Note on the Transmutation Function for Deuterons
J. R. Oppenheimer · M. Phillips
Abstract and summary · read the original at the source · none found
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Two pages in 1935 explained a puzzle in early accelerator data, and the mechanism they named is still one of the two textbook routes chapter 12 needs. Fire a deuteron at a nucleus and, on the simplest picture, the Coulomb barrier should hold it off exactly as it holds off a proton or an alpha particle, so the reaction rate should climb steeply with the deuteron's energy. It does not. Oppenheimer and Phillips point to what makes a deuteron different from a bare charge: it is a loosely bound pair, large for its mass and easily polarized, so as it approaches a nucleus it can be stretched, presenting its neutron to the target while its proton is still held at a distance. The neutron is captured while the proton is repelled away. Because it is the neutron that has to arrive, the Coulomb repulsion is less effective than it is for a proton or an alpha, and the resulting transmutation function rises more slowly with energy. They treat the collision in the adiabatic approximation and report the energy dependence as being in good agreement with experiment.
Dlaczego ma tu znaczenieChapter 12 rests on two pieces of settled nuclear physics — electron screening and this stripping reaction — being enough to explain what the NASA Glenn deuterated-metal experiments report, without anything exotic being invoked. This is the original statement of the second of those two, and it is the reason a deuteron in a lattice can react at energies a bare proton could not.
Co twierdzi
01The starting point is a property of the deuteron rather than of the target: the finite size and ready polarizability of the deuteron change the probability of transmutations involving the capture of the neutron.Abstract, first sentence
Settled physics02The consequence is that the Coulomb repulsion of the nucleus is less effective than it is for alpha particles or protons — the barrier still exists, but a polarized deuteron does not meet it the way a bare charge of the same energy does.Abstract, second sentence
Settled physics03Therefore the corresponding transmutation functions increase less rapidly with deuteron energy than the functions for protons or alpha particles do — which is the measurable signature of the process and the anomaly the paper was written to explain.Abstract, second sentence
Settled physics04The calculation treats the collision by the adiabatic approximation, on the reasoning that the deuteron's internal motion is slow compared with the approach, so the pair has time to stretch as the field of the nucleus rises.Abstract, third sentence
Settled physics05The result was checked against data at the time, not merely proposed: the authors obtain quantitative results for the energy dependence which they state are in good agreement with experiment.Abstract, closing sentence
Settled physics
Przeczytaj · abstract
Abstract
We consider the effect of the finite size and ready polarizability of the deuteron on the probability of transmutations involving the capture of the neutron. These have as a consequence that the Coulomb repulsion of the nucleus is less effective than for alpha-particles or protons, and that the corresponding transmutation functions increase less rapidly with deuteron energy. We treat the collision by the adiabatic approximation and obtain quantitative results for this energy dependence which are in good agreement with experiment.
J. R. Oppenheimer and M. Phillips, Note on the Transmutation Function for Deuterons, Physical Review 48, 500 (1935).
(Abstract only, and the full text was not reachable — see the rights note above. On this site, the NASA Glenn theory paper that invokes this mechanism alongside electron screening is at /library/stm-04df359342.)
Droga do źródła
https://doi.org/10.1103/PhysRev.48.500SOURCE NOT REACHED IN FULL. The article is held by the American Physical Society and is closed: on 2026-09-11 OpenAlex reported open-access status closed with no repository location, and the paper predates every preprint server. What is reproduced below is the authors' own complete abstract as OpenAlex carries it, and the summary and every claim are written from that abstract, which is why each locator says Abstract. The page range and the author line were confirmed independently against the Crossref record. AUTHOR NAME. Crossref and the journal give the second author only as M. Phillips, and that initial is kept here; the OpenAlex record expands it to a different given name, which is why this sheet does not follow it. The mechanism described in this paper is the one the literature calls the Oppenheimer-Phillips process.
Jak cytować
J. R. Oppenheimer, M. Phillips (1935) Note on the Transmutation Function for Deuterons. doi:10.1103/PhysRev.48.500
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