1. ATLAS micromegas activities (MAMMA)
Status report
RD51 mini week, 14/06/2012
Joerg Wotschack (CERN)

2. The status of the ATLAS New Small Wheel project
Beginning of May the ATLAS Muon IB endorsed the baseline for the instrumentation of the New Small Wheel as proposed by the muon management, it consists of
2 x 4 layers of sTGC detectors, mainly for triggering (but also tracking)
2 x 4 layers of Micromegas, mainly for precision measurement (but also triggering)
The decision was taken subject to a number of milestones to be fulfilled by both technologies by the end of 2012; the main ones for the MMs are
Show that 2 x 1 m2 micromegas can be built with the required precision
Demonstrate that a resolution of <100 µm can be achieved for inclined tracks
Performance in magnetic field (see talk by G. Iakovidis in WG2)
Ageing under sparking (see talk by J. Galan in WG2)
Since then a number of new institutes have joined MAMMA
RD51 mini week, 14/06/2012
Joerg Wotschack (CERN)

3. ATLAS Small Wheel upgrade
Baseline solution
Equip the Small Wheels with sTGC & micromegas chambers
sTGC as trigger chambers
MM for precision and 2nd coord. Measurement, as well as trigger
Each MM comprises eight active layers, arranged in two multilayers, separated by 10 cm
Each layer with two coordinates with 0.5 and 1.5 mm strip pitch (or stereo)
2M readout channels
a total of about 1200 m2 of detection layers
2.4 m
Present Small Wheel
RD51 mini week, 14/06/2012
Joerg Wotschack (CERN)

4. New Small Wheel Layout (under study)
RD51 mini week, 14/06/2012
Joerg Wotschack (CERN)

5. The ATLAS New Small Wheel project
The next steps (ATLAS procedures)
Initial design review (29 and 30 August)
Institute Kick off meeting (31 of August)
EB approval (14 September)
CB approval (5 October)
TDR & presentation to RBB in spring 2013
Chamber production
Working group has been set up in ATLAS to agree on a layout
Setting up a structure in MAMMA to follow production issues
Industrialization has started with a number of companies in Europe in the context (and with the help) of RD51, but also in the USA and Japan
Module 0 construction in 2013/14
Chamber production (1200 m2 of MMs) in 2015/16
RD51 mini week, 14/06/2012
Joerg Wotschack (CERN)

6. Other ongoing activities
MMs installed in ATLAS detector (Feb. 2012)
Four 10 x 10 cm2 MMs on ATLAS Small Wheel
One 9 x 4.5 cm2 chamber with two readout gaps (and two coordinates per gap) in front of EM calorimeter (very high rates ≥ 100 kHz/cm2)
Chambers are equipped with APV25 hybrid cards and read out through the RD51 SRS
operated flawlessly, (so far) in stand-alone mode with random triggers to study background
Integration into ATLAS DAQ and into offline analysis chain is ongoing (see talk by M. Byszewski and A. Zibell in WG5); expected to be operational in summer
RD51 mini week, 14/06/2012
Joerg Wotschack (CERN)

7. Joerg Wotschack (CERN)
ATLAS MBT0 chambers
Micromegas current (µA)
MBT0 detector installed on front-face of LAr calorimeter cryostat at 1 m from beam pipe
Typical interaction rate: ≈100 kHz/cm2
RD51 mini week, 14/06/2012
Joerg Wotschack (CERN)

8. Joerg Wotschack (CERN)
MMs on the Small Wheel
Stack of 4 micromegas chambers R19 (xuv), R18 (xy), R16 (xy), R13 (x)
Stack of 4 micromegas chambers installed on ATLAS Small Wheel A, sector 9
RD51 mini week, 14/06/2012
Joerg Wotschack (CERN)

9. Test beam activities in 2012
H2: 2–11 June
Study of performance of MMs in magnetic field, very successful (see talk by G. Iakovidis in WG2)
H6: 25 July – 8 Aug. and 1 – 6 Nov.
Eight 10 x 10 cm2 MMs & new BNL front-end chip (VMM1), see talk by V. Polychronakos in WG5
Demonstration of tracking precision for large angle tracks (µTPC mode)
Demonstration of trigger scheme (1 mrad track angle online)
1 x 1 m2 chamber with floating mesh and long strips
RD51 mini week, 14/06/2012
Joerg Wotschack (CERN)

10. Construction plans for 2012
Production of 1 x 1 m2 MM, made of two PCBs (0.5 x 1.2 m2) on common Al carrier, floating mesh (not bulk); to be evaluated in July test beam
Four planes of 1 x 2 m2 in bulk technology by the end of 2012 with the required precision (THE milestone !!!)
Various mechanical studies of PCB assembly to reach the required precision of 40 µm on strip location and flatness, as well as the relative alignment of several MM layers
RD51 mini week, 14/06/2012
Joerg Wotschack (CERN)

11. Joerg Wotschack (CERN)
Conclusions
Micromegas have been chosen as baseline for the precision measurement detectors (but also trigger) of the New Small Wheel of ATLAS, subject to some milestones
Most important milestone to be reached by end of 2012 is the demonstration that 2 x 1 m2 MMs can be built
Rich test programme, in particular using the new BNL VMM1 chip
Micromegas installed in ATLAS working flawlessly even at rates of 100 kHz/cm2; integration into ATLAS readout expected for this summer
RD51 mini week, 14/06/2012
Joerg Wotschack (CERN)