Abstract:
A luminescent body is for an X-ray detector, in particular for an X-ray computer tomograph. It contains a ceramic of the general composition (M1-xLnx)2O2S, M being at least one element selected from the group: Y, La, Sc, Lu and/or Gd, and Ln being at least one element selected from the group: Eu, Ce, Pr, Tb, Yb, Dy, Sm and/or Ho. In order to improve the spatial resolution of the luminescent body, the ceramic is used in the form of fibers, which are connected in a parallel alignment to constitute a fiber plate.
Abstract:
A portable dosimetry system measures individual seed strengths of fully loaded multi-seed holders. The system includes a 5 mm diameter scintillating fiber disposed in a groove on a rigid bed. A photomultiplier tube (PMT) is supported on the rigid bed and is coupled to an end surface of the scintillating fiber. Attachments are provided for positioning multi-seed holders adjacent the peripheral surface of the scintillating fiber, and movable shield plates are provided for inhibiting stray radiation (produced by neighboring seeds) from reaching the scintillating fiber. The system is useful for calibrating 100% of the seeds in a holder in less time than it currently takes to calibrate 10% of the seeds in the holder.
Abstract:
The present invention provides an optical fiber, an optical fiber cable and a radiation detecting system at a low cost. Further, the radiation detecting system is provided which can adequately monitor the radiation leak without delay. The optical fiber cable comprises: an optical fiber including; a core 12 having lightwave guide property and extending along one direction; a clad layer 14 covering over a peripheral surface of the core 12; and a scintillator material dispersed in the clad layer 14 and emitting light when radiation is applied, a radiation-shielding layer 24 covering substantially over a periphery of the optical fiber10, and a gap 26 located in at least one part of the radiation-shielding layer 24. The radiation detecting system comprises an optical fiber cable 20 adapted to emit light at a region where radiation is applied and transmitting the emitted light, photoelectric conversion means 32 connected to at least one end of the optical fiber cable 20, and processing means 38 detecting when radiation is applied in accordance with an output signal of the photoelectric conversion means 32.
Abstract:
A method and apparatus for creating density images of an object through the 3-dimensional tracking of protons that have passed through the object are provided. More specifically, the 3-dimensional tracking of the protons is accomplished by gathering and analyzing images of the ionization tracks of the protons in a closely packed stack of scintillating fibers.
Abstract:
The invention is a real time sensor for therapeutic radiation. A probe is placed in or near the patient that senses in real time the dose at the location of the probe. The strength of the dose is determined by either an insertion or an exit probe. The location is determined by a series of vertical and horizontal sensing elements that gives the operator a real time read out dose location relative to placement of the patient. The increased accuracy prevents serious tissue damage to the patient by preventing overdose or delivery of a dose to a wrong location within the body.
Abstract:
Scintillating optical fiber is used in a probe for detecting radiation. The scintillating optical fiber is fused to an extension fiber leading to optoelectronics such as p-intrinsic n-photodiodes or avalanche photodiodes. The fibers are housed in a durable probe body for penetration into the ground. When radiation is present, dopants in the scintillating fiber emit visible light through the extension fiber to the optoelectronics. Amplifiers are provided for monitoring the light intensity transmitted along the fibers and for triggering an alarm circuit signaling the presence of radiation at the probe.
Abstract:
A very high resolution radiochromatogram for ionizing radiation comprises at least one array made up of a set of filament-like members adapted to enable spatial marking of a surface to be analyzed according to a specific frame of reference and adapted to detect said radiation by scintillation and to transmit light produced by such detection. The array is formed by two groups of optical fibers. Each fiber is disposed along a respective straight line segment defining two orthogonal directions delimiting an analysis plane or surface. At least one of the groups is subdivided into two elementary groups spaced in a direction perpendicular to the analysis plane or surface. The fibers of the elementary groups are parallel.
Abstract:
A large area nuclear detection system with high resolution includes a sensor formed of scintillating optical fibers and a remotely located detector comprising at least a pair of microchannel plate photomultiplier tubes, with the sensitive area of the sensor being many times the area of the detectors. Two linear arrays of optical fibers are arranged orthogonally to define a sensor matrix of rows and columns of fibers. Nuclear radiation from a particle at the sensor is converted to optical energy by the sensor. A microchannel PMT is connected with each array for measuring the optical energy output of the fibers thereof to determine the row and column location of the nuclear particle in accordance with the quantity of energy received from the fibers. Thus, nuclear radiation can be detected over a large area with a high degree of accuracy and resolution. A characterizing feature of the detection system is the conversion of the output of large orthogonally arranged layers of scintillator elements from a long and narrow rectangular format to a square or round output format to match the detector which typically has round or square sensitive areas of a few centimeters.
Abstract:
A nuclear radiation detection system for remote monitoring of movement of nuclear material over a road or highway. Nuclear fiber sensors, which may be several meters long, are covertly positioned in at least two monitoring points, such as buried shallowly under the roadway or hung from a tunnel wall, along the path which a nuclear source may be clandestinely moved. These fiber sensors are individually connected, by an epoxy glue, to individual transmitting optical fibers. Movement of a nuclear radiation source in close proximity to the fiber sensors at the two or more monitoring points produces an optical signal which exceeds a preestablished threshold. These optical signals travel through the transmitting optical fibers, which may be about 1 kilometers long, to a electronic system comprised of a microprocessor controlled signal detecting, signal processing and even data storage means. The optical fibers and electronic system are also selectively hidden from view for security reasons. Any movement of a nuclear source is detected by strength and duration radiation signal data which is stored in the microprocessor memory. This data may be removed from the processor and read out by a data key means.
Abstract:
Apparatus for the remote localization or location of radioactive sources having a pinhole camera, whereof the walls constitute a shield for radioactive radiation, said camera having an opening making it possible to introduce a first film able to detect radioactive radiation emitted by said sources and positioned facing the pinhole, a second film sensitive to visible light at the same location as the first and a plug constituting a shield for the radioactive radiation and used for closing said opening during the operation of the apparatus. Preferably, the pinhole is defined by a double cone. Preferably it constitutes a double diaphragm, a small diaphragm permitting the passage of radioactive radiation and light and a large diaphragm only permitting the passage of radioactive radiation.