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In particle physics experiments, the quality of calorimetric particle detection is typically considerably worse for hadrons than for electromagnetic showers. In this paper, we investigate the root causes of this problem and evaluate two different methods that have been exploited to remedy this situation: compensation and dual readout. It turns out that the latter approach is more promising, as evidenced by experimental results. [ABSTRACT FROM AUTHOR]

A compact Time Projection Chamber (TPC) with a gas electron multiplier (GEM) is a good candidate for three-dimensional (3D) beam diagnosis of electron and ion beams. To develop the beam diagnostics, we performed simulation studies to design a compact GEM-TPC with COMSOL and GARFIELD++. The primary purpose of this detector is to measure the 3D beam profile at the medical cancer center, which requires a position resolution of ∼ 300 μ m in each coordinate and can accommodate a proton rate of 104 s−1. For the design of the detector that satisfies the requirements, the simulations were done on the electric field homogeneity of the cylindrical field cage, the transport properties, and the amplification of electrons in the argon-based gases. This paper presents the design parameters of the compact TPC for constructing a high-precision 3D beam diagnostic system derived from COMSOL and GARFIELD++ simulations. • Simulation studies to design a 3D beam diagnostic system with a compact GEM-TPC. • Investigation of electric field homogeneity of the cylindrical field cage by COMSOL. • Studies of transport properties and amplification of electrons in the mixed gases. • Decide the design parameters of the compact GEM-TPC. [ABSTRACT FROM AUTHOR]

Abstract: As the energies at which the elementary structure of matter is studied increased, the emphasis in scattering experiments has shifted from detecting individual hadrons to fragmenting quarks and gluons, which manifest themselves as particle jets. In this paper, we investigate and quantify some systematic effects that affect the precision with which the properties of the fragmenting constituents can be determined. We concentrate on the calorimeters that are used to measure the energies, and in particular on how the non-compensating nature of a calorimeter affects the energy measurement of different types of partons. [Copyright &y& Elsevier]

The RD52 (DREAM) collaboration is performing R&D on dual readout calorimetry techniques with the aim of improving hadronic energy resolution for future high energy physics experiments. The simultaneous detection of Cherenkov and scintillation light enables us to measure the electromagnetic fraction of hadron shower event-by-event. As a result, we could eliminate the main fluctuation which prevented from achieving precision energy measurement for hadrons. We have tested the performance of the lead and copper fiber prototypes calorimeters with various energies of electromagnetic particles and hadrons. During the beam test, we investigated the energy resolutions for electrons and pions as well as the identification of those particles in a longitudinally unsegmented calorimeter. Measurements were also performed on pure and doped PbWO4 crystals, as well as BGO and BSO, with the aim of realizing a crystal based dual readout detector. We will describe our results, focusing on the more promising properties of homogeneous media for the technique. Guidelines for additional developments on crystals will be also given. Finally we discuss the construction techniques that we have used to assemble our prototypes and give an overview of the ones that could be industrialized for the construction of a full hermetic calorimeter. [ABSTRACT FROM AUTHOR]