For this experiment, the department participated in the integration of the optical modules of the detector as well as in the activities of tests and checks of the matrix consisted of 1600 photomultipliers (PM).
This integration consisted in the assembly of the focal plan which consists of 25 modules containing each 4 sub-modules. Every sub-module is equipped with 16 photomultipliers. The PM was beforehand coupled according to their sizes and to their gain and their implementation (equipment) was made according to this information.
A seal between the printed circuit and the PM base was set up for "potting", insulating PM electrodes at high voltage. It eliminates low-pressure strains. At low voltage, the more air pressure decreases and the more electric shock rises. The curve of Paschen, representing strain voltage as a function of inter-electrodes distance and pressure, has a minimal value called Paschen minimum.
"Potting" was made by injecting a resin of type Mapsil 213 B, 13 grams of product were used by sub-module and 18 minutes on average are necessary for every injection, polymerization being made at ambient temperature.
An operation of "coating" was then made for the same reasons as previously (Paschen). It consists in soaking every sub-module, at the level of the printed circuit and on every component, with a resin (Nusil CV1152), applied to the brush, which insures a protection of surface. This activity required the putting in steam room of sub-modules for 6 hours in 40 ° C.
Finally, the third operation was also realized to avoid the strains. This one corresponds to the addition of a layer of micro balloons (micro glass balls) mixed in the resin (Mapsil 213 B), and applied by syringe on the reverse of sub-module. Tests of every sub-module at high-voltage and vacuum were then led to verify that there were no strains in the passage of Paschen minimum.
The integration continues then by the assembly of sub-modules on the railing support, the check of the focal plan, the mechanical tightening and the implementation of optical fibers of test. The assembly of the electronic boards of "Front-end" acquisition is then made with the implementation of the thermal bridges on the railing support to evacuate the heat via the small columns of assembly of modules.
To finish, having equipped the focal plan of probes of temperature, circuits of connection of type " Flex " and supplies, the plan of tiles of aérogel is installed. It is constituted of two sheets of Mylar tense and stuck on an aluminum frame containing the tiles of aérogel. Two mechanical protections of nest of bee type are then installed on the front and on the back of the device.
All these operations required not far from 12 working months, from January, 2006 till January, 2007.
Contact : Marc Marton
On the LOHENGRIN experiment installed at ILL (Laue Langevin Institut), the SDI opearted on of a double small detector with neutrons manufacturing, with reading of current on the anodes XY wires composed of 4 cathode plans and of 8 anode plans (outside dimensions 75 mm × 38 mm), the useful window of detection of 20 mm by 20 mm. This activity, which took place in the year 2007, corresponds to :
- The manufacturing of 4 cathodes plans stuck, that is 4 times 2 frames FR4/Cu, 2 faces of 16/10 of mm of thickness. These two frames are in coincidence with, in the middle, a window of Mylar aluminised, 2 faces of 23 µm, with the HV supply contacts.
- The weaving of 2 wires plans (aluminum frames 250 × 140 × 10 mm). The wires are W/Au/Re of 30 µm, with a tension of 30 g, a tep of 1 mm, that is 115 wires/frame, for transfer on frames anodes.
- The transfer, the welds and the cuttings of the wires on the frames pads of XY anodes. There is 4 XY groups, that means 8 frames of FR4/Cu, two faces of 16/10 of thickness.
Planck satellite - Functional Tests
After Planck satellite control system prototype 20K cryo-generator (Sorption Coolers Electronic, SCE) tests successes in 2003, the manufacturing of the qualification and flight models were confided to EADS-CRISA (space industry), in Spain, at the beginning of 2004.
The delivery of the first qualification model (EQM) during the curse of 2004 permitted to realize the coupled tests with the flight cryo-generator at the end of the year, again on JPL's site, NASA laboratory at Pasadena, USA.
The department was responsible here for the organization of these tests as well as the software development of the tools of piloting and tests, developed under LabVIEW. The realization of the it test first ones with the flight cryo-generator, led in close collaboration with the electronics department of the laboratory, were, even there, successful and allowed the development of the embedeed software for which the laboratory is responsible.
The second qualification model ( CQM), identical in all to the future flight models but built with not spatial qualified components, was delivered to us at the beginning of year 2005. The department organized the second campaign of test at the JPL in spring, 2005, always coupled with the flight cryo-generator, just before its delivery in Europe. This last campaign in the USA allowed to test several specific procedures recently implemented in the embedeed software, among which the procedures of automatic covering of functioning error, necessary for enhanced reliability of the system during flight.
During the beginning of the first half of the year 2006, EADS-CRISA delivered three flight models of the electronic case SCE, two models which will be integrated on the satellite (FM1 and FM2) and an extra model (PFM). The SDI was responsible for the implementation and the execution of the functional tests on these cases, according to the current spatial quality plan, in the ESA standards.
These tests took place at the LPSC in clean room, until June, 2006, date in which the electronics FM1 and FM2 was delivered to the satellite's manufacturer (Thales Alenia Space in Cannes) for integration.
In parallel to these functional tests, a campaign of cryogenic validation tests took place in spring 2006, implementing both flight Sorption Coolers integrated on the Planck satellite's qualification model, in association with the SCE qualification model case (CQM) that had been tested and delivered by the end of 2005. These tests took place over several weeks at the Liege Space Center (CSL - Belgium). It allowed to validate part of the cryogenic aspects of the Sorption Cooler and of its control electronics housing.
At the end of the year on 2006, the qualification SCE housing was re-qualified in avionic housing (AVM) to be a part of avionic tests on a satellite's model. These tests, which focus essentially on the electric aspects of the satellite service module interface took place on several days, at Thales Alenia Space (Torino, Italy).
Finally, at the beginning of year 2007, again avionic tests took place, but this time by piloting the electronic housing from "Operating Center Mission" of the ESA (MOC), located in Darmstadt in Germany.
The SDI completely organized and widely participated in all these tests, both in the LPSC and on sites.
In 2008, the satellite is transferred on the Ariane Space's launch site at Kourou in Guiana. And even there, the SDI participates in the cryogenic tests and of pre-launch of the satellite.
After the satellite's launch, again, the department took an important part in the post-launch operations of Mission Operating Center (MOC) of the ESA, at Darmstadt in Germany.
Planck satellite - Units Testing
In parallel, during summer, 2004, an activity of test and systematic validation of the spatial embedeed software by the SCE began. This process added to the development aims at enhancing reliability of the software in all its scales (unit functions, integrated modules and system on target). It requires the help of several testers, a strong implication of programmers and system engineers, and the use of a more familiar methodology from transport industry or defense than laboratories.
SDI, already strongly involved in the Planck systems test in the LPSC, was in charge of coordination and of project management of this work, at the boundary of the electronics, computing, system and test methods. A test team was established with persons of the various departments of the laboratory, but also researchers of the LPSC's Planck group.
A first iteration of unit testing was confided to a specialized provider, CAPTEC, recommended by the European Space Agency. This major stage however showed its limits: later evolutions of the software questioned most of the validation obtained in this period, and then the provider restricted the field of his responsibilities to modules of which he mastered best the testing.
At the beginning of 2005, this service ended and the objective remained to finish the critical module delivery test, a "boot" software, which cannot be anymore modified once implanted in the electronics. The test software team took up this challenge by using partially the example and the previous results, for one somewhere else the expertise of the Grenoble Computing Laboratory (LIG - INPG / UJF / CNRS), interested in our nitiative, and finally of a good dose of imagination and practical spirit.
Until September, 2005, two trainees of the LIG also made an important contribution by completing the unit testing on the "application" software part using Cantata++ testing software. This last phase formally closed at the beginning of 2006, but scripts and testing tools have remained inseparable of the software during its whole life.
Auger - Low Frequency Radiodetection R&D
For the program of R&D "RAuger" on the radio detection of cosmic rays, three devices of autonomous radio detection were developed and installed on the site in Argentina, in association with Subatech, Nantes. The SDI made an important contribution for this activity by developing the power supply part by solar panels and batteries, as well as the mechanical supportof the set.
We also took in charge the part transport and logistics of the whole device and actively participated in its on site implementation in a first mission in 2006 then its upgrade in the second mission in 2007.
Contact : Patrick Stassi
Within the CODALEMA experiment framework which the LPSC joined in the year 2005, in association with the Subatech laboratory in Nantes, the SDI designed and deployed in autumn, 2005, a network of cosmic rays detections, composed of five stations of detectors with scintillators and photomultipliers. These detectors are had on both sides the network of décamétric antennas, exploited for the detection of the radio waves emitted by the cosmic sparks.
The acquisition system of these detectors is based, at the material point of view, MATACQ cards type VME, developped by the LAL and the IRFU (ex DAPNIA), so as to be able to become integrated into the system existing on the antenna network. The department implemented this acquisition and developed several programs under LabVIEW allowing to get back and store data, to make an on-line control of the rates of events as well as the piloting of the photomultipliers high voltages.
By means of the IT service of the LPSC, an automatic backup system of the data was set up and checks it remotely. The experiment can be made in a way secured way through the Internet network.
The installation of the CODALEMA experiment, on the site of the radio telescope of Nançay, continued until 2007. The department deployed four new stations of scintillators detection in March, 2006, so coming to complete 5 stations already installed in 2005. The capture of data with this network of new detectors continued till the end of 2006.
In January, 2007, in difficult weather conditions, the department again installed four new detection stations, so completing the network of thirteen scintillators detectors planned at the origin of the project.
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