Author: Miklos PorkolabPublisher:
ISBN:
Category :
Languages : en
Pages : 4
Book Description
Electron Cyclotron Heating Studies of the Compact Ignition Tokamak (CIT)
Author: Miklos PorkolabFY90 Milestone Report for the CIT (Compact Ignition Tokamak) Project
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 5
Book Description
Estimates of the localizability of electron-cyclotron heating power are made for the Compact Ignition Tokamak. A particular heating scenario is examined, namely, the fundamental O-mode, injected nearly perpendicular to the toroidal magnetic field. The absorption depth due to finite T{sub e} is very small, about 1 cm, near the q = 2 surface. Absorption is even better localized near q = 1. Several issues that might lead to degraded localizability are reviewed. Use of an intense, pulsed microwave source is the only issue with a possibly significant impact. 3 refs.
The Compact Ignition Tokamak and Electron Cyclotron Heating
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The CIT will benefit from auxiliary heating of 10 to 40 MW. The schedules of both the CIT construction project and the operating plan contain adequate time to develop and implement ECH systems based on the gyrotron and the induction free electron laser (IFEL). Each approach has advantages and is the object of R and D at the level of many millions of dollars per year. While the gyrotron is further advanced in terms of power and pulse length achieved, rapid progress is scheduled for the IFEL, including experiments on tokamaks. Plans of CIT, gyrotron, and IFEL make 1992 an appropriate time frame to commit to one or both systems. 12 refs., 8 figs., 2 tabs.
Scattering and Localizability of ECH (electron-cyclotron Heating) Power in CIT (Compact Ignition Tokamak).
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 4
Book Description
The theory of scattering by drift-wave density fluctuations is applied to electron-cyclotron heating (ECH) in the Compact Ignition Tokamak (CIT). It is found for CIT that the scattering angles are small and have a Gaussian distribution. An analytic result is given for the average number of scattering events suffered by a ray during propagation through the turbulence layer; this average number is 1.3 for the turbulence level expected in CIT. Localizability of ECH power in CIT is also studied for two choices of steering mirror. Better access to outer flux surfaces and better localization is achieved if the power is steered within a poloidal plane. 7 refs., 3 figs.
Combined Electron Cyclotron Ray Tracing and Transport Code Studies in the Compact Ignition Tokamak
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 4
Book Description
The Compact Ignition Tokamak (CIT) operating scenario is envisaged to consist of a start-up phase in which the toroidal magnetic field (B{sub T}), plasma current (I{sub P}) and central electron density (n{sub e}(0)) are simultaneously ramped, followed by a burn cycle and a ramp down cycle. Electron cyclotron radio-frequency (ECRF) power at fixed frequency is ideally suited to heating during the ramp up phase of CIT. The angle of injection of the incident microwave beam can be varied as the toroidal field is ramped, so as to maintain central rf-power deposition. Furthermore, since the EC wave is a propagating mode in vacuum, relatively high power densities can be easily coupled into a compact device. Finally, we note that recent advances in source technology makes ECR heating at (280--310) GHz a viable option. In order to realistically simulate this ramp up scenario, a combined code has been developed in which ECRF ray tracing and absorption, and MHD equilibrium calculation, and thermal and particle transport are treated self-consistently. Previous studies of electron cyclotron resonance heating in CIT were carried out using model profiles of rf absorption based on stand-alone ray tracing and absorption calculations. In addition, these studies held the plasma current, toroidal magnetic field, and density constant in time. In the present work, a time variation in these plasma quantities is imposed and ECRF power deposition is re-calculated during rf injection so as to more realistically and self-consistently simulate ECH-assisted start-up in CIT. The most recent CIT configuration calls for a toroidal field ramp to 11T. Thus, the present studies consider the use of an ECRF source frequency of 308 GHz, with EC waves launched in the ordinary mode of polarization.
Heating the Compact Ignition Tokamak (CIT).
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 12
Book Description
The proposed CIT starts operation in the late 1990's with 20 MW of rf heating power. The tokamak and facility are to be designed to accommodate 50 MW auxiliary heating. The heating methods new being considered are ion cyclotron heating (ICH) and electron cyclotron heating (ECH). Aspects of these systems are described, and the choice of power level and type is discussed. 18 refs.
The Compact Ignition Tokamak and Electron Cyclotron Heating
Author: D. W. IgnatPlanning for US Ion Cyclotron Heating Research Relevant to the Compact Ignition Tokamak and Alcator C-Mod
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Ion cyclotron heating (ICH) has been chosen as the primary method for providing auxiliary heating power to the plasma in the Compact Ignition Tokamak (CIT). Sustained progress in ion cyclotron range of frequencies (ICRF) heating experiments, together with supporting technology development, continues to justify selection of this technique as the preferred one for heating CIT to ignition. However, the CIT requirements are sufficiently different from existing achievements that continued experimentation and development are needed to meet the goals of the CIT experiment with a high degree of reliability. The purpose of this report is fourfold: (1) to review briefly the physics and technology research and development (R and D) needs for ICH on CIT, (2) to review the status of and planned programs for ICH on US and international machines, (3) to propose a unified ''mainline'' R and D program specifically geared to testing components for CIT, and (4) to assess the needs for experiments including C-Mod, the Tokamak Fusion Test Reactor (TFTR), and DIII-D to provide earlier information and improved probability of success for CIT ICH. 4 refs., 4 figs., 5 tabs.
Electron Cyclotron Assisted Startup and Heating Scenarios in the Compact Ignition Tokamak
Author: Miklos PorkolabPhysics Aspects of the Compact Ignition Tokamak
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The Compact Ignition Tokamak (CIT) is a proposed modest-size ignition experiment designed to study the physics of alpha-particle heating. The basic concept is to achieve ignition in a modest-size minimum cost experiment by using a high plasma density to achieve the condition of ntau/sub E/ approx. 2 x 102° sec m−3 required for ignition. The high density requires a high toroidal field (10 T). The high toroidal field allows a large plasma current (10 MA) which improves the energy confinement, and provides a high level of ohmic heating. The present CIT design also has a gigh degree of elongation (k approx. 1.8) to aid in producing the large plasma current. A double null poloidal divertor and a pellet injector are part of the design to provide impurity and particle control, improve the confinement, and provide flexibility for impurity and particle control, improve the confinement, and provide flexibility for improving the plasma profiles. Since auxiliary heating is expected to be necessary to achieve ignition, 10 to 20 MW of Ion Cyclotron Radio Frequency (ICRF) is to be provided.