Patent Number: 
Section: claims

1. An apparatus directing x-rays along a predetermined axis, said apparatus comprising:an x-ray optic having one or more nested x-ray reflector rings positioned relative to a source generating broad spectrum x-rays so that generated x-rays moving away from the predetermined axis are collected by said reflector incident at or close to a Bragg angle to thereby reflect the collected x-rays into a conically parallel beam;a first diffractor positioned relative to said x-ray optic to receive incident thereon the conically parallel beam, said first diffractor selected from a truncated cone and a cylinder and diffracting the conically parallel beam toward the predetermined axis; anda second diffractor positioned relative to said first diffractor and having a geometry effective to receive incident thereon and redirect the conically parallel beam along the predetermined axis as a collimated beam of substantially parallel x-rays. 2. The apparatus of claim 1, wherein a target lies along the predetermined axis so as to thereon receive the collimated beam of substantially parallel x-rays. 3. The apparatus of claim 1, further comprising a beam block positioned to prevent x-rays from the source other than the diffracted conically parallel beam of x-rays from reaching said second diffractor. 4. The apparatus of claim 1, wherein said x-ray optic has an x-ray grazing incidence reflecting surface along a full figure of revolution geometry effective for collecting a solid angle of x-rays diverging from said source and the solid angle is defined by the formula 2π(cos(Θ1)−cos(Θ2)) so as to collimate the collected x-rays into a conically parallel beam of x-rays. 5. The apparatus of claim 1, wherein said first diffractor comprises a truncated cone having an x-ray diffracting surface along an interior of the cone, the truncated cone optionally having a slit along a full lengthwise dimension. 6. The apparatus of claim 1, wherein said second diffractor comprises a truncated cone having an x-ray diffractive surface along an exterior surface of said truncated cone.