A Method for Active Space Charge Neutralization in an Inertial Electrostatic Confinement (IEC) Nuclear Fusion Device
A Method for Active Space Charge Neutralization in an Inertial Electrostatic Confinement (IEC) Nuclear Fusion Device

Author: Brendan Sporer

Publisher:

Published: 2017

Total Pages:

ISBN-13:

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Recent inertial electrostatic confinement (IEC) fusion concepts are discussed and their shortcomings noted. Ion space charge is substantiated as a significant hindrance to high efficiencies, so a method for space charge neutralization in an ion-injected IEC device is proposed. An electrostatically- plugged magnetic trap is used to confine electrons in the core region of a planar electrostatic trap for ions. The electrons act to dynamically neutralize the space charge created by converging ions for the purpose of increasing achievable core density and fusion rates. An electrostatic trap utilizing this method of neutralization is termed the plasma-core planar electrostatic trap, or PCPET. COMSOL Multiphysics 4.3 is used to model the electromagnetic fields of the PCPET and compute lone ion and electron trajectories within them. In the proper configuration, ions are shown to be stably confined in the trap for many hundreds of oscillations, potentially much longer. Electrons are confined virtually infinitely in the central electrostatically-plugged cusp. For both species, upscatter into source electrodes seems to be the dominant loss mechanism. Adjusting the electron energy and behavior in the core to provide the optimum neutralization for ions is discussed. Ion synchronization behavior can be controlled with RF signals applied to the anode. Two operational modes are identified and discriminated by the state of ion synchronization. Further experimentation is needed to determine which mode produces the optimal neutralization and fusion rate. An experimental prototype PCPET is constructed out of 3D-printed PLA and machined aluminum.

Performance Impact of Ion Sources in Inertial Electrostatic Confinement Devices
Performance Impact of Ion Sources in Inertial Electrostatic Confinement Devices

Author: Alexandru D. Calburean

Publisher:

Published: 2020

Total Pages: 48

ISBN-13:

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In order to improve the performance of Inertial Electrostatic Confinement (IEC) based fusion devices, so as to improve their effectiveness as low cost, portable neutron sources, a novel use of ion sources is proposed as a means of increasing fusion reaction rate at similar power levels. This paper aims to determine the success and practicality of the proposed use type for ion sources and characterize the IEC device in question, in terms of performance, and neutron emission. The application outlined aims to improve upon the performance of IEC devices with an anode layer ion source. The above-mentioned approach was evaluated by first conditioning the IEC fusion device in question. Then a neutron flux baseline was recorded as a metric for performance, and to evaluate the assumption of neutron emission isotropy in the device. Then an ion source was installed in the chamber, and the system was once again conditioned in the same manner. A similar baseline reading and analysis was done to ensure a correct comparison could be made between performance with the ion source turned on and off. Next the system was run with the ion source at full power to allow for further characterization of the performance and stability of the device. Finally, a last run was carried out with the ion source properly tuned, and results were compared to both baseline runs. It has been shown that there is a potential performance gain from operation with an ion source, both in terms of system stability and improved neutron emission. Across all run campaigns, the assumption of isotropic emission was shown to be a poor representation of the actual emission. With a higher degree of certainty, it has been shown that operation with an ion source serves to reliably exaggerate the anisotropy found in baseline campaigns.

Instability Studies on a Spherical Inertial Electrostatic Confinement
Instability Studies on a Spherical Inertial Electrostatic Confinement

Author: Hyung Jin Kim

Publisher:

Published: 2006

Total Pages: 154

ISBN-13: 9781109885255

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The spherical inertial electrostatic confinement concept offers an alternative fusion plasma confinement scheme, where charged particles are accelerated and confined electrostatically with a series of biased spherical concentric electrodes. The inertia of the accelerated ions compresses the ions and builds up the space charge at the center of the cathode grid. The space charge of the ions attracts electrons which in turn accumulate a space charge. The accumulation of collective space charge creates a series of deep "virtual" electrostatic potential wells which confine and concentrate ions into a small volume where an appreciable number of nuclear fusion reactions could occur. It is very attractive for a power plant due to its mechanical simplicity and high power-to-mass ratio. However, its beam-plasma interactions are not clearly understood.

An Innovative Accelerator-driven Inertial Electrostatic Confinement Device Using Converging Ion Beams
An Innovative Accelerator-driven Inertial Electrostatic Confinement Device Using Converging Ion Beams

Author:

Publisher:

Published: 1999

Total Pages: 8

ISBN-13:

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Fundamental physics issues facing development of fusion power on a small-scale are assessed with emphasis on the idea of Inertial Electrostatic Confinement (IEC). The authors propose a new concept of accelerator-driven IEC fusion, termed Converging Beam Inertial Electrostatic Confinement (CB-IEC). CB-IEC offers a number of innovative features that make it an attractive pathway toward resolving fundamental physics issues and assessing the ultimate viability of the IEC concept for power generation.

Improved Lifetimes and Synchronization Behavior in Multi-grid Inertial Electrostatic Confinement Fusion Devices
Improved Lifetimes and Synchronization Behavior in Multi-grid Inertial Electrostatic Confinement Fusion Devices

Author: Thomas John McGuire

Publisher:

Published: 2007

Total Pages: 254

ISBN-13:

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A high output power source is required for fast, manned exploration of the solar system, especially the outer planets. Travel times measured in months, not years, will require high power, lightweight nuclear systems. The mature nuclear concepts of solidcore fission and fusion Tokamaks do not satisfy the lightweight criteria due to massive radiators and magnets respectively. An attractive alternative is Inertial Electrostatic Confinement fusion. This extremely lightweight option has been studied extensively and to date has produced significant fusion rates of order 1010 reactions per second, but at low power gains, no higher than Q = 10-4. The major loss mechanisms for the state-of-the-art IEC are identified via a detailed reaction rate scaling analysis. The use of a single cathode grid causes short ion lifetimes and operation at high device pressure for simple ion generation both fundamentally limit the efficiency of these devices. Several improvements, including operation at much lower pressure with ion guns and the use of multiple cathode grids, are verified with particle-in-cell modeling to greatly improve the efficiency of IECs. These simulations show that the greatly increased confinement allows for the development of significant collective behavior in the recirculating ions. The plasma self-organizes from an initially uniform state into a synchronized, pulsing collection of ion bunches.