Inquiring Minds

Questions About Physics



My name is Josh Epstein. I am a high School Student at Paola High School in Kansas. I was viewing your page on Antihydrogen and I had a few questions. If you are not qualified to answer these questions, please refer this E-Mail to one wyho can.

  1. What is the next logical step in the development of antihydrogen as a power source.
  2. Would the same relative makeup of a compound have to be duplicated in the "antii-sense" to make it susceptible to m/am annihalation? I.E. To annihalate water, would -H2o have to be created?
  3. In regards to the LEAR, how is it that the bending magnet has the same effects on antihydrogen as it would on normal hydrogen?
Thank you very much.

Josh Epstein

Dear Josh,

Thanks for these great questions.

  1. The primary need in order to use antimatter as a power source is to create more antiprotons. Well if you want to use antihydrogen as the power source. Presently, antiprotons can only be made by smashing very high energy particles (usually protons) into a target and capturing the antiprotons into a beam. Our experiment creates the antihydrogen at the same energy as the antiproton was created. Other experiments have been decelerating the antiprotons to low energy and have been struggling to make low energy antihydrogen. In any case, antiprotons are extremely expensive to produce. Each protons can only produce 10-5 of an antiproton (0.00001). Also to create the high energy proton, a huge amount of energy is needed to accelerate it up to these high energies. Various researchers have talked about using the antiprotons as an energy source but you must balance the equations. If it takes me 100,000 Egyptian laborers to build the pyramids so that one pharoah can put a windmill on top to generate energy so that he can heat his coffee, is that really energy production ? In any case, there is potential, but the implementation needs a lot of work.

  2. Yes, you need the exact antimatter counterpart of any particle in order to annihilate it into pure energy (photons). An electron needs an antielectron, a helium needs a antihelium. This is understood both theoretically and experimentally.

  3. I don't know what you mean about the effect of the magnet. The primary effect is that a magnetic field bends the trajectory of particles which have charge. Antihydrogen itself has no electric charge so there is no effect on it (to first order). After the antiatom is ionized, the two particles which it consisted of, the positron annd antiproton continue on the flight path. Both are charged (oppositely) and this will bend in the magnet in opposite directions but by different amounts since their masses are vastly different.

    Now the magnetic field can ionize the atom because, the field looks like an electric field to a very fast particle. The electric field causes the positron to tunnel out of the potential well formed by the binding. This happens to hydrogen to the same degree as it does for antihydrogen since the masses of particle and antiparticle counterparts are the same to within our experimental resolution. I suppose there could be a very small difference but it is hard to think of a mechanism. In any case, this is the real next phase for antihydrogen research, studying the dynamics of the anti-atomic system. We hope to find the same atomic orbitals/energy levels as hydrogen but I guess it would be even more exciting to find a difference.

Glenn Blanford
Fermilab Public Affairs,
Fermilab Experiment E862

Back to Questions About Physics Main Page

last modified 12/15/1997