1. Vertex Detector project for the NA61/SHINE collaboration
Pawel Staszel
ALICE - NA61/SHINE meeting, CERN, March 6, 2014

2. Outline 1. Setup geometry (full version). 2. Feasibility studies
VTPC2
1. Setup geometry (full version).
2. Feasibility studies
3. Start version VD geometry
4. Concept of mechanical support and mechanical movement
5. Project plan

3. NA61/SHINE detector – top view
VTPC2
Vertex Detector (VD)

4. VD in geant4 Vessel: VDS1 : 5 cm VDS2: 10 cm VDS3: 15 cm VDS4: 20 cm
target
VTPC2
VDS1 : 5 cm
VDS2: 10 cm
VDS3: 15 cm
VDS4: 20 cm
VTPC1
Vessel:
Rectangular left/right plates
Trapezoidal top/bottom plates
→ same length of carbon ladder
→ similar distance between left/right plates and VDS1-VDS4
→ Flex Print Cables variation in length +/- 4cm

5. Matching VD and VTPC - introduction

6. Study of central Pb+Pb at 158A GeV
VTPC2
VTPC1
Initial background much bigger than signal form D0 →needs to apply background suppression cuts.

7. Background suppression strategy
List of cuts in the order they are applied
Single particle cuts:
1. cut on the track transverse momentum pT
2. cut on the track impact parameter d
Two particle cuts:
3. cut on two track vertex longitudinal position Vz
4. cut on reconstructed parent impact parameter D

8. Influence of cuts
VTPC2
VTPC1

9. Simulation results: full version of VD
200k 0-10% central Pb+Pb at 158 GeV
VTPC2
VTPC1
With perfect PID:
S/B=17
for 50M events:
~ 64k D0 + D0bar
SNR= 246
With perfect PID:
S/B=1
for 50M events:
~ 64k D0 + D0bar
SNR= 197
more analysis details at
(Collaboration meeting in Budapest 2012)

10. MIMOSA-26
The following conceptual drawings are based on MIMOSA-26 chip hosting sensitive area of about 1.06 x 2.12 cm2 with the pixel pitch equal 18.4 μm (~663.5k pixels/chip):
VTPC2
These pads are for testing purpose and can be removed
VTPC1
The readout speed of the whole fame in ~100 μs (10 kHz), zero suppression circuit.
The chips are available.

11. Sensor layout for start version
VTPC1
10 ladders are needed with length of ~ 30 cm.
Ladders are mounted vertically.
About 35% of the final acceptance (for D0)
First measurements for physics

12. VD in geant4 (vertical layout)
VTPC2
target
VTPC1
Foreseen horizontal movement of the hole device between out and in positions.

13. vertical layout – front view
VTPC2

14. Ladders, strong and weak points
Current concept reminder
+ Outstandingly low material budget
+ Perfect cooling power
+ Highly integrated device
- Width only 15mm
- Problems with thermal expansion
Ladder is bent at room temperature
Bending radius temperature dependent
Because of the horizontal orientation and installation on mechanically stable frame we may not need triangular structure
→ dedicated development will me simplified
We need width of 22 mm 14

15. VTPC2
VTPC1

16. Integration Option A – Move Sensor Sensor Cable 50µm 5mm
Collin issues might be solved but:
Extremely fragile
=> R&D + extremely high risk
Option B – Extend ladder
Option C – Extend place on a ladder
Sensor
Cable
Cable
=> R&D + costs + manpower
Solved integration issues but:
Needs new tooling
Eventually new R&D
In any case: Bonding has to be demonstrated,
might need dedicated tools 16

17. Time plan 1. Proposal submitted (3 years) (done)
2. Funds (if) available in May 2014 (2 months)
3. Purchase of 12 MIMOSA-12 sensors, March 2014 – expect delivery to IKF (~week)
4. Purchases (LV, Water Cooling Plant, TRB) June-July 2014
5. Hardware work in parallel:
i) carbon fiber support (CERN, Grigory, Sergiey) ( Aug 2014?)
ii) sensors quality checks (IKF Frankfurt, Michael, Michal) (July 2014)
iii) integration on support (IKF Frankfurt, Michael, Michal) (late 2014)
iv) mock-up, mechanical movement, cooling system (Krakow, Pawel, Tadeusz, Ludomir) (April-late 2014)
v) adopting read-out to NA61, Grzegorz Korcyl - working with TRBv3 for HADES, Oskar, (April-Nov 2014)
vi) Upgrade NA61 Daq (Nov-Dec 2014), Andras
6. Integration of the system and tests on cosmics with DC (in Krakow) → will allow for synchronization test (Dec 2014 – Jan 2015)
7. Preparation for test at CERN: Nov January 2015
8. Integrated test for Ar+Ca: Feb (is it feasible? - at least we can try)
9. Next test in Dec 2015 – on Pb+Pb
10. Nov-Dec 2016 physics program on Pb+Pb at 2 energies (150A and 70A GeV/c)

18. Backup Slides

19. vertical layout – top view
VTPC2

20. Cooling system Flow direction VTPC2 Distribution manifold
Slow control unit
Distribution manifold
Flow-meter/controller
VTPC1
Cooling
plant
Temperature sensors
Vessel plates (left/right)
Flow direction
Flow: 1000cm3 / min to keep ΔT=1K

21. Cooling system Prototype: 12 pipes, full detector: 40 pipes
VTPC2
Slow control unit
Flow-meter/controller
Distribution manifold
VTPC1
Cooling
plant
Prototype: 12 pipes, full detector: 40 pipes
Flow direction

22. Cooling system Elements fixed to the vessel → moving together VTPC2
Slow control unit
Distribution manifold
Flow-meter/controller
VTPC1
Cooling
plant
Elements fixed to the vessel → moving together

23. Readout system (more in Michael's talk)
VTPC2
Should be available soon → developed for CBM, we might profit from this development
VTPC1

24. Readout system Aluminum frame VTPC2
Primary setup handles 2 sensors, it might fit well to full VD setup
VTPC1
Aluminum frame

25. Decay topology and definition of cuts

26. Distribution of pT, d, Vz and D variables