1. ATLAS Upgrade R&D and Plans
Su Dong
July 7, 2008
SLAC Annual Program Review

2. Meeting the Challenge of superLHC
Luminosity 1034->1035 gives ~40% higher effective energy reach for new physics
2013: Pixel b-layer replacement
: Improved L1 Trigger
2016 superLHC:
New Si tracker for SLHC
Trigger DAQ upgrade
LAr and Muon upgrades
Intense radiation environment: ~2x1016 P/cm2 at R=4cm
Dramatic pileup background: ~400 interactions/crossing
July 7, 2008
SLAC Annual Program Review

3. SLAC Involvement in superLHC Upgrade
superLHC is probably an inevitable path for HEP:
Early discoveries would imply the effective extra energy reach at high lumi could uncover additional new particles. Given the present investment, SLAC should continue to sLHC, with complementary physics to Linear Collider.
If early phase of LHC not revealing new physics, it would be hard to argue for ILC as is or other new facilities. sLHC will be taking on an even central focus of hope for new physics through its effective additional energy reach.
The time to be involved is Now. Schedule for upgrade design and construction is already not optimistic. With the end of B-factory operation and launch of GLAST, this becomes a natural interest among many staff members.
The upgrade activities at SLAC will be a key addition to better utilize the SLAC resources and expertise to complement current ATLAS efforts. The joint activities of physics, operations and upgrade will combine to a role appropriate for a national lab and encourage growth of user presence at SLAC.
Important detector training ground for postdocs and students.
July 7, 2008
SLAC Annual Program Review

4. sLHC Tracker Upgrade: Introduction
The entire inner detector of pixel+SCT+TRT will be replaced with an all silicon tracking system for sLHC:
Inner most pixel layer(s) need new sensor technology
Outer tracking with short and long silicon strips
Increased granularity for higher particle density demands new approaches to cooling, power deliver, data transmission.
Aiming at lower material budget.
SLAC has silicon experience from MK-II, SLD (pixel), GLAST and future silicon detector design of SiD.
Long
strip
Short strip
Pixel
(from a early SLAC study of strawman07 layout)
July 7, 2008
SLAC Annual Program Review

5. Tracker Upgrade: 3D Sensor for pixel
3D Sensor technology pioneered by Sherwood
Parker et al is a primary candidate for inner
most pixel layer:
Radiation hardness
Active Edge
The 3D R&D devices are produced at the
Stanford Center of Integrated Systems. Future ATLAS 3D sensors designs are also expected to have test samples from Stanford first for testing before production at SINTEF.
SLAC is participating in the Jun-Jul/08 3D beam test at CERN, and performing 3D sensor simulation.
SLAC is developing upgrade pixel teststand with compatibility to current and future ATLAS pixel readout electronics. Ideally located for first testing of 3D devices from Stanford.
Preparing proposal to join the 3D sensor collaboration.
July 7, 2008
SLAC Annual Program Review

6. Tracker Upgrade: CO2 Cooling (I)
The commissioning of the current evaporative C3F8 cooling system has been a rather difficult experience. Cooling becomes a central focus for the larger and higher granularity silicon system for sLHC with bigger challenge to avoid thermal runaway.
CO2 cooling is widely perceived as a better alternative to the current C3F8 cooling system and already chosen as baseline for strip detector upgrade. High latent heat and high heat and high vapor pressure allow efficient heat transfer with smaller pipes for reduced material. Also a more environment friendly solution.
Despite the priority and broad interests, very little has happened on CO2 cooling. More practical for a national lab.
SLAC engineer Marco Oriunno visited NIKHEF, CERN LHCb CO2 cooling system to engage in cooling system design for ATLAS.
CO2 cooling is also the new trend in industry and synergy with particle-astro applications.
July 7, 2008
SLAC Annual Program Review

7. Tracker Upgrade: CO2 Cooling (II)
SLAC’s plan for CO2 cooling involvement:
Step 1: Build an open loop small refrigeration system to study basic design features
Step 2: Serve the detector mechanical prototype cooling tests to iterate on design choices for piping/fitting and the overall system.
Step 3: A small pilot cooling plant at SLAC to serve stave tests and develop/validate the overall cooling system design.
SLAC is geographically well situated between LBNL and Santa Cruz as a center for the various cooling related tests for both pixel and strip detectors.
It’s a natural gateway to broader involvement in mechanical system designs.
July 7, 2008
SLAC Annual Program Review

8. Tracker Upgrade: Data Transmission
The high hit density and high radiation at sLHC poses new challenges to data transmission.
Current pixel optical data transmission elements will not survive sLHC radiation dose, and even more difficult to work for the colder operating temperature of -350C expected from CO2 cooling.
SLAC is leading the alternative technology R&D with multi-Gb/s electrical transmission through microCoax cables. Already demonstrated 4Gb/s on a rad-hard microCoax with bit error tests on FPGA test boards.
Doing radiation tests on better dielectric sample to validate a custom design with more favorable material budget and even better transmission bandwidth.
=> See Martin Kocian’s breakout session talk for details.
July 7, 2008
SLAC Annual Program Review

9. Tracker Upgrade: Teststand/DAQ
Teststand will be a central point of integration to investigate designs and execute production. A versatile and performant test system is essential.
SLAC has current pixel Turbo DAQ system running and helping on improving the LBNL strip stave teststand DAQ.
Investigating a teststand system with more on board processing power to speed up tests. Multi-channel readout for stave tests and cosmic telescope.
Thinking more generally to serve pixel and strip tests with the evolution to new Read Out Driver in mind.
Based on extensive DAQ design experience at SLAC.
July 7, 2008
SLAC Annual Program Review

10. Upgrade Tracker: Strip Stave Design
The development of the strip detector barrel stave is one of the most central tasks in tracker upgrade.
The Jun/08 stave review at CERN selected the stave concept pursued by Carl Haber et al at LBNL based on CDF runIIb upgrade with lower mass and more advanced electrical integration.
Dave Nelson from SLAC has been helping on teststand DAQ improvements and other electrical integration issues.
SLAC is interested in becoming a significant partner in the strip stave effort. Besides the electrical integration and testing, another possible area of contribution is mechanical design and testing in concert with the CO2 cooling development.
Based on SiD and past silicon experience and well located between LBNL and Santa Cruz.
July 7, 2008
SLAC Annual Program Review

11. Pixel B-Layer Replacement
Before superLHC, pixel b-layer is expected to reach its radiation dose limit by ~300fb-1, so that a replacement needs to be planned for 2012.
Can no long do simple b-layer replacement with <9 months shutdown. The b-layer task force reached recommendation for an insertion of new b-layer inside present detector on a smaller beam pipe.
Requires some of the new technology for sLHC upgrade to be ready in time for this to be viable.
SLAC may naturally become part of the project if seriously moving ahead.
July 7, 2008
SLAC Annual Program Review

12. Tracker Upgrade: Simulation and Layout
The tracker design layout is a central activity which critically relies on simulation. The local design choices also inevitably rely on simulation for selecting optimized choice.
The upgrade simulation has become a universal source of frustration due the inflexibility for introducing new geometry and heavy CPU demand.
The LCsim framework developed at SLAC for Linear Collider Detector designs, has very flexible and simple geometry input for producing fast design studies.
We are investigating a strategy to significantly improve the simulation utilities for ATLAS upgrade leveraging the strong simulation expertise at SLAC.
July 7, 2008
SLAC Annual Program Review

13. Trigger/DAQ: Current system
July 7, 2008
SLAC Annual Program Review

14. Trigger/DAQ Upgrade: Introduction
Trigger/DAQ upgrades/improvements are inevitable for ATLAS like every other experiment, but people are very busy with current system so far.
Known prospects at Phase 1 (by 2013)
some L1 improvements Calo, Muon, Central trigger
Level 1.5 Fast Track Trigger
Known prospects for Phase 2 (by 2017)
Rebuild of many frontend electronics to allow more L1 improvements with longer latency
ROD/ROL/ROB/ROS rebuild to improve bandwidth
L1 track trigger ?
Allow L1 rate to go >100KHz beyond the baseline ? Must decide soon or upgrade tracker design may prohibit this.
July 7, 2008
SLAC Annual Program Review

15. Trigger/DAQ Upgrade: New Readout System
Current Read Out Drivers (ROD) have 7 different flavors for different subsystems, which no one is proud of. They cannot last 10 years.
The Read Out Link (ROL) limits L1 rate to <100Khz.
Mike Huffer (SLAC) has a draft proposal to condense the entire ROD/ROL/ROB/ROS system into one layer of new ATCA (Advanced Telecommunications Computing Architecture) based readout system:
Reduces 932 RODs-> 234 ROMs
Can absorbe L2supervisor and ROIB as well
Improving bandwidth to L2/EF from 8GB/s -> nx45GB/s.
More intriguingly, the improved local density and high bandwidth of inter-module data availability is what one looks for in an ideal trigger system.
Based on extensive DAQ experience at SLAC and the Petacache project for fast random data access.
July 7, 2008
SLAC Annual Program Review

16. Trigger/DAQ Upgrade: New Readout Crate
July 7, 2008
SLAC Annual Program Review

17. Trigger/DAQ Upgrade: Petacache system
Prototype Petacache system
Rear Transition
Module
Reconfigurable Cluster Element (RCE) module
ATCA crate
Cluster Interconnect Board
July 7, 2008
SLAC Annual Program Review

18. Synergy between Projects
The choice of projects had the efficient use of lab
resource in mind to best utilize our expertise:
CO2 cooling, data transmission, teststand/DAQ are relevant for both strip and pixel detectors.
Teststand/DAQ, Gb/s transmission, Trigger/DAQ upgrade are based on the general Trigger/DAQ experience.
We strongly believe in the need to open up L1 bandwidth and working on the two key enabling aspects: tracker data transmission and DAQ upgrade.
July 7, 2008
SLAC Annual Program Review

19. SLAC Annual Program Review
Summary and Outlook
We have identified many interesting directions making significant contributions to the ATLAS upgrades and started some detailed R&D and design.
We believe these directions speak to the real needs to complement existing upgrade effort.
There are strong synergies among the investigated projects to maximize utilization of SLAC expertise.
We intend to keep the broad vision of the overall ATLAS upgrade needs and pay attention to system design issues. We believe SLAC can play a major role in the ATLAS upgrade.
July 7, 2008
SLAC Annual Program Review