Detector & Imaging Group Patents

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  • 2015, December: Method and apparatus to image biological interactions in plants
    Patent Number: 9,217,744
    Category: Plant Biology
    Inventors: Weisenberger, Andrew ; Bonito, Gregory M. ; Reid, Chantal D. ; Smith, Mark Frederick

    A method to dynamically image the actual translocation of molecular compounds of interest in a plant root, root system, and rhizosphere without disturbing the root or the soil. The technique makes use of radioactive isotopes as tracers to label molecules of interest and to image their distribution in the plant and/or soil. The method allows for the study and imaging of various biological and biochemical interactions in the rhizosphere of a plant, including, but not limited to, mycorrhizal associations in such regions.
  • 2015, September: Method for passively compensating for temperature coefficient of gain in silicon photomultipliers and similar devices
    Patent Number: 9,123,611
    Category: Detector Instrumentation
    Inventors: McKisson, John E. ; Barbosa, Fernando

    A method for designing a completely passive bias compensation circuit to stabilize the gain of multiple pixel avalanche photo detector devices. The method includes determining circuitry design and component values to achieve a desired precision of gain stability. The method can be used with any temperature sensitive device with a nominally linear coefficient of voltage dependent parameter that must be stabilized. The circuitry design includes a negative temperature coefficient resistor in thermal contact with the photomultiplier device to provide a varying resistance and a second fixed resistor to form a voltage divider that can be chosen to set the desired slope and intercept for the characteristic with a specific voltage source value. The addition of a third resistor to the divider network provides a solution set for a set of SiPM devices that requires only a single stabilized voltage source value.
  • 2015, September: Upconverting nanoparticles for optimizing scintillator based detection systems
    Patent Number: 8,536,532
    Category: Detector Instrumentation
    Inventors: Kross, Brian ; McKisson, John E ; McKisson, John ; Weisenberger, Andrew ; Xi, Wenze ; Zorn, Carl

    An upconverting device for a scintillation detection system is provided. The detection system comprises a scintillator material, a sensor, a light transmission path between the scintillator material and the sensor, and a plurality of upconverting nanoparticles particles positioned in the light transmission path.
  • 2013, May: Upconverting device for enhanced recogntion of certain wavelengths of light
    Patent Number: 8,444,264
    Category: Detector Instrumentation
    Inventors: Kross, Brian ; McKIsson, John ; McKisson, John ; Weisenberger, Andrew ; Xi, Wenze ; Zorn, Carl

    An upconverting device for enhanced recognition of selected wavelengths is provided. The device comprises a transparent light transmitter in combination with a plurality of upconverting nanoparticles. The device may a lens in eyewear or alternatively a transparent panel such as a window in an instrument or machine. In use the upconverting device is positioned between a light source and the eye(s) of the user of the upconverting device.
  • 2012, December: Method for image reconstruction of moving radionuclide source distribution
    Patent Number: 8,335,363
    Category: Medical
    Inventors: Stolin, Alexander V. ; McKisson, John E. ; Lee, Seung Joon ; Smith, Mark Frederick

    A method for image reconstruction of moving radionuclide distributions. Its particular embodiment is for single photon emission computed tomography (SPECT) imaging of awake animals, though its techniques are general enough to be applied to other moving radionuclide distributions as well. The invention eliminates motion and blurring artifacts for image reconstructions of moving source distributions. This opens new avenues in the area of small animal brain imaging with radiotracers, which can now be performed without the perturbing influences of anesthesia or physical restraint on the biological system.
  • 2012, October: Imaging method for monitoring delivery of high dose rate brachytherapy
    Patent Number: 8,295,910
    Category: Medical
    Inventors: Weisenberger, Andrew G ; Majewski, Stanislaw

    A method for in-situ monitoring both the balloon/cavity and the radioactive source in brachytherapy treatment utilizing using at least one pair of miniature gamma cameras to acquire separate images of: 1) the radioactive source as it is moved in the tumor volume during brachytherapy; and 2) a relatively low intensity radiation source produced by either an injected radiopharmaceutical rendering cancerous tissue visible or from a radioactive solution filling a balloon surgically implanted into the cavity formed by the surgical resection of a tumor.
  • 2012, July: Collimator with attachment mechanism and system
    Patent Number: 8,217,359
    Category: Medical
    Inventors: Kross, Brian J. ; McKisson, John ; Stolin, Aleksandr ; Weisenberger, Andrew G. ; Zorn, Carl

    A self-aligning collimator for a radiation imaging device that is secured and aligned through the use of a plurality of small magnets. The collimator allows for the rapid exchange, removal, or addition of collimators for the radiation imaging device without the need for tools. The accompanying method discloses the use of magnets and accompanying magnetic fields to align and secure collimators in a radiation imaging assembly.
  • 2012, May: Positron emission tomography and optical tissue imaging
    Patent Number: 8,183,530
    Category: Medical
    Inventors: Falen, Steven W. ; Hoefer, Richard A. ; Majewski, Stanislaw ; McKisson, John ; Kross, Brian ; Proffitt, James ; Stolin, Alexander ; Weisenberger, Andrew G.

    A mobile compact imaging system that combines both PET imaging and optical imaging into a single system which can be located in the operating room (OR) and provides faster feedback to determine if a tumor has been fully resected and if there are adequate surgical margins. While final confirmation is obtained from the pathology lab, such a device can reduce the total time necessary for the procedure and the number of iterations required to achieve satisfactory resection of a tumor with good margins.
  • 2012, March: Radio frequency phototube
    Patent Number: 8,138,460
    Category: Detector Instrumentation
    Inventors: Margaryan, Amur ; Gynashyan, Karlen ; Hashimoto, Osamu ; Majewski, Stanislaw ; Tang, Linguang ; Marikyan, Gagik ; Marikyan, legal representative, Lia

    A method and apparatus of obtaining a record of repetitive optical or other phenomena having durations in the picosecond range, comprising a circular scan electron tube to receive light pulses and convert them to electron images consisting with fast nanosecond electronic signals, a continuous wave light or other particle pulses, e.g. electron picosecond pulses, and a synchronizing mechanism arranged to synchronize the deflection of the electron image (images) in the tube (tubes) with the repetition rate of the incident pulse train. There is also provided a method and apparatus for digitization of a repetitive and random optical waveform with a bandwidth higher than 10 GHz.
  • 2011, December: High-resolution single photon planar and SPECT imaging of brain and neck employing a system of two co-registered opposed gamma imaging heads
    Patent Number: 8,071,949
    Category: Medical
    Inventors: Majewski, Stanislaw ; Proffitt, James

    A compact, mobile, dedicated SPECT brain imager that can be easily moved to the patient to provide in-situ imaging, especially when the patient cannot be moved to the Nuclear Medicine imaging center. As a result of the widespread availability of single photon labeled biomarkers, the SPECT brain imager can be used in many locations, including remote locations away from medical centers. The SPECT imager improves the detection of gamma emission from the patient's head and neck area with a large field of view. Two identical lightweight gamma imaging detector heads are mounted to a rotating gantry and precisely mechanically co-registered to each other at 180 degrees. A unique imaging algorithm combines the co-registered images from the detector heads and provides several SPECT tomographic reconstructions of the imaged object thereby improving the diagnostic quality especially in the case of imaging requiring higher spatial resolution and sensitivity at the same time.
  • 2011, November: Method and apparatus for real time imaging and monitoring of radiotherapy beams
    Patent Number: 8,049,176
    Category: Medical
    Inventors: Majewski, Stanislaw ; Proffitt, James ; Macey, Daniel J. ; Weisenberger, Andrew G.

    A method and apparatus for real time imaging and monitoring of radiation therapy beams is designed to preferentially distinguish and image low energy radiation from high energy secondary radiation emitted from a target as the result of therapeutic beam deposition. A detector having low sensitivity to high energy photons combined with a collimator designed to dynamically image in the region of the therapeutic beam target is used.
  • 2011, September: Imaging system for cardiac planar imaging using a dedicated dual-head gamma camera
    Patent Number: 8,017,916
    Category: Medical
    Inventors: Majewski, Stanislaw; Umeno, Marc M.

    A cardiac imaging system employing dual gamma imaging heads co-registered with one another to provide two dynamic simultaneous views of the heart sector of a patient torso. A first gamma imaging head is positioned in a first orientation with respect to the heart sector and a second gamma imaging head is positioned in a second orientation with respect to the heart sector. An adjustment arrangement is capable of adjusting the distance between the separate imaging heads and the angle between the heads. With the angle between the imaging heads set to 180 degrees and operating in a range of 140-159keV and at a rate of up to 500kHz, the imaging heads are co-registered to produce simultaneous dynamic recording of two stereotactic views of the heart. The use of co-registered imaging heads maximizes the uniformity of detection sensitivity of blood flow in and around the heart over the whole heart volume and minimizes radiation absorption effects. A normalization/image fusion technique is implemented pixel-by-corresponding pixel to increase signal for any cardiac region viewed in two images obtained from the two opposed detector heads for the same time bin. The imaging system is capable of producing enhanced first pass studies, bloodpool studies including planar, gated and non-gated EKG studies, planar EKG perfusion studies, and planar hot spot imaging.
  • 2011, February: Compact and mobile high resolution PET brain imager
    Patent Number: 7,884,331
    Category: Medical
    Inventors: Majewski, Stanislaw; Proffitt, James

    A brain imager includes a compact ring-like static PET imager mounted in a helmet-like structure. When attached to a patient's head, the helmet-like brain imager maintains the relative head-to-imager geometry fixed through the whole imaging procedure. The brain imaging helmet contains radiation sensors and minimal front-end electronics. A flexible mechanical suspension/harness system supports the weight of the helmet thereby allowing for patient to have limited movements of the head during imaging scans. The compact ring-like PET imager enables very high resolution imaging of neurological brain functions, cancer, and effects of trauma using a rather simple mobile scanner with limited spaceneeds for use and storage.
  • 2010, December: Dedicated mobile high resolution prostate PET imager with an insertable transrectal probe
    Patent Number: 7,858,944
    Category: Medical
    Inventors: Majewski, Stanislaw ; Proffitt, James

    A dedicated mobile PET imaging system to image the prostate and surrounding organs. The imaging system includes an outside high resolution PET imager placed close to the patient's torso and an insertable and compact transrectal probe that is placed in close proximity to the prostate and operates in conjunction with the outside imager. The two detector systems are spatially co-registered to each other. The outside imager is mounted on an open rotating gantry to provide torso-wide 3D images of the prostate and surrounding tissue and organs. The insertable probe provides closer imaging, high sensitivity, and very high resolution predominately 2Dview of the prostate and immediate surroundings. The probe is operated in conjunction with the outside imager and a fast data acquisition system to provide very high resolution reconstruction of the prostate and surrounding tissue and organs.
  • 2010, June: High resolution PET breast imager with improved detection efficiency
    Patent Number: 7,732,774
    Category: Medical
    Inventors: Majewski, Stanislaw

    A highly efficient PET breast imager for detecting lesions in the entire breast including those located close to the patient's chest wall. The breast imager includes a ring of imaging modules surrounding the imaged breast. Each imaging module includes a slant imaging light guide inserted between a gamma radiation sensor and a photodetector. The slant light guide permits the gamma radiation sensors to be placed in close proximity to the skin of the chest wall thereby extending the sensitive region of the imager to the base of the breast. Several types of photodetectors are proposed for use in the detector modules, with compact silicon photomultipliers as the preferred choice, due to its high compactness. The geometry of the detector heads and the arrangement of the detector ring significantly reduce dead regions thereby improving detection efficiency for lesions located close to the chest wall.
  • 2008, October: Method to improve cancerous lesion detection sensitivity in a dedicated dual-head scintimammography system
    Patent Number: 7,444,009
    Category: Medical
    Inventors: Kieper, Douglas Arthur ; Majewski, Stanislaw ; Welch, Benjamin L.

    An improved method for enhancing the contrast between background and lesion areas of a breast undergoing dual-head scintimammographic examination comprising: 1) acquiring a pair of digital images from a pair of small FOV or mini gamma cameras compressing the breast under examination from opposing sides; 2) inverting one of the pair of images to align or co-register with the other of the images to obtain co-registered pixel values; 3) normalizing the pair of images pixel-by-pixel by dividing pixel values from each of the two acquired images and the co-registered image by the average count per pixel in the entire breast area of the corresponding detector; and 4) multiplying the number of counts in each pixel by the value obtained in step 3 to produce a normalization enhanced two dimensional contrast map. This enhanced (increased contrast) contrast map enhances the visibility of minor local increases (uptakes) of activity over the background and therefore improves lesion detection sensitivity, especially of small lesions.
  • 2007, April: Anatomic and functional imaging of tagged molecules in animals
    Patent Number: 7,209,579
    Category: Pre-clinical
    Inventors: Weisenberger, Andrew G. ; Majewski, Stanislaw ; Paulus, Michael J. ; Gleason, Shaun S.

    A novel functional imaging system for use in the imaging of unrestrained and non-anesthetized small animals or other subjects and a method for acquiring such images and further registering them with anatomical X-ray images previously or subsequently acquired. The apparatus comprises a combination of an IR laser profilometry system and gamma, PET and/or SPECT, imaging system, all mounted on a rotating gantry, that permits simultaneous acquisition of positional and orientational information and functional images of an unrestrained subject that are registered, i.e. integrated, using image processing software to produce a functional image of the subject without the use of restraintsor anesthesia. The functional image thus obtained can be registered with a previously or subsequently obtained X-ray CT image of the subject. The use of the system described herein permits functional imaging of a subject in an unrestrained/non-anesthetized condition thereby reducing the stress on the subject and eliminating any potential interference with the functional testing that such stress might induce.
  • 2005, January: Apparatus and method for high dose rate brachytherapy radiation treatment
    Patent Number: 6,847,838
    Category: Medical
    Inventors: Macey, Daniel J.; Majewski, Stanislaw; Weisenberger, Andrew G.; Smith, Mark Frederick; Kross, Brian James

    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 ofviews 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.
  • 2004, June: Optical coupler
    Patent Number: 6,750,456
    Category: Detector Instrumentation
    Inventors: Majewski, Stanislaw; Weisenberger, Andrew G.

    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 positionsensitive 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.
  • 2003, November: Directional intraoperative probe
    Patent Number: 6,643,538
    Category: Medical
    Inventors: Majewski, Stanislaw; Popov, Vladimir; Loutts, Georgii

    An introperative surgical probe incorporating both a fiber optic imaging system and multi-element beta/gamma radiation directional indicating system is described.
  • 2002, January: Slant-hole collimator, dual mode sterotactic localization method
    Patent Number: 6,424,693
    Category: Medical
    Inventors: Weisenberger, Andrew G.

    The use of a slant-hole collimator in the gamma camera of dual mode stereotactic localization apparatus allows the acquisition of a stereo pair of scintimammographic images without repositioning of the gamma camera between image acquisitions.
  • 2002, January: Dual mode stereotactic localization method and application
    Patent Number: 6,389,098
    Category: Medical
    Inventors: Keppel, Cynthia E. ; Barbosa, Fernando Jorge ; Majewski, Stanislaw

    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 thanwould be produced using X-ray images alone. The ability to obtain both the X-ray mammographic image and the nuclear-based medicine gamma image using a single device is made possible largely through the use of a novel, small and movable gamma imaging camera that permits its incorporation into the same table or system as that currently utilized to obtain X-ray based mammographic images for localization of lesions.
  • 2001, January: Gamma-ray blind beta particle probe
    Patent Number: 6,317,622
    Category: Medical
    Inventors: Weisenberger, Andrew G.

    An intra-operative beta particle probe is provided by placing a suitable photomultiplier tube (PMT), micro channel plate (MCP) or other electron multiplier device within a vacuum housing equipped with: 1) an appropriate beta particle permeable window; and 2) electron detection circuitry. Beta particles emitted in the immediate vicinity of the probe window will be received by the electron multiplier device and amplified to produce a detectable signal. Such a device is useful as a gamma insensitive, intra-operative, beta particle probe in surgeries where the patient has been injected with a beta emitting radiopharmaceutical. The method of use of such a device is also described, as is a position sensitive such device.
  • 2001, January: Mini gamma camera, camera system and method of use
    Patent Number: 6,271,525
    Category: Medical
    Inventors: Majewski, Stanislaw ; Weisenberger, Andrew G. ; Wojcik, Randolph F.

    A gamma camera comprising essentially and in order from the front outer or gamma ray impinging surface: 1) a collimator, 2) a scintillator layer, 3) a light guide, 4) an array of position sensitive, high resolution photomultiplier tubes, and 5) printed circuitry for receipt of the output of the photomultipliers. There is also described, a system wherein the output supplied by the high resolution, position sensitive photomultipiler tubes is communicated to: a) a digitizer and b) a computer where it is processed using advanced image processing techniques and a specific algorithm to calculate the center of gravity of any abnormalityobserved during imaging, and c) optional image display and telecommunications ports.
  • 1999, September: Radiology utilizing a gas multiwire detector with resolution enhancement
    Patent Number: 5,960,057
    Category: Medical
    Inventors: Majewski, Stanislaw ; Majewski, Lucasz A.

    This invention relates to a process and apparatus for obtaining filmless, radiological, digital images utilizing a gas multiwire detector. Resolution is enhanced through projection geometry. This invention further relates to imaging systems for X-ray examination of patients or objects, and is particularly suited for mammography.
  • 1999, January: Flexible, liquid core light guide with focusing and light shaping attachments
    Patent Number: 5,896,483
    Category: Detector Instrumentation
    Inventors: Wojcik, Randolph Frank ; Majewski, Stanislaw ; Zorn, Carl John ; Kross, Brian

    A liquid light guide system for ultraviolet light is disclosed that has a light shaping arrangement for the emitted light, a stable liquid core and sheath and reliable and effective end closures. The end closures include a metal crimping arrangement that utilizes two layers of deformable materials to prevent cracking of endplugs.
  • 1999, January: Compact, high-resolution, gamma ray imaging for scintimammography and other medical diagostic applications
    Patent Number: 5,864,141
    Category: Medical
    Inventors: Majewski, Stanislaw ; Weisenberger, Andrew G. ; Wojcik, Randolph F. ; Steinbach, Daniela

    A high resolution gamma ray imaging device includes an aluminum housing, a lead screen collimator at an opened end of the housing, a crystal scintillator array mounted behind the lead screen collimator, a foam layer between the lead screen collimator and the crystal scintillator array, a photomultiplier window coupled to the crystal with optical coupling grease, a photomultiplier having a dynode chain body and a base voltage divider with anodes, anode wire amplifiers each connected to four anodes and a multi pin connector having pin connections to each anode wire amplifier. In one embodiment the crystal scintillator array includes ayttrium aluminum perovskite (YAP) crystal array. In an alternate embodiment, the crystal scintillator array includes a gadolinium oxyorthosilicate (GSO) crystal array.
  • 1998, January: Liquid-core light guide designed to withstand interior bubble formation from temperature-induced volumetric variations
    Patent Number: 5,859,946



    Category: Detector Instrumentation
    Inventors: Randolph Frank Wojcik, Stanislaw Majewski, Carl John Zorn

    A termination for a light guide having optical cladding tubing and a liquid core includes a volumetric change device configured to allow fluid flow out of the tubing whenever the liquid core expands and to allow fluid flow into the tubing whenever the liquid core contracts, an end plug fixed to the tubing to retain the liquid in the liquid core within the tubing and the end piece and a crimping piece for holding the end plug in place.
  • 1998, January: Illuminating system and method for specialized and decorative lighting using liquid light guides
    Patent Number: 5,799,124
    Category: Detector Instrumentation
    Inventors: Zorn, Carl J. ; Kross, Brian J. ; Majewski, Stanislaw ; Wojcik, Randolph F.

    The present invention comprises an illumination system for specialized decorative lighting including a light source, a flexible plastic tube sheath for distributing the light to a remote location, a transparent liquid core filling the tube that has an index of refraction greater than that of the plastic tube and an arrangement where light coupled from the light source is caused to leak from the liquid light guide at desired locations for the purposes of specialized lighting, such as underwater illumination in swimming pools.
  • 1998, January: Dual energy scanning beam laminographic x-radiography
    Patent Number: 5,742,660
    Category: Detector Instrumentation
    Inventors: Majewski, Stanislaw ; Wojcik, Randolph F.

    A multiple x-ray energy level imaging system includes a scanning x-ray beam and two detector design having a first low x-ray energy sensitive detector and a second high x-ray energy sensitive detector. The low x-ray energy detector is placed next to or in front of the high x-ray energy detector. The low energy sensitive detector has small stopping power for x-rays. The lower energy x-rays are absorbed and converted into electrical signals while the majority of the higher energy x-rays pass through undetected. The high energy sensitive detector has a large stopping power for x-rays as well as it havinga filter placed between it and the object to absorb the lower energy x-rays. In a second embodiment; a single energy sensitive detector is provided which provides an output signal proportional to the amount of energy in each individual x-ray it absorbed. It can then have an electronic threshold or thresholds set to select two or more energy ranges for the images. By having multiple detectors located at different positions, a dual energy laminography system is possible.
  • 1997, January: Flexible liquid core light guide with focusing and light shaping attachments
    Patent Number: 5,684,908
    Category: Detector Instrumentation
    Inventors: Kross, Brian J. ; Majewski, Stanislaw ; Zorn, Carl J. ; Majewski, Lukasz A.

    A liquid light guide system for ultraviolet light is disclosed that has a light shaping arrangement for the emitted light, a stable liquid core and sheath and reliable and effective end closures.
  • 1996, January: Examination system utilizing ionizing radiation and a flexible, miniature radiation detector probe
    Patent Number: 5,568,532
    Category: Detector Instrumentation
    Inventors: Majewski, Stanislaw ; Kross, Brian J. ; Zorn, Carl J. ; Majewski, Lukasz A.

    An optimized examination system and method based on the Reverse Geometry X-Ray.RTM. (RGX.RTM.) radiography technique are presented. The examination system comprises a radiation source, at least one flexible, miniature radiation detector probe positioned in appropriate proximity to the object to be examined and to the radiation source with the object located between the source and the probe, a photodetector device attachable to an end of the miniature radiation probe, and a control unit integrated with a display device connected to the photodetector device. The miniature radiation detector probe comprises a scintillation element, a flexible light guide having a first endoptically coupled to the scintillation element and having a second end attachable to the photodetector device, and an opaque, environmentally-resistant sheath surrounding the flexible light guide. The probe may be portable and insertable, or may be fixed in place within the object to be examined. An enclosed, flexible, liquid light guide is also presented, which comprises a thin-walled flexible tube, a liquid, preferably mineral oil, contained within the tube, a scintillation element located at a first end of the tube, closures located at both ends of the tube, and an opaque, environmentally-resistant sheath surrounding the flexible tube. The examination system and method have applications in non-destructive material testing for voids, cracks, and corrosion, and may be used in areas containing hazardous materials. In addition, the system and method have applications for medical and dental imaging.
  • 1995, January: Non cross talk multi-channel photomultiplier using guided electron multipliers
    Patent Number: 5,453,609
    Category: Detector Instrumentation
    Inventors: Gomez, Javier ; Majewski, Stanislaw ; Weisenberger, Andrew G.

    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.