Ian Kenyon

Irradiation studies of multimode optical fibres for use in ATLAS front end links

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 neutro ...

System tests of radiation hard optical links for the ATLAS semiconductor tracker

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 radiat ...

The H1 forward muon spectrometer

Abstract The H1 detector started taking data at the electron-proton collider HERA in the beginning of 1992. In HERA 30 GeV electrons collide with 820 GeV protons giving a strong boost of the centre-of-mass system in the direction of the proton, also called the forward region. For the detection of high momentum muons in this region a muon spectrometer has been constructed, consisting of six drift chamber planes, three either side of a toroidal magnet. A first brief description of the system and its main parameters as well as the principles for track reconstruction and T 0 determination is given.

ATLAS beam test results

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.

Lightwave Analogue Links For LHC Detector Front-ends

The requirements on optical links for transferring analog and digital signals from the detector front-ends to the readout electronics at future high-luminosity colliders are reviewed. The advantages of external modulation techniques are discussed. An outline is given of the the R&D programme recently started at CERN by a collaboration involving high-energy physics institutes, optoelectronics research laboratories and industry, in order to develop electro-optic intensity modulator arrays, particularly for analogue applications, and to investigate the feasibility of volume production. The design of multichannel demonstrators in lithium niobate and III-V semiconductor technology is described. Preliminary results of the performance measurements are presented.

HIPPI developments for CERN experiments

Attention is given to the High-Performance Parallel Interface (HIPPI), a new ANSI standard, using a minimal protocol and providing 100-Mbyte/s transfers over distances up to 25 m. Equipment using this standard is offered by a growing number of computer manufacturers. A commercially available HIPPI chipset allows low-cost implementations. A brief technical introduction to the HIPPI is given, followed by examples of planned applications in high-energy physics experiments, including the developments involving CERN: a detector emulator, a RISC, (reduced instruction set computer) processor based VMEconnection, a long-distance fiber-optics connection, and a HIPPI testbox.<<ETX>>

The UA1 upgrade calorimeter trigger processor

Abstract The increased luminosity of the improved CERN Collider and the more subtle signals of second-generation collider physics demand increasingly sophisticated triggering. We have built a new first-levl trigger processor designed to use the excellent granularity of the UA1 upgrade calorimeter. This device is entirely digital and handles events in 1.5 μs, thus introducing no dead time. Its most novel feature is fast two-dimensional electromagnetic cluster-finding with the possibility of demanding an isolated shower of limited penetration. The processor allows multiple combinations of triggers on electromagnetic shower, hadronic jets and energy sums, including a total-energy veto of multiple interactions and a full vector sum of missing transverse energy. This hard-wired processor is about five times more powerful than its predecess or, and makes extensive use of pipelining techniques. It was used extensively in the 1988 and 1989 runs of the CERN Collider.

UA1 upgrade first-level calorimeter trigger processor

Abstract A new first-level trigger processor has been built for the UA1 experiment on the Cern SppS Collider. The processor exploits the fine granularity of the new UA1 uranium-TMP calorimeter to improve the selectivity of the trigger. The new electron trigger has improved hadron jet rejection, achieved by requiring low energy deposition around the electromagnetic cluster. A missing transverse energy trigger and a total energy trigger have also been implemented.

Evaluation of LiNbO3 optical amplitude modulators for use in analogue electro-optic readout links from HEP particle detectors

Abstract The use of lithium niobate optical intensity modulators for reading out analogue data from HEP particle detector elements has been evaluated. Two such devices designed for operation in the 1300 nm telecoms band have been tested with several different laser light sources. A systematic study has been undertaken to quantify possible noise sources in the optical link and their impact on the overall operation of the link. A dynamic range of ∼ 200:1 has been measured for a maximum nonlinearity of 1% and a minimum peak signal to rms noise ratio of 3:1, with the modulator biased at its quadrature point.