Predictive Analysis of the ITER Poloidal Field Conductor Insert (PFCI) Test Program

Zanino, Roberto; Astrov, M.; Bagnasco, M.; Baker, Will C.; Bellina, F.; Ciazynski, D.; Егоров, С. А.; Kim, K.; Kvitkovič, J.; Lacroix, Benoît; Martovetsky, N.; Mitchell, N.; Muzzi, L.; Nunoya, Y.; Okuno, K.; Polák, M.; Ribani, Pier Luigi; Salpietro, E.; Savoldi, Laura; Sborchia, C.; Takahashi, Yoshikazu; Peide, Weng; Wesche, R.; Zani, L.; Zapretilina, E.

doi:10.1109/tasc.2007.899046

Cited by 7 publications

(5 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Whereas the strand itself is stable at the peak field value, when tested on a barrel, in the PFCI T CS and I C tests, both smooth and sudden transitions occurred, depending on the current level: as an example, it can be seen in figure 3 that the transition was smooth at 'low' current but sudden (within the accuracy/resolution of the available diagnostics, see above) at 'high' current, which is a common feature of both the PFCI and the short sample [11,15]. Both the strand-like performance (in the case of uniform current distribution) and the smooth versus sudden transition at low versus high currents were anticipated by the predictive simulations [16].…”

Section: Performancementioning

confidence: 57%

EU contribution to the test and analysis of the ITER poloidal field conductor insert and the central solenoid model coil

Zanino

Bagnasco

Ciazynski

et al. 2009

Supercond. Sci. Technol.

View full text Add to dashboard Cite

The PFCI is a single-layer solenoid wound from a 45 m long ITER-type NbTi dual-channel cable-in-conduit conductor, designed to be representative of the one currently proposed for the ITER PF1&6 coils. The PFCI, installed in the bore of the ITER central solenoid model coil (CSMC) at JAEA Naka, Japan, and well instrumented from both the thermal hydraulic and the electromagnetic points of view, has been successfully tested in June-August 2008. The test concentrated on DC performance (current sharing temperature and critical current measurements) and AC loss measurements. The results of the analysis of those measurements are reported in the paper, with particular attention to the comparison with the PFCI short sample, which was previously tested in the SULTAN facility. The evolution of the DC performance of the CSMC is also discussed.

show abstract

Section: Performancementioning

confidence: 57%

EU contribution to the test and analysis of the ITER poloidal field conductor insert and the central solenoid model coil

Zanino

Bagnasco

Ciazynski

et al. 2009

Supercond. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…Further details on the coil design [6], strand and cable manufacturing [7]- [11], coil manufacturing [12], short sample test results [5], [13], and supporting analyses to the insert test [14]- [17] can be found in the extensive list of references quoted. [19], [20], with the necessary adaptations to the different operating conditions and PF conductor characteristics [15].…”

Section: The Pf Conductor Insertmentioning

confidence: 99%

“…A large part of the PFI test was hence dedicated to the measurement of the cable AC loss vs. cyclic loading. More details on the genesis and finalization of the test program can be found in [15]- [17].…”

Section: The Pf Conductor Insertmentioning

confidence: 99%

Test Results From the PF Conductor Insert Coil and Implications for the ITER PF System

Bessette

Bottura

Devred

et al. 2009

IEEE Trans. Appl. Supercond.

Self Cite

View full text Add to dashboard Cite

Abstract-In this paper we report the main test results obtained on the Poloidal Field Conductor Insert coil (PFI) for the International Thermonuclear Experimental Reactor (ITER), built jointly by the EU and RF ITER parties, recently installed and tested in the CS Model Coil facility, at JAEA-Naka. During the test we (a) verified the DC and AC operating margin of the NbTi Cable-in-Conduit Conductor in conditions representative of the operation of the ITER PF coils, (b) measured the intermediate conductor joint resistance, margin and loss, and (c) measured the AC loss of the conductor and its changes once subjected to a significant number of Lorentz force cycles. We compare the results obtained to expectations from strand and cable characterization, which were studied extensively earlier. We finally discuss the implications for the ITER PF system. Index Terms-Cable-in-conduit conductors, fusion reactors, Nb-Ti superconducting material, superconducting magnets. I. BACKGROUND ON ITER PF CONDUCTORST HE ITER Poloidal Field (PF) conductors have undergone a significant evolution in the past years. In the original ITER design (2001) the Cable-in-Conduit Conductors (CICCs) were optimized to match the current/field levels in each of the six PF coils [1]. Following recent design reviews, a number of modifications have been introduced [2], leading to the conductor designs detailed in Table I, for the envelope of operating conditions in the PF Coils reported in Table II. The main change with respect to the original design is a reduction in the Cu:nonCu ratio of the low field conductors (PF2 to PF5), implying that the Stekly condition of cryogenic stability [3] is no longer respected. Experiments on subsize conductors [4] have suggested that in the planned regime of operation, and for the expected perturbation spectrum, full cryostability (i.e. a copper fraction corresponding to the Stekly limit) is excessive. In fact, for the conditions considered, it is more convenient to design the conductor for larger temperature margin, increasing the fraction of Nb-Ti, while maintaining the copper fraction to the strict minimum demanded for protection. To achieve the operating requirements of Table II, two main conditions must be met. Firstly, the cable performance must be close to the sum of the projected performance of the individual strands, without the occurrence of the premature quenches often seen in large size Nb-Ti conductors and attributed to current non-uniformity [4], [5] (see also later discussion). In practice, we quantify this first condition using the temperature margin above the operating temperature. The design value of the temperature margin is 1.5 K, with a maximum uncertainty of 0.5 K, which results in a minimum acceptable margin of 1 K.Secondly, all AC loss sources in the cable must be controlled, so to limit the temperature increase due to the heating due to the pulsed operation. In particular, the product of the cable demagnetization factor and coupling time constant, , proportional to coupling loss, must be smalle...

show abstract

“…In Tcs runs, the temperature at which the coil reaches the quench electric field is on average 80 mK higher in the simulation than in the measurements. In spite of the increased difference compared to the other analysed samples, the PFCI simulation results are already much better than the predictions presented in [8,9], where the deviation between prediction and experiment amounts up to more than 0.4 K. Since JackPot has already been proved effective in describing the behaviors of the other analyzed samples, the observed increased error cannot be simplistically attributed to limitations of the code. Instead other factors such as the length of the PFCI winding of several tens of meters combined with a rather poor axial temperature monitoring should be taken into account.…”

Section: Validation Of the Simulation Resultsmentioning

confidence: 68%

“…At this purpose it should be remarked that in spite of the effort spent in the last years in the attempt to model the CICC DC transport behavior, none of the developed models has been able up to now to reach sufficient accuracy in the reconstruction of the V-T curve. While all other existing models are characterized by an accuracy typically of about 0.5 K (depending on the conductor current level), the T cs of all the analyzed samples could be assessed with JackPot within 0.12 K along the entire B and T experimental spectrum [8][9][10]. We believe that the accuracy and credibility of JackPot can be attributed to taking into account all the individual strands inside a CICC (over lengths of tens of meters) in combination with a very detailed model of the joints based on extensive joint measurements and not including any free parameters that could be tuned to match the experimental results.…”

Section: Introductionmentioning

confidence: 99%

Minimum quench power dissipation and current non-uniformity in international thermonuclear experimental reactor type NbTi cable-in-conduit conductor samples under direct current conditions

Rolando¹,

Lanen²,

Nijhuis³

2012

Journal of Applied Physics

View full text Add to dashboard Cite

Abstract. The level of current non-uniformity in NbTi CICCs sections near the joints in combination with the magnet field profile needs attention in view of proper joint design. The strand Joule power and current distribution at quench under DC conditions of two samples of ITER Poloidal Field Coil conductors, as tested in the SULTAN facility and of the so called PFCI Model Coil Insert, have been analyzed with the numerical cable model JackPot. The precise trajectories of all individual strands, joint design, cabling configuration, spatial distribution of the magnetic field, sample geometry and using experimentally determined interstrand resistance distributions have been taken into account. Although unable to predict the quench point due to the lack of a thermal-hydraulic routine, the model allows to assess the instantaneous strand power at quench and its local distribution in the cable, showing the hot spots, once the quench conditions in terms of current and temperature are experimentally known., The analysis points out the relation of the above mentioned factors with the DC quench stability of both short samples and coils. The possible small scale and local electricalthermal interactions were ignored in order to examine the relevance of such effects in the overall prediction of the CICC performance The electromagnetic code shows an excellent quantitative predictive potential for CICC transport properties, excluding any freedom for matching the results. The influence of the local thermal effects in the modeling is identified as being marginal and far less than the generally accepted temperature margin for safe operation.

show abstract

Predictive Analysis of the ITER Poloidal Field Conductor Insert (PFCI) Test Program

Cited by 7 publications

References 18 publications

EU contribution to the test and analysis of the ITER poloidal field conductor insert and the central solenoid model coil

EU contribution to the test and analysis of the ITER poloidal field conductor insert and the central solenoid model coil

Test Results From the PF Conductor Insert Coil and Implications for the ITER PF System

Minimum quench power dissipation and current non-uniformity in international thermonuclear experimental reactor type NbTi cable-in-conduit conductor samples under direct current conditions

Contact Info

Product

Resources

About