Dipole Magnet

Contact:  Alexander Vodopyanov

As a fixed target experiment, PANDA requires excellent momentum reconstruction for particles emitted at forward angles. The forward magnetic spectrometer will allow the reconstruction of charged particle tracks from 0° up to 10° horizontally (5° vertically) with a momentum resolution of ≤ 1%. The central part of this spectrometer will be the large-aperture dipole magnet which will provide a bending power of 2Tm. Particular challenges are the large opening (about 1m x 3m) and the comparably short total length (2.5m) in conjunction with the requirements on stray fields and the accommodation of detectors within the yoke gap. The lamination of the flux return yoke will ensure the required ramping capabilities, so that the magnet can be operated fully synchronous with the High Energy Storage Ring (HESR).

The main parameters are summarised in the table below.

Field integral 2 Tm
Bending variation ≤ ±15%
Vertical Acceptance ±5°
Horizontal Acceptance ±10°
Ramp speed 1.25%/s
Total dissipated power 360 kW
Total Inductance 0.87 H
Stored energy 2.03 MJ
Weight 220 t
Dimensions (H × W × L) 3.88 × 5.3 × 2.5 m
Gap opening (H × W) 0.80 − 1.01 × 3.10 m