Construction and commissioning of the CALICE analog hadron calorimeter prototype

Abstract

An analog hadron calorimeter (AHCAL) prototype of 5.3 nuclear interaction lengths thickness has been constructed by members of the CALICE Collaboration. The AHCAL prototype consists of a 38-layer sandwich structure of steel plates and highly-segmented scintillator tiles that are read out by wavelength-shifting fibers coupled to SiPMs. The signal is amplified and shaped with a custom-designed ASIC. A calibration/monitoring system based on LED light was developed to monitor the SiPM gain and to measure the full SiPM response curve in order to correct for non-linearity. Ultimately, the physics goals are the study of hadron shower shapes and testing the concept of particle flow. The technical goal consists of measuring the performance and reliability of 7608 SiPMs. The AHCAL was commissioned in test beams at DESY and CERN. The entire prototype was completed in 2007 and recorded hadron showers, electron showers and muons at different energies and incident angles in test beams at CERN and Fermilab.

The International Linear Collider Technical Design Report - Volume 4: Detectors

“…From the extensive CALICE test beam program, in which the AHCAL physics prototype [314] modules were used from 2006 until 2011, a wealth of results on detector performance, simulation validation and operational experience are available. The long-term operation of the AHCAL physics prototype, together with a large number of assembly and disassembly procedures, often coupled with long-distance shipping of the detector, has provided substantial information of the stability and reliability of the AHCAL technology.…”

“…The long-term operation of the AHCAL physics prototype, together with a large number of assembly and disassembly procedures, often coupled with long-distance shipping of the detector, has provided substantial information of the stability and reliability of the AHCAL technology. The number of observed non-working channels is very moderate at roughly 2%, most of which are due to broken solder points at the connection of the SiPMs to the PCB leading to the front-end electronics that were caused by deformations of the board during detector movements [314].…”

“…The transverse segmentation suggested by simulations is about 3 ◊ 3 cm 2 and leads to a number of read-out channels an order of magnitude smaller than in the digital case with 1 ◊ 1 cm 2 cells. The CALICE AHCAL [314] was the first device that used the novel SiPM technology on a large scale, and its robustness and reliability has encouraged other experiments, e.g. T2K, CMS and Belle, to apply it in their detector upgrades.…”

Track segments in hadronic showers in a highly granular scintillator-steel hadron calorimeter

“…One of these calorimeters is the analog hadron calorimeter (AHCAL) [4], a sampling calorimeter with 38 active layers of plastic scintillator sandwiched between steel absorber plates with lateral dimensions of 90 × 90 cm 2 and a total instrumented volume of approximately 1 m 3 . The scintillator layers consist of 5 mm thick scintillator tiles, each individually read out by a silicon photomultiplier (SiPM) [5,6].…”

Challenges of front-end and triggering electronics for High Granularity Calorimetry

“…For the readout of the SiPMs a version of the HGCROC, including a capacitive charge divider, will be produced. HGCROC is based on the SKIROC2 chip [5] for the CALICE collaboration [6]. A development version named SKIROC2_CMS, optimized for the CMS testbeam, shows encouraging results [7].…”