LKr Calorimeter Control and monitoring R. Fantechi 19/02/2010 R. Fantechi

The basic elements in NA48 CPD Fastbus crates (Readout) Miscellaneous crates not controlled by Caenet Transceiver power supplies Preamplifier power supplies Crate temperatures Monitoring of the ventilation equipment –Temperature and status bits Thermal switches in the racks High voltage system R. Fantechi Green = for NA62

Switching on/off – The principle Anything which is not CAEN crate –Fastbus, transceiver power supplies, preamplifier power supplies –Use two independent lines One for on, one for off Send a pulse (1 sec, could be less) Specific hardware copied from Fastbus crate schematics –Safe mechanism Crates don’t change state if the control is disconnected –Manual on/off in parallel –Optoinsulated control –The controlled object gives also a status bit Read via an optocoupled input register –To be kept in NA62 for transceiver and preamplifier power supplies R. Fantechi

Preamplifier - 1 What are they? –Electronic circuits running in the liquid krypton –Need power supplies (+12V, -3.5V) + one control voltage (+6V) Implementation –4 main power supplies, giving two positive and equal voltages and one negative –Distribution cabling to the 16 boxes on top of the calorimeter –Inside the boxes, there are regulator boards to reduce the voltage to the needed one, connected directly to the connectors on the calorimeter flanges –Each board drives a small fraction of the calorimeter R. Fantechi

Preamplifier - 2 Control –Switch on/off of the 4 main power supplies –Read status bits Monitoring –4 set of analog values from the 4 main power supplies (24 channels) For each one: 2 positive voltages, 1 negative voltage and the 3 relative currents All the measurement are voltages, with suitable conversion factors –64 sets of voltages for the 64 columns of the calorimeter Each column: (one +12V, one 3.5V, one +6V) * 2 (top and bottom) A total of 384 analog channels –React if the voltage/current read is different from the nominal within a predefined delta R. Fantechi

Transceiver - 1 What are they? –Electronic circuits located just outside the LKr cryostat –Functions: shaping and differential drive for cables –Need power supplies (+6V, -6V) Implementation –28 main power supplies, giving one +6V and one – 6V –Switch on/off box located nearby Manual switch possible 220V Solid state relays with the usual switch on/off logic R. Fantechi

Transceiver - 2 Control –Switch on/off of the 28 main power supplies –Additional software interlock to inhibit switch on if the status of the ventilation is not ok Monitoring –28 sets of analog values from the power supplies The 2 voltages The 2 currents 2 temperature channels, implemented with an IC which needs a +5V power supply and provides a voltage proportional to the temperature A total of 168 analog channels –React if the voltage/current/temperature read is different from the nominal within a predefined delta R. Fantechi

Ventilation and thermal switches Ventilation –Set of analog values (temperatures) and status bits coming from various ventilation equipment –In the old system, all were displayed in a single page –Alarm to be set if bad status or temperature out of range Thermal switches –24 thermal switches on top of 24 racks Set to switch at 40 degrees Cabled to optoinsulated input registers There are also installed 24 NTCs to measure the temperature: they are cabled, I think, but never used –Alarm sent if there is a change of state of the switch –Could be easy, with an ELMB, to read also NTCs, if needed R. Fantechi

High voltage Start discussion some time ago –Custom made system –It has the particularity to have floating ADCs on the HV line –NA62 could reuse a reduced set of modules, implying a simpler programming –There is nothing ready to handle this –Even a check with CAEN failed (possible use of the OPC server for their VME HV modules) –It seems reasonable to have an “hybrid system” VME modules read by a PC with simple software Pubblication of data to PVSS via DIM Main power supply will be CAEN Easy implementation of in-burst current measurement R. Fantechi