DR, 19. 5. 2009 1

SC strand and cable measurement instrumentation

Mechanical testing of superconductorslab. 103

Low-temperature electrical testing of superconductorslab. 163

Internal review of superconductors and magnet laboratories, CERN May 19, 20, 2009

DR, 19. 5. 2009 2

Instrumentation of lab. 103(Mechanical testing)

• PC controlled(-able) instruments– Cable Measurement Engine (2x+3x):

QBasic, DAS-8PGA card.

– Cable Inspection System (2x+5x)Pattern recognition video system for Rutherford-type cables.

– EMPA mandrel movement optical monitoring system.

– Cable thermal contraction measurement bench.

– Coulometer (2x).

• Developed for and very extensively used during the LHC cable production

DR, 19. 5. 2009 3

Test stations lab. 163(Low-temperature electrical testing)

As built for LHC

• 4x IC- strand NbTi

• 1x M(H)-strand

• 2x rrr/RC

• 1x Fresca

• ---------------------------

• 1x Com. with Cryo

Present

• 2x IC- strand NbTi

• 1x IC- strand Nb3Sn

• 1x Heat transfer

• 1x M(H)-strand

• 1x rrr/RC

• 1x Fresca

• ---------------------------

• 1x Com. with Cryo

Next: 1 of alternatives

• 2x IC- strand ITER

• 2x IC- strand Nb3Sn

• 1x M(H)-cable/IC-HTSc

• 1x M(H)/loss-strand

• 1x rrr/RC

• 1x Fresca1x Heat transfer

• ---------------------------

• Com. with Cryo

7 + 1 pits available in 163

DR, 19. 5. 2009 4

Testing electronics

sunmms

K2001

SC magnet current supply

T regulationPS

T-gaugeI-supply

Dispatch box

K2000

K182

IEEE-488

QP detection

QP securitymatrix

Function generator

Charger and current amplifier

2x Accu

1 kA test current switch1.5 kA DCCT

Up to 27 m long 20 mA RS 232 transmitting IEEE-488 information

K7001

NbTi Ic-strand example

DR, 19. 5. 2009 5

Control computer

• 10x somewhat obsolete SunBlade or SunUltra– Problems very rare, not supported at CERN anymore – replacement.– Links: HD cross mount, server regime, afs calls.

• Rather unreliable coax Ethernet– Problems not rare, also for Cryo remote controls.– Under upgrade since months.– Ethernet as noisy as mains – could be isolated, WiFi?

• LabView 5.1 through 7.1– TB updated but not yet a problem in real life.

• Protected mains installed for Controls– Their use somewhat random. Protected mains for test stations? Local UPS?

DR, 19. 5. 2009 6

Control bus

• IEEE-488 bus– 6x RS 232 20 mA loop terminated by an RS 232-to-IEEE-488 convertor serving typically 7

parallel working instruments in each station.

• Difficult management of READs and WRITEs for the control program in order to avoid blocking of the bus.

• We learned how to work in this condition but higher performance IEEE-488 bus would make operation more fluent.

– Nb3Sn IC-strand, HT, and FRESCA on direct IEEE-488.

DR, 19. 5. 2009 7

Instruments conducting the test

• Mixture of: – Current supplies: 1 mA to 32 kA– V-meters: nV, mV, and mV ranges– Switches: nV to kA– DI/Os: 5 V, 24 V– Automates PLC: M(H), Cryo communications– Quench security

• Most of them fulfill their function and do not have TB replaced yet– From time to time some burn and need replacement, typically during summer – air

temperature 35 C.– All stations use the same instruments: Sufficient internal redundancy in case of failure. CERN

Electronics Pool offers some of them. All instruments still manufactured.Failure of any electrical instrument, with the exception of the multi-kA power supplies for the Nb3Sn IC-strand, M(H)-cable and FRESCA should not result in more than few-days stoppage.

• Sensors & Heaters– Available: Small stock of GRT, Cernox, CLTS, and Pt100 sensors, MINCO foil heaters.– Low stock of LHe level meters.– Stock TB revised.

DR, 19. 5. 2009 8

PXI upgrade option

sunmms

K2001

SC magnet current supply

T regulationPS

T-gaugeI-supply

Dispatch box

K2000

K182

IEEE-488

QP detection

QP securitymatrix

Function generator

Charger and current amplifier

2x Accu

1 kA test current switch1.5 kA DCCT

Up to 27 m long 20 mA RS 232 transmitting IEEE-488 information

K7001

PXI

NbTi Ic-strand example

Cost:About 6000÷15 000 EUR/station & partial re-programming of the LabView code & partial re-cabling.

Essential gain: Smoother communication, possible replacement of 2.5 instruments.

DR, 19. 5. 2009 9

Two current supplies to look at

• 5 pieces of 1 kA battery powered current supplies for IC-strand test (TE/MSC)– Need maintenance: battery replacement, revision of charger electronics

and of cooler, adjustment/replacement of water interlock.

• Power supply for M(H) test– ISR original material.

– Need for bipolarity, better control of current, reliability, smaller volume.

– Would better be replaced by a new one.

DR, 19. 5. 2009 10

Calibration

• Multimeters– The 21 DMMs and 15 nV-meters Keihley, which are the core of the

DAQ should be regularly calibrated.

– Last systematic calibration done in 2000.

• Temperature sensors– LakeShore Germanium and Cernox sensors used. Last calibration

campaign done in 2002 and 2004 – actual status TB verified.

• Similar concerns the 1.5 kA DCCTs

DR, 19. 5. 2009 11

EM noise & Co.

• TBD: De-coupling from mains and from Ethernet for sensitive measurements: – Double conversion UPS + separation transformer + WiFi(?).

• TBD: Installation of filters on cranes and verification of EM emission useful

• TBD: Protection of sensitive instruments against draughts in winter, and from overheat in summer– Temperature driven auto-calibrations TB added.

DR, 19. 5. 2009 12

Cabling and others

• Signal and control cabling– needs revision - connectors in particular (10 years in operation).

• Ventilation inside instrument racks - cleaning/revision

• Maintenance/upgrade of cooling water circuits– More de-mineralized water needed?– Utility water circuit TB purged, interlocks changed/adjusted.– Water-cooled cables TB revised.

• Mechanical tooling needs revision small repairs/re-placements/cleaning

DR, 19. 5. 2009 13

FRESCA particular

• SC current transformer for FRESCA– Transformer and its control electronics to be re-assembled and

put into operation, some development of the electronics expected.

• Warm instrumentation cabling– Diverse provisional cabling TB replaced by a definitive one.

• Sample holders– Diverse sample holders TB inventoried and documented.

DR, 19. 5. 2009 14

Control programs (CP)• The LabView based control software proved rather reliable and efficient during the

extensive 5-year testing of superconductors for the LHC, and afterwards.

• CPs sontrol all (or almost all) test parameters and can run reasonably unattended over hours to complete series of tests: All use programmable sequencers – agendas.

• Built-in LHC-tailored quality control– IC-strand verifies instrument configuration.– Either have on-line automatic analysis of the test result, or they do not need it.– Many use reference sample as aid for on-line validation.– They all rely on final off-line acceptance of data by educated follower.

• Interactions of the CP– Interaction with Cryogenics– Interaction with Database– Calls to afs– Mail, phone alerts

DR, 19. 5. 2009 15

Upgrade of the CPs desirable

• Diverse upgrades desirable for CPs:

– LHC-type control features TB revised/removed/extended: Sample ID control, assumptions about sample parameters, assumptions about test procedure.

– Bi-directional-relation with the LHC database TB updated.

– Change of all READs and WRITEs and bus sequencing in case of RS232 loop removal.

– Periodic auto-calibration should be introduced in CPs.

– New requirements on test algorithm for all tests: IC-strand, M(H), rrr, RC.

– Algorithm extended for non-standard tests: Rc used for rrr of BB, rrr used for r(T) of SnAg.

DR, 19. 5. 2009 16

Sources of Control programs

TE/MPE, TE/MSC (LHC/MMS):

• IC- strand NbTi

• IC- strand Nb3Sn

• Daq & data evaluation in M(H)• rrr

• RC test

• RC follow-up

• Data evaluation for Fresca• Heat transfer• Communication with Cryogenics• Data storage, retrieval, and post-

processing• CME modifications• Cable thermal contraction

EN/ICE

• Data acquisition in M(H)

• Data acquisition for Fresca

Outside CERN:

• Cable Measurement Engine

• Cable Inspection System

• Mandrel Monitoring EMPA

DR, 19. 5. 2009 17

Database from the user’s point of view• LHC production period

– Highly efficient and specialized Database at the center of the LHC-centered activity of the section:Data storage, contract follow-up, test sample flow, test reference data, and test data approval and tracability.

– Limited diversity of tests and samples × very high number of tests. Database inter-linked with testing programs. Concise paper logging - all information available from the DB.

• Current status and future– Unlike the LHC production: Diversified samples, Nb3Sn dominant.

• We urgently need ‘new’ database– The Database TB re-established in all its roles according to changed activities of the

Section.– Actual state of the Database and its links to other SW TB inventoried.– Data approval procedures, automatic data tracability and test logging TB re-established/enhanced.– To offer fast read and load from daq & post-processing SW.– Well and simply organized flat files in right place are valuable complement ideal for creativity and raw data

manipulation. – The database is to be accessed primarily from inside CERN and by interfaces written in different languages.

External-to-CERN access must not impose restrictions on the in-house function of the database. – The users are TRAINED EXPERTS, who do their best to do good job – DB kind to users.