24/03/2011 P.-A. Loizeau – Univ. Heidelberg

The CBM Time of Flight wall

electronic readout chain

Pierre-Alain Loizeau PI – Uni Heidelberg

DPG 2011, Münster

HK55.3

The CBM Time of Flight wall electronic readout chain

2/10P.-A. Loizeau – Univ. Heidelberg – HK55.3, DPG 2011, Münster24/03/2011

2. The electronic chain demonstrator

1. CBM and ToF Wall electronics specifications

Conclusion & Outlook

3. Proton Test beam at COSY, Jülich

4. Analysis procedure

5. Performance: First preliminary results

The CBM Time of Flight wall electronic readout chain

3/10P.-A. Loizeau – Univ. Heidelberg – HK55.3, DPG 2011, Münster24/03/2011

• Number of channels: ~75k

• Full system time resolution: better than 80ps => 40ps for electronics

• Hit rate: <1 to 25 kHz/cm², => up to 200 kHz per electronic channel

• Free running readout

1. CBM and ToF Wall electronics specifications

The CBM Time of Flight wall electronic readout chain

4/10P.-A. Loizeau – Univ. Heidelberg – HK55.3, DPG 2011, Münster24/03/2011

• Clock System: CLOSY2 board and distribution tree (GSI)

• Pre- amplifier and discriminator: PADI III (GSI), ASIC with 4 channels

• Free-running digitizer: GET4 (GSI), ASIC with 4 channel

• ReadOut Controller: ROC firmware loaded on the SYSCORE FPGA board, (KIP/ZITI)

• DAQ: DABC software (GSI) for free-running systems acquisition

• Monitoring: GO4 framework, (GSI, from the CERN ROOT), used for both online and offline analysis

2. The electronic chain demonstrator

Lab pulser results σ[ps]

chip level 36.94

PCB level 38.94

PCB-PCB level 40.22

ROC and network protocol presented in HK 20.6 and .7 by S. Manz and F. Lemke

The CBM Time of Flight wall electronic readout chain

5/10P.-A. Loizeau – Univ. Heidelberg – HK55.3, DPG 2011, Münster24/03/2011

40 equipped channels: 32 for RPC (16 strips) & 8 for PMTs (4 time reference

scintillators)

3. Proton Test beam at COSY, Jülich: Setup

Front-end

electronics

Readout

controller

Clock generation

and distribution

BEAM

Reference 4

Reference 1

Reference 2

Reference 3

RPC

The CBM Time of Flight wall electronic readout chain

6/10P.-A. Loizeau – Univ. Heidelberg – HK55.3, DPG 2011, Münster24/03/2011

• Channel hit rates between 40Hz and 4kHz, mean rate around 700Hz (correspond to 4Hz/cm², 300 Hz/cm² & and 50 Hz/cm²)

3. Test Beam at COSY

Triggered system used as reference for the performance:

• Data in triggered system taken with the same detector settings

• Performance: presented in previous talk (HK 55.2) by I. Deppner

The CBM Time of Flight wall electronic readout chain

7/10P.-A. Loizeau – Univ. Heidelberg – HK55.3, DPG 2011, Münster24/03/2011

Unpacking using GO4:

• Checking data synchronization

• Ordering data messages (edges)

• Building hits

• Ordering hits

Analysis using ROOT scripts:

• Building events from channel coincidences and external reference signal

• ToT & event structure

• Correction and analysis

• Calibration scripts tested first on triggered data

4. Analysis procedureCleaning, Time Order, Hits: GO4

Event Building

Simplification, ToT

Calibration:

Walk and differential non linearity

root file with raw hits

root file with raw events

root file with reduced events

Calibrated Data

The CBM Time of Flight wall electronic readout chain

8/10P.-A. Loizeau – Univ. Heidelberg – HK55.3, DPG 2011, Münster24/03/2011

• Time difference = difference between the mean time in reference PMTs (4 signals) and the mean time in the RPC strip (2 signals)

• System Resolution for RPC strip 6 after preliminary calibration: 104ps

(with best reference channels and on a fraction of data with stable rate)

• RPC data loss in same data: ~40%

5. Performance: First preliminary results

The CBM Time of Flight wall electronic readout chain

9/10P.-A. Loizeau – Univ. Heidelberg – HK55.3, DPG 2011, Münster24/03/2011

5. Performance: Data loss exampleChannel 37 was lost after ~45 minutes because of a stuck FIFO on digitizer

The CBM Time of Flight wall electronic readout chain

10/10P.-A. Loizeau – Univ. Heidelberg – HK55.3, DPG 2011, Münster24/03/2011

Conclusion

1) Full readout chain put into operation in Nov 2010

2) First free streaming data recorded for our sub-detector, analysis is ongoing

3) Allowed to find some source of data corruption and corresponding recovery methods

4) Still some source of data loss to identify

Outlook1) New tests with updated monitoring tools

2) Optical readout of the ROC (tested in lab, HK 20.6)

3) Test with different RPC demonstrators

4) New version of chain components under development

The CBM Time of Flight wall electronic readout chain

24/03/2011 P.-A. Loizeau – Univ. Heidelberg – HK55.3, DPG 2011, Münster

Thank you for your attention

Many thanks for their help to:

Norbert Herrmann, Ingo Deppner, Jochen Frühauf, Sebastian Manz,

Mircea Ciobanu, Harald Deppe, Holger Flemming, Mladen Kis, Karlsten Koch,

Serguey Linev, Walter F.J. Müller,

Dieter Prasuhn (COSY)

And to all people involved in the development of the readout chain components

CBM-TOF Group Contributing institutions:• Tsinghua Beijing,• NIPNE Bucharest,• GSI Darmstadt,• USTC Hefei,• PI Heidelberg,• KIP Heidelberg,• INR Moscow,• ITEP Moscow,• IHEP Protvino,• FZD Rossendorf,• KU Seoul,• RBI Zagreb.