Transcript R&D for Future Detectors

R&D for Future Detectors
Detector R&D continues on many fronts
Future Detectors will include:
 Neutrino detectors
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Hadron B Factory, Rare Kaon Decay, /Charm Detectors
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Massive, high efficiency
High bandwidth, high precision
Linear Collider Detectors
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Precision measurements
I will concentrate on the Linear Collider Detector R&D
J. Brau - ICHEP 2004 - R&D for Future Detectors
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Linear Collider Detector Requirements
Both Physics and Accelerator Constraints dictate the Detector
Requirements
Linear Collider creates new challenges and opportunities, different in
many respects from the challenges and opportunities of the LHC
detectors
Physics motivates
Triggerless event collection (software event selection)
Extremely precise vertexing
Synergistic design of detectors components:
vertex detector, tracker, calorimeters integrated for optimal jet reconstruction
New technologies based on recent detector inventions
Detector R&D of Next Few Years is Critical
J. Brau - ICHEP 2004 - R&D for Future Detectors
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Collider Constraints
Linear Collider Detector R&D has
had to consider two different sets
of collider constraints: X-Band
RF and Superconducting RF
designs
With the linear collider technology
selection, the detector efforts can
concentrate on one set of
parameters
The ILC creates requirements similar
to those of the TESLA design
J. Brau - ICHEP 2004 - R&D for Future Detectors
X-Band
GLC/NLC
SuperRF
TESLA
192
2820
#train/sec
150/120
5
bunch spacing
1.4 nsec
337 nsec
28800/23040
14100
length of train
269 nsec
950 msec
train spacing
6.6/8.3 msec
199 msec
crossing angle
7-20 mrad
0-20 mrad
#bunch/train
bunches/sec
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Linear Collider Events
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Simple events (relative to Hadron
collider) make particle level
reconstruction feasible
30% E
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Heavy boson mass resolution
requirement sets jet energy
resolution goal
ee  WW , ee  ZZ
t t event at 350 GeV
60% E
30% E
J. Brau - ICHEP 2004 - R&D for Future Detectors
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Calorimetry
Current paradigm: Particle/Energy
Flow (unproven)
 Jet resolution goal is 30%/E
 In jet measurements, use the
excellent resolution of tracker,
which measures bulk of the energy
in a jet
Neutral
Hadrons
EM
Charged
Hadrons
Headroom for confusion
Particles in Jet
Fraction of Visible
Energy
Detector
Resolution
Charged
~65%
Tracker
< 0.005% pT
negligible
Photons
~25%
ECAL
~ 15% / E
Neutral Hadrons
~10%
ECAL + HCAL ~ 60% / E
J. Brau - ICHEP 2004 - R&D for Future Detectors
~ 20% / E
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Energy/Particle Flow Calorimetry
Identify EM clusters not associated
with charged tracks (gammas)
Follow charged tracks into calorimeter
and associate hadronic showers
Remaining showers will be the neutral
hadrons
J. Brau - ICHEP 2004 - R&D for Future Detectors
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EM Calorimetry
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Physics with isolated electron and gamma
energy measurements require ~10-15% / E  1%
Particle/Energy Flow requires fine grained EM
calorimeter to separate neutral EM clusters
from charged tracks entering the calorimeter
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Small Moliere radius
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Iron
18.4 mm
Lead
16.5 mm
Tungsten
9.5 mm
Uranium
10.2 mm
Maximize BR2
Natural technology choice – Si/W calorimeters
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RM
Small sampling gaps – so not to spoil RM
Separation of charged tracks from jet core helps
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Tungsten
material
Good success using Si/W for Luminosity monitors at SLD, OPAL, ALEPH
Oregon/SLAC/BNL
CALICE
Alternatives –
Tile-Fiber (challenge to achieve required granularity)
Scintillator/Silicon Hybrid
Shaslik
Scintillator Strip
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Silicon/Tungsten EM Calorimeter
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J. Brau - ICHEP 2004 - R&D for Future Detectors
SLAC/Oregon/BNL
Conceptual design for a dense, fine
grained silicon tungsten calorimeter
well underway
First silicon detector prototypes are
in hand
Testing and electronics design well
underway
Test bump bonding electronics to
detectors by end of ’04
Test Beam in ’05
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Silicon/Tungsten EM Calorimeter (2)
 Pads
~5 mm to match Moliere radius
 Each six inch wafer read out by one chip
 < 1% crosstalk
 Electronics design
 Single MIP tagging (S/N ~ 7)
 Timing < 5 nsec/layer
 Dynamically switchable feedback capacitor
scheme (D. Freytag) achieves required
dynamic range: 0.1-2500 MIPs
 Passive cooling – conduction in W to edge
Angle subtended
by RM
GAP
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ECAL Prototype
9720 channels in prototype
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Preparations for DESY Beam Test
…DESY late 2004
Wafers:
Russia/MSU and
Prague/IOP
Tilt
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Y
X
ECAL
HCAL
PCB: LAL design,
production – Korea/KNU
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Other EM Calorimeters
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Tile-fiber
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Interesting readouts, such as SiPM
Option – shower max (scintillator strips or silicon pads)
Russia, ITEP
KEK, Kobe, Konan, Niigata, Shinshu, Tsukuba
Silicon Photomultiplier
Colorado
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Other EM Calorimeters (2)
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Silicon-scintillator Hybrid
Sc-W-Sc-W-Si-W-Sc-W-Sc-W
Como, ITE-Warsaw, LNF, Padova, Trieste
Kansas
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Scintillator strip
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Shashlik
J. Brau - ICHEP 2004 - R&D for Future Detectors
KEK, Kobe, Konan, Niigata, Shinshu, Tsukuba
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Hadron Calorimetry
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Role of Hadron Calorimetry in the Energy/Particle Flow
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Isolate and measure neutral hadrons
Approaches
Technology
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RPCs (Note promising work at IHEP-Beijing on oil-less resistive plate)
GEMs
Tile-fiber w/ APD SiPM HPD EBCCD
Scintillator strips
Readout
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Analog
Digital – high granularity
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MINICAL Prototype
Electron resolution in hadron calorimeter
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Studied different readout systems (PM, SiPM,
APD)
Established reliable calibration system,
checked long term stability, established
detailed MC simulation
• Developed stability monitoring system
J. Brau - ICHEP 2004 - R&D for Future Detectors
In 2005 move to hadron beam to fully test
HCAL performance
Hamburg, DESY, Dubna, MEPhI, Prague, LPI, ITEP
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Digital Hadron Calorimetry
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1 m3 prototype planned to test
concept
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Lateral readout segmentation: 1 cm2
Longitudinal readout segmentation: layer-bylayer
Gas Electron Multipliers (GEMs) and Resistive
Plate Chambers (RPCs) evaluated
Objectives
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Validate RPC approach (technique and physics)
Validate concept of the electronic readout
Measure hadronic showers with unprecedented
resolution
Validate MC simulation of hadronic showers
Compare with results from Analog HCAL
Argonne National Laboratory
Boston University
University of Chicago
Fermilab
University of Texas at Arlington
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Tracking
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Tracking for any modern experiment should be conceived as an
integrated system, combined optimization of:
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the inner tracking (vertex detection)
the central tracking
the forward tracking
the integration of the high granularity EM Calorimeter
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Pixelated vertex detectors are capable of track reconstruction on
their own, as was demonstrated by the 307 Mpixel CCD vertex
detector of SLD, and is being planned for the linear collider
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Track reconstruction in the vertex detector impacts the role of the
central and forward tracking system
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Inner Tracking/Vertex Detection
Detector Requirements
 Excellent spacepoint precision ( < 4 microns )
 Superb impact parameter resolution ( 5µm  10µm/(p sin3/2) )
 Transparency ( ~0.1% X0 per layer )
 Track reconstruction ( find tracks in VXD alone )
Concepts under Development for Linear Collider
 Charge-Coupled Devices (CCDs)
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demonstrated in large system at SLD
Monolithic Active Pixels – CMOS (MAPs)
DEpleted P-channel Field Effect Transistor (DEPFET)
Silicon on Insulator (SoI)
Image Sensor with In-Situ Storage (ISIS)
HAPS (Hybrid Pixel Sensors)
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Inner Tracking/Vertex Detection (CCDs)
Issues
 Readout speed and timing
 Material budget
 Power consumption
 Radiation hardness
R&D
 Column Parallel Readout
 ISIS
 Radiation Damage Studies
SLD VXD3
307 Mpixels
5 MHz  96 channels
0.4% X0 / layer
~15 watts @ 190 K
3.9 mm point res.
av. - 2 yrs and 307 Mpxl
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Column Parallel CCD
SLD Vertex Detector designed to read out
800 kpixels/channel at 10 MHz, operated at 5
MHz => readout time = 200 msec/ch
Linear Collider demands 250 nsec readout for
Superconducting RF time structure
Solution: Column Parallel Readout
LCFI (Bristol, Glasgow, Lancaster, Liverpool, Oxford, RAL)
(Whereas SLD used one
readout channel for each
400 columns)
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Column Parallel CCD (2)
Next Steps for LCFI R&D
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Bump bonded assemblies
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In-situ Storage Devices
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Resistant to RF interference
Radiation effects on fast CCDs
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Reduced clocking requirements
High frequency clocking
Detector scale CCDs w/ASIC & cluster finding
logic; design underway – production this year
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Image Sensor with In-situ Storage (ISIS)
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EMI is a concern (based on SLC experience) which motivates delayed
operation of detector for long bunch trains, and consideration of ISIS
Robust storage of charge in a buried channel during and just following
beam passage (required for long bunch trains)
Pioneered by W F Kosonocky et al IEEE SSCC 1996, Digest of Technical Papers, 182
T Goji Etoh et al, IEEE ED 50 (2003) 144; runs up to 1 Mfps.
• charge collection to photogate from 2030 mm silicon, as in a conventional CCD
• signal charge shifted into stor. register
every 50ms, providing required time slicing
• string of signal charges is stored during
bunch train in a buried channel, avoiding
charge-voltage conversion
• totally noise-free charge storage, ready
for readout in 200 ms of calm conditions
between trains for COLD LC design
• particles which hit the storage register
(~30% area) leave a small ‘direct’ signal
(~5% MIP) – negligible or easily corrected
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Radiation Effects in CCDs
Drift of charge over
long distance in CCD
makes detector very
susceptible to effects of
radiation:
• Transfer inefficiency
• Surface defects
N. Sinev et al.
Traps can be filled
• neutrons induce damage clusters
• low energy electrons create point
defects – but high energy electrons
create clusters – Y. Sugimoto et al.
• number of effective damage
clusters depends on occupation time
– some have very long trapping time
constants – modelled by K. Stefanov
J. Brau - ICHEP 2004 - R&D for Future Detectors
Hot pixels
• Expect ~1.5x1011/cm2/yr of ~20 MeV
electrons at layer-1
• Expect ~109/cm2/yr 1 MeV-equivalent dose
from extracted beamline
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Inner Tracking/Vertex Detection (MAPs)
Concept
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Standard VLSI chip, with thin, un-doped
silicon sensitive layer, operated undepleted
R&D
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Advantages
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decoupled charge sensing and signal
transfer (improved radiation tolerance,
random access, etc.)
small pitch (high tracking precision)
Thin, fast readout, moderate price, SoC
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Strasbourg IReS has been working on
development of monolithic active
pixels since 1989; RAL also now.
First IReS prototype arrays of a few
thousands of pixels demonstrated the
viability of technology and its high
tracking performances.
First large prototypes now fabricated
and being tested.
Current attention focussed on readout
strategies adapted to specific
experimental conditions.
Technology will be used at STAR
Parallel R&D: FAPS (RAL)
 10-20 storage capacitors/pixel
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Inner Tracking/Vertex Detection (DEPFET)
Concept
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Properties
Field effect transistor on top of fully
depleted bulk
All charge generated in fully depleted
bulk; assembles underneath the
transistor channel; steers the
transistor current
Clearing by positive pulse on clear
electrode
Combined function of sensor and
amplifier
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16x128 DEPFET-Matrix
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low capacitance ► low noise
Signal charge remains undisturbed by
readout ► repeated readout
Complete clearing of signal charge ► no
reset noise
Full sensitivity over whole bulk ► large
signal for m.i.p.; X-ray sens.
Thin radiation entrance window on
backside ► X-ray sensitivity
Charge collection also in turned off
mode ► low power consumption
Measurement at place of generation ►
no charge transfer (loss)
Operation over very large temperature
range ► no cooling needed
MPI Munich, MPI Halle, U. Bonn, U. Mannheim
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Central Tracking
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Two general approaches being developed for the Linear Collider
TPC (or Jet Chamber)
• Builds on successful experience of PEP-4, ALEPH, ALICE, DELPHI,
STAR, …..
• Large number of space points, making reconstruction straight-forward
• dE/dx  particle ID, bonus
• Minimal material, valuable for calorimetry
• Tracking up to large radii
Silicon
• Superb spacepoint precision allows tracking measurement goals to be
achieved in a compact tracking volume
• Robust to spurious, intermittent backgrounds
• linear collider is not storage ring
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Central Tracking (TPC)
Issues for LC TPC
 Optimize novel gas amplification systems
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Conventional TPC readout based on MWPC and pads
 limited by positive ion feedback and MWPC response
Improvement by replacing MWPC readout with micropattern gas
chambers (eg. GEMs, Micromegas)
 Small structures (no EB effects)
 2-D structures
 Only fast electron signal
 Intrinsic ion feedback suppression
Neutron backgrounds
Optimize single point and double track resolution
Performance in high magnetic fields
Demonstrate large system performance with control of systematics
J. Brau - ICHEP 2004 - R&D for Future Detectors
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TPC Gas Amplification System
New concept for gas amplification at the end flanges:
Replace proportional wires with Micro Pattern Gas Detectors
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Gas Electron Multiplier (GEM) - F. Sauli, 1997
or Micromegas - Y. Giomataris et al., 1996
GEM
Conventional
TPC: Wires
Also being investigated: Medipix2, CMOS pixel sensor w/GEM
(NIKHEF, Saclay, Twente/Mesa, CERN)
J. Brau - ICHEP 2004 - R&D for Future Detectors
Small structures (no EB effects)
2-D structures
Only fast electron signal
Intrinsic ion feedback suppression
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Gas Electron Multiplier (GEM) for TPC Readout
140 mm
•50 µm kapton foil,
double sided copper coated
•75 µm holes, 140 µm pitch
75 mm
•GEM voltages up to 500 V
yield 104 gas amplification
Use GEM towers
for safe operation
(COMPASS)
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Micromegas for TPC Readout
50 mm pitch
•asymmetric parallel plate chamber
with micromesh
•saturation of Townsend coefficient
mild dependence of amplification
on gap variations
•ion feedback suppression
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TPC Resolution Studies with Magnetic Field
and 1 T at Triumf
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TPC Resolution and Ion Feedback
Ion feedback improves with
(GEM) or is independent of
(Micromegas) magnetic field
GEM
transverse resolution (mm)
Magnetic field improves
resolution
B=0
P5 gas
Double-GEM
B = 0.9 T
B = 1.5 T
100 micron
30 mm
drift time (50 ns bins)
J. Brau - ICHEP 2004 - R&D for Future Detectors
300 mm
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Central Tracking (Silicon)
With superb position resolution, compact tracker is possible which
achieves the linear collider tracking resolution goals
Compact tracker makes the calorimeter smaller and therefore cheaper,
permitting more aggressive technical choices (assuming cost constraint)
Linear Collider backgrounds (esp. beam loss) extrapolated from SLC
experience also motivate the study of silicon tracking detector, SiD
Silicon tracking layer thickness
determines low momentum
performance
3rd dimension may be achieved
(1.5% / layer)
with segmented silicon strips,
or silicon drift detectors
(TPC)
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Central Tracking (Silicon)
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Optimizing the
Configuration
support
Cooper, Demarteau, Hrycyk
R. Partridge
H. Park
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Central Tracking (Silicon)
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Strip length:
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Short strips segments (10 cm slices) are interesting for less noise,
shorter shaping time, better time stamping.
Longer strips, long shaping time designs are also under development,
motivated by minimized material in tracking volume.
Two ASICs for long shaping will soon go to fab.
Santa Cruz ASIC power cycle
LPNHE Preamp
Power
Off
Response
to ¼, 1
and 4 mip
signals
Power On
8 msec power-off
period (not to scale)
60
msec
power
restorat
ion
Note, silicon detector R&D also supports TPC detector where intermediate and forward tracking are needed
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Silicon Tracking w/ Calorimeter Assist
Primary tracks started
with VXD reconstr.
V0 tracks reconstructed from ECAL stubs
E. von Toerne
J. Brau - ICHEP 2004 - R&D for Future Detectors
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Very Forward Instrumentation
• Hermiticity depends on excellent coverage in the forward region,
and forward system plays several roles
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maximum hermiticity
precision luminosity
shield tracking volume
monitor beamstrahlung
• High radiation levels must be handled
• 10 MGy/year in very forward detectors
TESLA Goal: ΔL/L: 10-4 (exp.)
ΔL/L: 10-4 (theo.)
Ref: OPAL (LEP)
ΔL/L: 3.4 x 10-4 (exp.)
ΔL/L: 5.4 x 10-4 (theo.)
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Machine Detector Interface
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A critical area of detector R&D which must be optimized is where
the detector meets the collider
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Preserve optimal hermiticity
Preserve good measurements
Control backgrounds
Quad stabilization
20 mr crossing angle, silicon detector
J. Brau - ICHEP 2004 - R&D for Future Detectors
Zero crossing angle, TPC detector
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Detector Beamline Instrumentation
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Polarized electrons (and perhaps positrons)
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Polarimeter
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Electron energy
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Energy spectrometer
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0.2% goal
200 ppm required
Beam energy profile
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Differential luminosity measurement
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knowledge of beamstrahlung effects required
S. Boogert
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Other Detector R&D Efforts
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Muon Detectors
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Detector Solenoid
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RPCs
Scintillator strips w/ MAPMTs
All detector concepts under study assume a strong magnetic field of
strength greater than 3T with a coil of large diameter.
The large volume required for this high-field magnet is a challenge, but
experience with the 4T solenoid for CMS will be very helpful.
This experience has been utilized in detector designs, but requires additional
understanding.
Need to study compensation issues if machine has a crossing angle.
Quad stabilization
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Machine-detector-interface issue crucial for the detector.
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Summary
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Linear Collider Experimental Program needs advances in detector
technology specific to the challenges of the LC:
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High granularity, high precision, triggerless operation
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A coordinated, R&D effort is underway world-wide to develop the
advanced detectors needed to capitalize on the special discovery
opportunities which will be created by the construction of the linear
collider.
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The Detector community has been preparing, but eagerly awaiting
the technology choice to make the focused R&D program.
With the technology decision, it is now time for a significant
ramping up of this effort.
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