Professor Tony Weidberg

Abstract:

Two kinds of photodiodes have been investigated for the ATLAS SCT readout. We present in this paper the results of irradiating bulk and epitaxial Si PIN diodes with 1 MeV-equivalent neutrons and 24 GeV protons. The devices were biased during some of the tests. They were exposed to a fluence of around 2.5×1014 n cm-2 followed by a fluence of approximately 2.5×1014 p cm-2.

Abstract:

A full study of the optical readout package for the ATLAS SCT/Pixel detector data transmission is presented. Radiation hardness studies of VCSEL emitters, Epitaxial Silicon PIN diodes receivers and their associated chips have been carried out with fluences higher than 10(15)n.cm(-2) 1 MeV neutron equivalent and total ionising doses of 10 Mrad. The reliability was assessed by testing a large number of devices and accelerated ageing tests were also pursued over a period equivalent to more than the LHC operation time. Single Event Upset and magnetic field studies up to 6T have also been done on a new optical package design with positive results.

Abstract:

An optical data transmission system based on LED/fibre/PIN diodes is described. This system is suitable for the read out of data from the ATLAS SemiConductor Tracker (SCT). The elements of the system are described and results are given for the performance of a complete chain. The system will be used for beam tests of SCT detector modules. Adaptations of the prototype planned for the production system are discussed.

Abstract:

Many different configurations of electronics and semiconductor strip detectors were studied in 1995 using the ATLAS tracking detector test area at the H8 beam-line of the CERN SPS. A significant fraction of these investigations are presented elsewhere in this volume and this paper will concentrate on the results with silicon strip detectors read out with electronics preserving the pulse height information. Data has been collected with the ADAM, APV5 and FElix read-out chips on a number of different detectors. The first results are presented for read out with LHC electronics of detectors to the ATLAS-A specification of 112.5 μm pitch, employing n-strips in n-type silicon, capacitive coupling and intermediate strips. It is demonstrated that with adequate signal/noise, a spatial resolution of ≃13 μm is attainable with these detectors.