TY - DATA
T1 - Replication package Separation of transport in slow and fast time-scales using modulated heat pulse experiments (hysteresis in flux explained)
PY - 2018/09/19
AU - Matthijs van Berkel
AU - G (Gerd) Vandersteen
AU - H.J. (Hans) Zwart
AU - G.M.D. (Gerrit) Hogeweij
AU - J. (Jonathan) Citrin
AU - E. (Egbert) Westerhof
AU - D. (Dries) Peumans
AU - M.R. (Marco) de Baar
UR - https://data.4tu.nl/articles/dataset/Replication_package_Separation_of_transport_in_slow_and_fast_time-scales_using_modulated_heat_pulse_experiments_hysteresis_in_flux_explained_/12696938/1
DO - 10.4121/uuid:5fcf4247-da0e-4119-adcd-fc90b85b7f03
KW - Heat transport
KW - Hysteresis in flux
KW - Nuclear fusion
KW - Perturbative experiments
N2 - Old and recent experiments show that there is a direct response to the heating power of transport observed in modulated ECH experiments both in tokamaks and stellarators. This is most apparent for modulated experiments in the Large Helical Device (LHD) and in Wendelstein 7 advanced stellarator (W7-AS). In this paper we show that:
1) This power dependence can be reproduced by linear models and as such hysteresis (in flux) has no relationship to hysteresis as defined in the literature;
2) Observations of hysteresis (in flux) and a direct response to power can be perfectly reproduced by introducing an error in the estimated deposition profile as long as the errors redistribute the heat over a large radius;
3) Non-local models depending directly on the heating power can also explain the experimentally observed Lissajous curves (hysteresis);
4) How non-locality and deposition errors can be recognized in experiments and how they affect estimates of transport coefficients;
5) From a linear perturbation  transport experiment, it is not possible to discern deposition errors from non-local fast transport components (mathematically equivalent).
However, when studied over different operating points non-linear-non-local transport models can be derived which should be distinguishable from errors in deposition profile. To show all this, transport needs to be analyzed by separating the transport in a slow (diffusive) time-scale and a fast (heating/non-local) time-scale, which can only be done in the presence of perturbations.
ER -