1. The Other Detectors and Associated R&D
Jim Brau
April 4, 2003
In addition to the TESLA detector, some other detector configurations have been under study:
JLC Detector
North American SD
North American L (similar to TESLA/JLC)
Different choices have been made, aimed at the same physics
Thanks to Y. Fujii, and
my NAmer colleagues,
for help in preparing
this talk
Jim Brau, Amsterdam, April 4, 2003

2. Comparison of Detector Configurations2
144
(Ray Frey) 3 6o 6o
Jim Brau, Amsterdam, April 4, 2003

3. LC Detector Requirements
Any design must be guided by these goals:
a) Two-jet mass resolution comparable to the natural widths of W and Z for an unambiguous identification of the final states.
b) Excellent flavor-tagging efficiency and purity (for both b- and c-quarks, and hopefully also for s-quarks).
c) Momentum resolution capable of reconstructing the recoil- mass to di-muons in Higgs-strahlung with resolution better than beam-energy spread .
d) Hermeticity (both crack-less and coverage to very forward angles) to precisely determine the missing momentum.
e) Timing resolution capable of separating bunch-crossings to suppress overlapping of events .
Jim Brau, Amsterdam, April 4, 2003

4. SD (Silicon Detector) Conceived as a high performance detector for NLC
Reasonably uncompromised performance
But
Constrained & Rational cost
parametric cost analysis
Accept the notion that excellent energy flow calorimetry is required, and explore optimization of a Tungsten-Silicon EMCal and the implications for the detector architecture…
Recently this configuration
has been getting serious
attention, as a result of studies
being organized by M. Breidenbach
Jim Brau, Amsterdam, April 4, 2003

5. Architecture arguments
Silicon is expensive, so limit area by limiting radius
Get back BR2 by pushing B (~5T)
This argument may be weak, considering quantitative cost trade-offs. (see plots)
Maintain tracking resolution by using silicon strips
Buy safety margin for VXD with the 5T B-field.
Keep (?) track finding by using 5 VXD space points to determine track
tracker measures sagitta.
Jim Brau, Amsterdam, April 4, 2003

6. Scale of EMCal & Vertex Detector
SD Configuration
Coil
Scale of EMCal & Vertex Detector
Jim Brau, Amsterdam, April 4, 2003

7. Silicon Tungsten EMCal
Figure of merit something like BR2/s,
where s = rpixel  rMoliere
Maintain the great Moliere radius of tungsten (9 mm) by minimizing the gaps between ~2.5 mm tungsten plates. Dilution is (1+Rgap/Rw)
Could a layer of silicon/support/readout etc. fit in a 2.5 mm gap? (Very Likely)
Even less?? 1.5 mm goal?? (Dubious)
Requires aggressive electronic-mechanical integration!
Jim Brau, Amsterdam, April 4, 2003

8. Silicon Tungsten EMCal (cont.)
Diode pixels ~ 5 mm square on largest hexagon fitting in largest available wafer.
6” available now – 300 mm when??
Consider m tracking as well as E flow in picking pixel dimension.
Develop readout electronics of preamplification through digitization, IO on bump bonded chip.
Upgrade would be full integration of readout on detector wafer.
Optimize shaping time for small diode capacitance.
Probably can do significant bunch localization within train.!!!
Jim Brau, Amsterdam, April 4, 2003

9. Structure
Pixels on 6” Wafer
Jim Brau, Amsterdam, April 4, 2003

10. Thermal Management
Cooling is a fundamental problem: GLAST system is ~2 mW/channel. Assume 1000 pixels/wafer and power pulsing duty factor for NLC of 10-3 (10 Hz), for 2 mW average power.
Preliminary engineering indicates goal of under 100 mW ok.
Assume fixed temperature heat sink (water cooling) at outer edge of an octant, and conduction through a ~1 mm thick Cu plane sandwiched with the W and G10: ΔT~140C.
OK, but need power pulsing!!! ..and maintaining the noise/resolution is a serious engineering challenge.
Find thermal FEA plot!
Jim Brau, Amsterdam, April 4, 2003

11. Vertex Detectors Design CCD’s for Optimal shape ~2 x 12 cm
Multiple (~20) ReadOut nodes for fast readout
Thin -≤ 100 µ
Improved radiation hardness
Low power
Readout ASIC
No connectors, cables, output to F.O.
High reliability
Increased RO speed from SLD VXD3
Lower power than SLD VXD3
Jim Brau, Amsterdam, April 4, 2003

12. Vertex Detectors, continued
Mechanical
Eliminate CCD supports, “stretch” Si.
Very thin beampipes??
Cooling
Simulation
Quantify/justify needs
SLD VXD3 has been removed from SLD for damage analysis of CCD’s.
Jim Brau, Amsterdam, April 4, 2003

13. Silicon Tracker
SLC/SLD Prejudice: Silicon is robust against machine mishaps; wires & gas are not.
Mechanical:
Low mass C-Fiber support structure
Chirped Interferometry Geodesy (Oxford System) Atlas has developed a beautiful chirped interferometric alignment system – a full geodetic grid tieing together the elements of their tracker. Can such a system reduce requirements on the space frame precision and stability – reducing its mass and cost?
Silicon Development
Build on GLAST development,
Add double ended bond pads, and
Develop special ladder end detector w/ bump bond array
Reduce mass, complexity at ends
Employ track finding in 5-layer CCD vertex detector
Jim Brau, Amsterdam, April 4, 2003

14. Tracker Electronics
Plan is to string 10 cm square detectors to barrel half lengths and readout from ends.
Design “end” detectors to route strips to rectangular grid for bump bonding to read out chip (ROC).
ROC is ASIC with all preamplification, shaping, discrimination, compression, and transmission functionality. Includes power pulsing.
Hasn’t been done!
Electronics:
Develop RO for half ladder (~1.5 m)
Jim Brau, Amsterdam, April 4, 2003

15. HCal
Hcal assumed to be 4 l thick, with 46 layers 5 cm thick alternating with 1.5 cm gaps.
Could use “digital” detectors, eg high reliability RPC’s (Have they been invented yet???)
Hcal radiator non-magnetic metal – probably copper or stainless
Tungsten much too expensive
Lead possible, but mechanically more painful.
Hcal thickness important cost driver, even though Hcal cost small.
And where is it relative to coil?
Jim Brau, Amsterdam, April 4, 2003

16. HCal Location Comparison
2l l l
80 M$
60 M$
40 M$
20 M$
0 M$
0 M$
-10 M$
-20 M$
-30 M$
Scale – Relative to 4 l Inside!!
2l l 6l
Coil
Coil
Hcal inside coil
HCAL outside coil
Jim Brau, Amsterdam, April 4, 2003

17. Coil and Iron
Solenoid field is 5T – 3 times the field from detector coils that have been used in the detectors. - CMS will be 4T.
Coil concept based on CMS 4T design. 4 layers of superconductor about 72 x 22 mm, with pure aluminum stabilizer and aluminum alloy structure.
Coil Dr about 85 cm
Stored energy about 1.5 GJ (for Tracker Cone design, R_Trkr=1.25m, cosqbarrel=0.8). (TESLA is about 2.4 GJ) [Aleph is largest existing coil at 130 MJ] Br Bz
Jim Brau, Amsterdam, April 4, 2003

18. Flux Return/Muon Tracker
Flux return designed to return the flux! Saturation field assumed to be 1.8 T, perhaps optimistic.
Iron made of 5 cm slabs with 1.5 cm gaps for detectors, again “reliable” RPC’s.
Jim Brau, Amsterdam, April 4, 2003

19. More Cost trade-offs D $ vs R_Trkr ~1.7M$/cm
Delta $, Fixed BR2=5x1.252
Jim Brau, Amsterdam, April 4, 2003

20. Cost Control Good sense requires cost control:
Detectors will get about 10% of the LC budget: 2 detectors, so $350 M each
We will want the most physics capability we can imagine: Great
Vertexing- Stretched CCD’s
Tracking –Silicon Strips
B – 5T
EMCal – Silicon-tungsten
Hcal – Cu(??) – R2PC
Muon Tracking – Fe- R2PC
Is this a sensible approach?
Jim Brau, Amsterdam, April 4, 2003

21. Detector R&D in North America
Diversity of R&D projects
Not necessarily aimed at specific detector configurations
Several years of support for simulation is now in transition into invigorated hardware effort
funding for this new era is nearly (but not quite) established
Jim Brau, Amsterdam, April 4, 2003

22. In addition focussed R&D effort continues in Canada
A University Program of Accelerator and Detector Research for the Linear Collider
In addition focussed R&D effort continues in Canada
Jim Brau, Amsterdam, April 4, 2003

23. North American Tracking
ALCPG Tracking Working Group:
B. Schumm/D. Karlen/K. Riles
Jim Brau, Amsterdam, April 4, 2003

24. Jim Brau, Amsterdam, April 4, 2003
Gaseous Tracking
Jim Brau, Amsterdam, April 4, 2003

25. North American Vertex Detector R&D
Oregon/Yale/SLAC
Radiation hardness studies
removed SLD VXD3 for analysis
spare ladder studies
Developing new CCD detector prototype
Studying mechanical issues
Design readout for X-Band operation
Oklahoma/Boston/Fermilab
Development and design of an LC ASIC for CCD readout and data
Purdue
Study of the Mechanical Behavior of Thin silicon and the
Development of hybrid silicon pixels for the LC
Vertex Detector
ALCPG Vertex Detector Working Group:
J. Brau, N. Roe
Jim Brau, Amsterdam, April 4, 2003

26. Calorimeter Detector R&D in N. America
ALCPG Calorimeter Working Group:
R. Frey/A. Turcot/D. Chakraborty
Calorimeter Detector R&D in N. America
Jim Brau, Amsterdam, April 4, 2003

27. Jim Brau, Amsterdam, April 4, 2003

28. Jim Brau, Amsterdam, April 4, 2003

29. Scintillator Based Muon System R&D
ALCPG Muon Working Group:
G. Fisk
Scintillator Based Muon System R&D
Jim Brau, Amsterdam, April 4, 2003

30. Muon System R&D Summary
Hardware Progress:
- First look at multi-anode PMT.
- Scint. Extrusion Machine delivered & being installed.
- Expect first samples ~ June.
- Measurements of existing
scintillator using visible light photon counters (VLPCs).
Simulation Studies:
- Single m & p tracking and ID.
- Improved eff at low p with dE/dx corrections for track matching.
- Pion punch-through ~1.4% at
50 GeV with (q, j) track matching.
To Do:
- m’s in Jets; muon syst calorimetry.
Punch-through Prob. vs. pp 1% pp 50
Jim Brau, Amsterdam, April 4, 2003

31. Beamline Instrumentation
High Priority Items:
dL/dE analysis
complete analysis to extract both tail and core
understand external inputs (asymmetries, offsets)
possible to extract correlations (energy, polarization)?
Extraction line studies
expected distributions with disrupted beam
expected backgrounds at detectors
Forward Tracking/Calorimetry
Realistic conceptual design for NLC detector
Expected systematics eg: alignment
Beam Energy Width
Understand precision of beam-based techniques
Possible with x-line WISRD?
ALCPG Beamline Instrumentation Working Group:
M. Woods /E. Torrence/D. Cinabro
Jim Brau, Amsterdam, April 4, 2003

32. Beamline Instrumentation
Ongoing R&D Work:
Luminosity
dL/dE analysis (SLAC, Wayne St.)
Beamstrahlung Monitor (Wayne St.)
Pair monitor (Hawaii, in collab. with Tohoku)
Forward calorimeter (Iowa St.)
Energy
WISRD spectrometer (UMass, Oregon)
BPM spectrometer (Notre Dame)
Polarization
x-line simulations (SLAC, Tufts)
Quartz fiber calorimter (Iowa, Tennessee)
Many important topics uncovered...
Jim Brau, Amsterdam, April 4, 2003

33. NLC Forward Masking, Calorimetry & Tracking 2003-04-01
-0.5
-0.4
-0.3
-0.2
-0.1
0.1
0.2
0.3
0.4
0.5 1
1.5 2
2.5 3
3.5 4
ECAL
HCAL
117mrad
36mrad
QD0
Pair-LuMon
LowZ Mask
Exit 3.5m
Inst. Mask W
Support Tube
BeamPipe
NLC Forward Masking, Calorimetry & Tracking
Forward Detector
ALCPG IR/Backgrounds Working Group:
T. Markiewicz, S. Hertzbach
Jim Brau, Amsterdam, April 4, 2003

34. Forward Detector Lum-PairMon @ z=3.5m 1cm radius 2cm radius
Jim Brau, Amsterdam, April 4, 2003

35. Testbeams World-wide R&D web page on testbeams:
Assessment underway on testbeam needs and resources
Recent study:
Linear Collider Calorimeter Testbeam Study Group Report
S. Magill, J. Repond, A. S. Turcot, J. Yu
This report should be broadened to include other subsystems
Jim Brau, Amsterdam, April 4, 2003

36. Test Beam Needs (collected by Gene Fisk to date)
Jim Brau, Amsterdam, April 4, 2003

37. JLC Design The JLC strategy for choice of technologies in baseline R&D
1) No Proof-of-Principle R&D.
2) Constructible within affordable cost.
JLC official view, as stated in the 'Roadmap Report' ( )
"Extensive R&D studies have been carried out in Asia, Europe, and North America toward the same goal, but with slightly different technology choices in some sub-detectors. International cooperation in common technologies and in cross- examination on different approaches is maintained. Design of the total detector system will be done within a few years by integrating the best technologies achieved."
Jim Brau, Amsterdam, April 4, 2003

38. JLC Detector Muon Chamber Calorimeter Central Drift Chamber
Superconducting
Magnetic Coil (2 T)
Jim Brau, Amsterdam, April 4, 2003

39. JLC Detector R&D 3.1) Vertex Detector a) done or finishing soon
excellent spatial resolution (plot)
room-temperature operation (good S/N by Multi-Pinned Phase operation)
radiation hardness measurement : 90Sr, 252Cf, electron-beam irradiation=in analysis
b) in progress or to do
CTI improvement : two-phase clocking, thermal charge injection, notch structure (plot)
fast readout : test-board fabrication in progress
thinned CCD (20micrometer) : flatness, stability, reproducibility
precise estimation of background by a full simulation with detailed beamline components
Jim Brau, Amsterdam, April 4, 2003

40. JLC Detector R&D 3.2) Intermediate Tracker 3.3) Central Tracker
in progress or to do
Si-sensor fabrication and test-module construction
Simulation study of VTX-IT-CT combined tracking (plot)
3.3) Central Tracker
a) done or finishing soon
spatial resolution
effect of gas contamination
Lorentz angle measurement
dE/dx measurement
positive-ion space-charge effect (plot)
b) in progress or to do
Two-track separation performance with a test chamber using parallel laser beam (plot)
Z-measurement with charge-division
Creeping of aluminum wire
Full-simulation study on Pt resolution, bunch-tagging capability, and physics sensitivity
Jim Brau, Amsterdam, April 4, 2003

41. JLC Detector R&D 3.4) Calorimeter 3.5) Muon System
a) done or finishing soon
hardware compensation, energy response linearity, energy resolution (stochastic term) (plot)
machine-ability of tiny tiles, assemble-ability
performance of WLS-readout SHmax
b) in progress or to do
granularity optimization with a full simulation
photon yield and non-uniformity improvement for RectTile EMcal
performance study of strip-array EMcal : beamtest, simulation, ghost-rejection (plot)
direct-APD-readout SHmax
photon detectors (multi-channel HPD/HAPD, EBCCD etc.)
3.5) Muon System
no effort
Jim Brau, Amsterdam, April 4, 2003

42. JLC Detector R&D 3.1) Vertex Detector
excellent spatial resolution
CTI improvement : two-phase clocking, thermal charge injection, notch structure
Jim Brau, Amsterdam, April 4, 2003

43. JLC Detector R&D 3.2) Intermediate Tracker
Simulation study of VTX-IT-CT combined tracking
Jim Brau, Amsterdam, April 4, 2003

44. JLC Detector R&D 3.3) Central Tracker
positive-ion space-charge effect
Two-track separation performance with a test chamber using parallel laser beam
Jim Brau, Amsterdam, April 4, 2003

45. JLC Detector R&D 3.4) Calorimeter
hardware compensation, energy response linearity, energy resolution (stochastic term)
performance study of strip-array EMcal : beamtest, simulation, ghost-rejection
Jim Brau, Amsterdam, April 4, 2003

46. Conclusion There is much to learn from the differing choices
of independent groups in the world that are developing full LC detector concepts and studying their advantages and disadvantages.
We much do an honest comparison and assessment leading to improved detectors that we will eventually build and use for the LC physics program.
Jim Brau, Amsterdam, April 4, 2003

47. Extras
Jim Brau, Amsterdam, April 4, 2003

48. EMCal Readout Board ~1m Silicon Diode Array Readout Chip
Network Interconnect
~1m
Jim Brau, Amsterdam, April 4, 2003

49. Luminosity, Energy, Polarization
Beam Energy
DEbeam ~ 200 ppm from TeV
Upstream BPM + Downstream WISRD Spect.
mmg in forward detector (~200 mRad)
Polarization
DP/P ~ 0.25% (Pe- only) DP/P ~ 0.10% (Pe+ also)
Downstream Compton polarimeter
t-channel WW scattering
Absolute Luminosity
DL/L ~ 0.2% (adequate, not perfect)
Forward calorimeter around mRad
Luminosity Spectrum
Core width to ~ 0.1%, tail level to 1%
e+e- acolinearity (necessary but not sufficient!)
Strategy document
just completed
Jim Brau, Amsterdam, April 4, 2003

50. Luminosity Spectrum Acolinearity problems
Energy, dL/dE both correlated with position along bunch.
Measures boost, not s’
Energy imbalance, width imbalance must be input
Independent real-time width measurements?
200 uRad kicks from disruption alone (larger than target accuraccy)
Many other offsets/degrees of freedom which must be input.
Putting together complete analysis including
‘realistic’ mis-aligned machine decks from TRC report
Jim Brau, Amsterdam, April 4, 2003