No Arabic abstract
The hadron energy resolution of a highly granular CALICE analogue scintillator-steel hadronic calorimeter was studied using pion test beam data. The stochastic term contribution to the energy resolution was estimated to be 58%/sqrt(E/GeV). To improve an energy resolution, local and global software compensation techniques were developed which exploit an unprecedented granularity of the calorimeter and are based on event-by-event analysis of the energy density spectra. The application of either local or global software compensation technique results in reducing of stochastic term contribution down to 45%/sqrt(E/GeV). The achieved improvement of single particle energy resolution for pions is about 20% in the energy range from 10 to 80 GeV.
The energy resolution of a highly granular 1 m3 analogue scintillator-steel hadronic calorimeter is studied using charged pions with energies from 10 GeV to 80 GeV at the CERN SPS. The energy resolution for single hadrons is determined to be approximately 58%/sqrt(E/GeV}. This resolution is improved to approximately 45%/sqrt(E/GeV) with software compensation techniques. These techniques take advantage of the event-by-event information about the substructure of hadronic showers which is provided by the imaging capabilities of the calorimeter. The energy reconstruction is improved either with corrections based on the local energy density or by applying a single correction factor to the event energy sum derived from a global measure of the shower energy density. The application of the compensation algorithms to Geant4 simulations yield resolution improvements comparable to those observed for real data.
The CALICE analog HCAL is a highly granular calorimeter, proposed for the International Linear Collider. It is based on scintillator tiles, read out by silicon photomultipliers (SiPMs). The effects of gaps between the calorimeter tiles, as well as the non-uniform response of the tiles, in view of the impact on the energy resolution, are studied in Monte Carlo events. It is shown that these type of effects do not have a significant influence on the measurement of hadron showers.
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.
Showers produced by positive hadrons in the highly granular CALICE scintillator-steel analogue hadron calorimeter were studied. The experimental data were collected at CERN and FNAL for single particles with initial momenta from 10 to 80 GeV/c. The calorimeter response and resolution and spatial characteristics of shower development for proton- and pion-induced showers for test beam data and simulations using Geant4 version 9.6 are compared.
The CALICE collaboration is developing calorimeters for a future linear collider, and has collected a large amount of physics data during test beam efforts. For the analysis of these data, standard software available for linear collider detector studies is applied. This software provides reconstruction of raw data, simulation, digitization and data management, which is based on grid tools. The data format for analysis is compatible with the general linear collider software. Moreover, existing frameworks such as Marlin are employed for the CALICE software needs. The structure and features of the software framework are reported here as well as results from the application of this software to test beam data.