The wakefield and energy loss study of micro-bunch trains passing through plasmas

Particle-in-cell simulations are performed to study the wakefield and the energy loss of a train of micro-bunches passing through background plasmas. The wakefield and the energy loss are found to be directly connected to the interval of each micro-bunch. If the interval is once the length of the wakefield wavelength, the wakefield excited by each micro-bunch will be superimposed. The energy loss of the micro-bunch increases along the bunch train. On the other hand, if the interval is 1.5 times the length of the wakefield wavelength, the wakefield almost disappears. Micro-bunches on the odd position of the train will transfer their energies to the plasma, and then, these energies are absorbed by the subsequent even micro-bunches. Thus, the total energy loss of the train is greatly reduced.