20.03.2012 T. Kawamoto 1
Recommendation for the New Small Wheel
layout
T. Kawamoto (NSW i-project leader),J. Dubbert (NSW i-technical coordinator),
L. Pontecorvo (Muon PL), S. Vlachos (Muon deputy PL),
NSW review panelM. Nessi, P. Farthouat, A. Romaniuk, F. Lanni, N. Konstantinidis
Muon week, NSW workshop20.03.2012
20.03.2012 T. Kawamoto 2
Motivation for NSW : the two pillars
Kill the background L1 in endcap (=1.3 – 2.5) and reduce the rate by factor ~6
Ensure precision tracking up to the ultimate Lumi (7x1034) with a comfortable safety margin
On-line re
constructio
n
of track segments,
1 mrad re
solution
L1MU20 distribution
Rate vs R in SW
necessary step for further upgrade:phase-2
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History
• Many years of R&D on the possible technologies for the NSW– sMDT: 1/2 diameter of MDT tubes to gain factor 7 in rate
capabilities. Proposed for tracking– sTGC: Read out strips of 3mm with a T over Thr technique
to reach 100 m resolution usable also for triggering, very good rate capabilities proposed for triggering and tracking
– Small gap RPC: sub ns time resolution and 300 m space resolution, rate capabilities increased by >10 with thin gap and new front end electronics, proposed for triggering
– Micromegas: very good space resolution, very high rate capabilities, very promising new technology, proposed for triggering and tracking
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History
• A lot of very interesting results and improvements on both new and “old” technologies has been achieved and presented in the upgrade meetings.
• Last year – Tatsuo Kawamoto was elected Project Leader of the new Small Wheel – to move from the R&D phase to the definition of the project– Defined the timeline for this transition: first months of 2012.– A panel was formed in summer 2011 with the mandate of helping us
in defining the NSW technology.• A. Romaniuk, F. Lanni, P. Farthuat , N. Kostantinidis and M. Nessi.• Huge work done by the panel together with the proponents of the
technologies in a very open and constructive spirit.• Many Thanks from our side to them. It was a real pleasure to work with them.
• 26-27 January 2012 meeting in Le Brassus where the ideas and the questions of the panel on the different technologies were presented and a lot of discussions took place.
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History
• Few weeks later we converged to two proposals, which were circulated in the community for evaluation
• The community at large has been asked to report their ideas on both proposals, and their willingness to participate to the NSW project regardless of the chosen scheme and their initial field of interest.– Many discussions with institute leaders and people interested in the
project.– Again with very open and collaborative spirit.
• The community ended up split almost exactly in two, but the overwhelming majority declared that they would happily work also on their second choice.
• The Panel, the muon and the NSW management had a series of meetings among them, with very deep discussions on both pros and cons of the proposed solutions.
• Friday 16 March the NSW and the Muon management, in agreement with the Panel, decided to recommend to the community a single solution.
20.03.2012 T. Kawamoto 6
Next steps
• This meeting: • mainly to assess the consensus of the community on the
proposed solution • Thursday at the Muon IB:
• the NSW and muon management will ask for Endorsement on this recommendation.
– P.S. The Muon IB cannot decide on items that are relevant for the full collaboration, but can give endorsement to the proposal
– The ATLAS CB will vote to give the final approval.
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Two proposals
•Homogeneous: sTGC + Micromegas•Possible full redundancy for trigger and tracking.•Featuring high rate capabilities and space resolution on both detectors
•Split: sTGC for triggering, MM (small R) and sMDT (large R) for tracking. •Featuring larger safety margins in case of problems with MM technology
sTGCMMsMDT
Homogeneous Split
chamber segmentation in R
and order along z are preliminary
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Two proposals
• sTGC is used in both options for triggering and tracking– Pros:
• sTGC construction can start very soon, proven technology• Adequate time resolution for BC identification• Adequate space resolution for trigger and tracking
– Cons:• sTGC internal and external alignment concept has to be
studied• Limited number of institutes interested in the production
and operation of this detector (Need to be reinforced).
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Two proposals
• Why the RPC was not further considered– Main feature of RPC is the sub-ns time resolution
• It is clear that this can give a very large fake rate reduction• We acknowledge it, but we think that the same reduction can be
achieved also using other means (granularity, space resolution+ moderate time resolution)
• The space resolution presented was of about 300 m, not demonstrated on-line at the moment
• We consider it sufficient for the trigger, but has to be demonstrated on-line and moreover it is by far not sufficient to complement the tracking, sTGC on the other hand have this possibility with a moderate time resolution.
• The presented project is considered not very clear and advanced, we acknowledge that we received lately an addendum with clarification and new information.
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Two proposals
Homogeneous : Pros
– Fully redundant:• Both TGC and MM can be used in the trigger system allowing a very
robust and flexible trigger even in the presence of very unexpected backgrounds or detector failures.
• Both detectors can be used in the tracking with adequate intrinsic space resolution.
– Very robust pattern recognition and tracking with as much as 16 space points (3d) per track.
– Excellent Rate Capabilities for both detectors– Very large safety margins on cavern background possible.
– Very good two track separation (MM) and pattern recognition capabilities – Simpler service distribution (2 technologies) – Large community interested in development of Micromegas also for
future use in ATLAS
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Two proposals
Homogeneous : Cons
– Extensive R&D required for proving feasibility and industrialization of of large sized MM
– TPC operations for large angle tracks to be demonstrated, change in reconstruction method as a function of track angle.
– Both internal alignment and global alignment concepts have to be developed (cf. sMDT).
– Large number of channels – More “risky” solution, implying the use of new detectors within a fixed
schedule (no LHC delays this time)
20.03.2012 T. Kawamoto 12
Two proposals
Split : Pros
– sMDT is a well proven technology, adequate for a large part of the NSW acceptance (but possible issues for unexpected background at large eta).
– No more R&D required on sMDT and production can start very soon.– Alignment concept already developed for sMDT (not for MM as in the
previous solution)– MM of CSC like dimension can be built very soon and the industrialization
process can start sooner. Moreover if any problem in the MM construction/operation is encountered a fall back with full sMDT can be envisaged even quite late in time (Fail safe solution)
– Production of sMDT ensure the formation of new experts to maintain not only the NSW but the full detector.
– The sMDT offline reconstruction is almost identical to the one used now. Readiness for the first collisions in 2018 (at least for the sMDT part).
– The sMDT can be used as demonstrator for the use of MDT in the trigger necessary in phase 2 on the Big Wheel and barrel.
20.03.2012 T. Kawamoto 13
Two proposals
Split : Cons
– Complexity in the construction and surface commissioning: 3 systems– More complex service distribution– Rim will be full of on-detector electronics– The R&D needed on some technologies is similar in the two approaches.– Different algorithms for track reconstruction as a function of the incident
point in the NSW (MDT – MM).
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Two proposals
• Common comments in favour of Homogeneous
– Full redundancy especially for the trigger (not present in the Split solution)
– Better performance in terms of resolution and rate capabilities– Simplicity in commissioning, operation, services etc.
• Common comments in favour of Split
– Best option where the strength of each technology is used effectively. Given the short amount of time it is also the most realistic solution with the lower risk.
– Potential of creating new experts for future maintenance of MDT and TGC of the full detector
– Ready to reconstruct tracks (at least the sMDT part) from day 1 of LHC
Response of the community
NOT Responding yet
Community split in half
Large majority interested in contribution to the upgrade even if their preferred solution is not chosen: about 80%
Homogeneous Solution Cost
• CORE cost. No overhead for manpower, R/D etc• Approximate Budget based on input from proponents• Common cost for F/E electronics• Trigger electronics not included• Rough estimation of installation etc cost
• Budget : 10700 KCHF– sTGC : 2300– MM : 6000– Common : 2300
20.03.2012 16T. Kawamoto
Split Solution Cost• In addition to previous:• Fixed costs kept as before• Variable costs scaled to size/number of channels• Rough estimate of overhead for three technologies
installation
• Budget : 10100 KCHF– sTGC : 2300– MM : 2800– sMDT : 2300– Common : 2600
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The cost for the two options is
~ equal
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The single solution to recommend
• We recommend to adopt the Homogeneous solution for the following main reasons:– Redundancy in both trigger and tracking,
especially on trigger– Strength of the community behind Micromegas
that mitigate the worries on the R&D still needed– Simpler solution in terms of number of
technologies and services distribution.– Development of a new powerful technology also
for other possible uses in the future of ATLAS.
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Additional remark
We consider both sMDT and mRPC to be very important technologies for further upgrade of the muon spectrometer, for examples:
• Inner BW region• Transition region (trigger and tracking) EIL4, BIS7,8, EE, BEE• Gaps of acceptance• Improving the trigger pT resolution (barrel and endcap)
and therefore in the strongest way to support their further development.
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A few parameters of the homogeneous solution
Number of chambers Number of layersNumber of readout channelsNumber of trigger channelsNumber of fibre links
128 8400K 64K(*)800(*)
128 8 2M 31K2000
sTGC MM
* nr of pads* trigger signals
2018201720162015201420132012
commissioning
installation
JD-nSW integration
removal old
nSW assembly + system testsintegration and commissioning at CERN
chambers / electr. construction
module 0 qualified in beams
Module 0 construction
approval/organize resources
TDR
Design & gen R&D
support structure construction
Time line
An
idea
to s
ee if
all
fit
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Critical milestones
• Form a simulation group by mid 2012.• Construction of a few MM chambers (4 planes), of max size
achievable at the moment, in next 3 months, and tested at H6.• Production and test of a full size prototype for both technologies by
beg. 2013.• Qualification of the FE electronics (BNL chip) by fall 2012.• Demonstration of the MM spatial resolution with mTPC by fall 2012.• Demonstrator of the trigger concept by mid 2013.• Results on ageing and performance under irradiation by end 2013.• Test of triggering capability under irradiation by end 2013.• Precision of mechanical assembly by mid 2012.• Precision of the mechanical assembly (including strips precision and
internal alignment) : a system test, by mid 2014.• Qualification of components prior to start of production.
Draft
20.03.2012 T. Kawamoto 23
How to organize the project
• Consortia:– Detector construction and integration
• Sites, groups– Alignment (work together with detector mechanical design)– Production Quality assurance – Detector Control system– System integration (mechanics, services, cooling, …)– Front end electronics– Trigger front end electronics– Trigger backend electronics– Readout system– Software
• Simulation • Reconstruction
Starting the even more difficult part
Consortia concept (first idea) (chambers technology is not the end of the story)
Chambers technologis
Mechanical structure, alignment, …
Back-end, RODs, Online software, controls, services, power
LVL1 Trigger Electronics
Front-end electronics
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Next steps
• Collaboration formation• iMoU• TDR• Real work
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Back up
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LHC and ATLAS upgrade∫ L
dt
Year
phase-0
phase-1
phase-2
2013/14 2018 ~2022
7 TeV →14 TeV
1027 →2x1033cm-2s-1
→ 1x1034cm-2s-1
1x1034 →~2x1034cm-2s-1
Now
~10 fb-1
~50 fb-1
~300 fb-1
3000 fb-1
→ 5x1034cm-2s-1
luminosity leveling
Possible upgrade timeline
• new shielding winter 2011-12
• elevator hole chambers• trigger in barrel feet region
•New small wheel
•And more
Integrating small wheel TGC in Endcap L1 : update SL programing
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Phase-1 upgrade : the new small wheel
Protons : tracks and their birth position
FLUGG simulation, no cut on p
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Phase-1 upgrade : the new small wheel
coilcryostat
Unshieldedbeam pipe
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K. Nagano
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NSW spec is designed for further upgrade
NSW primary goal : to remove fakes.
Designed also for improving pT of L1
• size of luminous region 1-2 mrad• multiple scattering in the calorimeter 2-3 mrad• multiple scattering in the EC toroid 1 mrad• angular resolution of BW 3 mrad
measure and correctwith NSW: need 1 mrad resolution
upgrade of BW (phase-2)
nominal threshold
pT after fake removal with NSW
20.03.2012 T. Kawamoto 32
Trigger and tracking improved byNSW
What about other region?
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What about other region?
Not covered by NSW. Something else is needed.
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What about other region?
Implementation into the trigger is planed at phase-0 upgrade (201 ３ /2014)
•Find wire/strip hits in a same chamber
•Geometrical matching between BW RoI and TGC-inner.
Emulation of trigger with TGC-InnerEmulation of trigger with TGC-Inner
Reduction for “L1 MU11” 81.0%Eff. for offline Pt>MU10 98.6%
TGC-EI: 1.02<|η|<1.24TGC-FI: 1.23<|η|<1.88
η coverage of TGC-inner
Something that can be done before NSWusing existing detectors
TGC (doublets) on EI (small wheel, EIL4),currently not used for L1
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Phase-2 ideas and more
•Barrel L1 upgrade (using MDT) : better pT resolution •Further L1 upgrade in endcap (using also MDT to improve big wheel): better pT
•New trigger chambers for barrel-endcap overlap region.
Profiting from longer L1 latency
