Experiments in a deep Colorado mine indicate that nuclear fusion can take place at low temperatures, Brigham Young University physicist Steven E. Jones said Wednesday.

But the amount of fusion taking place is infinitesimal and sporadic. Jones said the reaction is "exciting scientifically" but has no practical application at the present time.Jones also said his experiments refute claims made by University of Utah scientists B. Stanley Pons and Martin Fleischmann more than a year ago that excess heat observed in their experiments was due to "cold fusion" because the level of neutrons detected is "far too small."

Jones criticized cold-fusion data reported by Pons and Fleischmann last year. He said data does not support the amount of excess heat the two scientists claim was generated in experiments they conducted.

"If you look at what we are sure of, which is that E

mc2, this equation implies that . . . whenever you produce heat there has to be some mass changes (products created)," Jones said. "But look at this darn equals sign. Equals, you know. It is not enough to say, `Well I got a few neutrons so the heat is caused by fusion.' . . . You have to ask how much (neutrons)."

The gap between the heat produced in the Pons experiment and the neutrons detected is equivalent to the difference that exists between "a dollar bill and the national debt," Jones said. "I can't comprehend that gap. It's huge."

Still, Jones said his experiments show that some phenomenon is occurring that results in sporadic, low levels of nuclear fusion at room temperatures.

Jones, who purposely avoided using the words "cold fusion" during his presentation, and two other researchers conducted experiments this summer in a Pueblo, Colo., lead mine one-third of a mile below the Earth's surface to rule out the possibility that observed reactions are due to cosmic rays.

The researchers also checked detection equipment to rule out the possibility that spurious signals - such as noise or electromagnetic interference - is causing the reactions.

The other two researchers that worked with Jones are Kevin Wolf of Texas A&M University and Howard Menlove of Los Alamos National Laboratory. Some 16 other scientists are also collaborating with Jones.

Jones used a segmented, proportional detection device to measure neutrons produced in a fusion reaction. The detector is an 18-inch-long pressurized stainless-steel bottle filled with titanium chips and deuterium gas; helium gas in the cylinder captures any neutrons produced in a reaction. Reactions are measured by an optical readout system and electronic circuitry attached to the detector.

The detector is 34 percent efficient; in comparison, a detector used in experiments Jones reported more than a year ago in the scientific journal Nature was only 1 percent efficient.

The detector recorded two large bursts of neutrons underground and three small bursts of neutrons above ground in experiments at the Colorado School of Mines, Jones said. The reaction produced 2.5 MeV's (million electron volts) of energy, indicative of nuclear fusion.

The experiments provide strong evidence that the reactions observed are not due to spurious signals, Jones said. But the reactions Jones observed in his experiments are "rare. . . . It takes patience and courage to look for them.

"There does seem to be some component of fusion because . . . there are not just neutrons here, there is also the energy," Jones said. "I don't know of anything else in nature that produces (a neutron) of this energy."

If scientists discover a way to control the low levels of nuclear fusion produced in experiments like Jones', the resulting neutrons could be used in such applications as cancer treatment and detection of plastic explosives, Jones said.

Jones' results will be published in the Journal of Fusion Energy and the Journal of Fusion Technology, both now in press.

Jones is traveling to Hawaii and Kamioka, Japan, next month to conduct similar experiments.