| 摘要 |
A variable mode X-ray transmission system is provided that can be operated in low or high dose rate modes depending upon the area or portion of the vehicle to be screened. In one embodiment, variable dose rate is achieved by use of a novel collimator. The systems disclosed in this application enable the scanning of a vehicle cab portion (occupied by people, such as a driver) at low dose rate, which is safe for human beings, while allowing the scanning of the cargo portion (unoccupied by people) at a high dose rate. Rapid switching from low dose rate to high dose rate operating mode is provided, while striking a balance between high material penetration for cargo portion and low intensity exposure that is safe for occupants in the cab portion of the inspected vehicle. |
