Installation of proANUBIS -- a proof-of-concept demonstrator for the ANUBIS experiment

AN Underground Belayed In-Shaft search experiment (ANUBIS) was proposed to search for neutral long-lived particles (LLPs) at CERN’s ATLAS underground cavern. A prototype or a proof-of-concept demonstrator detector - proANUBIS was recently installed to prove the feasibility of such an experiment. The prototype demonstrator is expected to play a role in validating simulation studies and providing insights into the anticipated backgrounds for the ANUBIS experiment. The current report provides an overview of the experimental setup for this prototype detector, and its commissioning and installation details.