Mechanical design of thin-film diamond crystal mounting apparatus with optimized thermal contact and crystal strain for coherence preservation x-ray optics

Abstract

A method and mechanical design for a thin-film diamond crystal mounting apparatus for coherence preservation x-ray optics with optimized thermal contact and minimized crystal strain are provided. The novel thin-film diamond crystal mounting apparatus mounts a thin-film diamond crystal supported by a thick chemical vapor deposition (CVD) diamond film spacer with a thickness slightly thicker than the thin-film diamond crystal, and two groups of thin film thermal conductors, such as thin CVD diamond film thermal conductor groups separated by the thick CVD diamond spacer. The two groups of thin CVD film thermal conductors provide thermal conducting interface media with the thin-film diamond crystal. A piezoelectric actuator is integrated into a flexural clamping mechanism generating clamping force from zero to an optimal level.

Claims

1. A thin-film diamond crystal mounting apparatus mounting a thin-film diamond crystal for coherence preservation x-ray optics with optimized thermal contact and minimized crystal strain comprising: a chemical vapor deposition (CVD) diamond film spacer supporting the thin-film diamond crystal; two groups of thin film thermal conductors separated by the CVD diamond film spacer providing thermal conducting interface media with the thin-film diamond crystal; a flexural clamping mechanism coupled to the thin-film diamond crystal; and a piezoelectric actuator integrated into said flexural clamping mechanism generating clamping force from zero to an optimal level.

2. The thin-film diamond crystal mounting apparatus as recited in claim 1, wherein said CVD diamond film spacer having a thickness slightly thicker than the thin-film diamond crystal.

3. The thin-film diamond crystal mounting apparatus as recited in claim 1, wherein said two groups of thin film thermal conductors include thin CVD diamond film thermal conductor groups.

4. The thin-film diamond crystal mounting apparatus as recited in claim 1, wherein said two groups of thin film thermal conductors include thin CVD diamond film thermal conductor groups having thicknesses in a range between 10 microns and 20 microns.

5. The thin-film diamond crystal mounting apparatus as recited in claim 1, further comprising a clamping arm, and wherein said piezoelectric actuator being configured to generate clamping force acting on the thin-diamond crystal through said clamping arm.

6. The thin-film diamond crystal mounting apparatus as recited in claim 1, wherein said flexural clamping mechanism includes a clamping arm mounted on a flexural pivot, said clamping arm engaging said piezoelectric actuator and coupling dynamic clamping force acting on the thin-film diamond crystal.

7. The thin-film diamond crystal mounting apparatus as recited in claim 6, wherein said clamping arm includes an adjusting screw with lock nut to provide initial clamping force manual setup.

8. The thin-film diamond crystal mounting apparatus as recited in claim 1, includes a mounting base and a bottom plate.

9. The thin-film diamond crystal mounting apparatus as recited in claim 8, wherein said mounting base and said bottom plate are formed of oxygen-free copper (OFHC) with a coating formed of nickel and gold for synchrotron radiation applications operating in an ultra-high-vacuum (UHV) environment condition.

10. The thin-film diamond crystal mounting apparatus as recited in claim 8, further comprising a thick CVD diamond thermal conductor, and a plurality of clamping screws to clamp said thick CVD diamond thermal conductor to said mounting base.

11. The thin-film diamond crystal mounting apparatus as recited in, claim 10, wherein the plurality of clamping screws are formed of stainless steel.

12. The thin-film diamond crystal mounting apparatus as recited in claim 8, includes a thermal compound added to an interface of said chemical vapor deposition (CVD) diamond film spacer and the thin-film diamond crystal.

13. The thin-film diamond crystal mounting apparatus as recited in claim 8, wherein said mounting base and said bottom plate are formed of oxygen-free copper (OFHC) with nickel and gold coating.

14. The thin-film diamond crystal mounting apparatus as recited in claim 8, wherein said mounting base and said bottom plate are formed of high strength graphite.

15. The thin-film diamond crystal mounting apparatus as recited in claim 8, wherein said mounting base and said bottom plate are formed of an aluminum alloy.

16. A method for implementing thin-film diamond crystal mounting apparatus for coherence preservation x-ray optics with optimized thermal contact and minimized crystal strain comprising: providing a thin-film diamond crystal; providing a chemical vapor deposition (CVD) diamond film spacer supporting the thin-film diamond crystal; providing two groups of thin film thermal conductors separated by the CVD diamond film spacer providing thermal conducting interface media with the thin-film diamond crystal; providing a flexural clamping mechanism coupled to the thin-film diamond crystal; and providing a piezoelectric actuator integrated into said flexural clamping mechanism generating clamping force from zero to an optimal level.

17. The method as recited in claim 16, wherein providing a chemical vapor deposition (CVD) diamond film spacer supporting the thin-film diamond crystal includes providing said CVD diamond film spacer having a thickness slightly thicker than the thin-film diamond crystal.

18. The method as recited in claim 16, further comprising providing a thermal compound to an edge interface between said CVD diamond film spacer and the thin-film diamond crystal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention together with the above and other objects and advantages may best be understood from the following detailed description of the preferred embodiments of the invention illustrated in the drawings, wherein:

(2) FIGS. 1A and 1B illustrates a prior art diamond-crystal sliding fit holder and mounting method for hard x-ray self-seeding monochromator at the Linac Coherent Light Source (LCLS), at SLAC National Accelerator Laboratory with FIG. 1B providing a detailed view of the prior art diamond-crystal sliding fit holder;

(3) FIG. 2 illustrates a novel thin-film diamond crystal mounting apparatus with dynamic clamping force control to optimize the thermal contact condition with minimized crystal strain in-situ in accordance with preferred embodiments;

(4) FIGS. 3A and 3B illustrate fragmentary sectional views of the novel thin-film diamond crystal mounting apparatus of FIG. 2 to show that the dynamic clamping force acting on a thin-film HPHT diamond-crystal in accordance with preferred embodiments; and

(5) FIGS. 4A, 4B, 4C and 4D illustrate the example novel thin-film diamond crystal mounting apparatus of FIG. 2 in accordance with preferred embodiments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) In the following detailed description of embodiments of the invention, reference is made to the accompanying drawings, which illustrate example embodiments by which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the invention.

(7) The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms a, an and the are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms comprises and/or comprising, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

(8) In accordance with features of the invention, a method and a mechanical design for thin-film diamond crystal mounting apparatus for coherence preservation x-ray optics with optimized thermal contact and minimized crystal strain. This novel mechanical design can be applied to new development in the field of: x-ray optics cavities for hard x-ray free-electron laser oscillators (XFELOs), self-seeding monochromators for hard x-ray free-electron laser (XFEL) with high average thermal loading, high heat load diamond crystal monochromators and beam-sharing/beam-split-and-delay devices for XFEL facilities and Advanced Photon Source (APS) future upgraded high-brightness coherent x-ray source in the MBA lattice configuration.

(9) Having reference now to the drawings, in FIG. 2, there is shown an example thin-film diamond crystal mounting apparatus for coherence preservation x-ray optics with optimized thermal contact and minimized crystal strain generally designated by the reference character 200 in accordance with the preferred embodiment. The thin-film diamond crystal mounting apparatus 200 mounts, for example, a thin-film type-IIa high-pressure high-temperature (HPHT) synthetic diamond-crystal 201.

(10) The novel thin-film diamond crystal mounting apparatus 200 provides dynamic clamping force control to optimize the thermal contact condition with minimized crystal strain in-situ in accordance with preferred embodiments. A prototype of the novel thin-film diamond crystal mounting apparatus 200 has been designed and constructed at the Advanced Photon Source (APS) with clamping force controls from zero to an optimized level for coherence preservation hard x-ray optics applications. The thin-film diamond crystal mounting apparatus 200 includes a mounting base 202 and a bottom plate 204.

(11) Referring also to FIGS. 3A and 3B fragmentary sectional views respectively generally designated 300, and 301 of the novel thin-film diamond crystal mounting apparatus 200 illustrate the dynamic clamping force acting on a thin-film type-IIa HPHT synthetic diamond-crystal 201 in accordance with preferred embodiments.

(12) As best shown in FIGS. 3A and 3B, the novel thin-film diamond crystal mounting apparatus 200 mounts the thin-film type-IIa HPHT synthetic diamond crystal 201 supported by a thick chemical vapor deposition (CVD) diamond film spacer 302, having a thickness slightly thicker than the thin-film type-IIa HPHT synthetic diamond crystal 201, and two groups of thin film thermal conductors 304, 306, such as thin CVD diamond film thermal conductor groups separated by the thick CVD diamond film spacer 302. The two groups of thin film thermal conductors 304, 306 provide thermal conducting interface media with the thin-film type-IIa HPHT synthetic diamond crystal 201.

(13) A novel feature of this new novel thin-film diamond crystal mounting apparatus 200 is its basic crystal mounting mechanism using the two groups of thin film thermal conductors 304, 306 having thicknesses in the range of 10-20 micron, as thermal conducting and interface media with the thin-film type-IIa HPHT synthetic diamond-crystal 201.

(14) Referring also to FIGS. 4A, 4B, 4C and 4D, the example novel thin-film diamond crystal mounting apparatus 200 is illustrated in accordance with preferred embodiments.

(15) A piezoelectric actuator 206 is integrated into a flexural clamping mechanism generally designated by the reference character 208 generating a clamping force from zero to an optimal level. The dynamic clamping force acting on the thin-film type-IIa HPHT synthetic diamond-crystal 201 is generated by the piezoelectric actuator 206 through a clamping arm 210 engaging contact point 211. The flexural clamping mechanism 208 includes the clamping arm 210 mounted on a flexural pivot 212. The clamping arm 210 is coupled to the piezoelectric actuator 206 with an adjusting screw 214 and a lock nut 216 to provide an initial clamping force manual setup. One or more screws 218 are coupled to the thick CVD diamond film spacer 302 clamp the two groups of thin film thermal conductors 304, 306 with the thick CVD diamond film spacer 302 to a thick CVD diamond thermal conductor 222.

(16) As shown on the right side in FIG. 2 and partially illustrated in FIGS. 3A and 3B, there are eight clamping screws 220 to clamp the thick CVD diamond thermal conductor 222 to the mounting base 202. For example, the piezoelectric actuator 206 is implemented with a SmartAct SLC-1720-S linear Piezo nanopositioner manufactured and sold by SmartAct GmbH of Oldenburg, Germany.

(17) As shown in the detailed view 301 in FIG. 3B, an edge interface 308 between mating edges of the thick CVD diamond film spacer 302 includes thin-film type-IIa HPHT synthetic diamond-crystal 201 includes an edge interface 308. In addition to the thermal contact interface between the thin-film type-IIa HPHT synthetic diamond-crystal 201 and the two groups of thin film thermal conductors 304, 306, the thermal interface compound added on the edge interface 308 between the edges of the thin-film type-IIa HPHT synthetic diamond-crystal 201 and the thick CVD diamond film spacer 302 enhances the interface heat transfer coefficient significantly.

(18) Other than the thin film type-IIa HPHT synthetic diamond-crystal 201, and two groups of thin film thermal conductors 304, 306, the choice of the materials to construct the other components of the thin-film diamond crystal mounting apparatus 200 are determined by its operation environment conditions with different applications.

(19) For synchrotron radiation applications operating in an ultra-high-vacuum (UHV) environment condition, the mounting base 202 and bottom plate 204 are made of oxygen-free copper (OFHC) with Nickel and Gold coating. The clamping arm 210 and screws 214, 218, 220 are made of aluminum alloy or stainless steel. Gallium-indium eutectic alloy is added on the edge interface 308 between the thin-film type-IIa HPHT synthetic diamond-crystal 201 and thick CVD diamond film spacer 302 to enhance the interface heat transfer coefficient significantly.

(20) For thin-film diamond crystal mounting apparatus 200 with electron beams nearby applications, such as XFEL self-seeding monochromators with high average thermal loading, high strength graphite, such as Highly Ordered Pyrolytic Graphite (HOPG) or CVD diamond could be used to construct the mounting base 202, bottom plate 204, clamping arm 210, and the like. A Molybdenum radiation shielding cover will be added to protect the piezoelectric actuator 206. Vacuum compatible low-Z-material-based thermal compound is needed to apply on the edge interface 308 between the thin-film type-IIa HPHT synthetic diamond-crystal 201 and thick CVD diamond film spacer 302.

(21) In synchrotron radiation applications with ambient or Helium environment conditions, the mounting base 202 could be made of oxygen-free copper (OFHC) or aluminum alloy. Regular thermal compound could be applied on the edge interface 308 between the thin-film type-IIa HPHT synthetic diamond-crystal 201 and the thick CVD diamond film spacer 302.

(22) While the present invention has been described with reference to the details of the embodiments of the invention shown in the drawing, these details are not intended to limit the scope of the invention as claimed in the appended claims.