Building ALICE for heavy-ion physics at LHC

1. Building ALICEfor heavy-ion physics atLHC • Slovak participation in ALICE • Contribution of Košice team Ladislav Šándor Slovak Academy of Science Institute of Experimental Physics Košice L. Šándor, IEP SAS, Košice

2. Why Slovak involvement in ALICE ? • Active work of Slovak physicists (both experimentalists and theorists) in heavy-ion physics for more then a decade • Fruitful experience from a number of SPS experiments (NA34-Helios, WA97, NA49, NA57) • Unique potential of ALICE – the only dedicated heavy-ion experiment at LHC – for A-A, p-A and also p-p physics attracting interest of qualified teams from Bratislava and Košice to continue working in heavy-ion physics L. Šándor, IEP SAS, Košice

3. 1200 TDR ALICE 1000 Collaboration statistics 800 MoU 600 TP 400 200 LoI 0 1990 1992 1994 1996 1998 2000 2002 2004 ALICEcollaboration ~ 25 Slovak physicists and engineers 937 members (63% from CERN MS) 77 institutions 29 countries L. Šándor, IEP SAS, Košice

4. ALICE physics goals • Global observables: Multiplicities,  distributions • Degrees of freedom as a function • of T: hadron ratios and spectra, dilepton continuum, direct photons • Early state manifestation of collective effects:elliptic flow • Energy loss of partons in quark gluon plasma: jet quenching, high pt spectra, open charm and open beauty • Deconfinement: charmonium and bottonium spectroscopy • Chiral symmetry restoration: neutral to charged ratios, res. decays • Fluctuation phenomena - critical behavior: event-by-event particle comp. and spectra • Geometry of the emitting source: HBT, impact parameter via zero-degree energy flow • pp collisions in a new energy domain • Selective triggering • Excellent granularity • Large acceptance • Good tracking capabilities • Wide momentum coverage • PID of hadrons and leptons • Good secondary vertex reconstruction • Photon detection Use a variety of experimental techniques ! L. Šándor, IEP SAS, Košice

5. TPC Tracking, dEdx ITS Low pt tracking Vertexing The ALICE experiment L. Šándor, IEP SAS, Košice

6. Comenius University Bratislava (see talk by B. Sitár) read-out chambers for the TPC detector pixel testing set-up, SPD on-line software IEP SAS and Šafárik University Košice electronics for silicon pixel detector electronics for central trigger unit physics simulations Slovak contribution to ALICE Total CORE commitment: 700 kCHF L. Šándor, IEP SAS, Košice

7. Košice ALICE team activities • Contribution to the Silicon Pixel Detector (SPD) electronics • Contribution to the central trigger electronicsand software • Simulations of the radiation situation in ALICE environment • Physics simulations, analysis tools development (new, just starting activity) Košice team: 12 physicists and engineers from Institute of Experimental Physics, SAS and Physics Institute of P.J. Šafárik University Laboratory for design and development of electronics built at the IEP SAS (Quartus & PADS software, 6U/9U VME crate, …) L. Šándor, IEP SAS, Košice

8. 2 strips 2 drifts The Inner Tracking System(ITS) Silicon Pixel Detector 2 pixels Rout=43.6 cm The ALICE SPD ALICE • Two SPD layers at • r= 3.9 & 7.6 cm • Structured to 60 staves • containing 9.8 M active • pixel channels • Magnetic field < 0.5 T • Charged particle multiplicity • up to 8000 per rapidity unit • in central Pb-Pb collisions L. Šándor, IEP SAS, Košice

9. SPD readout architecture DCS DAQ VME Router Card PCI-MXI-II-VME JTAG, CLK, Detector Data Trig ~100m 1 router services 6 halfstaves SPD contains 20 router boards Košice commitment (J. Bán, M. Krivda) L. Šándor, IEP SAS, Košice

10. Main tasks of SPD Router • Receive trigger signals from the Local Trigger Unit (L0 - only for synchronization, L1, L2Y, L2N) and send them to detector • Send busy signal to ALICE trigger and DAQ • Read-out data from 6 half staves ( after receiving L2Y ) • Assert the flag “flush event” (no read-out) after receiving L2N • Check errors and store them in status register accessible from VME (DCS) • Merge data to one block with a defined ALICE data header • Send data to DAQ • Extract data flowing to DAQ and store them to SPY memory available for analysis via VME (for debugging purposes) • Automatic configuration of SPD after power up • Autocalibration of SPD • Processing power available to run complex algorithm (future) L. Šándor, IEP SAS, Košice

11. SPD Router architecture • 9U-VME board with mezzanine boards • 3 Link receivers on mezzanine board (6 half staves) • TTC Rx chip (BGA package) soldered on board – interface to ALICE trigger • SIU DDL module on mezzanine board – interface to ALICE DAQ • JTAG controller with 6 ports (half staves) • SPY controller and memory for sampling DAQ data • SPY memory (external big dual port RAM) for debugging purposes and calibration data • Parallel synchronous bus (32 bit data, 21 bit address, control lines) • All controllers implement I/O buffers in one FPGA L. Šándor, IEP SAS, Košice

12. Router architecture – data flow ALICE Trigger DAQ Router controller TTC rx DDL Clock distribution DCS VME bus Link receiver 1 SPY memory Link receiver 2 Optical links of detector SPY controller JTAG controller Link receiver 3 Data (32) Address (21) L. Šándor, IEP SAS, Košice

13. SPD router board prototype • First router board prototype (designed by M. Krivda in co-operation with CERN team) has been produced at CERN,now undergoing testing • Complex tests of router prototype functionality during the forthcoming SPD testbeam run (October 2004) • Production of the second prototype in Slovak industry (end 2004 / beginning 2005) L. Šándor, IEP SAS, Košice

14. JTAG controller card • Fully functional part of the router produced as a stand-alone card for pixel testing set-ups • 6U VME board with 4 JTAG channels • control of data processing with macroinstructions • very complex design fittingspecific ALICE requirements with possibility to implement new algorithms in future • 24 JTAG controllers produced in Slovak industry for usage in testing set-ups at CERN, Italian and Slovak laboratories Used in test setups of pixel chip for: • configuration and testing of pixel chip registers • control and monitoring of test setup environment L. Šándor, IEP SAS, Košice

15. JTAG controller L. Šándor, IEP SAS, Košice

16. Pixel test system components JTAG Controller VME Master R/O Controller Pixel Chip Pixel Carrier DAQ Adapter L. Šándor, IEP SAS, Košice

17. ALICE trigger development • Close collaboration with the University of Birmingham • Design and prototyping the TTCit (Trigger Timing and Control interface test) board – an optional debugging and monitoring tool at the level of the subdetector TTC partition (S. Fedor) • Development of corresponding monitoring software (I. Králik) • Design and implementation of the CTP online software (A. Jusko, now at Birmingham) • Participation in design and production of a part of the CTP hardware (future) L. Šándor, IEP SAS, Košice

18. TTCit board • 6U-VME board • Dedicated L0 input in LVDS format • Single TTC optical channel • Reprogrammable TTCit logic via VME bus • Oscilloscope access to FPGA and TTCrx signals • Design in final stage • Review of design in October • First prototype end 2004 L. Šándor, IEP SAS, Košice

19. Radiation levels in ALICE The ALICE design parameters together with running plans (collision systems, luminosity, running time) determine the radiation load. Order of magitude of the problem: • 4 x 1015 particles produced in all planned primary collisions (6 x 1014 particles in Pb-Pb interactions) • 2 x 1014 particles are produced in beam-gas collisions inside the ALICE experimental area (IP +/- 20 m) • 8 x 1014 particles enter ALICE environment as a beam-halo Detailed knowledge of radiation level important for optimization of detector and electronics design L. Šándor, IEP SAS, Košice

20. Simulations • Detailed estimate of the radiation level can only be obtained from simulations using transport codes • Input primary particles simulated with HIJING, Pythia, DPMJET and boundary source for beam halo • Transport code: FLUKA • Scaling of results performed for 10 years running scenario of ALICE Simulations of the radiation level in ALICE – commitment of Košice team from 1998 (principal investigator - B. Pastirčák) • Large-scale amount of simulations performed resulting in : • optimisation of radiation level in the muon and trigger chambers leading to proposal of a shielding (small angle absorber) in the ALICE muon arm • global calculation of radiation level in all subdetectors (including electronics racks) assuming 10 years of ALICE operation L. Šándor, IEP SAS, Košice

21. Dosesandneutronfluences in mid-rapidity ALICE detectors For more details see ALICE internal publications L. Šándor, IEP SAS, Košice

22. Neutron fluence map z (cm) L. Šándor, IEP SAS, Košice

23. Dose map (Gy) z (cm) L. Šándor, IEP SAS, Košice

24. Charged hadrons fluence map z (cm) L. Šándor, IEP SAS, Košice

25. Lessons from simulations … • Primary physics collisions in the IP are the dominant source of radiation load. However, with more pessimistic assumptions on residual gas pressure the beam-gas contribution could be of equal order of magnitude • Highest doses (several kGy) are reached in the inner SPD layer and at the inner radii of forward detectors (FMD, V0, T0) • Hadron fluences are up to 4 x 1012 cm-2 (SPD1) • The highest doses in the electronic racks are on the level of 10 mGy with n-fluences up to 109 cm-2 • Radiation simulations now practically completed and the results were utilitized at different stages of detector and electronics design and prototyping L. Šándor, IEP SAS, Košice