09/12/2009 ALICE TOF General meeting 1

Online Controls

Andrea Alici

INFN and Universtity of Bologna,

Bologna, Italy

ALICE TOF General Meeting

CERN building 29, 9 December 2009

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The Detector Control System (DCS) has to provide:

A full detector description and a direct access to devices (HV and LV power supplies, VME crates, electronics cards, …);

Finite State Machine (FSM) based mechanism to synchronize the state of the detector with the operation of the physics data acquisition system and with LHC state;

Online controls.

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Online controls means:

Continuously monitoring of important parameters as:• environmental parameters (Cavern temperature, pressure and

humidity, magnets current and voltage, …)• services (gas distribution, cooling water circulation, …)• detector operational parameters (HV and LV channels current,

readout status, …)

Archiving of most relevant parameter values (HV and LV channels current, boards temperature, …) to allow a further access to this information. At present 4520 parameters are being archived.

Alarm handling which provide a way to signal in real time any abnormal behavior with defined manual or automatic actions to be taken in order to recover it. More than 6480 alarms have been defined.

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Services:

• Gas Distribution system

• Cooling system

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Gas Distribution system

TOF total gas flow 40 l/h per SM

Ingoing and outgoing fluxes for each half of SM are monitored

At present the SMs are fluxed with an 93% C2H2F4 and 7% SF6 gas mixture

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Water temperature at the beginning of the cooling line

Water temperature at the end of the cooling line

Water Cooling system

Cooling water fluxes for Read-out and Front-end electronics

TOF startup on 25 September 2009

Day and time

14°C

15°C

16°C

17°C

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TOF Operational parameters:

• TOF temperature

• Front-end cards online monitor

• Full TOF dark current

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TOF Temperature

The temperature of the TOF is continuously monitored by means of 576 + 8064 = 8640 temperature sensors.

Average crate internal temperature ≈ 32°C

Average temperature in the SM electronic volume ≈ 17°C

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TOF Temperature

TOF turned off

The increase of L3 temperature due by the TOF is of the order of 0.6°C in a good agreement with the ALICE request.

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TOF Temperature

SuperModules

Side C

Side A

Electronic cards off because of power supply failures

A non uniformity has still to be completely understood.

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Front-end cards online monitor

The FEAC cards distribute the power supply and the threshold level to the FEAs and get back the OR signal of each couple of deasy-chained FEAs.

The main Front-end card parameters are read back by the Local Trigger Module (LTM). There are 1 LTM and 8 FEA Controller cards for each quarter of SM.

FEAController

x8

LTM

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Front-end cards online monitor

macro-pad (48 pads) single rate ≈ 33.6 Hz 0.08 Hz/cm2

FEAController

x8

LTM

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HV channels OFF, average current 1.7uA

Average current drawn by full TOF @ 13 kV is less than 1uA (1568 MRPCs in total less then 1nA per MRPC).

Full TOF Dark Current

HV channels @ 1kV (safe condition with unstable beams)

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Conclusions:

All the environmental parameters, services and detector operational parameters are continuously monitored.

Tools have been developed to signal in real time any dangerous or abnormal behavior and to automatically recover it.

From an hardware point of view the TOF detector looks working fine.

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RESERVE

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Water temperature at the beginning of the line

Water temperature at the end of the line 355 (l/min) * 1.5 kQ ≈ 2,23 MJ/min

47kW/sec ≈ 2.82 MJ/min

Water Cooling system

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pp collisions