Kick sensitivity analysis for the LHC inflectors

The injection kicker system of CERN´s Large Hadron Collider (LHC) will consist of two sets of four kicker magnet systems each producing a magnetic field pulse of 1.3 T.m. with a duration of 6.5 μs, a rise time of 900 ns, and flat top ripple of less than ±0.5%. The electrical circuit of the complete system, including all known parasitic quantities, has been simulated with PSpice. Many parasitic elements were determined from Opera2D simulations which included eddy-currents. Equivalent circuits which simulate the frequency dependence of inductance and resistance of the Pulse Forming Network (PFN) have been derived. PSpice has been utilised to carry out a sensitivity analysis of the field to the value of both individual and groups of circuit components. Capacitors for a prototype 5 Ω PFN have been purchased and, based on the measured values of these capacitors, the diameter of the PFN coil has been re-optimised. The results of the sensitivity analysis have been used to define component tolerances for a prototype PFN. Low and high voltage measurements have commenced on the prototype PFN, and the results of the sensitivity analysis will be used to determine the source of any excessive ripple. This paper presents the results of both the analyses and measurements