[Show abstract][Hide abstract] ABSTRACT: The magnetic quadrupole structure formation during the interaction of two
ultra-short high power laser pulses with a collisionless plasma is demonstrated
with 2.5-dimensional particle-in-cell simulations. The subsequent expansion of
the quadrupole is accompanied by magnetic field annihilation in the
ultrarelativistic regime, when the magnetic field can not be sustained by the
plasma current. This results in a dominant contribution of the displacement
current exciting a strong large scale electric?field. This field leads to the
conversion of magnetic energy into kinetic energy of accelerated electrons
inside the thin current sheet.
[Show abstract][Hide abstract] ABSTRACT: The laser driven acceleration of ions is considered a promising candidate for
an ion source for hadron therapy of oncological diseases. Though proton and
carbon ion sources are conventionally used for therapy, other light ions can
also be utilized. Whereas carbon ions require 400 MeV per nucleon to reach the
same penetration depth as 250 MeV protons, helium ions require only 250 MeV per
nucleon, which is the lowest energy per nucleon among the light ions. This fact
along with the larger biological damage to cancer cells achieved by helium
ions, than that by protons, makes this species an interesting candidate for the
laser driven ion source. Two mechanisms (Magnetic Vortex Acceleration and
hole-boring Radiation Pressure Acceleration) of PW-class laser driven ion
acceleration from liquid and gaseous helium targets are studied with the goal
of producing 250 MeV per nucleon helium ion beams that meet the hadron therapy
requirements. We show that He3 ions, having almost the same penetration depth
as He4 with the same energy per nucleon, require less laser power to be
accelerated to the required energy for the hadron therapy.
Physical Review Special Topics - Accelerators and Beams 05/2015; 18(6). DOI:10.1103/PhysRevSTAB.18.061302 · 1.52 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The focusing property of a focal spot of a femtosecond laser pulse is presented under tight focusing conditions (below f-number of 1). The spatial and temporal intensity distributions of a focused electric field are calculated by vector diffraction integrals and coherent superposition method. The validity of the calculation method is examined by comparing the intensity distribution obtained under a high f-number condition to that obtained with the fast Fourier transform method that assumes the scalar paraxial approximation. The spatial and temporal modifications under tight focusing conditions are described for a focused femtosecond laser pulse. The calculation results show that a peak intensity of about 2.5x1024 W/cm2 can be achievable by tightly focusing a 12-fs, 10 PW laser pulse with a f/0.5 parabolic optic. The precise information on intensity distributions of a femtosecond focal spot obtained under a tight focusing condition will be crucial in assessing a focused intensity and in describing the motion of charged particles under an extremely strong electric field in ultra-relativistic and/or relativistic laser matter-interaction studies.
[Show abstract][Hide abstract] ABSTRACT: Within 2017, the ELIMED (ELI-Beamlines MEDical applications) transport beam-line and dosimetric systems for laser-generated beams will be installed at the ELI-Beamlines facility in Prague (CZ), inside the ELIMAIA (ELI Multidisciplinary Applications of laser–Ion Acceleration) interaction room. The beam-line will be composed of two sections: one in vacuum, devoted to the collecting, focusing and energy selection of the primary beam and the second in air, where the ELIMED beam-line dosimetric devices will be located. This paper briefly describes the transport solutions that will be adopted together with the main dosimetric approaches. In particular, the description of an innovative Faraday Cup detector with its preliminary experimental tests will be reported.
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 02/2015; DOI:10.1016/j.nima.2015.02.019 · 1.32 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The ways toward modeling of astrophysical processes and extreme field regimes with super-power lasers are discussed. The main attention is paid to the problem of limited similarity in using the dimensionless parameters characterizing the processes in the laser and astrophysical plasmas. As the most typical examples, we address the magnetic reconnection and collisionless shock waves relevant to the problem of ultrarelativistic particle acceleration. In the extreme field limits we consider the regimes of dominant radiation reaction, changing the electromagnetic wave-matter interaction. In these regimes it, in particular, results in a new powerful source of ultra high-brightness gamma-rays and will make possible electron-positron pair creation in vacuum in a multiphoton processes. This will allow modeling under terrestrial laboratory conditions the processes in astrophysical objects and paves the way to experimental verifications using ultra intense lasers as they are currently developed within the ELI project.
[Show abstract][Hide abstract] ABSTRACT: The paper examines the prospects of using laser plasma as a source of high-energy ions for the purpose of hadron beam therapy an approach which is based on both theory and experimental results (ions are routinely observed to be accelerated in the interaction of high-power laser radiation with matter). Compared to therapy accelerators like synchrotrons and cyclotrons, laser technology is advantageous in that it is more compact and is simpler in delivering ions from the accelerator to the treatment room. Special target designs allow radiation therapy requirements for ion beam quality to be satisfied.
Uspekhi Fizicheskih Nauk 12/2014; 184(12):1265-1298. DOI:10.3367/UFNr.0184.201412a.1265
[Show abstract][Hide abstract] ABSTRACT: The use of a low contrast nanosecond laser pulse with a relatively low intensity (3 × 1016 W cm−2) allowed the enhancing of the yield of induced nuclear reactions in advanced solid targets. In particular the ‘ultraclean’ proton─boron fusion reaction, producing energetic alpha particles without neutron generation, was chosen. A spatially well-defined layer of boron dopants in a hydrogen-enriched silicon substrate was used as a target. A combination of the specific target composition and the laser pulse temporal shape allowed the enhancing of the yield of alpha particles up to 109 per steradian. This result can be ascribed to the interaction of the long-laser pre-pulse with the target and to the optimal target geometry and composition.
[Show abstract][Hide abstract] ABSTRACT: The radiation reaction radically influences the electron motion in an
electromagnetic standing wave formed by two super-intense counter-propagating
laser pulses. Depending on the laser intensity and wavelength, either classical
or quantum mode of radiation reaction prevail, or both are strong. When
radiation reaction dominates, electron motion evolves to limit cycles and
strange attractors. This creates a new framework for high energy physics
experiments on an interaction of energetic charged particle beams and colliding
super-intense laser pulses.
Physics Letters A 12/2014; DOI:10.1016/j.physleta.2015.06.017 · 1.63 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We show that a spatially well-defined layer of boron dopants in a hydrogen-enriched silicon target allows the production of a high yield of alpha particles of around 10^9 per steradian using a nanosecond, low-contrast laser pulse with a nominal intensity of approximately 3×10^16 W/ cm^ −2 . This result can be ascribed to the nature of the long laser-pulse interaction with the target and with the expanding plasma, as well as to the optimal target geometry and composition. The possibility of an impact on future applications such as nuclear fusion without production of neutron-induced radioactivity and compact ion accelerators is anticipated.
Physical Review X 08/2014; 4(3):031030. DOI:10.1103/PhysRevX.4.031030 · 8.39 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Thomson Spectrometers (TPs) are widely used for beam diagnostic as they provide simultaneous information on charge over mass ratio, energy and momentum of detected ions. A new TP design has been realized at INFN-LNS within the LILIA (Laser Induced Light Ion Acceleration) and ELIMED (MEDical application at ELI-Beamlines) projects. This paper reports on the construction details of the TP and on its experimental tests performed at PALS laboratory in Prague, with the ASTERIX IV laser system. Reported data are obtained with polyethylene and polyvinyl alcohol solid targets, they have been compared with data obtained from other detectors. Consistency among results confirms the correct functioning of the new TP. The main features, characterizing the design, are a wide acceptance of the deflection sector and a tunability of the, partially overlapping, magnetic and electric fields that allow to resolve ions with energy up to about 40 MeV for protons.
Journal of Instrumentation 08/2014; 9(08):T08001. DOI:10.1088/1748-0221/9/08/T08001 · 1.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: ELI-Beamlines is one of the four pillars of the ELI (Extreme Light Infrastructure) pan-European project. It will be an ultrahigh-intensity, high repetition-rate, femtosecond laser facility whose main goals are the generation and applications of high-brightness X-ray sources and accelerated charged particles. In particular medical and multidisciplinary applications with laser-accelerated beams are treated by the ELIMED task force, a collaboration between different research institutes. A crucial goal for this network is represented by the design and the realization of a transport beamline able to provide ion beams with suitable characteristics in terms of energy spectrum and angular distribution in order to perform dosimetric tests and biological cell irradiations.
Journal of Instrumentation 05/2014; 9(05):C05065. DOI:10.1088/1748-0221/9/05/C05065 · 1.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: ELI-Beamlines is one of the pillars of the pan-European project ELI (Extreme Light Infrastructure). It will be an ultra high-intensity, high repetition-rate, femtosecond laser facility whose main goal is generation and applications of high-brightness X-ray sources and accelerated charged particles in different fields. Particular care will be devoted to the potential applicability of laser-driven ion beams for medical treatments of tumors. Indeed, such kind of beams show very interesting peculiarities and, moreover, laser-driven based accelerators can really represent a competitive alternative to conventional machines since they are expected to be more compact in size and less expensive. The ELIMED project was launched thanks to a collaboration established between FZU-ASCR (ELI-Beamlines) and INFN-LNS researchers. Several European institutes have already shown a great interest in the project aiming to explore the possibility to use laser-driven ion (mostly proton) beams for several applications with a particular regard for medical ones. To reach the project goal several tasks need to be fulfilled, starting from the optimization of laser-target interaction to dosimetric studies at the irradiation point at the end of a proper designed transport beam-line. Researchers from LNS have already developed and successfully tested a high-dispersive power Thomson Parabola Spectrometer, which is the first prototype of a more performing device to be used within the ELIMED project. Also a Magnetic Selection System able to produce a small pencil beam out of a wide energy distribution of ions produced in laser-target interaction has been realized and some preliminary work for its testing and characterization is in progress. In this contribution the status of the project will be reported together with a short description of the of the features of device recently developed.
Journal of Physics Conference Series 04/2014; 508(1):012010. DOI:10.1088/1742-6596/508/1/012010
[Show abstract][Hide abstract] ABSTRACT: Nowadays, laser-driven proton beams generated by the interaction of high power lasers with solid targets represent a fascinating attraction in the field of the new acceleration techniques. These beams can be potentially accelerated up to hundreds of MeV and, therefore, they can represent a promising opportunity for medical applications. Laser-accelerated proton beams typically show high flux (up to 1011 particles per bunch), very short temporal profile (ps), broad energy spectra and poor reproducibility. In order to overcome these limitations, these beams have be controlled and transported by means of a proper beam handling system. Furthermore, suitable dosimetric diagnostic systems must be developed and tested. In the framework of the ELIMED project, we started to design a dedicated beam transport line and we have developed a first prototype of a beam line key-element: an Energy Selector System (ESS). It is based on permanent dipoles, capable to control and select in energy laser-accelerated proton beams. Monte Carlo simulations and some preliminary experimental tests have been already performed to characterize the device. A calibration of the ESS system with a conventional proton beam will be performed in September at the LNS in Catania. Moreover, an experimental campaign with laser-driven proton beam at the Centre for Plasma Physics, Queens University in Belfast is already scheduled and will be completed within 2014.
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 02/2014; 740. DOI:10.1016/j.nima.2013.10.037 · 1.32 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We present the current status of ELI-Beamlines that will be the Czech pillar of the ELI (Extreme Light Infrastructure) project. The facility will make available high-brightness multi-TW ultrashort laser pulses at kHz repetition rate, 10 Hz repetition rate laser pulses at the petawatt level together with kilojoule nanosecond laser pulses that will be used for generation of 10 PW. These beamlines will be combined to generate X-ray secondary sources, to accelerate electrons, protons and ions and to study dense plasma and high-field frontier physics. These programs will be introduced together with the engineering program necessary for building a users' facility.
Proceedings of SPIE - The International Society for Optical Engineering 01/2014; DOI:10.1117/12.2039165 · 0.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A new type of Faraday cup, capable of detecting high energy charged particles produced in a high intensity laser-matter interaction environment, has recently been developed and demonstrated as a real-time detector based on the time-of-flight technique. An array of these Faraday cups was designed and constructed to cover different observation angles with respect to the target normal direction. Thus, it allows reconstruction of the spatial distribution of ion current density in the subcritical plasma region and the ability to visualise its time evolution through time-of-flight measurements, which cannot be achieved with standard laser optical interferometry. This is a unique method for two-dimensional visualisation of ion currents from laser-generated plasmas. A technical description of the new type of Faraday cup is introduced along with an ad hoc data analysis procedure. Experimental results obtained during campaigns at the Petawatt High-Energy Laser for Heavy Ion Experiments (GSI, Darmstadt) and at the Prague Asterix Laser System (AS CR) are presented. Advantages and limitations of the used diagnostic system are discussed.
The Review of scientific instruments 01/2014; 85(1):013302. DOI:10.1063/1.4859496 · 1.58 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Laser-ion acceleration has recently gained a great interest as an
alternative to conventional and more expensive acceleration techniques.
These ion beams have desirable qualities such as small source size, high
luminosity and small emittance to be used in different fields as Nuclear
Physics, Medical Physics, etc. This is very promising specially for the
future perspective of a new concept of hadrontherapy based on
laser-based devices could be developed, replacing traditional
accelerating machines. Before delivering laser-driven beams for
treatments they have to be handled, cleaned from unwanted particles and
characterized in order to have the clinical requirements. In fact ion
energy spectra have exponential trend, almost 100% energy spread and a
wide angular divergence which is the biggest issue in the beam transport
and, hence, in a wider use of this technology. In order to demonstrate
the clinical applicability of laser-driven beams new collaboration
between ELI-Beamlines project researchers from Prague (Cz) and a
INFN-LNS group from Catania (I) has been already launched and scientists
from different countries have already express their will in joining the
project. This cooperation has been named ELIMED (MEDical application at
ELIBeamlines) and will take place inside the ELI-Beamlines
infrastructure located in Prague. This work describes the schedule of
the ELIMED project and the design of the energy selector which will be
realized at INFN-LNS. The device is an important part of the whole
transport beam line which will be realised in order to make the ion
beams suitable for medical applications.
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 12/2013; 730:174-177. DOI:10.1016/j.nima.2013.05.051 · 1.32 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: ABSTRACT: Laser accelerated proton beams represent nowadays an attractive alternative to the
conventional ones and they have been proposed in different research fields. In particular, the interest
has been focused in the possibility of replacing conventional accelerating machines with
laser-based accelerators in order to develop a new concept of hadrontherapy facilities, which could
result more compact and less expensive. With this background the ELIMED (ELIMED: ELIBeamlines
MEDical applications) research project has been launched by LNS-INFN researchers
(Laboratori Nazionali del Sud-Istituto Nazionale di Fisica Nucleare, Catania, IT) and ASCR-FZU
researchers (Academy of Sciences of the Czech Republic-Fyzik´aln´ı ´ustar, Prague, Cz), within the
�pan-European ELI-Beamlines facility framework. Its main purposes are the demonstration of future
applications in hadrontherapy of optically accelerated protons and the realization of a laseraccelerated
ion transport beamline for multidisciplinary applications. Several challenges, starting
from laser-target interaction and beam transport development, up to dosimetric and radiobiological
issues, need to be overcome in order to reach the final goals. The design and the realization of a
preliminary beam handling and dosimetric system and of an advanced spectrometer for high energy
(multi-MeV) laser-accelerated ion beams will be shortly presented in this work.
13th Topica Seminar on innovative particle and radiation detectors -, Siena (Italy); 10/2013