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

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

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

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

Matching VD and VTPC - introduction

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

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

Influence of cuts VTPC2 VTPC1

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 https://indico.cern.ch/conferenceDisplay.py?confId=181349 (Collaboration meeting in Budapest 2012)

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.

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

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

vertical layout – front view VTPC2

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

VTPC2 VTPC1

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

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 2014 - January 2015 8. Integrated test for Ar+Ca: Feb. 2015 (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)

Backup Slides

vertical layout – top view VTPC2

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

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

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

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

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

Decay topology and definition of cuts

Distribution of pT, d, Vz and D variables