Detector collimator for moving filter media
OwnerDavid L. Smithinventor
Life of this patent
Estimating the term…
Abstract
Radioactivity of particles collected on a moving web of filter material is collimated by means of an aperture whose width decreases generally exponentially in the direction of web movement whereby the fractional rate of activity removal that results from web movement is detected as a first order process so that changes in the rate of particle collection can be measured.
Claims17
Apparatus for monitoring the amount of particles containing a radioactive element being deposited over time on a moving web of filter material to detect changes in the rate of particle deposition, comprising a radiation detector facing an area of the web upon the entirety of which area particles are being deposited and having a view of said area of the web upon the entirety of which area particles are being deposited so that radiation detection and particle deposition proceed simultaneously throughout the entire area and a collimator disposed between the detector and the web for limiting the view of the detector, the collimator permitting passage of radiation from the web to the detector only through an aperture which has a width that decreases generally exponentially in the direction of web movement so that there is a constant fractional rate of removal of deposited particles from the view of the detector caused by movement of the web whereby detection is sensitive to quantitative changes in the rate of deposition of particles on the moving web.
A method for monitoring the amount of particles containing a radioactive element deposited over time on a moving web of filter material and for detecting change in the rate of deposition of particles, comprising using a radiation detector having a limited view of an area of the web upon the entirety of which area particles are being deposited so that radiation detection and particle deposition proceed simultaneously throughout the entire area to measure radiation emitted by the particles on the moving web while collimating the radiation emitted for detection of radiation emitted only from said area of the web within the view of the detector which has a width which decreases generally exponentially in the direction of web movement so that there is a constant fractional rate of removal of deposited particles from the view of the detector caused by movement of the web whereby detection is sensitive to quantitative changes in the rate of deposition of particles on the moving web.
A method for monitoring leakage of coolant liquid in a nuclear power plant comprising withdrawing gases from a reactor containment, causing the withdrawn gases to contact a moving web of filter material so that radioactive particles are collected on the web of filter material, using a radiation detector having a limited view of an area of the web upon the entirety of which area particles are being deposited so that radiation detection and particle deposition proceed simultaneously to measure radiation emitted by particles on the web while collimating the radiation emitted for detection of radiation emitted only from said area of the web which has a width which decreases generally exponentially in the direction of web movement so that there is a constant fractional rate of removal of deposited particles from the view of the detector caused by movement of the web whereby detection is sensitive to quantitative changes in the rate of deposition of particles on the moving web.
A radiation collimator comprising a sheet of material formed as a disc which blocks the passage of radiation and having an aperture defined and encompassed within and passing through the disc for the passage of radiation, which aperture has a width which decreases generally exponentially in one direction along a diameter of the disc.
Dependencies are inferred from the claim text.