Sprecher
Beschreibung
The recent progress at the National Ignition Facility (NIF) has sparked fresh excitement around the topic of inertial fusion energy (IFE) [1–5]. However, significant advances are still required before the goal of practical fusion energy can be realised. In particular, while the recently achieved gain of 4 represents an unprecedented milestone [5], it is still short of the minimum value of > 50 likely to be required for a viable fusion reactor [6]. In addition, current target designs are expensive and time-consuming to produce [7], while cost estimates for future fusion reactors require low cost and high repetition rates [8, 9]. Wetted-foam capsules are seen as a promising target solution for future IFE reactors, with the potential to enable high gain performance at low cost. The CH foams used to contain the DT liquid fuel can potentially be 3D printed, which could significantly improve the production rate and cost of such targets compared to conventional DT-ice targets. A variety of designs based on this technology have been proposed, ranging from more conventional designs (where the wetted-foam layer replaces a DT ice layer [10, 11]) to novel dynamic-shell approaches [7, 12]. Despite their potential, the shock response of low-density foams remains poorly characterised, limiting the accuracy of hydrodynamic simulations. Here, I will report experimental measurements of the equation of state (EOS) for silica (SiO2) aerogel and TMPTA plastic foams under laser-driven shock compression, conducted recently at the Vulcan, GEKKO XII and LULI2000 laser facilities [13-15]. Shock pressures between 50 and 160 GPa were achieved, and the corresponding states were determined using standard impedance matching techniques with a quartz reference material.
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[2] A. L. Kritcher et al., Physical Review E 106, 025201 (2022).
[3] A. B. Zylstra et al., Physical Review E 106, 025202 (2022).
[4] A. B. Zylstra et al., Nature 601, 542–548 (2022).
[5] https://lasers.llnl.gov/news/llnl-experts-foster-national-fusion-energy-ecosystem-ife-star-conference
[6] E. M. Campbell et al., “Laser-direct-drive program: Promise, challenge, and path forward”, Matter and Radiation at Extremes 2, 37–54 (2017).
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[10] R. E. Olson et al., Physics of Plasmas 28, 122704 (2021).
[11] R. E. Olson et al., Physical Review Letters 117, 245001 (2016).
[12] I. V. Igumenshchev et al., Physical Review Letters 131, 015102 (2023).
[13] R. Paddock et al., Physical Review E 107, 025206 (2023).
[14] J.J. Lee et al., Physical Review E (under review 2025).
