Japan Atomic Energy Agency

Last week we visited the Japan Atomic Energy Agency (JAEA) in Naka. The visit was related to my work here, studying the concept of microwave propulsion for future space transportation systems.

The core of the facility is the JT-60 Tokamak reactor. The Tokamak is the reactor type also foreseen for the ITER project. The goal is to achieve a Deuterium-Tritium fusion reaction as a “clean” future energy source. The high energy plasma which is confined inside the Tokamak reactor is heated by high power microwave emitters. The so called Gyrotrons of this facility have a power output of 1 GW (which means more than a million times the power of a typical kitchen microwave).

JT-60 Reactor (sorry for the reflections on the glass)



ITER Tokamak Reactor (source: Wikipedia)

As part of a cooperation between JAEA and the University of Toyo a Gyrotron is occasionally used for the microwave propulsion experiments. Those high energetic microwaves are reflected and focused by a parabolic dish. In the focal point the high energy density converts the ambient air to plasma. The plasma then creates a detonation wave leaving the vehicle, which generates thrust.



1 MW Gyrotron

Since this kind of beamed energy propulsion (BEP) uses ambient air as propellant and requires no on-board fuel for the atmospheric flight the vehicle can be potentially much lighter and therefore more cost efficient than a conventional rocket. At least that is what we hope…