ATLAS - NSW (NEW SMALL WHEEL) MICROMEGAS DETECTORS Status on mechanical prototypes construction @ Saclay Patrick PONSOT for the Saclay ATLAS-Micromegas group MM weekly meeting – 3 rd of December 2013 Irfu.cea.fr
Outline M4 construction • General considerations • Status of the M4 construction Gluing of the panels with the stiffback Tooling to integrate the 4 meshes during the assembly Qualification of the sandwiches (material) and of their assembly (density of pillars inside the drift gap) • Definition of the mechanical characteristics Bending tests on a qualified machine • Testing with a 3 panels assembly Design and drawings of the spacer and supports for the assembly of the prototypes (Spacer@Freiburg, M1@LMU, M2@Roma, M3@Pavia, M4@Saclay) MM Weekly meeting - 3rd of December 2013 CEA-Saclay/DSM/Irfu - Patrick PONSOT | PAGE 2
M4 construction @ Saclay General considerations • The context inside our institute on 2013 is very critical better conditions are expected after the signing of the MoU Sharing of the technicians with other projects In almost of the cases, impossible to machine the pieces inside our mechanical workshop Companies are not reactive for small production (e.g. we lost 6 weeks by waiting the delivery of the M4-frames) • Infrastructures The existing cleaning rooms are completely busy until 2017 We decided to build a new one dedicated to the assembly of large detectors Part of the time is dedicated to the definition of this new cleaning room ISO-7 (specifications to take in account the tooling that we need) Delivery of the cleaning room is expected on 2015 for production The module zero must be built in the same temporary room as for prototypes Increasing of the work to reinforce the cleanliness and to adapt the tooling for this temporary room. MM Weekly meeting - 3rd of December 2013 CEA-Saclay/DSM/Irfu - Patrick PONSOT | PAGE 3
M4 construction @ Saclay General considerations • New cleaning room will be equipped with 2 granite tables specifications and general drawings are ongoing MM Weekly meeting - 3rd of December 2013 CEA-Saclay/DSM/Irfu - Patrick PONSOT | PAGE 4
M4 construction @ Saclay General considerations • Temporary room (used for the barrel alignment production) has been equipped with laminar airflux system cleanliness and tooling must be improved to build the M0 MM Weekly meeting - 3rd of December 2013 CEA-Saclay/DSM/Irfu - Patrick PONSOT | PAGE 5
M4 construction @ Saclay Status of the construction • M4 assembly will not be finished before the end of the year Gluing of the panels has just been begun +10 days Waiting for the 4 meshes and associate tooling done in the industry delivery expected on week 51 (last open week before Xmas vacation) Gluing of the pillars, mesh assembly, assembly of the module by gluing of the panels +10 days Due to the very bad tolerances that we found on the thickness of our aluminum honeycombs (~200 microns to compensate with the glue), few days have been dedicated to test the gluing procedure with the stiffback Bad result with the glue DP490 peeling is very easy and capillarity of the glue is very bad (not enough glue on the cells of the honeycombs) ~200 m We decided to use the glue 2011 for the M4 MM Weekly meeting - 3rd of December 2013 CEA-Saclay/DSM/Irfu - Patrick PONSOT | PAGE 6
M4 construction @ Saclay Status of the construction • Gluing of the panels is in progress First drift panel made with 2x4 FR4 skins and aluminum honeycombs (glue 2011) has been glued on this morning (second step with the stiffback) Preparation of the second gluing step Vacuum bag on the stiffback MM Weekly meeting - 3rd of December 2013 CEA-Saclay/DSM/Irfu - Patrick PONSOT | PAGE 7
M4 construction @ Saclay Drift panel assembly procedure MM Weekly meeting - 3rd of December 2013 CEA-Saclay/DSM/Irfu - Patrick PONSOT | PAGE 8
M4 construction @ Saclay Status of the construction / gluing of the mesh • Mesh fixation on the M4 prototype Simplified design just to be able to study the deformation of the panel with the tension of the mesh Common frame to close the gas-gap and to glue the mesh Source: Marabu 4 enlarge frames (with mesh glued on it) have been ordered in the Marabu company Delivery expected on week 51 • Transfer frame and mechanics to position it have been ordered machining is in progress Transfer frame is fixed on the mesh frame Mechanical adjustment to be in contact with the mesh during the gluing Cutting of the mesh Fixation on the panel Dismounting of the transfer frame and measurement of the deformation and of the tension MM Weekly meeting - 3rd of December 2013 CEA-Saclay/DSM/Irfu - Patrick PONSOT | PAGE 9
M4 construction @ Saclay Status of the construction / gluing of the mesh Mesh frame fixed on Enlarged frame with the the transfer frame mesh glued on it (provided by the industry) Transfer of the mesh Vertical adjustment system on the M4 frame MM Weekly meeting - 3rd of December 2013 CEA-Saclay/DSM/Irfu - Patrick PONSOT | PAGE 10
Qualification of the sandwiches and of their assembly What is the goal ? • A lot of simulation of the deformation of the MM sectors were done for the TDR, to evaluate the impact of the material on the layout The main deformation is coming from the thermal loading 2 parameters must be taken in account: the thermal behavior of the assembly of the panels and the stiffness of the panels • A minimal value for the equivalent Young modulus of the panels has been estimated 17GPa but: The segmentation has been changed (2 MM modules) The detail design was not taken in account (interconnections of the panel) Margin was applied on the boundary conditions: 2°C temperature gradient between the inner and outer panels (for commissioning on surface and running in the cavern) Don’t forget that we need to guaranty that we will have no failure during the assembly, storage and transportation • Now with prototype experience and detailed design, we can do the reverse way Qualification of the material and mechanical prototypes Full simulation of the MM sectors Identification of the margin to take the decision (Aluminum, Nomex or foam?) MM Weekly meeting - 3rd of December 2013 CEA-Saclay/DSM/Irfu - Patrick PONSOT | PAGE 11
Qualification of the sandwiches and of their assembly Qualification / equivalent mechanical characteristics (material) • A protocol for testing has been proposed by Saclay Bending test (3 points) on a qualified testing machine (2 Instron machines at Saclay) Testing of 3 samples Dimensions of the samples : 110mmx17mmx~10mm Measurement of the displacement according to the loading until the destroying of the sample • Calculation of the Young modulus FEA method to take in account the shear modulus, the poisson coefficients and the anisotropy of the material Glue film is not modeling but the level of the shear stress between honeycomb and the skins is relevant and must stay under the limit for the glue • As requested by Italian colleagues last week (see talks of Francesco and Stefano), we need to validate together the final protocol to qualify the material (additional test with larger samples?) MM Weekly meeting - 3rd of December 2013 CEA-Saclay/DSM/Irfu - Patrick PONSOT | PAGE 12
Qualification of the sandwiches and of their assembly First results have been presented by Fabien during the MM workshop on 5-6 th of November, here is the summary: Honeycombs Aluminum 5056 Nomex Foam material Comp. Distribution Dupont-Nemours Rohacell 4.8mm/0.05m 4.8mm/0.05mm --- 130kg/m3 48kg/m3 52kg/m3 Equivalent Young 24 8 ~5 modulus (Gpa) Shear stress for 27-48 20-32 11 the glue (Mpa) Comment on Breaking of the FR4 Breaking of the Breaking of the FR4 destroying and of the gluing gluing and of the gluing • 2 samples (Nomex) have been received from Roma and will be measured asap MM Weekly meeting - 3rd of December 2013 CEA-Saclay/DSM/Irfu - Patrick PONSOT | PAGE 13
Qualification of the sandwiches and of their assembly Applying of the qualification of the material with the testing of the 3 panels assembly (first result presented by Fabien during the MM workshop on 5-6 th of Nov.) • This 3 panels assembly has been done to study the transmission of the deformation of the outer panel to the inner panel through the interconnections (glued pillars in the drift gap, Nomex honeycomb) • 8 pillars are distributed on a panel 1.2mx0.6m (300mm between pillars in X-Y direction) • Measurements are done between the pillars, first with screwing assembly (sliding is possible), second with gluing of all the components Measurement with local loading in the Calculation with thermal loading middle of the panel +2°C on all the top side MM Weekly meeting - 3rd of December 2013 CEA-Saclay/DSM/Irfu - Patrick PONSOT | PAGE 14
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