UV Light Shower Simulator for Fluorescence and Cerenkov Radiation Studies

All experiments observing showers light use telescopes equipped with pixellised photodetectors. Monte-Carlo (MC) simulations of the apparatus operation in various situations (background light, shower energy, proximity of tracks...) are mandatory, but never enter into detector details like pulse shape, dead-time, or charge space effects which are finally responsible for the data quality. An apparatus where each pixel receives light from individual 370 nm UV LEDs through silica fibers is being built. The LEDs receive voltage through DACs, which get their input (which pixel, at what time, which amplitude) from a shower plus noise generator code. The typical time constant of a shower being one $/mu$s (300 m for light), the pulses are one $/mu$s wide. This is rather long compared to the intrinsic time constant (around 10 ns) of the light detectors, hence, these see "constant light" changing every $/mu$s. This is where important loading effects which are not included in MC code can be observed. The fibers illuminate the pixels through a diffuser, and each fiber illuminates only one pixel. The number of equipped pixels is such that it englobes a full shower (much less than the full focal surface). Finally, this equipment can be used also to calibrate the pixels

A sparse data scan circuit for pixel detector readout

This paper presents a collective analytic work on the document in its transition to digital form carried out within a network of researchers of the CNRS Information and Communication Science and Technology (STIC) Department. The collective drafting of a text, carried out with a device of annotations, built an analytical inventory of research in progress. It stressed three topics: the form, the text and the medium which reflect the radical transformations that are taking place and the issues still going on. In particular, the more and more dynamic construction of documents actually transforms their traditional stability. The advance of the collective thought could lead to the development of a theory of the document

The Simbol-X Anticoincidence

ISBN: 978-0-07354-0662-9International audienceThe Simbol-X telescope will be constitued by two satellites in formation flight. One will host the mirror module and the other the detector payload. This payload will be built with two main detectors able to measure the position, energy and arrival time of each focused photon, between 0.5 and 80 keV. The high sensitivity required by Simbol-X will necessitate low noise background detectors. To achieve this goal, those detectors will be surrounded by a passive graded shield, aimed to stop the out of field of view photons, and an active anticoïncidence system to tag the passing particles. This anticoïncidence detector, whose conception, optimisation and realization are under responsibility of the APC Laboratory, Paris, is based on plastic scintillator plates associated to multi-anodes photo-multipliers via optical fibers. In this paper, we will present the present status of the anticoïncidence system and its expected performances

Large scale pixel detectors for Delphi at LEP200 and atlas at LHC

Within the framework of an epistemological project, a short critical study of five directing scientific principles, characteristic of the new informational paradigms which are present today in electronic information science and technology, is presented. In this discipline, either on the level of scientific knowledge construction or on the level of scientific information production, communication and use, new intellectual reinforcements are mobilized. Strong scientific principles exist and characterize new scientific paradigms. Adopted by some information scientists, thwarted or diverted by others, they are more or less fixed. Moreover, strong sociological, economic and political determinants come to scramble them and technological outburst, although accepted, adds a strong instability