Abstract: A gas scintillation detector is designed to provide in-beam absolute dose monitoring for ion beam radiotherapy treatments employing spot or raster beam scanning, especially with microsecond-scale beam pulses. Detection of prompt primary scintillation light emitted by gas molecules excited by beam passage provides electronic signals that can be processed to yield output data proportional to delivered dose up to high dose rates, and that appear quickly enough to provide feedback to influence real-time beam intensity adjustments for subsequent steps in the beam scan. When the scintillation light is collected in multiple photo-detectors, the invention is furthermore capable of measuring spot beam position with spatial resolutions of order one millimeter.

Abstract: A gas scintillation detector is designed to provide in-beam absolute dose monitoring for ion beam radiotherapy treatments employing spot or raster beam scanning, especially with microsecond-scale beam pulses. Detection of prompt primary scintillation light emitted by gas molecules excited by beam passage provides electronic signals that can be processed to yield output data proportional to delivered dose up to high dose rates, and that appear quickly enough to provide feedback to influence real-time beam intensity adjustments for subsequent steps in the beam scan. When the scintillation light is collected in multiple photo-detectors, the invention is furthermore capable of measuring spot beam position with spatial resolutions of order one millimeter.

Abstract: A beam profile measurement detector is a tool to efficiently verify dose distributions created with active methods of a clinical proton beam delivery. A Multi-Pad Ionization Chamber (MPIC) has 128 ionization chambers arranged in one plane and measure lateral profiles in fields up to 38 cm in diameter. The MPIC pads have a 5 mm pitch for fields up to 20 cm in diameter and a 7 mm pitch for larger fields, providing an accuracy of field size determination of about 0.5 mm. The Multi-Layer Ionization Chamber (MLIC) detector contains 122 small-volume ionization chambers stacked at a 1.82 mm step (water-equivalent) for depth-dose profile measurements. The MLIC detector can measure profiles up to 20 cm in depth, and determine the 80% distal dose fall-off with about 0.1 mm precision. Both detectors can be connected to the same set of electronics modules, which form the detectors' data acquisition system.

Abstract: A beam profile measurement detector is a tool to efficiently verify dose distributions created with active methods of a clinical proton beam delivery. A Multi-Pad Ionization Chamber (MPIC) has 128 ionization chambers arranged in one plane and measure lateral profiles in fields up to 38 cm in diameter. The MPIC pads have a 5 mm pitch for fields up to 20 cm in diameter and a 7 mm pitch for larger fields, providing an accuracy of field size determination of about 0.5 mm. The Multi-Layer Ionization Chamber (MLIC) detector contains 122 small-volume ionization chambers stacked at a 1.82 mm step (water-equivalent) for depth-dose profile measurements. The MLIC detector can measure profiles up to 20 cm in depth, and determine the 80% distal dose fall-off with about 0.1 mm precision. Both detectors can be connected to the same set of electronics modules, which form the detectors' data acquisition system.

Abstract: A radiation detector includes a substrate having a cavity defined therein, an anode surface positioned in the bottom of the cavity and a cathode positioned adjacent the cavity opening. A drift electrode is juxtaposed over the substrate opposite the cavity and defines a region containing a gaseous medium. As ionized charge pairs are established in the gaseous medium due to radiation provided by an external radiation source, electrons drift toward the anode under the influence of a first electric field established between the anode and drift electrode. Thereafter, the electron undergoes avalanche multiplication with the gaseous medium in an avalanche region defined by a second intense electric field established between the anode and cathode. The structure of the present invention provides an electric field gradient geometry which permits optimal design of the avalanche region geometry, and which further minimizes photon feedback from the cathode.

Abstract: An optical imaging system includes an array of optical imaging devices each comprising a device for providing charge amplification in a gaseous medium. A preferred embodiment of such a charge amplification device includes a substrate having a cavity defined therein, an anode surface positioned in the bottom of the cavity and a cathode positioned adjacent the cavity opening. A drift electrode is juxtaposed over the substrate opposite the cavity and defines a region containing a gaseous medium. As ionized charge pairs are established in the gaseous medium due to radiation provided by an external radiation source, electrons are attracted toward the anode where they undergo avalanche multiplication with the gaseous medium under the influence of an intense electric field established between the anode and cathode.