X-ray or gamma ray systems or devices – Specific application – Diffraction – reflection – or scattering analysis
Reexamination Certificate
2002-09-13
2004-04-06
Church, Craig (Department: 2882)
X-ray or gamma ray systems or devices
Specific application
Diffraction, reflection, or scattering analysis
C378S085000, C378S145000
Reexamination Certificate
active
06718009
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a new and improved method of making of compound x-ray lenses and a new and improved variable focus x-ray lens assembly.
DESCRIPTION OF THE RELATED ART
X-ray lenses are used to focus x-ray beams produced, for example, with synchrotron and lab-based x-ray sources. X-ray beams can be focused by a variety of mechanisms including mirror, crystals, zone plates, and capillaries. However, since the real part of the index of refraction decrement of materials for x-rays is very, very small, and negative, (~ −10
−8
to −10
−6
) it is necessary, respectively, to use several aligned lenses to affect significant x-ray focusing, and x-ray focusing generally requires concave rather than convex-shaped lenses.
A variety of methods for the fabrication of an x-ray focusing lens system composed of several double-sided concave lenses have been suggested. If one-dimensional focusing is sought, then a substrate with a number of aligned cylindrical holes drilled into it can be used. Presently, cylindrical holes of circular cross-section are used for one-dimensional x-ray focusing because they are easy to make. To reduce spherical aberrations in x-ray focusing, it is better to use parabolic-shaped cylinders, rather than circular. Normal drilling cannot produce non-circular-shaped cylinders. If two-dimensional focusing is desired, then spherical or paraboloidal cavities must be configured.
A principal object of the present invention is to provide a new and improved method of making x-ray lenses and a new variable focus x-ray lens assembly.
It is another object of the invention to provide such method of making x-ray lenses and variable focus x-ray lens assembly that requires no or minimal alignment of individual lenses, has substantially smooth walls, has minimal x-ray absorption, and that is easy and economical to manufacture.
It is another object of the invention to provide such method of making x-ray lenses and variable focus x-ray lens assembly that facilitates forming the x-ray lenses of different materials, the x-ray lenses having arbitrary lens profiles, and the use of an arbitrary number of x-ray lenses for variable focusing.
It is another object of the invention to provide method of making x-ray lenses and variable focus x-ray lens assembly substantially without negative effect and that overcome many of the disadvantages of prior arrangements.
SUMMARY OF THE INVENTION
In brief, a method for producing microstructures for use for x-ray lenses using extrusion techniques and a variable focus x-ray lens assembly are provided. An elongated strip containing a series of aligned cylindrical compound x-ray lenses is formed by extrusion. A predefined lens profile of the cylindrical compound x-ray lenses has, for example, a parabolic profile for x-ray focusing.
In accordance with the invention, the elongated strip contains a series of aligned x-ray lenses formed of selected metals, plastics, ceramics and compounds and produced by an extrusion step. For focusing low to moderate energy x-rays, materials having low atomic numbers are used. The elongated strip of multiple cylindrical x-ray lenses can be cut into multiple, generally uniform small lengths, and positioned within a support member. Cutting the assembled support member and x-ray lenses at a selected angle provides a variable focus x-ray lens assembly.
REFERENCES:
patent: 6091798 (2000-07-01), Nygren et al.
patent: 6269145 (2001-07-01), Piestrup et al.
patent: 6385291 (2002-05-01), Takami
B. Lengeler et al.,“Transmission and gain of singly and doubly focusing refractive x-ray lenses” in J. of Applied Physics, vol. 84, No. 11, pp. 5855-5861 (Dec. 1, 1998).
B. Lengeler et al.,“Imaging by parabolic refractive lenses in the hard X-ray range” in J. Synchroton Rad., 6, pp. 1153-1167 (1999).
B. Lengeler et al., “A microscope for hard x rays based on parabolic compound refractive lenses” in Applied Physics Letters, vol. 74, No. 26, pp. 3924-3926 (Jun. 28, 1999).
J.T. Cremer et al., “Cylindrical compound refractive x-ray lenses using plastic substrates” in Review of Scientific Instruments, vol. 70, No. 9 pp. 3545-3548 (Sep. 1999).
M.A. Piestrup et al., “Two-dimensional x-ray focusing from compound lenses made of plastic”in Review of Scientific Instruments, vol. 71, No. 12 pp. 4375-4379 (Dec. 2000).
R.H. Pantell et al., “The effect of unit lens alignment and surface roughness on x-ray compound lens performance” in Review of Scientific Instruments, vol. 71, No. 1 pp. 48-52 (Jan. 2001).
B. Lengeler et al., “Parabolic refractive X-ray lenses”, in J. Synchroton Rad., 9, pp. 119-124 (2002).
C.G. Schroer et al., “High resolution imaging and lithography with hard x-rays using parabolic compound refractive lenses” in Review of Scientific Instruments, v ol. 73, No. 3 pp. 1640-1642 (Mar. 2002).
Church Craig
Pennington Joan
The University of Chicago
Yun Jurie
LandOfFree
Method of making of compound x-ray lenses and variable focus... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of making of compound x-ray lenses and variable focus..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of making of compound x-ray lenses and variable focus... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3216423