ATLAS-NSW FRASCATI MMM workshop Saclay plan

Patrick PONSOT for the CEA-Saclay-Irfu group:

F.Bauer, P.Daniel-Thomas, E.Ferrer-Ribas, Ch.Flouzat, J.Galan, W.Gamache, A.Giganon, P-F.Giraud, P.Graffin, S.Herlant, S.Hervé, F.Jeanneau, H.LeProvost, O.Meunier, A.Peyaud, Ph.Schune

ATLAS-NSWFRASCATI MMM WORKSHOPSACLAY PLAN

29-30th of November 2012

Frascati MMM workshop - CEA-Saclay/DSM/Irfu - Patrick PONSOT

OUTLINE

2012/11/29-30 | 2

Design ideas• Saclay’s baseline / size of the wedges (quadruplets)• Possible mechanical design of a quadruplet• Dedicated frame to fix the mesh and the drift electrode• Positioning of the doublets• Alignable ?• Materials

Proposal to build an operational quadruplet• Learning about procedures (gluing, positioning,…etc.)• Checking all parameters (precision, in-plane alignment, electronics, RO mapping,

services…etc.)

Assembly ideas• Assembly procedure of the quadruplets (some remarks)• Assembly of the quadruplets to form a wedge, a station, a sector ?• In-plane alignment ?

Mechanical prototypes and task sharing• Objectives

- Control of the geometry (precision of the construction)- Control of the deformation (in-plane alignment)

• Behavior of a doublet (with and without pillars) ?• FEA - Thermo-mechanical simulations• Schedule and sharing of work


OUTLINE

2012/11/29-30 | 3



services…etc.)






INTRODUCTION

2012/11/29-30 | 4

A report has been written to describe the Saclay’s plan for the mechanical architecture of the micromegas wedges


DESIGN IDEAS

2012/11/29-30 | 5

Saclay’s baseline = 2 Wedges made of 4 Modules with maximum size ~2m2

• As reminder : MM Module = Quadruplet = 4 planes in Z direction

Why ?• We think that it is not possible to reach the perpendicular required

precision of the strips by assembly of 4 planes with a very large area (large sector ~6m2)

- In spite of a lot work, we never reached this range of precision during the construction of the ALICE muon panels (carbon fibers panels)

- Using our experience on CTA mirror (very recent tests), we think that we can reach the precision for a 2m2 area

At the end we need :• sMM < 100 mm (micro-TPC mode)• strip parallelism: ≤ 40 mm• Mechanical precision perpendicular to strip plane:

• <150 mm at 15° (inner quadruplets)• < 80 mm at 30° (outer quadruplets)

• Very complicated to realize the 2D read-out mapping and to connect the Y strips through the full length of the wedge (~3.7m)

Views on next slides


DESIGN IDEAS

2012/11/29-30 | 6

Saclay’s baseline = 2 Wedges made of 4 Modules with maximum size ~2m2

• As reminder : MM Module = Quadruplet = 4 planes in Z direction

Why ?• From our experience:

MM Compass(G10)

Alice / Carbon panels

MM T2K(G10)

CTA mirrors(Carbon, G10, Al.)


DESIGN IDEAS

2012/11/29-30 | 7

Possible mechanical design of a quadruplet (scheme)• Central panel is the mechanical support (thickness at least 20mm to define by FEA, and

to test with prototypes)

At l

east

~75

mm

At l

east

~20

mm

Fixation (and gluing?) of the mesh frame Possible to put an interface

to connect the supports

Assembly of the quadruplet after positioning of the 2 doublets Mechanical reference system to position

the 2 doublets (metallic inserts)

This part of the central panel can be local or all along the sector

If needed, pillars

Doublet

Doublet (Not

up

to d

ate)


DESIGN IDEAS

2012/11/29-30 | 8

Possible mechanical design of a quadruplet (scheme)• Supporting of 2 quadruplets, in-plane alignment system → Local links (to confirm by

FEA)

In plane alignment to connect the 2 quadruplets

Local supports~7

5mm

At l

east

~22

5mm

The 2 MM wedges are linked by local supports

(kinematic links)

Bar support to link the 4 modules

(Not

up

to d

ate)

(Not

up

to d

ate)


DESIGN IDEAS

2012/11/29-30 | 9

Possible mechanical design of a quadruplet (scheme)• Supporting of 2 quadruplets, in-plane alignment system → If local links are not enough,

by using a spacer-frame

In plane alignment to connect the 2 quadruplets

The 3 kinematics supports can be fixed on the spacer-frame

At l

east

~22

5mm

The 2 MM wedges are linked by a spacer-frame(kinematic links, holes to

have access to the electronic)

~75m

m(N

ot u

p to

dat

e)(N

ot u

p to

dat

e)


DESIGN IDEAS

2012/11/29-30 | 10

Possible mechanical design of a quadruplet (scheme)• Dedicated frame to fix the drift cathode and the mesh ?

• A transfer frame can be used for mounting

Fixation (and gluing?) of the mesh frame

Cathode made of kapton or mylar + Copper or al.

Mesh

Transfer frame to maintain the tension inside the mesh and cathode

(Not

up

to d

ate)


DESIGN IDEAS

2012/11/29-30 | 11

Possible mechanical design of a quadruplet (scheme)• Positioning of the 2 doublets• By using metallic inserts glued with high precision during the

construction of the doublets• Targets reference on PCBs to glue the inserts and to check the

alignment of the 2 doublets• Z positioning of the doublets is done also by using the inserts

(on doublets and on central panel, precise thickness)

Mechanical reference system to position the 2

doublets (metallic inserts)

Assembly of the quadruplet after

positioning of the 2 doublets

(Not

up

to d

ate)

DESIGN IDEAS

2012/11/29-30 | 12Frascati MMM workshop - CEA-Saclay/DSM/Irfu - Patrick PONSOT

Possible mechanical design of a quadruplet (scheme)• Alignable (in-plane alignment is on the outside panel) ?• How can we guaranty that the stiffness of the doublets is enough

to control the Z position of the strips inside a quadruplet (// of the doublets after deformation due to thermo-mechanical loading) ?

• Testing is needed to know the relative deformation of each panel inside a quadruplet

• If result is negative, pillars (or other spacer) should be glued in the drift gap (40 pillars diameter 5mm is less than 0.2% of the detection area)

• More difficult to glue the pillars with separate mesh (no bulk), and with separate drift cathode

If needed, pillars

5 m

m

Gluing on few additional and larger pillars ?

5 m

m// strips

No bulk

Bulk

Deformation with thermal loading is not symmetric

(Not

up

to d

ate)

DESIGN IDEAS

2012/11/29-30 | 13Frascati MMM workshop - CEA-Saclay/DSM/Irfu - Patrick PONSOT

Possible mechanical design of a quadruplet (scheme) → Materials• Honeycomb should be perforated (or porous) to use the vacuum pumping for gluing

Materials Mass density (g/cm3)

Young modulus(Gpa)

CTE(ppm/°C)

G10/FR4(Epoxy-glass) 1.9 ~17 10-20

Copper 8.9 ~120 16-17

Honeycomb (6mm) - “paper” ~0.032

Honeycomb (6mm) - aluminum (50µm perforated)

~0.040 ~76 23

Pyralux PC1025 (photoimagable film) tbd tbd (global test of PCBs) 100-130

• Tensile tests in 3 directions to evaluate the Young modulus of the PCBs has been done at Saclay

- L (length direction) → 24 Gpa- l (width direction) → 21 Gpa- p (45°) → 17 Gpa

• Very important parameter : ageing of the material should be studied before to use them (e.g. zebra connectors are made of silicon elastomer which has a bad withstand to radiation)


OUTLINE

2012/11/29-30 | 14



services…etc.)






PROPOSAL TO BUILD A QUADRUPLET

2012/11/29-30 | 15

Building an operational quadruplet (~1m x ~0.5m) within the collaboration• Not a critical milestone

• But necessary part of the Saclay’s development plan to prove to the CEA-Saclay-Irfu management team that the assembly of 4 MM planes will be completely understood before the construction of a module zero (to get resources to prepare the production)

Objectives• Learning about procedures (gluing, positioning,…etc.)

• Checking all parameters (precision, in-plane alignment, electronics, RO mapping, services…etc.)

• Testing inside a precise cosmic bench


PROPOSAL TO BUILD A QUADRUPLET

2012/11/29-30 | 16

Building an operational quadruplet (~1m x ~0,5m) within the collaboration• Not a critical milestone

This prototype will allow checking of the:

• design and manufacturing of the components• assembly procedure• mechanical precision• in-plane alignment method• 2D read-out mapping• electronics implementation• cosmic tests• services (HV, gas, …)• …

To be discussed within the collaboration:

• Tasks sharing within the collaboration• Parallel testing ?• Using of existing precise cosmic bench


OUTLINE

2012/11/29-30 | 17



services…etc.)






ASSEMBLY IDEAS

2012/11/29-30 | 18

Assembly procedure of the quadruplets (some remarks)• Due to experience of the institutes, we think that it is accessible to define precise

tooling and procedures to build and to align the components but we will use a new material → large PCBs made of composite materials: G10, pyralux, copper…etc.

• Gluing procedure by using vacuum should be tested with real PCBs as soon as possible to answer to the following questions :

- What is the best choice for materials to control the geometry during the production (stability, reproducibility) ?

- Will the PCBs follow the granite table flatness ?

- Will the PCBs stay flat after gluing of the honeycomb (temperature and humidity inside the cleaning room to do the gluing) ?

- Do we get the // for the doublets by using the stiffback ?


ASSEMBLY IDEAS

2012/11/29-30 | 19

Assembly procedure of the quadruplets or wedges (some remarks)• A preliminary study has been done to evaluate the infrastructures and tooling that is

needed to build quadruplets• The building of the second ring of quadruplets has been used as main hypothesis to

do this study• We need a large cleaning room to do all the steps (2 gluing tables, 3 assembly

tables)• Unfortunately, the Saclay’s cleaning rooms are not available on 2013-2014. And

we are not sure to get a new one. The construction of the operational quadruplet prototype will influence also the final decision

• We need one year to create a new cleaning room• It is very important to take in account the infrastructures that we need to define the

size of the modules that we can build (wedges ~6m2 or quadruplets ~2m2)• May be the assembly should be done at CERN in a large cleaning room with

participation of institutes

Preliminary study to define a new infrastructure


ASSEMBLY IDEAS

2012/11/29-30 | 20

Assembly of quadruplets to form a wedge, a station, a sector ?• MM Wedges vs MM quadruplets• sTGC wedges can be added with the same principle

3 kinematic supports to fixe the 2 wedges

3 kinematic supports to fixe the spacer-frame

~5.87m2

~1.89 m2

~1.85 m2

~1.33 m2

~0.80 m2


ASSEMBLY IDEAS

2012/11/29-30 | 21

In-plane alignment system• To be defined with specialists• In-plane with 2 functions (to follow the 2 wedges)

3 kinematic supports to fixe the 2 wedges

3 kinematic supports to fixe the spacer-frame


OUTLINE

2012/11/29-30 | 22



services…etc.)






MECHANICAL PROTOTYPES

2012/11/29-30 | 23

Objectives• Control of the geometry (precision of the construction)• Control of the deformation (to define the in-plane alignment)

Study of the geometry of a doublet• Stiffness of the composite panel (PCBs + honeycombs + frames)• Gluing test of 2 PCBs on the honeycomb (vacuum)• Using of a composite stiffback

• Saclay’s plan:- Gluing of honeycomb on standard PCBs to evaluate the stiffness of a support panel- Gluing of honeycomb on large MM PCBs (paper honeycomb, perforated aluminum

honeycomb…etc.)

• Options:- Sharing of the tasks and parallel testing with real PCBs (bulk & no bulk ?)



2012/11/29-30 | 24

Study of the deformation of a quadruplet• FEA to predict the deformations: to choose the size of the mechanical prototype• Measurement without and with pillars• Mechanical and thermal loadings

• Saclay’s plan:- Construction of mechanical structure equivalent to a MM doublet (G10 + honeycomb)- Dismountable to test without and with pillars- Holes in the external panels allow mechanical measurements on the central panel- Assembly with and without expandable pins to study the effect of the sliding of the

frames

• Options:- To build an equivalent quadruplet (5 panels)- To build an assembly of 2 doublets (2x3 panels)- To use other materials (e.g. aluminum honeycomb, PCBs…etc.)


Study of the gluing of pillars• Qualification of the gluing• Choice of material for the pillars (Macor, peek…)

• Saclay’s plan:- Tooling is under manufacturing- 200 pillars have been ordered (Macor,

peek, different geometry to put the glue)

• Options:- Testing of other solutions and materials to

guarantee a similar behavior of each MM plane after stacking


2012/11/29-30 | 25



2012/11/29-30 | 26

Study of the positioning inside a quadruplet• As described on slide 11 (positioning of the 2 doublets)

• Saclay’s plan:- Building of a simplified quadruplet (e.g. with the doublets created during other

tests)

• Options:- Parallel testing- Other solution such as optical systems

sTGC proposal


THERMO-MECHANICAL SIMULATIONS

2012/11/29-30 | 27

FEA analysis• Preliminary FEA analysis have been done to:

- provide arguments in order to make a decision concerning the layout- Identify the main cause of irregular deformation → thermal loading

• We need engineering models to:- Confirm that we can control the geometry with the alignment system according to

the different options (quadruplets, wedges, stations, sectors…)

Thermal expansion MM+sTGC

~100µm

Temperature gradient 2°C

~50µm


THERMO-MECHANICAL SIMULATIONS

2012/11/29-30 | 28

FEA analysis• Preliminary study of the behavior of a mixed sector (sTGC wedges + MM quadruplets fixed on a

spacer frame) w.r.t. the position on the small wheel• In this case, MM deformation is around ~100µm

Vertical sector

Horizontal sector

Sector at 45°

If we are not able to measure this type of deformation with the alignment system,

we must guaranty that we will stay under these 100µm


SCHEDULE AND SHARING OF WORK

2012/11/29-30 | 29

Preliminary schedule• Help from collaboration is needed and is welcome : Task and cost sharing• To participate to this program and/or to complete it


CONCLUSION

2012/11/29-30 | 30

Sharing of work and parallel testing within the collaboration are welcome to cover this plan as soon as possible• Mechanical tests• FEA analysis• Operational quadruplet• In-plane alignment

Assembly of the quadruplets or wedges• The largest cleaning rooms at Saclay will not be available on 2013-2014• The possibility to use a cleaning room at CERN should be evaluate


DSMIrfuSIS/LCAP (PC N°12, Bt 123)Patrick PONSOT

Commissariat à l’énergie atomique et aux énergies alternativesCentre de Saclay | 91191 Gif-sur-Yvette CedexT. +33 (0)1 69 08 79 30 | F. +33 (0)1 69 08 89 47

Etablissement public à caractère industriel et commercial | RCS Paris B 775 685 0192012/11/29-30

Thank you for your attention !

| PAGE 31

ATLAS-NSW FRASCATI MMM workshop Saclay plan

Documents

Transcript of ATLAS-NSW FRASCATI MMM workshop Saclay plan