Analysis of the quench propagation along Nb3Sn Rutherford cables with the THELMA code. Part I: Geometric and thermal models

Abstract

a b s t r a c tThe paper describes the new lumped thermal model recently implemented in THELMA code for the coupled electromagnetic-thermal analysis of superconducting cables. A new geometrical model is also presented, which describes the Rutherford cables used for the accelerator magnets. A first validation of these models has been given by the analysis of the quench longitudinal propagation velocity in the Nb 3 Sn prototype coil SMC3, built and tested in the frame of the EUCARD project for the development of high field magnets for LHC machine. This paper shows in detail the models, while their application to the quench propagation analysis is presented in a companion paper.

Effect of Strand Damage in Nb3Sn Rutherford Cables on the Quench Propagation in Accelerator Magnets

“…Several models have been used to study the quench behavior of Rutherford-type cable structures in the past. Notably, the CUDI model has been used to study their thermal stability [7,8,9] and the THELMA model was used to study quench propagation [10,11].…”

Analysis of the quench propagation along Nb3Sn Rutherford cables with the THELMA code. Part II: Model predictions and comparison with experimental results

“…The strand Cu resistivity is supposed to depend on magnetic field and temperature according to the NIST model [14], with a RRR = 75. The adjacent and crossover contact electrical resistances used as a starting point to compute the THELMA EM contact resistances were R a ¼ 9:4 lX and R c ¼ 1 mX [22], which correspond to the THELMA distributed and spot contact resistances R d ¼ 10:4 nX m and R s ¼ 0:5 mX, determined as described in detail in [6].…”

“…In the paper the relevant experimental aspects and results are described, while the details of the geometrical and thermal models formulation are presented in the companion paper [6].…”