Dai, JP (reprint author), Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China.
One of the advantages of free electron lasers (FEL) compared to the conventional laser is the possibility of changing the radiation wavelength in a wide range. However, a series of problems arise under the realization of this advantage. In this paper, the problems, related with the adjustment of energy of the BFEL linac, are investigated mainly with the method of simulation. Three adjustment means are discussed, including changing the gradient of accelerator section, the beam phase and the beam current.