Il’in A.A., Leading Specialist;
Kovalev I.A., Cand. Sc. (Engineering), Head of Laboratory;
Kruglov S.L., Dr. Sc. (Engineering), Leading Research Scientist;
Polyakov A.V., Leading Specialist;
Shutova D.I., Cand. Sc. (Physics and Mathematics), Research Scientist;
Shcherbakov V.I., Senior Specialist;
National Research Center «Kurchatov Institute»
Dinamic modes of HTS based current-carrying elements
Second generation (2G) high temperature superconductors (HTS) are used in AC superconducting cables, current leads for charged particle accelerators, inductive energy storage systems, windings of motors and generators, etc.
High-current superconducting devices require the development of multi-tape current-carrying elements (CCE) on the basis of HTS. Recently HTS REBCO stacks, soft-soldered along the entire length for thermal and mechanical stability, have become widespread. The study of the performance of such CCEs under dynamic modes and the determination of their limit operating parameters is an important practical task.
The authors experimentally investigated specimens of HTS conductors made of up to 5 REBCO tapes produced by SuperPower and SuperOx in liquid nitrogen at extremely high ramp rates. A new specimen charging technique was developed. The acceptable current and magnetic field ramp rates were determined. A high thermal stability for REBCO conductors in liquid nitrogen was experimentally confirmed at ramp rates up to 320 kA/s. The experimental results are compared with the operational dynamic mode of HTS current leads for the Russian NICA accelerator complex.
AC superconducting cables; current-carrying elements; superconductors; second generation high temperature superconductors; high temperature superconducting tapes; REBCO tapes.
Kryuchkov A.A., Cand. Sc. (Chemistry), Leading Research Scientist, OJSC VNIIKP;
Stepanova T.A., Research Scientist, OJSC VNIIKP
Application of chromatographic methods for the determination of the activation energy of thermal aging of cable PVC compounds
The paper describes the determination of the apparent activation energy of thermal aging (W) of PVC compounds containing a mixture of dioctyl phthalate and diisononyl phthalate as plasticizers using the liquid and gas chromatography methods. The data obtained by these methods agree with each other, as well as with the results of the long-term thermal aging of similar PVC compounds and with the results of the tests using the thermogravimetric analysis method. The authors propose to use the generalized data to verify the accuracy of the results of determination of W PVC compounds.
PVC compound; activation energy; liquid chromatography; inverse gas chromatography of polymers; thermogravimetric analysis.