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FAIR – the Facility for Antiproton and Ion Research is a new international accelerator facility which is built in Darmstadt, Germany. The core machines of the project are the superconducting synchrotron SIS100 and the superconducting fragment separator Super–FRS. Design and construction of superconducting machines require a comprehensive study of cases when the superconducting state is lost (quench). This dissertation covers two subjects. The first subject aims the development of a novel calculation tool (called GSI quench software) dedicated to the quench study of the FAIR magnets. Quench calculations done with the GSI software serve as an input for the proper design of SIS100 and Super–FRS quench detection and energy extraction systems. The software uses the unconditionally stable implicit scheme for the solution of the partial–differential equations that describe the thermal model of the coil. An innovative adaptive time stepping algorithm is used in order to limit the maximum temperature increase of the individual mesh elements to a predefined level. The thermal model of the coil gives the possibility to include the cooling by a liquid helium bath. The electrical circuit topology including the magnet protection system (energy extraction resistors and/or by–pass diodes) is implemented. The properties of the magnet’s yoke are taken into account in the inductance function Ld(I). The implemented electro–thermal model was verified and validated by comparison to quench measurements conducted on SIS100 dipole and Super–FRS dipole prototypes. The testing campaign on the SIS100 dipole prototype (magnet training, quench propagation velocity, hot–spot temperature, MIITs, RRRCu, inductance, splice resistance, current leads) was performed in the scope of this work. The quench measurements on the Super–FRS dipole prototype were received from the FAIR China Group. The results of calculations performed with the GSI software are either in good agreement with the measurement data or they represent the worst case scenario, e.g. the calculated hot–spot temperature or quench voltage is higher than measured. The second subject concerns the design challenges of the SIS100 quench detection system. An outstanding cycling rate of the dipole circuit (4 T/s), high voltage (U0/U = 1 kV/2 kV), radiation hardness required for the equipment to be installed in the accelerator tunnel (>= 1 MGy) and long signal lines between the magnets and quench detection racks (up to 200 m) implies a customised design of the key components of the system. Selected contributions to the SIS100 quench detection system, concerning the reduction of the parasitic capacitance in the main magnet circuits (by utilising magnetic amplifiers and a new overlapping structure of balance bridges) and the development of a quench detector dedicated to corrector magnets (mutual inductance detector) are presented. |
