The Chemistry of Antihydrogen.

[NNadir]

Well it looks like they're making antihydrogen over at CERN, Europe being a place to which scientists can escape the dismantling of science in the US. (One of the authors is American, but look for him to be gone.)

I stumbled across this one while looking for a paper on the vapor pressure of strontium metal, and I just had to reference it.

- Zammit, Mark C.; Baker, Christopher J.; Jonsell, Svante; Eriksson, Stefan; Charlton, Michael Antihydrogen chemistry Physical Review A 111, 5, 2025

The abstract:

A survey of antimatter reactions is presented, including the formation of the antihydrogen atom and anionic, cationic, and molecular species by collisional and radiative processes. Our approach is rooted in the detailed knowledge available for many matter counterpart (hydrogenic) reactions, due to their importance in controlling early Universe chemistry. We point out that the availability of trapped antihydrogen at densities similar to those pertaining to the epoch of hydrogen chemistry will soon be available. In addition, using modern atomic physics techniques, it should be feasible to control antimatter in the laboratory to facilitate antihydrogen chemistry. Our purpose is to summarize what is known from hydrogen chemistry that is of relevance for antimatter and to indicate, based on possible reaction rates, which processes may be fruitful to pursue to create new antimatter entities as probes of fundamental symmetries. We include antihydrogen, positrons, and antiprotons in our discussion and additionally the electron due to its propensity to form positronium and perhaps to participate in certain reactions. We attempt to indicate whether further theoretical/computational work is necessary to add to the assessment of reaction rates, and we discount processes where the projected rates are too low to be of interest, given foreseeable experimental capabilities.

The full paper has a lot of symbols not accessible from the DU editor, so here's a graphic capture of some text:



Looks like fun, doesn't it?

I could make some jokes about the fossil fuel greenwasher here who carry on about hydrogen as if it were a source of energy, rather than a way to waste primary energy - hydrogen is made from fossil fuels - but I won't.

[lapfog_1]

1. for once we agree totally

"hydrogen as if it were a source of energy"

Very true... unless there is a source ( readily available in the earth ) of pure Hydrogen... Hydrogen is an energy carrier ( sort of like a bulky battery ), not a source.

BTW, when antimatter contacts matter, the resulting reaction would be net no energy ( given the energy required to make the antimatter hydrogen )? or even negative. Correct?

[NNadir]

2. CERN consumes about 5 Petajoules of energy per year.

The energy comes from the French grid, one of the cleanest grids in the world.

How much went into this particular experiment is unknown to me. However, without having the paper before me, I recall that the antihydrogen was limited to a few atoms. The annihilation energy would be pure gamma radiation when the antihydrogen was released from the magnetic field and would not be recoverable in any case, and otherwise trivial. I'm quite sure the entire process obeyed the unpopular but irrevocable 2nd law of thermodynamics in spades.

I'm glad to agree with you on something although I'm unfamiliar with you and thus don't know of disagreements we may have had.

The "green hydrogen" cults have been around for half a century and they are pernicious inasmuch as they, among other pop fantasies, are designed to preclude real action on energy issues. Hydrogen is a very dirty enterprise.