# In-Line Target Production for Laser IFE
## 2 Modeling Results
### Noncontact Accelerating of a Target
These HTSC materials have practically the same values of the critical temperature (T\({}_{\text{c}}\)) and critical magnetic field (B\({}_{\text{c}}\)), but they differ from each other in terms of their densities (Table 4) and the magnetic susceptibility (for Y123 (\(\chi\)\(|\) = 2.5\(\cdot\)10\({}^{-3}\)[28]) and for Gd123 (\(\chi\)\(|\) = 4.5\(\cdot\)10\({}^{-4}\)[29]). Recall that the phenomenon of superconductivity exists only below the values of B\({}_{\text{c}}\) and T\({}_{\text{c}}\)[30]. Figure 3: Noncontact acceleration setup. In (**a**,**b**): permanent magnet guideway (PMG)-system dimensions (as a whole, it lies on a ferromagnetic substrate); in (**c**): a top view of the mutual arrangement of the field coil (1) and the PMG-system (2) of two magnets covered with a ferromagnetic plate; in (**d**): a starting location of the high temperature superconductors (HTSC)-Sabot (3), just before the acceleration, with the directions of the levitation force (vector B2 in parallel to the Z-axis) and of the driving force (vector B1 in parallel to the X-axis), as well as along the acceleration length (X-axis). The experimental setup (Figure 3) operates based on the following effects: the levitation of the HTSC-Sabot is due to the Meissner effect, and the stability of levitation over the PMG system is ensured by vortex pinning [30]. The experiments were made in the mutually normal magnetic fields: the first is **B**1 (from the field coil to move the HTSC-Sabot) directed along the acceleration length, and the second is **B**2 (from the permanent magnets to counteract the gravity) directed normally to the acceleration length (Figure 3c). The PMG-system was optimized in order to achieve simultaneously large levitation forces and stability of the levitation after small perturbations (Figure 3a-c). Figure 3d shows a starting location of the HTSC-Sabot (3) just before the acceleration. A key feature of the proposed PMG-system is that it has a simple arrangement. It is assembled from several individual magnets that allows it to be extended to any required acceleration length and create multi-stage accelerators. We start with a simple case. Figure 4 demonstrates the work of a one-stage accelerator. The HTSC-Sabot obtains a velocity of 1 m/s (Figure 4a) and keeps it over the whole acceleration length (22.5 cm, see Figure 3c). The vertical and horizontal levitating drift is not observed (Figure 4b,4c). The levitation height is \(\sim\)3 mm. A set of control experiments has shown that the HTSCs can be successfully used to maintain a friction-free motion of the HTSC-Sabot over the PMG. Besides, they can provide a required stability of the levitation height over the whole acceleration length due to a flux pinning effect [30] inherent in the interaction between a Type-II superconductor and a permanent magnet. Technologically, the obtained results allow a convenient spacing of the multiple coils (also called a multiple-stages accelerator) and lead to realizing very high velocities of the HTSC-Sabot. In Reference [5], we have reported that, using the MgB\({}_{2}\)-superconducting coils [31] as a driving body, it is possible to achieve the required velocity V\({}_{\text{inj}}\) = 200 m/s without exceeding the acceleration limits (a = 400g \(<\) 500g), as well as the injector requirement of \(\sim\)5 m in length. It operates at a very low temperature (\(\sim\)18 K) allowing no heat energy to be passed into the target from the accelerating medium. For future IFE power plants, the injection velocities of V\({}_{\text{inj}}\) > 200 m/s can be easily achieved because the combination of \"EM-AC + PMG-System\" successfully works as a multiple-stages accelerator. Therefore, our next step is the development of a multiple-stages accelerator. Below we propose a first version of such accelerator (Figure 5). Superconducting sabot includes several HTSC components (Figure 5a). It comprises not only the accelerating HTSC-coils but also the HTSC-plates for providing its stable levitation along the magnetic track (Figure 5b).