The results of a double-blind, cold fusion experiment are reported, in which six laboratories measured the helium content of five identically shaped 2-mm-diam × 10-cm-long palladium rods supplied by Fleischmann and Pons. Three rods were initially implanted with 4He. Before analysis, three of the rods had served as cathodes during electrolysis in cold fusion experiments: two in 0.1 M LiOD, and one in 0.1 M LiOH. The other two, one implanted and one not, served as references. The major observations are as follows:

  1. All the materials, including the as-received palladium stock, contained easily measured quantities of 4He, well above amounts normally found in high-purity palladium.
  2. The 4He could be totally removed from at least two of the materials, including the as-received palladium stock, by surface etching the samples to a depth of ∼25 µm.
  3. Helium implanted by alpha-particle bombardment remained in the electrodes throughout the electrolysis.
  4. No 3He was measured above detection limits in any of the materials by any of the six laboratories.
It cannot be proven that the minimal excess heating in one of the rods reported by Fleischmann and Pons can be attributed to the formation of 4He, although the possibility that some 4He could have formed during electrolysis cannot be ruled out. If 4He were generated, the mechanism must be surface related, not bulk related. No attempt was made to measure any helium or tritium that might have left the cathode surface as gas during electrolysis. The results presented cannot, unfortunately, confirm the existence or nonexistence of cold fusion via helium production. However, they provide a basis for follow-on experiments that should lead to a final conclusion.