Powder/die friction in the spark plasma sintering process: Modelling and experimental identification

The powder/die friction phenomenon is known to generate densification inhomogeneities in the spark plasma sintered sample. The measurement of a powder/solid friction coefficient at high temperature is very difficult if not impossible by classical means. Then, an experimental/simulation method of identification of the friction coefficient based on the sample displacement field is introduced. This reveals that the friction of contact type powder/wall is low and about 0.1 and the friction type powder/graphite-foil/wall is close to zero. The relative density inhomogeneities are limited to a maximum difference of 3%

CASTOR status and evolution

In January 1999, CERN began to develop CASTOR ("CERN Advanced STORage manager"). This Hierarchical Storage Manager targetted at HEP applications has been in full production at CERN since May 2001. It now contains more than two Petabyte of data in roughly 9 million files. In 2002, 350 Terabytes of data were stored for COMPASS at 45 MB/s and a Data Challenge was run for ALICE in preparation for the LHC startup in 2007 and sustained a data transfer to tape of 300 MB/s for one week (180 TB). The major functionality improvements were the support for files larger than 2 GB (in collaboration with IN2P3) and the development of Grid interfaces to CASTOR: GridFTP and SRM ("Storage Resource Manager"). An ongoing effort is taking place to copy the existing data from obsolete media like 9940 A to better cost effective offerings. CASTOR has also been deployed at several HEP sites with little effort. In 2003, we plan to continue working on Grid interfaces and to improve performance not only for Central Data Recording but also for Data Analysis applications where thousands of processes possibly access the same hot data. This could imply the selection of another filesystem or the use of replication (hardware or software).Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 2 pages, PDF. PSN TUDT00