Historical research guide · 0901 · 2009
Wide-Ranging Studies on the Emission of Neutrons and Tritium by LENR Configurations: An Historical Review of the Early BARC Results
Mahadeva Srinivasan
In one minute
Mahadeva Srinivasan ran the Neutron Physics Division at India’s Bhabha Atomic Research Centre when the Fleischmann and Pons announcement arrived in March 1989. Within weeks twelve teams and about fifty BARC scientists were loading palladium and titanium with deuterium — some by electrolysis, some by soaking the metal in deuterium gas or firing it in a plasma — and watching for the two signatures a nuclear reaction would leave behind: neutrons and tritium. This chapter is Srinivasan’s own account, twenty years later, of what that campaign found. Three results carry the weight. Tritium appeared far more often than neutrons, by something like ten million to one, which is not the ratio ordinary deuterium fusion produces. A share of the neutrons arrived not singly but in bursts, tens to hundreds released together. And the activity sat in tiny, sharply bounded spots on the metal rather than spread evenly through it. Srinivasan’s reading of the pattern: micro-scale nuclear events firing in selected sites of the lattice.
Connection
Chapter 12 rests on the claim that a metal lattice loaded with deuterium can host nuclear reactions, and the BARC campaign is the largest early body of evidence for it gathered inside one laboratory — twelve independent teams, reactor-grade neutron and tritium instrumentation, and two nuclear signatures measured at once. The neutron-to-tritium ratio and the burst structure are still the two numbers any lattice model has to explain.
From the source
On receipt of news of the Fleischmann and Pons announcement in March 1989, scientists at the Bhabha Atomic Research Centre loaded samples of palladium and titanium with deuterium using both electrolytic methods and gas and plasma absorption techniques. Twelve research groups and fifty scientists were involved, and clear evidence was accumulated for the generation of neutrons and tritium.Chapter abstract, opening sentences; ACS Symposium Series 1029, chapter 3, pages 35 to 57
Tritium production is much more probable than neutron production, with the neutron-to-tritium yield ratio being about one to ten million. Ordinary deuterium-deuterium fusion produces the two branches in roughly equal numbers, so a ratio this lopsided is the campaign’s central anomaly. The earlier ICCF-1 overview gives the measured spread across twenty-two electrolytic experiments, whose cathode surface areas ranged from a tenth of a square centimetre to three hundred, as one part in a million down to one part in a billion.Chapter abstract, finding (a); Iyengar and Srinivasan, ICCF-1 overview, abstract
A fraction of the neutrons released comes in the form of bursts of tens to hundreds of simultaneously emitted neutrons, rather than as a steady trickle. The statistical companion paper puts numbers on it from six experiments analysed by multiplicity spectrum in twenty-millisecond windows: about ten to twenty-five per cent of the neutrons produced are emitted in bunches of four to six hundred neutrons each.Chapter abstract, finding (b); Srinivasan, Shyam, Degwekar and Kulkarni, Statistical Analysis of Neutron Emission in Cold Fusion Experiments, ICCF-1, abstract
The nuclear reactions responsible appear to be occurring in highly localized hot spots in the host metal rather than uniformly through the bulk. Autoradiography of deuterated titanium and palladium at BARC resolved the tritium into a scatter of individual spots roughly a millimetre across, each carrying its own activity, which is what turned a bulk measurement into a map.Chapter abstract, finding (c); Iyengar and Srinivasan, ICCF-1 overview, gas-phase section
In the BARC electrolysis results the first bursts of neutrons and tritium arrived on the very first day of electrolysis, in eight of eleven cells, when only a few ampere-hours of charge had been passed. That timing separates the BARC record from the months-long loading campaigns run elsewhere, and it is the practical reason the group could measure both signatures on the same cell.Iyengar and Srinivasan, ICCF-1 overview, abstract
What to watch: Srinivasan reads the whole pattern — the tritium excess, the neutron bunches and the localization together — as evidence for some type of micro-nuclear explosion in selected lattice sites, and that is the hypothesis the field still has to confirm or replace. The measurement that would settle it is the one BARC was already building toward: simultaneous, time-resolved neutron and tritium counting on a single site, so that the multiplicity of one burst and the tritium it leaves can be tied to the same event.Chapter abstract, closing sentence; Rout and colleagues, Fusion Technology 19, 391, closing paragraph
The way in
https://doi.org/10.1021/bk-2009-1029.ch003How to cite it
Mahadeva Srinivasan (2009) Wide-Ranging Studies on the Emission of Neutrons and Tritium by LENR Configurations: An Historical Review of the Early BARC Results doi:10.1021/bk-2009-1029.ch003