A Panel Prototype for the Mu2e Straw Tube Tracker at Fermilab

TL;DR

This paper presents the design, assembly, and prototype of a Mu2e straw tracker panel, crucial for precise electron momentum measurement in the Mu2e experiment at Fermilab.

Contribution

It introduces a novel prototype and assembly method for Mu2e tracker panels, enhancing the detector's precision and reliability.

Findings

Successful prototype assembly demonstrated feasibility

Achieved precise alignment of straw modules

Validated design for low-mass, vacuum-compatible tracker

Abstract

The Mu2e experiment will search for coherent, neutrino-less conversion of muons into electrons in the Coulomb field of an aluminum nucleus with a sensitivity of four orders of magnitude better than previous experiments. The signature of this process is an electron with energy nearly equal to the muon mass. Mu2e relies on a precision (0.1%) measurement of the outgoing electron momentum to separate signal from background. In order to achieve this goal, Mu2e has chosen a very low-mass straw tracker, made of 20,736 5 mm diameter thin-walled (15 $\mu$m) Mylar straws, held under tension to avoid the need for supports within the active volume, and arranged in an approximately 3 m long by 0.7 m radius cylinder, operated in vacuum and a 1 T magnetic field. Groups of 96 straws are assembled into modules, called panels. We present the prototype and the assembly procedure for a Mu2e tracker panel built at Fermilab