Status and upgrade plan of CAEP THz-FEL facility
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摘要: 中国工程物理研究院太赫兹自由电子激光装置(CAEP THz FEL, CTFEL)是国内唯一运行的基于超导加速器的高平均功率自由电子激光太赫兹源,具有频率连续在线可调(0.1~4.2 THz)、高峰值功率(>0.5 MW)、高平均功率(>10 W)、高重频(54.17 MHz)、短脉冲(~ps)、窄线宽(~2%)、全相干和线性偏振等特点。自2017年出光以来,已稳定运行了四年多,并开展了诸多应用实验研究。为进一步满足用户需求,CTFEL计划升级为一台红外太赫兹自由电子激光装置,电子束能量提升至最大50 MeV,频谱范围拓展至0.1~125 THz,同时,建设材料光谱和生物医学两个实验站。Abstract: The Chinese Academy of Engineering Physics Terahertz Free Electron Laser Facility (CAEP THz FEL, CTFEL) is the only high-average power free electron laser terahertz source based on superconducting accelerators in China, with the advantages of continuously adjustable frequency (0.1−4.2 THz), high peak power (>0.5 MW), high average power (>10 W), high repetition rate (54.17 MHz), short pulse (~ps), narrow bandwidth (~2%), full coherence and linear polarization. Since the first lasing in 2017, it has been running stably for more than four years, and many experimental studies have been carried out. To further meet the demands of users, an upgrade plan for an infrared terahertz free electron laser facility based on CTFEL is proposed, where the electron beam energy is increased to a maximum of 50 MeV, and the spectrum range is expanded to 0.1−125 THz. Meanwhile, two experimental stations for material spectroscopy and biomedicine will be built.
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Key words:
- free electron laser /
- terahertz /
- infrared /
- superconducting accelerator /
- user experimental station
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表 1 CTFEL装置系统参数
Table 1. System parameters of CTFEL facility
injector parameter value SRF accelerator parameter value undulator parameter value laser wavelength/nm 532 working frequency/GHz 1.3 number of periods 42 repetition rate/MHz 54.167 working temperature/K 2 period length/mm 38 gun voltage/kV 320 effective field gradient/(MV/m) 10 gap range/mm 18~32 bunch length/ps ~12 amplitude stability 0.03% optical cavity length/mm 2769 beam current/mA 1~5 phase stability/(°) 0.06 curvature radius/mm 2218 表 2 CTFEL装置太赫兹参数
Table 2. THz parameters of CTFEL facility
parameters values THz FEL frequency range/THz 0.67~4.2 bandwidth/% ~2 macro-pulse average power/W 10~60 macro-pulse repetition rate/Hz 1/5/10/20 macro-pulse length/ms 0.3~8 micro-pulse length/ps <10 micro-pulse repetition rate/MHz 54.17 peak power/MW >0.1 minimum beam size/mm <1 polarization direction/% >99 (horizontal) super-radiation frequency range/THz 0.1~0.7 super-radiation electric field/(MV/cm) ~1 表 3 红外太赫兹自由电子激光装置设计参数
Table 3. Design parameters of the IR-THz FEL facility
electron beams IR-THz FEL maximum energy/MeV 50 frequency range/THz 0.1~125 energy spread/% <0.3 (FWHM) wavelength range/µm 2.4~3000 normalized emittance @100 pC/µm <15 pulse length/ps 0.5~20 bunch charge/pC 50~100 maximum macro-pulse power/W >100 -
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