[en] The sigma delta (ΣΔ) principle is an analog-to-digital conversion technique based on high-frequency sampling and low-pass filtering of the quantization noise. Resolution in time is exchanged for that in amplitude so as to avoid the difficulty of implementing complex precision analog circuits, in favour of digital circuits. The approach is attractive because it will make it possible to integrate complete channels of high resolution analog-to-digital converters and time digitizers in submicron digital VLSI technologies. Advantage is taken of the fact that the state-of-the-art VLSI is better suited for providing fast digital circuits than for providing precise analog circuits. This article describes the principle and the performance of the ideal ΣΔ digitizer. The design and measurements of a new 10 MHz prototype circuit of a second-order ΣΔ is presented to show the high speed operation of such a circuit. The expected performance of a CMOS test design using the same principles is discussed. Digital filters, useful for particle physics, are introduced. A comparison to other digitizing techniques is made and the potential applications of the ΣΔ digitizer in particle physics are outlined. (orig.)

[en] This paper describes the issues encountered in the design of a large dynamic range digitizer for calorimetry. A gain switching technology developed for the liquid krypton calorimeter of the NA48 CP-violation experiment at CERN is described in detail. 14 bit dynamic range and better than 300 ps time resolution were achieved in beam tests with an 8 channel prototype. A mixed analog/digital ASIC has been developed. A 13,500 channel system is being produced which will be put into operation in 1996

[en] The I/O channels of the control system of the LHC experiments are distributed over the whole detector volume with distances of up to 100 meters. Special requirements on the I/O system arise due to the inaccessibility of the equipment and the hostile environment due to radiation and magnetic field. A general purpose I/O system based on the fieldbus CAN and using the CANopen software protocol has been developed using standard electronic components. Each of these distributed fieldbus nodes can monitor and control up to some hundred channels. The performance of a low-cost high precision ADC system will be presented together with the results of extensive tests

[en] The electronics system for the readout of a large drift chamber (25 m³, 6110 sense wires) with image readout, to be used at the CERN p-anti p collider, is described. The system uses a flash analog-to-digital converter and is able to measure directly the drift time, the charge division, and the energy losses for many tracks on each wire. The results obtained with chamber and electronics prototypes are reported. (orig.)

[en] The ATLAS experiment is one of the experiments at the Large Hadron Collider, constructed to study elementary particle interactions in collisions of high-energy proton beams. The individual detector components as well as the common experimental infrastructure are supervised by the Detector Control System (DCS). The DCS enables equipment supervision using operator commands, reads, processes and archives the operational parameters of the detector, allows for error recognition and handling, manages the communication with external control systems, and provides a synchronization mechanism with the physics data acquisition system. Given the enormous size and complexity of ATLAS, special emphasis was put on the use of standardized hardware and software components enabling efficient development and long-term maintainability of the DCS over the lifetime of the experiment. Currently, the DCS is being used successfully during the experiment commissioning phase

[en] A study of the dynamics of the rare decay K^±→π^±γγ has been performed on a sample of 232 decay candidates, with an estimated background of 17.4±1.1 events, collected by the NA62 experiment at CERN in 2007. The results are combined with those from a measurement conducted by the NA48/2 Collaboration at CERN. The combined model-independent branching ratio in the kinematic range z=(m_γγ/m_K)²>0.2 is B_MI(z>0.2)=(0.965±0.063)×10⁻⁶, and the combined branching ratio in the full kinematic range assuming a Chiral Perturbation Theory description is B(K_πγγ)=(1.003±0.056)×10⁻⁶. A detailed comparison of the results with the previous measurements is performed

[en] The 13500 channels of the NA48 liquid-krypton electromagnetic calorimeter readout electronics were put into operation in 1997. The digitizer electronics employs a new gain switching technique that expands the dynamic range of a standard 10-bit ADC to 14 bits at 40 MHz sampling rate employing a custom-developed integrated circuit (KRYPTON). The KRYPTON has been fabricated in 1.2 μm BiCMOS technology and was successfully developed together with industry on a short timescale. The performance and the experience from the first year of the operation of the liquid-krypton calorimeter electronics will also be briefly discussed. (author)

No abstract available

[en] A precision measurement of the ratio R_K of the rates of kaon leptonic decays K^±→e^±ν and K^±→μ^±ν with the full data sample collected by the NA62 experiment at CERN in 2007–2008 is reported. The result, obtained by analysing ∼150000 reconstructed K^±→e^±ν candidates with 11% background contamination, is R_K=(2.488±0.010)×10⁻⁵, in agreement with the Standard Model expectation

[en] A precision test of lepton flavour universality has been performed by measuring the ratio R_K of kaon leptonic decay rates K⁺→e⁺ν and K⁺→μ⁺ν in a sample of 59 813 reconstructed K⁺→e⁺ν candidates with (8.71±0.24)% background contamination. The result R_K=(2.487±0.013)x10^-5 is in agreement with the Standard Model expectation.