Performance analysis of the Nb−Ti conductor qualification samples for the ITER project

Breschi, Marco; Carati, Daniela; Bessette, D.; Devred, A.; Romano, G.; Vostner, A.; Zhou, Chao

doi:10.1088/0953-2048/28/11/115001

Cited by 13 publications

(10 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This amplitude of the applied sinusoidal single pulse is increased stepwise progressively until a quench occurs. The MQE assessment procedure is detailed in [18]. The energy deposited is determined considering the helium temperature difference, measured between upstream and downstream sensors and by using the mass-flow rate and the helium specific heat [19].…”

Section: Mqe Test and Analysismentioning

confidence: 99%

Analysis of ITER NbTi and Nb₃Sn CICCs experimental minimum quench energy with JackPot, MCM and THEA models

Bagni

Duchateau²,

Breschi

et al. 2017

Supercond. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

Cable-in-conduit conductors (CICCs) for ITER magnets are subjected to fast changing magnetic fields during the plasma-operating scenario. In order to anticipate the limitations of conductors under the foreseen operating conditions, it is essential to have a better understanding of the stability margin of magnets. In the last decade ITER has launched a campaign for characterization of several types of NbTi and Nb3Sn CICCs comprising quench tests with a singular sine wave fast magnetic field pulse and relatively small amplitude. The stability tests, performed in the SULTAN facility, were reproduced and analyzed using two codes: JackPot-AC/DC, an electromagnetic-thermal numerical model for CICCs, developed at the University of Twente (van Lanen and Nijhuis 2010 Cryogenics 50 139–148) and multi-constant-model (MCM) (Turck and Zani 2010 Cryogenics 50 443–9), an analytical model for CICCs coupling losses. The outputs of both codes were combined with thermal, hydraulic and electric analysis of superconducting cables to predict the minimum quench energy (MQE) (Bottura et al 2000 Cryogenics 40 617–26). The experimental AC loss results were used to calibrate the JackPot and MCM models and to reproduce the energy deposited in the cable during an MQE test. The agreement between experiments and models confirm a good comprehension of the various CICCs thermal and electromagnetic phenomena. The differences between the analytical MCM and numerical JackPot approaches are discussed. The results provide a good basis for further investigation of CICC stability under plasma scenario conditions using magnetic field pulses with lower ramp rate and higher amplitude.

show abstract

Section: Mqe Test and Analysismentioning

confidence: 99%

Analysis of ITER NbTi and Nb₃Sn CICCs experimental minimum quench energy with JackPot, MCM and THEA models

Bagni

Duchateau²,

Breschi

et al. 2017

Supercond. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The T cs is evaluated by means of the electrical method based on the evaluation of the voltage drop measured along the HFZ [16]. A detailed description of the analysis procedures for the SULTAN DC and AC measurements can be found in [17,18].…”

Section: Measurementsmentioning

confidence: 99%

DTT toroidal field conductor samples test in Sultan: DC and AC characterization

Fiamozzi Zignani,

De Marzi,

Scarantino

et al. 2024

Supercond. Sci. Technol.

View full text Add to dashboard Cite

The superconducting magnet system of the Divertor Tokamak Test (DTT) facility, composed of 18 Toroidal Field (TF) coils, 6 Poloidal Field (PF) coils and a Central Solenoid (CS), has been designed and many procurements have been launched. Some manufacturing aspects and some conductor features require characterization under relevant close-to-operative conditions. To confirm the design choices in all details, cryogenic tests in qualified facilities have been foreseen. In this work, the results of the TF samples characterization at the SULTAN facility at the Swiss Plasma Centre (SPC, EPFL) are presented. The 3 weeks test campaign started on July the 8th, 2022. The DTT TF SULTAN sample was made of two Nb3Sn Cable-in-Conduit conductor “legs”, namely “TF-A” and “TF-B”, made with wires produced by Kiswire Advanced Technology (KAT), differing for the cabling twist pitch sequence only, and designed to work in DTT at 42.5 kA at 11.9 T peak field.The extensive characterization comprised 3000 Electro-Magnetic (EM) cycles and two Warm-Up-Cool-Down (WUCD) steps, and in detail it included: AC measurements on the virgin conductors, on cyclic loaded conductors and after WUCDs; DC tests at 10.85 T / 42.5 kA with intermediate electro-magnetic (EM) cycles at 10.85 T / 45 kA before and after WUCDs; DC tests using partial Lorentz force loads, and Minimum Quench Energy (MQE) tests at 9 T / 42.5 kA after cycles and WUCDs. The results of the DC measurements analysis verified the design, in terms of current sharing temperature (Tcs) and critical current (Ic), as both samples are over the minimum acceptance values. In particular, the “TF-A” sample, characterized by a so-called “long twist pitch” cabling sequence, showed higher performance without any degradation with loading and WUCD cycles, whereas sample “TF-B” presented an initial Tcs reduction that afterwards substantially remained unchanged. In terms of strain acting at the Nb3Sn filaments level, this result can be described by a lower effective strain in the “TF-A” sample. AC losses were measured with a calorimetric method as a function of frequency for each series of AC sinusoidal pulsing measurements, and the characteristic coupling time constants were determined.

show abstract

“…where B dc is the background magnetic field, I op is the operation current, µ 0 the magnetic permeability in vacuum, R is the conductor bundle radius and a is the distance between the centers of both legs [66].…”

Section: Sultan Test Proceduresmentioning

confidence: 99%

“…Finally the cable is inserted in a stainless steel 316L circular-hole-in-square jacket, see Figure 3.1 for cable and strand cross sections. The main parameters of the CICC are listed in Table 3.1 [66], [78].…”

Section: Pfeu2: Conductor Layout and Parametersmentioning

confidence: 99%

“…The amplitude of the applied sinusoidal single pulse is progressively increased stepwise until a quench occurs. The MQE assessment procedure is detailed in [66]. The energy deposited is determined by the temperature difference measured between the temperature sensors upstream and downstream the High Field Zone (HFZ), see section 2.2.1, based on the mass-flow rate and the helium specific heat [80], see eq.…”

Section: Stability Testsmentioning

confidence: 99%

See 1 more Smart Citation

Modeling electro-magnetic and thermal Stability of Cable-in-Conduit Superconductors for Fusion Magnets

Bagni

View full text Add to dashboard Cite

The views and the opinions expressed herein do not necessarily reflect those of the ITER Organization as well as EUROFusion. vi vii per mio padre to my father viii xix 5.4. JackPot Plasma Scenario short sample simulation _____________ 5.4.1. Magneto-resistance and Lorentz' force effect ___________________ 5.4.2. Simulation results ________________________________________ 5.5. Temperature evolution in a layer of CSU2 module ____________ 5.5.1. JaskPot-THEA results ______________________________________ 5.6. Conclusion ____________________________________________

show abstract

Performance analysis of the Nb−Ti conductor qualification samples for the ITER project

Cited by 13 publications

References 32 publications

Analysis of ITER NbTi and Nb₃Sn CICCs experimental minimum quench energy with JackPot, MCM and THEA models

Analysis of ITER NbTi and Nb₃Sn CICCs experimental minimum quench energy with JackPot, MCM and THEA models

DTT toroidal field conductor samples test in Sultan: DC and AC characterization

Modeling electro-magnetic and thermal Stability of Cable-in-Conduit Superconductors for Fusion Magnets

Contact Info

Product

Resources

About

Performance analysis of the Nb−Ti conductor qualification samples for the ITER project

Cited by 13 publications

References 32 publications

Analysis of ITER NbTi and Nb3Sn CICCs experimental minimum quench energy with JackPot, MCM and THEA models

Analysis of ITER NbTi and Nb3Sn CICCs experimental minimum quench energy with JackPot, MCM and THEA models

DTT toroidal field conductor samples test in Sultan: DC and AC characterization

Modeling electro-magnetic and thermal Stability of Cable-in-Conduit Superconductors for Fusion Magnets

Contact Info

Product

Resources

About

Analysis of ITER NbTi and Nb₃Sn CICCs experimental minimum quench energy with JackPot, MCM and THEA models

Analysis of ITER NbTi and Nb₃Sn CICCs experimental minimum quench energy with JackPot, MCM and THEA models