Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B5/00—Optical elements other than lenses
  • G02B5/08—Mirrors
  • G02B5/0883—Mirrors with a refractive index gradient
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
  • B82Y10/00—Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B5/00—Optical elements other than lenses
  • G02B5/08—Mirrors
  • G02B5/0891—Ultraviolet [UV] mirrors
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21K—HANDLING OF PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
  • G21K1/00—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating
  • G21K1/06—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating using diffraction, refraction or reflection, e.g. monochromators
  • G21K1/062—Devices having a multilayer structure
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21K—HANDLING OF PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
  • G21K2201/00—Arrangements for handling radiation or particles
  • G21K2201/06—Arrangements for handling radiation or particles using diffractive, refractive or reflecting elements
  • G21K2201/061—Arrangements for handling radiation or particles using diffractive, refractive or reflecting elements characterised by a multilayer structure
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21K—HANDLING OF PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
  • G21K2201/00—Arrangements for handling radiation or particles
  • G21K2201/06—Arrangements for handling radiation or particles using diffractive, refractive or reflecting elements
  • G21K2201/067—Construction details

Definitions

• the present invention relates to an electromagnetic optic element. More specifically the present invention relates to reflective multilayer x-ray optics having adjustable working wavelengths.
• X-ray optics are used in many applications such as x-ray diffraction analysis and spectroscopy that require the directing, focusing, collimation, or monochromatizing of x-ray energy from an x-ray source.
• the family of x-ray optics or reflectors used in such applications presently include: total reflection mirrors having a reflective surface coated with gold, copper, nickel, platinum, and other similar elements; crystal diffraction elements such as graphite; and multilayer structures.
• the reflective surfaces in the present invention are configured as multilayer or graded-d multilayer x-ray reflective surfaces.
• Multilayer structures only reflect x-ray radiation when Bragg's equation is satisfied:
• Multilayer or graded-d multilayer reflectors/mirrors are optics which utilize their inherent multilayer structure to reflect narrow band or monochromatic x-ray radiation.
• the multilayer structure of the present invention comprises light element layers of relatively low electron density alternating with heavy element layers of relatively high electron density, both of which define the d-spacing of the multilayer.
• the bandwidth of the reflected x-ray radiation can be customized by manipulating the optical and multilayer parameters of the reflector.
• the d spacing may be changed depthwise to control the bandpass of the multilayer mirror.
• the d-spacing of a multilayer mirror can also be tailored through lateral grading in such a way that the Bragg condition is satisfied at every point on a curved multilayer reflector.
• Curved multilayer reflectors including parabolic, elliptical, and other aspherically shaped reflectors must satisfy Bragg's law to reflect a certain specific x-ray wavelength (also referred to as energy or frequency). Bragg's law must be satisfied at every point on a curvature for a defined contour of such a reflecting mirror. Different reflecting surfaces require different d-spacing to reflect a specific x-ray wavelength. This means the d-spacing should be matched with the curvature of a reflector to satisfy Bragg's law such that the desired x-ray wavelength will be reflected. Since Bragg's law must be satisfied, the incident angle and d-spacing are normally fixed and thus the reflected or working wavelength is fixed.
• the present invention is a multilayer x-ray reflector/mirror which may be used to reflect multiple x-ray wavelengths.
• the multilayer structure has a laterally graded d-spacing.
• the working (reflected) wavelength of the multilayer reflector may be changed by simply varying its curvature and thus the angle of incidence for an x-ray beam to satisfy Bragg's law.
• an electromagnetic reflector has a fixed curvature and a multilayer structure that has been configured to include a plurality of distinct d- spacings.
• the multilayer structure has also been laterally graded such that the electromagnetic reflector may reflect multiple x-ray wavelengths according to Bragg's law.
• the lateral grading of the d-spacings have been configured in conjunction with the curvature of the multilayer coating to reflect a plurality of x-ray wavelengths.
• an electromagnetic reflector is formed with stripe-like multilayer coating sections.
• Each of the coating sections has a fixed curvature and graded d-spacing tailored to reflect a specific wavelength.
• the mirror or x-ray source need to be moved relative to each other so that the appropriate coating section is aligned with the x-ray source.
• Figure 1 is a cross-sectional diagrammatic view of a multilayer Bragg reflector
• Figure 2 is a cross-sectional diagrammatic view of a multilayer reflector with a plurality of distinct d-spacings to reflect multiple x-ray wavelengths
• Figure 3 is a cross-sectional view of a parabolically shaped reflector
• Figure 4 is a cross-sectional view of an elliptically shaped reflector
• Figure 5 is a magnified cross-sectional view taken within circle 5 of Figure 3
• Figure 6 is a magnified cross-sectional view taken within circle 6 of Figure 3
• Figure 7 is a magnified cross-sectional view taken within circle 7 of Figure 4;
• Figure 8 is a magnified cross-sectional view taken within circle 8 of Figure 4;
• Figure 9 is a diagrammatic view of the first embodiment of the reflector of the present invention illustrating its variable curvature and ability to reflect different x-ray wavelengths;
• Figure 10 is a diagrammatic view of a bender used in the present invention;
• Figure 11 is a cross sectional view of the second embodiment of the reflector of the present invention having a fixed curvature that is configured to include a plurality of distinct d-spacings and laterally graded such that it may reflect multiple x-ray wavelengths; and
• Figure 12 is a top view of the third embodiment of the reflector of the present invention with stripe-like sections having different d-spacings such that the reflector can reflect a plurality of x-ray frequencies.
• FIG. 1 is a cross-sectional diagrammatic view of a multilayer reflector 10.
• the multilayer reflector 10 is deposited on a substrate 12 and comprises a plurality of layer sets with a thickness d.
• Each layer set 14 is made up of two separate layers of different materials; one with a relatively high electron density and one with a relatively low electron density.
• x-ray radiation 13 is incident on the multilayer reflector 10 and narrow band or generally monochromatic radiation 16 is reflected according to Bragg's law.
• Figure 2 is a cross sectional diagram of a multilayer structure 18 having a plurality of distinct d-spacings d1 and d2 varying in the depth direction and defined as depth grading.
• the multilayer structure 18 because of the distinct d-spacings d1 and d2 may reflect multiple x-ray wavelengths (i.e. different groups of d-spacing to satisfy a discrete range of reflected wavelengths).
• polychromatic x-ray radiation 20 is incident on the surface of the multilayer structure 18 and low energy x-rays 22 are reflected by the relatively thicker d-spacings d2 and high energy x-rays 24 are reflected by the relatively thinner d-spacings d1.
• Figures 3 and 4 are cross-sectional diagrams of fixed curvature multilayer optics 26 and 28 which generally reflect only one x-ray wavelength.
• Figure 3 illustrates the parabolically shaped multilayer optic 26 which collimates x-ray beams generated by an idealized point x-ray source 30 and
• Figure 4 illustrates the elliptically shaped multilayer optic 28 which focuses x-ray beams generated by an x-ray source 32 to a focal point 34.
• the curvature and d-spacing of optics 26 and 28 have been permanently configured to satisfy Bragg's law for a specific wavelength at every point on the surface of the optics 26 and 28.
• Figures 5, 6, 7, and 8 are cross-sectional magnified views of the multilayer surfaces taken within circles 5, 6, 7, and 8 of Figures 3 and 4. From these figures the variation in incident angle and the lateral grading of the d-spacing in order to satisfy Bragg's law for a specific frequency can be seen.
• the parabolic optic 26 includes incident angle ⁇ , and d-spacing d3 at one area of its surface and incident angle ⁇ 2 and d-spacing d4 at another area. While these parameters are different, the result is that these areas reflect generally the same x-ray wavelength following Bragg's law.
• the elliptical optic 28 includes incident angle ⁇ 3 and d- spacing d5 at one area of its surface and incident angle ⁇ 4 and d-spacing d6 at another area which reflect the same x-ray wavelength.
• the shortcomings with these type of fixed curvature reflectors is that they may only be used to reflect a single x-ray wavelength or narrow band.
• multilayer reflectors require different d-spacing variations to reflect different x-ray wavelengths at the same incident angle and the d- spacing should match the surface curvature (angle of incidence) to reflect x-rays according to Bragg's law.
• the present invention provides electromagnetic reflectors which may be used to reflect a plurality of x-ray wavelengths having substantially no overlap.
• a first embodiment of the present invention shown by Figure 8 comprises a multilayer reflector with variable curvature and a laterally graded d-spacing. If a multilayer is a flat reflector with uniform d-spacing, the flat reflector can be rotated to reflect x-rays of different wavelengths, as the incidence angle will vary. If a multilayer has a curved surface the d-spacing must be laterally graded to satisfy Bragg's law at every point. Thus, the d-spacing or incidence angle may be changed to vary the x-ray wavelength reflected from a multilayer reflector.
• the laterally graded d- spacing of a multilayer reflector may remain constant while only the curvature is varied and the curvature of a multilayer reflector may remain constant and have multiple graded d-spacings such that multiple x-ray wavelengths may be reflected by the multilayer reflector.
• either the d-spacing variation of the multilayer coating or the curvature of the optics can be manipulated such that the multilayer optics reflect x-rays with different wavelengths.
• the d-spacing is given by: (1 )
• ⁇ is the incident angle. It can be shown that the sin ⁇ can be written, at a very accurate approximation, as a product of a factor "C" (an arbitrary constant) and common form which is independent from the x-ray energy. The same d-spacing can be used for different wavelengths by changing the factor C such that ⁇ /C is a constant. Accordingly, sin ⁇ , which is determined by the configuration of the reflection surface, can be maintained the same if d-spacing is proportionally changed with the wavelength such that :
• p is the parabolic parameter.
• the accurate incident angle can be given by the following formula: p generally is a number on the order of .1 and x is generally in the range of several tens of millimeters to more than 100 millimeters. Due to the fact that ⁇ is small where tan ⁇ « ⁇ , the incident angle can be written as:
• d-spacing is determined by:
• d-spacing is defined as well as the wavelength dependency on d-spacing for a multilayer reflector.
• the "real d-spacing", or the “geometric d-spacing is different from the "first order Bragg d-spacing” due to the effects of refraction in the multilayer structure.
• a multilayer optic is used as a first order Bragg reflector. This is the reason that "d-spacing" is commonly defined and measured by the first order Bragg's law.
• Such defined d-spacing is the same for different wavelengths as shown in the following discussion.
• variable curvature multilayer reflector 36 is shown in two positions 38 and 40 having two different curvatures defined by the ellipses 33 and 35 and reflecting different x-ray wavelengths 39 and 41 to a focal point 31.
• a similar scheme may be configured for parabolic collimating mirrors which conform to two different parabolas.
• the reflector 36 has more curvature at position 38 then at position 40. The increased curvature will allow the reflector to reflect larger x-ray wavelengths at position 38 then at position 40.
• the reflector at position 40 is modified with less curvature then at position 38 and will reflect shorter x-ray wavelengths.
• the curvature of the reflector 36 is exaggerated in Figure 9 to help illustrate the curvature at the alternate positions 38 and 40.
• the manipulation of the parabolic parameter p of the parabolic reflector and the minor radius b of the elliptical reflector may be adjusted to vary the wavelength of the reflected x-rays.
• a four point bender 42 is shown in Figure 10 having precision actuators 44a and
• the bender 42 will vary the parabolic parameter p of a parabolically shaped multilayer reflector and the minor radius b of an elliptically shaped multilayer reflector as detailed above.
• a multilayer reflector 46 of fixed curvature with a plurality of distinct d-spacings d7 and d8, is configured to reflect multiple x-ray wavelengths.
• Each d-spacing d7 and d8 will satisfy Bragg's law for a specific x-ray wavelength.
• the relatively larger d-spacing d8 will reflect longer wavelengths and the relatively shorter d-spacing d7 will reflect shorter wavelengths.
• the reflected wavelengths will have substantially no overlap. Since the absorption for lower energy (longer wavelength) x-rays is stronger, the reflection layer d8 for the lower energy x-rays should be the top layers on the reflector 46.
• the d-spacings d7 and d8 are laterally graded in cooperation with the curvature of the reflector 46 to satisfy Bragg's law for a plurality of specific x-ray wavelengths.
• additional groups of d-spacings may be used limited only by the dimensions and structure of the reflector 46.
• a multilayer reflector 48 having stripe like sections 50 with different d- spacings is shown.
• Each stripe 50 has a d-spacing configured to reflect specific x-ray wavelengths.
• An x-ray source 52 needs only to be translated relative to the stripe like sections 50 of the reflector 48 to change the wavelength of the x-rays reflected from the reflector 48.
• the preferred method of translation is to fix the position of the x-ray source 52 while translating the reflector 48.

Landscapes

• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Nanotechnology (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Crystallography & Structural Chemistry (AREA)
• Mathematical Physics (AREA)
• Theoretical Computer Science (AREA)
• High Energy & Nuclear Physics (AREA)
• General Engineering & Computer Science (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Optical Elements Other Than Lenses (AREA)
• Analysing Materials By The Use Of Radiation (AREA)
• Aerials With Secondary Devices (AREA)
• Spectrometry And Color Measurement (AREA)
• Mechanical Light Control Or Optical Switches (AREA)
• Optical Filters (AREA)
• Semiconductor Lasers (AREA)
• Investigating Or Analysing Materials By Optical Means (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (3)

Family

ID=23441383

Family Applications (1)

Country Status (9)

Cited By (6)

Families Citing this family (36)

Family Cites Families (35)

• 1999
  • 1999-08-02 US US09/366,028 patent/US6421417B1/en not_active Expired - Lifetime
• 2000
  • 2000-08-01 CZ CZ20020791A patent/CZ301738B6/cs not_active IP Right Cessation
  • 2000-08-01 AT AT00952405T patent/ATE280993T1/de not_active IP Right Cessation
  • 2000-08-01 DE DE60015346T patent/DE60015346T2/de not_active Expired - Lifetime
  • 2000-08-01 CA CA002642736A patent/CA2642736A1/en not_active Abandoned
  • 2000-08-01 WO PCT/US2000/021060 patent/WO2001009904A2/en not_active Ceased
  • 2000-08-01 JP JP2001514437A patent/JP2003506732A/ja active Pending
  • 2000-08-01 EP EP00952405A patent/EP1200967B1/en not_active Expired - Lifetime
  • 2000-08-01 AU AU65111/00A patent/AU6511100A/en not_active Abandoned
  • 2000-08-01 CA CA002380922A patent/CA2380922C/en not_active Expired - Lifetime

Also Published As

Similar Documents

Legal Events