Patent ID: 7692154

Claim:
A lightweight collimator, having at least a top and a bottom and incorporating shielding about a cylindrical detector having at least a top and a bottom, said detector affixed near said top of said collimator for collecting collimated radiation through said bottom of said collimator, at least said shielding shaped externally according to the quartic relationship: L 0 2 = y 2 + [ y 2 ⁢ z 2 ( y + D ) 2 ] where y is the minimum thickness of encased shielding needed to shield said collimator from un-collimated radiation entering said collimator at a distance, z, along said longitudinal axis of said collimator, z measured from the bottom of said detector, and D is the inner diameter of said collimator as established by the outer diameter of said detector, wherein at least said shielding incorporated in said collimator has a variable wall thickness that decreases gradually from a thickness L 0 at the end of said collimator containing said detector to a thickness, y, measured at a distance, z, away from the bottom of said detector.