Multipacting phenomenon at high electric fields of superconducting cavities

Recently multipacting (MP) recalculation of the TeV Energy Superconducting Linear Accelerator (TESLA) resonator was performed. In addition to the normal MP which occurs at a peak electric field of around 40MV/m for the TESLA cavity, another type of multipacting with resonant electron trajectory that is far from the equator is also seen. It occurs at a gradient around 60MV/m to 70MV/m. This result seems to explain some experimental observations.