Measurements of ion mobility in argon and neon based gas mixtures

Abstract

As gaseous detectors are operated at high rates of primary ionisation, ions created in the detector have a considerable impact on the performance of the detector. The upgraded ALICE Time Projection Chamber (TPC) will operate during LHC Run$3$ with a substantial space charge density of positive ions in the drift volume. In order to properly simulate such space charges, knowledge of the ion mobility $K$ is necessary. To this end, a small gaseous detector was constructed and the ion mobility of various gas mixtures was measured. To validate the corresponding signal analysis, simulations were performed. Results are shown for several argon and neon based mixtures with different ${\text{CO}}_2$ fractions. A decrease of $K$ was measured for increasing water content.

3 pages, 2 figures

Cited by in corpus (6)

• ALICE upgrades during the LHC Long Shutdown 2
• The upgrade of the ALICE TPC with GEMs and continuous readout
• Ion mobility measurements in Ar-CO${}_2$, Ne-CO${}_2$, and Ne-CO${}_2$-N${}_2$ mixtures, and the effect of water contents
• Ion backflow studies with a triple-GEM stack with increasing hole pitch
• Discharge and stability studies for the new readout chambers of the upgraded ALICE TPC
• Reduction of ion back flow using a quadruple GEM detector with various gas mixtures