Follow-up Report of EarthTech's PACA Experimentation

Initial Report

Introduction

In May of 2007, we began a replication attempt of a phenomenon reported by Richard Oriani - the creation of tracks in CR-39, a nuclear track detector, placed within an electrolysis experiment.  Oriani further claims these tracks to be direct evidence of nuclear reactions occurring in the cell.  Our goals were to replicate the creation of tracks and to determine their origin.

We succeeded in replicating Oriani's observations only when using o-rings from his lab.  The recognition of the vital importance of the o-rings and the fact that they remained active after electrolysis led us to consider the possibility that the o-rings were contaminated with radioactive material.

In October of 2007, we received additional o-rings from Richard Oriani, one of which was an order of magnitude more active than previous o-rings.  Oriani also sent us a piece of CR-39 that had been exposed to this o-ring and subsequently etched.  The CR-39 contained numerous tracks in a pattern coincident with the o-ring.  

Verifying the Activity of the O-ring

The new hot o-ring (RO-II) was placed on CR-39 for 2 days.  This produced a clear o-ring pattern of tracks on the CR-39.  It was noted that the pattern of tracks stopped abruptly at the perimeter while gradually falling in number on the inside.  

After measuring the diameter of the ring of tracks, we came to the conclusion that the o-ring was only active on the inner surface.  This was verified by exposing CR-39 to small sections of the o-ring set on end.  Additionally, it was verified that the tracks originated from the surface of the o-ring and not from the interior bulk material.

Alpha Spectroscopy

We used an Ortec Diad II sold surface barrier (SSB) detector in this testing.  The data sheet for this device can be found here.

Previous attempts to collect alpha spectra were not very successful.  Our first attempts involved taking spectra in air which reduced the energy of alphas being emitted from the o-rings by a variable amount dependent on the air path length.  We constructed a vacuum chamber that elminatedf this problem.  The first o-ring we counted (C1) produced so few counts that it was difficult to identify.  We did, however, see a similarity between the o-ring spectrum and that from a thorium mantle.

We improved our standard thorium spectrum by making thin samples to reduce self absorption.  This was accomplished by making solutions of thorium samples and drying drops of the solution on a substrate.  We used two different specimens of thorium.  The first was a piece of thorium metal of unknown pedigree and history.  It has been used in various scientific laboratories for the past 50 years.  The second specimen was a piece of thorianite, a mineral that is mostly composed of ThO₂.

The new o-ring, RO-II, proved to be a much better candidate for this type of alpha spectroscopy than C1.  The higher activity level provided an adequate number of counts over a shorter period of time.

The o-ring spectrum bears a remarkable resembles to the two thorium spectra.  The main difference is that the o-ring spectrum is missing a peak at 4 MeV which corresponds to Th-232.  This is the naturally occurring thorium isotope.  However, as we do not know the exact history of the o-rings, it is not inconceivable that they are contaminated with Th-228, which has a half life of 1.9 years.  Below is a table of Th-232 and its progeny.  The branching and energies listed are for alphas only and include only the branches over 1%.

Table 1:  Thorium Decay Chain

Another phenomenon reported by Oriani was also investigated.  When an o-ring is placed on a piece of CR-39 (called a residual activity experiment), tracks appear in the middle of the area subtended by the o-ring.  Oriani claims that such tracks cannot be produced by ordinary contamination because alphas emitted by the o-ring could not penetrate the plastic in such a way as to produce a track after etching.  He states that the angle of entry is too great and therefore the path of damage caused by the particle will be entirely etched away.  He verified this by purposely contaminated an o-ring with a solution of uranium acetate.  This o-ring did not produce tracks in the middle of the CR-39.

Our investigation showed that tracks appearing in the middle of the CR-39 can in fact be explained as another symptom of thorium contamination on the o-ring.

We contaminated an o-ring with a solution made from thorium metal dissolved in aqua regia and placed it on a piece of CR-39 (wrapped in aluminum foil) for about 18 hours.  The track density in the field of view of figure 6 (one square is 1.5 mm) is about 1,000 tracks/cm² – far greater than the background of less than 10 tracks/cm².

Fig 7:  Several tracks in the middle of the area subtended by the o-ring (200x)

These results are in disagreement with Oriani's results.  However, different radioisotopes were used while conducting the tests.

Commercially available uranium acetate is made from depleted uranium and therefore does not have an equilibrium of its progeny.  Virtually all the alphas produced by this substance are 4.2 MeV (those from U-238).  The lack of progeny is illustrated by the graph below which shows that it takes many thousands of years after processing for progeny with higher energy alphas (such as the 7.67 MeV alpha from Po-214) to accumulate to significant levels.

On the other hand, the alpha spectrum of our thorium metal sample shows that it contains significant quantities of its progeny, including Po-212 which produces an 8.78 MeV alpha.  This high energy alpha can penetrate much deeper into the CR-39 than the 4.2 MeV alpha from uranium acetate.

One of our colleagues has suggested that the above reasoning is faulty.  He states that a track could not be formed from a particle entering at such an oblique angle no matter the energy.  Etching occurs preferentially in damaged areas and this establishes a critical angle at which a particle will cause a track.  He asserts that 14° is far too steep for anything to make a track.  We have not yet fully explored this suggestion and we are still discussing the issue.

However, he does make another argument for the cause of tracks appearing in the middle of the CR-39.  The thorium decay chain contains radon, a gas, which could migrate to middle of the CR-39 before decaying.  This would also explain why many of the tracks seen in the middle are close to round, indicating that the particle entered nearly normal to the surface.

Summary

The results of the testing conducted are consistent with the o-ring being contaminated with thorium and its progeny.  The alpha spectrum identifies all alpha emitting decay products of Th-228.  Contamination from this isotope and its progeny also explain a previously mysterious phenomenon - the appearance of tracks in the middle of the CR-39.

In view of this evidence, the contamination hypothesis seems more likely than the hypothesis that the tracks are a result of low-energy nuclear reactions occurring during electrolysis.

1.  http://www.wise-uranium.org/rup.html