1 Tests to Determine Lengths during Reaction of LQ cable R. Bossert, F. Nobrega, N. Andreev, G. Ambrosio, I. Novitski

2 Ref: D.R. Dietderich, J.R. Litty, and R.M. Scanlan, Dimensional changes of Nb3Sn, Nb3Al and Bi2Sr2CaCu2O8 conductors during heat treatment and their implication for coil design, ACE(Materials) V44B, p

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6 Test pieces of cable will be 1 meter long, insulated pieces of RRP 54/61 LQ or TQ cable. They will be placed into channels of a fixture configured as shown in cross section below. The fixture is made of 1020 steel. Space provided will constrain the cable in width but be ample to allow the cable to grow in azimuth with reaction and slide freely. Test Setup 1020 steel is used for the fixture because it has a CTE smaller than that of the cable. Therefore, when the cable is expanding longitudinally, it will move faster than the fixture, and be able to maintain contact with the free metal block. When the cable is contracting, it will contract faster than the fixture, ensuring that the free metal block (also 1020 steel) does not slide with respect to the fixture. When the final measurements to the metal block are taken after cool-down, the movement of the block due to the CTE of 1020 steel will need to be subtracted from the total amount measured. 3 samples will be used in each test, allowing us to assess the consistency between tests.

7 For Discussion Accuracy of underlying assumptions. General comments on test. Profile of heat treatment of samples. To verify whether or not 150C is the correct temperature at which stress relaxation begins, the temperature could be reduced to 22C after the initial increase to 150C, the free block measured, then compared to the final measurement after the first test. Sample size (3 or more?). Add an already-reacted cable to one channel? Choice of filler material to be used during test? Pre-heat treatment of 1020 steel test structure to eliminate stress relaxation during test. Further tests with “compressed” cable? Other?

8 (a) Fractional change in length of an ITER conductor produced by IGC-AS. This 19 sub- element wire with 50 % Cu (b) Fractional change in length of a bronze processed conductor produced by Hitachi. (a) (b)