Advanced fuel layering in line-moving, high-gain direct-drive cryogenic targets

Abstract

In inertial fusion energy (IFE) research, a number of technological issues have focused on the ability to inexpensively fabricate large quantities of free-standing targets (FSTs) by developing a specialized layering module with repeatable operation. Of central importance for the progress towards plasma generation with intense thermonuclear reactions is the fuel structure, which must be isotropic to ensure that fusion will take place. In this report, the results of modeling the FST layering time, $\unicode[STIX]{x1D70F}_{\text{Form}}$ , are presented for targets which are shells of ${\sim}4~\text{mm}$ in diameter with a wall made from compact and porous polymers. The layer thickness is ${\sim}200~\unicode[STIX]{x03BC}\text{m}$ for pure solid fuel and ${\sim}250~\unicode[STIX]{x03BC}\text{m}$ for in-porous solid fuel. Computation shows $\unicode[STIX]{x1D70F}_{\text{Form}}<23$ s for $\text{D}_{2}$ fuel and $\unicode[STIX]{x1D70F}_{\text{Form}}<30$ s for D–T fuel. This is an excellent result in terms of minimizing the tritium inventory, producing IFE targets in massive numbers ( ${\sim}$ 1 million each day) and obtaining the fuel as isotropic ultrafine layers. It is shown experimentally that such small layering time can be realized by the FST layering method in line-moving, high-gain direct-drive cryogenic targets using $n$ -fold-spiral layering channels at $n=2,3$ .

Improvement of unidirectional scattering characteristics based on multiple nanospheres array

“…In Figure C, the magnitude of main scattering lobe can be further enhanced as the number of nanospheres increases. These results can be applied in ultra‐compact low loss optical devices …”

A high-pinning-Type-II superconducting maglev for ICF target delivery: main principles, material options and demonstration models

“…Using the MgB 2 measurements [13,14] in terms of B 0 and J C , we calculated the acceleration parameters at T S = 20 K for V inj = 200 m/s and M PR = 0.5 g. A reactor-scaled cryogenic target has the (2) diameter ~ 4 mm and the mass of M T ~ 4.5 mg (M T << M PR ), and it can be formed by the FST layering method [7]. The obtained results are presented in Table 3.…”

“…A cost-effective approach for ICF target supply was proposed at the LPI (see Figure 2). It is based on using free-standing and line-moving targets [5][6][7][8] to develop target fabrication and delivery technologies with an emphasis on repetition systems, which is referred to as the FST approach. Figure 2 uses the following notations: 1 -target, 2 -holder (working with a single target), 3 -a batch of free-standing shells filled with fuel, 4 -shell container (SC), 5 -layering module (LM), 6 -layering channel (LC), 7 -test chamber (TC).…”

“…A detailed description of the in-line FST production and multiple target protection methods for target delivery at HRR laser facilities, including the results achieved to date (experimental and theoretical), can be found in Refs. [5][6][7][8].…”

“…where M PR is the mass of the HTSC-projectile, R FC is the field coil radius, R SC is the MgB 2 -coil radius (with a margin R FC /R SC = 5), F pin is the pinning force density and J C is the critical current density, which depends on the external magnetic field in the coil center B 0 and the temperature T S of HTSC. Using the MgB 2 measurements [13,14] in terms of B 0 and J C , we calculated the acceleration parameters at T S = 20 K for V inj = 200 m/s and M PR = 0.5 g. A reactor-scaled cryogenic target has the diameter of approximately 4 mm and the mass of M T ~4.5 mg (M T << M PR ), and it can be formed by the FST layering method [7] . The obtained results are presented in Table 3.…”