ALICE honours two Italian suppliers
During the ALICE week held in Bologna from 19 to 23 June, the Collaboration recognized two of its top suppliers.
It is in the picturesque city of Bologna that the ALICE Collaboration has rewarded two Italian suppliers, Istituto Trentino di Cultura ITC-irst (Trento) and MIPOT (Cormons), both involved in the construction of the Silicon Strip Detector (SSD) of the Inner Tracking System (ITS). ITC-irst has, in addition, provided tools for the computing project; thus, the ALICE Collaboration has decided to give a joint award to the two ITC-irst divisions: microtechnology and automated reasoning systems.
The ITS is the inner-most detector, located at the heart of the ALICE apparatus, very close to where collisions take place. The ITS consists of six cylindrical layers of silicon detectors, which identify the position of charged particles originating from the collision to a fraction of a millimeter. The SSD project is headed by Jean-Robert Lutz from IPHC Strasbourg and Gert Jan Nooren from Nikhef Utrecht, and its construction involves eleven European institutes (University of Jyvaskyla/Helsinki, SRTIIM Kharkov, ITP Kiev, SUBATECH Nantes, NIHKEF Amsterdam, Utrecht University, IPHC Strasbourg, St-Petersburg University, INFN, Trieste University and Warsaw Technical University).
The SSD is composed of 1698 silicon strip modules, which provide a total of more than 2.7 million analog detection channels! Each silicon strip module consists of a silicon strip sensor coupled with its read-out electronics. The fabrication of such sensors and modules requires non-standard manufacture, custom-made equipment and highly skilled personnel.
The ITC-irst Microsystems Division has produced 600 silicon double-sided sensors, with a consistent quality and reliability. 'ITC-irst has delivered very reliable sensors from the beginning, meaning much in terms of time, at this has avoided changes in the design or in the fabrication process', explains Luciano Bosisio from Trieste University. Relationships between the ALICE Trieste SSD Team, in charge of testing and validating the sensors, and ITC-irst, have been excellent, also thanks to a long-standing collaboration started in 1994.
The company MIPOT S.P.A., located in Cormons, has assembled the silicon strip sensors with all the remaining elements necessary to produce the silicon strip modules, delivering 42% of the total amount. The very sophisticated design of the final module required many original solutions and complex assembly tooling. 'MIPOT's engineers have used high-tech, efficient and fast procedures, bringing solutions that have been helpful for the other production sites in Helsinki and in Strasbourg', underlines Giacomo Vito Margagliotti from Trieste University. As with ITC-irst, MIPOT, the INFN and Trieste University had a continuous, positive and excellent collaboration, which started 18 years ago.
ITC-irst was also rewarded for its important contribution to another project, the offline computing of the ALICE experiment. The Division of Automated Reasoning Systems has provided ALICE with the RuleChecker. This software, which periodically checks the successive releases of the ALICE code, produces a report if any of the coding conventions adopted by the ALICE experiment are violated. Keeping control on and improving the code quality are challenging tasks in the context of high-energy physics software, which involves complex systems and worldwide-distributed developer teams. Federico Carminati, Project Leader of the ALICE computing project, stresses the high quality and uniqueness of the final product, as no equivalent among commercial and open source tools can be found.
