416 research outputs found
Temperature analysis in the shock waves regime for gas-filled plasma capillaries in plasma-based accelerators
Plasma confinement represents a crucial point for plasma-based accelerators and plasma lenses because it can strongly affect the beam properties. For this reason, an accurate measurement of the plasma parameters, as plasma temperature, pressure and electron density, must be performed. In this paper, we introduce a novel method to detect the plasma temperature and the pressure for gas-filled capillaries in use at the SPARC-LAB test facility. The proposed method is based on the shock waves produced at the ends of the capillary during the gas discharge and the subsequent plasma formation inside it. By measuring the supersonic speed of the plasma outflow, the thermodynamic parameters have been obtained both outside and inside the capillary. A plasma temperature around 1.4 eV has been measured, that depends on the geometric properties and the operating conditions of the capillary
Single-shot non-intercepting profile monitor of plasma-accelerated electron beams with nanometric resolution
An innovative, single-shot, non-intercepting monitor of the transverse profile of plasma-accelerated electron beams is presented, based on the simultaneous measurement of the electron energy and the betatron radiation spectra. The spatial resolution is shown to be down to few tens of nanometers, important for high-precision applications requiring fine shaping of beams and detailed characterizations of the electron transverse phase space at the exit of plasma accelerating structures
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
Focusing of high-brightness electron beams with active-plasma lenses
Plasma-based technology promises a tremendous reduction in size of accelerators used for research, medical, and industrial applications, making it possible to develop tabletop machines accessible for a broader scientific community. By overcoming current limits of conventional accelerators and pushing particles to larger and larger energies, the availability of strong and tunable focusing optics is mandatory also because plasma-accelerated beams usually have large angular divergences. In this regard, active-plasma lenses represent a compact and affordable tool to generate radially symmetric magnetic fields several orders of magnitude larger than conventional quadrupoles and solenoids. However, it has been recently proved that the focusing can be highly nonlinear and induce a dramatic emittance growth. Here, we present experimental results showing how these nonlinearities can be minimized and lensing improved. These achievements represent a major breakthrough toward the miniaturization of next-generation focusing devices
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
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 ~
W/cm 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.Comment: 19 pages, 8 figure
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 show 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 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 ~ 1019 W/cm2 intensity) interacting with thin foil targets. The results can be readily applied to the case of complex stack configurations and to more general experimental conditions
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
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
- …