Abstract: A method and apparatus for the in vivo location and tracking of a radioactive seed source during and after brachytherapy treatment. The method comprises obtaining multiple views of the seed source in a living organism using: 1) a single PSPMT detector that is exposed through a multiplicity of pinholes thereby obtaining a plurality of images from a single angle; 2) a single PSPMT detector that may obtain an image through a single pinhole or a plurality of pinholes from a plurality of angles through movement of the detector; or 3) a plurality of PSPMT detectors that obtain a plurality of views from different angles simultaneously or virtually simultaneously. The plurality of images obtained from these various techniques, through angular displacement of the various acquired images, provide the information required to generate the three dimensional images needed to define the location of the radioactive seed source within the body of the living organism.

Abstract: Stable THz radiation in the multi-watt range, upwards of 2 watts and even up to 100 watts, is produced through the acceleration of electrons in bunches less than about 500 femtoseconds in length as measured at full width and half maximum, at relativistic speeds (>˜40 MeV) and at a high repetition rate (>˜5 MHz) followed by transverse acceleration thereof by a magnetic field to produce the desired THz emission as synchrotron radiation.

Abstract: A high voltage resistor comprising an array of a plurality of parallel electrically connected resistor elements each containing a resistive solution, attached at each end thereof to an end plate, and about the circumference of each of the end plates, a corona reduction ring. Each of the resistor elements comprises an insulating tube having an electrode inserted into each end thereof and held in position by one or more hose clamps about the outer periphery of the insulating tube. According to a preferred embodiment, the electrode is fabricated from stainless steel and has a mushroom shape at one end, that inserted into the tube, and a flat end for engagement with the end plates that provides connection of the resistor array and with a load.

Abstract: An improved method and apparatus increasing the accuracy and reducing the time required to machine materials, surface treat materials, and allow better control of defects such as particulates in pulsed laser deposition. The speed and quality of machining is improved by combining an ultrashort pulsed laser at high average power with a continuous wave laser. The ultrashort pulsed laser provides an initial ultrashort pulse, on the order of several hundred femtoseconds, to stimulate an electron avalanche in the target material. Coincident with the ultrashort pulse or shortly after it, a pulse from a continuous wave laser is applied to the target. The micromachining method and apparatus creates an initial ultrashort laser pulse to ignite the ablation followed by a longer laser pulse to sustain and enlarge on the ablation effect launched in the initial pulse. The pulse pairs are repeated at a high pulse repetition frequency and as often as desired to produce the desired micromachining effect.

Abstract: A Photo-Multiplier Tube (PMT) base for supplying long-term stable power, gain control and output amplification to a PMT. The present PMT base integrates the circuitry required for the dynode stages of the PMT with an amplifying circuit that amplifies the PMT output signals without disturbing the stable power that is required by each of the dynode stages. In operation the PMT base is electrically and mechanically connected to a PMT. The circuits for the dynode stages primarily provide gain control for each dynode stage in the PMT. The amplifying circuit in the PMT base is electrically connected to a dynode, the anode or both a dynode and the anode of the PMT, from which the PMT output signal is received. A PMT high voltage divider supplies the power to the circuitry required for the dynode stages and the amplifying circuit in the PMT base. The PMT base can be replaceable and can replace PMT bases that do not have an integrated amplifier for the PMT output signal.

Abstract: According to the present invention, there is provided a compact source of intense THz radiation comprising a short bunch, low energy particle beam source, an accelerator cavity and an electromagnetic wiggler. Application of state-of-the-art superconducting accelerating structures and beam recirculation allows such a THz radiation source to have a small footprint and high average intensity without the need of the larger equipment necessary to produce the large charge per bunch generally associated with the production of THz radiation. Consequently, low emittance electron beams can be used to produce emitted THz radiation of high average brilliance.

Abstract: In a camera or similar radiation sensitive device comprising a pixilated scintillation layer, a light guide and an array of position sensitive photomultiplier tubes, wherein there exists so-called dead space between adjacent photomultiplier tubes the improvement comprising a two part light guide comprising a first planar light spreading layer or portion having a first surface that addresses the scintillation layer and optically coupled thereto at a second surface that addresses the photomultiplier tubes, a second layer or portion comprising an array of trapezoidal light collectors defining gaps that span said dead space and are individually optically coupled to individual position sensitive photomultiplier tubes. According to a preferred embodiment, coupling of the trapezoidal light collectors to the position sensitive photomultiplier tubes is accomplished using an optical grease having about the same refractive index as the material of construction of the two part light guide.

Abstract: A system for providing high-resolution display for a matrix output device, such as a Photo-Multiplier Tube (PMT) matrix, that requires a substantially less number of amplifiers than prior readout systems. A resistor matrix is coupled directly to the outputs of a matrix output device. The outputs in each row in the matrix are combined and amplified with an amplifier that is at an end of each row. Similarly, the outputs in each column of the matrix are combined and amplified with an amplifier at an end of each column. The amplifiers at the end of each row and column also provide conversion of the signals from a current to a voltage. The converted and amplified signals are then processed, using a simple yet accurate algorithm such as center of gravity interpolation, to determine location and other information. The determined information may relate to detection of photons on the PMTs, for example, and is provided as an output signal from the processing circuitry.

Abstract: The invention described herein combines the structural digital X-ray image provided by conventional stereotactic core biopsy instruments with the additional functional metabolic gamma imaging obtained with a dedicated compact gamma imaging mini-camera. Before the procedure, the patient is injected with an appropriate radiopharmaceutical. The radiopharmaceutical uptake distribution within the breast under compression in a conventional examination table expressed by the intensity of gamma emissions is obtained for comparison (co-registration) with the digital mammography (X-ray) image. This dual modality mode of operation greatly increases the functionality of existing stereotactic biopsy devices by yielding a much smaller number of false positives than would be produced using X-ray images alone.

Abstract: The present invention describes a method for the detection of heat, incipient fire or combustion comprising the steps of: 1) incorporating a temperature-specific indicating agent which emits a specific detectable gas upon attainment of a predetermined temperature in an area where heat or incipient fire is to be detected, 2) providing a gas detector capable of detecting the specifically detectable gas emitted from the temperature-specific indicating agent; 3) detecting the specifically detectable gas; and 4) providing a warning or alarm when the specifically detectable gas reaches a predetermined concentration in the area. There is also disclosed a heat or incipient fire detection system comprising a temperature-specific indicating agent which emits a specific detectable gas upon attainment of a predetermined temperature and a detector for the specifically detectable gas.

Abstract: A flexible and relatively low cost cryogenic conduit is described. The flexible cryogenic conduit of the present invention comprises a first inner corrugated tube with single braided serving, a second outer corrugated tube with single braided serving concentric with the inner corrugated tube, and arranged outwardly about the periphery of the inner corrugated tube and between the inner and outer corrugated tubes: a superinsulation layer; a one half lap layer of polyester ribbon; a one half lap layer of copper ribbon; a spirally wound refrigeration tube; a second one half lap layer of copper ribbon; a second one half lap layer of polyester ribbon; a second superinsulation layer; a third one half lap layer of polyester ribbon; and a spirally wound stretchable and compressible filament.

Abstract: An application accelerator system for monitoring the gain of a free electron laser. Coherent Synchrotron Radiation (CSR) detection techniques are used with a bunch length monitor for ultra short, picosec to several tens of femtosec, electron bunches. The monitor employs an application accelerator, a coherent radiation production device, an optical or beam chopping device, an infrared radiation collection device, a narrow-banding filter, an infrared detection device, and a control.

Abstract: The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly (20) has a superconducting metal-ceramic design. The srf window assembly (20) comprises a superconducting frame (30), a ceramic plate (40) having a superconducting metallized area, and a superconducting eyelet (50) for sealing plate (40) into frame (30). The plate (40) is brazed to eyelet (50) which is then electron beam welded to frame (30). A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided.

Abstract: An improved multi-channel electron multiplier is provided that exhibits zero cross-talk and high rate operation. Resistive material input and output masks are employed to control divergence of electrons. Electron multiplication takes place in closed channels. Several embodiments are provided for these channels including a continuous resistive emissive multiplier and a discrete resistive multiplier with discrete dynode chains interspaced with resistive layers-masks. Both basic embodiments provide high gain multiplication of electrons without accumulating surface charges while containing electrons to their proper channels to eliminate cross-talk. The invention can be for example applied to improve the performance of ion mass spectrometers, positron emission tomography devices, in DNA sequencing and other beta radiography applications and in many applications in particle physics.