Sigraflex® Studies for LHC CERN Beam Dump: Summary and Perspective

The Large Hadron Collider (LHC) beam dump (TDE) is essential for safe and reliable operation of the collider. It absorbs particles extracted from the accelerator whenever required. The original design of the TDE dates from the mid 2000 and it is constituted of an eight-meter-long cylindrical stainless-steel tube, filled with low-Z carbon-based materials from different grades and densities. The Sigraflex®, an expanded low-density graphite, is employed in the middle section of the TDE core. Due to unexpected behaviour observed in the past LHC runs, several major upgrades were recently implemented in order for the TDE to be ready for LHC Run3 (2021-2024), where up to 555 MJ beam energy is expected to be dumped every few hours. According simulations, temperatures in the Sigraflex core will reach locally up to 1500°C in the regular dump cases, and above 2300°C for failure scenarios. The objective of this contribution is to summarize the LS2 hardware upgrades and the plan for the evaluation of the Sigraflex performance during LHC Run3. This work will also detail the last experimental and numerical findings applied to the Sigraflex®, and possible alternative materials for the future.