Jun 26 – 29, 2017
Schloss Waldthausen
Europe/Berlin timezone

A Cylindrical GEM Inner Tracker for the BESIII Experiment at IHEP

Jun 27, 2017, 6:30 PM
1h 30m
Helmholtz-Institut Mainz

Helmholtz-Institut Mainz

Staudingerweg 18, 55128 Mainz
Board: 30


Marco Maggiora (INFN Torino)


The Beijing Electron Spectrometer III (BESIII) is a multi-purpose detector collecting data provided by the collisions in the Beijing Electron Positron Collider II (BEPCII), hosted at the Institute of High Energy Physics of Beijing. BESIII has already collected the world's largest sample of $J/\psi$ and $\psi(2s)$. Due to the unprecedented luminosity of the BEPCII, the most inner part of the Multilayer Drift Chamber (MDC) is showing aging effects. A new Inner Tracker is being built, based on the new technology of Cylindrical Gas Electron Multipliers (CGEM). The CGEM-IT project is deploying several new features and innovations with respect to the other state-of-art GEM detector: the $\mu$-TPC and analog readout, exploiting both time and charge measurements, allow to reach a 130 µm spatial resolution in the 1 Tesla magnetic field of the BESIII experimental scenario; the support of anodes and cathodes is now composed of Rohacell, a PMI foam with a very low impact on material budget; a new “jagged” design of the anode allows for the reduction of the inter-strip capacitance. The poster provides an update on the status of the project, with a particular focus on the experimental data collected by planar and cylindrical prototypes with cosmic rays and test beams data. These results are beyond the state of the art for GEM technology in such an intense magnetic field. The CGEM-IT project has been founded by the European Commission in the action H2020-RISE-MSCA-2014.

Presentation materials