Challenges and Optimization of Mu2e Proton Target Design with Radiative Cooling

TL;DR

This paper analyzes and optimizes the Mu2e proton target design, focusing on radiative cooling and structural stability, proposing a new Inconel 718-based modular target to improve lifetime and performance.

Contribution

It introduces a new Inconel 718 modular target design and provides an engineering analysis addressing thermal, structural, and fabrication aspects for Mu2e.

Findings

Inconel 718 target shows promising thermal and structural performance.

The modular design potentially extends target lifetime.

Engineering analysis supports feasibility of the new design.

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.