Tracking System for "Atlas"
Design and Development of Large Area Precision Tracking Detectors and Their Support Structures (Phase I)
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
- VNIITF, Russia, Chelyabinsk reg., Snezhinsk\nJoint Institute of Nuclear Research, Russia, Moscow reg., Dubna
Project summaryThe principal aim of this proposal is the development and construction of large area (> 400 m2) precision detector units, which will be used for research at the Large Hadron Collider (LHC) at CERN, scheduled to become operational in 2005. Such large area Tracking Detectors recording the position of charged particles or photons with a spatial localisation of 0.1 mm or better are required in fundamental research in elementary particle physics.
The detector structure must be light in order not to absorb or deviate particles. The engineering challenge therefore is to use thin standard metals which, however, when combined must result in solid and precise structures. Finite Element Analysis and 3-D CAD design are mandatory for the engineering optimisation.
We also see interesting commercial and medical applications. Such detector structures offer superior performance for large-scale X-raying (medical diagnosis, materials studies, safety applications).
The technology of large-scale lightweight mechanical supports has potentially other applications: antenna structures in telecommunications and support for mirrors (astronomical telescopes, solar-concentrator applications).
This proposal addresses the development and construction of such instruments, namely the two basic components: the support structures and the detectors which need to be developed and built in a co-ordinated way.
The particle detector is based on a novel concept developed by members of the ATLAS collaboration, including the JINR in Dubna and IHEP Protvino. It uses precision-drawn aluminium tubes, in which a gas-mixture at 3 atm is used as the detection medium and a central wire electrode to collect the ionization. These detection tubes have to be assembled into 'detector units', in which each tube is located with a precision of 0.02 mm. The collaborating groups have developed a concept for this precision assembly and a procedure for mass production. One such detector mass production unit is envisaged at JINR in Dubna and another one at IHEP Protvino. Within the frame of this proposal, it is envisaged to construct a total of 192 detector units, comprising approximately 60,000 detector tubes.
The second component is the large support frame ‘Big Wheel’ (discs of typically 450 m2) on which the detector units are mounted. Within the ISTC programme #544 a design concept was developed, which achieves a lightweight construction together with the required stability. Within the present proposal the collaborating groups plan to build on this conceptual design work and to develop the construction methods for these two components (detector units and support structures). Within the frame of this proposal it is planned to construct a total of eight such ‘Big Wheel’ support structures.
This work plan will be carried out in the following way.
VNIITF is responsible for the complete design of the support frames including Finite Element Analysis and for the preparation of the construction drawings.
VNIITF will also be responsible for the fabrication of the eight support frames.
IHEP Protvino has the main responsibility for the development and implementation of the series production of the detector units. The major mechanical precision components needed for the construction will be purchased from Russian firms.
JINR Dubna has the main responsibility for the development and implementation of the series production of the detector units (drift tubes detectors) for the barrel region of the ATLAS muon spectrometer. It will assemble 36000 detection elements. The procedures for mounting the detector units on the support frames will be developed. It will be also study the production of mounting tools in Russian industry.
CERN will be involved in the systems integration. It will participate in the project organization via the Internet/Web together with the institutes mentioned, in particular concerning schedule and milestone follow up and quality assurance. For this purpose the project management structure and tools (CDD, EDMS), which are in place for the ATLAS project, will be used. It will also act as an interface to Western institutes.
MPI Munich will contribute to the construction of the detection elements at JINR. It will coordinate information of other sites producing detection elements. It will also participate in the project monitoring.