Pion-Production Target for Mu2e-II: Simulation Design and Prototype

This paper discusses our recent advances in conceptual design R&D for a conveyor-type Mu2e-II target station based on energy deposition and radiation damage simulations. Our study involves Monte-Carlo codes as well as thermal and mechanical ANSYS analyses to estimate the stability of the system. The concurrent use of multiple simulation packages is intended to allow us to determine and minimize the systematic uncertainty of the simulations. Our simulations allowed us to rule out some designs (rotated and fixed granular targets) as less practical and supported our assessment of the new target station's required working parameters and constraints. The thermal and mechanical analyses we performed enabled us to determine the choice of cooling scheme and prospective materials for the conveyor's spherical elements. We will discuss the first prototype of the Mu2e-II target and mechanical tests performed at Fermilab that indicated the feasibility of the proposed design and its weaknesses, and we will suggest directions for further improvement.