1. projective Praxial =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

2. BOL and NIKHEF In-plane measures a lot. Most relevant: TORQUE (20urad) Can be studied in Cosmic ray stand (NOW, no global geometry needed) BIS 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)

3. 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!!!

4. 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

5. ASAP ROOT/C++ package Nominal geometry: AMDB database New Geometry from alignment + temp sensors Uses Muonbox or Moore Thinkable that this migrates to Athena

6. 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