{'fraction_non_alphanumeric': 0.018830525272547076, 'fraction_numerical': 0.0, 'mean_word_length': 5.011904761904762, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A model for tokamak confinement

A model is proposed for confinement scaling in tokamaks. This model is drawn from a detailed study of TFR discharges and consists of a combination of neoclassical and anomalous fluxes and a fully non-coronal impurity model with anomalous impurity diffusion. The anomalous diffusion coefficients scale as . An improved treatment of transport due to sawtooth oscillations is also included in the model. A detailed comparison between model predictions and TFR Ohmic-heating results is discussed. Discrepancies are resolved between the neutral-gas component of this model and experiment. The model is checked with a high-density case from Alcator, where neoclassical contributions are stronger than the anomalous terms, and also with a hollow-Te-profile case presented by the DITE group. In the latter case, impurity effects are dominant. The model is successful in these comparisons, and so projections are given of the performance of Ohmically heated plasmas in JET and IGNITOR.