Trigger method based on internal bricks within cavities for Linear Transformer Drivers

A novel trigger method based on an internal brick and azimuthal line in cavities is presented for Linear Transformer Drivers (LTD). The triggered brick is similar as the other normal bricks in cavities, which has the same charge voltage and the switch gas pressure. When the switch in triggered brick is closed by an external pulse, a high voltage pulse is produced and transmitted to other bricks along an azimuthal line installed in the middle insulator of cavities. Therefore, one external trigger pulse is enough for a 1 MA LTD cavity. This novel trigger manner has been applied successfully in 800 kA cavity with 36 bricks. Based on this novel trigger manner, a trigger method is proposed for a LTD module with multi-stage cavities stacked in series. Only several upstream cavities are triggered by external trigger pulses, and the residual cavities are triggered by the high pulses produced from the particular-location of upstream cavities. This trigger method will greatly simplify the requirements of trigger system, which has a promising application for future 60-MA LTD accelerator.