scholarly journals Improvement of proton beam quality by an optimized dragging field generated by the ultraintense laser interactions with a complex double-layer target

2016 ◽  
Vol 34 (3) ◽  
pp. 562-566 ◽  
Author(s):  
F. J. Wu ◽  
L. Q. Shan ◽  
W. M. Zhou ◽  
T. Duan ◽  
Y. L. Ji ◽  
...  
Keyword(s):  
Proton Beam ◽  
Double Layer ◽  
Beam Quality ◽  
Average Energy ◽  
Thin Foil ◽  
Pure Hydrogen ◽  
Carbon Ions ◽  
One Dimensional ◽  
Particle In Cell ◽  
Underdense Plasma

AbstractA scheme for the improvement of proton beam quality by the optimized dragging field from the interaction of ultraintense laser pulse with a complex double-layer target is proposed and demonstrated by one-dimensional particle-in-cell (Opic1D) simulations. The complex double-layer target consists of an overdense proton thin foil followed by a mixed hydrocarbon (CH) underdense plasma. Because of the existence of carbon ions, the dragging field in the mixed CH underdense plasma becomes stronger and flatter in the location of the proton beam than that in a pure hydrogen (H) underdense plasma. The optimized dragging field can keep trapping and accelerating protons in the mixed CH underdense target to high quality. Consequently, the energy spread of the proton beam in the mixed CH underdense plasma can be greatly reduced down to 2.6% and average energy of protons can reach to 9 GeV with circularly polarized lasers at intensities 2.74 × 1022 W/cm2.

scholarly journals Monoenergetic proton beam accelerated by single reflection mechanism only during hole-boring stage

2019 ◽  
Vol 7 ◽  
Author(s):  
Wenpeng Wang ◽  
Cheng Jiang ◽  
Shasha Li ◽  
Hao Dong ◽  
Baifei Shen ◽  
...  
Keyword(s):  
Proton Beam ◽  
Radiation Pressure ◽  
Proton Therapy ◽  
Beam Quality ◽  
Acceleration Process ◽  
Carbon Ions ◽  
Triple Layer ◽  
Rear Part ◽  
Beam Instabilities ◽  
Sharp Front

Multidimensional instabilities always develop with time during the process of radiation pressure acceleration, and are detrimental to the generation of monoenergetic proton beams. In this paper, a sharp-front laser is proposed to irradiate a triple-layer target (the proton layer is set between two carbon ion layers) and studied in theory and simulations. It is found that the thin proton layer can be accelerated once to hundreds of MeV with monoenergetic spectra only during the hole-boring (HB) stage. The carbon ions move behind the proton layer in the light-sail (LS) stage, which can shield any further interaction between the rear part of the laser and the proton layer. In this way, proton beam instabilities can be reduced to a certain extent during the entire acceleration process. It is hoped such a mechanism can provide a feasible way to improve the beam quality for proton therapy and other applications.

scholarly journals Effect of inside diameter of tip on proton beam produced by intense laser pulse on double-layer cone targets

2013 ◽  
Vol 31 (1) ◽  
pp. 123-127 ◽  
Author(s):  
Fengjuan Wu ◽  
Weimin Zhou ◽  
Lianqiang Shan ◽  
Zongqing Zhao ◽  
Jinqing Yu ◽  
...  
Keyword(s):  
Proton Beam ◽  
Double Layer ◽  
Intense Laser ◽  
Proton Beams ◽  
Particle In Cell ◽  
Inside Diameter ◽  
Peak Energy ◽  
Electro Magnetic ◽  
Cone Target ◽  
Beam Characteristics

AbstractThe laser-driven acceleration of proton beams from a double-layer cone target, comprised of a cone shaped high-Z material target with a low density proton layer, is investigated via two-dimensional fully relativistic electro-magnetic particle-in-cell simulations. The dependence of the inside diameter (ID) of the tip size of a double-layer cone target on proton beam characteristics is demonstrated. Our results show that the peak energy of proton beams significantly increases and the divergence angle decreases with decreasing ID size. This can be explained by the combined effects of a stronger laser field that is focused inside the cone target and a larger laser interaction area by reducing the ID size.

One-dimensional particle-in-cell simulation of a current-free double layer in an expanding plasma

2005 ◽  
Vol 12 (5) ◽  
pp. 052317 ◽  
Author(s):  
Albert Meige ◽  
Rod W. Boswell ◽  
Christine Charles ◽  
Miles M. Turner
Keyword(s):  
Double Layer ◽  
One Dimensional ◽  
Particle In Cell ◽  
Cell Simulation ◽  
A Current

scholarly journals Efficient ion acceleration by collective laser-driven electron dynamics with ultra-thin foil targets

2010 ◽  
Vol 28 (1) ◽  
pp. 215-221 ◽  
Author(s):  
S. Steinke ◽  
A. Henig ◽  
M. Schnürer ◽  
T. Sokollik ◽  
P.V. Nickles ◽  
...  
Keyword(s):  
Thin Foil ◽  
Laser Pulses ◽  
Maximum Energy ◽  
Skin Depth ◽  
Ion Acceleration ◽  
Carbon Ions ◽  
Incident Laser ◽  
Particle In Cell ◽  
Incident Laser Pulse ◽  
Ion Energies

AbstractExperiments 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 13 MeV for protons and 71 MeV 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.

scholarly journals Proton beam quality enhancement by spectral phase control of a PW-class laser system

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
T. Ziegler ◽  
D. Albach ◽  
C. Bernert ◽  
S. Bock ◽  
F.-E. Brack ◽  
...  
Keyword(s):  
Proton Beam ◽  
Laser Energy ◽  
Beam Quality ◽  
Laser System ◽  
Thin Foil ◽  
High Repetition Rate ◽  
Spectral Phase ◽  
Experimental Investigations ◽  
Enhancement Effect ◽  
Proton Acceleration

AbstractWe report on experimental investigations of proton acceleration from solid foils irradiated with PW-class laser-pulses, where highest proton cut-off energies were achieved for temporal pulse parameters that varied significantly from those of an ideally Fourier transform limited (FTL) pulse. Controlled spectral phase modulation of the driver laser by means of an acousto-optic programmable dispersive filter enabled us to manipulate the temporal shape of the last picoseconds around the main pulse and to study the effect on proton acceleration from thin foil targets. The results show that applying positive third order dispersion values to short pulses is favourable for proton acceleration and can lead to maximum energies of 70 MeV in target normal direction at 18 J laser energy for thin plastic foils, significantly enhancing the maximum energy compared to ideally compressed FTL pulses. The paper further proves the robustness and applicability of this enhancement effect for the use of different target materials and thicknesses as well as laser energy and temporal intensity contrast settings. We demonstrate that application relevant proton beam quality was reliably achieved over many months of operation with appropriate control of spectral phase and temporal contrast conditions using a state-of-the-art high-repetition rate PW laser system.

scholarly journals Geometric particle-in-cell methods for the Vlasov–Maxwell equations with spin effects

2021 ◽  
Vol 87 (3) ◽  
Author(s):  
Nicolas Crouseilles ◽  
Paul-Antoine Hervieux ◽  
Yingzhe Li ◽  
Giovanni Manfredi ◽  
Yajuan Sun
Keyword(s):  
Phase Space ◽  
Maxwell Equations ◽  
Stimulated Raman Scattering ◽  
Extended Phase ◽  
Five Dimensions ◽  
Particle In Cell ◽  
Spin Effects ◽  
Dimensional Phase Space ◽  
Spin Polarized ◽  
Underdense Plasma

We propose a numerical scheme to solve the semiclassical Vlasov–Maxwell equations for electrons with spin. The electron gas is described by a distribution function $f(t,{\boldsymbol x},{{{\boldsymbol p}}}, {\boldsymbol s})$ that evolves in an extended 9-dimensional phase space $({\boldsymbol x},{{{\boldsymbol p}}}, {\boldsymbol s})$ , where $\boldsymbol s$ represents the spin vector. Using suitable approximations and symmetries, the extended phase space can be reduced to five dimensions: $(x,{{p_x}}, {\boldsymbol s})$ . It can be shown that the spin Vlasov–Maxwell equations enjoy a Hamiltonian structure that motivates the use of the recently developed geometric particle-in-cell (PIC) methods. Here, the geometric PIC approach is generalized to the case of electrons with spin. Total energy conservation is very well satisfied, with a relative error below $0.05\,\%$ . As a relevant example, we study the stimulated Raman scattering of an electromagnetic wave interacting with an underdense plasma, where the electrons are partially or fully spin polarized. It is shown that the Raman instability is very effective in destroying the electron polarization.

Formation of an inverted sheath in a one-dimensional bounded plasma system studied by particle-in-cell simulation

2021 ◽  
Vol 28 (12) ◽  
pp. 123507
Author(s):  
T. Gyergyek ◽  
S. Costea ◽  
K. Bajt ◽  
A. Valič ◽  
J. Kovačič
Keyword(s):  
Plasma System ◽  
One Dimensional ◽  
Particle In Cell ◽  
Bounded Plasma ◽  
Cell Simulation

scholarly journals Brief Communication: The double layer in the separatrix region during magnetic reconnection

2015 ◽  
Vol 22 (2) ◽  
pp. 167-171
Author(s):  
J. Guo ◽  
B. Yu
Keyword(s):  
Electron Beam ◽  
Magnetic Reconnection ◽  
Double Layer ◽  
Particle In Cell ◽  
Acoustic Instability ◽  
Ion Acoustic ◽  
Evolution Stage ◽  
Spatial Size ◽  
Electron Holes ◽  
Observation Results

Abstract. With two-dimensional (2-D) particle-in-cell (PIC) simulations we investigate the evolution of the double layer (DL) driven by magnetic reconnection. Our results show that an electron beam can be generated in the separatrix region as magnetic reconnection proceeds. This electron beam could trigger the ion-acoustic instability; as a result, a DL accompanied with electron holes (EHs) can be found during the nonlinear evolution stage of this instability. The spatial size of the DL is about 10 Debye lengths. This DL propagates along the magnetic field at a velocity of about the ion-acoustic speed, which is consistent with the observation results.

scholarly journals Microcavity One-Dimensional Magnetophotonic Crystals with Double Layer Iron Garnet

2012 ◽  
Vol 36 (1_2) ◽  
pp. 42-45 ◽  
Author(s):  
V.N. Berzhansky ◽  
T.V. Mikhailova ◽  
A.V. Karavainikov ◽  
A.R. Prokopov ◽  
A.N. Shaposhnikov ◽  
...  
Keyword(s):  
Double Layer ◽  
One Dimensional ◽  
Magnetophotonic Crystals ◽  
Iron Garnet ◽  
Layer Iron
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