A novel scheme for generating powerful terahertz (THz) radiation based on laser-solid interactions is proposed. When a $p$-polarized femtosecond laser impinges obliquely on a plane solid target and the target partially blocks the laser energy, surface electrons are extracted out and accelerated by the laser fields, forming a low-divergence electron beam. A half-cycle THz radiation pulse is emitted simultaneously as the beam passes by the edge of the target, due to coherent diffraction radiation. Our particle-in-cell simulations show that the relativistic THz pulse can have an energy of a few tens of millijoule and the conversion efficiency can be over 1$\%$ with existing $\sim$J level femtosecond laser sources.
Coherent transition radiation (CTR) from relativistic electron beam interaction with an overdense plasma foil is investigated by making use of two-dimensional particle-in-cell simulations. Well-defined single electron beam either of uniform profile or having substructures is considered for various beam-plasma parameters. The main purpose is to mimic the complicated beam-plasma conditions that is often found, for example, in intense laser plasma interactions. Key properties of the CTR concerning their temporal, angular and spectral profiles are identified. Several saturation effects due to the …
We investigate the generation of twin $γ$ ray beams in collision of an ultrahigh intensity laser pulse with a laser wakefield accelerated electron beam by using particle-in-cell simulation. We consider the composed target of a homogeneous underdense preplasma in front of an ultrathin solid foil. The electrons in the preplasma are trapped and accelerated by the wakefield. When the laser pulse is reflected by the thin solid foil, the wakefield accelerated electrons continue to move forward and passing through the foil almost without the influence of the reflected laser pulse and the foil. Conseq…
We show that a commonly accepted transparency threshold for a thin foil in a strong circularly polarized normally incident laser pulse needs a refinement. We present a new analytical model, which correctly accounts for laser absorption. The refined threshold is determined not solely by the laser amplitude, but other parameters are equally or even more important. Our predictions are in a perfect agreement with PIC simulations. The refined criterion is crucial for configuring laser plasma experiments in the high field domain. Besides, an opaque foil steepens the pulse front, this can be importan…
The electron-positron pair production accompanying interaction of a circularly polarized laser pulse with a foil is studied for laser intensities higher than $10^{24}$W cm$^{-2}$. The laser energy penetrates into the foil due to the effect of the relativistic hole-boring. It is demonstrated that the electron-positron plasma is produced as a result of quantum-electrodynamical cascading in the field of the incident and reflected laser light in front of the foil. The incident and reflected laser light makes up the circularly polarized standing wave in the reference frame of the hole-boring front …
We have studied the propagation of fast electrons through laser irradiated Ti foils by monitoring the emission of hard X-rays and K-α radiation from bare foils and foils backed by a thick epoxy layer. Key observations include strong refluxing of electrons and divergence of the electron beam in the foil with evidence of magnetic field collimation. Our diagnostics have allowed us to estimate the fast electron temperature and fraction of laser energy converted to fast electrons. We have observed clear differences between the fast electron temperatures observed with bare and epoxy backed targets w…
A scenario for the enhanced laser-driven ion acceleration from a thin solid target at high laser intensity is considered, where the target is enclosed in a reflecting cavity. The laser pulse reflected from the target is redirected towards the target by reflection at the inner cavity wall. This scenario is discussed in the context of sub-wavelength foil acceleration in the radiation pressure regime, when plasma dynamics is known to be reasonably well described by the light-sail model. A semi-analytic formula is presented that describes the effect of cavity reflections in one-dimensional geometr…
A strong electron current triggered by a femtosecond relativistically intense laser pulse in a foil coil-like target is shown to be able to generate a solenoidal-type extremely strong magnetic field. The magnetic field lifetime sufficiently exceeds the laser pulse duration and is defined mainly by the target properties. The process of the magnetic field generation was studied with 3D PIC simulations. It is demonstrated that the pulse and the target parameters allow controlling the field strength and duration. The scheme studied is of great importance for laser-based magnetization technologies.
A new regime is described for Radiation Pressure Acceleration of a thin foil by an intense laser beam of above 10^20 W/cm^2. Highly monoenergetic proton beams extending to GeV energies can be produced with very high efficiency using circularly polarized light. The proton beams have a very small divergence angle (less than 4 degrees). This new method allows the construction of ultra-compact proton and ion accelerators with ultra-short particle bursts.
Experiments on ion acceleration by irradiation of ultra-thin diamond-like carbon (DLC) foils, with thicknesses well below the skin depth, irradiated with laser pulses of ultra-high contrast and linear polarization, are presented. A maximum energy of 13MeV for protons and 71MeV for carbon ions is observed with a conversion efficiency of > 10%. Two-dimensional particle-in-cell (PIC) simulations reveal that the increase in ion energies can be attributed to a dominantly collective rather than thermal motion of the foil electrons, when the target becomes transparent for the incident laser pulse.
We present a regime where an ultra-intense laser pulse interacting with a foil target results in high $γ$-photon conversion efficiency, obtained via three-dimensional quantum-electrodynamics particle-in-cell simulations. A single-cycle laser pulse is used under the tight-focusing condition for obtaining the $\mathrmλ^3$ regime. The simulations employ a radially polarized laser as it results in higher $γ$-photon conversion efficiency compared to both azimuthal and linear polarizations. A significant fraction of the laser energy is transferred to positrons, while a part of the electromagnetic wa…
Scaling laws of ion acceleration in ultrathin foils driven by radiation pressure of intense laser pulses are investigated by theoretical analysis and two-dimensional particle-in-cell simulations. Considering the instabilities are inevitable during laser plasma interaction, the maximum energy of ions should have two contributions: the bulk acceleration driven by radiation pressure and the sheath acceleration in the moving foil reference induced by hot electrons. A theoretical model is proposed to quantitatively explain the results that the cutoff energy and energy spread are larger than the pre…
Laser-plasma proton acceleration was investigated in the Target Normal Sheath Acceleration (TNSA) regime using a novel gas-foil target. The target is designed for reaching higher laser intensity at the foil plane owing to relativistic self-focusing and self compression of the pulse in the gas layer. Numerical 3D particle-in-cell (PIC) simulations were used to study pulse propagation in the gas, showing a nearly seven-fold increase in peak intensity. In the experiment, maximum proton energies showed high dependence on the energy transmission of the laser through the gas and a lesser dependence …
Monoenergetic ion bunch generation and acceleration from double layer thin foil target irradiated by intense linearly polarized (LP) laser pulse is investigated using two-dimensional (2D) particle-in-cell (PIC) simulations. The low-Z ions in the front layer of the target are accelerated by the laser-driven hot electrons and penetrate through the high-Z ion layer to generate a quasi-monoenergetic ion bunch, and this bunch will continue to be accelerated by the quasi-stable electrostatic sheath field which is formed by the immobile high-Z ions and the hot electrons. This mechanism offers possibi…
Geometric scaling of laser-driven proton focusing from hemispherical foils
Princeton University（普林斯顿大学）；Princeton Plasma Physics Laboratory（普林斯顿等离子体物理实验室）；Focused Energy Inc.（Focused Energy 公司）；University of Maryland, College Park（马里兰大学帕克分校）；University of Texas, Austin（德克萨斯大学奥斯汀分校）；Focused Energy GmbH（Focused Energy 有限公司）
Magnetized high energy density physics offers new opportunities for observing magnetic field-related physics for the first time in the laser-plasma context. We focus on one such phenomenon, which is the ability of a laser-irradiated magnetized plasma to amplify a seed magnetic field. We performed a series of fully kinetic 3D simulations of magnetic field amplification by a picosecond-scale relativistic laser pulse of intensity $4.2\times 10^{18}$ W/cm$^2$ incident on a thin foil. We observe axial magnetic field amplification from an initial 0.1 kT seed to 1.5 kT over a volume of several cubic …
We report the experimental generation of highly energetic carbon ions up to 48 MeV per nucleon by shooting double-layer targets composed of well-controlled slightly underdense plasma (SUP) and ultrathin foils with ultra-intense femtosecond laser pulses. Particle-in-cell simulations reveal that carbon ions residing in the ultrathin foils undergo radiation pressure acceleration and long-time sheath field acceleration in sequence due to the existence of the SUP in front of the foils. Such an acceleration scheme is especially suited for heavy ion acceleration with femtosecond laser pulses. The bre…
A scheme to generate magnetized relativistic plasmas in laboratory is proposed. It is based on interaction of ultra-high-intensity sub-picosecond laser pulses with few-micron thick foils or films. By means of Particle-In-Cell simulations it is shown that energetic electrons produced by the laser and evacuated at the rear of the target trigger an expansion of the target and builds up a strong azimuthal magnetic field. It is shown that in the expanding plasma sheath a ratio of the magnetic pressure and the electron rest-mass energy density exceeds unity whereas a the plasma pressure is lower tha…
We studied the hard x-ray emission and the K-alpha x-ray conversion efficiency produced by 60 fs high contrast frequency doubled Ti: sapphire laser pulse focused on Cu foil target. Cu K-alpha photon emission obtained with second harmonic laser pulse is more intense than the case of fundamental laser pulse. The Cu K-alpha conversion efficiency shows strong dependence on laser nonlinearly skewed pulse shape and reaches the maximum value 4x10-4 with 100 fs negatively skewed pulse. It shows the electron spectrum shaping contribute to the increase of conversion efficiency. Particle-in-cell simulati…
Incoherent photon emission by ultrarelativistic electrons in the normal incidence of a laser pulse on a foil is investigated by means of three-dimensional numerical simulations in the range of intensities $2 \times 10^{21} \text{--} 2 \times 10^{25} \text{W} \, \text{cm}^{-2}$ and electron densities $2 \times 10^{22} \text{--} 1 \times 10^{24} \text{cm}^{-3}$. We focus on properties of the resulting synchrotron radiation, such as its overall energy, directivity of the radiation pattern and slope of the energy spectrum. Regimes of laser-foil interactions are studied in the framework of a simple…
We have employed the VULCAN laser facility to generate a laser plasma X-ray source for use in photoionisation experiments. A nanosecond laser pulse with an intensity of order ${10}^{15}$ W{cm}$^{-2}$ was used to irradiate thin Ag or Sn foil targets coated onto a parylene substrate, and the L-shell emission in the $3.3-4.4$ keV range was recorded for both the laser-irradiated and non-irradiated sides. Both the experimental and simulation results show higher laser to X-ray conversion yields for Ag compared with Sn, with our simulations indicating yields approximately a factor of two higher than …
In this letter we report on an experimental study of high harmonic radiation generated in nanometer-scale foil targets irradiated under normal incidence. The experiments constitute the first unambiguous observation of odd-numbered relativistic harmonics generated by the $\vec{v}\times\vec{B}$ component of the Lorentz force verifying a long predicted property of solid target harmonics. Simultaneously the observed harmonic spectra allow in-situ extraction of the target density in an experimental scenario which is of utmost interest for applications such as ion acceleration by the radiation press…
By means of particle-in-cell numerical simulations, we investigate the emission of high-energy photons in laser-plasma interactions under ultrahigh-intensity conditions relevant to multi-petawatt laser systems. We first examine the characteristics of synchrotron radiation from laser-driven plasmas of varying density and size. In particular, we show and explain the dependence of the angular distribution of the radiated photons on the transparency or opacity of the plasma. We then study the competition of the synchrotron and Bremsstrahlung emissions in copper foil targets irradiated by $10^{22}\…
We study numerically the mechanisms of proton acceleration in gas-foil targets driven by an ultraintense femtosecond laser pulse. The target consists of a near-critical-density hydrogen gas layer of a few tens of microns attached to a solid carbon foil with a contaminant thin proton layer at its back side. Two-dimensional particle-in-cell simulations show that, at optimal gas density, the maximum energy of the contaminant protons is increased by a factor of $\sim 4$ compared to a single foil target. This improvement originates from the near-complete laser absorption into relativistic electrons…
Dense positrons are shown to be effectively generated from laser-solid interactions in the strong-field quantum electrodynamics (QED) regime. Whether these positrons are polarized has not yet been reported, limiting their potential applications. Here, by QED particle-in-cell simulations including electron-positron spin and photon polarization effects, we investigate a typical laser-solid setup that an ultraintense linearly polarized laser irradiates a foil target with $μ$m-scale-length preplasma. We find that once the positron yield becomes appreciable with the laser intensity exceeding $10^{2…
We derive a theoretical model for the Rayleigh-Taylor (RT)-like instability for a thin foil accelerated by an intense laser, taking into account finite wavelength effects in the laser wave field. The latter leads to the diffraction of the electromagnetic wave off the periodic structures arising from the instability of the foil, which significantly modifies the growth rate of the RT-like instability when the perturbations on the foil have wavenumbers comparable to or larger than the laser wavenumber. In particular, the growth rate has a local maximum at a perturbation wavenumber approximately e…
We present a detailed study of the electric and magnetic fields, which are created on plasma vacuum interfaces as a result of highly intense laser-matter-interactions. For the field generation ultra-thin polymer foils were irradiated with high intensity femtosecond and picosecond laser pulses with ultra-high contrast. To determine the temporal evolution and the spatial distribution of these fields the proton streak deflectometry method has been developed further and applied in two different imaging configurations. It enabled us to gather complementary information about the investigated field s…
Three dimensional Particle-In-Cell simulations describing the interaction of a short intense laser pulse with thin foils are presented. It is observed that the laser generated electron current decays into magnetically isolated filaments. The filaments grow in scale and magnitude by reconnection. Two different laser wavelengths are considered. The spatial separation of the filaments varies for the two wavelengths. Many current filaments carry net electric currents exceeding the Alfven current considerably.
We present results of energetic laser-ion acceleration from a tailored, near solid density gas target. Colliding hydrodynamic shocks compress a pure hydrogen gas jet into a 70 μm thick target prior to the arrival of the ultra-intense laser pulse. A density scan reveals the transition from a regime characterized by a wide angle, low energy beam to one of a more focused beam with a high energy halo. In the latter case, three dimensional simulations show the formation of a Z-pinch driven by the axial current resulting from laser wakefield accelerated electrons. Ions at the rear of the target are …
We report on a self-organizing, quasi-stable regime of laser proton acceleration, producing 1 GeV nano-Coulomb proton bunches from laser foil interaction at an intensity of 7*10^21 W/cm2. The results are obtained from 2D PIC simulations, using circular polarized light normally incident on a planar, 500 nm thick hydrogen foil with Gaussian transverse profile. While foil plasma driven in the wings of the driving pulse is dispersed, a stable central clump with 1 - 2 lamda diameter is forming on the axis. The stabilisation is related to laser light having passed the transparent parts of the foil i…
Radiation reaction effects on ion acceleration in laser foil interaction are investigated via analytical modeling and multi-dimensional particle-in-cell simulations. We find the radiation effects are important in the area where some electrons move backwards due to static charge separation field at the laser intensity of 1022 W=cm2. Radiation reaction tends to impede these backwards motion. In the optical transparency region ion acceleration is enhanced when the radiation effects are considered.
Efficient laser ion acceleration requires high laser intensities, which can only be obtained by tightly focusing laser radiation. In the radiation pressure acceleration regime, where the tightly focused laser driver leads to the appearance of the fundamental limit for the maximum attainable ion energy, this limit corresponds to the laser pulse group velocity as well as to another limit connected with the transverse expansion of the accelerated foil and consequent onset of the foil transparency. These limits can be relaxed by using composite targets, consisting of a thin foil followed by a near…
Using particle-in-cell simulations, we demonstrate an improvement of the target normal sheath acceleration (TNSA) of protons in non-periodically nanostructured targets with micron-scale thickness. Compared to standard flat foils, an increase in the proton cutoff energy by up to a factor of two is observed in foils coated with nanocones or perforated with nanoholes. The latter nano-perforated foils yield the highest enhancement, which we show to be robust over a broad range of foil thicknesses and hole diameters. The improvement of TNSA performance results from more efficient hot-electron gener…
A theory for laser ion acceleration is presented to evaluate the maximum ion energy in the interaction of ultrahigh contrast (UHC) intense laser with a nanometer-scale foil. In this regime the energy of ions may be directly related to the laser intensity and subsequent electron dynamics. This leads to a simple analytical expression for the ion energy gain under the laser irradiation of thin targets. Significantly, higher energies for thin targets than for thicker targets are predicted. Theory is concretized to the details of recent experiments which may find its way to compare with these resul…
Using multi-dimensional particle-in-cell (PIC) simulations we study ion acceleration from a foil irradiated by a circularly polarized laser pulse at 1022W/cm^2 intensity. When the foil is shaped initially in the transverse direction to match the laser intensity profile, the center part of the target can be uniformly accelerated for a longer time compared to a usual flat target. Target deformation and undesirable plasma heating are effectively suppressed. The final energy spectrum of the accelerated ion beam is improved dramatically. Collimated GeV quasi-mono-energetic ion beams carrying as muc…
A laser-boosted relativistic solid-density paraboloidal foil is known to efficiently reflect and focus a counterpropagating laser pulse. Here we show that in the case of an ultrarelativistic counterpropagating pulse, a high-energy and ultrahigh intensity reflected pulse can be more effectively generated by a relatively slow and heavy foil than by a fast and light one. This counterintuitive result is explained with the larger reflectivity of a heavy foil, which compensates for its lower relativistic Doppler factor. Moreover, since the counterpropagating pulse is ultrarelativistic, the foil is a…
Ultrafast proton radiography of the magnetic fields generated by a laser-driven coil current
Princeton Plasma Physics Laboratory, Princeton University（普林斯顿等离子体物理实验室，普林斯顿大学）；Department of Astrophysical Sciences, Princeton University（普林斯顿大学天体科学系）；Nuclear Engineering and Radiological Sciences (NERS), University of Michigan（密歇根大学核工程与放射科学系）；Laboratory for Laser Energetics, University of Rochester（罗切斯特大学激光能量学实验室）；General Atomics（通用原子能公司）
The creation of well-thermalized, hot and dense plasmas is attractive for warm dense matter studies. We investigate collisionally induced energy absorption of an ultraintense and ultrashort laser pulse in a solid copper target using particle-in-cell simulations. We find that, upon irradiation by a $2\times10^{20}{\rm\,W\,cm^{-2}}$ intensity, $60{\rm\,fs}$ duration, circularly polarized laser pulse, the electrons in the collisional simulation rapidly reach a well-thermalized distribution with ${\sim}3.5{\rm\,keV}$ temperature, while in the collisionless simulation the absorption is several orde…
It is demonstrated by three-dimensional quantum electrodynamics --- particle-in-cell (QED-PIC) simulations that vacuum breakdown wave in the form of QED cascade front can propagate in an extremely intense plane electromagnetic wave. The result disproves the statement that the self-sustained cascading is not possible in a plane wave configuration. In the simulations the cascade initiates during laser-foil interaction in the light sail regime. As a result, a constantly growing electron-positron plasma cushion is formed between the foil and laser radiation. The cushion plasma efficiently absorbs …
The formation of relativistic electron mirror produced via ionization of thin solid target by ultraintense femtosecond laser pulse is considered with the help of computer simulations. It is shown that the reflection of weak counter-propagating wave from such a mirror can produce the coherent radiation in X-ray and gamma-ray bands. The spectrum of up-conversed radiation is investigated.
The interaction of ultra-intense lasers with solid foils can be used to accelerate ions to high energies well exceeding 60 MeV. The non-linear relativistic motion of electrons in the intense laser radiation leads to their acceleration and later to the acceleration of ions. Ions can be accelerated from the front surface, the foil interior region, and the foil rear surface (TNSA, most widely used), or the foil may be accelerated as a whole if sufficiently thin (RPA). Here, we focus on the most widely used mechanism for laser ion-acceleration of TNSA. Starting from perfectly flat foils we show by…
Using high-resolution, two-dimensional particle-in-cell simulations, we investigate numerically the mechanisms of terahertz (THz) emissions in submicron-thick carbon solid foils driven by ultraintense ($\sim 10^{20}\,\rm W\,cm^{-2}$), ultrashort ($30\,\rm fs$) laser pulses at normal incidence. The considered range of target thicknesses extends down to the relativistic transparency regime that is known to optimize ion acceleration by femtosecond laser pulses. By disentangling the fields emitted by longitudinal and transverse currents, our analysis reveals that, within the first picosecond after…
Detailed radiation hydrodynamic simulations are carried out to investigate x-ray emission process in four high-Z planar targets namely, tungsten (W), gold (Au), lead (Pb) and uranium (U) irradiated by 1 ns, 351 nm flat top laser pulses. A thorough zoning analysis is performed for all laser driven high-Z foils over a wide intensity range of $10^{12}-10^{15} W/cm^{2}$ with appropriately chosen photon energy range and recombination parameter. The resulting variation of conversion efficiency over the full intensity range exhibits an optimum for all materials which is explained by considering the c…
We report on experimental studies of divergence of proton beams from nanometer thick diamond-like carbon (DLC) foils irradiated by an intense laser with high contrast. Proton beams with extremely small divergence (half angle) of 2 degree are observed in addition with a remarkably well-collimated feature over the whole energy range, showing one order of magnitude reduction of the divergence angle in comparison to the results from micrometer thick targets. We demonstrate that this reduction arises from a steep longitudinal electron density gradient and an exponentially decaying transverse profil…
High-energy-density electron-positron pair plasma production and its dynamics in a thin foil illuminated by two counter-propagating laser pulses are investigated through multi-dimensional particle-in-cell simulations. We compare the production of electron-positron pairs and gamma-photons via quantum electrodynamics processes in the relativistic transparent and opaque regimes, and find that the target transparency can significantly enhance the electron-positron pair production due to the formation of stable standing wave (SW). An optimum foil density of 200 - 280 n_c (n_c is the laser critical …
Although the interaction of a flat-foil with currently available laser intensities is now considered a routine process, during the last decade emphasis is given to targets with complex geometries aiming on increasing the ion energy. This work presents a target geometry where two symmetric side-holes and a central-hole are drilled into the foil. A study of the various side-holes and central-hole length combinations is performed with 2-dimensional particle-in-cell simulations for polyethylene targets and a laser intensity of 5.2x10^21 W cm^-2. The holed-targets show a remarkable increase of the …
The radiation pressure acceleration regime of laser ion acceleration requires high intensity laser pulses to function efficiently. Moreover the foil should be opaque for incident radiation during the interaction to ensure maximum momentum transfer from the pulse to the foil, which requires proper matching of the target to the laser pulse. However, in the ultrarelativistic regime, this leads to large acceleration distances, over which the high laser intensity for a Gaussian laser pulse must be maintained. It is shown that proper tailoring of the laser pulse profile can significantly reduce the …
We numerically investigate the impact of Coulomb collisions on the ion dynamics in high-$Z$, solid density caesium hydride and copper targets, irradiated by high-intensity ($I\approx2{-}5\times10^{20}{\rm\,Wcm^{-2}}$), ultrashort (${\sim}10{\rm\,fs}$), circularly polarized laser pulses, using particle-in-cell simulations. Collisions significantly enhance electron heating, thereby strongly increasing the speed of a shock wave launched in the laser-plasma interaction. In the caesium hydride target, collisions between the two ion species heat the protons to ${\sim}100{-}1000{\rm\,eV}$ temperature…
The acceleration of ions in the interaction of circular polarized laser pulses with overdense plasmas is investigated. For circular polarization laser pulses, the quasi-equilibrium for electrons is established due to the light pressure and the electrostatic field built up at the interacting front of the laser pulse. The ions located within the skin-depth of the laser pulse can be synchronously accelerated and bunched in the charge couple processes by the electrostatic field, and thereby monoenergetic and high intensity proton beam can be generated. The dynamics equations for accelerated ions a…
With the aid of large-scale three-dimensional QED-PIC simulations, we describe a realistic experimental configuration to measure collective effects that couple strong field quantum electrodynamics to plasma kinetics. For two counter propagating lasers interacting with a foil at intensities exceeding $10^{22}$ Wcm$^{-2}$, a binary result occurs; when quantum effects are included, a foil that classically would effectively transmit the laser pulse becomes opaque. This is a dramatic change in plasma behavior, directly as a consequence of the coupling of radiation reaction and pair production to pl…
Backward terahertz radiation can be produced by a high-intensity laser normally incident upon an underdense plasma. It is found that terahertz radiation is generated by electrons refluxing along the bubble shell. These shell electrons have similar dynamic trajectories and emit backward radiations to vacuum. This scheme has been proved through electron dynamic calculations as well as by using an ionic sphere model. In addition, the bubble shape is found to influence the radiation frequency, and this scheme can be implemented in both uniform and up-ramp density gradient plasma targets. The terah…
A two-phase model, where the plasma expansion is an isothermal one when laser irradiates and a following adiabatic one after laser ends, has been proposed to predict the maximum energy of the proton beams induced in the ultra-intense laser-foil interactions. The hot-electron recirculation in the ultra-intense laser-solid interactions has been accounted in and described by the time-dependent hot-electron density continuously in this model. The dilution effect of electron density as electrons recirculate and spread laterally has been considered. With our model, the scaling laws of maximum ion en…
The production of energetic (multi-GeV) heavy ion beams by acceleration of ultra-thin foils through the application of radiation pressure to a self-generated, imperfect plasma mirror (photon absorption probability η finite) is studied. To evaluate the foil dynamics a relativistic model was developed for a constant and relativistic invariant value of the phenomenological parameter η. The achievable efficiency of kinetic energy transfer to the matter has been evaluated as function of the parameters involved (η, the aimed average foil velocity in unit of the light speed β, etc.). The expected col…
