摘要
We present three possible design options of laser plasma acceleration （LPA） for reaching a 100-GeV level energy by means of a multi-petawatt laser such as the 3.5-k J, 500-fs PETawatt Aquitane Laser （PETAL） at French Alternative Energies and Atomic Energy Commission （CEA）. Based on scaling of laser wakefield acceleration in the quasi-linear regime with the normalized vector potential a0 = 1.4（1.6）, acceleration to 100 （130） GeV requires a 30-m-long plasma waveguide operated at the plasma density ne ≈ 7 ×10^15 c^m-3 with a channel depth An/ne = 20%, while a nonlinear laser wakefield accelerator in the bubble regime with a0 〉/ 2 can reach 100 GeV approximately in a 36/a0-m-long plasma through self-guiding. The third option is a hybrid concept that employs a ponderomotive channel created by a long leading pulse for guiding a short trailing driving laser pulse. The detail parameters for three options are evaluated, optimizing the operating plasma density at which a given energy gain is obtained over the dephasing length and the matched conditions for propagation of relativistic laser pulses in plasma channels, including the self-guiding. For the production of high-quality beams with 1%-level energy spread and a llr-mm-mrad- level transverse normalized emittance at 100-MeV energy, a simple scheme based on the ionization-induced injection mechanism may be conceived. We investigate electron beam dynamics and effects of synchrotron radiation due to betatron motion by solving the beam dynamics equations on energy and beam radius numerically. For the bubble regime case with a0 = 4, radiative energy loss becomes 10% at the maximum energy of 90 GeV.
We present three possible design options of laser plasma acceleration （LPA） for reaching a 100-GeV level energy by means of a multi-petawatt laser such as the 3.5-k J, 500-fs PETawatt Aquitane Laser （PETAL） at French Alternative Energies and Atomic Energy Commission （CEA）. Based on scaling of laser wakefield acceleration in the quasi-linear regime with the normalized vector potential a0 = 1.4（1.6）, acceleration to 100 （130） GeV requires a 30-m-long plasma waveguide operated at the plasma density ne ≈ 7 ×10^15 c^m-3 with a channel depth An/ne = 20%, while a nonlinear laser wakefield accelerator in the bubble regime with a0 〉/ 2 can reach 100 GeV approximately in a 36/a0-m-long plasma through self-guiding. The third option is a hybrid concept that employs a ponderomotive channel created by a long leading pulse for guiding a short trailing driving laser pulse. The detail parameters for three options are evaluated, optimizing the operating plasma density at which a given energy gain is obtained over the dephasing length and the matched conditions for propagation of relativistic laser pulses in plasma channels, including the self-guiding. For the production of high-quality beams with 1%-level energy spread and a llr-mm-mrad- level transverse normalized emittance at 100-MeV energy, a simple scheme based on the ionization-induced injection mechanism may be conceived. We investigate electron beam dynamics and effects of synchrotron radiation due to betatron motion by solving the beam dynamics equations on energy and beam radius numerically. For the bubble regime case with a0 = 4, radiative energy loss becomes 10% at the maximum energy of 90 GeV.
基金
supported by the National Natural Science Foundation of China(Nos.10834008,10974214,60921004,and 51175324)
the National"973"Program of China(Nos.2011CB808104,2011CB808100,and 2010CB923203)
supported by Chinese Academy of Sciences Visiting Professorship for Senior International Scientists(No.2010T2G02)
