MQXF Series: Strand I c - PowerPoint Presentation

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MQXF Series:Strand Ic and RRR Measurements

B. Bordini

Internal MeetingCERN – 27th June 2018

Measurements from B-OST per billet1

Ic and 1 RRR of round samples for just the

point, tail and first break/cut unless any of the point, break, or tail samples have a le (15 T) <350A or a RRR (round) < 200, then all break/cut samples will be measured for that billet.

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I

c and 1 RRR of a 15% rolled sample from the tail of the billet

MQXF Series: Strand Ic and RRR Measurements – B. Bordini

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CERN MeasurementsThree type of samples:

Verification measurements to accept material Cable Qualification measurements to qualify the cabling process

Witness samples to qualify the coil heat treatment and to calculate the short sample limit of the magnet MQXF Series: Strand Ic and RRR Measurements – B. Bordini

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CERN Measurements VerificationMQXF Series: Strand Ic and RRR Measurements – B. Bordini

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1

I

c

and 1 RRR of round

samples for each spoolTo approve

the materialTo estimate the

variation of the critical current of the wires within a coilTo have

reference values for estimating the quality of the coil heat-treatment 1 Ic and 1 RRR of a

15% rolled sample per billetTo approve the materialFor the first contract of the series F663/Am3 (370 km – 10 coils) received 44 billets with an average of 3.16 spools per billet

Relatively low number of Ic measurements 4.16 per billet

CERN Measurements Cable QualificationMQXF Series: Strand Ic and RRR Measurements – B. Bordini

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A cable for the MQXF series uses 33.6 km of wire and it is generally manufactured by using 4 billets

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I

c and 1 RRR extracted strand sample (and their respective adjacent round wire) per each billet used in the cable

To qualify the cabling process

To estimate the degradation due to cabling in order to properly evaluate the critical current of the coil

About 8 Ic (and RRR) samples per coil

50 coils and 55 cables are planned for HL-LHC (CERN)

In order to qualify the heat treatment used to react the coil, 6 Ic

and 6 RRR ‘witness’ wire samples are reacted together with the coil.The I

c samples are 3 extracted strands (from the cable used in the coil) and their respective 3 adjacent round wires. These samples are coming from three different wire billets.The RRR samples are taken adjacently to the Ic samples.

MQXF Series: Strand Ic and RRR Measurements – B. Bordini

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CERN Measurements

Witness Samples

Cost of measurements is of the order of 10% of strand

Even less (5%) if we consider the full coilBecause of the relevance of the information provided by the strand measurements and their relatively low cost, the number of measurements that CERN performs seems completely justified

MQXF Series: Strand Ic and RRR Measurements – B. Bordini

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CERN

I

c

Measurements per Coil

Verification Measurements (carried out at FSU): 50% of the measurements performed by OST (4 per billet) with the option of reducing them later on

To accept material No Ic measurements for the cable qualification (just RRR)

Six witness samples, 4 extracted samples (3 measured) and 2 virgin sample (1 measured)Extracted samples to estimate the coil short sample limitVirgin samples to qualify the heat treatment

MQXF Series: Strand Ic and RRR Measurements – B. Bordini

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AUP

I

c

Measurements