S. Steiner

The H1 silicon vertex detector

Abstract The design, construction and performance of the H1 silicon vertex detector is described. It consists of two cylindrical layers of double-sided, double-metal silicon sensors read out by a custom designed analog pipeline chip. The analog signals are transmitted by optical fibres to a custom-designed ADC board and are reduced on PowerPC processors. Details of the design and construction are given and performance figures from the first data-taking periods are presented.

Performance Verification of the FlashCam Prototype Camera for the Cherenkov Telescope Array

Abstract The Cherenkov Telescope Array (CTA) is a future gamma-ray observatory that is planned to significantly improve upon the sensitivity and precision of the current generation of Cherenkov telescopes. The observatory will consist of several dozens of telescopes with different sizes and equipped with different types of cameras. Of these, the FlashCam camera system is the first to implement a fully digital signal processing chain which allows for a traceable, configurable trigger scheme and flexible signal reconstruction. As of autumn 2016, a prototype FlashCam camera for the medium-sized telescopes of CTA nears completion. First results of the ongoing system tests demonstrate that the signal chain and the readout system surpass CTA requirements. The stability of the system is shown using long-term temperature cycling.

Compact frontend-electronics and bidirectional 3.3 Gbps optical datalink for fast proportional chamber readout

Abstract The 9600 channels of the multi-wire proportional chamber of the H1 experiment at HERA have to be read out within 96 ns and made available to the trigger system. The tight spatial conditions at the rear end flange require a compact bidirectional readout electronics with minimal power consumption and dead material. A solution using 40 identical optical link modules, each transferring the trigger information with a physical rate of 4×832 Mbps via optical fibers, has been developed and commissioned. The analog pulses from the chamber can be monitored and the synchronization to the global HERA clock signal is ensured.

Performance of the LHCb Silicon Tracker in p - p collisions at the LHC

The LHCb detector is designed to study the decays of B-mesons in proton-proton collisions at the Large Hadron Collider (LHC). The detector is a single arm forward spectrometer with excellent tracking and particle identification capabilities. The Silicon Tracker (ST) consists of two detectors both of which are constructed from silicon micro-strip detectors with long readout strips. The performance of these detectors in the first high energy collisions at the LHC is presented here. The data collected in 2010 has been used to determine the optimal time and spatial alignment of the detectors. A detailed study has also been made of the intrinsic detector efficiency and resolution. The latest results on detector performance will be shown and compared to the expectation from previous measurements and the simulation of the detector.The Large Hadron Collider beauty experiment (LHCb) is a single-arm forward spectrometer dedicated to the study of B-meson decays in p - p collisions at the Large Hadron Collider (LHC). The LHCb detector has excellent tracking and particle identification capabilities. The LHCb Silicon Tracker (ST) is composed of two silicon micro-strip detectors with long readout strips. The performance of these two detectors with the first high energy p - p collisions are presented here. A detailed study of the detectors intrinsic resolution and efficiency has been performed along with precise time alignment using collision data. The latest Silicon Tracker performance results and comparison to expectations are presented.

Mechanical design and material budget of the CMS barrel pixel detector

The Compact Muon Solenoid experiment at the Large Hadron Collider at CERN includes a silicon pixel detector as its innermost component. Its main task is the precise reconstruction of charged particles close to the primary interaction vertex. This paper gives an overview of the mechanical requirements and design choices for the barrel pixel detector. The distribution of material in the detector as well as its description in the Monte Carlo simulation are discussed in detail.

The Optical System for the Large Size Telescope of the Cherenkov Telescope Array

The Large Size Telescope (LST) of the Cherenkov Telescope Array (CTA) is designed to achieve a threshold energy of 20GeV. The LST optics is composed of one parabolic primary mirror 23m in diameter and 28m focal length. The reflector dish is segmented in 198 hexagonal, 1.51m flat to flat mirrors. The total effective reflective area, taking into account the shadow of the mechanical structure, is about 368m 2 . The mirrors have a sandwich structure consisting of a glass sheet of 2.7mm thickness, aluminum honeycomb of 60mm thickness, and another glass sheet on the rear, and have a total weight about 47kg. The mirror surface is produced using a sputtering deposition technique to apply a 5-layer coating, and the mirrors reach a reflectivity of � 94% at peak. The mirror facets are actively aligned during operations by an active mirror control system, using actuators, CMOS cameras and a reference laser. Each mirror facet carries a CMOS camera, which measures the position of the light spot of the optical axis reference laser on the target of the telescope camera. The two actuators and the universal joint of each mirror facet are respectively fixed to three neighboring joints of the dish space frame, via specially designed interface plate.

FlashCam: a novel Cherenkov telescope camera with continuous signal digitization

The Cherenkov Telescope Array (CTA) will be the next generation ground-based observatory for cosmic gamma rays. The FlashCam camera for its mid-size telescope introduces a new concept, with a modest sampling rate of 250 MS/s, that enables a continuous digitization as well as event buffering and trigger processing using the same front-end FPGAs. The high performance Ethernet-based readout provides a dead-time free operation for event rates up to 30 kHz corresponding to a data rate of 2.0 GByte/s sent to the camera server. We present the camera design and the current status of the project.

LHCb Silicon Tracker DAQ and DCS online systems

The LHCb experiment at CERN is designed to perform precision measurements of b quark decays. The Silicon Tracker plays a crucial role in reconstructing particle trajectories and consists of two silicon micro-strip detectors, the Tracker Turicensis and the Inner Tracker. The radiation environment and the magnetic field represent new challenges for the implementation of the Experiment Control System (ECS) and the data acquisition (DAQ). The DAQ has to deal with ~272 000 analog read-out channels and real-time DAQ at a rate of ~ 1.1 MHz with data processing at the Trigger Electronics and L1 (TELL1) board level. The TELL1 real-time algorithms for clustering thresholds and other computations run on dedicated FPGAs. After data processing the total throughput amounts to about 6.4 GB from an input data rate of ~ 337 GB per second. The ECS is based on the hierarchical finite state machine paradigm and allows distributed control access and multi-platform use. The ECS is able to control and monitor the detector hardware infrastructure (power supplies, DAQ electronics ...) as well as monitor the environmental parameters. It can also take automated actions on warnings or alarms. Finally a completely independent, hardware based safety system ensures the detector safe operation.The LHCb experiment at the Large Hadron Collider (LHC) at CERN in Geneva (Switzerland) is designed to perform precision measurements of b quark decays. The Silicon Tracker (ST) plays a crucial role in reconstructing particle trajectories and consists of two silicon micro-strip detectors, the Tracker Turicensis upstream of the LHCb magnet and the Inner Tracker downstream. The radiation environment and the magnetic field represent new challenges for the implementation of a Detector Control System (DCS) and the data acquisition (DAQ).

Trigger performance verification of the FlashCam prototype camera

Abstract FlashCam is a camera proposed for the medium-sized telescopes of the Cherenkov Telescope Array (CTA). We compare camera trigger rates obtained from measurements with the camera prototype in the laboratory and Monte Carlo simulations, when scanning the parameter space of the fully-digital trigger logic and the intensity of a continuous light source mimicking the night sky background (NSB) during on-site operation. The comparisons of the measured data results to the Monte Carlo simulations are used to verify the FlashCam trigger logic and the expected trigger performance.