Hadron therapy is a cancer treatment that employs hadrons: a crucial component of a treatment facility is the gantry, a rotating machine that irradiates the patient from multiple angles, significantly improving treatment effectiveness. Currently, several initiatives are developing the first European ion gantry using superconducting magnets to reduce both weight and cost compared to existing ones. Among these initiatives, the EuroSIG project is working on new technologies for this gantry, including the development of bending superconducting magnets that guide the particles toward the patient, facing the challenge of combining strong curvature, moderate ramp rate and conduction cooling. The project is manufacturing a demonstrator magnet for this application, which will first be tested in a helium bath. The design, however, is also compatible with a subsequent test in conduction, marking the first step toward developing the prototype. This paper presents the preliminary design of the conduction cooling system of the EuroSIG dipole magnet, including both the demonstrator and prototype, and its integration into the mechanical structure designed by INFN-Genoa. This work constitutes the first step in assessing the feasibility of conduction cooling for this novel magnet layout. Experimental validation of the proposed cooling concept, assembly and manufacturing approach will be the subject of future activities.
We theoretically study the influence of an external magnetic field on spin-density-wave (SDW) and charge-density-wave (CDW) orders in underdoped iron pnictides within a model that excludes superconducting pairing. We use Zubarev’s single-particle Green’s function technique to solve the mean-field Hamiltonian and calculate the correlation functions and self-consistent temperature-dependent order parameters. Our results suggest that both SDW and CDW can coexist over a finite range of interaction strengths, with stability depending on the relative coupling strengths. The corresponding energy gaps and transition temperatures of CDW and SDW orders are found to vary systematically as a function of interaction strength. The application of an external magnetic field progressively suppresses both SDW and CDW orders, demonstrating the field sensitivity of the coupled density-wave phases. The coexistence of SDW and CDW arises from their mutual self-consistent coupling, while the external magnetic field modifies the quasiparticle spectrum through Zeeman splitting. The electronic density of states exhibits Zeeman splitting, resulting in spin-resolved quasiparticle spectra, redistribution of the density of states (DOS) near the Fermi level, and magnetic-field-induced spin-dependent shifts of the bands.
