1. Trigger system for the T600 detector: applications to Supernova detection G. Fiorillo for the ICARUS Collaboration CRYODET Workshop LNGS, March 13-14, 2006

2. G. Fiorillo Cryodet Workshop, LNGS 13 March 20062 View of the inner detector T600 semimodule Cryostat (half-module) Readout electronics

3. G. Fiorillo Cryodet Workshop, LNGS 13 March 20063 ICARUS DAQ

4. G. Fiorillo Cryodet Workshop, LNGS 13 March 20064 Physics considerations Events in T600 at LNGS: –Cosmic rays muons –Atmospheric neutrinos –Solar neutrinos + neutrons  E ~ 5 MeV –Neutrinos from Supernova (burst)  E ~ 20 MeV –Proton decay –CNGS neutrinos  external timing –Beam muons

5. G. Fiorillo Cryodet Workshop, LNGS 13 March 20065 Event topologies Cosmic-ray shower Muon Low energy electrons

6. G. Fiorillo Cryodet Workshop, LNGS 13 March 20066 Data volume (A. Rubbia ICARUS IM Sept.02) –1.5 m drift or 1 ms is 2500 samples of 400 ns –27130 wires with 2500 drift samples –32 wires per board x 18 boards per crate x 48 crates= 27648 readout channels of 2500 samples Total volume: 260 TB per year (25% CMS or ATLAS experiment!) Volumes are dominated by physics backgrounds: neutron capture and muon crossing

7. G. Fiorillo Cryodet Workshop, LNGS 13 March 20067 Neutrinos from Supernovae Elastic scattering from neutrinos (ES) Electron-neutrino absorption (CC) Elastic scattering from antineutrinos (ES) Electron-antineutrino absorption (CC)  ( e )+0.15  (  +  )  ( e ) Q=5.885 MeV  ( e )+0.34  (  +  )  ( e ) Q≈8 MeV low energy reactions in Argon

8. G. Fiorillo Cryodet Workshop, LNGS 13 March 20068 Shock breakout collapse Oscillation No oscillation 757 730 27 Non adiabatic 1036 995 41 Adiabatic Expected events from SN at 10 kpc in 3 kton 244 TOTAL 203 absorption 41 Elastic reaction A.Rubbia, I.Gil-Botella

9. G. Fiorillo Cryodet Workshop, LNGS 13 March 20069 Supernova burst Specific time structure –Ex.: ~ 100 SN triggers in T300 in 1 sec (expected for a SN at 10 kpc, with an energy release of 10 53 erg) Global trigger (full detector readout): bandwidth + storage problem –1 event = 27648 ch  2500 samples  2 bytes ~ 130 MB  13 GB total –DAQ throughput limit: 5 minutes to empty buffers) Local trigger: SN events are localized and limited to 1 crate per view –5 events per crate (on average) in COLL + IND2 views ~ 40 MB/crate –13 events per crate (on average) in IND1 view ~ 60 MB/crate  Each crate can be read-out as a separate event

10. G. Fiorillo Cryodet Workshop, LNGS 13 March 200610 Segmented trigger Intrinsic granularity of the trigger is a crate The requirement of the Supernova trigger introduces two types of triggers –Global triggers: an entire T300 is readout as a single event –Local triggers: the various crates are readout independently as separate events Overlapping in time local triggers can be reconstructed offline (or online) using the absolute time information The implementation of local triggers presupposes the development of a small “local trigger control unit” card in each crate

11. G. Fiorillo Cryodet Workshop, LNGS 13 March 200611 Segmented trigger pixel definition Rack 1 Rack 20 Rack 11Rack 13 T600 Half Module – 1 chamber viewed from cathode 1 pixel area: ~ 0.6 m 2 Total Number of Pixels ~ 80 32 x 9 Induction II wires 32 x 9 Collection wires 864 mm

12. G. Fiorillo Cryodet Workshop, LNGS 13 March 200612 MC simulation: low energy events ICAFLUKA

13. G. Fiorillo Cryodet Workshop, LNGS 13 March 200613 MC simulation: high energy events ICAFLUKA

14. G. Fiorillo Cryodet Workshop, LNGS 13 March 200614 Preliminary considerations Trigger rate is dominated by physics background –Neutron capture rates expected in T600 (ICARUS/TM- 2002/13) : 2  10 -4 s -1 from natural radioactivity of the rock 0.03  0.1 s -1 from Al container Segmented trigger potentially solves bandwidth and storage problems Event pre-classification  data streams –extraction of solar neutrino data from low energy stream Test bed for larger LAr detector low energy trigger

15. G. Fiorillo Cryodet Workshop, LNGS 13 March 200615 Trigger Input PMTs (global and local triggers) DAEDALUS (Based on single wire information) AWS (Analog 32 wires sum, exists on the front- panel of each analogue card, local triggers) External (beam profile chambers, cern-spill, …global)

16. G. Fiorillo Cryodet Workshop, LNGS 13 March 200616 [x 50 ns] PMT signal The high light yield measured in T600 provides the natural solution for T 0 definition and (in part) for trigger PMT system

17. G. Fiorillo Cryodet Workshop, LNGS 13 March 200617 A PMT based trigger The PMT system allows for the design of a fast triggering system able to select the events on the basis of the scintillation light produced in liquid argon. The study is based on the MC simulation of real events inside the T600 detector. The contribution due to the dark counts and noise is taken into account. The segmentation of the sensitive volume according to the PMT layout permits the definition of local triggers.

18. G. Fiorillo Cryodet Workshop, LNGS 13 March 200618 Trigger Efficiency Plots The plot summarizes the trigger efficiency (triples case) as a function of the electron kinetic energy, for different threshold values (G.Raselli IM Jan06).

19. G. Fiorillo Cryodet Workshop, LNGS 13 March 200619 Trigger Efficiency Tables 10 7 0.51.5 5 2 15 3 31 Threshold (phe) Energy (MeV) 98.3% 6.2 Hz Trigger efficiency / Stochastic rate (triples case) 99.7% 99.9% 95.2% 99.1% 99.8% 99.9% 86.1% 97.9%99.1% 99.8% 99.9% 73.6% 93.3%97.1% 99.4% 99.9% 46.2% 80.2% 92.8% 97.9% 99.6% 6.2 Hz 1.1 Hz 0.2 Hz <0.1 Hz «0.1 Hz

20. G. Fiorillo Cryodet Workshop, LNGS 13 March 200620 Basic design requirements Redundancy important to measure efficiency Global trigger: –Generated by PMTs or external –drift deadtime GLOBAL_DRIFT (1ms) –Read-out deadtime GLOBAL_BUSY (1s) vetoes new global triggers –Local triggers vetoed during GLOBAL_DRIFT Local trigger: –Generated by AWS + PMT –LOCAL_DRIFT (1ms) vetoes new local triggers

21. G. Fiorillo Cryodet Workshop, LNGS 13 March 200621 Trigger System Architecture l LTCU: discriminates the inputs, has one independent threshold for each input, gives 1st level trigger proposals as output; l TCU: performs coincidences between LTCUs proposals, processes the fired pixels to study and label the event topology, produces global or local trigger proposals; l Trigger Supervisor: monitoring of the trigger and the DAQ system, statistical functions.

22. G. Fiorillo Cryodet Workshop, LNGS 13 March 200622 Trigger System Architecture LTCUTCU TRIGGER SUPERVISOR DAQ CERN or any other external request 20 boards per chamber (80 boards for T600)  from v791 n-bit request v816 96 9 4 boards per T600 9 Trigger Distribution T 1 20 T 2 20 T11T11 T21T21 PMT LTCU

23. G. Fiorillo Cryodet Workshop, LNGS 13 March 200623 LTCU discriminates the 18 inputs comparing them with remotely controlled thresholds. Noisy inputs can be masked Gives as output two separate trigger proposals (T 1 and T 2 ), corresponding to the OR of INDII or COLL boards respectively Test mode to check the working status Counting capabilities to check rates of trigger proposals for each input Board functionalities are driven by a remote controller TCU LTCU 9 T1T1 T2T2 9  from v791 1 board per crate - 20 boards per chamber each board receives as input 9 + 9  coming from the v791 analog boards (generally 9 of 2nd induction and 9 of collection) 1st trigger level: LTCU

24. G. Fiorillo Cryodet Workshop, LNGS 13 March 200624 1 board per chamber VME standard each board receives as input 40 signals from the AWS LTCUs (2 T signals x 20 boards) and N signals from PMT LTCU TCU performs coincidences between: the wire planes (in a ~3  s time window), the PMT signals, the external requests checks Majority, Minority, 2D Pattern logic conditions event is labelled according to topology An n-bit-word trigger request is sent to the Trigger Supervisor, defining the fired crates 2nd trigger level: TCU CERN or any other external request TS T11T11 LTCU TCU T 1 20 T 2 20 T21T21 n-bit request PMT LTCU AWS

25. G. Fiorillo Cryodet Workshop, LNGS 13 March 200625 TRIGGER SUPERVISOR DAQ n-bit request v816 96 Trigger Distribution 1 or more boards VME standard TS receives 4 input n-bit-words from the TCU and the ABS CLOCK TS evaluates if the trigger request from TCU corresponds to a Local Trigger or a Global Trigger TCU Monitoring of the system and validation of Trigger requests. GLOBAL/LOCAL DRIFT/BUSY Logic Trigger signal distribution to the v816 Event trigger tag (trigger number, time, type, acquisition dead time…) Statistics for the trigger system ABS CLOCK Trigger Supervisor

26. G. Fiorillo Cryodet Workshop, LNGS 13 March 200626 TS GLOBAL/LOCAL Logic Trigger classification depends on: Energy deposition/number of PMT fired. Detector occupancy 2D/3D Pattern of fired pixels TS gives GLOBAL trigger when a MAJORITY condition is met in PMT logic Otherwise the trigger is LOCAL

27. G. Fiorillo Cryodet Workshop, LNGS 13 March 200627 GLOBAL/LOCAL trigger BUSY logic After validation of a global trigger request TS gives the GLOBAL_DRIFT signal to all v789 boards During a GLOBAL_DRIFT, TS doesn’t accept any other trigger request, while, during a GLOBAL_BUSY (DAQ dead time for acquisition data download from all chambers) it accepts only a Local Trigger request During LOCAL_DRIFT it doesn’t accept any other trigger request in the same crate

28. G. Fiorillo Cryodet Workshop, LNGS 13 March 200628 The trigger generation algorithm

29. G. Fiorillo Cryodet Workshop, LNGS 13 March 200629 Time Diagram PMT Induction II  signal Collection  signal LTCU T 1 signal LTCU T 2 signal TCU Trigger request TS Trigger signal  T  3  s  T  1.5 ms Trigger dead time n-bit

30. G. Fiorillo Cryodet Workshop, LNGS 13 March 200630 FPGA Input stage RS232 interface 10 MHz oscillator Power supply 18 inputs Trigger outputs DAC The LTCU prototype v1.0 IN V DAC Discriminator Voltage follower RC filter OUT IN

31. G. Fiorillo Cryodet Workshop, LNGS 13 March 200631 VME INTERFACE Xilinx Spartan XC2S100 INPUT STAGE Xilinx Spartan XC2S100SYNCHRONOUS FIFO IDT72V263 80 programmable input / output 2nd level Prototype TCU

32. G. Fiorillo Cryodet Workshop, LNGS 13 March 200632 Summary The readout of SN events, due to their burst nature, requires the implementation of local triggers to overcome data volume problems The segmentation of the sensitive volume permits the definition of local triggers potentially solving bandwidth and storage problems Event pre-classification by the trigger allows for the definition of data streams (useful for the analysis) Redundancy in the trigger system is important in order to measure the efficiencies ÙSegmented Trigger architecture based on PMTs and Wires ÙGlobal trigger: the full detector is read-out as a single event ÙLocal trigger: only active “pixels” are read-out as separate events ÙEvents are labelled according to pixel topology

33. G. Fiorillo Cryodet Workshop, LNGS 13 March 200633 LTCU prototype for AWS v1.0

34. G. Fiorillo Cryodet Workshop, LNGS 13 March 200634 LTCU v1.0

35. G. Fiorillo Cryodet Workshop, LNGS 13 March 200635 The LTCU functionalities v1.8i Mask the input channels; Read the mask status; Set the thresholds; Monitor the trigger rate for each input; Discriminator test mode; Select one discriminator output put on front panel. All the board functionalities are remotely controlled via RS232 interface.

36. G. Fiorillo Cryodet Workshop, LNGS 13 March 200636 V1.0 test on 50 liters LAr TPC

37. G. Fiorillo Cryodet Workshop, LNGS 13 March 200637 Trigger rate test chain LTCU inputs = 4  signals from collection plane; Trigger generated from only one  input (no FastOR); LTCU trigger output distributed to V816 module. LTCU Trigger OUT V789 LTCU  V791 IndColl IN OUT IN OUT IN Analog  OUT V816 trigger PC (RS232)

38. G. Fiorillo Cryodet Workshop, LNGS 13 March 200638 Trigger Rate Plateau (I) Plateau zones

39. G. Fiorillo Cryodet Workshop, LNGS 13 March 200639 Trigger Rate Plateau (II) Plateau zones

40. G. Fiorillo Cryodet Workshop, LNGS 13 March 200640 Trigger efficiency test chain LTCU inputs = 4  signals from collection plane; One LTCU IN and Trigger OUT digitalized by a modified V791; PMT trigger distributed to V816 module. PMT V789 LTCU  V791 IndColl IN OUT IN OUT IN Analog  OUT V816 trigger PC (RS232) OUT IN Modified V791

41. G. Fiorillo Cryodet Workshop, LNGS 13 March 200641 Test Results ProblemsSolutions High frequency noise on input signal Band-pass filter ( f -3dB H = 2 MHz, f -3dB L = 1 kHz ); Offset for negative input isn’t a stable solution Inverter amplifier (G=1) in the input stage; More than 20mV white noise New pcb (with 8 layers) and EM/RF screening Not stable DAC threshold Stable V REF circuit

42. G. Fiorillo Cryodet Workshop, LNGS 13 March 200642 LTCU prototype v2.0 Power supply an filter Input stage (for one channel) or IN Band-pass filterSelectable inverter (G=1) V Test V TH OUT IN V TH DAC (for one channel) V REF V REF for DAC Filter for low noise performance Stable 259mV tension circuit V REF EM/RF Screening for input stage

43. G. Fiorillo Cryodet Workshop, LNGS 13 March 200643 PWR and GND distribution for LTCU v2.0 ±5A, AGND (V791 preamp. stage) +5A1, AGND1 (V791 mux stage) VCC, DGND (V791 digital stage) Four GND and two PWR planes

44. The second trigger level Trigger Control Unit Preliminary design

45. G. Fiorillo Cryodet Workshop, LNGS 13 March 200645 TCU Features ≥1 boards per chamber (depending on segmentation) VME standard checks Majority, 2D/3D Pattern logic conditions event is labelled according to topology Each TCU module receives as input – N aws signals from the 20 AWS-LTCU boards of a chamber – N pmt signals from PMT-LTCU – N ext from external (spectrometers, beam,...) TCU performs coincidences between: – The wire planes (in a 3  s time windows) – PMT signals – External requests

46. G. Fiorillo Cryodet Workshop, LNGS 13 March 200646 Pattern Recognition Need to store the evolution in time of the number of fired pixel A long track fires consecutive pixels (at different times) according to direction. In this case the event is global  can be acquired as many local events. In case of a Supernova burst several pixels could be fired with a big spacing in position and in time.

47. G. Fiorillo Cryodet Workshop, LNGS 13 March 200647 General Idea on Partial majority Rack 11Rack 13 Window runs over the detector Majority condition is checked for each window

48. G. Fiorillo Cryodet Workshop, LNGS 13 March 200648 General scheme of TCU

49. G. Fiorillo Cryodet Workshop, LNGS 13 March 200649 WiRe coincidences FPGA Features The detector is subdivided in four sections Each section is monitored by a different WR- FPGA Each WR-FPGA –Makes coincidences between wires of different directions –Checks the occupancy of the section –Detects spots, tracks.

50. G. Fiorillo Cryodet Workshop, LNGS 13 March 200650 PMT FPGA Features receives an N bit Word which defines PMT status makes concidences between PMT and wires makes global trigger proposals VME interface Features Directly interfaced to VME CPU. Establishes communication between VME and the rest of the board.

51. G. Fiorillo Cryodet Workshop, LNGS 13 March 200651 Wire Coincidences FPGA preliminary SYNC BLK SYNC BLK AND BLK 9 13 INA INB MASK 9 13 MASK 9 AA BB 13 A0_B[4:0] A1_B[5:1] A2_B[6:2] A3_B[7:3] A4_B[8:4] A5_B[9:5] A6_B[10:6] A7_B[11:7] A8_B[12:8] FLASH ADR[4:0] ENC REG_A REG_B REG_C SUM BLK VTH Internal Xilinx Memory Whole Carpet Majority ENCA ENCA2 ENCA3 MJLOCAL MJGLOBAL ADDRESS GENERATOR FLASH CLK PIPELINE

52. G. Fiorillo Cryodet Workshop, LNGS 13 March 200652 A possible implementation: the Uniboard ICC MASTER ICC SLAVE1 ICC SLAVE2 ICC SLAVE3 Spartan II FAUX Spartan II VME (J2) Spartan II VME (J1) Spartan II 333 FIFO A FIFO B FIFO A FIFO B FIFO A FIFO B FIFO A FIFO B 18 FF EF

53. G. Fiorillo Cryodet Workshop, LNGS 13 March 200653 UNIBOARD