Frank Geurts Rice University. TOF Timing ◦ HPTDC chip ◦ Calibration for HPTDC Non-Linearity ...

Frank GeurtsRice University

TOF Timing◦ HPTDC chip◦ Calibration for HPTDC Non-Linearity

TOF Performance Monitoring◦ Online Monitoring◦ Prompt Analyses

TOF Offline Analysis◦ Fast Offline QA◦ Overall Layout◦ Matching Algorithm◦ Physics Production Chain and Calibration

TOF Offline resources/organization Summary & Outlook

April 26, 2009Hanghzou Workshop on STAR

TOF 2

Timing based on CERN HPTDC chip Operated in the Very High Resolution Mode:

◦ external clock input 40MHz 11bit coarse timing, 25ns

◦ internal Phased Lock Loop 8x 40MHz 3bit, 3.125ns

◦ internal Delay Locked Loop of 32 cells 5bit, 98ps

◦ internal 4 R-C delay lines 2bit, 24.4ps

21-bit timing information 8 MRPC channels per HPTDC chip

◦ 3 HPTDC chips per TDIG board◦ 8TDIGs per TOF tray


TOF 3

Coarse time(bin width 25ns, 11 bits)

PLL bits(bin width 3.125ns)

DLL bits(bin width 98 ps)

MSB LSB

R-C bits(bin width 24.4 ps)

★) Hig

h P

erfo

rmance

Tim

e to

Dig

ital C

onverte

r

Timing based on Leading Edge (LE) MRPC signal◦ set by a discriminator on the TINO board

Signal-height correction (slewing) based on Time-over-Threshold (ToT)◦ measure the Trailing Edge (TE) of MRPC signal◦ ToT is time difference between LE and TE; proportional

to signal height;◦ slewing correction based on offline calibration

see today’s presentation by Ming Shao

HPTDC has an intrinsic non-linearity◦ due to e.g. process variation◦ requires a per-channel calibration◦ once determined, expect no changes


TOF 4

HPTDCs come with a three sources of non-linearity1. unequal bin widths in RC-tapped delay lines2. unequal bin widths in DLL 3. noise coupling from the logic network (40MHz) into the

sampling clock network (320MHz) Higher level tests show clock feedthrough (#3)

dominates◦ periodicity is 1024 bins (25ns)


TOF 5

Bin number

#entr

ies Differential Non-Linearity (DNL):

• determine statistical bin width using a code density test:

• apply uniform random distribution w.r.t. TDC clock

• compare measured vs. expected #entries

1024 1024

INL correction determined for all TOF HPTDC channels

Full TOF Barrel: 120x192 = 23k TDC channels

1024 bins/channel at 2byte precision

Offline Database: 46Mbyte


TOF 6

RMS 3.993

RMS 3.993

RMS 0.7789

RMS 0.7789

σ = 0.7659 ≈ 18ps σ = 0.7659 ≈ 18ps

INL applied

no INL applied

HPTDC integral non-linearity (INL):

INL(n) = Σi=1..n DNL(i),where DNL(i)= [Nexp – Nmeas(i)] / Nexp






TOF 7

Provides a fast check of the TOF system status◦ occupancy/Dead channels◦ correlation of East/West

upVPD hits◦ time information of TOF hits◦ etc. etc.

Widely used during Run 8/9◦ 7 pages, 20 histograms◦ new version will soon be

deployed includes data-integrity checks


TOF 8

Embedded in the STAR Online Monitoring code

Data integrity/consistency◦ verify TOF consistency of TOF data

headers◦ see http://www.rhip.utexas.edu/~lli/tof/◦ part of this can be moved to Online

Monitoring Dedicated noise runs

◦ dedicated TOF “pedestal” run (pedAsPhys_tof) count #triggers in 5μs trigger-matching

window at a ~3.5kHz STAR trigger rate◦ prompt analysis of Leading and Trailing

Edge noise rates for each MRPC channel◦ see

http://www.rhip.utexas.edu/~tofp/var/rts/


TOF 9

Run #10105009 Tray-19Leading Edge noise






TOF 10

New offline DAQ reader based on RTSReader◦ TOF data format specs v2.4★

◦ implemented Run 8


TOF 11

StBTofHitMakerStBTofHitMaker

DAQ TOF Branch

DAQ TOF Branch

StBTofCollection:• StBTofHeader• StBTofRawHit• StBTofHit

StBTofCollection:• StBTofHeader• StBTofRawHit• StBTofHit

◦ fiber data status and trigger time are stored in StBTofHeader

◦ leading-edge and trailing-edge values are stored in StBTofRawHit

◦ INL-corrected LE and TE values stored in StBTofHit

★) http://www.star.bnl.gov/public/tof/electronics/TOF_Fiber_Data_Format_v2_4.pdf

event-wise hit distributions matched hit distributions channel-by-channel timing distributions

◦ requires fast-offline calibration by experts◦ Vz from upVPD, TOF PID

Implemented in StEventQAMaker During Run 8 and Run 9 (500GeV) QA by TOF

experts MatchMaker will soon be included in Fast Offline


TOF 12

Offline DAQ

Offline DAQ

Fast Offline Reconstruction

Fast Offline Reconstruction

EventQAMakerEventQAMaker

histogramshistograms

QA by shift crew


TOF 13

STAR/TOF DAQ

STAR/TOF DAQ

GSTARgeant hits

GSTARgeant hits geometry

(btofgeo)geometry (btofgeo)

TOF Offline DAQ readerStBTofHitMaker

TOF Offline DAQ readerStBTofHitMaker TOF Simulation MakerTOF Simulation Maker

TOF Mixer Maker

TOF Mixer Maker

StBTofMatchMakerStBTofMatchMaker

StBTofCalibMakerStBTofCalibMaker

StEventStEvent

StB

TofC

olle

ctio

nStB

TofC

olle

ctio

n

StBTofRawHitStBtofHeaderStBTofRawHitStBtofHeader

StBTofHitStBTofHit

StTrackStTrackStBTofPidTraitsStBTofPidTraits

StMuBTofUtilStMuDstMakerStMuBTofUtil

StMuDstMaker

MuDst TOFMuDst TOF

StMcEventStMcEvent

StMcTofHitStMcTofHit

BTofRawHitBTofHit

BTofHeader

BTofRawHitBTofHit

BTofHeader

association

DB TablesStBTofUtilStBTofPool

DB TablesStBTofUtilStBTofPool

btofgeo.g and vpddgeo.g provide various TOF/VPD geometries:◦ btofgeo.g -- btofConfigure

◦ vpddgeo.g -- vpddConfigure


TOF 14

1 Full CTB Run 1

2 Full TOFp --

3 25% TOFp +75% CTB

--

4 TOFp +CTB Run 2

5 TOFp+TOFr+CTB Run 3

6 Full MRPC-TOF Run 9++

7 TOFp+TOFr’+CTB Run 4

8 TOFr5+CTB Run 5

9 - Run 6

10 - Run 7

11 5 TOFr8+CTB Run 8

1-6 pVPD Run 2-5

7 upVPD Run 6++

p+p tof-tpx trigger data◦ ~120k from run #9056082◦ ~45k good matched TPX tracks with TOF hits


TOF 15

Expect to see a similar plot for Run-9 500GeV soon.


TOF 16

StEventStEventStBTofCollectionStBTofCollection

StBTofHitStBTofHit

Track Nodes (global)Track Nodes (global)

StBTofPidTraitsStBTofPidTraits

Projected TOF HitsProjected TOF HitsFired TOF HitsFired TOF Hits

Init Matched TOF Hits

Init Matched TOF Hits

Singly-Tracked Matched Hits Singly-Tracked Matched Hits

Final Matched TOF Hits

Final Matched TOF Hits

Track projection on TOF

Matching of hits within one pad

distance

Associate one TOF hit with

multiple tracksOne track with multiple TOF

hits

•TOF Cell Index•Timing•Projected position•Associated Track

… and remove


TOF 17

StBTofHitMakerStBTofHitMaker

DB TablesStBTofUtilDB TablesStBTofUtil

StBTofCalibMakerStBTofCalibMaker

StBTofMatchMakerStBTofMatchMaker

StMuDstMaker/StMuBTOFUtilStMuDstMaker/StMuBTOFUtil

STBTofNtupleMakerSTBTofNtupleMaker

Trees for Calibration

Active Tables (i.e. relevant to BTOF)


TOF 18

tofConfig General configuration for Barrel TOF

tofTrayConfig Tray Configuration

tofTDIGOnTray Mapping of TDIG boards on trays

tofDaqMap Mapping between TDIG channels and TOF cells or upVPD tubes

tofINLCorr/tofINLSCorr INL Correction table (channel-by-channel)

tofPhaseOffset Phase offsets between THUBs

tofTOffset Calibration table: T0 for each channel

tofTotCorr Calibration table: T-Tot corrections

tofZCorr Calibration table: T-Z corrections

tofGeomAlign Tray alignment parameters

tofStatus TOF status table

MuDST more compact than StEvent◦ allows essential StEvent objects to be rebuild in memory

TOF branches in MuDst are filled by StMuDstMaker::fillBTof

TOF branches in MuDst◦ structure StMuBTofHit

modified from StBTofHit using StMuBTofUtil::fillMuBTofHit ◦ structures StBtofRawHit, SBtTofHeader

direct copy from StBTofCollection

TOF PID traits in StMuTrack◦ StMuTrack::muBTofPidTraits◦ Structure: StMuBTofPidTraits: modified from StBTofPidTraits


TOF 19


TOF 20

Run 9 (500GeV p+p): Fast-offline based production of 3.7M events finished






TOF 21

Online Plot: J.Liu Offline QA: L.Li, M.Wada, X.Zhang, Y.Zhou Calibration: Z.Tang, X.Zhang, J.Liu, X.Zhu, M.Shao

L.Ruan Chain Makers: X.Dong, F.Geurts Geometry: W.Llope, X.Dong Simulation: D.Thein, L.Ruan, F.Geurts Database: X.Dong, F.Geurts VPD: X.Zhang, J.Zhou, X.Zhu, Y.Xu PID: C.Markert, M.Wada, L.Li

Coordinator: F.Geurts◦ many thanks to X.Dong!

Institutes: BNL, LBNL, Rice, Tsinghua, USTC, UT Austin


TOF 22

weekly meetings◦ Wednesday 1h30pm EST◦ switch to EVO-based

widely in use in high-energy community STAR community exists, too get an account (www.caltech.edu/evo)

topical meetings◦ as needed

early connection with PWGs◦ include TOF-based PID◦ efficiency (embedding)


TOF 23

TOF Offline Software is in a good shape◦ Online Monitoring and FastOffline QA well integrated in

STAR framework◦ Migration to a new StEvent model is almost completed

STAR offline software review (Nov.’08) provided useful feedback ahead of Run 9

Decouple prototype software support and maintenance◦ Matching and Calibration procedures/software have

been tested for several years using the TOF prototypes◦ Database tables are well maintained for offline analysis

Run-9: Efficiently handle the significant increase of channels that comes with a Large Area TOF◦ jump from 4 to 75% of the full TOF◦ optimized various aspects of the offline framework

database loading!


TOF 24

Continue Particle Identification method development - integrated with dE/dx

Simulator development Efficiency

◦ Embedding and association Include “start-less” TOF analysis

◦ relevant in low-energy runs where upVPD may not be very efficient

Connect early with STAR PWGs and have TOF PID included in many physics analyses


TOF 25

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Frank Geurts Rice University. TOF Timing ◦ HPTDC chip ◦ Calibration for HPTDC Non-Linearity ...

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