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Title: Tokamak two-fluid ignition conditions

ORCiD logo [1];  [2]
  1. Physics Department, Auburn University, Auburn, Alabama 36849, USA
  2. Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627, USA
Publication Date:
Sponsoring Org.:
OSTI Identifier:
Grant/Contract Number:
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 24; Journal Issue: 8; Related Information: CHORUS Timestamp: 2018-02-14 14:34:13; Journal ID: ISSN 1070-664X
American Institute of Physics
Country of Publication:
United States

Citation Formats

Guazzotto, L., and Betti, R. Tokamak two-fluid ignition conditions. United States: N. p., 2017. Web. doi:10.1063/1.4994073.
Guazzotto, L., & Betti, R. Tokamak two-fluid ignition conditions. United States. doi:10.1063/1.4994073.
Guazzotto, L., and Betti, R. 2017. "Tokamak two-fluid ignition conditions". United States. doi:10.1063/1.4994073.
title = {Tokamak two-fluid ignition conditions},
author = {Guazzotto, L. and Betti, R.},
abstractNote = {},
doi = {10.1063/1.4994073},
journal = {Physics of Plasmas},
number = 8,
volume = 24,
place = {United States},
year = 2017,
month = 8

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on July 21, 2018
Publisher's Accepted Manuscript

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  • In this paper a global reactor performance code employing Monte Carlo techniques developed to study the probability of ignition and applied to several configurations of a compact, high-field ignition tokamak to determine the relative benefits of raising the plasma current and peaking the density profile. Probability distributions for the critical physics parameters in the code are estimated using existing experimental data. An energy confinement scaling representing a 1 to 2.5 times improvement over the L mode is assumed; the range of this multiplier was chosen to reflect the uncertainty in extrapolating the energy confinement time to the high-field ignition regime.more » Even with fairly broad input probability distributions, the probability of ignition improves significantly with increasing plasma current and density profile peaking. Raising the plasma current by 2 MA has about the same impact as raising the peak-to-average density ratio from {approx}1 to {approx}3. With either this density peaking or a plasma current {ge}11 MA, the probability of ignition is computed to be {ge}40%. In other cases, values of Q (the ratio of the fusion power to the sum of the ohmic and auxiliary input powers) of the order of 10 are generally obtained. Comparisons of our empirically based confinement assumptions with two theory-based transport models yield conflicting results.« less
  • In this paper plans for alpha-particle experiments on the Tokamak Fusion test Reactor and Compact Ignition Tokamak are described. The main physics issue is whether alpha particles are confined long enough to thermalized. Some of the diagnostic methods required to measure alpha-particle confinement are briefly described.
  • In this paper the current driven by neutral beam injection is calculated for three different reactor designs: the Tokamak Ignition/Burn Experimental Reactor II (TIBER-II), the U.S. option for the International Thermonuclear Experimental Reactor (ITER-US), and the International Tokamak Reactor (INTOR). The sensitivity of the current drive efficiency to plasma and beam parameters is studied, and general conclusions are drawn.
  • The flame regimes of ignition and flame propagation as well as transitions between different flame regimes of n-heptane-air mixtures in a one-dimensional, cylindrical, spark assisted homogeneously charged compression ignition (HCCI) reactor are numerically modeled using a multi-timescale method with reduced kinetic mechanism. It is found that the initial mixture temperature and pressure have a dramatic impact on flame dynamics. Depending on the initial temperature gradient, there exist at least six different combustion regimes, an initial single flame front propagation regime, a coupled low temperature and high temperature double-flame regime, a decoupled low temperature and high temperature double-flame regime, a lowmore » temperature ignition regime, a single high temperature flame regime, and a hot ignition regime. The results show that the low temperature and high temperature flames have distinct kinetic and transport properties as well as flame speeds, and are strongly influenced by the low temperature chemistry. The pressure and heat release rates are affected by the appearance of different flame regimes and the transitions between them. Furthermore, it is found that the critical temperature gradient for ignition and acoustic wave coupling becomes singular at the negative temperature coefficient (NTC) region. The results show that both the NTC effect and the acoustic wave propagation in a closed reactor have a dramatic impact on the ignition front and acoustic interaction.« less