The ShenGuang-III (SG-III) laser facility was developed by the laser fusion research center (LFRC) for inertial confinement fusion (ICF) studies in China. Over 80 diagnostics have been installed at the SG-III laser facility, including optical diagnostics, x-ray imaging diagnostics, x-ray spectrum diagnostics, fusion product diagnostics and general diagnostics assistant systems, as well as central control and data acquisition systems. Various ICF experiments have also been performed at the SG-III laser facility. The first experiment explored the laser-target coupling process, including investigations of hohlraum radiation flux and laser energy coupling efficiency. The second experiment explored ablation and implosion physics, including shell asymmetry and implosion trajectory. The third experiment explored stagnation, hotspot dynamics and the nuclear phase of the implosion.

Experimental progress of inertial confinement fusion based at the ShenGuang-III laser facility in China

The ablative expansion of laser-heated materials is important for determining how hohlraum cavities can be utilized for inertial confinement fusion. The utility of a low-density foam layer to reduce the density of the expanding heated hohlraum wall is demonstrated in a series of experiments on the National Ignition Facility. X-ray radiography measurements of the expanding foam-lined Au wall in low aspect-ratio cylindrical geometry are used to compare the impact of Au-doped CH and Ta2O5 foams between 10 and 40 mg/cc on the wall expansion. HYDRA Simulations are used to estimate the x-ray transmission at the 1/4 nc surface, which is important in understanding the absorption of laser light by the plasma. These demonstrate for the first time that a foam layer reduces the expansion of a hohlraum-like target and illustrate that the interplay between the expanding foam plasma and the shock reflected by the hohlraum wall is critical in optimizing foam-liner parameters to achieve the maximum time for a symmetric drive on a capsule.

Experimental demonstration of the reduced expansion of a laser-heated surface using a low density foam layer, pertaining to advanced hohlraum designs with less wall-motion

As an important x-ray source, enhancement of x-ray emissions from laser-produced plasmas is significant for various applications. Due to less expanding kinetic loss, gold foam with low initial density can have an enhanced x-ray conversion efficiency compared with solid-density gold. However, low-Z impurities within gold foam targets will diminish the enhancement remarkably, and should be tightly controlled. This paper presents an experimental study of a high brightness laser plasma soft x-ray source, based on a g gold foam target with negligible impurities irradiated by nanosecond laser pulses with power density around 3 × 10 W at the Shenguang II laser facility. A conversion efficiency, from multi-eV to multi-keV, of % is achieved in the x-ray emissions—about 21% relative enhancement compared with a solid-density gold target, and the highest conversion efficiency for Au foam planar targets yet. Good agreement has been achieved between the semi-analytical model prediction and the experimental results.

https://iopscience.iop.org/article/10.1088/1741-4326/aa9453/pdf

Efficient soft x-ray sources from laser-irradiated gold foam targets with well-controlled impurities

Green light (2ω) has the potential to drive ignition target for laser fusion with significantly more energy than blue light (3ω) and a relatively higher damage threshold for the optic components in the final optic assembly, but it has issues of a relatively low laser to x-ray conversion efficiency and a hard x-ray spectrum as compared to 3ω. In this paper, we propose to drive a foam hohlraum wall with an ignition laser pulse by taking a 4ω laser at the pre-pulse and a 2ω laser at the main-pulse, called as 4ω–2ω ignition pulse. This novel design has the following advantages: (1) benefiting from 2ω of its relatively high energy output and low damage threshold during main-pulse; (2) benefiting from foam in its relatively high laser to x-ray conversion efficiency and relatively low M-band fraction in re-emission; (3) benefiting from 4ω of its low LPI and low M-band fraction during pre-pulse. From our one-dimensional simulations with the Au material, the laser to x-ray conversion in a foam driven by 4ω–2ω puls...

Foam Au driven by 4ω-2ω ignition laser pulse for inertial confinement fusion

Green light (2$\omega$) has the potential to drive ignition target for laser fusion with significantly more energy than blue light (3$\omega$) and a relatively higher damage threshold for the optic components in the final optic assembly, but it has issues of a relatively low laser to x-ray conversion efficiency and a hard x-ray spectrum as compared to 3$\omega$. In this paper, we propose to drive a foam hohlraum wall with an ignition laser pulse by taking a 4$\omega$ laser at the pre-pulse and a 2$\omega$ laser at the main-pulse, called as 4$\omega$ - 2$\omega$ ignition pulse. This novel design has the following advantages: (1) benefiting from 2$\omega$ of its relatively high energy output and low damage threshold during main-pulse, (2) benefiting from foam in its relatively high laser to x-ray conversion efficiency and relatively low M-band fraction in re-emission, (3) benefiting from 4$\omega$ of its low LPI during pre-pulse. From our 1D simulations with Au material, the laser to x-ray conversion in a foam driven by 4$\omega$ - 2$\omega$ pulse has an increase of $28\%$ as compared to a solid target driven by 3$\omega$ with the same pulse shape. The relatively thin optical depth of foam is one of the main reasons for the increase of laser to x-ray conversion efficiency inside a foam target.

Foam Au driven by 4$\omega$ - 2$\omega$ ignition laser pulse for inertial confinement fusion

Experiments have been conducted to compare the re-emission from foam gold with a 0.3 g cc−1 density and solid gold in a SGIII prototype laser facility. Measurements of the re-emission x-ray flux demonstrate that emission is enhanced by the low density foam gold compared to the solid gold under the same conditions. The emission fraction increases with time and is concentrated on soft x-ray flux between 0.1–1 keV. The simulation results with Multi 1D agree with the experimental results. There are potential advantages to using foam walls for improving the emission and soft x-ray flux in hohlraums.

https://iopscience.iop.org/article/10.1088/0029-5515/56/3/036006/pdf

Demonstration of enhancement of x-ray flux with foam gold compared to solid gold

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Ping Li

Author Tools

Chat about Author

Papers

Demonstration of enhancement of x-ray flux with foam gold compared to solid gold