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Enhanced DQHDS functionality

Status for 2011

Increase Magnet diagnostic capabilities

Our proposals

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Status for 2011

Based on 2010 experience the following improvements will be implemented for the 2011 run– Replacement of main switches as many as feasible during Xmas break– Additional software interlock creating a warning message followed by a

slow abort after a certain delay when we lose:• One DQHDS of an IPQ, IPD, IT or MQ magnet • Two DQHDS of a MB magnet

– Firmware upgrade for the local protection data acquisition boards (DQAMC) installed in hot zones (P3, P7 ,L2 ,R8 )

• Only 3 out of 4 dipole DQHDS required for QPS_OK• Secondary Pm trigger on DQHDS voltage – discharge curves as

well recorded in case only symmetric quench detection is triggering DQHDS (useful during commissioning / no current in the circuit)

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Increase Magnet diagnostic capabilities

– Present system monitors quench heater voltage – sufficient for healthy heater circuits

– Some dipole magnets are equipped with quench heaters which may show problems during LHC exploitation

Magnet experts are asking us if we can increase diagnostic capabilities for qualification and possible fault detection of the LHC main dipole quench heater circuits – Their wish list:

• Perform discharge tests with lower energy• Monitor discharge current • Check electrical continuity of quench heater after discharge• Check quench heater sanity (if possible)• Check for eventual earth faults

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Our proposals

Magnet expert wish list to be very carefully looked with respect to additional risks and feasibility:– Perform discharge tests with lower energy

• Feasible with existing hardware during DQHDS recharge (switch-on campaign after a shutdown) by using a new dedicated software tool to be tested for IPQ already this shutdown

– Monitor discharge current• Feasible with additional hardware (shunt resistor or current sensor)

in combination with new version of DQAMC type data acquisition system (additional analog inputs including connections plus higher sampling rates required)

• Additional risks due to modification of the 6076 discharge circuits• Not excluded but not for free either

– Check electrical continuity of quench heater after discharge• Fault normally revealed by PM files• A software trigger of a low voltage discharge after each Quench (full

power discharge) can be easily implemented.

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Our proposals (continued)

– Check quench heater sanity (testing for partly broken heaters)• Discussions with several experts led to the conclusion that a

possible solution will require a sophisticated data acquisition system allowing to record HF signals during test discharges

• Very expansive solution for 6076 devices, which may require in addition a new physical fieldbus layer for data transmission

• Development of a radiation tolerant version of such a device not straightforward (if feasible at all)

• Proposal is to use mobile devices and test to be integrated into ELQA procedures

– Heaters Earth faults check• We think the best way, is to make an insulation test with a mobile

tester (eg: during the ELQA MIC test)

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