1. Pixel Upgrade Status & Plans
CMS Engineering
&
Integration Meeting
CERN, 2. March 2011
R. Horisberger, PSI

2. Present Pixel Detector with 3 hit coverage works very well !
Measured resolution
srf = 13mm
sz = 25mm
Pixel Thresholds
mean = 2450 e
3 barrel layers & 2 F/B disks
easy & quick removal / installation in shut down
designed for luminosity < 1x1034 cm-2 sec-1
design fluence < 0.6x1015n/cm2 (tolerate more) 1

3. Proposed Pixel Upgrade
BPIX 3 Layer  4 Layers
FPIX 2x2 Disk  3x2 Disk
Increase number pixel tracking points 3  4
CO2 cooling based Ultra Light Mechanics
Shift material budget out of tracking h–region
Significant X/X0 reduction
Minimize 1 Layer radius
reduced impact dxy & dz error
ROC modifications for operation up to L ~ 2x1034
Use same cabling  DC/DC converters for power
 320MHz digital readout on fibres
 pixel tracking & vertexing significant improved and robustified 2

4. Shift material budget out of tracking region
Current BPIX Services
Upgraded BPIX Services
h<2.2 : weight = 16.9 Kg (3 layer)
h<2.2 : weight = 6.5 Kg (4 layer)
shift out
Current 3 layer
Upgraded 4 layer
Current 2 disk
Upgraded 3 layer
Radiation length
h ~1.5 : g-conversion for H gg from 22% to 11% for new 4 Layer Pixel System 3

5. BPIX / FPIX Envelope Definition & Insertion into CMS
Barrel Supply Tube
Insertion of new system verified
CF hinge
All identical disks using all identical Vanes and one geometry 2x8 modules.
CO2 cooling loops
stainless steel pipes
wall thickness = 100m
diameter =1.8mm 4

6. BPIX Upgrade Mechanics
 1216 modules  81M pixel
(1.6 x present BPIX)
(present)
baseline
Full module type only
Layer 1: R 39mm; 16 faces
Layer 2: R 68mm; 28 faces
Layer 3: R 109mm; 44 faces
Layer 4: R 160mm; 64 faces
Clearance to beam pipe 4mm
current
22.5mm
24.7mm
upgrade
< 29.5mm >
If beam pipe r < 22.5 mm  1st Layer: 12 faces <R>=29.5mm 5

7. Ultra Light Mechanics BPIX Prototype
Layer 1
100 bar pressure tested
Tubes, 50m wall thickness
Weight Layer1 42g + 7g CO2  30% of old first layer X/X0
Present Pixel Barrel
z-impact param. res. [mm]
azimutal angle F
Low mass CO2 cooling pipes
 less multiple scattering in
impact parameter resolution 6

8. FPIX Mechanics & Prototype
inner & outer ring for easier replacement
6 disk of 112 sensors each  672 modules
one module size with 2x8 ROC / module
 10’752 ROC’s ~ 44M pixel (2.5 x old FPIX)
CO2 cooling
loops 7

9. Impact Parameter of old / new Pixel System
Barrel Region
Forward Region
0<h<1.0
transverse IP
current
transverse IP
upgraded
Barrel Region
Forward Region
0<h<1.0
0.6
current
longitudinal IP
~0.75
longitudinal IP
upgraded
IP estimate for
12 face 1st Layer
Beam pipe r<23mm : 16 faces to 12 faces  reduce MS term by ~0.75  total 0.75x0.6 = 0.45 ! 8

10. Upgrade of Pixel Readout Chain
12 time
stamps
32 data buffers
1176mm
300mm
PSI46 ROC
Present ROC for 1st Layer:
Luminosity bx-spacing Data Loss
1x1034cm-2s nsec %
50nsec %
2x1034cm-2s nsec %
50nsec ~50%
50nsec operation of LHC was not planned in original ROC architecture in 1998.
m-twisted CCA pair (Copper-Cladded Aluminum)
Data losses removed by ROC changes:
1) increase depth of Status
- data buffer 32  done
- timestamps 12  done
2) add readout buffer done
3) 160Mbit/sec serial binary data out now
4) deal with PKAM events  DAQ resync
Talk about front end chip design – for upgraded system
1m long low mass link at 320MHz , chips done !
3.125 ns
40mV 9

11. Current / Upgraded Pixel Track Seeding at 2x1034cm-2s-1
Reduced data loss and quadruplet seeding improves efficiency and reduces fake rate ! 10

12. b-tagging of Current / Upgraded Pixel System
ttbar 80<pt<120 GeV Combined Seondary Vertex Tagger
~5x fake rate
reduction
+25% efficiency
gain
Lumiosity =
Current
detector
Upgraded
Efficient b-jet tagging crucial to many physics analysis
e.g. 4-b-jet channel  fake rate reduction by factor ~600 or ~2.4 x signal gain 11

13. Pixel Upgrade Schedule13

14. New LHC Schedule drives Pixel Schedule
2011
2012
2013
2014
2015
2016
2017
2018
LHC machine
7 TeV TS
7 TeV
shut down LS1
14 TeV TS
14 TeV TS
14 TeV TS
14 TeV
LS2
CMS open
( )
( )
( )
present beampipe
new beampipe (45mm)
Pixel (rep/ mod/ test/ inst)
new pixel instal. test
PP1 preparation
Pixel PixTIF
CO2 plant (pre) install.
( )
CO2 – pixel load tests
Pixel (instal./comm./oper)
The new LHC schedule after Chamonix 2011 constraints our possible time planning

15. New beam pipe for pixel upgrade
CMS Technical Coordination requested in Nov 2010 a CAD design study for a beam pipe diameter that still would be compatible in installation and required clearances with 12 face innermost barrel layer.
BPIX design study finished in Jan. 2011
Considered:
cabling clearances
inner shield imperfections
beam displacements < 2 mm
minimal overlaps of sensor areas
Conclusion:
mean 1st layer Si- radius = mm
need 2 mm clearance to beam pipe
need adjustable closing mechanism
Beam pipe diameter (outer) = 45 mm !

16. BPIX & FPIX should both do these tests !
Installation: Adjust & Close Tests in LS1
Current BPIX design has 7.5mm tolerance from inner shield to beam pipe.
Observe ~3.2mm beam pipe displacement to nominal CMS tracker ! (z-dependent)
New upgrade pixel assumes courageous 2 mm tolerance gap to new beam pipe !
Only possible by adjustable BPIX pixel rail feet ! ( how about FPIX? )
Insertion past beam pipe support ring may require closing mechanism in final z-position !
Propose installation tests with duplicate of new upgrade pixel mechanics.
1) test tolerances
2) test adjustment to beam pipe displacement
3) test closing mechanism in situ
Talk about front end chip design – for upgraded system
BPIX & FPIX should both do these tests !
to be done ~ Mai 2014
worm gear

17. CO2-Cooling / Power Pixel Load Tests
PP0
Propose to build dummy supply tubes with ohmic power loads and CO2 cooling loops with identical power cabling and final cooling loop connections as real detector for PP0.
BPIX / FPIX service tubes with ohmic power loads and
CO2- cooling loops
Pixel power / cooling load cylinders are used to verify and commission CO2 cooling plant at the PixTIF and the cooling plant in CMS prior to the installation of the new pixel in CMS.
Talk about front end chip design – for upgraded system
Ohmic power loads with CO2-cooling.
can be shortened

18. Development of digital PSI46 ROC
Reduce data losses by:
1) increase depth of
- data buffer 32  80
- timestamps 12  24
2) add readout buffer
3) 160Mbit/sec serial binary data out
4) deal with PKAM events
Tests with LHC rate beams
- rare errors with data
- SEU errors
32 data buffers m
1176 m
Submission planned Sept. 2011
Talk about front end chip design – for upgraded system
12 time stamp buffers
252 m
Next data losses term after 1) & 2) is dc-reset loss, removal possible by use of an extra marker bit (*)
 modify data buffer logic !
Submission possible in 2012 !
(*) based on an idea by H-C. Kaestli (2010)

19. Submission of digital PSI46 ROC
Submission of new digital PSI46dig (September 2011)
Submission with 4 chips / recticle
Qty Name Properties
PSI46 present analog readout ROC, as used now in FPIX / BPIX
PSI46xdb analog readout ROC but with extended deeper data buffers
PSI46dig digital ROC, extended data buffers & ROC readout buffers
TBM etc TBM & faster ALT & various test chips
Submission of dc-reset loss corrected PSI46dig (possible 2012)
Submission with 4 chips / recticle
Qty Name Properties
PSI46dig digital ROC, extended data buffers & ROC readout buffers
PSI46digx PSI46dig with dc-reset losses removed
Talk about front end chip design – for upgraded system

20. Possible Recticle for September 2011 Submission
HDI-driver chip
Old PSI46 ROC
PSI46xdb
- analog readout
- extended db & ts
buffers
LCDS-driver chip
( Kapton cable drivers)
old TBM
TBM chips
PSI46dig
- digital readout
- extended db & ts
buffers
- readout buffers
- pulse height ADC
old & PKAM
clipping
redesigned
more test chips
ALT chip
( Faster Analog Level Translator (ALT) chip for read out Opto Hybrid)
digital TBM &
PKAM clipping

21. FPIX Pilot Blades with PSI46dig ROC
FPIX mechanics, cooling & cabling was originally designed for 3 disks each side.
Present installed FPIX system has only 2 disks equipped.
All cables, fibres and cooling pipes for 3rd disk exist !
Proposal:
After repair of present FPIX during LS1 insert the 3rd disk mechanic and mount a few pilot blades of old design with new digital ROC (PSI46dig) and provide for these blades a few (already existing) readout fibres with old AOH, but new (faster) ALT chip.
Talk about front end chip design – for upgraded system
Available time slot for construction
Jan Feb  13 month !
Can operate and commission new digital ROC under realistic conditions (use CMS tracking as beam telescope) and write all the necessary software changes in DAQ, DB and DQM for a smooth and swift transition for the new upgraded pixel system in 2016/17

22. PSI46xdb : analog ROC with extended data buffers
Present ROC with analog coded readout can be significantly improved for beyond LHC luminosity performance at very low radius layer by extended data & time stamp buffers
PSI46xdb included in combined recticle in planned September 2011 submission.
ROC becomes 356um larger  may use in fresh BPIX 1st layer replacement in LS1 !
1176 m
32 DB
576 m
12 TS
252 m
1532 m
80 DB
896 m
24 TS
288 m
356 m
present ROC
increased buffer size
compact layout (done)
Talk about front end chip design – for upgraded system

23. Replacement of 1st Layer of BPIX in SL1 ?
Replacement of 1st layer of BPIX with fresh silicon sensors and improved ROC chip with deeper data buffers could allow an efficient 1st BPIX layer operation for LHC running beyond standart luminosities.
Summer 2007, mounted modules of 1st pixel layer
Use of PSI46xdb ROC that is logic design step along the path to produce PSI46dig.
Available production time slot
Jan – Feb. 2013
 13 month
This would cure the dominant dead time producing mechanism (data buffer overflow) and improve the 1st layer data loss (~5%) until installation of the new upgraded 4 layer pixel system with digital readout. For readout and software nothing changes.
However, it will distract us from our main mission of a new 4 layer digital pixel system !

24. Data digital pixel module / balanced coding
MUX
core
ROC
160 MHz bus channel A
160 MHz bus channel B
320 MHz uplink
Token A
Token B
TBM
320 MHz read out signal is pseudo balanced by multiplexing by A with !B
 good enough for ZARLINK ?
 need encoding in TBM ?
which? 4b/5b or 8b/10b
core

25. New FPIX Pilot System for 2013
2011
2012
2013
2014
2015
2016
2017
2018
LHC machine
7 TeV TS
7 TeV
shut down LS1
14 TeV TS
14 TeV TS
14 TeV TS
14 TeV
LS2
CMS open
( )
( )
( )
present beampipe
new beampipe (45mm)
FPIX Pilot
Pixel (rep/ mod/ test/ inst)
constructon
new pixel instal. test
PP1 preparation
Pixel PixTIF
CO2 plant (pre) install.
( )
CO2 – pixel load tests
Pixel (instal./comm./oper)
Pilot blades with PSI46dig for 3rd FPIX Disk: Jan 2012 – Feb  13 months ! !

26. Summary & Conclusions
Chamonix 2011 schedule for LHC has clear constraints for next years to come and the work that needs to be done in LS1.
Schedule for LS2 not reliable known. Installation in extended TS (2016/17) conceivable.
Should advance as many pixel installation jobs as possible to LS1.
 reduce personal irrad. dose; more time to react for problems; reduce task pile-up
Beam pipe (outer) diameter of 45mm would allow 1st pixel layer radius <r>= 29.8mm
Requires adjustabel feet to deal with clearance tolerances and disalignment of CMS
ROC submission planned in Sept with PSI46, PSI46xdb, PSI46dig & TBM’s plus extra chips like faster ALT, Gatekeeper etc.
Propose to install in LS1 the FPIX system with partial equipped 3rd disks using a few pilot blades with the new digital ROC and digital readout chain. Allows concurrent running and commissioning of old & new system. Time slot for construction is very short. (~1 year)
Common System & Integration (CSI) coordination is a very big task and linked to TC!

27. Spare Slides

28. CSI: Common Systems & Integration (1)
Pixel CSI Coordinator will have to organize and do many things:
Beam-pipe planning, installation and taking care of all interface issues with the pixel detector (old & new) during Long Shutdown LS1 ~ 2013/14)
Test installation during LS1 of pixel upgrade mechanics (adjustment & closing) with new beam pipe. Installation platforms, adjustment tools, inspection tools, clearance sensing & control to beam pipe in conjunction with the FPIX & BPIX groups
Organization & Operations of Pixel Repair Lab at Point5 (dual use old / new pixel)
Conceive, prepare, organize and get done with all required changes to services in PP1 / PP0 during LS1 that can be  advanced from period in 2016/17. Stay operational with old system till installation of the upgrade pixel detector.
CO2 Cooling plant: - basic conception, plant design & construction,
- piping & sensors for open loop sensing or feed back
- control software and interlocks
Pixel test facility at TIF (PixTIF): Conception, build up and operation of pixel test facility with correct length piping and CO2 cooling plant  test pixel system

29. CSI: Common Systems & Integration (2)
Establishing & Coordination of DAQ / Power & Slow Control for complete system tests at PixTIF
Shielding & radiation dose management of working people during LS1 & Installation
 feed back to project planning (dose spreading limits, show stopper ?)
In situ power load & CO2 cooling tests with ohmic loads on installed service tube dummies and final PP0 LV-cabling & CO2-piping. Design & fabrication of dummy service tubes with ohmic loads for FPIX & BPIX.
Take care and organize pixel common items:
- CAEN power supplies: firmware changes (2015), planning new units for 2018)
- environmental control (humidity control during installation, etc. etc. )
- Optical link components, qualification & production of POH
- Pixel FED: adaptation to serial protocol, board-production, etc.
Installation of new upgrade pixel system in 2016 / 2017
Prepare Software adaptation for switch over: old pixel  new pixel in 2017