Abstract: A radiation detection device, system, and method for use in homeland security is disclosed. The device is portable and includes a photomultiplier tube (PMT) connected to an end of a substantially rigid thin-walled aluminum tube. Inside the aluminum tube, a substantially straight scintillating fiber is disposed (so as to be shielded from ambient light), and an end of the scintillating fiber is optically coupled to the PMT. A voltage output signal from the PMT is signal-processed with a filter to remove high-frequency noise (which may arise from solar radiation spikes) and fed to a voltage-responsive alarm or signalling device. The portable device is employed, for example, in baggage and vehicle radiation scanning systems, as well as for large-area radiation mapping and directional radiation sensing.

Abstract: A displacement difference dosimetry method is provided for use with in-vivo scintillating fiber radiation detectors. A scintillating fiber includes an insertion end which is incrementally inserted into a human body using a catheter or hypodermic needle to provide a fixed (but not necessarily known) insertion path. A photomultiplier tube is coupled to the other end of the scintillating fiber and detects both scintillation light and any Cerenkov light for each position of the scintillating fiber insertion end along the fixed insertion path. The change in the amount of light detected by the photomultiplier tube divided by the corresponding amount of change in position of the scintillating fiber insertion end gives a measure of the dose rate at the scintillation fiber tip which is substantially free from the effects of Cerenkov light.

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: 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: A displacement difference dosimetry method is provided for use with in-vivo scintillating fiber radiation detectors. A scintillating fiber includes an insertion end which is incrementally inserted into a human body using a catheter or hypodermic needle to provide a fixed (but not necessarily known) insertion path. A photomultiplier tube is coupled to the other end of the scintillating fiber and detects both scintillation light and any Cerenkov light for each position of the scintillating fiber insertion end along the fixed insertion path. The change in the amount of light detected by the photomultiplier tube divided by the corresponding amount of change in position of the scintillating fiber insertion end gives a measure of the dose rate at the scintillation fiber tip which is substantially free from the effects of Cerenkov light.

Abstract: A process for the production of a YBa.sub.2 Cu.sub.3 O.sub.7-x or YBa.sub.2 Cu.sub.3 O.sub.7-x -AgO superconductor includes: providing the appropriate powder or mix of powders, pressing the powder to form the desired specimen, sintering the specimen to achieve fusion of the powder, heat treating the sintered specimen, and subjecting the specimen to an oxygenation process. The material exhibits bifurcation in its critical current density versus temperature curve.

Abstract: A device having superconductive and resistive states including an element comprising a high temperature superconductive material having a first (high) state with a first (high) critical current density and having a second (low) state with a second (low) critical current density, wherein the second (low) critical current density is less than the first (high) critical current density. A transient pulse generator applies a transient pulse to the element. The transient pulse changes the state of the element between the first (high) and second (low) states, the element being superconductive in the first (high) state, and the element being resistive in the second (low) state. A YBa.sub.2 Cu.sub.3 O.sub.7-x or YBa.sub.2 Cu.sub.3 O.sub.7-x -Ag compound exhibiting bifurcation of its critical current density versus temperature curve. A process for the production of a YBa.sub.2 Cu.sub.3 O.sub.7-x or YBa.sub.2 Cu.sub.3 O.sub.

Abstract: A material phase of quenched YBa.sub.2 Cu.sub.3 O.sub.x exhibits a high dielectric constant (.kappa..apprxeq.700 at room temperature) and is useful in the fabrication of capacitors. A particularly effective method of producing the material phase involves using laser illumination of the YBa.sub.2 Cu.sub.3 O.sub.x to provide the conditions necessary for quenching. Such laser illumination can lead to fine line patterning of electrically resistive and high dielectric constant material from a conducting or superconducting matrix.