MWPC prototyping and performance test for the STAR inner TPC upgrade

TL;DR

This paper reports on the development and testing of a new MWPC prototype for the STAR inner TPC upgrade, demonstrating it meets all performance specifications through X-ray testing.

Contribution

The paper introduces a new MWPC prototype with improved wire tension and pitch precision, and verifies its performance for the STAR iTPC upgrade.

Findings

Wire tension precision better than 6%

Gas gain uniformity better than 1% RMS

Energy resolution better than 20% FWHM

Abstract

A new prototype of STAR inner Time Projection Chamber (iTPC) MWPC sector has been fabricated and tested in an X-ray test system. The wire chamber built at Shandong University has a wire tension precision better than 6$\%$ and wire pitch precision better than 10 $\mu$m. The gas gain uniformity and energy resolution are measured to be better than 1$\%$ (RMS) and 20$\%$ (FWHM), respectively, using an $^{55}$Fe X-ray source. The iTPC upgrade project is to replace all 24 STAR TPC inner sectors as a crucial detector upgrade for the RHIC beam energy scan phase II program. The test results show that the constructed iTPC prototype meets all project requirements.