Numerical simulation of the diamond window of the synchrotron workstation. Choice of diamond foil thickness (0.2-1.0 mm)
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2023-01-01 |
| Journal | E3S Web of Conferences |
| Authors | M.V. Pukhovoy, V V Vinokurov, Viktor A. Vinokurov, Oleg Kabov |
| Institutions | Institute of Thermophysics |
| Citations | 2 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: High-Power Synchrotron Diamond Windows
Section titled âTechnical Documentation & Analysis: High-Power Synchrotron Diamond WindowsâExecutive Summary
Section titled âExecutive SummaryâThis research details the critical thermal management requirements for Diamond Vacuum Windows (DVW) used in 4th generation synchrotron radiation (SR) workstations, specifically addressing the SKIF facility. 6CCVDâs expertise in high-purity CVD diamond is essential for meeting these extreme specifications.
- Application: Diamond Vacuum Windows (DVW) designed for high-vacuum (10-8 Pa) cutoff in high-power synchrotron beamlines (SKIF, 3 GeV).
- Challenge: Managing extreme heat loads (up to 1.5 kW/cm2) while maintaining minimal thermal deformation (limit: 3.5 ”m) and low thermal stress.
- Solution Architecture: Utilizes high-purity CVD diamond foil (0.2 mm to 1.0 mm thickness) bonded via a liquid metal interface (0.5 mm) to copper flanges featuring high-efficiency mini-channel cooling.
- Performance Target: The design ensures the maximum operating temperature of the diamond plate does not exceed 320° C, providing a twofold safety margin against thermal stresses.
- Material Requirement: Requires high-thermal-conductivity CVD diamond with precise thickness control and ultra-low surface roughness (Ra < 2.4 nm) for optimal heat transfer and optical performance.
- 6CCVD Value Proposition: We provide custom-dimensioned SCD and PCD plates up to 125 mm, polished to Ra < 1 nm, and offer integrated metalization services necessary for robust liquid metal bonding interfaces.
Technical Specifications
Section titled âTechnical SpecificationsâThe following parameters define the operational environment and material requirements for the high-power DVW system:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Synchrotron Generation | 4+ | N/A | SKIF, Novosibirsk |
| Synchrotron Energy | 3 | GeV | SKIF |
| Total Radiation Power (Planned) | ~49 | kW | Superconducting wiggler source |
| Maximum Heat Flux Density | 1.5 | kW/cm2 | Non-uniform distribution on diamond |
| Total Heat Absorption (DVW) | 1290 | W | Heat load to be dissipated |
| Maximum Operating Temperature | 320 | ° C | Required limit for twofold safety margin |
| Maximum Acceptable Deformation | 3.5 | ”m | Limit for thermal deformation of foil |
| Vacuum Requirement | 10-8 | Pa | High vacuum cutoff |
| Diamond Foil Thickness Range | 0.2 to 1.0 | mm | Varied in simulation |
| Liquid Metal Interface Thickness | 0.5 | mm | Used for vacuum sealing and thermal coupling |
| Mini-Channel Dimensions | 0.5x1 | mm2 | Water cooling channels in copper flanges |
| Diamond Emissivity (Δ) | 0.92 | N/A | Polished CVD diamond surface |
Key Methodologies
Section titled âKey MethodologiesâThe numerical simulation focused on optimizing the thermal and mechanical performance of the DVW using advanced computational fluid dynamics (CFD) and finite element analysis (FEA).
- Computational Modeling: Calculations were performed using the ANSYS Fluent package to determine temperature distributions, strains, and thermal stresses.
- Geometric Configuration: The DVW model included a 40 mm diameter diamond plate coupled to copper flanges containing internal mini-channels (0.5x1 mm2) for water cooling.
- Interface Simulation: A 0.5 mm thick layer of liquid metal was modeled between the diamond and copper to simulate vacuum sealing and significantly reduce thermal contact resistance, a critical factor in vacuum optics.
- Heat Load Application: A total heat absorption of 1290 W was applied to the diamond plate, distributed as a non-uniform heat flux (up to 1.5 kW/cm2) over the 30 mm x 3 mm beam area.
- Material Property Dependence: The simulation incorporated temperature-dependent properties for the CVD diamond, including thermal conductivity and heat capacity (Cp).
- Boundary Conditions: Outer boundaries were set to ambient temperature (22° C) and high vacuum conditions, utilizing a diamond emissivity of 0.92.
- Optimization Focus: The study specifically varied the diamond foil thickness (0.2 mm to 1.0 mm) to determine the optimal dimension that satisfies the TMAX (< 320° C) and deformation (< 3.5 ”m) requirements.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & Capabilitiesâ6CCVD is uniquely positioned to supply the high-specification CVD diamond required to replicate and advance this critical synchrotron research. Our capabilities directly address the material purity, dimensional precision, and surface quality demands of high-power optical devices.
Applicable Materials
Section titled âApplicable MaterialsâTo achieve the required thermal conductivity and low absorption necessary for minimizing thermal stress and deformation, 6CCVD recommends the following materials:
- Optical Grade Polycrystalline Diamond (PCD): Ideal for large-area windows (40 mm diameter and larger) requiring high thermal conductivity and precise thickness control (0.2 mm to 1.0 mm). Our PCD offers excellent thermal properties suitable for high-power thermal filters.
- High Purity Single Crystal Diamond (SCD): For applications requiring the absolute lowest absorption coefficient and highest thermal conductivity, especially if the beam energy is sensitive to grain boundaries. 6CCVD can supply SCD up to 500 ”m thick, suitable for the thinner end of the required range (0.2 mm).
- Boron-Doped Diamond (BDD): While not used in this specific optical application, BDD is available for researchers extending this work into electrochemical or sensing applications requiring diamond integration.
Customization Potential
Section titled âCustomization PotentialâThe success of the DVW relies heavily on precise material dimensions, surface preparation, and integration interfaces. 6CCVD offers full customization to meet these stringent requirements:
| Requirement from Paper | 6CCVD Capability | Technical Advantage |
|---|---|---|
| Dimensions | Plates/wafers up to 125 mm (PCD). Thicknesses from 0.1 ”m to 500 ”m (SCD/PCD). | Easily accommodates the 40 mm diameter and 0.2 mm to 1.0 mm thickness range. |
| Surface Roughness | Polishing to Ra < 1 nm (SCD) and Ra < 5 nm (Inch-size PCD). | Meets or exceeds the required average roughness of 2.4 nm, ensuring minimal scattering and optimal thermal contact. |
| Interface Bonding | Custom metalization services (Au, Pt, Pd, Ti, W, Cu). | We can deposit custom refractory metal stacks (e.g., Ti/Pt/Au) onto the diamond surface, ensuring robust, high-integrity bonding necessary for the liquid metal interface and high-vacuum sealing (10-8 Pa). |
| Precision Cutting | Advanced laser cutting and shaping services. | Allows for precise edge preparation and custom geometries required for integration into the copper mini-channel flanges. |
Engineering Support
Section titled âEngineering SupportâThe paper highlights the critical need for âclarifying its physical characteristicsâ after choosing a diamond supplier. 6CCVDâs in-house team of PhD material scientists and engineers specializes in correlating CVD growth parameters with application-specific performance metrics (thermal conductivity, optical absorption, and mechanical strength).
We offer comprehensive engineering support to assist researchers in:
- Material Selection: Determining the optimal balance between SCD and PCD based on specific SR beam energy and required thermal load capacity.
- Thickness Optimization: Providing material data necessary for accurate simulation of heat release dependence on thickness, crucial for achieving the required < 3.5 ”m deformation limit.
- Integration Strategy: Consulting on metalization stack design for reliable, high-vacuum sealing and efficient thermal coupling to the liquid metal interface.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Due to the high energy density in the synchrotron beam and the high cost of all elements of the synchrotron and workstations, due to the fact that most of the devices are in vacuum, as well as high requirements for the smallness of thermal deformations of optical elements, ensuring thermal management of any elements of workstations using synchrotron radiation (SR) is a unique, complex, non-standard task. The work is devoted to the finalizing of the previously performed detailed calculations of the cooling of the most heat-loaded optical elements of workstations of wiggler SR sources - diamond windows that cut off high vacuum (DVW).