High-efficiency water-window x-ray generation from nanowire array targets irradiated with femtosecond laser pulses

Shou, Yinren; Kong, Defeng; Wang, Pengjie; Mei, Zhusong; Cao, Zhengxuan; Pan, Zhuo; Li, Yunhui; Xu, Songyun; Qi, Guijun; Chen, Shiyou; Zhao, Jiarui; Zhao, Yanying; Fu, Changbo; Luo, Wen; Zhang, Guoqiang; Yan, Xueqing; Ma, Wu

doi:10.1364/oe.417512

Cited by 14 publications

(5 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…11 In addition, several applications of nanowire array targets have been proposed, such as proton acceleration, [15][16][17] neutron generation, [18][19][20] and bright x-ray sources. 21,22 So far, these results have been obtained in experiments using an ultrashort pulse laser with a pulse duration below subpicoseconds. When a laser with a longer pulse duration is irradiated into a nanowire array target, it is expected that the laser will be irradiated for a longer time than the plasma fills the space between the wires.…”

Section: Introductionmentioning

confidence: 86%

Ultrahigh-energy density state in nanowire arrays irradiated with picosecond kilojoule-class ultra-intense laser

Tanaka,

Maeda,

Hironaka

et al. 2023

AIP Advances

View full text Add to dashboard Cite

Ultrahigh-energy density (UHED) states greater than 1 Gbar pressure are typically observed under extreme conditions, such as in the core of an inertial confinement fusion implosion. A novel alternative approach for generating volumetric UHED states is to use nanowire arrays irradiated with a femtosecond ultrahigh-intensity laser. In this paper, we present an experimental investigation on laser absorption and energy transport in nanowire arrays irradiated with a picosecond kilojoule petawatt laser. The laser–target interactions were studied by measuring the x-ray emission and escaping hot electrons from a bare Cu foil and a foil with a nanowire array grown on its surface. The measured Cu-Kα and He-α emissions from the nanowire array were higher than those from the flat foil. In addition, hot electrons observed from the front surface of the nanowire array were enhanced. On the other hand, despite the stronger Kα emission from the nanowire array and the enhancement of hot electrons escaping from the front surface of the nanowire array, the number of hot electrons observed from the rear side of the flat foil target was slightly lower than that of the flat foil. A comparison of the experimental results with the results of a two-dimensional particle-in-cell simulation code suggested that the magnetic fields generated around the periodic nanowire array trap hot electrons, improving the electron-to-target energy coupling and efficiently producing UHED states.

show abstract

Section: Introductionmentioning

confidence: 86%

Ultrahigh-energy density state in nanowire arrays irradiated with picosecond kilojoule-class ultra-intense laser

Tanaka,

Maeda,

Hironaka

et al. 2023

AIP Advances

View full text Add to dashboard Cite

show abstract

“…The gap between them has led to continuous efforts in raising the proton energies based on realistic laser conditions, including improved target designs such as 'snow flake' [10], grating [11], nanotube foam [12], nanospheres [13], micro-wire arrays [14], nanochannels [15] and even bacteria [16], among which an important direction is using micro-structured targets. For example, micro-wire array (MWA) targets have been proposed to enhance laser energy conversion efficiency into not only energetic ions [17][18][19][20][21], but also electrons [22-24], x-ray emission [25,26], and positrons [27].…”

Section: Introductionmentioning

confidence: 99%

“…When an ultrahigh contrast femtosecond laser penetrates deep into the MWA, it creates a large volumetrically heated plasma [24][25][26], which is the major reason for the high-efficiency generation of x-rays and relativistic electrons. Further, the electrons within the wires are pulled out by the laser field and accelerated via direct laser acceleration (DLA) [28], leading to substantial enhancement in both the population and energies of the produced electron beam [23].…”

Section: Introductionmentioning

confidence: 99%

Enhanced laser-driven backward proton acceleration using micro-wire array targets

Fan

Wang

et al. 2023

Front. Phys.

Self Cite

View full text Add to dashboard Cite

Micro-structured targets can be employed to enhance the coupling of laser energy to the high energy density plasma. Here we report on experimental measurement of enhanced proton beam energy from laser-driven micro-wire array (MWA) targets along the backward direction. An ultra-intense (∼2×1020W/cm2) laser pulse of ∼ 40 fs pulse duration interacts with the MWA structure and induces large population of energetic electrons. The enhanced sheath field efficiently accelerates protons both transversely and longitudinally. The spectrometers record proton cut-off energy of around 16 MeV and temperature 813keV along the backward direction, which is 20%−60% higher than that of a flat target under commensurate laser conditions. Comparison with particle-in-cell simulations suggests that the enhancement originates from the increased temperature and population of the hot electrons within the micro-wires. These measurements provide a direct probe of the high energy density plasma condition in laser-driven solid targets and a useful benchmark for further studies on laser-driven micro-structured targets.

show abstract

“…Experimental data indicate that microstructure can greatly raise the temperature of hot electrons beyond that of the ponderomotive acceleration 29,30 . In the case of picosecond relativistic lasers irradiating microstructure targets at large angles, the yield of electron and x-ray could be increased 31,32 , but the proton energy from TNSA remains unchanged 27 or even becomes less 33 . The main reason is that the rising edge of picosecond lasers is long enough to ionize the surface structure so that the plasma in ll could shutter the laser from further interaction.…”

Section: Introductionmentioning

confidence: 99%

High Efficiency Laser-Driven Proton Sources Using 3D-Printed Micro-Structure

Qin

Zhang

et al. 2021

Preprint

View full text Add to dashboard Cite

We applied 3D-printed microwire-array (MWA) structure to boost the energy conversion efficiency of laser proton acceleration. The advanced nano-printing technique allows precise control on the spacing and geometrical size of 3D structures at 100-500 nm resolution. Under irradiation of high contrast laser pulse (15J, 35fs), the MWA target generates over 1.2×1012 protons (> 1MeV) with cut-off energies extending to 25MeV, corresponding to top-end of 8.7% energy conversion efficiency from femtosecond lasers. When comparing to flat foils the efficiency is enhanced by three times, while the cut-off energy is increased by 30-70% depending on their thicknesses. By precisely controlling the array period via 3D nano-printing, we found the dependence of proton energy/conversion-efficiency on the spacing of the MWA. The experimental trend is well reproduced by hydrodynamic and Particle-In-Cell simulations, which reveal for the first time the modulation of pre-plasma profile induced by laser diffraction within the fine structures. Optimal geometry for laser-proton acceleration is therefore strongly modified. Our work validates the use of 3D-printed micro-structures to produce high efficiency laser-driven particle sources and pointed out the new effect in optimizing the experimental conditions.

show abstract

High-efficiency water-window x-ray generation from nanowire array targets irradiated with femtosecond laser pulses

Cited by 14 publications

References 37 publications

Ultrahigh-energy density state in nanowire arrays irradiated with picosecond kilojoule-class ultra-intense laser

Ultrahigh-energy density state in nanowire arrays irradiated with picosecond kilojoule-class ultra-intense laser

Enhanced laser-driven backward proton acceleration using micro-wire array targets

High Efficiency Laser-Driven Proton Sources Using 3D-Printed Micro-Structure

Contact Info

Product

Resources

About