We recently did the mechanical construction and machining for a device called Pastis3 for Institut Laue Langevin.
The Pastis3/PANTHER insert represents the third generation of the PASTIS device, enabling XYZ neutron polarization analysis as an optional upgrade for existing ILL (Institut Laue Langevin) instruments equipped with wide-angle detector coverage. PASTIS-3 utilizes two polarized 3He Neutron Spin Filter Cells (NSF) for the polarization and analysis of neutron spins, flipping the polarization of the incident neutron beam by reversing the spin state of the 3He in the polarizing entrance cell.
The XYZ technique requires the ability to rotate the magnetic field in any direction, requiring a highly homogeneous magnetic field to achieve long relaxation times for the 3He NSF. In the PASTIS3/PANTHER insert, the magnetic field is generated by two primary pairs of water-cooled coils, each with a typical diameter of 700 mm, which must be precisely positioned within a few tens of millimetres. The entire system is housed within a vacuum chamber, and the coil sets can rotate along the Z-axis.
To meet these requirements, the mechanical construction and machining must be extremely precise and constructed from fully non-magnetic materials. The parts have wall thickness as small as 0,5 mm and cutting tools as long as 1,5 meters.
Additionally, ensuring airtightness presents another significant challenge.
If you want to know more about the Pastis3, you can read the scientific paper here: 1-s2.0-S016890022100543X-main
