Speaker
Description
TRUST (Tuscia Research University Small Tokamak) is a new university-scale tokamak currently under design at the University of Tuscia (UNITUS).The main parameters are as follows [1,2]:R= 0.32 m, a= 0.11 m, A= 2.80, K≈ 1.7, Ip≈ 0.11 MA, Bt≈ 0.77 T, H98≈ 0.8, βpol(1)≈0.11, li(3)≈0.77 and will be operated with an ohmic power of Pohm = 0.3 MW.
TRUST is scheduled to be deployed in three phases, during which upgrades will include modifications to the magnets and power supply systems. At least four configurations will be explored: single null (SN), double null (DN), upper single null (USN), and limiter [2].
In addition to its academic and educational purposes, the main objective of the device is to achieve a high-power flux density on the targets, enabling the testing of different materials, such as metamaterials (currently studied as potential solutions for DEMO limiter applications [3]) under significant thermal stress. The system is designed to allow easy replacement of plasma-facing components, and the high flexibility of the machine makes it possible to investigate liquid metals as test targets.
Recent 1D analyses, performed through a parameter scan of the electron density at the outer midplane (ne) and the power crossing the separatrix (PSOL), indicate that within the expected operational range, and the calculated heat-decay length of the parallel heat-flux density λq ≈ 5 mm, the maximum perpendicular power flux achievable at the targets is ≈ 4 MW/m² and ≈ 2.5 MW/m² for SN and limiter configurations.
Given the academic nature of the project, the compact environment, and the technological constraints, achieving such a power flux sufficient to test innovative materials represents a significant milestone.
The work presented is aimed to verify the 1D scan results using SOLPS-ITER simulations, to study the expected power flux to the targets in greater detail and with higher accuracy. These simulations will also support the design of the device, both in terms of target geometry and magnetic equilibrium, to achieve the highest possible power flux at the target plates.
Simulations were performed using both the 'standard' SOLPS-ITER version [4] and the new extended (wide) grid version [5], in which the plasma computational mesh extends to the entire vessel wall. The differences and similarities between the results obtained using the two code versions are compared and discussed.
[1]S.Carusotti et al,https://doi.org/10.1016/j.fusengdes.2025.115416
[2]S.Carusotti et al,https://doi.org/10.1016/j.fusengdes.2025.115246
[3]D.Paoletti et al,https://doi.org/10.3390/jne3040028
[4]S.Wiesen et al,https://doi.org/10.1016/j.jnucmat.2014.10.012
[5]W.Dekeyser et al,https://doi.org/10.1016/j.nme.2021.100999