Professor Tony Weidberg

Abstract:

The ATLAS SCT optical links system is reviewed. The assembly and testing of prototype opto-hamesses are described. Results are also given from a system test of the SCT barrel modules, including optical readout.

Abstract:

The radiation tolerance of three multimode optical fibres has been investigated to establish their suitability for the use in the front-end data links of the ATLAS experiment. Both gamma and neutron irradiation studies are reported. A step-index fibre with a pure silica core showed an induced attenuation of approximately 0.05 dB/m at 330 kGy(Si) and 1×1015 n(1 MeV Si)/cm2 and is suitable for use with the inner detector links which operate at 40-80 Mb/s. A graded-index fibre with a predominantly germanium-doped core exhibits an induced attenuation of approximately 0.1 dB/m at 800 Gy(Si) and 2×1013 n(1 MeV Si)/cm2 and is suitable for the calorimeter links which operate at 1.6 Gb/s. Measurements of the dose rate dependence of the induced attenuation indicate that the attenuation in ATLAS will be lower.

Abstract:

A prototype optical data and Timing, Trigger and Control transmission system based on LEDs and PIN-diodes has been constructed. The system would be suitable in terms of radiation hardness and radiation length for use in the ATLAS SemiConductor Tracker. Bit error rate measurements were performed for the data links and for the links distributing the Timing, Trigger and Control data from the counting room to the front-end modules. The effects of cross-talk between the emitters and receivers were investigated. The advantages of using Vertical Cavity Surface Emitting Lasers (VCSELs) instead of LEDs are discussed.

Abstract:

The radiation hard opto-electronic links being developed for the ATLAS Semiconductor Tracker (SCT) and Pixel detectors are described. The results of the radiation tests on all the on-detector components are reviewed. Results of environmental tests of irradiated opto-packages are mentioned. New results on Single Event Upset Studies are presented and the implications for ATLAS operation are discussed.Two versions of the ATLAS SCT style on-detector opto-package are described. The performance of these packages are compared to the ATLAS specifications. These packages have been integrated into the SCT system and extensive system tests have been performed. The experience with the assembly of the first larger scale integration is discussed.