Laser-accelerated high-flux-intensity heavy-ion beams are important for new types of accelerators.A particle-in-cell program(Smilei) is employed to simulate the entire process of Station of Extreme Light(SEL) 100 PW l...Laser-accelerated high-flux-intensity heavy-ion beams are important for new types of accelerators.A particle-in-cell program(Smilei) is employed to simulate the entire process of Station of Extreme Light(SEL) 100 PW laser-accelerated heavy particles using different nanoscale short targets with a thickness of 100 nm Cr, Fe, Ag, Ta, Au, Pb, Th and U, as well as 200 nm thick Al and Ca. An obvious stratification is observed in the simulation. The layering phenomenon is a hybrid acceleration mechanism reflecting target normal sheath acceleration and radiation pressure acceleration, and this phenomenon is understood from the simulated energy spectrum,ionization and spatial electric field distribution. According to the stratification, it is suggested that high-quality heavy-ion beams could be expected for fusion reactions to synthesize superheavy nuclei. Two plasma clusters in the stratification are observed simultaneously, which suggest new techniques for plasma experiments as well as thinner metal targets in the precision machining process.展开更多
We demonstrate a novel picosecond optical parametric preamplification to generate high-stability, high-energy and high-contrast seed pulses. The 5ps seed pulse is amplified from 60pJ to 300μJ with an 8.6ps/ 3mJ pump ...We demonstrate a novel picosecond optical parametric preamplification to generate high-stability, high-energy and high-contrast seed pulses. The 5ps seed pulse is amplified from 60pJ to 300μJ with an 8.6ps/ 3mJ pump laser in a signal stage of short pulse non-collinear optical parametric chirped pulse amplification. The total gain is more than 106 and the rms energy stability is under 1.35%. The contrast ratio is higher than 10s within a scale of 20ps before the main pulse. Consequently, the improvement factor of the signal contrast is approximately equal to the gain 106 outside the pump window.展开更多
Laser wakefield accelerators （LWFAs） are considered to be one of the most compeuuve next- generation accelerator candidates. In this paper, we will study the potential high-flux electron beam production of an LWFA d...Laser wakefield accelerators （LWFAs） are considered to be one of the most compeuuve next- generation accelerator candidates. In this paper, we will study the potential high-flux electron beam production of an LWFA driven by petawatt-level laser pulses. In our three-dimensional particle-in-cell simulations, an optimal set of parameters gives -40 nC of charge with 2 PW laser power, thus -400 kA of instantaneous current if we assume the electron beam duration is 100 fs. This high flux and its secondary radiation are widely applicable in nuclear and QED physics, industrial imaging, medical and biological studies.展开更多
As optical parametric chirped pulse amplification has been widely adopted for the generation of extreme intensity laser sources,nonlinear crystals of large aperture are demanded for high-energy amplifiers.Yttrium calc...As optical parametric chirped pulse amplification has been widely adopted for the generation of extreme intensity laser sources,nonlinear crystals of large aperture are demanded for high-energy amplifiers.Yttrium calcium oxyborate(YCa_(4)O(BO_(3))_(3),YCOB)is capable of being grown with apertures exceeding 100 mm,which makes it possible for application in systems of petawatt scale.In this paper,we experimentally demonstrated for the first time to our knowledge,an ultra-broadband non-collinear optical parametric amplifier with YCOB for petawatt-scale compressed pulse generation at 800 nm.Based on the SG-II 5 PW facility,amplified signal energy of approximately 40 J was achieved and pump-to-signal conversion efficiency was up to 42.3%.A gain bandwidth of 87 nm was realized and supported a compressed pulse duration of 22.3 fs.The near-field and wavefront aberration represented excellent characteristics,which were comparable with those achieved in lithium triborate-based amplifiers.These results verified the great potential for YCOB utilization in the future.展开更多
In the 2015 review paper‘Petawatt Class Lasers Worldwide’a comprehensive overview of the current status of highpower facilities of>200 TW was presented.This was largely based on facility specifications,with some ...In the 2015 review paper‘Petawatt Class Lasers Worldwide’a comprehensive overview of the current status of highpower facilities of>200 TW was presented.This was largely based on facility specifications,with some description of their uses,for instance in fundamental ultra-high-intensity interactions,secondary source generation,and inertial confinement fusion(ICF).With the 2018 Nobel Prize in Physics being awarded to Professors Donna Strickland and Gerard Mourou for the development of the technique of chirped pulse amplification(CPA),which made these lasers possible,we celebrate by providing a comprehensive update of the current status of ultra-high-power lasers and demonstrate how the technology has developed.We are now in the era of multi-petawatt facilities coming online,with 100 PW lasers being proposed and even under construction.In addition to this there is a pull towards development of industrial and multi-disciplinary applications,which demands much higher repetition rates,delivering high-average powers with higher efficiencies and the use of alternative wavelengths:mid-IR facilities.So apart from a comprehensive update of the current global status,we want to look at what technologies are to be deployed to get to these new regimes,and some of the critical issues facing their development.展开更多
The use of ultra-high intensity laser beams to achieve extreme material states in the laboratory has become almost routine with the development of the petawatt laser. Petawatt class lasers have been constructed for sp...The use of ultra-high intensity laser beams to achieve extreme material states in the laboratory has become almost routine with the development of the petawatt laser. Petawatt class lasers have been constructed for specific research activities,including particle acceleration, inertial confinement fusion and radiation therapy, and for secondary source generation(x-rays, electrons, protons, neutrons and ions). They are also now routinely coupled, and synchronized, to other large scale facilities including megajoule scale lasers, ion and electron accelerators, x-ray sources and z-pinches. The authors of this paper have tried to compile a comprehensive overview of the current status of petawatt class lasers worldwide.The definition of ‘petawatt class' in this context is a laser that delivers >200 TW.展开更多
We present the design and experiment of a broadband optical parametric chirped-pulse amplifier(OPCPA) which provides high conversion efficiency and good beam quality at 808 nm wavelength. Using a three-dimensional spa...We present the design and experiment of a broadband optical parametric chirped-pulse amplifier(OPCPA) which provides high conversion efficiency and good beam quality at 808 nm wavelength. Using a three-dimensional spatial and temporal numerical model, several design considerations necessary to achieve high conversion efficiency, good beam quality and good output stability are discussed. To improve the conversion efficiency and broaden the amplified signal bandwidth simultaneously, the nonlinear crystal length and OPCPA parameters are analyzed and optimized with the concept of dissipating amplified idler between optical parametric amplification(OPA) of two crystals configuration.In the experiment, an amplifier consisting of two OPCPA stages of ‘L’ type configuration was demonstrated by using the optimized parameters. An amplified signal energy of 160 mJ was achieved with a total pump-to-signal efficiency of 35%(43% efficiency for the OPCPA stage 2). The output bandwidth of signal pulse reached 80 nm and the signal pulse was compressed to 24 fs. The energy stability reached 1.67% RMS at 3% pump energy variation. The optimized OPCPA amplifier operates at a repetition rate of 1 Hz and is used as a front-end injection for the main amplifier of SG-II 5PW laser facility.展开更多
There are several petawatt-scale laser facilities around the world and the fidelity of the pulses to target is critical in achieving the highest focused intensities and the highest possible contrast. The United Kingdo...There are several petawatt-scale laser facilities around the world and the fidelity of the pulses to target is critical in achieving the highest focused intensities and the highest possible contrast. The United Kingdom has three such laser facilities which are currently open for access to the academic community: Orion at AWE, Aldermaston and Vulcan & Astra-Gemini at the Central Laser Facility(CLF), STFC(Science and Technology Facilities Council)Rutherford Appleton Laboratory(RAL). These facilities represent the two main classes of petawatt facilities: the mixed OPCPA/Nd:glass high-energy systems of Orion and Vulcan and the ultra-short-pulse Ti:Sapphire system of AstraGemini. Many of the techniques used to enhance and control the pulse generation and delivery to target have been pioneered on these facilities. In this paper, we present the system designs which make this possible and discuss the contrast enhancement schemes that have been implemented.展开更多
Temporal contrast is one of the crucial physical determinants which guarantee the successful performance of laser–matter interaction experiments. We generally reviewed the influences on the temporal contrast in three...Temporal contrast is one of the crucial physical determinants which guarantee the successful performance of laser–matter interaction experiments. We generally reviewed the influences on the temporal contrast in three categories of noises based on the requirement by the physical mechanisms. The spatiotemporal influences on temporal contrast at the focal region of the chromatic aberration and propagation time difference introduced by large-aperture broadband spatial filters, which were spatiotemporally coupled with compression and focusing, were calculated and discussed with a practical case in SG-Ⅱ5 PW ultrashort petawatt laser. The system-wide spatiotemporal coupling existing in large-aperture broadband ultrashort petawatt lasers was proved to be one of the possible causes of temporal contrast degradation in the focal region.展开更多
A new generation of high power laser facilities will provide laser pulses with extremely high powers of 10 petawatt(PW)and even 100 PW, capable of reaching intensities of 1023 W/cm^2 in the laser focus. These ultra-hi...A new generation of high power laser facilities will provide laser pulses with extremely high powers of 10 petawatt(PW)and even 100 PW, capable of reaching intensities of 1023 W/cm^2 in the laser focus. These ultra-high intensities are nevertheless lower than the Schwinger intensity IS= 2.3×1029 W/cm^2 at which the theory of quantum electrodynamics(QED) predicts that a large part of the energy of the laser photons will be transformed to hard Gamma-ray photons and even to matter, via electron–positron pair production. To enable the investigation of this physics at the intensities achievable with the next generation of high power laser facilities, an approach involving the interaction of two colliding PW laser pulses is being adopted. Theoretical simulations predict strong QED effects with colliding laser pulses of 10 PW focused to intensities 10^(22) W/cm^2.展开更多
基金support from the Strategic Priority Research Program of the Chinese Academy of Sciences (No.XDB34030000)the National Key R & D Program of China (No.2022YFA1602404)+2 种基金National Natural Science Foundation of China (No. U1832129)the Youth Innovation Promotion Association of the Chinese Academy of Sciences (No.2017309)the Program for Innovative Research Team (in Science and Technology) in University of Henan Province of China (No.21IRTSTHN011)。
文摘Laser-accelerated high-flux-intensity heavy-ion beams are important for new types of accelerators.A particle-in-cell program(Smilei) is employed to simulate the entire process of Station of Extreme Light(SEL) 100 PW laser-accelerated heavy particles using different nanoscale short targets with a thickness of 100 nm Cr, Fe, Ag, Ta, Au, Pb, Th and U, as well as 200 nm thick Al and Ca. An obvious stratification is observed in the simulation. The layering phenomenon is a hybrid acceleration mechanism reflecting target normal sheath acceleration and radiation pressure acceleration, and this phenomenon is understood from the simulated energy spectrum,ionization and spatial electric field distribution. According to the stratification, it is suggested that high-quality heavy-ion beams could be expected for fusion reactions to synthesize superheavy nuclei. Two plasma clusters in the stratification are observed simultaneously, which suggest new techniques for plasma experiments as well as thinner metal targets in the precision machining process.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11604350 and 61405211
文摘We demonstrate a novel picosecond optical parametric preamplification to generate high-stability, high-energy and high-contrast seed pulses. The 5ps seed pulse is amplified from 60pJ to 300μJ with an 8.6ps/ 3mJ pump laser in a signal stage of short pulse non-collinear optical parametric chirped pulse amplification. The total gain is more than 106 and the rms energy stability is under 1.35%. The contrast ratio is higher than 10s within a scale of 20ps before the main pulse. Consequently, the improvement factor of the signal contrast is approximately equal to the gain 106 outside the pump window.
基金supported by Extreme Light Infrastructure- Nuclear Physics (ELI-NP) Phase Ⅱa project co-financed by the Romanian Government and European Union through the European Regional Development FundThe EPOCH code project was funded by the UK EPSRC grants EP/G054950/1, EP/ G056803/1, EP/G055165/1 and EP/ M022463/1
文摘Laser wakefield accelerators （LWFAs） are considered to be one of the most compeuuve next- generation accelerator candidates. In this paper, we will study the potential high-flux electron beam production of an LWFA driven by petawatt-level laser pulses. In our three-dimensional particle-in-cell simulations, an optimal set of parameters gives -40 nC of charge with 2 PW laser power, thus -400 kA of instantaneous current if we assume the electron beam duration is 100 fs. This high flux and its secondary radiation are widely applicable in nuclear and QED physics, industrial imaging, medical and biological studies.
基金partially supported by the Shanghai Natural Science Foundation(No.20ZR1464400)the National Natural Science Foundation of China(NSFC)(Nos.12074399,12204500 and 12004403)+4 种基金the Key Projects of Intergovernmental International Scientific and Technological Innovation Cooperation(No.2021YFE0116700)the Shanghai Sailing Program(No.22YF1455300)the International Partnership Program of the Chinese Academy of Sciences(No.181231KYSB20170022)the Chinese Academy of Sciences(Nos.CXJJ-21S015,XDA25020311 and XDA25020105)NSAF(No.U1930126)
文摘As optical parametric chirped pulse amplification has been widely adopted for the generation of extreme intensity laser sources,nonlinear crystals of large aperture are demanded for high-energy amplifiers.Yttrium calcium oxyborate(YCa_(4)O(BO_(3))_(3),YCOB)is capable of being grown with apertures exceeding 100 mm,which makes it possible for application in systems of petawatt scale.In this paper,we experimentally demonstrated for the first time to our knowledge,an ultra-broadband non-collinear optical parametric amplifier with YCOB for petawatt-scale compressed pulse generation at 800 nm.Based on the SG-II 5 PW facility,amplified signal energy of approximately 40 J was achieved and pump-to-signal conversion efficiency was up to 42.3%.A gain bandwidth of 87 nm was realized and supported a compressed pulse duration of 22.3 fs.The near-field and wavefront aberration represented excellent characteristics,which were comparable with those achieved in lithium triborate-based amplifiers.These results verified the great potential for YCOB utilization in the future.
文摘In the 2015 review paper‘Petawatt Class Lasers Worldwide’a comprehensive overview of the current status of highpower facilities of>200 TW was presented.This was largely based on facility specifications,with some description of their uses,for instance in fundamental ultra-high-intensity interactions,secondary source generation,and inertial confinement fusion(ICF).With the 2018 Nobel Prize in Physics being awarded to Professors Donna Strickland and Gerard Mourou for the development of the technique of chirped pulse amplification(CPA),which made these lasers possible,we celebrate by providing a comprehensive update of the current status of ultra-high-power lasers and demonstrate how the technology has developed.We are now in the era of multi-petawatt facilities coming online,with 100 PW lasers being proposed and even under construction.In addition to this there is a pull towards development of industrial and multi-disciplinary applications,which demands much higher repetition rates,delivering high-average powers with higher efficiencies and the use of alternative wavelengths:mid-IR facilities.So apart from a comprehensive update of the current global status,we want to look at what technologies are to be deployed to get to these new regimes,and some of the critical issues facing their development.
文摘The use of ultra-high intensity laser beams to achieve extreme material states in the laboratory has become almost routine with the development of the petawatt laser. Petawatt class lasers have been constructed for specific research activities,including particle acceleration, inertial confinement fusion and radiation therapy, and for secondary source generation(x-rays, electrons, protons, neutrons and ions). They are also now routinely coupled, and synchronized, to other large scale facilities including megajoule scale lasers, ion and electron accelerators, x-ray sources and z-pinches. The authors of this paper have tried to compile a comprehensive overview of the current status of petawatt class lasers worldwide.The definition of ‘petawatt class' in this context is a laser that delivers >200 TW.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.11304332,11704392,and 61705245)
文摘We present the design and experiment of a broadband optical parametric chirped-pulse amplifier(OPCPA) which provides high conversion efficiency and good beam quality at 808 nm wavelength. Using a three-dimensional spatial and temporal numerical model, several design considerations necessary to achieve high conversion efficiency, good beam quality and good output stability are discussed. To improve the conversion efficiency and broaden the amplified signal bandwidth simultaneously, the nonlinear crystal length and OPCPA parameters are analyzed and optimized with the concept of dissipating amplified idler between optical parametric amplification(OPA) of two crystals configuration.In the experiment, an amplifier consisting of two OPCPA stages of ‘L’ type configuration was demonstrated by using the optimized parameters. An amplified signal energy of 160 mJ was achieved with a total pump-to-signal efficiency of 35%(43% efficiency for the OPCPA stage 2). The output bandwidth of signal pulse reached 80 nm and the signal pulse was compressed to 24 fs. The energy stability reached 1.67% RMS at 3% pump energy variation. The optimized OPCPA amplifier operates at a repetition rate of 1 Hz and is used as a front-end injection for the main amplifier of SG-II 5PW laser facility.
文摘There are several petawatt-scale laser facilities around the world and the fidelity of the pulses to target is critical in achieving the highest focused intensities and the highest possible contrast. The United Kingdom has three such laser facilities which are currently open for access to the academic community: Orion at AWE, Aldermaston and Vulcan & Astra-Gemini at the Central Laser Facility(CLF), STFC(Science and Technology Facilities Council)Rutherford Appleton Laboratory(RAL). These facilities represent the two main classes of petawatt facilities: the mixed OPCPA/Nd:glass high-energy systems of Orion and Vulcan and the ultra-short-pulse Ti:Sapphire system of AstraGemini. Many of the techniques used to enhance and control the pulse generation and delivery to target have been pioneered on these facilities. In this paper, we present the system designs which make this possible and discuss the contrast enhancement schemes that have been implemented.
基金supported by the National Natural Science Foundation of China (NSFC) (No. 11304332)Key Projects of International Cooperation in Chinese Academy of Sciences
文摘Temporal contrast is one of the crucial physical determinants which guarantee the successful performance of laser–matter interaction experiments. We generally reviewed the influences on the temporal contrast in three categories of noises based on the requirement by the physical mechanisms. The spatiotemporal influences on temporal contrast at the focal region of the chromatic aberration and propagation time difference introduced by large-aperture broadband spatial filters, which were spatiotemporally coupled with compression and focusing, were calculated and discussed with a practical case in SG-Ⅱ5 PW ultrashort petawatt laser. The system-wide spatiotemporal coupling existing in large-aperture broadband ultrashort petawatt lasers was proved to be one of the possible causes of temporal contrast degradation in the focal region.
基金support from the National Key Research and Development Program of China(No.2016YFA0300803)support from the Project of Shanghai HIgh repetition rate XFEL aNd Extreme light facility(SHINE)+13 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB16)support from the EPSRC,UK(Nos.EP/L013975 and EP/N022696/1)support from Extreme Light Infrastructure Nuclear Physics(ELI-NP) Phase IIa project co-financed by the Romanian Government and the European Union through the European Regional Development Fundsupport from EPSRC(No.EP/M018091/1)support from EPSRC(No.EP/M018555/1)STFC(Nos.ST/J002062/1 and ST/P002021/1)Horizon2020 funding from the European Research Council(ERC)(No.682399)support from the National Natural Science Foundation of China(Nos.11622547,11875319,11875091,11474360,and 11175255)the National Key Research and Development Program of China(No.2018YFA0404802)the Science Challenge Program(No.TZ2016005)the Hunan Province Science and Technology Program of China(No.2017RS3042)supported by the National Natural Science Foundation of China(Nos.11347028,11405083,and 11675075)UK Engineering and Physics Sciences Research Council(Nos.EP/G054940/1,EP/G055165/1,and EP/G056803/1)
文摘A new generation of high power laser facilities will provide laser pulses with extremely high powers of 10 petawatt(PW)and even 100 PW, capable of reaching intensities of 1023 W/cm^2 in the laser focus. These ultra-high intensities are nevertheless lower than the Schwinger intensity IS= 2.3×1029 W/cm^2 at which the theory of quantum electrodynamics(QED) predicts that a large part of the energy of the laser photons will be transformed to hard Gamma-ray photons and even to matter, via electron–positron pair production. To enable the investigation of this physics at the intensities achievable with the next generation of high power laser facilities, an approach involving the interaction of two colliding PW laser pulses is being adopted. Theoretical simulations predict strong QED effects with colliding laser pulses of 10 PW focused to intensities 10^(22) W/cm^2.
