Uniform heating of materials into the warm dense matter regime with laser-driven quasimonoenergetic ion beams
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2015-12-01 |
| Journal | Physical Review E |
| Authors | WooâSuk Bang, B. J. Albright, Paul A. Bradley, Erik Vold, J. C. Boettger |
| Institutions | Los Alamos National Laboratory |
| Citations | 32 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Uniform Heating of Diamond for Warm Dense Matter Studies
Section titled âTechnical Documentation & Analysis: Uniform Heating of Diamond for Warm Dense Matter StudiesâExecutive Summary
Section titled âExecutive SummaryâThis research demonstrates a highly effective method for generating uniformly heated Warm Dense Matter (WDM) using laser-driven ion beams, a critical capability for high-energy density physics and planetary science.
- Core Achievement: Successful theoretical modeling and experimental validation of uniform, isochoric heating of solid diamond and gold foils into the WDM regime.
- Diamond Target Specifications: Achieved expected plasma temperatures of 1.7 eV in 15 ”m thick diamond foils, maintaining near-solid density (volume increase estimated at only 2%).
- Heating Mechanism: Utilizes a quasi-monoenergetic aluminum ion beam (140 MeV ±33 MeV) for volumetric energy deposition, ensuring rapid heating (~20 ps) without hydrodynamic expansion.
- Key Material Insight: The inherent finite energy spread (ÎE/E ~20%) of the laser-driven ion beam provides a more uniform stopping power profile across the 15 ”m target depth compared to a perfectly monoenergetic beam.
- Application Relevance: Uniformly heated diamond WDM samples are essential for high-fidelity Equation-of-State (EOS), opacity, and conductivity measurements, crucial for validating models of giant planet interiors.
- 6CCVD Relevance: Replicating and extending this research requires high-purity, precisely dimensioned, thin Single Crystal Diamond (SCD) foils, a core offering of 6CCVD.
Technical Specifications
Section titled âTechnical SpecificationsâThe following table summarizes the critical parameters related to the diamond target and the heating process extracted from the analysis.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Target Material | Diamond (Solid) | N/A | Used for WDM generation studies. |
| Target Thickness | 15 | ”m | Required thickness for uniform heating by 140 MeV Al ions. |
| Incident Ion Energy (Al) | 140 (±33) | MeV | Average kinetic energy of the quasi-monoenergetic beam. |
| Ion Energy Spread (ÎE/E) | ~20 | % | Finite spread found to maximize heating uniformity. |
| Target Incidence Angle | 45 | ° | Angle of ion beam relative to the target normal. |
| Expected Plasma Temperature (Diamond) | 1.7 | eV | Calculated WDM temperature using SESAME EOS tables. |
| Heating Regime | Isochoric | N/A | Rapid heating preventing hydrodynamic expansion. |
| Heating Rise Time | ~20 | ps | Time scale for energy deposition at 2.37 mm distance. |
| Target Volume Increase | 2 | % | Estimated maximum volume change during heating (for diamond). |
| Required Polishing Uniformity | High | N/A | Critical for reliable EOS and stopping power measurements. |
Key Methodologies
Section titled âKey MethodologiesâThe experiment and subsequent analysis relied on precise material handling and advanced simulation techniques to model energy deposition and resulting plasma conditions.
- Ion Beam Generation: A high-intensity laser pulse (60-80 J, 650 fs, 1054 nm, 2x1020 W/cm2) was used to irradiate a 110 nm thick aluminum foil, generating a quasi-monoenergetic Al ion beam.
- Beam Filtering: A 5 ”m thick aluminum filter was strategically placed to block unwanted low-energy components, including laser light, protons (< 0.5 MeV), and low-energy aluminum ions (< 10 MeV).
- Target Geometry: Diamond (15 ”m thick) and Gold (10 ”m thick) foils were positioned 2.37 mm from the ion source, with the ion beam incident at 45°.
- Stopping Power Calculation: The energy loss and deposition uniformity within the target materials were modeled using the Monte Carlo simulation code SRIM (Stopping and Range of Ions in Matter).
- Temperature Calculation: Expected plasma temperatures were derived by converting the calculated energy deposition per atom (6.3 eV/atom for diamond) using established SESAME Equation-of-State (EOS) tables (#7830 and #7834).
- Uniformity Analysis: The robustness of the uniform heating condition was tested by simulating ion beams with ±10% variation in kinetic energy, confirming the stability of the heating profile.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThe successful replication and advancement of WDM experiments using ion beams depend entirely on the quality and precision of the target material. 6CCVD is uniquely positioned to supply the high-specification diamond required for these demanding high-energy density physics applications.
Applicable Materials
Section titled âApplicable MaterialsâTo replicate the 15 ”m diamond foil used in this research, 6CCVD recommends:
- Optical Grade Single Crystal Diamond (SCD): SCD offers the highest purity and structural uniformity, minimizing defects that could introduce non-uniformities during isochoric heating. This material is essential for generating reliable Equation-of-State (EOS) data, where material consistency is paramount.
- Polycrystalline Diamond (PCD): For larger target areas (up to 125 mm diameter) or applications where slightly lower purity is acceptable, 6CCVD can supply high-quality PCD foils.
Customization Potential
Section titled âCustomization PotentialâThe requirements of WDM experimentsâspecifically the need for thin, precise foilsâalign perfectly with 6CCVDâs core manufacturing capabilities:
| Research Requirement | 6CCVD Capability | Technical Advantage |
|---|---|---|
| Precise Thickness Control | SCD and PCD available from 0.1 ”m up to 500 ”m. | We can supply the exact 15 ”m thickness required, or custom thicknesses (e.g., 10 ”m or 20 ”m) for future ion range studies. |
| Surface Quality | SCD polishing to Ra < 1 nm. Inch-size PCD polishing to Ra < 5 nm. | Ultra-smooth surfaces are critical for minimizing scattering and ensuring clean energy coupling in high-intensity laser environments. |
| Custom Dimensions/Geometry | Custom laser cutting and shaping services. | We provide targets cut to specific geometries required for complex vacuum chamber layouts (e.g., mounting foils at a 45° incidence angle). |
| Advanced Target Integration | Internal metalization capabilities (Au, Pt, Ti, Cu, etc.). | If future experiments require integrated diagnostics or conductive layers, 6CCVD can deposit custom metalization stacks directly onto the diamond surface. |
| Global Logistics | Global shipping (DDU default, DDP available). | Ensures rapid and reliable delivery of sensitive, custom diamond targets to international research facilities (e.g., LANL, Trident, NIF). |
Engineering Support
Section titled âEngineering SupportâThe success of achieving uniform heating relies on the precise stopping power characteristics of the target material.
- Material Optimization: 6CCVDâs in-house PhD team specializes in optimizing MPCVD growth parameters to control diamond properties (e.g., density, defect concentration, nitrogen content). This ensures the target material exhibits the exact density and purity required for accurate Warm Dense Matter (WDM) EOS and stopping power measurements.
- Consultation: We offer expert consultation on material selection, helping researchers choose between SCD and PCD based on required purity, size, and cost constraints for similar high-energy density physics projects.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
In a recent experiment at the Trident laser facility, a laser-driven beam of quasimonoenergetic aluminum ions was used to heat solid gold and diamond foils isochorically to 5.5 and 1.7 eV, respectively. Here theoretical calculations are presented that suggest the gold and diamond were heated uniformly by these laser-driven ion beams. According to calculations and SESAME equation-of-state tables, laser-driven aluminum ion beams achievable at Trident, with a finite energy spread of ÎE/EâŒ20%, are expected to heat the targets more uniformly than a beam of 140-MeV aluminum ions with zero energy spread. The robustness of the expected heating uniformity relative to the changes in the incident ion energy spectra is evaluated, and expected plasma temperatures of various target materials achievable with the current experimental platform are presented.