Abstract: Multi-leaf collimators have a guide frame (1) with a plurality of metal plates (3) arranged in a displaceable fashion, by which each individual metal plate can be displaced by an electric motor (M), with the electric motor (M) being a rotary electromechanical motor (M), which operates according to the form-fit principle, with electromechanical actuators.

Abstract: The present invention relates to a high pressure sodium lamp comprising an evacuated cover including a base part, an arc tube comprising a first and a second electrode each being connected to the base part via conductor members. At least one conductor member is arranged isolated by a shielding member for preventing, during operation of the high pressure sodium lamp, the photo electronic stream from the at least one conductor member to the arc tube. The lamp comprises a second arc tube.

Abstract: Multi-leaf collimators have a guide frame (1) with a plurality of metal plates (3) arranged in a displaceable fashion, by which each individual metal plate can be displaced by an electric motor (M), with the electric motor (M) being a rotatory electromechanical motor (M), which operates according to the form-fit principle, with electromechanical actuators.

Abstract: The present invention relates to a high pressure sodium lamp comprising an evacuated cover including a base part, an arc tube comprising a first and a second electrode each being connected to the base part via conductor members. At least one conductor member is arranged isolated by a shielding member for preventing, during operation of the high pressure sodium lamp, the photo electronic stream from the at least one conductor member to the arc tube. The lamp comprises a second arc tube.

Abstract: The motors of a multi-leaf collimator for driving the leaves are tilted away from horizontal. The motors are oriented at an angle upwards from the top or downwards from the bottom of a plane formed by the leaves of the multi-leaf collimator. By tilting or angling the motors relative to the multi-leaf collimator, motors with a single standard or a few different shaft lengths may be used. The motors may be more tightly packed, allowing for shorter leaves. Since Tungsten is expensive, costs may be saved by the shortening of the leaves. Standardization of the motor parts may also reduce costs. Due to the reduced weight of the resulting multi-leaf collimator, wear of the bearings of the linac or gantry arm may be reduced.