Beam Dumps and Beam Stoppers for LHC and CNGS Transfer Lines

Three new beam transfer lines are presently under construction at the SPS: TI2 and TI8 which will transfer protons and ions to the LHC, and TT41 which will transfer protons to the CNGS neutrino target. Three beam dumps (TED) and two beam stoppers (TBSE) will be installed in TI2 and TI8, and one TBSE in TT41. Both types of equipment are required to intercept the 450 GeV SPS beams concentrated in very short pulses (7.8 µs-10.5 µs) at intensities up to ~ 5 10**13 protons, every 16.8 seconds for the TED and as single shot for the TBSE. The outer TED iron shielding will be identical to the existing SPS one, while dimensions and material composition of both TED and TBSE cores have been optimised to cope with the new beam conditions. The optimised TED inner core consists of a Ø80 mm graphite cylinder 2.9 m long, housed into a Ø80/160 mm aluminium blind tube 3.5 m long, itself fitted into a Ø160/310 mm copper blind tube 4.3 m long. The TBSE is made of the same graphite cylinder, housed into a Ø80/120 mm aluminium blind tube 3.5 m long, itself fitted into a Ø120/240 mm iron blind tube 4 m long. The maximum allowed beam intensity for a safe operation is given as a function of the pulse duration, including slow pulses as presently aborted on SPS dumps. The analytical methods set out in the thermo-mechanical part of this study are of general application, and may help in many other axi-symmetrical beam deposition analyses