The ALICE DAQ: Current Status and Future Challenges

Proposal of abstract for CHEP2000The ALICE DAQ system has been designed to support an aggregate eventr building bandwidth of up to 2.5 GByte/s and a storage capability o fup to 1.25 GByte/s to mass storage.A general framework called the ALICE Data Acquisition Test Environment (DATE) system has been developed as a basis for prototyping the components of the DAQ. DATE supports a wide spectrum of configurations from simple systems to more complex systems with multiple detectors and multiple event builders.Prototypes of several key components of the ALICE DAQ have been developed and integrated with the DATE system, such as the ALICE Detector Data Link, the online data monitoring from ROOT and the interface to the Mass Storage systems. Combined tests of several of these components are pursued during the ALICE Data Challenges.The architecture of the ALICE DAQ system will be presented together with the current status of the different prototypes. The recent addition of a Transition Radiation Detector (TRD) to ALICE has required a revision of the requirements and the architecture of the DAQ. This will allow a higher level of data selection. These new opportunities and implementation challenges will also be presented

ALICE: Physics Performance Report, Volume I

ALICE is a general-purpose heavy-ion experiment designed to study the physics of strongly interacting matter and the quark-gluon plasma in nucleus-nucleus collisions at the LHC. It currently includes more than 900 physicists and senior engineers, from both nuclear and high-energy physics, from about 80 institutions in 28 countries. The experiment was approved in February 1997. The detailed design of the different detector systems has been laid down in a number of Technical Design Reports issued between mid-1998 and the end of 2001 and construction has started for most detectors. Since the last comprehensive information on detector and physics performance was published in the ALICE Technical Proposal in 1996, the detector as well as simulation, reconstruction and analysis software have undergone significant development. The Physics Performance Report (PPR) will give an updated and comprehensive summary of the current status and performance of the various ALICE subsystems, including updates to the Technical Design Reports, where appropriate, as well as a description of systems which have not been published in a Technical Design Report. The PPR will be published in two volumes. The current Volume I contains: 1. a short theoretical overview and an extensive reference list concerning the physics topics of interest to ALICE, 2. relevant experimental conditions at the LHC, 3. a short summary and update of the subsystem designs, and 4. a description of the offline framework and Monte Carlo generators. Volume II, which will be published separately, will contain detailed simulations of combined detector performance, event reconstruction, and analysis of a representative sample of relevant physics observables from global event characteristics to hard processes

Physical countermeasures to sustain acceptable living and working conditions in radioactively contaminated residential areas

The Chernobyl accident highlighted the need in nuclear preparedness for robust, effective and sustainable countermeasure strategies for restoration of radioactively contaminated residential areas. Under the EC-supporter STRATEGY project a series of investigations were made of countermeasures that were deemed potentially applicable for implementation in such events in European Member States. The findings are presented in this report, in a standardised data sheet format to clarify the features of the individual methods and facilitate intercomparison. The aspects of averted doses and management of wastes generated by countermeasures had to be described separately to provide room for the required level of detail. The information is mainly intended as a tool for decision makers and planners and constitutes of basis for the STRATEGY decision framework for remediation of contaminated urban areas. (au

Holistic countermeasures evaluation and the sustainable restoration and long-term management of contaminated rural, urban and industrial ecosystems

Both urban (including industrial) and rural environments may be contaminated for many years after a nuclear accident. To sustain acceptable living and working conditions, the capability to implement robust and effective restoration strategies is required. The criteria on which countermeasures are evaluated need to be extended from simply effectiveness and radiological protection criteria to a more integrated, holistic approach. Specifically, aspects such as whether measures can be practically applied, incur considerable direct or indirect (or side-effect) costs, have significant environmental effects, and are acceptable to society need to be incorporated. In addition, we should explore suitable approaches for successfully communicating with a wide range of stakeholders. Remediation following an accident cannot be based upon the evaluation of individual countermeasures in isolation; rather optimal strategies which combine a number of countermeasures need to be designed. A developing methodology to optimise restoration strategies is discussed using the results of an evaluation of a hypothetical accident. This initial evaluation is restricted to countermeasures that reduce ingestion doses and considers the effect of environmental restrictions, and dose distribution on the selection of remediation strategies. Communication strategies to be used within restoration are also discusse

Radionuclides in fruit systems: Model prediction-experimental data intercomparison study

This paper presents results from an international exercise undertaken to test model predictions against an independent data set for the transfer of radioactivity to fruit. Six models with various structures and complexity participated in this exercise. Predictions from these models were compared against independent experimental measurements on the transfer of 134Cs and 85Sr via leaf-to-fruit and soil-to-fruit in strawberry plants after an acute release. Foliar contamination was carried out through wet deposition on the plant at two different growing stages, anthesis and ripening, while soil contamination was effected at anthesis only. In the case of foliar contamination, predicted values are within the same order of magnitude as the measured values for both radionuclides, while in the case of soil contamination models tend to under-predict by up to three orders of magnitude for 134Cs, while differences for 85Sr are lower. Performance of models against experimental data is discussed together with the lessons learned from this exercise. © 2005 Elsevier B.V. All rights reserved

A wider perspective on the selection of countermeasures

In the past, the decision to apply countermeasures following nuclear accidents has been based primarily on their effectiveness in averting dose to man. However, particularly in recent years since the Chernobyl accident in 1986, it has been realised that other factors also need to be considered. These include the reasons and justification for introducing the countermeasure, the time scale over which they will be used, their effectiveness and their practicability. Practicability includes factors such as technical limitations and capacity, exposure during implementation, potential environmental impacts, economic implications and acceptability (both social and ethical) as well as a number of site specific issues. These criteria have been used to evaluate a range of commonly used countermeasures and a spreadsheet information system has been prepared by the members of an IUR Action Group. The system highlights factors to be taken into consideration in making a decision on the implementation of countermeasures