First beam tests of prototype silicon modules for the CMS High Granularity Endcap Calorimeter

Abstract

The High Luminosity phase of the Large Hadron Collider will deliver 10 times more integrated luminosity than the existing collider, posing significant challenges for radiation tolerance and event pileup on detectors, especially for forward calorimetry. As part of its upgrade program, the Compact Muon Solenoid collaboration is designing a high-granularity calorimeter (HGCAL) to replace the existing endcap calorimeters. It will feature unprecedented transverse and longitudinal readout and triggering segmentation for both electromagnetic and hadronic sections. The electromagnetic section and a large fraction of the hadronic section will be based on hexagonal silicon sensors of 0.5–1 cm2 cell size, with the remainder of the hadronic section being based on highly-segmented scintillators with silicon photomultiplier readout. The intrinsic high-precision timing capabilities of the silicon sensors will add an extra dimension to event reconstruction, especially in terms of pileup rejection. First hexagonal silicon modules, using the existing Skiroc2 front-end ASIC developed for CALICE, have been tested in beams at Fermilab and CERN in 2016. We present results from these tests, in terms of system stability, calibration with minimum-ionizing particles and resolution (energy, position and timing) for electrons, and the comparisons of these quantities with GEANT4-based simulation.

Beam-tests of CMS High Granularity Calorimeter prototypes at CERN

“…Data were also acquired for 200 GeV/c muons and used for the MIP calibration. The same tracking procedure developped for [2] was applied, showing the capability of the detector to reconstruct tracks. These were also used to calibrate the response of the detector.…”

“…Two beam tests were done in 2016 at CERN and FNAL to validate the design of the CE-E section and to provide the first performance measurements. The results were reported in [2]. In October 2018 the first full HGCAL prototype was assembled and its performance was studied in beam tests at the H2 CERN beamline.…”

“…a central module surrounded by 6 outer modules) and 3 layers equipped with single modules. The Hexaboards followed the same design as of 2016 [2], consisting of a stack of a copper-tungsten baseplate, a polymide foil, a silicon sensor of 300 or 200 µm and a readout PCB. A sketch of this structure is shown in figure 2b.…”

The DAQ system of the 12,000 channel CMS high granularity calorimeter prototype

“…The tests of HGCAL and AHCAL prototypes with particle beams in the H2 area at CERN had been complemented by the readout of various beam-characterization detectors. Four delay wire chambers (DWC) [13] measured the trajectory and impact of the particles in the beam, two scintillator detectors served as external trigger source and two micro-channel plates (MCP) had been used to provide fast signals for reference timing measurement of the incident particles [14]. For this purpose, two 16-channel CAEN v1290N TDCs and one v1742 digitiser were integrated into the HGCAL prototype DAQ.…”

The CMS HGCAL detector for HL-LHC upgrade

“…Beam tests Several beam tests have been performed over the last three years in order to explore the feasibility of the novel detector design of HGCAL as well as to evaluate the physics performance in prototypes [6]. These beam tests also serve to verify and optimize the physics models used for Monte Carlo simulations of this kind of sampling calorimeter with silicon and scintillator active layers.…”