Positron Dynamics will use Krypton isotopes to generate positrons. They would breed more Krypton isotopes. They sidestep the issue of antimatter storage. It would take 10 school buses of volume at the Brillouin limit to trap 1 microgram.
They are slowing the positrons that are generated.
Krypton 79 isotope to generate hot positrons.
Use their system to moderate the positrons so they can be used.
They then use the Positrons to catalyze nuclear fusion. Neutrons from nuclear fusion can then breed more Krypton 79.
They have done momentum transfer and deuterium loading experiments.
There would be 1-10% momentum transfer from catalyzed fusion propulsion.
They need one trillion positrons to generate nuclear fusion events according to the Lawson Criteria.
Energy balance and 2-D pic models indicate maybe 100 billion positrons would be needed.
They have worked on the isotope breeding. They needed to get the Krypton densified. The amount of Krypton 79 that can be generated is limited by source geometry.
They have a system designed for an 100-ton asteroid capture mission with a delta-V of 60 kilometers per second. It would be 20 times lighter than NASA solar electric mission.
They need to efficiently create more isotope to get more positrons instead of using magnetic storage.
They are working on a bragg laser mirror using aerogels. Their processes for positron moderation overlap with making bragg laser mirrors. Light mirrors for laser sail propulsion.
They are also working to get to 100 watts per kilogram for a nuclear battery using aerogel and graphene layers.
SOURCES – Live Coverage of Ryan Weed Positron Dynamics presentation at Space Access 2019, Youtube presentation and Positron Dynamics
Written by Brian Wang, Nextbigfuture.com