Abstract: A system includes a cylindrical phantom and a conical structure disposed in the phantom. The conical structure is shaped as a frustum and emits Cherenkov radiation when exposed to ionizing radiation. The system can be used for calibration of an MR-Linac system by exposing the system to ionizing radiation. The Cherenkov radiation can be imaged during exposure to ionizing radiation.

Abstract: A monitor for pulsed high energy radiation therapy using a radiation beam passing through a treatment zone, the radiation of 0.2 MEV or greater; has a camera for imaging Cherenkov light from the treatment zone; apparatus for preventing interference by room lighting, the camera synchronized to pulses of the radiation beam; and an image processor adapted to determine extent of the beam area on the patient skin from the images. Additionally an image processor determines cumulative skin dose in the treatment zone from the images. In embodiments, the processor uses a three-dimensional model of a subject to determine mapping of image intensity in images of Cherenkov light to radiation intensity in skin, applies the mapping to images of Cherenkov light to verify skin dose delivered, and accumulates skin dose by summing the maps of skin dose.

Abstract: A monitor for pulsed high energy radiation therapy using a radiation beam passing through a treatment zone, the radiation of 0.2 MEV or greater; has a camera for imaging Cherenkov light from the treatment zone; apparatus for preventing interference by room lighting, the camera synchronized to pulses of the radiation beam; and an image processor adapted to determine extent of the beam area on the patient skin from the images. Additionally an image processor determines cumulative skin dose in the treatment zone from the images. In embodiments, the processor uses a three-dimensional model of a subject to determine mapping of image intensity in images of Cherenkov light to radiation intensity in skin, applies the mapping to images of Cherenkov light to verify skin dose delivered, and accumulates skin dose by summing the maps of skin dose.

Abstract: Drive circuits for a flat panel display using a matrix of DC responsive phosphor dots are disclosed. Enabled row conductors receive a pulse of DC potential equal to +HV, whereas disabled row conductors receive +HV/.sub.2. Enabled column conductors receive zero potential, whereas disabled column conductors receive +HV/.sub.2. HV is in the range 90 to 140V. This allows semiconductor integrated circuit display drivers to be used in conjunction with the column conductors. Discrete transistor complementary-pair drivers are used for the row conductors. Scanning and character generation functions are achieved by the use of semiconductor integrated circuits. A pulse-width brightness control operates by selection of one of several logical combinations of the outputs of a counter. Two or four column driver circuits are provided to simplify high density connection problems and a divider circuit causes the column driver circuits to be addressed in sequence.