Beam phase and intensity monitor (BPIM) for the LHCb Experiment

The LHC bunch clock is transmitted over kilometres of fibre to the experiments where it is distributed to thousands of front-end electronics boards. In order to ensure that the detector signals are sampled properly, its long-term stability with respect to the bunch arrival times must be monitored with a precision of <100ps. In addition it is important to monitor the trigger conditions by measuring the intensity of each bunch locally in the experiment. For this purpose, we propose a beam phase and intensity acquisition board (BPIM) for the Button Electrode Beam Pick-ups which will be installed on both sides of the LHCb interaction point. The board measures the two quantities per bunch, and processes the information in an onboard FPGA. The information is read-out by the Experiment Control System and is directly fed to the LHCb Timing and Fast Control (TFC) [1]. In the TFC system the information is included in an event data bank but may also be used as a bunch crossing trigger or gate

A 40 MHz Trigger-free Readout Architecture for the LHCb experiment at CERN

LHCb is considering an upgrade towards a full 40 MHz readout. In this paper we investigate possibilities for a new Timing and Fast Control (TFC) system based on completely new technologies, and the consequences for the readout electronics. We define the requirements and propose an architecture allowing partitioning, complete readout control and event management. The backbone is based on bidirectional high-speed optical links using the latest FPGA transceivers. For the Front-End Electronics we advocate exploiting the bidirectional capability of the CERN GigaBit Transceiver to make the Readout Boards the TFC and the Control System interface to the Front-En

A 40 MHz Trigger-free Readout Architecture for the LHCb Experiment

The LHCb experiment is considering an upgrade towards a trigger-free 40 MHz complete event readout in which the event selection will only be performed on a processing farm by a high-level software trigger with access to all detector information. This would allow operating LHCb at ten times the current design luminosity and improving the trigger efficiencies in order to collect more than ten times the statistics foreseen in the first phase. In this paper we present the new architecture in consideration. In particular, we investigate new technologies and protocols for the distribution of timing and synchronous control commands, and rate control. This so called Timing and Fast Control (TFC) system will also perform a central destination control for the events and manage the load balancing of the readout network and the event filter farm. The TFC system will be centred on a single FPGA-based multimaster allowing concurrent stand-alone operation of any subset of sub-detectors. The TFC distribution network under investigation will consist of a bidirectional optical network based on the high-speed transceivers embedded in the latest generation of FPGAs with special measures to have full control of the phase and latency of the transmitted clock and information. Since data zero-suppression will be performed at the detector front-ends, the readout is effectively asynchronous and will require that the synchronous control information carry event identifiers to allow realignment and synchronization checks

The LHCb Timing and Fast Control system

In this paper we describe the LHCb Timing and Fast Control (TFC) system. It is different from that of the other LHC experiments in that it has to support two levels of high-rate triggers. Furthermore, emphasis has been put on partitioning and on locating the TFC mastership in one type of module: the Readout Supervisor. The Readout Supervisor handles all timing, trigger, and control command distribution. It generates auto-triggers as well as controls the trigger rates. Partitioning is handled by a programmable patch panel/switch introduced in the TTC distribution network between a pool of Readout Supervisors and the Front-End electronics. I

Cepheids and Long Period Variables in M33

We are conducting a long-term photometric survey of the nearby galaxy M33 to discover Cepheids, eclipsing binaries, and long-period variables. The dataset combines previously-obtained optical images from the DIRECT project with new observations acquired at the WIYN 3.5m telescope. The entire data set spans over 7 years with excellent synoptic coverage which will enable the discovery and characterization of stars displaying variability over a wide range of timescales (days, weeks, months, years). In this preliminary work we show representative light curves of different variables we found so far in two fields, color-magnitude diagrams, and optical Cepheid Period-Luminosity relations for M33. The ultimate goal of the project is to provide an absolute calibration of the Cepheid Period-Luminosity relation, and to study its metallicity dependence at optical wavelengths.Comment: 3 pages, 6 figures. To appear in "Stellar Pulsation: Challenges for Theory and Observation", Eds. J. Guzik and P. Bradle

Invasive alien species as reservoirs for pathogens

Alien plant and animal hosts play an important role as vectors of dangerous pathogens. However, the knowledge on pathogens of many host species is still limited. To bridge this gap, we collated information on pathogens carried by 118 alien species in Europe in their native and secondary range. In Europe, these species are considered as invasive. Using the dataset we determined most prevailing pathogen groups and plant and animal hosts that carried the highest number of pathogens. The most numerous pathogens were bacteria Xylella fastidiosa (plants) and Rabies virus (animals). The principal pathogen groups among plant hosts were Arthropoda (phylum), Insecta (class) and Hemiptera (order), and among animal hosts – Platyhelminthes (phylum), Trematoda (class) and Plagiorchiida/Strongylida (order). In plants, the highest number of pathogens was recorded for Ambrosia artemisiifolia; in animals, Procyon lotor was the most infested species. Hosts introduced from North America carried the highest numbers of pathogen species; in addition, unintentionally introduced hosts carried more pathogens than those introduced intentionally. We revealed also that the level of infestation differs between the habitats in which the hosts occur. It should be also stressed that in all analyses the number of pathogens increased with the number of publications on the particular host’ infestation. The highest number of publications was available for species useful for human, such as Crassostrea gigas. The results demonstrated that there are still significant gaps in the knowledge on the role of other hosts, including invasive ones (e.g., Sciurus niger) in pathogen transmission