Monitoring the BaBar Data Acquisition System

The BaBar data acquisition system(DAQ)transports data from the detector front end eletronics 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 300MHz Sun Ultra5 CPU.     

User‘s Friendly Interface to the CDF Data Handling System

The CDF collaboration at the Fermilab Tevatron analyses proton-antiproton interactions at a center-of=mass energy of 2 TeV.during the the collider run starting this year the experiment expects to record 1 Petabyte of data and associated data samples,The Data Handling(DH) system has online and offline components.The DH offline component provides access to the stored data,to stored reconstruction output,to stored Monte-Carlo data samples,and user owned data samples.It serves more than 450 physicists of the collaboration.The extra requirements to the offline component of the Data Handling system are simplicity and convenience for users.More than 50 million events of the CDF Run II data have been already processed using this system.     

Operation and Optimization of a Linux PC farm for Physics Analysis in the ZEUS Experiment

The ZEUS experiment has migrated its reconstruction and analysis farms to a PC-based environment.More than one year of experience has been acquired with successful operation of an analysis farm designed for several hundred users.Specially designed software has been used to proveide fast and reliable access to large amounts of data (30 TB in total),After the ongoing upgrade of the HERA luminosity,higher requirements will arise in terms of data storage capacity and throughput rate,The necessity of a bigger disk cache has led to consideration of solutions based on commodity technology,PC-based file servers are being tested as a cost-effective storage system,In this article we present the hardware and software solutions deplogyed and discuss their performance.scalability and maintenance issues.     

The ALICE Data Challenges

Since 1998,the ALICE experiment and the CERN/IT division have jointly executed several large-scale high throughput distributed computing exercises:the ALICE data challenges.The goals of these regular exercises are to test hardware and software components of the data acqusition and computing systems in realistic conditions and to execute an early integration of the overall ALICE computing infrastructure.This paper reports on the third ALICE Data Challenge (ADC III) that has been performed at CERN from January to March 2001.The data used during the ADC Ⅲ are simulated physics raw data of the ALICE TPC,produced with the ALICE simulation program AliRoot.The data acquisition was based on the ALICE online framework called the ALICE Data Acquisition Test Environment (DATE) system.The data after event building,were then formatted with the ROOT I/O package and a data catalogue based on MySQl was established.The Mass Storage System used during ADC III is CASTOR.Different software tools have been used to monitor the performances,DATE has demonstrated performances of more than 500 MByte/s.An aggregate data throughput of 85 MByte/s was sutained in CASTOR over several days.The total collected data amounts to 100 TBytes in 100.00 files.     

Calibration of RPC-based muon detector at BESⅢ

The calibration algorithm for RPC-based muon detector at BESIII has been developed. The calibration method, calibration error and algorithm performance are studied. The primary results of efficiency and noise at layer, module and strip levels have been calibrated with cosmic ray data. The calibration constants are available for simulation and reconstruction tuning. The results of Monte Carlo and data are also compared to check the validation and reliability of the algorithm.     

Calibration of RPC-based muon detector at BESⅢ

The calibration algorithm for RPC-based muon detector at BESⅢ has been developed. The calibration method, calibration error and algorithm performance are studied. The primary results of efficiency and noise at layer, module and strip levels have been calibrated with cosmic ray data. The calibration constants are available for simulation and reconstruction tuning. The results of Monte Carlo and data are also compared to check the validation and reliability of the algorithm.     

Specification and Simulation of the ALICE Trigger and DAQ System

The ALICE Trigger and Data Acquisition (TRG/DAQ) System is required to support an aggregate event building bandwidth of up to 4 GByte/s and a storage capability of up to 1.25 GByte/s to mass storage.The system has been decomposed in a set of hardware and software components and prototypes of these components are being developed.It is necessary to verity the system design,its capability to reach the expected behavior and the target performances,discover possible bottlenecks and ways to correct for them,and explore alternative algorithms and new architectures.To achieve this the complete TRG/DAQ system has been formally specified.and the verification of the expected behavior has been performed through the execution of the specification,Two tools were used for this.Foresight,and Ptolemy.     

Timing system of HIRFL-CSR

The national science project HIRFL-CSR has recently been officially accepted. As a cyclotron and synchrotron complex, it puts some particularly high demands on the control system. There are hundreds of pieces of equipment that need to be synchronized. An integrated timing control system is built to meet these demands. The output rate and the accuracy of the controller are 16 bit/μs. The accuracy of the time delay reaches 40 ns. The timing control system is based on a typical event distribution system, which adopts the new event generation and the distribution scheme. The scheme of the timing control system with innovation points, the architecture and the implemented method are presented in the paper.     

Unified fission model for proton emission

The unified fission model （UFM） combining with the phenomenological assault frequency has been carried out to investigate the proton-radioactivity half-lives of spherical proton emitters. The results are in good agreement with the experimental data and other theoretical values, and newly observed spherical proton emitters have been analyzed. Finally, the effect of angular momentum transfer on half-life of proton emission has been discussed in detail and a formula can be used to describe this relationship.     

Quality control and database on resistive plate chambers for the BESⅢ experiment

The chamber production and installation of the BESⅢ MUON identifier system have been finished. The cosmic ray test result after installation shows that the average efficiency is bigger than 95% and can meet the requirement of the design report. A database including all the chamber parameters and performance data has been constructed and is accessible online. The quality control procedures during the production and the database are described.     

AN ULTRASONIC INSPECTION SYSTEM TO DETECT INTERNAL PIPES IN HOT STEEL BLOOM

The experimental pressure contact system with a single transducer has been developed to detect internalpipes and measure ultrasonic wave velocities at temperatures up to 1120℃ and 1300℃,respectively.In thispaper,the design of the system and the special hardware and software about the inspection and the signalprocessing are described;the relation between the echo amplitude and the pressure exerted is analysed,as wellas the formulas and some of the experimental results of pipe detecting are also given.An application has beenmade for a patent.     

Molecular dynamics study for the melting curve of MgO at high pressure

Shell-model molecular dynamics method is used to study the melting temperatures of MgO at elevated temperatures and high pressures using interaction potentials. Equations of state for MgO simulated by molecular dynamics are in good agreement with available experimental data. The pressure dependence of the melting curve of MgO has been calculated. The surface melting and superheating are considered in the correction of experimental data and the calculated values, respectively. The results of corrections are compared with those of previous work. The corrected melting temperature of MgO is consistent with corrected experimental measurements. The melting temperature of MgO up to 140GPa is calculated.     

Dedicated 4πβ(LS)-γ(HPGe) digital coincidence system based on synchronous high-speed multichannel data acquisition

A dedicated 4πβ(LS)-γ(HPGe) digital coincidence system with five acquisition channels has been developed. Three ADC acquisition channels with an acquisition resolution of 8 bits and acquisition rate of 1 GSPS are utilized to collect the signals from three PMTs which are used to detect β decay, and two acquisition channels with an acquisition resolution of 16 bits and acquisition rate of 50 MSPS are utilized to collect the signals from high-purity germanium(HPGe), which is used to detect γ decay. In order to increase the accuracy of the coincidence system, all five acquisition channels are synchronous within 500 ps. The data collected by the five acquisition channels will be transmitted to the host PC through a PCI bus and saved as a file. Off-line software is utilized for the 4πβ(LS)-γ(HPGe) coincidence and data analysis as needed in practical applications. Tests of the system show that system can record pulse signals from 4πβ(LS)-γ(HPGe) synchronously for further coincidence calculation and the highest coincidence rate of the system is 20 K/s, which is sufficient for most applications. Compared with traditional coincidence modules like MAC3, the digital coincidence system has a higher flexibility of coincidence algorithm. In addition, due to the use of ADC, the structure of the coincidence system is simplified. This paper introduces the design of the hardware, the synchronization method and the test results of this system.     

Farming Data for the HyperCP Experiment

The main goal of the HyperCP(E87) experiment at Fermilab is to search for CP violation in Ξand Α decays at the -10^-4 level.This level of precision dictates a data sample of over a billion events.The experiment collected about 231 billion raw events on about 30,000 5-GB tapes in ten months of running in 1997and 1999,In order to analyze this huge amount of data,the collaboration has reconstructed the events on a farm of 55 dual-processor Linux-based PCs at Fermilab.A set of farm tools has been written by the collaboration to interface with the Farm Batch System (FBS and FBSNG)[1] developed by the Fermilab Computing Division,to automate much of the farming and to allow nonexpert farm shifters to submit and monitor jobs through a web-based interface.Special care has been taken to produce a robust system which facilitates easy recovery from errors.The code has provisions for extensive monitoring of the data on a spill-by-spill basis,as is required by the need to minimize potential Systematic errors.About 36 million plots of various parameters produced from the farm analysis can be accessed through a data management system.The entire data set was farmed in eleven mouths,or about the same time that was taken to acquire the data.We will describe the architecture of the farm.our experience in operating it ,and show some results from the farm analysis.     

Similarity Solutions for Generalized Variable Coefficients Zakharov-Kuznetsov Equation under Some Integrability Conditions

In this paper, the symmetry method has been carried over to the generalized variable coefficients Zakharov- Kuznetsov equation. The infinitesimal symmetries and the optimal system are deduced and from this optimal system seven basic fields are determined, and for every vector field in the optimal system the admissible forms of the coefficients are found and this also leads us to transform the given equation into partial differential equations in two variables. After using some referenced transformations the mentioned partial differential equations eventually reduce to ordinary differential equations. The search for solutions to those equations has yielded many exact solutions in most cases.     

Reflection-Asymmetric Shell Model Description of the Neutron-Rich^142，145Ba Nuclei

The reflection asymmetric shell model has been applied to describe the octupole deformed bands in neutron-rich even-even ^142Ba and odd-N^145Ba nuclei. The alternating parity bands of ^142Ba and the simplex s = -i bands of^145Ba are calculated and compared with the available experimental data. The calculated results are in good agreement with the experimental data. The spin and parity assignments of ground-state of^145Ba are discussed.The results show that the present work is a useful attempt to further explore the nuclear reflection asymmetry in neutron rich region.     

Single-pulse CARS spectra in solid propellant combustion at atmosphere pressure

The unstable-resonator spatially enhanced detection (USED) coherent anti-stokes Raman spectroscopy (CARS) measurements of temperature and N2 concentration in the combustion of solid propellant at atmosphere pressure are reported. The USED CARS measurement system has a high spatial solution of ~ 0.1 mm in diameter and 3 mm in length, and permits instantaneous measurement at 10-Hz rate. The single-pulse N2 Q-branch CARS spectra have been obtained from the propellant combustion. The temperatures and N2 concentrations of the propellant flame at different height have been achieved by fitting the experimental data to theoretical spectra. The results indicate that the temperature is up to ~ 2500 K with N2 concentration in a range from 10% to 26%.     

CMS Grid Activities in Europe

The CMS experiment at the CERN LHC collider is producing large amounts of simulated data in order to provide an adequate statistic for the Trigger System design.These productions are performed in a distributed environment,prototyping the hierarchical model of LHC computing centers developed by MONARC.A GRID approach is being used for interconnecting the Regional Centers.The main issues which are currently addressed are:automatic submission of data production requests to available productioin sites,data transfer among production sites,“best-replica” location and submission of enduser analysis job to the appropriate Regional Center,In each production site different hardware configurations are being tested and exploited.Furthermore robust job submission systems.which are also able to provide the needed bookkeeping of the produced data are being developed.BOSS(Batch Object Submission System)is an interface to the local computing center scheduling system that has been developed in order to allow recording in a relational database of information produced by the jobe running on the batch facilities A summary of the current activites and a plan for the use of DataGrid PM9 tools are presented.     

Experience with the COMPASS Conditions Data Base

The COMPASS experiment at CERN is starting data taking in summer 2001,The COMPASS off-line framework(CORAL)will use the CERN Conditions Data Base(CDB)to handle time dependent quantities like calibration constants and data from the slow control system.We describe the use of the CDB within CORAL and the fullscale performance tests on the COMPASS Computing Farm(CCF),The CDB has been interfaced to the SCADA PVSS slow control system.To continuously transfer all the data to the CDB and make them available to the users,We describe this interface,a feasibility study performed using mock data and we predict the expected performance.