arXiv subjects

D. Margarone

Publications and source records attributed to D. Margarone.

16 recordsLinked to original sources

arXiv2026

Relative and absolute dosimetric commissioning of the ELIMAIA--ELIMED laser-driven proton beamline at 23.4 MeV

The development of laser-driven proton beamlines for biomedical and radiobiological applications requires traceable dosimetry and reliable online monitoring at the irradiation point. In this work, we report the relative and absolute dosimetric commissioning of the ELIMAIA--ELIMED laser-driven proton beamline at ELI Beamlines using an energy-selected proton beam with an average energy of about 24~MeV. Radiochromic-film measurements were used to characterize the transverse dose distribution, the depth--dose profile, and the proton energy spectrum at the irradiation point. The reconstructed spectrum was centred at $23.45~\mathrm{MeV}$ with a FWHM of $2.60~\mathrm{MeV}$, while the transverse dose distribution showed an approximately $5.5~\mathrm{mm}$ field size with a millimetre-scale homogeneous region. The Faraday Cup was used as the absolute reference detector for dose to water determination and for cross-calibrating the Dual-Gap Ionization Chamber, which was operated as the primary online dose monitor. The Integrating Current Transformer and Secondary Electron Monitor were evaluated as upstream relative beam monitors. An independent RCF--FC dose comparison performed over fifty consecutive shots yielded $30.45 \pm 3.5~\mathrm{cGy}$ from the FC and $36.46 \pm 1.8~\mathrm{cGy}$ from the EBT3 film. Dedicated G4ELIMED Monte Carlo simulations showed that the RCF positioned upstream of the FC perturbs the FC measurement through proton losses outside the FC acceptance and through an increase in the effective beam area at the FC entrance. Applying the resulting correction factor, $C_{\mathrm{MC}}=1.109$, reduced the residual difference between the FC- and RCF-derived doses to about $7\%$. These results establish the dosimetric chain of the ELIMAIA--ELIMED beamline under the present low-fluence commissioning conditions and identify the operational limits of the online monitoring system.

physics.acc-ph↗

arXiv2025

Characterization and automated optimization of laser-driven proton beams from converging liquid sheet jet targets

Compact, stable, and versatile laser-driven ion sources hold great promise for applications ranging from medicine to materials science and fundamental physics. While single-shot sources have demonstrated favorable beam properties, including the peak fluxes necessary for several applications, high repetition rate operation will be necessary to generate and sustain the high average flux needed for many of the most exciting applications of laser-driven ion sources. Further, to navigate through the high-dimensional space of laser and target parameters towards experimental optima, it is essential to develop ion acceleration platforms compatible with machine learning learning techniques and capable of autonomous real-time optimization. Here we present a multi-Hz ion acceleration platform employing a liquid sheet jet target. We characterize the laser-plasma interaction and the laser-driven proton beam across a variety of key parameters governing the interaction using an extensive suite of online diagnostics. We also demonstrate real-time, closed-loop optimization of the ion beam maximum energy by tuning the laser wavefront using a Bayesian optimization scheme. This approach increased the maximum proton energy by 11% compared to a manually-optimized wavefront by enhancing the energy concentration within the laser focal spot, demonstrating the potential for closed-loop optimization schemes to tune future ion accelerators for robust high repetition rate operation.

physics.plasm-ph↗

arXiv2024

Laser initiated p-11B fusion reactions in petawatt high-repetition-rates laser facilities

Driving the nuclear fusion reaction p+11B -> 3 alpha + 8.7 MeV in laboratory conditions, by interaction between high-power laser pulses and matter, has become a popular field of research, due to numerous applications that it can potentially allow: an alternative to deuterium-tritium (DT) for fusion energy production, astrophysics studies and alpha-particle generation for medical treatments. A possible scheme for laser-driven p-11B reactions is to direct a beam of laser-accelerated protons onto a boron sample (the so-called 'pitcher-catcher' scheme). This technique was successfully implemented on large, energetic lasers, yielding hundreds of joules per shot at low repetition. We present here a complementary approach, exploiting the high-repetition rate of the VEGA III petawatt laser at CLPU (Spain), aiming at accumulating results from many interactions at much lower energy, for better controlling the parameters and the statistics of the measurements. Despite a moderate energy per pulse, our experiment allowed exploring the laser-driven fusion process with tens (up to hundreds) of laser shots. The experiment provided a clear signature of the produced reactions and of the fusion products, accumulated over many shots, leading to an improved optimization of the diagnostic for these experimental campaigns In this paper we discuss the effectiveness of the laser-driven p-11B fusion in the pitcher-catcher scheme, at high-repetition rate, addressing the challenges of this experimental scheme and highlighting its critical aspects. Our proposed methodologies allow evaluating the performance of this scheme for laser-driven alpha particle production and can be adapted to high-repetition rate laser facilities with higher energy and intensity.

physics.plasm-ph↗

arXiv2024

Demonstration of The Brightest Nano-size Gamma Source

Gamma rays selectively interact with nuclei, induce and mediate nuclear reactions and elementary particle interactions, and exceed x-rays in penetrating power and thus are indispensable for analysis and modification of dense objects. Yet, the available gamma sources lack sufficient power and brightness. The predicted and highly desirable laser-driven gamma flash, from here on termed "Gamma Flash", based on inverse Compton scattering from solid targets at extreme irradiances (>$10^{23}W/cm^2$), would be the highest-power and the brightest terrestrial gamma source with a 30-40% laser-to-gamma energy conversion. However, Gamma Flash remains inaccessible experimentally due to the Bremsstrahlung background. Here we experimentally demonstrate a new interaction regime at the highest effective irradiance where Gamma Flash scaled quickly with the laser power and produced several times the number of Bremsstrahlung photons. Simulations revealed an attosecond, Terawatt Gamma Flash with a nanometre source size achieving a record brightness exceeding $~10^{23}photons/mm^2mrad^2s$ per 0.1% bandwidth at tens of MeV photon energies, surpassing astrophysical Gamma Ray Bursts. These findings could revolutionize inertial fusion energy by enabling unprecedented sub-micrometre/femtosecond resolution radiography of fuel mixing instabilities in extremely-compressed targets. The new gamma source could facilitate significant advances in time-resolved nuclear physics, homeland security, nuclear waste management and non-proliferation, while opening possibilities for spatially-coherent gamma rays.

physics.plasm-ph↗

arXiv2023

Radioisotopes production using lasers: from basic science to applications

Laser technologies improved after the understanding of the Chirped Pulse Amplification (CPA) which allows energetic laser beams to be compressed to tens of femtosecond (fs) pulse durations and focused to few $\mu$m. Protons of tens of MeV can be accelerated using for instance the Target Normal Sheath Acceleration (TNSA) method and focused on secondary targets. In such conditions, nuclear reactions can occur and radioisotopes relevant for medical purposes be produced. High repetition lasers can be used to produce enough isotopes for medical applications. This route is competitive to conventional methods mostly based on accelerators. In this paper we study the production of $^{67}$Cu, $^{63}$Zn, $^{18}$F and $^{11}$C currently used in positron emission tomography (PET) and other applications. At the same time, we study the reaction $^{10}$B(p,$\alpha$)$^{7}$Be and $^{70}$Zn(p,4n)$^{67}$Ga to put further constraints to the proton distributions at different angles and to the reaction $^{11}$B(p,$\alpha$)$^{8}$Be relevant for energy production. The experiment was performed at the 1 petawatt (PW) laser facility at Vega III located in Salamanca-Spain. Angular distributions of radioisotopes in the forward (with respect to the laser direction) and backward directions were measured using a High Purity Germanium Detector (HPGE). Our results are reasonably reproduced by the numerical estimates following the approach of Kimura et al. (NIMA637(2011)167)

nucl-ex↗

arXiv2023

Automated control and optimisation of laser driven ion acceleration

The interaction of relativistically intense lasers with opaque targets represents a highly non-linear, multi-dimensional parameter space. This limits the utility of sequential 1D scanning of experimental parameters for the optimisation of secondary radiation, although to-date this has been the accepted methodology due to low data acquisition rates. High repetition-rate (HRR) lasers augmented by machine learning present a valuable opportunity for efficient source optimisation. Here, an automated, HRR-compatible system produced high fidelity parameter scans, revealing the influence of laser intensity on target pre-heating and proton generation. A closed-loop Bayesian optimisation of maximum proton energy, through control of the laser wavefront and target position, produced proton beams with equivalent maximum energy to manually-optimized laser pulses but using only 60% of the laser energy. This demonstration of automated optimisation of laser-driven proton beams is a crucial step towards deeper physical insight and the construction of future radiation sources.

physics.plasm-ph↗

arXiv2022

Design of the ELIMAIA ion collection system

A system of permanent magnet quadrupoles (PMQs) is going to be realized by INFNLNS to be used as a collection system for the injection of laser driven ion beams up to 60 AMeV in an energy selector based on four resistive dipoles. This system is the first element of the ELIMED (ELI-Beamlines MEDical and Multidisciplinary applications) beam transport, dosimetry and irradiation line that will be developed by INFN-LNS (It) and installed at the ELI-Beamlines facility in Prague (Cz). ELIMED will be the first users open transport beam-line where a controlled laser-driven ion beam will be used for multidisciplinary researches. The definition of well specified characteristics, both in terms of performances and field quality, of the magnetic lenses is crucial for the system realization, for the accurate study of the beam dynamics and for the proper matching with the magnetic selection system which will be designed in the next months. Here, we report the design of the collection system and the adopted solutions in order to realize a robust system form the magnetic point of view. Moreover, the first preliminary transport simulations are also described.

physics.acc-ph↗

arXiv2018

A new energy spectrum reconstruction method for Time-Of-Flight diagnostics of high-energy laser-driven protons

The Time-of-Flight (ToF) technique coupled with semiconductor-like detectors, as silicon carbide and diamond, is one of the most promising diagnostic methods for high-energy, high repetition rate, laser-accelerated ions allowing a full on-line beam spectral characterization. A new analysis method for reconstructing the energy spectrum of high-energy laser-driven ion beams from TOF signals is hereby presented and discussed. The proposed method takes into account the detector's working principle, through the accurate calculation of the energy loss in the detector active layer, using Monte Carlo simulations. The analysis method was validated against well-established diagnostics, such as the Thomson Parabola Spectrometer, during an experimental campaign carried out at the Rutherford Appleton Laboratory (RAL, UK) with the high-energy laser-driven protons accelerated by the VULCAN Petawatt laser.

physics.acc-ph↗

arXiv2018

Discussing the discrepancy between analytical calculations and the observed biological effectiveness in proton boron capture therapy (pbct)

A work recently published experimentally demonstrates an increase in the radiobiological efficacy of clinical proton beams when a tumour is treated in the presence of a concentration of 11B. The paper, for the first time, demonstrates the potential role of the p+11B to 3α (for brevity, p-B) reaction in the biological enhancement of proton therapy effectiveness. The work reports robust experimental data in terms of clonogenic cell survival and chromosomal aberrations and unambiguously shows the presence of an enhancement when cells were exposed to a clinical proton beam subject to treatment with sodium boroncaptate (BSH). Moreover, the greater occurrence of complex-type chromosomal exchanges points to the effect as due radiation of a LET (Linear Energy Transfer) greater than that of protons alone, possibly the alpha particles generated by the reaction. At the same time, we emphasized that analytical calculations, performed on the basis of the well-known total production cross section data, are not able to explain the effect in a macroscopic way, i.e. solely in terms of a trivial increase in the total dose released in the cells by the alpha-particles. In this paper, thanks to simulations and analytical calculations, we will discuss the theoretically expected alpha particle yield and the corresponding LET and RBE (Relative Biological Effectiveness) increase related to the 11B presence. We conclude that a mere calculation based on the classical concepts of integral Dose, and average LET and RBE cannot be used to justify the observed radiobiological phenomena. We, therefore, suggest that micro- and nano-dosimetric aspects must be taken into account.

physics.med-ph↗

arXiv2018

Response to the authors of 'On the (un)effectiveness of Proton Boron Capture in Proton Therapy'

This manuscript provides a response to a recent report by Mazzone et al. available online on arXiv that, in turn, tentatively aims at demonstrating the inefficacy of proton boron capture in hadrotherapy. We clarify that Mazzone et al. do not add any scientific or technical insights to the points extensively discussed in the original manuscript by Cirrone et al., and/or in the series of iterations had with the Referee, which ultimately lead to the publication of our original and pioneering experimental work. Here we summarize some of the key points of the long scientific debate we had during the review process of paper by Cirrone et al., which are very similar to the considerations presented by Mazzone et al.. In conclusion, no quantitative explanation of our robust experimental achievements presented in Cirrone et al. is provided in Mazzone et al.

physics.med-ph↗

arXiv2018

Geant4 simulation of the ELIMED transport and dosimetry beam line for high-energy laser-driven ion beam multidisciplinary applications

The ELIMED (MEDical and multidisciplinary application at ELI Beamlines) beam line is being developed at INFN-LNS with the aim of transporting and selecting in energy proton and ion beams accelerated by laser-matter interaction at ELI Beamlines in Prague. It will be a section of the ELIMAIA (ELI Multidisciplinary Applications of laser-Ions Acceleration) beam line, dedicated to applications, including the medical one, of laser-accelerated ion beams [1,2]. A Monte Carlo model has been developed to support the design of the beam line in terms of particle transport efficiency, to optimize the transport parameters at the irradiation point in air and, furthermore, to predict beam parameters in order to deliver dose distributions of clinical relevance. The application has been developed using the Geant4 [3] Monte Carlo toolkit and has been designed in a modular way in order to easily switch on/off geometrical components according to different experimental setups and users requirements, as reported in [4], describing the early-stage code and simulations. The application has been delivered to ELI Beamlines and will be available for future ELIMAIA's users as ready-to-use tool useful during experiment preparation and analysis. The final version of the developed application will be described in detail in this contribution, together with the final results, in terms of energy spectra and transmission efficiency along the in-vacuum beam line, obtained by performing end-to-end simulations.

physics.acc-ph↗

arXiv2017

On production and asymmetric focusing of flat electron beams using rectangular capillary discharge plasmas

A method for the asymmetric focusing of electron bunches, based on the active plasma lensing technique is proposed. This method takes advantage of the strong inhomogeneous magnetic field generated inside the capillary discharge plasma to focus the ultrarelativistic electrons. The plasma and magnetic field parameters inside the capillary discharge are described theoretically and modeled with dissipative magnetohydrodynamic computer simulations enabling analysis of the capillaries of rectangle cross-sections. Large aspect ratio rectangular capillaries might be used to transport electron beams with high emittance asymmetries, as well as assist in forming spatially flat electron bunches for final focusing before the interaction point.

physics.plasm-ph↗

arXiv2016

Prompt gamma ray diagnostics and enhanced hadron-therapy using neutron-free nuclear reactions

We propose a series of simulations about the potential use of Boron isotopes to trigger neutron-free (aneutronic) nuclear reactions in cancer cells through the interaction with an incoming energetic proton beam, thus resulting in the emission of characteristic prompt gamma radiation (429 keV, 718 keV and 1435 keV). Furthermore assuming that the Boron isotopes are absorbed in cancer cells, the three alpha-particles produced in each p-11B aneutronic nuclear fusion reactions can potentially result in the enhancement of the biological dose absorbed in the tumor region since these multi-MeV alpha-particles are stopped inside the single cancer cell, thus allowing to spare the surrounding tissues. Although a similar approach based on the use of 11B nuclei has been proposed in [1], our work demonstrate, using Monte Carlo simulations, the crucial importance of the use of 10B nuclei (in a solution containing also 11B) for the generation of prompt gamma-rays, which can be applied to medical imaging. In fact, we demonstrate that the use of 10B nuclei can enhance the intensity of the 718 keV gamma-ray peak more than 30 times compared to the solution containing only 11B nuclei. A detailed explanation of the origin of the different prompt gamma-rays, as well as of their application as real-time diagnostics during a potential cancer treatment, is here discussed.

physics.med-ph↗

arXiv2016

Avalanche boron fusion by laser picosecond block ignition with magnetic trapping for clean and economic reactor

After the very long consideration of the ideal energy source by fusion of the protons of light hydrogen with the boron isotope 11 (boron fusion HB11) the very first two independent measurements of very high reaction gains by lasers basically opens a fundamental breakthrough. The non-thermal plasma block ignition with extremely high power laser pulses above petawatt of picosecond duration in combination with up to ten kilotesla magnetic fields for trapping has to be combined to use the measured high gains as proof of an avalanche reaction for an environmentally clean, low cost and lasting energy source as potential option against global warming. The unique HB11 avalanche reaction is are now based on elastic collisions of helium nuclei (alpha particles) limited only to a reactor for controlled fusion energy during a very short time within a very small volume.

physics.plasm-ph↗

arXiv2015

Picosecond-petawatt laser-block ignition of avalanche boron fusion by ultrahigh acceleration and ultrahigh magnetic fields

Fusion energy from reacting hydrogen (protons) with the boron isotope 11 (HB11) resulting in three stable helium nuclei, is without problem of nuclear radiation in contrast to DT fusion. But the HB11 reaction driven by nanosecond laser pulses with thermal compression and ignition by lasers is extremely difficult. This changed radically when irradiation with picosecond laser pulses produces a non-thermal plasma block ignition with ultrahigh acceleration. This uses the nonlinear (ponderomotive) force to surprisingly resulting in same thresholds as DT fusion even under pessimistic assumption of binary reactions. After evaluation of reactions trapped cylindrically by kilotesla magnetic fields and using the measured highly increased HB11 fusion gains for the proof of an avalanche of the three alphas in secondary reactions, possibilities for an absolutely clean energy source at competitive costs were concluded.

physics.plasm-ph↗

arXiv2015

Helium-3 and Helium-4 acceleration by high power laser pulses for hadron therapy

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.

physics.plasm-ph↗