Requested modifications to the 13 kA Energy Extraction Facilities and their Implementation. Request for a faster current decay in the Main Dipole and Main Quadrupole Circuits The request is considered for operation at beam energies up to 4 TeV ( ~ 6850 A), at least for the moment
Main Quadrupole Circuits: Facilities and their Implementation
Consists equally of three, parallel-connected units
However, not disconnectable as welded structure.
Consequently, additional series-connected unit needed
Present values: 7.7 m Facilities and their ImplementationΩ / 6.6 mΩ – giving τ = 30 s (incl. cable resistance)
Additional, CERN-made, plate resistor for external series-connection
1.80 mΩ / plate, 4 series-connected plates gives τ = 15 s ( 16.8 mΩ total incl. cable resistance)
Thus dI/dt max = 457 A/s , compared to 310 A/s as commissioned value.
Large margin to quench-back.
Max voltage to ground at 6850 A: 115 V – no problem
Delay opening of one of the two switch assemblies of each dipole circuit in order to attenuate the initial voltage transient
Implementation on each of the eight OOC boards in the two BCM’s of one switch assembly.