A highly granular SiPM-on-tile calorimeter prototype

Abstract

The Analogue Hadron Calorimeter (AHCAL) developed by the CALICE collaboration is a scalable engineering prototype for a Linear Collider detector. It is a sampling calorimeter of steel absorber plates and plastic scintillator tiles read out by silicon photomultipliers (SiPMs) as active material (SiPM-on-tile). The front-end chips are integrated into the active layers of the calorimeter and are designed for minimizing power consumption by rapidly cycling the power according to the beam structure of a linear accelerator. 38 layers of the sampling structure are equipped with cassettes containing 576 single channels each, arranged on readout boards and grouped according to the 36 channel readout chips. The prototype has been assembled using techniques suitable for mass production, such as injection-moulding and semi-automatic wrapping of scintillator tiles, assembly of scintillators on electronics using pickand-place machines and mass testing of detector elements. The calorimeter was commissioned at DESY and was taking data at the CERN SPS at the time of the conference. The contribution discusses the construction, commissioning and first test beam results of the CALICE AHCAL engineering prototype.

Silicon photomultipliers in particle and nuclear physics

“…The advent of SiPMs in packages suitable for automatic surface mounting, combined with improvements in device-todevice uniformity and reliability has substantially simplified the construction of active elements for imaging calorimeters. The technical prototype of the CALICE AHCAL [32] makes full use of these possibilities. With fully embedded electronics, SMDstyle photon sensors and plastic scintillator tiles optimized for direct coupling [33], the active elements of the detector can be assembled almost fully automatically, and with a degree of response uniformity perfectly sufficient for hadron calorimetry.…”

“…Figure 8 shows a close-up of this tile-on SiPM design. The high reliability and uniformity of the latest generation of SiPMs allows to do spot testing of bare SiPMs only prior to assembly, rather than A full hadronic calorimeter prototype with a volume of approximately 1 m 3 and 22,000 SiPMs has been constructed based on this design [32], making use of automatized testing and assembly techniques. In May 2018, the detector was first exposed to high-energy particles at the CERN SPS, with just 8 dead channels (0.04%), underlining the quality of present-day SiPMs as well as the robustness of the automated assembly techniques.…”

“…The bare scintillator tile is shown for illustration, in the fully assembled detector all scintillator tiles are wrapped in reflective foil and glued onto the PCB. Figure taken from[32].…”

Toward Realistic Implementations of Large Imaging Calorimeters

“…The analog hadronic calorimeter (AHCAL) [6] consists of 39 successive layers of a 17 mm thick steel absorber and a 3 mm thick scintillator as active material. The active material is segmented in 3×3 cm 2 tiles to achieve high granularity.…”

Study on Granularity Optimization for ILD Hadron Calorimeter

“…The Analogue Hadron CALorimeter (AHCAL) developed in the framework of the CALICE collaboration [1] is a sampling hadronic calorimeter concept based on steel absorber and scintillator tiles (30×30×3 mm 3 ) readout by MPPC (1.3×1.3 mm 2 ) as active materials. The total number of readout channels in full 48 layers is around 8 million.…”