Ionizing-radiation beam monitoring system

A transmissive ionizing-radiation beam monitoring system comprising:

• a light-tight enclosure comprising an ultra-thin entrance window and an ultra-thin exit window to an incident ionizing-radiation beam, wherein the entrance window and the exit window are highly transmissive to the incident ionizing-radiation beam and comprise one of a dark colored or black polymer film or metal foil, or a composite polymer-foil combination;
• at least one thin scintillator within the light-tight enclosure that is directly in an incident ionizing-radiation beam path and transmissive to the incident radiation beam;
• at least one ultraviolet (UV) illumination source within the light-tight enclosure facing the scintillator for internal system calibration;
• at least one UV photosensor within the light-tight enclosure positioned to monitor and calibrate the UV illumination source;
• at least one machine vision camera within the light-tight enclosure comprising a camera body and lens system located out of an incident ionizing-radiation beam path;
• and
• a mirror in close proximity to each lens and located out of an incident ionizing radiation beam path and obliquely facing both the lens and the scintillator at an angle, wherein the machine vision camera and its associated close proximity mirror comprises a folded optical system configuration with respect to its view of the scintillator surface to reduce a thickness or depth of the light-tight enclosure.

A method of monitoring a beam of ionizing-radiation, including tracking of beam position, movement, intensity profile, beam fluence and external dosimetry, with a rapid internal calibration system, the method comprising:

• receiving the ionizing-radiation beam in a transmissive thin scintillator enclosed in a light-tight structure with an entrance and exit highly transmissive to an incident ionizing-radiation beam, a folded optical system comprising at least one mirror and one machine vision camera, at least one ultraviolet (UV) illumination source facing the thin scintillator and at least one UV photosensor positioned to monitor the UV source, a computer system comprising a frame grabber and a wired cable or wireless data interface between each machine vision camera and the computer system;
• creating a multitude of emitting photons some of which are captured by the machine vision camera folded optical system in real-time;
• causing a series of streaming images from each machine vision camera to the computer system;
• wherein the computer system processes and analyzes in real-time an image data streaming from the machine vision cameras to track the beam position, movement, intensity profile, beam fluence and external dosimetry;
• wherein the rapid internal calibration system periodically activates the UV-source to illuminate the thin scintillator over its entire active area while the UV-photosensor monitors the UV-source to correct for any UV-source signal drift or instability over time, while the machine vision camera folded optical system streams images of the scintillator photon emission over its active area;
• wherein the computer system compares the machine vision camera digital image output to previously stored digital image output taken of the thin scintillator under the same conditions and in this manner monitors the system stability over time and internally calibrates the system for small changes in performance, and signals when a change in the scintillator component is required according to pre-programmed guidelines, or flag if any other hardware or software problems are detected.