Transcript SLUO July172009.seiden

Introduction to U.S. ATLAS
Upgrade R&D.
July 17, 2009
A. Seiden
SLUO LHC Workshop
July 17, 2009
Upgrade Plan
ATLAS has had an upgrade program spearheading R&D toward higher
luminosity operation for the past few years. This has evolved into a
two stage upgrade plan. In Phase 1 the LHC would upgrade the
machine to operate at a luminosity of about 3x1034. Accompanying
this are detector upgrades:
1) An additional pixel layer at very small radius to ensure good tracking
performance for a number of years at 3x1034 luminosity (called IBL).
2) Completion of forward muon coverage that had initially been staged.
3) Trigger/DAQ improvements for the higher luminosity.
The completion schedule for these upgrades is around 2014. The start
date for U.S. participation in construction might be 2011, but this is
dependent on various agreements with the government agencies. The
furthest along in the process of defining a design from among the three
projects above is the IBL where there has just been a kick-off meeting
at CERN on July 8. A TDR for this element is scheduled for completion
around 9 months from now.
SLUO LHC Workshop
July 17, 2009
ATLAS Process for R&D Projects
The upgrade program is managed
jointly through a special steering group
and by the ATLAS project office.
Official R&D projects are vetted by the
steering group and approved by overall
ATLAS.
The upgrade program has
funded the development of a new chip
and several detector concepts needed
for realizing the IBL.
SLUO LHC Workshop
July 17, 2009
Phase 2 Upgrade
A more ambitious program, but with unclear timetable (until LHC runs and can establish a reliable
luminosity plan) is the development of a detector that
can run at even higher luminosity, the goal being
1035. This is called the Phase 2 upgrade of ATLAS.
During this stage the tracker would be replaced by an
all silicon tracker, with the present design goal being
to do tracking in an environment of 400 collisions per
50 nsec. beam crossing. Note that the present
tracker has a limited lifetime (of about 3 to 4 years at
3x1034) so even very extended running at the Phase 1
luminosity will require a new tracker. Example of a
Phase 2 tracker concept on the next slide.
SLUO LHC Workshop
July 17, 2009
New Inner Detector: 4 Pixel, 3 Short
Strip, 2 Long Strip Layers
Units are cm.
Provides layout for simulation studies, including occupancies
expected in the detectors. Provides basis for costing. Now
working on optimizing the design, including engineering
details, but still based on same number of layers.
SLUO LHC Workshop
July 17, 2009
Manpower Issues
The new inner detector has a very large
increase in channel count, area, and required
radiation hardness as compared to the
present ATLAS silicon tracker, which has 3
pixel layers and four double sided strip
layers. Construction will require a significant
increase in the number of groups
participating as compared to the original
detector. A number of additional groups are
in fact engaged: BNL, SLAC, Yale, Penn,
Stony Brook, NYU, Washington, etc.
SLUO LHC Workshop
July 17, 2009
Items to Develop (R&D Program)
 Two types of pixel detectors:
3-D detector for innermost layers (alternative diamond detector).
n-on-p detector for outer pixel layers (alternative is n-on-n detector).
 n-on-p short and long-strip detectors for the strip layers.
 New front-end chips for these as well as associated controller and data
collection chips. A major goal is to reduce power in the front-ends.
 New optical readout components (exploring several options for
VCSELs and PIN diodes).
 New powering schemes (to power many modules per input power cable)
to minimize mass in the detector and maintain safety for the chips.
 New mechanical scheme for holding individual sensors to reduce mass
and complexity.
 New cooling system to improve on present detector (a possible choice is
CO2 ).
 New off-detector system to collect data.
 Also looking at the possibility of a first level tracking trigger.
SLUO LHC Workshop
July 17, 2009
Other Elements that Have to be Upgraded
Depending on the eventual Phase 2 plan other detector
elements may require upgrading. Most likely as those most
forward since they receive the largest dose. These are the:
Forward calorimeter, liquid argon electronics (calorimeter itself
should work fine), and forward muon systems.
Additonal systems of concern are the tile calorimeter
electronics and possibly muon electronics. The trigger for
isolated muons also needs to somehow be improved due to rate
limitations.
Increases in luminosity also require further improvements in the
Trigger/DAQ system.
However all estimates of lifetime have large uncertainties till we
take data and establish rates. Also need physics feedback to
see if it is crucial to emphasize any specific detection
capabilities. To date we have assumed that upgrades will
maintain the overall ATLAS capabilities.
SLUO LHC Workshop
July 17, 2009
On to Specific Contributions
The subsequent talks will give you a
feeling for the specifics of some of the
projects underway for the Upgrade
program! These are projects in which
the local SLUO affiliated groups have
played an important role.
SLUO LHC Workshop
July 17, 2009