Hadron Calorimeter for ATLAS
Design, Construction and Tests of Modules for the End-cap Hadron Calorimeter of Atlas Facility.
Tech Area / Field
- PHY-PFA/Particles, Fields and Accelerator Physics/Physics
8 Project completed
Senior Project Manager
Bunyatov K S
Institute for High Energy Physics (IHEP), Russia, Moscow reg., Protvino
- NPO Molniya, Russia, Moscow
- CERN, Switzerland, Geneva\nMax-Planck-Institut für Physik, Germany, Munich
Project summaryIn December 1994 a new project in the field of High Energy Physics was adopted by the European Nuclear Research Centre (CERN) to construct at the beginning of the next century the most powerful proton-proton collider (LHC) with an energy of 10 TeV. In parallel experimental facilities will also be constructed. Among them is ATLAS - a new generation experimental facility. The purpose of its experimental program is to answer a fundamental scientific question: What is the origin of the different elementary particle masses? More than 1500 scientists and engineers from 32 countries participate in ATLAS collaboration, including Russia, USA, Japan and many European countries.
One of the main detectors of ATLAS is the Hadron Endcap Calorimeter (НЕС), desiMgiierl f.o measure energies of liadron showers. There are two identical endcap calorimeters mi ATLAS installed symmetrically on the right and left with respect to the beam intersection region. The system ol electrodesabsorbers is most complicated part of НЕС. It consists of copper absorbing plates interleaved with high-voltage signal electrodes. Absorbers and electrodes are assembled into modules, modules are united into "wheels". Each "wheel" has 32 modules, each НЕС has 2 "wheels". Forward "wheel" consists of 24 layers of absorber-electrode, backward one of 32. The weight of "wheels" is 66 and 85 tons respectively, external diameter of the "wheels'1 is 4000 mm. In spite of the large diameter and weight ol the ''wheel", all dimensions must be held within an accuracy of 20-30 microns in order to insure the detector characteristics incorporated in the design. The assembled modules undergo mechanical, electric and cryogenic tests to make sure that then1 parameters and characteristics are consistent with the project design. Some of the modules (5 4- 10 %) must be tested in particle beams to measure physical characteristics. It is expected that other modules, due to precise production, will have identical parameters.
By agreement accepted by the ATLAS collaboration, one НЕС is to be produced in Europe (Russia and Germany), the other in America (USA and Canada). The Institute for High Energy Physics (IHEP) is responsible for the production of the copper absorber plates for one "wheel", the assembly of modules, and their mechanical, electrical and cryogenic tests. Electronics, connectors and cables for НЕС are to be supplied by the MP1 (Munich, Germany). Tests of the modules in particle beams and the assembly of modules into "wheels" are shared by all participating teams.
The goal of our proposal includes the following items: simulation and design of the НЕС modules; design of the platform and devices for modules assembly; production of module components, assembly devices and platform; modules assembly; production of equipment to test the modules; study of module characteristics in particle beams; control assembly of modules into a "wheel".
Finally the essential part of one of the most important ATLAS detectors will be completed.
IHEP has successful experience in design, construction and operation of modern setups for experiments in High Energy Physics: Tagged Neutrino Facility at IHEP, DELPHI at CERN LEP-collider. and DO at Fermilab Tevatron.
The staff of the "Molniya" plant will take an active part in all stages starting from simulations and design and ending with tests and studies with particle beams. "Molniya" will develop the technological process of high accuracy and surface-finish handling of large-size copper components in automatic mode using computer controlled machines.
Participating in this Proposal, a large number of engineers and scientists experienced in the field of nuclear weapons will obtain a unique opportunity to use their scientific and technical expertise in solving the tasks of modern fundamental science. Successful realization of this Proposal will open a possibility of wide and long-term participation of the highly qualified staff of "Molniya" in the creation of large-scale experimental facilities for LHC and other accelerators and colliders.
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