CMS physics technical design report : Addendum on high density QCD with heavy ions

Peer reviewe

Thermal design and tests for the CMS HCAL readout box

A method is necessary to cool the electronics contained in the readout boxes for the CMS HCAL. The electronics to pre-amplify and digitize signals from the optical detectors will generate a large amount of heat that must be removed from the CMS HCAL system. To accomplish this a thermal management system has been designed that uses metallic extrusions, liquid coolant, and thermal foam to transfer the heat from the electronics to the exterior cooling system. Because the electronics are difficult to access throughout the life of the experiment, the temperature must be kept low to extend life expectancy. In order to test the concepts before the final design is implemented a thermal test station was built. Several methods to are under study to determine the best method of making the thermal routing from source of the heat to the liquid for heat removal. The test bed for this evaluation and methods to monitor the electronics temperature in situ will be discussed. 3 Refs

Front-end electro-optical interfaces for CMS HCAL

The CMS experiment is a complex instrument to study particle physics at the energy frontier. An important detector subsystem within CMS is the hadron calorimeter or HCAL, consisting of four subsystems that cover the kinematic region $\beta$ <5. This paper provides details of the electro-optical interfaces for the central barrel subsystem that operates in a region of high magnetic field and converts scintillation signals from megatile sampling layers to lower geometry for energy measurement. (3 refs)

The CMS experiment at the CERN LHC

The Compact Muon Solenoid (CMS) detector is described. The detector operates at the Large Hadron Collider (LHC) at CERN. It was conceived to study proton-proton (and lead-lead) collisions at a centre-of-mass energy of 14 TeV (5.5 TeV nucleon-nucleon) and at luminosities up to 10(34)cm(-2)s(-1) (10(27)cm(-2)s(-1)). At the core of the CMS detector sits a high-magnetic-field and large-bore superconducting solenoid surrounding an all-silicon pixel and strip tracker, a lead-tungstate scintillating-crystals electromagnetic calorimeter, and a brass-scintillator sampling hadron calorimeter. The iron yoke of the flux-return is instrumented with four stations of muon detectors covering most of the 4 pi solid angle. Forward sampling calorimeters extend the pseudo-rapidity coverage to high values (vertical bar eta vertical bar <= 5) assuring very good hermeticity. The overall dimensions of the CMS detector are a length of 21.6 m, a diameter of 14.6 m and a total weight of 12500 t

The CMS experiment at the CERN LHC

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CMS physics technical design report: Addendum on high density QCD with heavy ions

This report presents the capabilities of the CMS experiment to explore the rich heavy-ion physics programme offered by the CERN Large Hadron Collider (LHC). The collisions of lead nuclei at energies ,will probe quark and gluon matter at unprecedented values of energy density. The prime goal of this research is to study the fundamental theory of the strong interaction - Quantum Chromodynamics (QCD) - in extreme conditions of temperature, density and parton momentum fraction (low-x). This report covers in detail the potential of CMS to carry out a series of representative Pb-Pb measurements. These include "bulk" observables, (charged hadron multiplicity, low pT inclusive hadron identified spectra and elliptic flow) which provide information on the collective properties of the system, as well as perturbative probes such as quarkonia, heavy-quarks, jets and high pT hadrons which yield "tomographic" information of the hottest and densest phases of the reaction.0info:eu-repo/semantics/publishe