Advanced sample environment for neutron scattering at JRR-3; A Cryogen-free horizontal magnetic field system

Tabata, Chihiro; Takada, Shusuke*; Shimojo, Yutaka; Okawara, Manabu*; Ikeda, Yoichi*; Ino, Takashi*; Kawamura, Seiko   ; Oku, Takayuki   ; Fujita, Masaki*; Kaneko, Koji   

Neutron scattering is a powerful tool to investigate magnetism, and its capabilities are enhanced when combined with a magnetic field, allowing for deeper insights into magnetic materials. Traditionally, such experiments use a vertical field magnet on a triple-axis spectrometer to explore wide Q-omega space at high magnetic fields. However, horizontal field magnets are less common due to limitations like lower maximum fields and restricted access in the horizontal scattering plane. Despite these challenges, there is growing interest in horizontal-field magnets for studying complex magnetic structures, such as topological spin textures, and for unique applications with polarized neutrons, like separating nuclear and magnetic components or detecting magnetic chirality. We have introduced a new horizontal-field system for neutron scattering that features an HTC superconducting magnet and a cryogen-free VTC. The 3T magnet, designed by HTS-110, accommodates a 3He spin filter with a low fringe field and a 60-degree horizontal window for polarization channel px measurements. The VTC fits the magnet's bore and shares sample space with existing VTCs at JRR-3, enabling shared use of sample sticks and 3He inserts. This system provides horizontal fields up to 3 T, temperatures down to 0.3 K, and compatibility with the chopper spectrometer at MLF, J-PARC, for future testing.