The integration and engineering of the ATLAS SemiConductor Tracker Barrel

Abstract

The ATLAS SemiConductor Tracker (SCT) was built in three sections: a barrel and two end-caps. This paper describes the design, construction and final integration of the barrel section. The barrel is constructed around four nested cylinders that provide a stable and accurate support structure for the 2112 silicon modules and their associated services. The emphasis of this paper is directed at the aspects of engineering design that turned a concept into a fully-functioning detector, as well as the integration and testing of large sub-sections of the final SCT barrel detector. The paper follows the chronology of the construction. The main steps of the assembly are described with the results of intermediate tests. The barrel service components were developed and fabricated in parallel so that a flow of detector modules, cooling loops, opto-harnesses and Frequency-Scanning-Interferometry (FSI) alignment structures could be assembled onto the four cylinders. Once finished, each cylinder was conveyed to the next site for the mounting of modules to form a complete single barrel. Extensive electrical and thermal function tests were carried out on the completed single barrels. In the next stage, the four single barrels and thermal enclosures were combined into the complete SCT barrel detector so that it could be integrated with the Transition Radiation Tracker (TRT) barrel to form the central part of the ATLAS inner detector. Finally, the completed SCT barrel was tested together with the TRT barrel in noise tests and using cosmic rays. KEYWORDS: Particle tracking detectors; Solid state detectors; Detector design and construction technologies and materials; Large detector systems for particle and astroparticle physics.

Instrumentation at the LHC—The silicon tracking systems

“…The ATLAS pixel detector [5][6][7][8][9][10][11][12][13][14][15][16][17][18] consists of three barrel layers (1456 modules) and of three end cap discs (288 modules) on each side. The innermost pixel layer is placed at a radius of 50.5 mm from the beam axis.…”

“…Surrounding the pixel detector is the ATLAS SCT [7] consisting of four barrel layers (2112 modules) and nine end cap discs on both sides (1976 modules). The SCT has a radial coverage of 30 cm o r o52 cm, and extends up to 9Z9 ¼ 2:5 in pseudorapidity.…”

ATLAS IBL: a challenging first step for ATLAS upgrade at the sLHC

“…After the successful commissioning and operation, it is planned to extend the LHC physics program by increasing about five times the luminosity in the so-called High-Luminosity LHC (HL-LHC) with a target of an integrated luminosity of 3000 fb -1 . The upgrades for the ATLAS Inner Detector (ID), which consists of a Pixel Detector [2], a Silicon micro-strip tracker (SCT) [3] and a gas-based transition radiation tracker (TRT) [4], are staged in view of the HL-LHC.…”

Development of low-mass, high-density, hybrid for the silicon microstrip sensors in high track density environment

“…Thus, the density of readout chips is quite high, 20 chips on a hybrid in this application. We designed and fabricated a new hybrid, applying a technology of copper-polyimide (Cu/PI) flexible circuit board and carbon-carbon reinforcing material which have been developed and adopted for the present LHC ATLAS silicon strip detector (SCT [2]). This report is focused on the electrical performance of the hybrid.…”