dt upgrade strategy

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DT UPGRADE STRATEGY

M.Dallavalle for the DT Collaboration

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• The DT plan for the future started in 2009

• It covers from 2013 up to LS3• Physics target: warrant the

same excellent performance while LHC “grows” up

• LS1 2013 is the first step of a long-term strategy

• Improve robustness and longevity

• Improve flexibility to adapt to new conditions and to exploit new possibilites

» In particular for the TRIGGER

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• Learn from Today’s system: what & why improve

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Nowadays: System overview

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Sector collector

TRBs

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Studies with single-hits show that the tubes can stand the LHC environment

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Aging of Minicrate electronics

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• On-chamber Minicrates contain TDCs and trigger ASICs. BTIs date back to mid 1990s. Boards have been tested for at-least 10 years of LHC at 10^34 Hz/cm2.

• BTIM of Trigger Boards contain 4 BTI dies: bonds are sensitive to thermal stress during switch on/off. Current stock of spares is a potential issue.

• Conclusion: Minicrates can survive until LS3 provided we reinforce our stock of BTIMs

6DTTF

*BTIM functionality ported to rad-hard FPGA and new THETA TRB being produced. These will replace the old THETA TRBs in MB1 and MB2 of the external wheels (+2,-2)* Cannibalize retrieved BTIM for reparation of PHI TRBs

C. F. Bedoya May 22nd, 2012 6

Trigger in the theta view

BTIM technology obsolete=> migrate to FPGA

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Minicrates in LS3

• The electronics will be 30 years old• It has been designed for using HDL and

the functionality can be transported to New more performing technologies

– See theta TRB replacement as an example

• However, the connections of Minicrates and the other system boxes constitute a bottleneck of the system: change to optical fibers as much as possible

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Sector Collector limitations • In particular, the flow of Minicrate data

goes through the Sector Collectors (one per wheel) in the detector towers and this is a limit to the connectivity of the minicrates and constitute potential single failure points, given the limited access to UXC

• Move the SC to USC: connect all Minicrates to USC with optical fibers

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System overview after LS1

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New TSC

2016-2017?UXC USC

Sector collector

DTTF

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New opportunities with all chamber trigger data in USC

• The optical fibers from the Minicrates can be split and offer input for running a new system in parallel to the current.

• At trigger level can test new algorithms exploiting single chamber (or even single Super-Layer) triggers in the difficult regions

• Can study new algorithms to improve redundancy with RPC (also available on fibers in USC).

• DT/RPC coincidence at station level can improve the BX ID in situations of high PU

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Trigger Track finding limitations• The track finding algorithm requires trigger

segments from at least 2 chambers along a muon track

• This is a problem at eta +0.25,-0.25, i.e. in the cracks between wheel 0 and wheel +1,-1

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Inefficiency btwn YB0 andYB+1,-1

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another crack: The overlap region

Perchaps coincidence of signals from single DT, CSC, RPC chambers can be exploited for improving the efficiency in difficult regions

Trigger logics memo:

• CSCTF >= 3 CSC

• DTTF >= 2 DTs

• RPC 3of4 or 4of6 RPC

• Overlap DT&CSC, RPC not used

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Muon Pt assignment in trigger

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LV1HLT: Full TDC data;Standalone muon system;limited by multiple scatteringHLT: tracker + mu ID will allow trigger thresholds =< 20 GeV

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DTTF Xsec (μb)

DTTF η<0.8DTTF η<1.2

0.001

0.01

0.1

1

(Courtesy of C. Battilana (CIEMAT) )

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LV1 Track finder with Muon + tracker• extract selected tracker information and

combine it with the muon system in order to produce a muon trigger at Level-1

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• after SC relocation, some PIXEL information (outer layer preferentially) could already be used, if available, in 2017

• Keep independence of the new tracker design. Define Region-of-Interest

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R.o.I. for muon track• Different possibilities:

– The RoI can be defined by the muon system at a pre-Lv1 stage so that the load of data transfer from the tracker is reduced. This probably needs a new fast detector underneath MB1 stations with very rough (10-25 cm) position determination (MTT (CMS IN-2007/058), Y.Erdogan’s talk at this morning’s DT upgrade session,)

– The RoI can be defined at the Regional Level, using the DT trigger primitives to search the full tracker data (P.L.Zotto, DT part in upgrade Technical Proposal)

– The RoI can be defined by the tracker searching in the muon primitives a matching segment to a tracker stub (with tracker pt above threshold)

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DT ugrade strategy in short

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PHASE 1 LS1 (2013-2014)• Replacement of theta TRB (Trigger boards) : new TRBs use FPGAs; recuperate

BTIMs as spares for R-phi TRBs

* Relocation of Sector Collector from the cavern (UXC) to the counting room (USC): optical fibers to bring TDC data and trigger primitives from all chambers in USC

PHASE 1 following steps (not strictly related to LHC shutdowns) (2015-2017):Exploit optical fibers bringing all chamber (trigger) data in USC for running also a concurrent system for track finding (may also use RPC, pixel?, …)* Replacement of DTTF (DT Track Finder) * Redesign of the TSC boards (Sector Collector trigger)* Redesign of the ROS boards (Sector Collector read-out)

PHASE 2 (LS3) (2018 and beyond)* Insert connection with the tracker in the Level-1 trigger system (RoI)* Replacement of Minicrate electronics??

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Conclusions

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…possibly….