STM-D-0546Paper1991Published and peer-reviewed

Detection of High Tritium Activity on the Central Titanium Electrode of a Plasma Focus Device

R. K. Rout · M. Srinivasan · A. Shyam · V. Chitra

Summary and citation · read the original at the source · none found

In one page

A plasma focus is a small, violent machine: a capacitor bank dumps into coaxial electrodes, a sheet of current sweeps up the gas ahead of it, and the sheet collapses into a pinch a few millimetres across that reaches ten million degrees for a few tens of nanoseconds. The BARC team in Bombay ran theirs on deuterium at two kilojoules and then looked at something nobody usually looks at — the titanium rod at the centre, which gets scorched, cooled and bombarded with deuterium ions on every shot. It had become radioactive. One electrode carried about 392 microcuries of tritium, roughly ten thousand million million atoms, after sixty shots. Rout, Srinivasan, Shyam and Chitra work through the ordinary explanations and find each one short by orders of magnitude: the gas was not contaminated at that level, and the fusion the machine is known to do could not have made or trapped that much. Their conclusion is that the deuterium-loaded titanium lattice itself is doing something.

Why it matters hereThis is chapter 12’s claim made in chapter 9’s hardware: the anomaly shows up not in a quiet electrochemical cell but on the electrode of a pulsed-power plasma machine, loaded with deuterium by the discharge itself. It is also the single BARC result Srinivasan singles out in his later historical review, and it puts the tritium where an autoradiograph can map it.

What it claims

01A 2 kilojoule Mather-type plasma focus device was used to deuterate the top end surface of its central titanium electrode, and the tip was found to develop at least a few tens of microcuries of tritium after several plasma focus discharges. The device is driven by a 28 microfarad, low-inductance capacitor bank charged to 12 kilovolts, firing into a chamber filled with deuterium at 100 to 2000 pascals; the pinch it forms reaches about ten to the twenty-fifth ions per cubic metre and ten million kelvin.Abstract; sections Plasma Focus Device and Its Operation
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02The tritium was measured with a one-millimetre NaI detector counting titanium K X-rays in a six-kilovolt window centred at five kilovolts, calibrated against a tritiated titanium target of 76 plus or minus 8 millicuries, with a threshold sensitivity near 0.2 microcuries. Electrode TA1, given about fifty normal-polarity shots and ten reverse-polarity shots, measured 392 plus or minus 90 microcuries five weeks after the run. Electrode TA2, twenty-five normal shots, gave 8.5 plus or minus 1.7 microcuries; electrode TA6, twenty-five reverse-polarity shots, gave 2.0 plus or minus 0.5.Section Measurement of Tritium Activity; Table I
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03Neither the tritium impurity level in the deuterium gas nor the tritium branch of the deuterium-deuterium reactions the machine is known to run can account for the activity. The neutron yield was about ten million per shot, so with at most a hundred shots no more than about a thousand million tritium atoms could have been produced by ordinary beam-target fusion, and expecting all of them to be absorbed into the electrode is already unrealistic. The electrodes carried between a hundred million million and ten thousand million million atoms. The deuterium cylinder used for the later electrodes was assayed and held no more than 0.72 microcuries per litre.Abstract; sections Neutron Yield Measurement and Results, Discussion, and Conclusions
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04Autoradiography turns the bulk activity into a map. A 66-hour exposure of electrode TA1, taken five weeks after the shots, produced a strong image showing a large number of randomly distributed spots, that is, localized tritium-bearing sites. Two kinds of structure are visible: sharp worm-like lines made by beta particles leaving the surface, and diffuse spots attributed to soft X-rays from deeper layers. The image has been reproduced several times since, with no noticeable loss of resolution or clarity after months.Sections Autoradiography and Results, Discussion, and Conclusions; Figure 2
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05Geometry and material both matter, which is the practical finding for anyone building the next device. A titanium electrode machined with a central two-centimetre depression developed no activity at all, and electrodes of aluminium, brass, stainless steel and tungsten gave no autoradiographic image, so the authors conclude that the proximity of the surface being exposed to the plasma focus plays an important role in the sequence of events. Reversing the bank polarity to steer the deuteron beam onto the electrode did not particularly improve tritium production.Sections Experiment and Results, Discussion, and Conclusions
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06What to watch: the authors name the measurement that would settle the mechanism and say they are building the instrument for it. The temporal variation of neutron yield and tritium activity is to be studied systematically in future experiments, using an in-situ low-energy beta counter under fabrication together with an on-line computer running variable channel width and multiscaling acquisition, so that a burst and the tritium it leaves can be tied to the same shot.Section Results, Discussion, and Conclusions, closing paragraph
What to watch

The way in

https://doi.org/10.13182/fst91-a29374SOURCE REACHED AND READ IN FULL. Published as Fusion Technology volume 19, page 391, 1991, the journal of the American Nuclear Society now distributed by Taylor and Francis under Informa UK Limited; the version of record is closed and Unpaywall and OpenAlex report no open deposit on 2026-09-08. The authors’ paper is posted in full by LENR-CANR at lenr-canr.org/acrobat/RoutRKdetectiono.pdf, and that seven-page copy was downloaded and read for this sheet on 2026-09-08. It carries no Creative Commons statement, so no text of it is reproduced here; the summary, the claims and every locator come from that reading and use the paper’s own section headings, table and figure numbers. Affiliation as printed: R. K. Rout, M. Srinivasan, A. Shyam and V. Chitra, Neutron Physics Division, Bhabha Atomic Research Centre, Trombay, Bombay 400 085, India. Keywords as printed: plasma focus, cold fusion, tritium measurements.

How to cite it

R. K. Rout, M. Srinivasan, A. Shyam, V. Chitra (1991) Detection of High Tritium Activity on the Central Titanium Electrode of a Plasma Focus Device. doi:10.13182/fst91-a29374

Where it sits in the curriculum

Lattice confinement fusion Plasmoids, charge clusters and the orbs