SPD Calibration Requirements

Par #

Parameter

Data format/size per channel

Data size (Total) Bytes

Update freq

Source

Confirmed

Run type / Trigger type

# of required events/sampling rate

Processing level: sub-event or event

Results: FEE/Archive

Accessible by offline

Calib. Procedure in AliRoot

use case #

in OCDB

reference

1

List of dead/noisy pixels and chips

4 Bytes

1.00E+07

2.00E+07

Whenever there is a ~30 minutes dead time (fill,…) the values are compared to previous ones and updated if changes – Typical: weekly

DCS/DAQ

Physics and Calibration / CTP and DCS

for physics          dead: 100 M @p-p and 100 K @Pb-Pb   noisy: 100 K

sub-event

OCDB + Noisy in DCS-CDB

yes

yes

1-3

2

Threshold

4.00E+08

DCS/DAQ

Calibration / DCS

sub-event

DCS-CDB

no

yes

1-3

3

Noise level

4.00E+08

DCS/DAQ

Calibration / DCS

sub-event

DCS-CDB

no

yes

1-3

4

Uniformity of response

2.00E+07

DCS/DAQ

Calibration / DCS

sub-event

DCS-CDB

no

yes

1-3

5

FO uniformity

2.00E+07

DCS/DAQ

Calibration / DCS

sub-event

DCS-CDB

no

yes

1-3

6

Delays

4.00E+08

DCS/DAQ

Calibration / CTP

sub-event

DCS-CDB

no

yes

1-3

7

Parameters from general DAC scan

4.00E+08

DCS/DAQ

Calibration / DCS

sub-event

no

yes

1-3

1.00E+07

1.66E+09

DCS access - offline has access only to DCS archive DB, curently no access to configuration DB

DAQ - offline has access to raw data and DAQ logbook, but no acccess to LDC or GDC directly

OCDB - Calibration parameters are stored in the Offline Calibration DB. The data used to calculate these parameters, the reference data, can also be optionally archived for later access from offline.