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
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.
