scholarly journals High-intensity laser-driven proton acceleration: influence of pulse contrast

Author(s):  
Paul McKenna ◽  
Filip Lindau ◽  
Olle Lundh ◽  
David Neely ◽  
Anders Persson ◽  
...  

Proton acceleration from the interaction of ultra-short laser pulses with thin foil targets at intensities greater than 10 18  W cm −2 is discussed. An overview of the physical processes giving rise to the generation of protons with multi-MeV energies, in well defined beams with excellent spatial quality, is presented. Specifically, the discussion centres on the influence of laser pulse contrast on the spatial and energy distributions of accelerated proton beams. Results from an ongoing experimental investigation of proton acceleration using the 10 Hz multi-terawatt Ti : sapphire laser (35 fs, 35 TW) at the Lund Laser Centre are discussed. It is demonstrated that a window of amplified spontaneous emission (ASE) conditions exist, for which the direction of proton emission is sensitive to the ASE-pedestal preceding the peak of the laser pulse, and that by significantly improving the temporal contrast, using plasma mirrors, efficient proton acceleration is observed from target foils with thickness less than 50 nm.

2007 ◽  
Vol 25 (3) ◽  
pp. 379-390 ◽  
Author(s):  
S. Varró

It has been shown that in the scattered radiation, generated by an ultrashort laser pulse impinging on a metal nano-layer, non-oscillatory wakefields appears with a definite sign. The magnitude of these wakefields is proportional to the incoming field strength, and the definite sign of them is governed by the cosine of the carrier-envelope phase difference of the incoming pulse. When we let such a Wakefield excite the electrons of a secondary target (say an electron beam, a metal surface or a gas jet), we can obtain 100 percent modulation in the electron signal in a given direction. This scheme can serve as a basis for the construction of a robust linear carrier-envelope phase difference meter. At relativistic laser intensities, the target is considered as a plasma layer in vacuum produced from a thin foil by a prepulse, which is followed by the main high-intensity laser pulse. The nonlinearities stemming from the relativistic kinematics lead to the appearance of higher-order harmonics in the scattered spectra. In general, the harmonic peaks are downshifted due to the presence of an intensity-dependent factor. This phenomenon is analogous to the famous intensity-dependent frequency shift in the nonlinear Thomson scattering on a single electron. In our analysis, an attention has also been paid to the role of the carrier-envelope phase difference of the incoming few-cycle laser pulse. It is also shown that the spectrum has a long tail where the heights of the peaks vary practically within one order of magnitude forming a quasi-continuum. Fourier synthesizing the components from this plateau region attosecond pulses has obtained.


2008 ◽  
Vol 36 (4) ◽  
pp. 1808-1811 ◽  
Author(s):  
Anna Levy ◽  
Tiberio Ceccotti ◽  
Horia Popescu ◽  
Fabrice Reau ◽  
Pascal D'Oliveira ◽  
...  

2021 ◽  
Author(s):  
Devki Nandan Gupta ◽  
Samuel Robert Yoffe ◽  
Arohi Jain ◽  
Bernhard Ersfeld ◽  
Dino Anthony Jaroszynski

Abstract Achieving high quality electron beams in laser wakefield accelerators requires stable guiding of the intense driving laser pulse, which is challenging because of mode mismatching due to relativistic self-focusing. Here we show how an intense pre-pulse can be used to prepare the phase-space distribution of plasma electrons encountered by a trailing laser pulse so that it produces its own well-matched guiding channel, while minimising wakefield evolution. Controlling the propagation of high intensity laser pulses is an essential step in developing useful wakefield accelerators and compact radiation sources.


2012 ◽  
Author(s):  
T. Tanimoto ◽  
M. Nishiuchi ◽  
Y. Mishima ◽  
K. Kikuyama ◽  
T. Morioka ◽  
...  

2013 ◽  
Vol 31 (4) ◽  
pp. 597-605 ◽  
Author(s):  
Jinqing Yu ◽  
Xiaolin Jin ◽  
Weimin Zhou ◽  
Bo Zhang ◽  
Zongqing Zhao ◽  
...  

AbstractWe investigate the influence of the initial size of the proton layer on proton acceleration in the interaction of high intensity laser pulses with double-layer targets by using two-dimensional particle-in-cell code. We discuss the influence of proton layer initial sizes on the cut-off energy, energy spread, and divergence angle of proton beam. It is found that Coulomb explosion plays an important role on the proton cut-off energy. This causes the cut-off energy to increase for increasing proton layer thickness, at the expense of energy spread. The proton divergence angle reaches a peak value and then falls again with increasing the width. Proton divergence angle grows with target thickness. It is found that there is an optimal thickness to obtain the narrowest energy spread, which may provide an effective method (change the size of proton layer) to obtain high quality proton beams. This work may serve to improve the understanding of sheath field proton acceleration.


2021 ◽  
Author(s):  
Devki N. Gupta ◽  
Samuel R. Yoffe ◽  
Arohi Jain ◽  
Bernhard Ersfeld ◽  
Dino A. Jaroszynski

Abstract Achieving high quality electron beams in laser wakefield accelerators requires stable guiding of the intense driving laser pulse, which is challenging because of mode mismatching due to relativistic self-focusing. Here we show how an intense pre-pulse can be used to prepare the phase-space distribution of plasma electrons encountered by a trailing laser pulse so that it produces its own well-matched guiding channel, while minimising wakefield evolution. Controlling the propagation of high intensity laser pulses is an essential step in developing useful wakefield accelerators and compact radiation sources.


2003 ◽  
Vol 90 (6) ◽  
Author(s):  
M. Zepf ◽  
E. L. Clark ◽  
F. N. Beg ◽  
R. J. Clarke ◽  
A. E. Dangor ◽  
...  

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 528
Author(s):  
Marcel Ruijter ◽  
Vittoria Petrillo ◽  
Thomas C. Teter ◽  
Maksim Valialshchikov ◽  
Sergey Rykovanov

High-energy radiation can be generated by colliding a relativistic electron bunch with a high-intensity laser pulse—a process known as Thomson scattering. In the nonlinear regime the emitted radiation contains harmonics. For a laser pulse whose length is comparable to its wavelength, the carrier envelope phase changes the behavior of the motion of the electron and therefore the radiation spectrum. Here we show theoretically and numerically the dependency of the spectrum on the intensity of the laser and the carrier envelope phase. Additionally, we also discuss what experimental parameters are required to measure the effects for a beamed pulse.


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