A multichannel calorimeter system is designed and constructed which is capable of delivering single-shot and broadband spectral measurement of terahertz(THz) radiation generated in intense laser–plasma interactions. ...A multichannel calorimeter system is designed and constructed which is capable of delivering single-shot and broadband spectral measurement of terahertz(THz) radiation generated in intense laser–plasma interactions. The generation mechanism of backward THz radiation(BTR) is studied by using the multichannel calorimeter system in an intense picosecond laser–solid interaction experiment. The dependence of the BTR energy and spectrum on laser energy, target thickness and pre-plasma scale length is obtained. These results indicate that coherent transition radiation is responsible for the low-frequency component(<1 THz) of BTR. It is also observed that a large-scale pre-plasma primarily enhances the high-frequency component(>3 THz) of BTR.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supported by the Newton China–UK joint research grant on laser–ion acceleration and novel terahertz radiationEPSRC grant EP/K022415/1 on advanced laser–ion acceleration strategies toward next generation healthcare and EPSRC grant EP/R006202/1+2 种基金supported by the National NaturalScience Foundation of China(Nos.11520101003 and11861121001)the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDB16010200 and XDB07030300)support from the National Postdoctoral Program for Innovative Talents(No.BX201600106)
文摘A multichannel calorimeter system is designed and constructed which is capable of delivering single-shot and broadband spectral measurement of terahertz(THz) radiation generated in intense laser–plasma interactions. The generation mechanism of backward THz radiation(BTR) is studied by using the multichannel calorimeter system in an intense picosecond laser–solid interaction experiment. The dependence of the BTR energy and spectrum on laser energy, target thickness and pre-plasma scale length is obtained. These results indicate that coherent transition radiation is responsible for the low-frequency component(<1 THz) of BTR. It is also observed that a large-scale pre-plasma primarily enhances the high-frequency component(>3 THz) of BTR.
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.
