Speakers
Dr
GIULIO MEZZADRI
(INFN Ferrara - IHEP)
Riccardo Farinelli
(INFN - Ferrara)
Description
BESIII (Beijing Spectrometer III) is a multipurpose spectrometer optimized
for physics in the tau-charm energy region. Both detector and accelerator
are undergoing an upgrade program, that will allow BESIII to run until
2029.
A major upgrade is the replacement of the inner drift chamber with a new
detector based on Cylindrical Gas Electron Multipliers to improve both the
secondary vertex reconstruction and the radiation tolerance. The CGEM-IT
will be composed of three concentric layers of cylindrical triple GEMs,
operating in an Ar-ISO (90/10) gas mixture with field and gains optimized
to maximize the spatial resolution using a charge and time readout. The
new detector is readout with innovative TIGER electronics produced in 110
nm CMOS technology. The front end is a custom designed 64-channel ASIC
featuring a fully digital output and operated in triggerless mode. It can
provide analog and time measurements at the same time with a TDC time
resolution better than 100 ps, that will allow to operate the cylindrical
layers in the microTPC mode.
With planar prototypes, we measured an unprecedented spatial resolution
below 150 microns in 1 Tesla magnetic field. It was measured in a wide range
of incident angle of the incoming particle.
Before the installation inside BESIII, foreseen in 2021, a long standalone
data taking is ongoing at the Institute of High Energy Physics in Beijing;
currently, the first two cylindrical chambers are available for the test,
and are used to complete the integration between the detector and the
electronics and to assess the required performance.
In this presentation a description of the CGEM-IT project, the TIGER
features and performance, and the results of the analysis of first cosmic
ray data taking will be presented. Focus will be given on the strip
analysis, from which it is possible to measure the basic properties of the
detector, and the cluster analysis, where a comparison with the results
with planar prototypes will be discussed. The first preliminary results on
efficiency and spatial resolution will be also presented.
Primary author
Dr
GIULIO MEZZADRI
(INFN Ferrara - IHEP)
