Performance study for the photon measurements of the upgraded LHCf calorimeters with Gd₂SiO₅(GSO) scintillators

Abstract

The Large Hadron Collider forward (LHCf) experiment was motivated to understand the hadronic interaction processes relevant to cosmic-ray air shower development. We have developed radiation-hard detectors with the use of Gd2SiO5 (GSO) scintillators for proton-proton √s = 13 TeV collisions. Calibration of such detectors for photon measurement has been completed at the CERN SPS T2-H4 line in 2015 using electron beams of 100–250 GeV and muon beams of 150–250 GeV . After the channel-by-channel absolute energy calibration, the energy resolution of the calorimeters is confirmed to be better than 3% for electrons with energy above 100 GeV . The position dependence of the energy scale of the calorimeters was reduced to the level of 1% after the corrections for scintillator nonuniformity and the shower leakage effect. The position resolution of the new shower imaging detector, a GSO-bar hodoscope interleaved in the calorimeter, was 100 μm for 200 GeV electrons. The experimental results are well explained by Monte Carlo simulations. We have confirmed that the new detectors meet the requirement of the LHCf experiment at √s = 13 TeV.

The Performance of the New LHCf Detector for Hadronic Showers

“…To correct these effects, we computed correction factors. In the simulation, we included the light collection maps [2] and injected 1 TeV neutron beam to whole the detector. The shower leakage correction factor by,…”

“…Due to the upgrade, we confirmed the performance of the LHCf detectors using accelerator beams and Monte Carlo simulations. We already completed the performance study for electro-magnetic showers [2]. In this paper, we report the performance of the LHCf detectors for hadronic showers.…”

A Brief Discussion on the Performance of the MoEDAL and the LHCf Experiments

“…The leakage from the EM shower is really negligible at the back of the tower. The schematic diagrams of each of the towers are shown in Figure 5 [11].…”

Measurement of very forward particle production at RHIC with √s=510 GeV proton-proton collisions

“…Array of thin scintillator bars read by a MAPMT consists a position sensitive layer and 4 X-Y pairs of such array is inserted in each calorimeter [13]. Detail of the detector [8] and its performance measured at the CERN SPS fixed target experiment facility [14] [15] and during the LHC operation in 2009-2010 [16] are found elsewhere. Because the RHIC beam energy, 255 GeV, coincides with the beam energy at SPS, calibration at SPS is directly applicable for the RHICf operation.…”

“…The Relativistic Heavy Ion Collider forward (RHICf) experiment has measured neutral particles produced in the very forward direction in the √ s=510 GeV proton-proton collisions at RHIC in June 2017. The production cross sections of these particles are crucial to understand the hadronic interaction relevant to the air shower development at the cosmic-ray equivalent energy of 1.4×10 14 eV, just below the energy of the knee. Together with the data at LHC, accelerator data can cover the interaction in the cosmic-ray energy of 10 14 eV to 10 17 eV.…”