Challenges and Optimization of Mu2e Proton Target Design with Radiative Cooling

Abstract

The Mu2e experiment at Fermilab will search for the charged lepton flavour violating process of coherent neutrinoless muon-to-electron conversion in the presence of an aluminum nucleus. The muons are produced by an 8 GeV proton beam from the Fermilab Booster striking a production target to create hadrons that decay to muons. The production target design space is strongly constrained by a required one-year operating lifetime and the need for radiative cooling in a vacuum. Uncertainties in the lifetime of the existing baseline design - a monolithic, segmented tungsten (WL10) target - are large, particularly due to unknown effects of radiation damage at the very high proton fluences expected in the experiment. We have begun evaluating a new design utilizing Inconel 718. Here, we present an engineering analysis of a prototype modular design. specifically thermal management, structural stability, fatigue lifetime, and fabrication changes. The results approve a promising new target design for the Mu2e experiment.