No abstract available

[en] This paper presents the experimental results of radiation hardness studies of the vertex detector readout chip for the BaBar experiment. The chip was fabricated in a rad-hard CMOS technology. It was irradiated in several steps by ⁶⁰Co γ-rays to a total dose of 2.4 Mrad. After irradiation, the chip is fully functional, with small parameter degradation. This analysis demonstrates that the chip can operate throughout the lifetime of the detector, always meeting the primary performance criteria

[en] An analog signal processor based on the Time-over-Threshold (ToT) range compression is employed in the front-end section of the readout chip of the microstrip vertex detector for the BaBar experiment. The paper, after describing the circuit solutions that have been adopted to optimize the ToT operation, focuses on the noise aspects of the ToT processor. Comparisons are made between the signal-to-noise ratio in the linear processor preceding the ToT circuit and that obtained at the output of the entire analog channel including the ToT function

[en] The three-dimensional luminosity distribution at the interaction point (IP) of the SLAC B-Factory is measured continuously, using e⁺e^- → e⁺e^-, μ⁺μ^- events reconstructed online in the BABAR detector. The centroid of the transverse luminosity profile provides a very precise and reliable monitor of medium- and long-term orbit drifts at the IP. The longitudinal centroid is sensitive to variations in the relative RF phase of the colliding beams, both over time and differentially along the bunch train. The measured horizontal r.m.s. width of the distribution is consistent with a sizeable dynamic-β effect; it is also useful as a benchmark of strong-strong beam-beam simulations. The longitudinal luminosity distribution depends on the e^± bunch lengths and vertical IP β-functions, which can be different in the high- and low-energy rings. Using independent estimates of the βfunctions, we analyze the longitudinal shape of the luminosity distribution in the presence of controlled variations in accelerating RF voltage and/or beam current, to extract measurements of the e⁺ and e^- bunch lengths

[en] The BaBar data acquisition system (DAQ) transports data from the detector front end electronics to short term disk storage. A monitoring application (VMON) has been developed to monitor the one hundred and ninety computers in the dataflow system. Performance information for each CPU is collected and multicast across the existing data transport network. The packets are currently collected by a single UNIX workstation and archived. A ROOT based GUI provides control and displays the DAQ performance in real time. The same GUI is reused to recover archived VMON data. VMON has been deployed and constantly monitors the BaBar dataflow system. It has been used for diagnostics and provides input to models projecting future performance. The application has no measurable impact on data taking, responds instantaneously on the human timescale to requests for information display, and uses only 3% of a 300 MHz Sun Ultra5 CPU

[en] The SLAC RCE platform is a general purpose clustered data acquisition system implemented on a custom ATCA compliant blade, called the Cluster On Board (COB). The core of the system is the Reconfigurable Cluster Element (RCE), which is a system-on-chip design based upon the Xilinx Zynq family of FPGAs, mounted on custom COB daughter-boards. The Zynq architecture couples a dual core ARM Cortex A9 based processor with a high performance 28nm FPGA. The RCE has 12 external general purpose bi-directional high speed links, each supporting serial rates of up to 12Gbps. 8 RCE nodes are included on a COB, each with a 10Gbps connection to an on-board 24-port Ethernet switch integrated circuit. The COB is designed to be used with a standard full-mesh ATCA backplane allowing multiple RCE nodes to be tightly interconnected with minimal interconnect latency. Multiple shelves can be clustered using the front panel 10-gbps connections. The COB also supports local and inter-blade timing and trigger distribution. An experiment specific Rear Transition Module adapts the 96 high speed serial links to specific experiments and allows an experiment-specific timing and busy feedback connection. This coupling of processors with a high performance FPGA fabric in a low latency, multiple node cluster allows high speed data processing that can be easily adapted to any physics experiment. RTEMS and Linux are both ported to the module. The RCE has been used or is the baseline for several current and proposed experiments (LCLS, HPS, LSST, ATLAS-CSC, LBNE, DarkSide, ILC-SiD, etc).

[en] The Energy Sciences Network (ESnet) is the primary provider of network connectivity for the US Department of Energy Office of Science (SC), the single largest supporter of basic research in the physical sciences in the United States. In support of the Office of Science programs, ESnet regularly updates and refreshes its understanding of the networking requirements of the instruments, facilities, scientists, and science programs that it serves. This focus has helped ESnet to be a highly successful enabler of scientific discovery for over 20 years.

No abstract available

[en] The Silicon Vertex Tracker (SVT) of the BABAR experiment at the PEP-II asymmetric B factory is a crucial element of the BABAR physics program. The SVT is a five layer device with double-sided silicon strip detectors and a custom readout chip based on a time-over-threshold circuit. The SVT is fully operational since the installation in the experiment in 1999. We briefly review the detector performance after more than 3 years of data taking in factory mode. The high-luminosity running of PEP-II through the end of the decade will increase the radiation level in the SVT above its design limit. Radiation issues will be reviewed and results from radiation tests of the various detector components will be presented. We finally discuss the outlook for the long-term running of the SVT

[en] A brief summary of the design goals, description, and performance of the BABAR Silicon Vertex Tracker is given. Results from radiation hardness tests are discussed, which indicate satisfactory operation up to 5 Mrad of accumulated radiation. The local alignment procedure has made significant improvements recently, and four readout sections were recovered during the BABAR shutdown in 2002