projectivePraxial=Proximity+Axial

In-plane

bil

bml

bol

Muon Chamber Alignment (Saclay)goal: absolute 30um on sagitta

sofar: relative movements (better 30um)

Can we contribute?ALIGNMENT=In-Plane + Praxial + Projective

BOL and NIKHEF

In-plane measures a lot.

Most relevant: TORQUE (20urad)

Can be studied inCosmic ray stand (NOW, no global geometry needed)

BISBIS

BOL (NIKHEF) 20um accurate, achieved!In-Plane x,y, scale, rotZ calibration to 20um effective (done, no direct proof)

In addition: platforms for praxial and projective aligment glued (using Saclay tools)

Datcha@NIKHEF

•Vertical alignment rays on praxial platforms

•In-Plane Torque can be measured between chamber pairs

•Projective platforms are not tested here (nor elsewhere), which limits the ‘power’ of this setup wrt alignment!!!

A quick fit• Tracking with Cosray (efficiency, resolution + many

studies needed, for example Tmax)• In-Plane (Torque) study• A few 100um check of praxial platforms + track

sagitta’s (we have some ideas….)• Basic relative movements: possible, but done

already years ago.• Get parameters out to tune ATLAS software!

If we go for more: ASAP needed

ASAP

• ROOT/C++ package• Nominal geometry:

AMDB database• New Geometry from

alignment + temp sensors

• Uses Muonbox or Moore

• Thinkable that this migrates to Athena

A ‘Quick-fit’ vs ASAP• Alignment=In-Plane+Praxial+Projective. Even with

ASAP projective is not measured. So….• ASAP is/was used in H8 Saclay responsibility.

Why do it here?• Unlogical to go for alignment software, while we

have experience with tracking reconstruction software. Get that in first.

• Why use ASAP for stand at nikhef. Do it completely independently for H8 and get prepared for ATLAS!!!

• Enough interesting stuff to do in cosmic ray stand without ASAP.

• Get parameters out to tune ATLAS alignment software. Let Saclay develop this software.

Note: this is my opinion + some statements to get discussion going