Scalable TriDAS for the NEMO Project

Transcription

1 Monte Porzio Catone, Villa Mondragone 14/05/2009 Scalable TriDAS for the NEMO Project Tommaso Chiarusi INFN Sez. Bologna & Phys. Dep. Univ. Bologna for the NEMO Collaboration

2 Talk overview Neutrino Telescope: just add water... all data to shore: challenging throughput TriDAS base concept From NEMO Ph.1 to the scalable km 3 TriDAS architecture

3 Atmospheric downgoing " Cherenkov light Upgoing "! " seabed depth > 3000 m Less atm. bkg. when deeper ( below 3000 m usl) Expected signal > atm. bkg. when E! >10 TeV!Telescope Vol > 1 km 3 for some evts/year! Many PMTs (> 5000)! complex experimental setup! NEMO location: CAPO 3400 m usl See Paolo Piatteli s talk in plenary session today 100 km NEMO Capo Passero Site

4 some km 3 detector possible layouts: Hexagonal Grid 90 Detection Units 80 PMTs / D.U PMTs Square Grid 81 Detection Units Det.Unit 80 PMTs / D.U PMTs total cable PJB-SJB cable SJB-DU

5 thetelescope One muon event (only muon hits shown, no background) is made of DETECTION UNITS 20 floors, with 4 10 PMTs each

6 Expected Optical Data sources bioluminescence depth!2500 m) upgoing neutrinos (atm. + signal) (50 day -1 / km 3 ) atmospheric muons ( Hz / km 3 ) 40 K decays (30 40 khz / p.e ) S.P.E. HIT SIZE: Hit PMT Info + Hit Time + Hit Charge + Hit Wave Form(samples) Hit samples Vs. pulse time on a 10 PMT with 0.5 p.e. thr. (NEMO Ph.1 data) S.P.E. wave form ( 16 samples = 16 Bytes) 28 Bytes

7 Expected Data Rates 10 PMT Data Rate Data Rate Data Rate Data Rate single rate per PMT per Floor * per D.U. ** per km 3 *** (khz) (Mbps) (Mbps) (Gbps) (Gbps) (bare 40 K) (NEMO Ph. 1) (present DAQ) (expanded DAQ ) * 4 PMT/ Floor ** 20 Floor/D.U. ** 100 D.U.

8 The TriDAS reduces the data rate by filtering the data stream bunched in Time Slice (TS). A TS contains all data from all ( or part of) the detector occurred in a given time interval (~ ms). WHAT IS SCALABLE? The TriDAS principal elements: - Trigger System Controller (TSC): monitors and serves the TriDAS - (1 GbE I/O) - Hit Managers (HM): receive optical data; prepare and distribute the TS to the TCPU - TriggerCPUs (TCPU): apply the trigger logics to the assigned TS and transfer the selected data to the EM; - Event Manager (EM): receives the triggered data from TCPUs and build the Post-Trigger events data file Atmospheric Muon Signal (@ 3000 m depth) assuming! - Rate µ atm:!! 100 Hz!!! - RateK40 :!! 300 khz!!! - N. PMTs:!! 8000! - Rec. time window:! 6 µs Post-Trigger data rate: 40 MBps Stored data /day 1 TB!!!! Upgoing Neutrino Signal assuming! - Rate! :!! < Hz!!! - RateK40 :!! 300 khz!!! - N. PMTs:!! 8000!! - Rec. time window:! 6 µs Post-Trigger data rate:! 2 kbps Stored data /day! 150 MB!!!!

9 Time slice and Barrel Shift Paradigm [refer to: M.F. Letheren, 1995 CERN School of Computing] HM 1 HM 2 HM 3 HM 1 HM 2 HM 3 DU-TS i, 1 DU-TS i, 2 DU-TS i, 3 TCPU 1 TCPU 2 TCPU 3 TCPU 1 TCPU 2 TCPU 3 HM 1 HM 2 HM 3 HM 1 HM 2 HM 3 Full TS i TCPU 1 TCPU 2 TCPU 3 TCPU 1 TCPU 2 TCPU 3 If a TCPU needs more time, just add one more!

10 TriDAS for NEMO Ph.1 The maximum throughput of the MiniTower was " 512 Mbps One Machine, the Master CPU, played all the rules: Floor 4 Hit Manager, Trigger, Event Manager Floor 3 Floor 2 PC Floor 1 DM - RC Linux PC Monitor Floor 1 CABLE CPU PC Floor 2 PC Floor 3 PC Floor 4 Gbit switch <70 MB/s < 70 MB/s Master CPU Windows Hard Disk Hard Disk

11 TriDAS for a first prototype Detection Unit with 16 Floors; expected through put " 2 Gbps Shore interfaces to: Floor 1 Floor 2 Floor 3 Floor 4 standard 1 GbEthernet Networking Floor 5 Floor 6 Floor 7 Floor 8 Floor 9 Floor 10 Floor 11 Floor 12 Floor 13 Floor 14 Floor 15 Floor 16

12 Possible Network infrastructure for km 3 TriDAS (90 D.U.)

13 Number of Available Clock Cycles per CPU per TS: R CPU S Hit N ACC = Drate HM#TCPU D rate HM#TCPU = 10 Gbps S Hit = 224 b R CPU = 3 GHz N ACC = 70 Estimed number of necessary TCPU: N TCPU =! K N C N PMT R CPU If the req. N C >N ACC N. of TCPUs N PMT =8000 N C =N ACC =70 60 (i.e. trigger algo. is slow) ADD TCPU! Single Rate on a PMT (khz)

14 Monitoring Via ControlHost: a Tag Controlled Data Dispatching [V. Maslenikov et al. CASPUR, TCPU Trigger Time Window transferred to EM Time Slices tranfser to TCPU events written and stored Dispatcher for TriDAS status Dispatcher for Physics Data

15 Multi purpose on-line Visualizer ( with D. Bonfigli - UniBo)

16 On(Off)-line Event Display ( with A. Riccardo - UniBo)

17 Conclusions all data to shore is a challenging BUT feasible strategy for km 3 underwater!- telescope; scalable TriDAS architecture suppliyng high data-stream (up to 500 Gbps) is possible and affordable with the present technology; The NEMO Collaboration is completing a scaled TriDAS for the prototype Detection Unit.

18 G. Priede et al., Deep-Sea Research I 55 (2008)