US Patent 8003964 Applying a particle beam to a patient

An apparatus includes a yoke having a first end and a second end. The yoke is configured to hold a device that includes an aperture and a range compensation structure. A catch arm is pivotally secured to the first end of the yoke. The catch arm includes a locking feature. The locking feature and the second end of the yoke interface, respectively, to a first retention feature and a second retention feature defined by the aperture and the range compensation structure. The locking feature is configured to interface to the first retention feature and the second end of the yoke is configured to interface to the second retention feature.