PLACET: a Program to Simulate Drive Beams

In the Compact Linear Collider (CLIC), the 30 GHz RF-power used to accelerate the main beam will be obtained by decelerating a drive beam. The stability of this high-intensity low-energy beam is crucial, especially in the decelerator where the energy spread in the bunch train is large and perturbing fields are strong. A program is presented that simulates the drive beam deceleration. It takes the high group velocities of longitudinal and transverse wakefields into account, together with damping of the transverse mode. The effects of a possible non-uniformity of the decelerating field can also be studied. In addition, different beam-based alignment schemes can be simulated.