PoS - Proceedings of Science
Volume 364 - European Physical Society Conference on High Energy Physics (EPS-HEP2019) - Detector R&D and Data Handling
Upgrade of the ALICE Time Projection Chamber for the LHC Run3
A.L. Gera* and  on behlaf of the ALICE TPC collaboration
Full text: pdf
Pre-published on: November 09, 2020
Published on: November 12, 2020
ALICE, one of the experiments at the Large Hadron Collider (CERN), is undergoing ambitious upgrades during the ongoing second long shutdown (LS2). The main goal of this project is to access rare events and previously inaccessible physics observables. The increased Pb–Pb and pp collision rates need a correspondingly higher TPC operation rate in the next Run 3 of the LHC.

The operational gated MWPC readout used so far cannot be used at such fast rates. Therefore a new readout chamber is needed with a novel technology and without any compromise on the momentum and energy resolution. As a solution the Gas Electron Multiplier (GEM) technology is applied. This new readout chamber consists of inner- (IROC) and outer (OROC) readout cham-bers with a 4 stage GEM cascade in order to reduce back-drifting ion space charges. These quad-ruple stacks have proven to provide sufficient ion blocking capabilities. This structure also pre-serves the intrinsic energy resolution and keeps the space-charge distortions at a tolerable level. The GEMs cannot be repaired during operation, therefore to minimize the unsuitable foils, the Quality Assurance system is developed. These cleanroom measurements investigate the hole size uniformity, the gain uniformity and the electrical stability. Due to the continuous readout, higher readout rate is possible. The new ASIC-SAMPA has been developed for this purpose.

After the ROC assembly some of chambers were tested in the ALICE cavern, and a test campaign started for the further testing of the ROC bodies at GIF++ at CERN.
DOI: https://doi.org/10.22323/1.364.0102
How to cite

Metadata are provided both in "article" format (very similar to INSPIRE) as this helps creating very compact bibliographies which can be beneficial to authors and readers, and in "proceeding" format which is more detailed and complete.

Open Access
Creative Commons LicenseCopyright owned by the author(s) under the term of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.