We’re a long way from knowing how to put antimatter to work in starship engines, but developments in this field are well worth following. Even in the short term, designs like Steven Howe’s antimatter sail hold rich promise for shortening travel times to the outer Solar System and for interstellar precursor missions. Howe’s sail would embed uranium-235 in the sail and let antihydrogen released from the spacecraft initiate a powerful fission reaction.
A major obstacle in building such designs is figuring out how to ramp up production of antimatter. But as we work such issues out, the Alice in Wonderland world of antimatter research continues to prove fascinating in its own right. Thus the word out of CERN that physicists have found a way to make matter and antimatter combine — briefly, to be sure — into a extremely unstable substance called protonium.
Call it ‘anti-chemistry.’ The work at CERN had been dedicated to producing antihydrogen. Just as hydrogen is made up of protons and electrons, anti-hydrogen is formed from antiprotons and anti-electrons, or positrons. But a bit of the protonium hybrid was created at the same time. The hope is to produce larger quantities of the stuff, providing a unique testbed for particle physics.
And exactly what is protonium? According to this story in Chemistry World, it is antiprotonic hydrogen, a composite of a negatively charged antiproton paired with a positively charged proton. To produce it, CERN’s Athena collaboration cools antiprotons down to the point that they can be caught in an electrostatic trap. The reaction occurs between the antiprotons and H2+ ions, which consist of two hydrogen atoms missing one electron. The result is protonium, with a neutral hydrogen atom left over.
Learning more about the interactions between particles and antiparticles should reinforce our thoughts on some of the fundamental theories of particle physics. And perhaps those evanescent reactions will also help us learn how to produce antimatter in larger quantities, not to mention tutoring us on the best methods of storage. Steve Howe’s antimatter sail contains some exotic storage methods indeed, using anti-hydrogen pellets in micro-traps. See his Phase II study “Antimatter Driven Sail for Deep Space Missions.” at NASA’s Institute for Advanced Concepts (NIAC) for an analysis of this ingenious method.
Would nice if we could avoid mucking around with antimatter. Still working on that inverse baryogenesis machine…
Adam
Even the NIAC paper doesn’t answer the basic question: The antimatter reaction produces particles of high enough energy (mostly photons?) — and how much of the total energy goes into directed thrust? If the particles are energetic enough, they’ll presumably radiate in all directions, giving no net thrust.
This demands a detailed calculation. One of NIACs problems is their studies don’t address fundamentals often enough, jumping instead to engineering details. This has snared them many times before.
Don’t believe from what I’ve read that anti-protons are a stable particle. Maybe something like a neutron in a “vacuum” that has a half-life of about 11 minutes. I would be surprised if an anti-proton could last that long. The only reason I believe we can store them is because we inadvertantly re-enforce their spin by continuous acceleration. Still they slowly “evaporate” often without detected EM radiation. Positrons, on the other hand, once captured can be stored magnetically without significant loss and such losses can be traced to gamma-radiation– so it appears to be a stable particle.
Gregory, I also believe as you suggested that there would be a real problem with directing matter anti-matter interactions for propulsion. To overcome this I proposed using oxygen nuclei as a reactant intermediary that could be split by the gamma-rays from this reaction, causing a non-chain reactive nuclear fission which might provide, if properly channeled, bountiful thrust.
This seemingly could be done with just positrons, which appear to be easier/ cheaper to produce/ handle/ store/ contain/ manipulate. Probably CERNS Protonium research won’t hurt anything–much.
Adam, Like you I’m not super excited about anti-matter propulsion, especially involving anti-protons. It does have the weight factor advantage of the fuel, but not if the containment factor is considered. Like I mentioned before, I prefer particle beams to the craft for fuel, or maybe an Inverse Baryogenesis Machine. This/ your invention Sounds cool to me! Are there details?
Your friend forrest
Why shouldn’t an antiproton be a stable particle? Sure it annihilates when it comes into contact with matter, but that involves an interaction. Last I heard, the lower limit on the antiproton lifetime is of the order of a million years or so from astrophysical constraints, or tens of thousands of years from laboratory measurements (derived from reaction cross sections, etc.). Antiprotons are probably stable, unless the mechanism for the matter/antimatter asymmetry has something to do with it.
forrest, yes i agree positrons do seem better when it comes to propulsion.also matter anti matter,imho, shows promise too,but as with all things some problems must be worked out first. “some problems” i have a gift for understatement.respectfully yours george
Hi Folks;
Regarding exotic forms of matter/antimatter combinations, it occured to me to mention the possibility of stable bound states of other combinations of quarks besides the proton composed of two up quarks and one down quark and the nuetron composed of two down quarks and one up quark which together make up nuclie with atomic masses of two or greater.
Another option for matter/antimatter materials is that of strangelet and antistrangelet bound states wherein a strangelet would be made of roughly equal numbers of up, down, and strange quarks and anti-strangelets made of roughly equal numbers of antiup, antidown, and antistrange quarks.
Perhaps a bound stable state of Z- and Z+ bosons which have a mass of 91.1876±0.0021 GeV/(C EXP 2) could be produced even though the weak force bosons have a short half life, at least by themselves. Since the apparent cross sectional width as a wavepacket of a particle is inversely related to its mass, any stable bound state of a Z- and Z+ boson might be 1 million times denser than that of protonium or possibly even 1 million times denser than the atomic atomic nucleus.
Another possible super dense material might be composed of a ball of pure strong nuclear force energy in the form macroscopically masses glueballs or material made of gluons which have a stickyness about them and interact in a non-linear fashion.
Thanks;
Jim