energy and intensity lasers

Time-Of-Flight (TOF) methods are very effective to detect particles accelerated in laser-plasma interactions, but they shows significant limitations when used in experiments with high energy and intensity lasers, where both high-energy ions and remarkable levels of ElectroMagnetic Pulses (EMPs) in the radiofrequency-microwave range are generated. Here we describe a novel advanced diagnostic method for the characterization of protons accelerated by intense matter interactions with high-energy and high-intensity ultra-short laser pulses up to the femtosecond and even future attosecond range. The method employs a stacked diamond detector structure and the TOF technique, featuring high sensitivity, high resolution, high radiation hardness and high signal-to-noise ratio in environments heavily affected by remarkable EMP fields. A detailed study on the use, the optimization and the properties of a single module of the stack is here also described for an experiment where a fast diamond detector is employed in an highly EMP-polluted environment. Accurate calibrated spectra of accelerated protons are presented from an experiment with the femtosecond Flame laser (beyond 100 TW power and ~$10^{19}$ W/cm$^2$ intensity) interacting with thin foil targets. The results that can be readily applied to the case of complex stack configurations and to more general experimental conditions.

physics.ins-det↗

arXiv2019

Longitudinal phase-space manipulation with beam-driven plasma wakefields

The development of compact accelerator facilities providing high-brightness beams is one of the most challenging tasks in field of next-generation compact and cost affordable particle accelerators, to be used in many fields for industrial, medical and research applications. The ability to shape the beam longitudinal phase-space, in particular, plays a key role to achieve high-peak brightness. Here we present a new approach that allows to tune the longitudinal phase-space of a high-brightness beam by means of a plasma wakefields. The electron beam passing through the plasma drives large wakefields that are used to manipulate the time-energy correlation of particles along the beam itself. We experimentally demonstrate that such solution is highly tunable by simply adjusting the density of the plasma and can be used to imprint or remove any correlation onto the beam. This is a fundamental requirement when dealing with largely time-energy correlated beams coming from future plasma accelerators.

physics.acc-ph↗

arXiv2018

Consolidating Multiple FemtoSecond Lasers in Coupled Curved Plasma Capillaries

Consolidating multiple high-energy femtosecond scale lasers is expected to enable implementation of cutting edge research areas varying from wakefield particle accelerators to ultra-high intensity laser pulses for basic fresearch. The ability to guide while augmenting a short-pulse laser is crucial in future laser based TeV particle accelerators where the laser energy depletion is the major setback. We propose, analyze and experimentally demonstrate consolidating multiple femtosecond pulse lasers in coupled curved capillaries. We demonstrate a proof of principle scheme of coupled curved capillaries where two femtosecond laser pulses are combined. We found that the details of the coupling region and injection scheme are crucial to the pulse consolidations. Furthermore, our simulations show that high-intensity short pulse laser can be guided in a small curvature radius capillary. Incorporating these finding in a curved capillary laser coupler will be a significant step towards realization of meters long TeV laser based particle accelerators.

physics.plasm-ph↗

arXiv2018

Evolution of the electric fields induced in high intensity laser-matter interactions

Multi MeV protons \cite{snavely2000intense} and heavier ions are emitted by thin foils irradiated by high-intensity lasers, due to the huge accelerating fields, up to several teraelectronvolt per meter, at sub-picosecond timescale \cite{dubois2014target}. The evolution of these huge fields is not well understood till today. Here we report, for the first time, direct and temporally resolved measurements of the electric fields produced by the interaction of a short-pulse high-intensity laser with solid targets. The results, obtained with a sub-$100$ fs temporal diagnostics, show that such fields build-up in few hundreds of femtoseconds and lasts after several picoseconds.

physics.plasm-ph↗

arXiv2018

Plasma ramps caused by outflow in gas-filled capillaries

Plasma confinement inside capillaries has been developed in the past years for plasma-based acceleration to ensure a stable and repeatable plasma density distribution during the interaction with either particles or laser beams. In particular, gas-filled capillaries allow a stable and almost predictable plasma distribution along the interaction with the particles. However, the plasma ejected through the ends of the capillary interacts with the beam before the inner plasma, affecting the quality of the beam. In this article we report the measurements on the evolution of the plasma flow at the two ends of a 1 cm long, 1 mm diameter capillary filled with hydrogen. In particular, we measured the longitudinal density distribution and the expansion velocity of the plasma outside the capillary. This study will allow a better understanding of the beam-plasma interaction for future plasma-based experiments.

physics.acc-ph↗

arXiv2018

Conceptual design of electron beam diagnostics for high brightness plasma accelerator

A design study of the diagnostics of a high brightness linac, based on X-band structures, and a plasma accelerator stage, has been delivered in the framework of the EuPRAXIA@SPARC_LAB project. In this paper, we present a conceptual design of the proposed diagnostics, using state of the art systems and new and under development devices. Single shot measurements are preferable for plasma accelerated beams, including emittance, while $μ$m level and fs scale beam size and bunch length respectively are requested. The needed to separate the driver pulse (both laser or beam) from the witness accelerated bunch imposes additional constrains for the diagnostics. We plan to use betatron radiation for the emittance measurement just at the end of the plasma booster, while other single-shot methods must be proven before to be implemented. Longitudinal measurements, being in any case not trivial for the fs level bunch length, seem to have already a wider range of possibilities.

physics.acc-ph↗

arXiv2018

Recent studies on single-shot diagnostics for plasma accelerators at SPARC_LAB

Plasma wakefield acceleration is the most promising acceleration technique for compact and cheap accelerators, thanks to the high accelerating gradients achievable. Nevertheless, this approach still suffers of shot-to-shot instabilities, mostly related to experimental parameters fluctuations. Therefore, the use of single shot diagnostics is needed to properly understand the acceleration mechanism. In this work, we present two diagnostics to probe electron beams from laser-plasma interactions, one relying on Electro Optical Sampling (EOS) for laser-solid matter interactions, the other one based on Optical Transition Radiation (OTR) for single shot measurements of the transverse emittance of plasma accelerated electron beams, both developed at the SPARC_LAB Test Facility.

physics.plasm-ph↗

arXiv2018

Characterization of self-injected electron beams from LWFA experiments at SPARC_LAB

The plasma-based acceleration is an encouraging technique to overcome the limits of the accelerating gradient in the conventional RF acceleration. A plasma accelerator is able to provide accelerating fields up to hundreds of $GeV/m$, paving the way to accelerate particles to several MeV over a short distance (below the millimetre range). Here the characteristics of preliminary electron beams obtained with the self-injection mechanism produced with the FLAME high-power laser at the SPARC_LAB test facility are shown. In detail, with an energy laser on focus of $1.5\ J$ and a pulse temporal length (FWHM) of $40\ fs$, we obtained an electron plasma density due to laser ionization of about $6 \times 10^{18}\ cm^{-3}$, electron energy up to $350\ MeV$ and beam charge in the range $(50 - 100)\ pC$.

physics.acc-ph↗

arXiv2018

Overview of Plasma Lens Experiments and Recent Results at SPARC_LAB

Beam injection and extraction from a plasma module is still one of the crucial aspects to solve in order to produce high quality electron beams with a plasma accelerator. Proper matching conditions require to focus the incoming high brightness beam down to few microns size and to capture a high divergent beam at the exit without loss of beam quality. Plasma-based lenses have proven to provide focusing gradients of the order of kT/m with radially symmetric focusing thus promising compact and affordable alternative to permanent magnets in the design of transport lines. In this paper an overview of recent experiments and future perspectives of plasma lenses is reported.

physics.acc-ph↗

arXiv2018

The FLAME laser at SPARC_LAB

FLAME is a high power laser system installed at the SPARC_LAB Test Facility in Frascati (Italy). The ultra-intense laser pulses are employed to study the interaction with matter for many purposes: electron acceleration through LWFA, ion and proton generation exploiting the TNSA mechanism, study of new radiation sources and development of new electron diagnostics. In this work, an overview of the FLAME laser system will be given, together with recent experimental results

physics.acc-ph↗

arXiv2018

EuPRAXIA@SPARC_LAB Design study towards a compact FEL facility at LNF

On the wake of the results obtained so far at the SPARC\_LAB test-facility at the Laboratori Nazionali di Frascati (Italy), we are currently investigating the possibility to design and build a new multi-disciplinary user-facility, equipped with a soft X-ray Free Electron Laser (FEL) driven by a $\sim$1 GeV high brightness linac based on plasma accelerator modules. This design study is performed in synergy with the EuPRAXIA design study. In this paper we report about the recent progresses in the on going design study of the new facility.

physics.acc-ph↗

arXiv2018

Recent results at SPARC_LAB

The current activity of the SPARC_LAB test-facility is focused on the realization of plasma-based acceleration experiments with the aim to provide accelerating field of the order of several GV/m while maintaining the overall quality (in terms of energy spread and emittance) of the accelerated electron bunch. In the following, the current status of such an activity is presented. We also show results related to the usability of plasmas as focusing lenses in view of a complete plasma-based focusing and accelerating system.

physics.acc-ph↗

arXiv2018

Wake fields effects in dielectric capillary

Plasma wake-field acceleration experiments are performed at the SPARC LAB test facility by using a gas-filled capillary plasma source composed of a dielectric capillary. The electron can reach GeV energy in a few centimeters, with an accelerating gradient orders of magnitude larger than provided by conventional techniques. In this acceleration scheme, wake fields produced by passing electron beams through dielectric structures can determine a strong beam instability that represents an important hurdle towards the capability to focus high-current electron beams in the transverse plane. For these reasons, the estimation of the transverse wakefield amplitudes assumes a fundamental role in the implementation of the plasma wake-field acceleration. In this work, it presented a study to investigate which parameters affect the wake-field formation inside a cylindrical dielectric structure, both the capillary dimensions and the beam parameters, and it is introduced a quantitative evaluation of the longitudinal and transverse electric fields.

physics.acc-ph↗

arXiv2018

Nano-machining, surface analysis and emittance measurements of a copper photocathode at SPARC_LAB

R\&D activity on Cu photocathodes is under development at the SPARC\_LAB test facility to fully characterize each stage of the photocathode "life" and to have a complete overview of the photoemission properties in high brightness photo-injectors. The nano(n)-machining process presented here consists in diamond milling, and blowing with dry nitrogen. This procedure reduces the roughness of the cathode surface and prevents surface contamination introduced by other techniques, such as polishing with diamond paste or the machining with oil. Both high roughness and surface contamination cause an increase of intrinsic emittance and consequently a reduction of the overall electron beam brightness. To quantify these effects, we have characterized the photocathode surface in terms of roughness measurement, and morphology and chemical composition analysis by means of Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), and Atomic Force Microscopy (AFM) techniques. The effects of n-machining on the electron beam quality have been also investigated through emittance measurements before and after the surface processing technique. Finally, we present preliminary emittance studies of yttrium thin film on Cu photocathodes.

physics.acc-ph↗