X-FEL Quadrupole with Gradient of 100 T/m

The paper describes an XFEL quadrupole with a gradient of 100 T/m. The magnets of this quadrupole are designed for installation in the free space between the XFEL undulators to maintain the high quality of the electron beam at an energy of 10 - 20 GeV, which requires high stability of the magnetic axis of the lens. The available size of the aperture of the lens is R = 8 mm. The stability of the quadrupole magnetic axis is better than 5 um for ±10% of the gradient range; the magnetic field quality is good (ΔВ/В < 10-3).