Recently there has been great progress in laser-driven plasma-based accelerators by exploiting high-power lasers,where electron beams can be accelerated to multi-GeV energy in a centimeter-scale plasma due to the lase...Recently there has been great progress in laser-driven plasma-based accelerators by exploiting high-power lasers,where electron beams can be accelerated to multi-GeV energy in a centimeter-scale plasma due to the laser wakefield acceleration mechanism. While, to date, worldwide research on laser plasma accelerators has been focused on the creation of compact particle and radiation sources for basic sciences, medical and industrial applications, there is great interest in applications for high-energy physics and astrophysics, exploring unprecedented high-energy frontier phenomena. In this context, we present an overview of experimental achievements in laser plasma acceleration from the perspective of the production of GeV-level electron beams, and deduce the scaling formulas capable of predicting experimental results self-consistently, taking into account the propagation of a relativistic laser pulse through plasma and the accelerating field reduction due to beam loading. Finally, we present design examples for 10-GeV-level laser plasma acceleration, which is expected in near-term experiments by means of petawatt-class lasers.展开更多
Recently, intense research into laser plasma accelerators has achieved great progress in the production of high-energy,high-quality electron beams with Ge V-level energies in a cm-scale plasma. These electron beams op...Recently, intense research into laser plasma accelerators has achieved great progress in the production of high-energy,high-quality electron beams with Ge V-level energies in a cm-scale plasma. These electron beams open the door for broad applications in fundamental, medical, and industrial sciences. Here we present conceptual designs of an extreme ultraviolet radiation source for next-generation lithography and a laser Compton Gamma-beam source for nuclear physics research on a table-top scale.展开更多
Multistage laser wakefield accelerators that are coupled with variable-curvature plasma channels make it possible to efficiently accelerate electrons to high energies that exceed dephasing and pump depletion limits.Se...Multistage laser wakefield accelerators that are coupled with variable-curvature plasma channels make it possible to efficiently accelerate electrons to high energies that exceed dephasing and pump depletion limits.Seamless coupling between laser and particle beams may envisage future energy-frontier colliders of revolutionarily small size and cost.展开更多
Terahertz(THz=10^(12) cycles per second,or T-ray)radiation sources are indispensable for modern materials science,chemical and biomedical imaging and sensing,as well as for a broad range of applications in diagnostic ...Terahertz(THz=10^(12) cycles per second,or T-ray)radiation sources are indispensable for modern materials science,chemical and biomedical imaging and sensing,as well as for a broad range of applications in diagnostic systems and advanced telecommunications1,2.The electromagnetic spectrum of the THz radiation is loosely characterized by the frequency range of 0.1−10 THz,or wavelengths between 30μm and 3 mm.In particular,a low photon energy of 4.2 meV or 48 K at 1 THz,which is less than the thermal energy at room temperature,allows precise measurements with a simplified setup and very high signal-to-noise ratio in time-domain pulsed THz spectroscopy2.Since the spectral region is located on the boundary between electronics and photonics,the diversity of the THz sources relies on either frequency up-conversion of electronic sources,such as solid-state photo-switches and radio-frequency(RF)electron-beam accelerators3,or frequency down-conversion of optical sources,such as optical rectification2,3 in nonlinear optical processes and laser-gas interaction induced by twocolor lasers3.Both technologies,however,exploit ultrashort pulse lasers as a driver.In a recent publication,Tian et al.4 at Shanghai Institute of Optics and Fine Mechanics(SIOM)and Nankai University developed a new THz radiation source using a laser-driven wire that generates a femtosecond electron bunch and helical undulator fields to emit THz synchrotron radiation with high efficiency.展开更多
In this letter, we discuss the increase in the average cluster size by lowering the stagnation temperature of the methane （CH4） gas. The Coulomb explosion experiments are conducted to estimate the cluster size and t...In this letter, we discuss the increase in the average cluster size by lowering the stagnation temperature of the methane （CH4） gas. The Coulomb explosion experiments are conducted to estimate the cluster size and the size distribution. The average CH4 cluster sizes Nay of 6 230 and 6 580 are acquired with the source conditions of 30 bars at 240 K and 60 bars at 296 K, respectively. Empirical estimation suggests a five-fold increase in the average size of the CH4 clusters at 240 K compared with that at room temperature under a backing pressure of 30 bars. A strong nonlinear Hagena parameter relation （Г^＊∝ T0^-3.3） for the CH4 clusters is revealed. The results may be favorable for the production of large-sized clusters by using gases at low temperature and high back pressures.展开更多
基金supported by Project Code IBS-R012-D1supported by the National Natural Science Foundation of China (Project No. 51175324)
文摘Recently there has been great progress in laser-driven plasma-based accelerators by exploiting high-power lasers,where electron beams can be accelerated to multi-GeV energy in a centimeter-scale plasma due to the laser wakefield acceleration mechanism. While, to date, worldwide research on laser plasma accelerators has been focused on the creation of compact particle and radiation sources for basic sciences, medical and industrial applications, there is great interest in applications for high-energy physics and astrophysics, exploring unprecedented high-energy frontier phenomena. In this context, we present an overview of experimental achievements in laser plasma acceleration from the perspective of the production of GeV-level electron beams, and deduce the scaling formulas capable of predicting experimental results self-consistently, taking into account the propagation of a relativistic laser pulse through plasma and the accelerating field reduction due to beam loading. Finally, we present design examples for 10-GeV-level laser plasma acceleration, which is expected in near-term experiments by means of petawatt-class lasers.
基金supported by the National Natural Science Foundation of China (Project No. 51175324)supported by IZEST, Ecole Polytechnique, France,Shanghai Jiao Tong University, Institute of Physics, CAS, Chinathe Center for Relativistic Laser Science, Institute for Basic Science (IBS), Korea
文摘Recently, intense research into laser plasma accelerators has achieved great progress in the production of high-energy,high-quality electron beams with Ge V-level energies in a cm-scale plasma. These electron beams open the door for broad applications in fundamental, medical, and industrial sciences. Here we present conceptual designs of an extreme ultraviolet radiation source for next-generation lithography and a laser Compton Gamma-beam source for nuclear physics research on a table-top scale.
文摘Multistage laser wakefield accelerators that are coupled with variable-curvature plasma channels make it possible to efficiently accelerate electrons to high energies that exceed dephasing and pump depletion limits.Seamless coupling between laser and particle beams may envisage future energy-frontier colliders of revolutionarily small size and cost.
文摘Terahertz(THz=10^(12) cycles per second,or T-ray)radiation sources are indispensable for modern materials science,chemical and biomedical imaging and sensing,as well as for a broad range of applications in diagnostic systems and advanced telecommunications1,2.The electromagnetic spectrum of the THz radiation is loosely characterized by the frequency range of 0.1−10 THz,or wavelengths between 30μm and 3 mm.In particular,a low photon energy of 4.2 meV or 48 K at 1 THz,which is less than the thermal energy at room temperature,allows precise measurements with a simplified setup and very high signal-to-noise ratio in time-domain pulsed THz spectroscopy2.Since the spectral region is located on the boundary between electronics and photonics,the diversity of the THz sources relies on either frequency up-conversion of electronic sources,such as solid-state photo-switches and radio-frequency(RF)electron-beam accelerators3,or frequency down-conversion of optical sources,such as optical rectification2,3 in nonlinear optical processes and laser-gas interaction induced by twocolor lasers3.Both technologies,however,exploit ultrashort pulse lasers as a driver.In a recent publication,Tian et al.4 at Shanghai Institute of Optics and Fine Mechanics(SIOM)and Nankai University developed a new THz radiation source using a laser-driven wire that generates a femtosecond electron bunch and helical undulator fields to emit THz synchrotron radiation with high efficiency.
基金We would like to thank Prof. Yuxin Leng, Engr. Yi Xu, and master＇s degree student Xiaoyang Guo for the operation and maintenance of the laser system. This work was supported by the Knowledge Innovation Program of the Chinese Academic of Sciences （No. KGCX2- YW-424）, the National Natural Science Foundation of China （Nos. 11104291, 51175324, and 11005080）, tile Shanghai Committee of Science and Technology, China （No. 11ZR1441300）, and the Cooperation in the Development and Application of Femtosecond Petta-watt Level Ultra-intense and Ultra-short Laser System （No. 2011DFAl1300）. K. Nakajima is supported by the Chinese Academy of Sciences Visiting Professorship for Senior International Scientists （No. 2010T2G02）.
文摘In this letter, we discuss the increase in the average cluster size by lowering the stagnation temperature of the methane （CH4） gas. The Coulomb explosion experiments are conducted to estimate the cluster size and the size distribution. The average CH4 cluster sizes Nay of 6 230 and 6 580 are acquired with the source conditions of 30 bars at 240 K and 60 bars at 296 K, respectively. Empirical estimation suggests a five-fold increase in the average size of the CH4 clusters at 240 K compared with that at room temperature under a backing pressure of 30 bars. A strong nonlinear Hagena parameter relation （Г^＊∝ T0^-3.3） for the CH4 clusters is revealed. The results may be favorable for the production of large-sized clusters by using gases at low temperature and high back pressures.
