Why HyperJet Fusion?

Today a number of fusion energy concepts and approaches are being pursued while research conducted in the private sector is increasing. Eventually, humans may find many ways of producing fusion energy. However, the team with a fusion approach that (1) has a low-cost driver, and (2) lends itself to rapid learning, will be the team most likely to achieve fusion first and gain the critical first-mover advantage. Also, as previously explained, a more rapid development pathway for commercial fusion power is required because fusion power is needed to complete the global transition to clean energy before mid-century, together with other sources of clean energy (wind, solar, biomass, geothermal, etc.).

The formulation of the hyperjet fusion approach was guided by the lessons learned from decades of complex plasma physics and fusion energy research. Given the attractiveness of fusion energy, developed countries around the world began to pursue its development immediately after the dramatic demonstration of fusion power in the successful tests of thermonuclear weapons.

A more rapid development pathway for commercial fusion power is required because fusion power is needed to complete the global transition to clean energy before mid-century.

The basic concept to achieve thermonuclear fusion reactions in a controlled manner is to heat a certain amount of hydrogen or its isotopes to temperatures around 100 million degrees in a controllable manner and to confine it for a certain length of time so that more energy is produced by the fusion reactions than the energy used to produce them. At that temperature, all matter exists in a plasma state, a state in which atoms are dissociated into ions and electrons, and whose behavior is governed by the principles of plasma physics.

Over the last 60 years, as a result of the worldwide fusion research, we have developed an extensive knowledge base of plasma science, as well as the engineering capabilities for generating, heating, compressing, confining and manipulating plasma. This vast knowledge and technology base was gained mainly by studying two diametrically opposite and extreme approaches to controlled thermonuclear fusion. At one extreme is magnetic confinement fusion (MCF) which attempts to create a fusion burning plasma at extremely low densities (~1014 ions per cc) and confining it in a steady state by the use of magnetic fields. This approach is exemplified by the tokamak and stellarator. At the other extreme is inertial confinement fusion (ICF) which attempts to create a fusion burning plasma at extremely high densities (~1026 ions per cc) in a pulsed mode on a nanosecond time scale, by compressing a frozen pellet of isotopes of hydrogen with high-intensity lasers, heavy ion beams, or other drivers.

After decades of research, it became clear by the mid-1990’s that creating a burning plasma with either of these two extreme fusion approaches is prohibitively expensive, for reasons rooted in the fundamental principles of plasma physics and engineering. On the one hand, when the plasma density is low, the plasma volume needs to be large in order to keep the loss of thermal energy through its boundaries sufficiently low to create a burning plasma, leading to the use of large amounts of expensive magnetic fields to confine the plasma, as well as costly drivers to heat the plasma. On the other hand, when the plasma density is very high, the heat loss from the plasma is very rapid, and a very high implosion velocity is required, thus requiring drivers with very high power density, with nanosecond pulsed power, which again is extremely expensive.

It became clear that the lowest-cost pathway for practical fusion energy based on thermonuclear fusion reactions is to combine the best features of MCF and ICF in a new class of fusion approaches called Magneto-Inertial Fusion (MIF), aka Magnetized Target Fusion (MTF), and to exploit the intermediate density regime (1018 to 1023 ions per cc). See Figure. It makes use of the magnetic energy confinement of MCF, and the compressional heating and plasma pressure containment by inertia of ICF in a pulsed mode. MIF is indeed a hybrid of MCF and ICF. Using a much higher density plasma than MCF, it reduces the size of the fusing plasma from meter scale to centimeter scale on the one hand. On the other hand, by using a magnetic field in its target plasma and the much lower density than ICF, MIF can use much slower pulsed power technologies (microseconds to milliseconds) to drive the compression. As a result, MIF can be implemented with low-cost drivers, potentially lowering the R&D cost and the fusion reactor cost by up to two orders of magnitude compared to MCF and ICF.

Magneto-Inertial Fusion can be implemented with low-cost drivers, potentially lowering the R&D cost and the fusion reactor cost by up to two orders of magnitude compared to MCF and ICF.

The basic MIF schema is to make use of a material shell (called a liner) to compress a magnetized target plasma to achieve fusion conditions. There are a number of embodiments of MIF, differing in the liners, targets used, and the speed of implosion.

Hyperjet fusion, aka Plasma-Jet driven Magneto-Inertial Fusion (PJMIF), is a modern embodiment of MIF. The key features of hyperjet fusion that make it stand out among the MIF approaches are: (1) the standoff nature of the drivers, (2) the relatively higher implosion velocity (50 km/s to 100 km/s) among the MIF approaches, (3) high shot-rate capability with relatively low cost per shot during R&D, and (4) its open geometry for relatively convenient diagnostics access.

There are potentially several ways of producing these plasma jets. Presently, we are using coaxial plasma guns with contoured shaped electrodes. Unlike lasers, coaxial plasma guns do not require expensive complex optics or ultra-fast pulsed power technology. They are relatively inexpensive.

Unlike tokamak or stellarator fusion, hyperjet fusion does not require large expensive superconducting magnets to confine the fusion-burning plasma. It does not also require large expensive continuous neutral particle beam or microwave heating systems for heating the plasma to fusion conditions. The imploding plasma liner provides the heating of the target plasma to fusion conditions.

The hyperjet fusion open geometry and moderate reactor size allow for convenient and relatively low-cost diagnostic access. In contrast to other magneto-inertial fusion approaches, the driver in hyperjet fusion is located with sufficient standoff distance from the pulsed fusion explosion and thus avoids any hardware destruction. These features allow hyperjet fusion experiments to be conducted at low cost with high shot rates, enabling rapid resolution of technical issues (rapid learning) and thus rapid R&D development. The ability to use highly repetitive rates (~1 Hz) in the eventual power reactor will lead to high utilization factor of the reactor and thus low capital cost of the power plant.

The high implosion velocity of the liner plasma overcomes stability, lifetime and energy confinement time issues of the target plasma.

In terms of fusion reactor engineering, hyperjet fusion also has the following advantages:

  • The topological and geometric layout of the reactor is well suited for fast and economical maintenance.
  • Plasma jets are used for forming both the fuel target and the driver avoiding the costly repetitive destruction and replacement of solid parts during reactor operation.
  • The distance of the reactor wall or “stand-off’ from the fusion ignition increases the lifetime and reduces the maintenance of the reactor vessel. This feature allows the use of a thick liquid wall, thus avoiding a multi-billion-dollar, multi-decade nuclear materials development effort.

The President and CEO of HyperJet Fusion is Dr. Y. C. Francis Thio, who invented hyperjet fusion after a long career in fusion and fusion-related pulsed power research for defense and space applications. He also invented the contour-gap coaxial plasma gun specifically to meet the driver requirements of hyperjet fusion. HyperJet Fusion Corporation builds on the pioneering development conducted at NASA Marshall Space Flight Center, Los Alamos National Laboratory, and HyperV Technologies Corp. This hyperjet fusion research and development has been funded by NASA, DOE Office of Fusion Energy Sciences (FES), and ARPA-E, and represents nearly $28 million in U.S. government investment so far. HyperJet Fusion has inherited all the facilities, equipment and personnel developed by HyperV Technologies for PJMIF. Additionally, the founder and President of HyperV Technologies Corp. Dr. F. Douglas Witherspoon, is now the Vice President and COO of HyperJet Fusion.